Bulletin of the American Physical Society
2022 Conferences for Undergraduate Women in Physics
Volume 67, Number 1
Friday–Sunday, January 21–23, 2022; Virtual
Session A01: Poster Session |
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A01.00001: Initial Development of a 3He Neutron Flux Detector for SuperCDMS Alya Sharbaugh, Anthony Villano One of the greatest challenges facing the dark matter community is the presence of a low-energy neutron-induced background. This background makes it difficult to distinguish the similar signals which could indicate dark matter detection. By developing a cryogenic liquid Helium-3 detector, we hope to reliably measure the neutron flux near the Super Cryogenic Dark Matter Search (SuperCDMS) cryostat and be able to model the background with greater efficiency. The scope of this poster includes preliminary research and theoretical modelling for the Helium-3 detector. [Preview Abstract] |
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A01.00002: Analyzing biochemical changes in Pork Tissue using Raman Spectroscopy Savannah West There is a need for a rapid, noncontact, observer method to analyze the degree of burn wounds. Raman Spectroscopy is a light-based technique that offers a promising solution for this problem. We use pork tissue as a substitute for human tissue before and after heating to various temperatures. We use Raman Spectroscopy to find biochemical changes to proteins and lipids caused by exposure to intense heat. These measurement will be used as a foundation for classifying burn wounds. [Preview Abstract] |
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A01.00003: Simulation of Magnetic Configurations in Mesoscale Permalloy Dots Abstract Elise Knutsen, Barry Costanzi, Kevin Clelland, Evan Arch, Logan Plasch The magnetic behavior of electrons can be clearly modeled at extreme length scales. However, at sizes in the hundreds of nanometers, the mesoscale, the behavior is difficult to predict due to the competition between the classical magnetostatic forces and the quantum exchange forces. Due to the large number of interacting spins, these systems cannot be easily modeled analytically, necessitating a numeric technique. We use Mumax3 micromagnetic simulation to determine the magnetic states of square permalloy (Ni$_{80}$Fe$_{20})$ dots that are 100's of nm on a side. Understanding magnetic materials at this scale is critical for the future development of spintronic devices and to understanding the fundamental physics of middle-scale systems which are neither strictly classical nor quantum. [Preview Abstract] |
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A01.00004: Analysis of the cathodoluminescence of zircon crystals and photometry of planetary nebulae using Python Chloe Jones, Kristin Rabosky, Stacy Palen, Elizabeth Balgord The field of spectroscopy can help unlock many mysteries about the composition and history of a given substance. Cathodoluminescence, a branch of spectroscopy correlating specific wavelengths to specific impurities, is a valuable tool to both physicists and geoscientists, allowing for the analysis of individual zirconium crystal grains a few micrometers in size. Photometric techniques help astronomers analyze the light received from macroscopic objects such as planetary nebulae stretching trillions of kilometers across many lightyears away. Both techniques use imaging through different colored filters to obtain spectroscopic data from the objects of interest. Light intensity data embedded in these images can be extracted by using image analysis software and then can be correlated to the emission spectra, and therefore the composition, of the object in question. Python is an excellent tool for creating a consistent and efficient method for image and graphical analysis. In this project, we identified the characteristics that make spectroscopy applicable across fields, described the coding process for analyzing data, and applied the idea of elemental ``fingerprints'' to gather information regarding sample composition. [Preview Abstract] |
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A01.00005: Precise Control of Qubit Frequencies in a Superconducting Quantum Processor Cora Barrett Quantum computers can solve certain problems that are deemed impossible on classical machines. The building block of our superconducting quantum processors is a tunable transmon qubit (quantum bit), which is composed of a capacitor and two Josephson junctions in a SQUID (superconducting quantum interference device) loop. To perform calculations, we need to be able to control the qubits with a high degree of precision. One critical property of a tunable transmon qubit is its transition frequency, which is controlled by changing the magnetic flux through its SQUID loop via a flux line. We need to compensate for the cross-talk from the flux lines targeting other qubits, so that we can control each qubit individually. Due to the number of measurements required, calibrating the flux cross-talk for the entire processor is a time-consuming process (\textasciitilde 18 hours for a 3x3 qubit array). We use statistical analysis to determine the minimum number of measurements needed to control the qubit frequencies with less than 0.01{\%} error. We use the results of these simulations to design a faster and more accurate calibration protocol. Decreasing the calibration time will bring larger quantum processor sizes within experimental reach. [Preview Abstract] |
