Bulletin of the American Physical Society
2019 Joint Fall Meeting of the Texas Sections of APS, AAPT and Zone 13 of the SPS
Volume 64, Number 18
Friday–Saturday, October 25–26, 2019; Lubbock, Texas
Session A01: Poster Session |
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Room: Student Union Building Matador Room |
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A01.00001: Development of low-cost cryogenic temperature measurement system using Arduino microcontroller. Woong Sung Lee The implementation of a cryogenic temperature measurement system is an expensive procedure for an instructional laboratory. We present a simple, low-cost, and computer-controlled cryogenic temperature measurement system to replace highly-developed commercial solutions. An Arduino microcontroller measures the voltage across a silicon diode which is connected to a constant current source circuit. Then, a program inside the microcontroller calculates the temperature. Additionally, we present a graphical user interface based on the open-source processing language. Our performance test shows that the system works at a reasonable accuracy from 297.15 K (typical room temperature) down to 77 K (liquid nitrogen temperature). [Preview Abstract] |
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A01.00002: Effect of localized mechanical vibration assisted self-assembly of particles on inherent defects. Sayantan Das Thin films on surfaces formed of microparticles and nanoparticles is of huge interest for its applicability in various industries. However, bottom up technology like directed self-assembly to create thin films of particles suffer from inherent defects that occur with unpredictable misaligned grain boundaries and point defects. Limiting the usability in applications requiring precision. We demonstrate the effect of using localized mechanical vibration during directed self-assembly process on reducing the inherent defects in particle thin films. Initial studies include polystyrene nanoparticles of diameter of 600 nm and resin microparticles of diameter 0.86 mm. Controlled and localized mechanical vibration were obtained via several cost efficient piezo ceramic elements placed strategically underneath the substrate / surface during the deposition. The frequency of vibration varied from 0-200Hz with phase difference between the vibrating plates ranged from 0 to 2pi. Over 90{\%} reduction in the defects, with larger crystal domains are realized in comparison to control for both micro and nanoparticles. The phased vibration of plates underneath allowed particles to coerce together rapidly. And, the frequency of vibration within 50-100Hz and 5-50Hz, were found optimal for reducing the defects of the films from Nano-particles and microparticles, respectively. Further, numerical investigation was performed using Langevin equation for our system of particle and the results correlated with the experimental findings. \textbf{Keywords} defects; thin films; mechanical vibration; self-assembly; particles; nanoparticles; microparticles; numerical investigation; industry; scalable; [Preview Abstract] |
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A01.00003: Calculating the distance to SN 2007gr using the Expanding Photosphere Method Ryan Staten SN 2007gr is a type Ic supernova observed extensively by the Robotic Optical Transient Search Experiment (ROTSE). While the expanding photosphere method (EPM) is typically used to measure the distance to type IIP supernovae, this analysis aims to apply EPM to SN 2007gr. Although this object does not possess the hydrogen and helium envelope that is typically required for EPM, this work aims to assess the accuracy of this method of obtaining accurate cosmological distance measurements using a stripped envelope supernova. [Preview Abstract] |
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A01.00004: Implementation of microscale ZnO with controlled morphologies to study the influence of surface polarity on ZnO antibacterial action Mark Hattarki, John Reeks, Eric Davis, Tabitha Haun, Iman Ali, Shauna McGillivray, Yuri Strzhemechny Antimicrobial properties of microscale ZnO have been well documented, however a clear model of this action has not been identified. Within the hypothesis that one of the major mechanisms causing ZnO antibacterial properties is rooted in the interactions between the surface of ZnO crystals and the cell's surface, it is reasonable to assume that ZnO surface polarity may affect its antibacterial properties. We employed hydrothermal growth method to controllably synthesize ZnO particles with different relative abundances of polar vs. non-polar surfaces and subsequently investigated antibacterial assays with these microcrystalline samples. [Preview Abstract] |
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A01.00005: Calculating neutrino oscillation probabilities in matter Jedeshkeran Chandrasegaran, Preet Sharma Neutrino oscillations have been a very hot research topic in particle physics. They provide a description to the Universe we live in and give a picture as to what it was in the past and what it is currently. Neutrino oscillations are a very effective tool in understanding the very fundamental questions like cp-violation. Since neutrinos pass through anything and everything without interacting, we have calculated neutrino oscillations in matter when neutrinos pass through the earth. [Preview Abstract] |
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A01.00006: A Systematic Reconstruction and Quantification of the Lag-Luminosity Relationship in Gamma-Ray Bursts Joshua Osborne, Amir Shahmoradi Gamma-Ray Bursts (GRBs) are the most energetic explosions in the universe, releasing much of their energies, on the order of 10$^{\mathrm{52}}$ ergs, in a fraction of a second to minutes in the form of gamma rays. Two classes of GRBs have been so far confirmed to exist: the short-duration class which are due to the merger of Neutron stars and the long-duration class which are attributed to the death of supermassive stars. The light-curves of GRBs typically exhibit temporal lags at different energies, and a potential negative correlation between the intrinsic brightness and the lightcurve's lag at different energies among GRBs have been observed and hypothesized to exist. The extent to which this relationship holds however, has been the subject of debates and not fully explored, in particular, because of the lack of information about the redshifts for the majority of the observed GRBs. In this work, we attempt to further quantify the strength and the validity of this relation. We achieve our goal by first quantifying the observed spectral lags of GRBs in the largest catalog of GRBs available to this date: the BATSE catalog and second, by mapping the computed GRB lags and brightness to the cosmological rest-frame of these events. [Preview Abstract] |
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A01.00007: Identifying Magnetospheric Crossings between Northward and Southward IMF Chelsi Nelson, Michelle Bui, Christina Xing, Pauline Dredger, Fateme Bagheri, Ramon Lopez The magnetopause is the boundary between Earth's magnetosphere, controlled by Earth's magnetic field, and the magnetosheath, comprised of plasma and the solar wind. Our focus for this research was to search for satellite crossings through the magnetopause by utilizing data collected by THEMIS probes found on NASA Space Physics Data Facility's CDAWeb. In this presentation, we explain how to identify a probe crossing through the magnetopause. A clear crossing can be defined when the ion density sharply increases or decreases and when the z-component (Bz) of the magnetic field sharply decreases or increases respectively. Increasing ion density and decreasing Bz is indicative of the spacecraft moving out of Earth's magnetosphere. The reverse also applies: THEMIS can move from the magnetosheath into the magnetosphere. The crossing was verified by looking for a sharp change in electron flux. Crossings were considered when the interplanetary magnetic field (IMF) was directed both northward and southward due to solar wind conditions. Searching for multiple satellite crossings in a given time frame can help us determine the location and properties of the magnetopause at a given moment. Identified crossings were recorded and catalogued for analysis of magnetopause activity. [Preview Abstract] |
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A01.00008: Demonstration Of Fluorescence Near the K-Absorption Edge in Back-Reflection Laue Nicholas Summerfield, Rebecca Forrest In Laue diffraction, the bremsstrahlung x-ray spectrum is used to obtain a diffraction image of a sample on the atomic scale. When using the bremsstrahlung beam on a sample, the sample may fluoresce which will hurt the contrast of the Laue diffraction image, however this phenomena can also be utilized in fields such as x-ray spectroscopy. The interaction between a sample material and incoming x-rays is specific to the sample material as every element has a unique absorption vs energy relationship and k-absorption edge. Different x-ray energies around the sample's absorption edge will result in the sample releasing a different flux of photons as it fluoresces. Changing the incoming x-ray intensity by changing the filament current, the energies of the x-rays are consistent, however the magnitude of fluorescence will change. Changing the voltage of the x-ray source will change this energy distribution and the intensity of the bremsstrahlung beam. In this poster, back-reflection Laue is used to capture the fluorescence of molybdenum (Mo), antimony (Sb), and silver (Ag) about their absorption edges at different x-ray source current and voltages. [Preview Abstract] |
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A01.00009: An Exploration of Cosmological Models which ease the Hubble Constant Tension Clare Bacak, Jacob Moldenhauer The universe is expanding, but the two methods of measuring the rate of this expansion, or Hubble Constant H$_{\mathrm{0}}$, are in contention with one another. Local Cepheid variables and the cosmic microwave background (CMB) power spectrum, produce expansion rates in different ways. The unresolved tension could be an indication there may be another model of physics. We use the Monte Carlo Markov Chain program CosmoMC to test the following models:$\omega $CDM model allows the density of dark energy to vary between -1 and -3; nCDM allows the flavor of neutrinos to vary from 2 to 7; MPC is a modified gravitational model, and we use LCDM as control. Finally, we compare our tests to others found in the literature and comment on future tests. [Preview Abstract] |
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A01.00010: Calculating Neutrino Oscillations in Matter Jedeshkeran Chandrasegaran, Preet Sharma Neutrino Oscillations are a very important aspect in understanding the properties of neutrinos. Neutrinos come in three flavors, electron-neutrino, muon-neutrino and tau neutrino. As these neutrinos travel long distances across vacuum or matter they change flavors and oscillate into other flavors. We will present the neutrino oscillation probabilities in matter. [Preview Abstract] |
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A01.00011: Creating Physics Curriculum Outside of the Traditional Classroom Setting Heather Perkovich Physics Unlimited is an non-profit organization~led~by graduates of Princeton University, with many different aspects to the organization. Physics Unlimited's Moonshot Program is a new~initiative~designed to target~underrepresented~audiences and inspire them to become interested in physics. In a 7 week period, we designed and developed curriculum for 12 physics lessons, which will be taught over the course of 12 weeks~in a one hour session each week.~Each lesson is uniquely designed to capture physics in everyday life to make physics a relatable topic to every individual. As a content creator of the physics lessons that~will be~used~in the coming months~(and~in~the future), I~was challenged~to~create appealing lessons to the intended audience.~The~School of Re-Entry at the~Boston Pre-Release Center~(BPRC)~helps inmates prepare for life outside of prison and educates~students in a diverse range of subjects, providing a new path in life. The pre-release center in Boston will be the first place~where~our physics lessons will be used, with the intention~that the~program~will expand to include other similar centers~and different target audiences across the U.S.~ [Preview Abstract] |
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A01.00012: Semi-hemispherical lens optical system for surface plasmon resonance measurements---an undergraduate research project Facundo Soria, Douglas Zinn, Suresh Sharma We discuss the design and setup of a semi hemispherical lens based optical system for carrying out surface plasmon resonance (SPR) measurements. Because of extremely high sensitivity of SPR to changes in the refractive index, the technique is used widely for applications in physics, chemistry, and biotechnology. Often the Kretschmann or Otto configuration optical systems are used. In one type of application, the relative intensity of reflected beam is measured as a function of the incidence angle around the resonance angle, which shifts with the refractive index of the material........$^{\mathrm{[1]}}$ The focus of this undergraduate research project was to design, setup, and study the performance of a semi-hemispherical lens based system, which uses high resolution digital microscope to collect reflectivity data over a wide range of angles in \textit{one-shot} without the need for angle scans. This minimizes the time and effort for carrying out SPR measurements................$^{\mathrm{[2]}}$ \begin{enumerate} \item S. C. Sharma, in Advances in Sensors; \underline {http://www.sensorsportal.com/HTML/BOOKSTORE/Advances} in Sensors Reviews Vol 5.pdf, IFSA Publishing, Barcelona, Spain 2019 \item Dehmel et al., Appl. Phys. Lettes., 111, 201102 (2017) \end{enumerate} [Preview Abstract] |
(Author Not Attending)
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A01.00013: Electric Field Simulation of the Field Cage for Deep Underground Neutrino Experiment Archit Jaiswal The Deep Underground Neutrino Experiment (DUNE) is the U.S. flagship experiment being designed to study the characteristics of neutrinos which make up a quarter of the fundamental particle map in 2026. This subatomic particle can reveal various unsolved mysteries like the existence of matter in the universe. In DUNE neutrino interactions will be captured inside a 12m x 12m x 60m active volume time projection chamber using liquid argon as the medium. The ionization electrons due to the traversing charged particles from neutrino interactions drift through the liquid argon and detected. The field cage which is constructed by modules made of aluminum strips and fiber-glass I-beams provides a uniform electric field for these electrons to drift at the uniform speed. After analyzing the performance of the previous design of field cage used in a prototype detector, several improvements were made to the field cage design for DUNE. Before the actual construction and test of field cage, we are simulating the electric field across the new field cage design. In this talk, I would be describing the new design of the field cage and the resulting electric field map of the new field cage design. [Preview Abstract] |
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A01.00014: Differences in Radiative Heat Transfer through Filtered Glass Taylor Zimmerman, Edward Hamilton The aim of this experiment was to determine which filters on glass would help reduce the termperature in a car exposed to solar heating. A plywood box was built and tested with different filters and screens using the same thermal energy input, with results showing the relative efficacy of each at controlling the rise in temperature. A reflective screen using crumpled aluminum foil was found to give the best reduction in heating. [Preview Abstract] |