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A01.00006: Realizing transfer-free van der Waals heterostructures Annie Cheng, Chengyu Wen, A. T. Charlie Johnson After the discovery of graphene in the early 21$^{st}$ century, there has been much focus on two-dimensional layered materials, also termed van der Waals heterostructures. Since graphene, much effort has been dedicated to exploring hexagonal boron nitride (hBN) and transition metal dichalcogenides (TMDs) such as MoS2, WS2, and WSe2. TMD monolayers have been the subject of much interest due to their fascinating electronic and optical properties. However, the sensitivity of TMDs makes them susceptible to contamination and degradation, with charge impurities at the TMD interface obscuring and degrading electronic and optical performance. Dielectric encapsulation of TMDs with hBN has therefore been suggested as a way of protecting TMDs and improving device performance, since hBN has an atomically flat surface with no dangling bonds, and it has been shown to improve carrier mobility and transconductance in devices. However, the multiple transfers of hBN and TMDs required for dielectric encapsulation often result in contaminants or dopants, adversely affecting the sample. We herein investigate the possible ways of preparing an MoS$_{2}$-hBN heterostructure through chemical vapor deposition. It was found that, using a precursor solution of ammonium molybdate tetrahydrate and sodium chloride, multilayer MoS$_{2}$ was able to grow on top of a monolayer hBN surface with the hBN still intact. This demonstrates the promise of large-scale synthesis of MoS$_{2}$-hBN heterostructures, which would be highly advantageous in future device applications. [Preview Abstract] |
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A01.00007: Scanning Photocurrent {\&} Spectroscopic Mapping via Automation Anna Paulsen At the nanoscale, quantum mechanical effects take hold and alter material's optical and electronic properties in sometimes unexpected ways. Advances in nanotechnology (e.g. transistors or memory) greatly depend on understanding how to control these phenomena changes and ultimately be able to reproduce them. We analyze these characteristics using a range of techniques that leverage the optical properties of different types of light in order to capture high resolution images, optical spectra, and various other measurements of unknown samples. In order to achieve this, precision of sample movement is critical for reproducible measurements, precision focusing, and mapping of sample properties. [Preview Abstract] |
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A01.00008: The Electronic and Lattice Vibrational Properties of various ground states of Ge-doped FeGa3. Tenzin Sherpa, Prithivi Rana, Aashish Poudel, Rodica Martin, Ihor Sydoryk, Petrovic Cedomir, Weijun Ren, Catalin Martin FeGa$_{3}$ has been investigated for its large thermopower effect at low temperatures, and the effects of electron correlations such as insulator to metal crossover, non-Fermi liquid behavior, and ferromagnetism. Furthermore, a ground state crossover from an insulator to paramagnetic and then to a ferromagnetic metal has been observed in Ge-doped FeGa$_{3}$. The large thermopower effect has been discussed to be a result of strong electron correlations or of the electron-phonon drag effect. In this study, we present the optical reflectance measurements for single crystals of FeGa$_{3-x}$Ge$_{x}$, for different values of x. The measurements were taken at varying temperatures from 300K to 5K, over a frequency range of 40 cm$^{-1}$ to 50000 cm$^{-1}$. We use Kramers-Kronig transformation to obtain various optical functions and compare the electronic and lattice vibrational properties of different ground states formed by Ge-substitution at Ga sites in FeGa$_{3}$. We also discuss that our observations show that the electron-phonon drag effect may have a greater contribution in the large thermopower effect. [Preview Abstract] |
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A01.00009: First-Principles Study of Single Molecule Magnet Mn$_{12}$ on Graphene with Defects Morgan Hale, DaVonne Henry, Paola Barbara, Amy Y. Liu Transport through graphene devices can be used to probe the electronic and magnetic properties of molecules deposited on the graphene surface. Previous experimental work on the single molecule magnet (SMM) Mn$_{12}$ deposited on graphene showed that the substrate-SMM charge transfer and the carrier mobility of the graphene are sensitive to the choice of ligand [1], consistent with trends found in density functional theory (DFT) studies [2, 3]. Motivated by recent experiments [4] that showed charge transfer inconsistent with prior reports, we consider whether defects in graphene could account for the discrepancy. In this work, DFT calculations were carried out to characterize [Mn$_{12}$O$_{12}$(COO$R)_{16}$](H$_{2}$O)$_{4}$ deposited on graphene with a vacancy defect. Results of optimized structures, energetics, magnet properties, and charge transfer will be presented for ligands~R $=$ -H, -CH$_{3}$.~ [1] X. Zhu, A. Hale, G. Christou, A. F. Hebbard, J. Appl. Phys. 127, 064303 (2020). [2] X.-G. Li, J. N. Fry, H.-P. Cheng, Phys. Rev. B 90, 125447 (2014). [3] A. Brooks., T. Jiang, S. Liu, D. Le, T. S. Rahman, H.-P. Cheng, and X.-G. Zhang, Phys. Rev. B 103, 245423 (2021). [4] D. Henry, L. St. Marie, A. Alqahtani, Y. Liu, D. K. Gaskill, R. L. Myers-Ward. I. Nemac, P. Neugeberger, P. Barbara, unpublished. [Preview Abstract] |