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A01.00015: GRBs with afterglow plateaus during LIGO S6/O1/O2/O3 runs Deven Bhakta Several Gamma-ray Burst (GRB) afterglow light curves show a so-called “plateau” phase in the X-rays. Theoretical models predict that a long-lived central engine, such as a highly magnetized neutron star (magnetar), could power this plateau phase by injecting energy into the afterglow shock. Under the hypothesis that the newly-born magnetar is secularly unstable, its presence could be probed directly by searching for long-lived gravitational waves (GWs) during the plateau. In this work, we estimate the number of GRBs that could be potential targets for further long-duration GW signal searches. We considered all GRBs detected by the Swift Burst Alert Telescope (BAT) from April 2019 to October 1st, corresponding to advanced LIGO third observing run (O3). For completeness, we also extended our analysis to the past runs, advanced LIGO first and second observing runs (O1, O2) and initial LIGO 6th Science run (S6). Overall, we estimate that in O2, O1 and S6 each, ≈ 10\% of Swift-triggered GRBs show an X-ray plateau with at least 1000 s of double coincidence time from the LIGO detectors. Our initial analysis for O3 is compatible with our results from the past runs. [Preview Abstract] |
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A01.00016: Fitting and analysis of radio afterglow light curves from GW sources Arvind Balasubramanian Gravitational Wave observations have given us yet another way to understand the cosmos. Gravitational wave events are often accompanied by emission from across the electromagnetic (EM) spectrum. EM follow up observations help in pushing the boundaries of our understanding of gravitational physics, nucleosynthesis and cosmology. GW170817 is the first detection of gravitational waves and light from the merger of two neutron stars. Radio observations, in particular, and analysis of the broad-band afterglow of GW170817 in general, led to verification of the predictions of various jet models. These models are parametrized by a large number of correlated parameters. Fitting them requires a robust tool like affine invariant Markov Chain Monte Carlo (MCMC) simulations, that can be used to obtain the best fit parameters and the errors associated with them. This poster presents preliminary testing of a dedicated MCMC code, and some ongoing work to model the expected very-late-time radio emission of GW170817 arising from the interaction between the neutron-rich ejecta and the surrounding interstellar medium. [Preview Abstract] |
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A01.00017: Analysis of Gamma Ray Bursts with Measured Redshift with Respect to Flux/Fluence and Spatial Distribution Samuel Tessema It is currently accepted that there are two types of gamma-ray bursts (GRBs): short/hard ones and long/soft ones with the possibility of a third, ultra-long group arising from recent data.~ The long GRBs are associated with supernovae, where the short ones arise from macronovae (or kilonovae). Kilonovae can arise from the merging of two neutron-stars or more massive black holes. Therefore, the study of gamma-ray bursts, especially short ones, and the study of massive binaries are strongly linked. This investigation focuses on the measured redshifts of all GRBs detected to date. We find an intriguing result such that an inverse relationship appears where GRBs which appear fainter can be at smaller distances. Our results, therefore, resemble those of Meszaros et al (2011), but with an up-to-date collection of GRB samples. In effect, the former result is supported by the analysis of the newly collected data. [Preview Abstract] |
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A01.00018: Radio Remnants Of Nearby Off-AXIS GAMMA-RAY Bursts - PART I: Observational Results Connor Grandorf, Heather Harbin, Priyadarshini Rajkumar, Alessandra Corsi The remarkable multi-messenger discovery of the binary neutron star merger GW170817 by the LIGO/Virgo gravitational-wave (GW) detector networks has marked the start of a new era in astrophysics. In addition to confirming the predictions of Einstein's general theory of relativity, the joint EM/GW discovery of GW170817 has given us new insight into the angular structure of gamma-ray burst (GRB) jets, and into the possible existence of a nearby population of bursts hidden within those with unknown distances. Building upon the new information gained from GW170817/GRB170817A, we present here late-time radio observations of a sample of 8 short GRBs with unknown distances in the NASA/Swift sample aimed at searching for potential radio emission from nearby GW170817-like ejecta. While definitive results require further observations, we have found several promising candidates for radio counterparts to these GRBs that may unveil, for the very first time, a missing population of nearby short GRBs. [Preview Abstract] |
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A01.00019: Kilonova Emissions -- Particle-In-Cell Simulations of Mildly Relativistic Outflows. Mohira Rassel Collisionless shocks are ubiquitous in astrophysical plasmas, and are observed to be the sites of very high energy particles (which then radiate photons over a wide range of energies). ~A long-standing, unsolved problems in high energy astrophysics how magnetic fields are generated in these shocks, and how these fields relate to the process of particle acceleration. ~Particle-in-cell codes are ideally suited to address this question and previous work has looked at cases of magnetic field generation and particle acceleration in both highly relativistic and non-relativistic shocks.~~The aim of this project is to examine shock development, magnetic field generation and particle acceleration in the case of~\textit{mildly~}relativistic shocks, which are expected when the tidal ejecta of neutron star mergers shocks with the external medium. Using LANL's VPIC~(vector particle-in-cell), we have run simulations of such mildly-relativistic, collisionless, (initially unmagnetized) plasmas and compute the resultant magnetic fields and particle energy spectra.~ We show~the effects of varying plasma conditions, as well as explore the~validity of using different and often unrealistic proton~to electron mass ratios in VPIC.~ Our results have implications for observing late-time electromagnetic counterparts to gravitational wave detections of neutron star mergers. [Preview Abstract] |
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A01.00020: Detection of Hα emitters within the IPHAS field of view Matteo Fratta I present a list of likely H$\alpha$ emitters among the sources in the INT Photometric H$\alpha$ Survey of the Northern Galactic Plane (IPHAS) field of view. Out of 7373236 objects, 17272 have been highlighted as emitters, in the H$\alpha$ narrow band. For each of these objects, I calculated a significance parameter which provides a quantitative degree of confidence that the given source is a true emitter, with reference to an associated group of similar objects. In this way, future users can choose between applying a more conservative cut rather then opting for completeness, or vice versa. In this study, I used a cross-matched catalog between Gaia DR2 and IPHAS DR2; this provided me with, besides the r, i and H$\alpha$ IPHAS bands, also the Gaia Bp, Rp and M$_G$ colors, along with the distances between the sources and us. I could then build the Bp-Rp VS M$_G$ Color-Magnitude Diagram, which allowed me to identify which population each source most likely belongs to. [Preview Abstract] |
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A01.00021: The Peak Optical Luminosity versus the Orbital Period of Black Hole X-ray Binaries Victoria Blackmon, Thomas Maccarone We compare the peak optical luminosity with the orbital period for a sample of 21 stellar-mass black hole candidates with good measurements of both quantities. We find that the peak absolute magnitude for the outbursts follows a relation with $M_V=−3.07 {\rm log} P + 2.99$, which corresponds to a $L_V \propto P^{1.23}$ relation. This is a similar relationship to that found for cataclysmic variables. We discuss the implications of these results for finding black hole X-ray binaries in other galaxies and in our own Galaxy with the Large Synoptic Survey Telescope and with other future large time domain surveys. [Preview Abstract] |
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A01.00022: Searching for Hidden Black Holes in APOGEE-2 David Palmore, Thomas J Maccarone, Rachael Beaton, Michael Eracleous, Arash Bahramian The Milky Way is believed to contain thousands of stellar mass black hole X-ray binaries, but only about 50 candidates are known. I discuss an examination of the APOGEE-2 data for X-ray sources in the Swift Galactic Bulge Survey region. The object HD 158902 stood out as warranting further investigation, because it showed a radial velocity discrepancy between archival data and APOGEE-2. I discuss my work in determining whether this is due to binary motions or other causes. [Preview Abstract] |
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A01.00023: Supernova Remnants TeV Gamma Ray Emission with HAWC Ramiro Torres Escobedo Supernova remnants (SNRs) have been astrophysical objects of great interest in the very high energy universe. There is evidence to suggest, that SNRs are responsible for the cosmic ray emission up to an energy $10^{15}$ eV. Gamma-rays help explore the TeV universe to study the sites where particle acceleration take place. The High Altitude Water Cherenkov Detector (HAWC), located in Sierra Negra Volcano in Puebla state, Mexico is a wide field gamma-ray observatory, capable of observing gamma rays with energies up to $\sim$ 100 TeV. Studies of gamma-rays at these energies provide a way to distinguish whether gamma-ray emission is of leptonic or hadronic origin. [Preview Abstract] |
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A01.00024: Optimizing the search for electromagnetic counterparts (EM) to Gravitational Wave (GW) events with the Liverpool Telescope (LT) Priyadarshini Rajkumar, Chris Copperwheat, Daniel Perley Our understanding of gravitational wave (GW) events is enhanced by identifying and studying their electromagnetic (EM) counterparts. For nearby GW events with a small localization uncertainty, an effective strategy is to search for new transient sources in previously catalogued galaxies, whose properties are consistent with the GW data. Even with a limited field of view, such as that of the Liverpool Telescope (LT), it is plausible to discover the EM counterparts using an efficient observational strategy. But because many galaxies must be observed and the EM counterparts are faint and fade rapidly, a reliable automatic procedure is crucial to schedule observations. To meet these challenges, we designed an algorithm in Python that uses a catalogue of nearby galaxies and the 3D GW localization map to create a prioritized list of galaxies based on GW error-map probability, observability, and absolute magnitude. We tested our algorithm with past GW events and, within a few minutes, obtained consistent results with previous observations. Thus, this algorithm can swiftly assist in the formulation of effective follow-up plans which should increase the probability of localizing EM counterparts. [Preview Abstract] |
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A01.00025: A Case Study of Bow Shock Current Closure Pauline Dredger, Fateme Bagheri, Ramon Lopez As solar wind propagates away from the sun, it encounters Earth’s magnetic field and slows rapidly to subsonic speeds, creating a bow shock. The compression of solar wind flow and interplanetary magnetic field (IMF) across the bow shock produces a current flowing along the shock. This current must close in part through the magnetospheric current system, either through Chapman-Ferraro current on the magnetopause, the boundary between the solar wind and Earth’s magnetic field, or through Birkeland currents flowing on open field lines, depositing energy directly into the ionosphere. We present a case study demonstrating bow shock current closure through the ionosphere, the region of plasma within Earth’s magnetic field. On August 2, 2016, IMF Bx was small, By was large and positive, Bz was strongly southward, and the magnetosonic Mach number was around three or less. AMPERE data show Birkeland currents in regions that appear to be open field lines with the current polarity consistent with closure of bow shock current. THEMIS spacecraft crossed both the bow shock and the magnetopause during this event, allowing a direct estimate of the current densities at those structures. The observed currents match the expected closure of bow shock current under the given solar wind conditions. [Preview Abstract] |
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A01.00026: Avoided Level Crossing during Ion -- Surface Interaction Bogdana Bahrim, Aris Martinez We apply the Wave-Packet Propagation method adapted to ion-surface interactions [1] to study negative hydrogen ions scattered from silver surfaces. As the ion projectile approaches the surface, the Projected Density of States (PDOS) shows an avoided crossing between the negative ion energy level and the silver surface state level located inside the band gap at the G point. We show results for the energy of the projectile as a function of the ion-surface distance, as well as a detailed study of the metal surface states and image states involved in the interaction. This work is important for Fundamental Research and has a broad range of technological applications [2, 3], such as in: Aeronautical and Space Engineering, Plasma-Wall Interactions, Film Deposition, Catalysis, Corrosion, and Scanning Tunneling Microscopy. [1] B. Bahrim, J. Stafford, B. Makarenko, Surface and Interface Analysis 50, 212 (2018). [2] R. Goswami, Physics of Plasmas 20, 082516 (2013). [3] P. R. Chalker, Surface and Coating Technology 271, 258 (2016). [Preview Abstract] |
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A01.00027: Study on the Nanoparticles Used in Treatment for Cancer Using Bio-chemical and Computational Analysis Nuo Cheng, Richard Kyung Computational biomedical simulation with nano technology is perceived as a new approach to an alternative method for future solution of cancer research. In recent years, potential solutions in cancer treatment used nano scaled carbon nanotube complexes, since they are believed to be able to stabilize the cells affected by cancer. A free-radical chain reaction capable of propagating in space is the major oxidative reaction in biomembranes. In the light of the promising use of carbon nanotube complexes, this paper studies their thermodynamic safety and stability to inhibit the free-radical chain reaction which propagates in tissue space. For this purpose, we used the program Avogadro to model, optimize, and compare the resulting molecular energy of the clusters. Various types of Carbon Nanotube(CNT) derivatives were tested for their thermodynamic stabilities, which were measured through the optimized energies. The reactivity and conductivity were also measured through the dipole moments to calculate the activity level the molecule could have with other nearby molecules. Lastly, electrostatic potential maps were utilized to visualize the polarization and assess the reactivity level of each molecule. [Preview Abstract] |
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A01.00028: Electromagnetic Shielding for Low Level Biological Signal Detection. Sarah Evans, Mary Fox, Arthur Sweeney, Jacob Moldenhauer, Drew Stenesen Electromagnetic interference makes the detection of low-level electrophysiological signals difficult without shielding. This study was conducted to limit the noise detected by a DC amplifier to better collect electroretinogram (ERG) data of fruit flies [\textit{Drosophila}]. $~$A Faraday Cage was built with 1.24mm spacing copper mesh. The cage was optimized for shielding ambient electromagnetic interference of 10GHz and smaller. Inside the cage, a neutral ground connection was added, so low level biological signals (ERGs) were the only signals picked up within by the highly sensitive probes. Coaxial cables connected components of the experiment within the cage to those outside of it. The cables ensured that ambient signals would be blocked from the information leaving the cage. \quad The ERGs collected within the cage were isolated to the signals given by the photoreceptors of the fruit flies. Previously, little information was discernible because of the excess noise. With these shielding methods, the acceptable depiction of the fruit fly ERG is distinguishable. [Preview Abstract] |