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A01.00010: Influence of temperament on mathematical properties of a musical scale Julia Oseka This paper focuses on investigating the mathematical properties of a musical scale tuned in Pythagorean tuning and 12-TET temperament. The experimental analysis was conducted using measurement of perfect fifths: G3(196Hz)-D4(293Hz), D4(293Hz)-A4(440Hz), and A4(440Hz)-E5(657Hz) played on piano (tuned in 12-TET) and violin (tuned in Pythagorean tuning). The recordings were then studied using the Fast Fourier Transform spectral analysis method, based on the, previously derived, Fourier Series and Fourier Transform. The spectral representation of a complex sound uses the property of Fourier Transform, in which the value of a transform F(n) provides the magnitude of a frequency n and its phase. If the criteria for f(x), being a real-valued function are met, then the transform function F(n) is the complex conjugate of F(-n). In such case, the amplitude of such function can be described as \textbar F(n)\textbar . The program uses this property to determine the energy density in the input sound. This method of investigation is simple and has many limitations, however, the differences in the spectra of each of the composite fifths played in two different temperaments showed significant difference in scale's mathematical and physical properties. [Preview Abstract] |
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A01.00011: Study of V$_{Ga}^{-2}$ in $\beta $-Ga$_{2}$O$_{3}$ through EPR Claudia Nardone, Mary Ellen Zvanut, Suman Bhandari Gallium vacancies (V$_{Ga})$ are thought to be common defects found in Ga$_{2}$O$_{3}$. It is important to understand the interaction among defects because charge transfer can cause unwanted effects to happen when Ga$_{2}$O$_{3\, }$is used in high powered devices. Many in the past have attributed problems with Ga$_{2}$O$_{3\, }$to gallium vacancies without being able to observe the vacancy directly. In our work, two neutron-irradiated Ga$_{2}$O$_{3\, }$samples, one as-grown and one Fe-doped, were studied using photo-induced electron paramagnetic resonance (photo EPR), so that charge transfer between various defects could be monitored. In particular, we were able to observe V$_{Ga}^{-2}$ as well as Fe$^{+3}$ in both samples so that potential charge transfer could be seen. The concentrations of Fe$^{+3}$ and V$_{Ga}^{-2}$ were studied under the illumination of various photon energies. The concentration of Fe$^{+3}$ in both samples decreased, which was consistent with the results obtained with non-irradiated samples where V$_{Ga}^{-2}$ was not seen. Significantly, the concentration of V$_{Ga}^{-2}$ in both neutron-irradiated samples did not change. This suggests that the V$_{Ga}^{-2}$ defects are not responsible for the change in the concentration of Fe$^{+3}$ as suggested by others. [Preview Abstract] |
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A01.00012: Simulating Transport of Magnetic Microparticles on Disk Array Traps Eliza Howard, Gregory Vieira, Dung Hoang, Ryan Simms, David Raymond, Edward Cullom The manipulation of superparamagnetic microparticles, or beads, by applying controlled, tunable forces without direct external contact has applications in sorting and purifying heterogeneous liquid samples, useful for biology and chemistry, and can be used as components for lab-on-chip devices. This can be accomplished by using an array of magnetic traps. In our set-up, the beads are moved by applying and varying external magnetic fields to create and rotate magnetic traps around the periphery of permalloy disks. We created a computer simulation using Python which replicates bead motion and therefore helps provide a better understanding of the phenomena we observe, as well as the magnetic properties of the disks and beads. Using short-range motion, the repulsion of a bead from one disk to the next, we fit the simulation's predictions to experimental results and determined parameters for bead magnetic susceptibility and the strength of the magnetic fields from the disks. The simulation successfully replicates and predicts phenomena such as the path a bead takes as it travels, limitations on bead speed, and the correlation between various parameters, such as bead radius or external magnetic field, and bead motion. [Preview Abstract] |