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A01.00029: ParaMonte: A high-performance parallel library for Monte Carlo optimization, sampling, and integration Amir Shahmoradi, Fatemeh Bagheri At the foundation of predictive science lies the scientific methodology, which involves multiple steps of observational data collection, developing testable hypotheses, and making predictions. Once a scientific theory is developed, it can be cast into a mathematical model whose parameters have to be fit via observational data. This leads to the formulation of a mathematical objective function for the problem at hand, which has to be then optimized to find the best-fit parameters of the model or sampled to quantify the uncertainties associated with the parameters, or integrated to assess the performance of the model. Toward this goal, a highly customizable, user-friendly high-performance parallel Monte Carlo optimizer, sampler, and integrator library is presented here which, can be used on a variety of platforms with single to many-core processors, with interfaces to popular programming languages including Python, and C/C$++$/Fortran. In particular, we discuss the parallel implementation of a variant of Markov Chain Monte Carlo known as Delayed Rejection Adaptive Metrolpolis (DRAM) and its scalability. [Preview Abstract] |
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A01.00030: Abstract Withdrawn
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A01.00031: Transition Probabilities for a Relativistic One-Electron Atom Gerardo Gonzalez, S.A. Alexander Using Variational Monte Carlo methods we have calculated trial wave function forms for a number of one-electrons atoms with Z$=$92. In order to incorporate relativistic effects, our trial wave functions satisfy both the 2-component Dirac equation and the 4-component Dirac equation. With these trial wave functions we have calculated a number of simple expectation values as well as several M1 and E1 transition probabilities. We compare our results with those of generated by other methods. [Preview Abstract] |
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A01.00032: Probing the stability of Shastry Sutherland lattice in Er2Pd2Sn and Er2Pd2In Gicela Saucedo Salas, Baidyanath Sahu, Andre Strydom, Harikrishnan Nair The group of 221 compounds crystalizing in the Mo2FeB2 structure type, more commonly known as R2T2X intermetallic (R $=$ rare earth, T $=$ transition metal, X $=$main group), have been reinvestigated recently owing to the spin liquid state in the underlying Shastry Sutherland lattice (SSL) formed by the R [1, 2]. Our motivation in investigating this compound is to explore the interplay of frustration and quantum criticality. The present study we have selected less-investigated Er2Pd2In and Er2Pd2Sn. X-ray powder diffraction studies and subsequent Rietveld refinements confirmed that the compounds were phase-pure and crystallized in the tetragonal Mo2FeB2 structure. Both the compounds obeyed Curie-Weiss law in the paramagnetic regime, as judged from magnetic susceptibility data, which indicated antiferromagnetism. Specific heat data on both the compounds revealed a double peak indicating complex magnetic structure and phase transitions. We will present a detailed analysis of the magnetization and specific heat on both Er2Pd2(Sn/In) and motivate our future planned neutron diffraction experiment to determine the magnetic structure of these SSL compounds to probe for novel magnetic phases. [Preview Abstract] |
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A01.00033: A Resonance Tuning of Localized Surface Phonon Polaritons on Hexagonal Boron Nitride Yejin Kwon, Myoung-Hwan Kim Metasurfaces are sub-wavelength patterned layer which interact with light and alter optical responses. In particular, gradient optical metasurfaces have been used to control a wavefront of light in free space and in optical waveguides. However, a control of light on two-dimensional surface has been challenging because of the high optical power loss from metallic nanostructures. In recent years, we have chosen polar dielectrics as a metasurfaces platform because the polar dielectrics have a low optical power loss and a high coupling efficiency to the light from ionic crystals. We classified polar dielectrics into two groups (bulks and two-dimensional materials) depending on the evanescent field characters of surface waves of the light on polar dielectrics. In this work, we propose metasurfaces platform made of two-dimensional hexagonal boron nitride. We have searched for a localized surface phonon resonances by designing the device using full wave simulation with the fintie-difference time-domain method. We studied two different geometries; metal/dielectric multilayer boundary (1) underneath the polar dielectrics and (2) on the polar dielectrics. [Preview Abstract] |
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A01.00034: Transport study of Superconductor - Graphene - Superconductor system Vivek Kakani, Xurui Zhang, Elizabeth Zhou, Xiaoyan Shi Probing interactions present in a coexisting quantum hall and superconducting state has proven to be elusive. In this work, encapsulated graphene contacted by superconducting material is proximity coupled attempting to realize this unique state. Magnetotransport study of the device at low temperatures has revealed signatures of interesting quantum oscillations and Andreev reflection at the metal-superconductor junction. [Preview Abstract] |
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A01.00035: Strategies to Improve Plant Productivity by Increasing the Activity of Organic Micronutrients in Soils Hojun Yoo, Richard Kyung Organic farming is a sustainable way of agriculture. The micronutrient homeostasis in organic and hydroponic farming is currently emerging as a key factor in maintaining plant health and preventing nutrient deficiency. Recently, micronutrient chelation through various molecules has been studied to be a potential therapeutic treatment for nutrient deficiency in plants. These molecules have the ability to selectively chelate micronutrient molecules into the plant cell to increase the micronutrient level and thus can be used to prevent the development of irregular yellowing and leaf deformities. In this research, a computational method employing quantum chemistry was used to model various organic hydroponic fertilizer or chelators that are potential candidates for the chelation in organic farming. The molecules were assessed for thermodynamic stability, reactivity, and polarization. This paper aims to model and investigate the optimal design for such nutrients that can be utilized in potential organic and hydroponic farming. Also this paper studies how local governments can provide technical support for the development of organic agriculture such as organic hydroponic fertilizer and eco-friendly pest repellents. [Preview Abstract] |
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A01.00036: Position Reconstruction in Plastic Scintillator John Rabaey, Will Flanagan, Aidan Medcalf The time of flight system of the NOvA Test Beam experiment at Fermi National Accelerator Laboratory in Batavia, IL relies on high-precision particle timing. However, uncertainty with regard to the geometrical location of a particle hit in scintillator limits time resolution. A closed-form mathematical formula has been derived for calculating the position of a particle hit in plastic scintillator, given the timestamps of four separate pulses from photomultipliers placed at the corners of a scintillator square. A Strontium-90 gamma ray source has been used to measure the position resolution of the scintillator under the new formula and determine whether position reconstruction can provide an accurate time-correction to account for geometrical differences between particle hits. [Preview Abstract] |
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A01.00037: High Resolution Muon Tomography using a Portable Prototype Muon Telescope Sadman Ahmed Shanto, Shuichi Kunori, Nural Akchurin, Raul Perez Jr, Samuel Cano, Mohammad Moosajee, Cristobal Moreno We aim to develop a portable muon detector with an excellent spatial resolution that will be able to image large structures in detail. Muons are weakly interacting elementary particles that readily pass through objects, losing some of their energy in the process. Muon tomography is a technique that exploits this phenomenon to construct images of large objects of interest, such as volcanoes, buildings, and pyramids. The present prototype comprises a two-layered system of scintillator bars, optical system with Winston cones, silicon photomultipliers (SiPMs), readout electronics, and a network of Arduinos. The cosmic muons produce scintillations as they pass through the scintillators and the Winston cones transport these photons to the SiPMs where they are converted into electrical signals. These signals, in turn, are digitized and transmitted to a local computer. This system is mounted on a wheeled cart that spans an area of approximately 90 cm by 180 cm and can be rotated \textpm 90 degrees to the vertical. We are presently able to reconstruct 2-D images of large objects with an angular resolution of 50 mrads. We are also testing, debugging, and analyzing the data stream and adjusting the parameters for the upgraded detector to vastly improve angular resolution. [Preview Abstract] |
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A01.00038: Radiation Damage on a Lead Glass Detector Wyatt Campbell The GlueX Experiment at the Thomas Jefferson National Accelerator Facility is constructed to search for hybrid mesons, particles made up of a gluon and a quark-antiquark pair. The electron accelerator beam is used to produce a photon beam that collides with a proton target, creating new, short-lived particles. In order to analyze the produced particles, GlueX surrounds the beam target with an array of detectors, including two calorimeters. The Forward Calorimeter (FCAL) sits in front of the target, down the beamline. Being near the photon beam line, which is a radiation source, might cause damage to the FCAL. To monitor this damage, an LED pulser monitoring system is attached to the FCAL. I analyzed data from this monitoring system to find evidence for, and to quantify, the radiation damage on the FCAL. My analysis found that there was a large amount of damage concentrated around where the beam line went through the FCAL. [Preview Abstract] |
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A01.00039: Approaching relativistic Quantum Theory via Probability Conservation Maik Reddiger, Bill Poirier The mathematical intractabilities of relativistic quantum theory are seldom traced back to outstanding conceptual problems in the foundations of quantum mechanics. This is surprising, since conceptual problems indicate a lack of proper understanding, thus impeding attempts to give a theory a firm mathematical foundation. Indeed, several scholars have raised doubts whether one of the primary objects of quantum mechanics, the wave function, deserves its privileged status, trying instead to formulate the theory in terms of a probability density function and a velocity vector field. Taking probability conservation as a fundamental postulate, these two quantities will satisfy the continuity equation. Their time evolution is then determined by other dynamical equations and constraints. This perspective on relativistic quantum theory motivates an in-depth study of the general relativistic continuity equation, granting insights into aspects of a rigorous quantum theory on curved spacetimes -- even before introducing further dynamical equations and quantities. This poster shows some of those results for the 1-body theory. Our work is part of the ongoing greater discussion pertaining to whether one can reconcile quantum phenomena with the axioms of Kolmogorovian probability theory. [Preview Abstract] |
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A01.00040: Determining and Designing a Time Of Flight Detector for the NOvA Test Beam Experiment Eniola Sobimpe The NOvA neutrino oscillation experiment is undergoing a charged particle test beam effort to gain an increased understanding of the NOvA detectors. The incident beam utilizes scintillator-based time of flight detectors to make particle identification upstream of the NOvA replica detector. Emphasis was given to the rise time, transit time, and pulse area when evaluating each prototype. This talk will give an overview of the various prototypes constructed and tests employed to choose the ideal photodetectors and scintillators for the NOvA test beam time of flight system. [Preview Abstract] |
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A01.00041: Serial Power Supply Development for ATLAS Upgrade Joshua Stewart, Joe Haley The LHC (Large Hadron Collider) near Geneva will be undergoing an upgrade in 2024 that will allow for higher luminosity data collection. The ATLAS project, in the midst of these upgrades, will also be enhancing its pixel detector modules to become more radiation tolerant. As a consequence of the spatial constraints, the modules must use a serial power supply able to deliver a constant current under varying loads. Our group has set out to provide researchers with a device to power the modules, during R{\&}D, that will simulate the conditions in the HL-LHC. [Preview Abstract] |
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A01.00042: Methods to Search for New Physics in Proton-Proton Collisions at the LHC - Same Sign Dimuon Final State for Lepton Number Violation Process. Samila Muthumuni The Standard Model (SM) of particle physics is a very successful model to explain matters and interactions of matters in the universe with quarks, leptons, vector bosons and the Higgs particle. On the other hand, SM is incomplete. For example, the model does not explain the existence of dark matter and gravitation in the universe. After the discovery of the Higgs particle in 2012, searches for dark matter, graviton and other new physics beyond the SM continued at the Large Hadron Collider (LHC). A search for new physics in proton-proton collisions at the LHC same sign dimuon final state for lepton number violation process is presented with the data collected by the CMS experiment for proton-proton collision at 13 TeV with 35.9/fb . Methods used in search for lepton number violation in proton-proton collisions at the LHC have been focused, which produce two same sign muons in the final state. The measurements of cross sections for the signal region in data and estimated backgrounds from Monte Carlo (MC) simulation for the same sign dimuon channels are consistent. No excess signal is observed in those channels. [Preview Abstract] |
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A01.00043: Domain-interface defects in crystals Christopher Layden, Branton J. Campbell Understanding the microscopic properties of multi-domain single-phase crystals is important to manipulating their useful properties. When the formation of an order parameter during a phase transition causes the crystal volume to be partitioned amongst the domains of the order parameter, the geometric interface between two or more such domains defines a type of topological defect. Because an order parameter is characterized by symmetry loss, it is most naturally described in terms of group-theoretical concepts. We demonstrate the use of group-theoretical constructs to classify domain-interface defects in single-phase crystals and to simulate their formation below a phase transition. [Preview Abstract] |