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A01.00013: Percolation Threshold of Sputtered Thin Films Jordyn Redmond Percolation threshold for a material is the point at which an insulating material transitions to a conductive material, usually within several to tens of nanometers. Results from this research could be helpful in optimizing electronic devices, as this threshold marks the physical limitation for how thin electronic components made from these materials can be while still being conductive. After depositing various thin films of both aluminum and molybdenum via the Weber State University sputtering system, we measured the materials' resistance to determine the threshold thickness. I determined the percolation threshold for aluminum lies in the range between 5 and 7.5 nanometers, while molybdenum's percolation threshold lies in the range between 7.5 and 10 nanometers. During testing it was also determined that exposure to ambient air significantly skews the results due to native oxide growth on the films, so problem solving methods are discussed. [Preview Abstract] |
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A01.00014: Similarity Spectra Analysis of Jet Noise from a High-Performance Military Aircraft Kristi Epps, Kent Gee The noise footprint from high-performance jet aircraft impacts people, from military personnel to communities. However, the noise source mechanisms and radiation properties associated with high-thrust jet engines are not well understood. One method for analyzing these properties is to compare their spectra to models for different jet noise phenomena. This research presents comparisons between measured near-field spectra from a military jet engine with empirical similarity spectra for fine-scale mixing noise, large-scale mixing noise, and broadband shock-associated noise. The similarity spectra analysis yields spatial trends for the different spectral models, helping determine the relative importance of each type of noise radiation as a function of location. This method can be used to gain insights into noise changes for different engine conditions and to compare with other aircraft and jets of other scales and conditions. [Preview Abstract] |
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A01.00015: Permittivity Measurements of Highly-Insulating ~Materials Heather Allen, Jordan Lee, JR Dennison Permittivity of a dielectric material characterizes how it responds to external, time-varying electric fields and the associated energy loss. This electrical property of the material has important applications with optics, electrical transport, and charge accumulation and dissipation. This experiment focused on permittivity values of polyetheretherketone (PEEK) samples to determine if exposure to high ionizing radiation dose has any effect. Four samples were tested, two unirradiated PEEK samples (one unplated and one with an Au electrode on one side) and two neat PEEK samples previously irradiated with high energy electrons. A standard commercial impedance analyzer and material test fixture were used to take the actual measurements within the range of 10kHz to 10MHz. To gauge the reproducibility and validity of the experimental setup and process, at least two sets of measurements were acquired for each sample, done by different investigators, removing the sample from the testing fixture each time. Comparison of both the real and imaginary permittivity of unirradiated and irradiated samples with variations between the four samples of less than 1 percent determined that there were no statistically significant effects of total ionizing dose from incident electrons. [Preview Abstract] |
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A01.00016: Advancement in Infrared Optics Through the Exploration of Solution Derived Arsenic Selenide (As2Se3) Thin Films Annabella Orsini There are great opportunities for advancement in the realm of infrared optics through chalcogenide glasses (ChGs). There are a vast number of applications these glasses are involved in. For instance, ChGs are vital in search and rescue operations, firefighting efforts, medical imaging, and even satellites. At the moment, there are some issues with the stability and cost of ChGs. Bulk ChGs can be brittle and fragile, so we will explore the significance of using thin films instead. Our research takes a multidisciplinary approach to ChGs involving physics, chemistry, optics, and materials science. Our focus will be creating thin films that will be more applicable and effective than previously used bulk versions. To be specific, we will use Arsenic selenide (As2Se3) and ethanolamine to create these thin films through both spin-coating and dip-coating processes. The films will then be tested on their stability and transmission capabilities into the infrared. Our use of As2Se3 is a process that has not been as deeply explored in comparison to other materials. Therefore, this research will also lay out a framework for a laboratory process when working with the Arsenic selenide material. [Preview Abstract] |
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A01.00017: COMSOL Simulations of molecular sieve based Gas Sensor Kendra Rivers, Kevin Daniels The gas sensing mechanisms of robust and selective solid state gas sensor, composed of electrodeposited, 2D layered manganese dioxide (MnO2) synthesized on quasi-freestanding epitaxial graphene (EG) on silicon (SiC) heterostructure is explored. The large interlayer spacing of MnO2 of 0.74 nm, can act as a molecular sieve, increasing the selectivity of the heterostructure sensor by rejecting larger molecules. The interlayer can also be tuned though intercalation of cations, which can increase the permeance of target gases. The permeance of gases, with varying kinetic diameters through these interlayers is not well understood. Using the Particle Tracing for Fluid Flow physics module in COMSOL~ shows the interaction of molecules within the interlayer spacing being investigated, observing the molecular sieving capabilities of the heterostructure to validate its potential as a selective gas sensor. Our results will show the 0.364nm size particles (Nitrogen) flowing towards the MnO2 layers, from here we can either see the particles are rejected or flowing through the layers which in both scenarios increases the selectivity.~ Additionally, we designed a built-in potential model to show electrical interaction within the MnO2-EG heterostructure with gold contacts. The simulation from the built-in model gives results of the electric potential, electron concentration and hole concentration, which shows the flow of the current with the charge potential. The results we gain from the simulation models are used to compare with physical experimental results of the gas sensor.~ [Preview Abstract] |
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A01.00018: Comparing Theoretical Models of Speed of Sound Attenuation in Corrugated Tubes Alexandra Lee The group velocity of sound waves traveling through a periodically corrugated tube is lowered by an amount which depends on the physical parameters of the corrugations. There are two models which relate the physical parameters of the corrugations to the reduction in the group velocity- one well-documented based on acoustical engineering and the other with foundations similar to Bloch Theory. In the latter case, the 1-dimensional wave equation is used to find frequencies that would be resonant in the periodically corrugated tubes. Using the linear relationship between frequencies and sound velocity, we could then find the effective velocity of sound throughout the tube. This project analyzes the effect of modifications on the physical parameters of the corrugations based on these models. Numerical calculations performed in Mathematica are investigated to find corrugation types which show the greatest discrepancies between the two models. Theoretical predictions can be compared to experimental results from 3D printed tubes specially designed to test the veracity of these models. [Preview Abstract] |
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A01.00019: Replace this text with your abstract title. Jiawei Liang Replace this text with your abstract body. [Preview Abstract] |
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A01.00020: Simulating Amorphous Silicon Pillars on a Silica Substrate Katie Barajas, Giovanni Sartorello A metasurface composed of amorphous silicon pillars shows promise for use in biophysical experiments. The focus of this study is to simulate a subunit of an amorphous silicon metasurface under various environmental conditions. Transmittance and field enhancement are simulated in water and air to corroborate experimental results. [Preview Abstract] |
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A01.00021: Two-Dimensional Sliding of Ni-Doped MoS2 Elsa Vazquez, Enrique Guerrero, David A. Strubbe MoS$_2$ is a layered transition-metal dichalcogenide shown to have many functional properties, but an original application is lubrication, especially for outer space. Ni is a dopant known to increase its lubricity. In this computational study, we slide in the x and y directions the bi-layers of Ni-doped MoS$_2$ and use density-functional theory to find the sliding potential energy surface (PES) in a $2 \times 2$ supercell. The structure is doped by swapping a Mo or S atom and by intercalation where we insert Ni between the layers leading to octahedral or tetrahedral structures. For the two substitution sites, there are overall differences in magnitudes. The tetrahedral site has the largest amplitude with steep paths between saddle points. The octahedral site has smoother transitions between stable and unstable sites. Compared to the PES of the pristine cell there is a resemblance for the substituted sites, but not for the intercalated sites. The Mo-substituted supercell roughly shares with pristine the positions corresponding to the stable, metastable, and unstable sites. Notably, the S-substituted case seems to switch the positions of the stable and meta-stable sites. Our findings on the sliding potential of Ni-doped MoS$_2$ provide insights into its mechanisms for lubrication. [Preview Abstract] |
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A01.00022: A Model Quantum Spin Ice: Phase Diagram Construction for Quantum Spin Ice Under the Transverse Ising Model with Exact Diagonalization and Numerical Linked Cluster Methods Jessica Jiang, Yutan Zhang, Rajiv Singh In this poster, we present calculations of properties at $T=0$ of the quantum spin ice checkerboard lattice under the Transverse Ising model using Exact Diagonalization (ED) Numerical-Linked Cluster (NLC) methods up to order six. We use Exact Diagonalization methods to calculate properties for the finite system ($4\times 4$ lattice) and a combination of ED and NLC methods to approximate them for an infinite quantum spin ice lattice. Our results reproduce the expected behavior of the lattice for the magnetization $M$, the entanglement entropy $S_E$, the N\'eel state order parameter $S_{\pi, \pi}$, the susceptibility $\chi_F$, and the fidelity susceptibility $\chi_F$ at different values of the applied magnetic field, $h$, and the ratio of the far and near neighbors bond strength, $J_2/J_1$. We additionally calculate the system's self-consistent x-direction magnetization to estimate the critical field value $h_c$ at which a second order phase transition occurs. Ongoing work will extend this analysis and construct a complete phase diagram for the system using these methods. [Preview Abstract] |