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A01.00044: Biaxial VSM Sensitivity and Crosstalk Measurement Dependence for Sxx(x,y,z), Sxy(x,y,z), and Sxz(x,y,z). Kolton Dieckow, Sara Beth Ragan, Chandan Howlader, Binod D.C., Wilhelmus Geerts A biaxial Vibrating Sample Magnetometer (VSM) vibrates a magnetic sample inside a controlled magnetic field and uses the induced voltage across the pickup coils to determine the sample's magnetic moment. From the hysteresis graph, magnetic moment versus field, one determines the sample's magnetic moment and coercivity. The angle dependence of those properties are often used to determine the magnetic anisotropy. The conventional method for aligning the samples in a VSM is to use a preset field value and then manually center the sample based on the x-sensitivity, Sxx(x,y,z). Here we explore other aligning approaches for a modified Mallinson pickup coil configuration, including using the cross talk Sxy(x,y,z) and Sxz(x,y,z) functions. Preliminary model calculations show that this approach is less susceptible to small misalignment errors in the z-direction and a more accurate positioning of the sample is possible. Few studies have been conducted to examine this relation and how it can affect VSM measurements of samples. Step motors to control the sample position were installed on a MicroSense EZ9 biaxial VSM. A variety of measurements of the Sensitivity and Crosstalk were performed with changing angle, position and field strength, and will be discussed. [Preview Abstract] |
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A01.00045: Angle resolved Raman Spectroscopy of RuCl3 thin layers Isaac Morales, Bowen Yang, Adam Tsen, Rui He Alpha-RuCl3 is a layered candidate material to host the Kitaev quantum spin liquid. However, the magnetic ground state of RuCl3 exhibits a zigzag antiferromagnetic (AFM) order, suggesting deviations from the pure Kitaev model. The in-plane zigzag AFM state corresponds to the orientation of the honeycomb lattice structure, whereas a method to easily determine the crystallographic axes for the exfoliated RuCl3 has not been established. We used angle resolved Raman spectroscopy to determine the in-plane crystal axes of exfoliated RuCl3. Samples were rotated in the xy-plane of the honeycomb lattice, and Raman spectra were taken in cross and parallel polarization configurations. By monitoring the Raman intensity from one of the Ag modes as a function of the rotational angle, we can determine the b-axis of the RuCl3 crystal. Our study provides a nondestructive and convenient method for determining the crystal orientation of RuCl3. [Preview Abstract] |
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A01.00046: Study on the Surfactant in the Dishwasher Detergent Using Chemical and Computational Analysis Sebin Lee, Sunhee Lee All the surfactants, the active agents in detergent consist of a hydrophobic group coupled to a hydrophilic group which has variations such as a negative or positive charge, no charge or a variable charge according to pH. In this research, computational methods employing quantum chemistry were used to model various surfactants in the linear alkyl groups and alkyl benzene sulphonates(ABS). The molecules were assessed for thermodynamic stability, reactivity and polarization. Certain number of Alkyl group based detergent and Alkyl benzene sulfate (ABS) molecules were tested for their thermodynamic stability which were measured through the optimized energy. Also the reactivity and conductivity were measured through the dipole moments to calculate the level of activity the molecule could have with other nearby molecules. Lastly, electrostatic potential maps were also used to visualize the polarization and assess the reactivity level of each molecule. Alkyl benzene sulfate(ABS) showed less activity and better stability. Alkyl group based detergent analogues showed better activity and less stability compared to the Alkyl benzene sulfate(ABS) due to their geometrical aspects. Depending on the degree of branching detergency performance and biodegradability were also discussed. [Preview Abstract] |
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A01.00047: Study on the Thermodynamic Stability of the Photovoltaic Cell Using Electro-mechanical and Physical Analysis Andrew Sung, So Min Lee, Richard 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. Numerous studies validating the fullerene’s potential to be used in the solar cell have led scientists to assess the safety of fullerene derivatives such as thermodynamic stability. This research uses computational method to study the thermodynamic stability of various fullerene derivatives and optical properties in the photoactive layer in organic solar cell. The research uses computational software to further display the optimized geometry energy levels and check electrical energy contour of solar cells. The Avogadro software is an open-source molecular editing program equipped with an auto-optimization feature, which determines the theoretical values of a certain structure’s atomic properties. Variables were quantified by their optimized energies, dipole moments, and electrostatic maps, respectively, after being modeled in the program. This software allows users to build virtually any nanoparticle and optimize its geometry according to various force field options. [Preview Abstract] |
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A01.00048: Surface plasmon drag effect in noble metal thin films Vivek Khichar, Suresh sharma, Douglas Zinn, Nader Hozhabri Nobel metals are useful to microelectronics because of their excellent electrical, optical and thermal properties. They are also important for surface plasmon resonance (SPR) sensors........$^{\mathrm{[1]}}$ The surface plasmon drag effect originates from light absorption due to excitation of surface plasmon polaritons on metal thin films......................$^{\mathrm{[2]}}$. Under the surface plasmon resonance condition, the component of the momentum of the incident $p-$polarized laser is transferred to the surface electrons in the film producing a drag voltage. Highly uniform noble metal films were deposited over Quartz substrates in \textit{class-100 clean room}, characterized by Atomic Force Microscopy, and used for SPR measurements. Simultaneously, drag voltages were also measured by using Keithley Nano Voltmeter. We present plasmon drag voltages for noble metal thin films as functions of the angle of incidence, polarization, and intensity of $\lambda \quad =$ 632 nm incident laser beam. .$^{\mathrm{1}}$S. C. Sharma, in \textit{Advances in Sensors: Reviews Book Series, Vol 5, IFSA Publishing, Barcelona, Spain 2018} $^{\mathrm{2}}$J. H. Strait et. al., Phys. Rev. Lett. \textbf{123} (5) (2019). [Preview Abstract] |
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A01.00049: A Rubric for Assessing Thinking Skills in Free-Response Exam Problems. Fatema Salmani, Beth Thacker We designed a rubric to assess free-response exam problems in order to compare thinking skills evidenced in exams in classes taught by different pedagogies. The rubric was designed based on Bloom's taxonomy. The rubric was then used to code exam problems. We analyzed exams from different sections of the algebra-based physics course taught the same semester by the same instructor with different pedagogies. One section was inquiry-based and the other was taught traditionally. We discuss the instrument, present results and present plans for future research. The inquiry-based students demonstrated all of the thinking skills coded more often than the traditional students. [Preview Abstract] |