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A01.00023: Phase Diagram of Valence Transition below 14T and above 2K for Ce$_{1-x}$Pr$_{x}$Os$_{4}$Sb$_{12\, }$, x$=$0.1 and 0.2 Leticia Ramos, Xingyu Zhao, Zachary Carrender, Tatsuya Yanagisawa, M. Brian Maple, Pei-Chun Ho Filled skutterudite compounds are described by the chemical formula: LnT$_{4}$Pn$_{12}$ where Ln is a rare-earth metal, T is a transition metal, and Pn is a pnictogen. CeOs$_{4}$Sb$_{12}$ is a Kondo insulator that exhibits antiferromagnetism due to spin-density wave formation below 1 K. Based on the band-structure calculation, CeOs$_{4}$Sb$_{12}$ is suggested to be a candidate for topological insulators, which may have a hole Fermi surface and an electron Fermi surface coexisting at low temperatures. Through our previous studies of CeOs$_{4}$Sb$_{12}$, we found that a valence transition occurs in this compound, and we have established an intriguing temperature, $T$-, magnetic field, $H$, phase diagram in its normal state. Nevertheless, the neighboring isostructural compound PrOs$_{4}$Sb$_{12}$ is a heavy-fermion superconductor with a transition temperature at 1.85 K. When Pr substitutes Ce in CeOs$_{4}$Sb$_{12}$, a hole-doping is introduced. We plan to study the series of Ce$_{1-x}$Pr$_{x}$Os$_{4}$Sb$_{12}$ to investigate the influence of hole-doping to the valence transition. In this report, we will show the preliminary results of normal state resistivity of two concentrations: x$=$0.1 and x$=$0.2 from 300 K to 2 K in magnetic fields ranging from 0 to 14 Tesla as well as the $T-H$ phase diagram updated with the doped samples' resistance data. [Preview Abstract] |
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A01.00024: Magnetic Anisotropy of $CsCoCl_{3}$ at High Magnetic Fields Eleni Kyriazi, Scott Crooker, Fedor Balakirev, Johanna Palmstrom, John Singleton, Laurel Winter, Arkady Shekhter, Ross McDonald $CsCoCl_{3}$ is a quasi one-dimensional Ising antiferromagnet, forming a hexagonal $P6_{3}/mmc$ structure [1], [2]. One peculiar aspect of this correlated spin system is the fine balance between the Coulomb energy, responsible for the observed large spin at high magnetic fields, and the crystal-field energy in the orthorhombic Cl environment, responsible for the spin-1/2 at low magnetic fields [1]. Related to that energy scale competition is the anomalously large magnetic anisotropy in this material with nominal spin-orbit interaction on the 3d transition-metal $Co^{2+}$ ion. Here I will present comprehensive angular dependence studies of the magnetic anisotropy of $CsCoCl_{3}$ from measurements of the magnetotropic susceptibility in fields up to 15 Tesla and temperatures between 1.4 and 30 Kelvin. The nature of the strong magnetic anisotropy in this weak-spin-orbit system can potentially be resolved by analysis of the magnetization at high fields. I will discuss the angular dependence of the magnetic anisotropy in this system and its implication for the nature of the local spin and exchange Hamiltonian in $CsCoCl_{3}$. [1] Amaya, et al., Journal of the Physical Society of Japan 59 5, 1810-1816, (1990) [2] Soling, Acta Chemica Scandinavica 22, 2793-2802, (1968) [Preview Abstract] |
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A01.00025: Keeping Our Sheet Together: Dynamics and Fragmentation in Yield-Stress Fluid Sheets Carly Galvin, Brendan Blackwell, Michelle Driscoll The two-dimensional geometry of an expanding fluid sheet presents a unique opportunity to explore material instabilities. The behavior of these sheets and the ways in which they fragment have been examined for several centuries, but the vast majority of this research has centered around Newtonian fluids. We are working toward an analogous understanding of complex fluid sheets, focusing specifically on yield-stress fluids. In our experiments, we generate the sheets via the collision of two liquid jets and film their dynamics using high-speed photography; the behavior of the sheet is set by the rheology of the fluid and the velocity of the impinging jets. Our findings indicate that quickly-expanding sheets (created by faster jets) are less stable than slowly flowing sheets. We will show that fragmentation can be categorized into different regimes based on jet velocity, jet diameter, and concentration of polymer. Furthermore, we use a suite of different fluids to determine which fluid parameters (such as yield stress, infinite-shear viscosity, surface tension, and elasticity) control the stability of the sheet. [Preview Abstract] |