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A01.00050: The NRAO NINE Program: Promoting Diversity, Inclusion, and Astronomy for Development Heather Harbin The National and International Nontraditional Exchange (NINE) program was implemented by the NRAO Office of Diversity and Inclusion with the intention to use radio astronomy as a tool for increasing involvement of underrepresented groups in the field. NINE Hubs, physical locations where students and professionals can receive training in radio astronomy, are currently being developed in both Honduras and Lubbock, Texas (Texas Tech University). During the summer of 2019, detailed plans for the new TTU Hub were drafted. Goals of the TTU NINE Hub include: increasing involvement in undergraduate astrophysics research; improving TTU astronomy curriculum with the introduction of a new 3000-level course; and contributing to a diverse STEM workforce. Working toward these goals, Python command-line tools were developed to be compatible with Raspberry Pi modules for use in the new course at TTU as well as in a potential summer workshop. TTU will continue to collaborate with other Hubs to accomplish NINE's objective of creating a network for knowledge exchange and broadening diversity in the radio astronomy community. [Preview Abstract] |
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A01.00051: Single Transducer Continuous Doppler Ultrasonic Sensors Sayantan Das, Javad R Gatabi Doppler ultrasonic sensors are widely employed for displacement and vibration measurements and imaging applications. Continuous Doppler ultrasonic measurement, compared to the pulsed Doppler technique, has the advantage of measurement-continuity and shorter minimum achievable range. Conventional continuous Doppler ultrasonic systems require the use of two transducers, one as a transmitter of the wave, and the other as a receiver. The proper alignment of continuous-wave ultrasonic transducers has always been a challenging process in precision measurements. On the other hand, continuous-wave ultrasonic systems have a significant temperature dependency. In this research we introduce a novel single transducer continuous Doppler ultrasonic measurement system. In this novel technique, the ultrasonic transducer works as a transmitter and a receiver at the same time. A reference series impedance and a compensation circuit has been designed to allow for distinguishing the transmitted signal from the received wave. Both theoretically and experimentally we prove that the displacement measurement by the fabricated sensor has less temperature dependence. [Preview Abstract] |
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A01.00052: Hydrodynamic Analog for Radioactivity Justin Edwards, Justin Chamberlain, Orrin Manning, Yasir Iqbal, Luis Grave de Peralta It has been shown that a drop of fluid can be made to bounce on a vertically oscillating bath of fluid. These droplets, known as ``walkers'', couple to the waves they generate. When a variation of depth in the fluid is introduced it creates a difference in potential; droplets crossing the barrier must do so on a transmitted exponentially decaying wave. We have created a system which spontaneously generates walker droplets to simulate particles leaving a potential well. In this system we use a forcing amplitude well above the Faraday instabilitythreshold to generate walker droplets autonomously. The droplets tunnel across a potential barrier to a damped region where the fluid is below the instability threshold. The formation of these droplets and their resulting kinetic energy is related to the amplitude and frequency of the driving oscillation. We studied the corral barrier's geometry and the driving frequency to understand the energy and formation of the droplets. The system could provide an analog to radioactivity in which particles spontaneously tunnel across a potential barrier, showing promise for future analysis. [Preview Abstract] |
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A01.00053: Neutrosophic Set as Generalization of Intuitioonistic Fuzzy Set, Picture Fuzzy Set and Spherical Fuzzy Set, and its Physical Applications Florentin Smarandache In this paper we prove that Neutrosophic Set is a generalization of the following: Intuitionistic Fuzzy Set, Picture Fuzzy Set (Inconsistent Intuitionistic Fuzzy Set), and Spherical Fuzzy Set. And we show several numerical examples. We also present some applications of Neutrosophic Set in physics. [Preview Abstract] |
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A01.00054: Study on the Properties of Biodegradable Polyesters Using Computational and Physical Simulations Yeonwoo Choi, Richard Kyung Polymers and plastics have been greatly expanded the many roles they play in the modern industrial economy. However the accumulation of polymeric micro-particles and polymer-based drug carriers in out body can be a significant health risk. A major disadvantage of many Polymers and plastics is their poor biodegradability, which limited their potential applicability in many areas including pharmaceutical uses. In this research, computational methods employing quantum chemistry were used to model various polyesters for their biodegradability and biocompatibility. To measure their effectiveness, the molecules were assessed for thermodynamic stability, reactivity, and polarization. To figure out the structural effect, aliphatic polyesters were first studied for their thermodynamic stabilities and biodegradability, which were measured through the optimized energies. Aliphatic polyesters have been widely used due to their biodegradability and biocompatibility. Also, aromatic polyesters which has excellent material properties but proved to be resistant to microbial attack, were studied for their thermodynamic stabilities and biodegradability. Many aliphatic polyesters turned out to be thermodynamically less stable so they are easily biodegradable. [Preview Abstract] |
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A01.00055: Study on the Effective Flavescens Molecules to Capture Fine Dust Using Chemical and Computational Analysis Jimin Baek, So Min Lee Various industrial pollutants, including heavy metals such as mercury and cadmium, have been major causes of health problems. The heavy metals are ubiquitous air pollutants which are increasing in the environment and they are responsible for many disease processes including carcinogenesis.These diseases are often attributed to poorly-detected air pollutants. Since there is a strong association between flavescens molecules and the effectiveness in fine dust removal, the effective flavescens molecules were modeled and analyzed using chemical and computational analysis. The molecules are also used in medical applications for their anti-inflammatory effects and effective activity in radical scavenging. The reactivity and conductivity were measured through the dipole moments to calculate the activity level the molecule could have with other nearby molecules. Also, electrostatic potential maps were utilized to visualize the polarization and assess the reactivity level of each molecule. The primary purpose of this research is to analyze the thermodynamical and stereochemical safety of several types of flavescens molecules and to find thermo-chemical properties of their derivatives that could be used as agents used in the air pollutants removal. [Preview Abstract] |
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A01.00056: On the accuracy and performance of the methods for computing the Integrated Autocorrelation of stochastic processes Weishu Deng, Amir Shahmoradi This study aims to test the accuracy and runtime efficiency of the existing methodologies for the computation of Integrated Autocorrelation (IAC) of stochastic time series data. These include the autoregression (AR), batch means (BM), and overlapping batch means (OBM). To perform an unbiased comparison of these methods' efficiency and accuracy, we generate several time series with theoretically-known integrated IAC. Then we test the performance and accuracy of each of methodologies by comparing the computed IAC with the theoretically-known values under a wide range of varying assumptions, for example, the length of the time series, the degree of the autoregressive processes, and the batch sizes in the BM and OBM methods. We also measure the computational complexities of each one of these methods by measuring the required time to compute IAC. Our observation is that the overlapping batch means method can generally provide the best tradeoff between accuracy and efficiency among all methods considered. [Preview Abstract] |
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