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A01.00026: Automation of Spectroscopic Characterization of Quantum Defects Jenna Tempkin, Anna Paulsen, Annemarie Exarhos A crystal defect is any imperfection within the repetitive and periodic structure of a crystal. There are many different types of defects, but we focus specifically on quantum defects, which are point defects that consist of one or a few atoms. In certain types of wide-bandgap semiconducting crystals, these defects emit fluorescence. Some of these defects fluoresce at visible wavelengths, so we can easily characterize and analyze the fluorescence using an optical spectrometer. These crystal defects can have important applications in quantum technology, including use as qubits for quantum computers, and in quantum sensing. This research aims to create a mostly automated and reproducible confocal fluorescence microscope to optically characterize these quantum defects in new materials. [Preview Abstract] |
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A01.00027: Sputtered Growth and Analysis of Thin Film Bismuth Selenide Topological Insulators Margaret Brown, Said Elhamri, Joseph Corbett, Amber Reed Thin films of bismuth selenide, a well-known topological insulator, were grown via direct-current magnetron sputtering. The films were studied using X-ray diffraction, atomic force microscopy, scanning electron microscopy, and scanning tunneling microscopy to analyze how growth conditions impact the resulting surface morphology. Various growth recipes were explored to investigate the transition from atomically smooth films to much more faceted structures, and to provide more insight on fine tuning the surface morphology and the initial layering of this topological insulator. [Preview Abstract] |
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A01.00028: Integrating Machine Learning and Physics-based Heuristics for Solitonic Excitation Classification in Bose-Einstein Condensates Sophia Koh, Shangjie Guo, Amilson Fritsch, Ian Spielman, Justyna Zwolak Bose-Einstein condensates (BECs) are ultracold collections of atoms which exhibit macroscopic quantum effects. In BECs, we can create solitons--robust, localized waves which appear in images as a local decrease in BEC density. With a dataset of labeled BEC images, we trained a machine learning (ML) model to locate solitons. Though solitonic excitations such as solitons and solitonic vortices represent distinct physical states, the ML system identified all as solitons. We built a quality estimator to measure confidence in the presence of a soliton by summing the images vertically and using a five-parameter fit to a function describing an idealized soliton profile. While the quality estimator is effective with vertically-consistent solitons, it has limited applicability to vertically-varied distributions such as solitonic vortices. With the goal to determine the type of solitonic excitation, we estimated the quality of separate segments of each image and analyzed the differences between fit parameters to distinguish solitonic excitations. Using ML to locate solitonic excitations and the improved quality estimator to distinguish types of solitonic excitations, the integration of ML and physics-based heuristics improved our solitonic excitation classification and detection pipeline. [Preview Abstract] |
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A01.00029: A Comparison Between Tree-Based and Deep Learning Algorithms in the Identification of Thin Materials Laura Zichi, Tianci Liu First isolated in 2004, graphene monolayer sheets display unique properties of promising technological potential and the cutting edge methodologies used for their fabrication have expanded to create two-dimensional (2D) analogues from other bulk materials. However, current techniques for locating exfoliated materials have low-throughput and often rely on inefficient manual identification. Integration of high-performance machine-learning and optical microscopy can accelerate flake identification. Although Convolutional Neural Network (CNN) based deep learning algorithms significantly advance object recognition, their high computational complexities, large dataset requirements and the lack of comprehensive theoretical understandings of their mechanisms limits their accessibilities. We propose an alternative approach, tree-based methods, with features that mimic color contrast, and compare them to ResNet, a CNN model, for identification of exfoliated $\text{MoSe}_{2}$ under different optical settings. We show with Gradient-weighted Class Activation Mapping, a standard visualization technique for CNNs, that despite achieving high accuracies CNNs usually failed to identify flakes in many images which jeopardizes their generalizability and reliability for 2D material modeling. [Preview Abstract] |
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A01.00030: Strain Mapping of Quantum dot Superlattices using 4D-STEM Sara Irvine, Michelle Smeaton, Lena Kourkoutis Quantum dot super-lattices that have epitaxial connections are a developing system of quantum materials. Super-lattices provided another knob in which to tune electronic properties. The electronic properties are still limited in part due to defects in the connections, which limit charge delocalization in the super-lattice. In this work, we used 4D-Scanning Transmission Electron Microscopy(STEM) and the Cesptrum transform to map the local strain in a super-lattice of PbSe quantum dots. We observed strain defects in the necks of a super-lattice of PbSe quantum dots. [Preview Abstract] |
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A01.00031: Simulating Pressure-Driven Solid--Solid Phase Transformations Across Crystal Structure Types Hongjin Du, Hillary Pan, Julia Dshemuchadse Materials' properties can vary widely based on the pressure at which they are formed and the crystal structure that they adopt---an example being the graphite and diamond allotropes of carbon. Many materials undergo structural transitions if they are put in a pressurized environment. Here, we investigate the high-pressure behavior of sixteen known, self-assembled structures under isotropic compression. We model these systems with molecular dynamics simulations of particles that interact via simple pair potentials. Particles, which spontaneously self-assemble into these different crystal structures, are initialized and then pressurized through a successively decreasing simulation box size. We observe pressure-driven solid--solid phase transitions across structure types, as well as a variety of other transformation behaviors as a function of pressure. We compare our findings with the pressure-dependent structural behavior that is known from atomic systems. Our work expands current knowledge on relationships between structure and pressure, and paves the road toward switchable materials. [Preview Abstract] |
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A01.00032: Chemical Shift Detection with Energy Dispersive Spectroscopy (EDS) Rebekah Jin, Yarin Heffes, Allen Wang, Jared Lodico, B.C. Regan, Matthew Mecklenburg Chemical bonds generally change the binding energies of an atom's core-state electrons in an effect called chemical shift. When aluminum is oxidized, its L$_{2,3}$ and K-edges shift up by 2-4 eV from the 73 eV characteristic of the pure metal. Here, we seek to develop a technique for measuring chemical shifts based on energy dispersive spectroscopy (EDS) instead of the commonly employed electron energy loss spectroscopy (EELS). When measured by the full width at half-maximum (FWHM) of x-ray peaks, EDS has an energy resolution of order 100 eV, but curve fitting can locate peaks to much better precision. We perform EDS mapping on a spectrum image sample of aluminum nanowire contacts with a partial aluminum oxide coating. For each EDS spectrum in the datacube, we fit the aluminum K-alpha peak with a Gaussian, locating the peak with a precision of 1 eV or better. We generate a map showing the x-ray energy at each real-space position, producing a line profile from a vertical (spatial) axis average which indicates an aluminum-aluminum oxide shift of around 10 eV, larger than the 2 eV expected based on EELS results from the literature. Though still ongoing, our work so far implies detectability; we are now continuing to investigate the source of the shift discrepancy. [Preview Abstract] |
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A01.00033: Determining the Origin of Insulating States in TaS2 with Atomic Adsorbates Lihy Buchbinder Mott insulators are materials that should behave like conductors according to electronic band theory, but act as insulators due to strong electron-electron interactions in the material. These complex interactions, combined with spin-orbit coupling, make them incredibly complicated to describe theoretically. Yet we need such fundamental understanding to utilize these quantum materials in logic devices and other applications. For my project, I tested a direct experimental way, reported by Lee et al. (2021), to distinguish a Mott insulator from a trivial insulator using atomic adsorbates. I studied the origin of the insulating state in tantalum disulfide (TaS2) by depositing gold atoms on the surface and performing scanning tunneling microscopy (STM) and spectroscopy. Based on the chemical response of the surrounding surface to the adsorbates, I determine the type of insulating state. Future work will explore the effect of stacking order in the crystal on the type of insulating state observed. [1] Wang, Y.D., Yao, W.L., Xin, Z.M., Han, T.T., Wang, Z.G., Chen, L., Cai, C., Li, Y., & Zhang, Y. (2020). Band insulator to Mott insulator transition in 1T-TaS2. Nature Communications, 11. [2] Lee, J., Jin, K., & Yeom, H.W. (2021). Distinguishing a Mott Insulator from a Trivial Insulator with Atomic Adsorbates. Physical review letters, 126 19, 196405. [Preview Abstract] |
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A01.00034: 3D Dynamic Simulations of Sea Fan Structures Ariana Vlad, Asja Radja, Anna Lappala Sea fans are a variety of corals structured in a flat fanlike pattern of numerous cylindrical polyps. Their morphology has been previously studied through 2D images and digitized data points depicting the structures have been obtained. The project employs polymer physics and molecular simulations to study samples of tree-like and network structures and analyze differences in their dynamics. The sea fans’ motion was initially simulated with the Large-scale Atomic/Molecular Massively Parallel Simulator Molecular Dynamics software by connecting the data points through harmonic bonds and modulating the flexibility/bending stiffness through an angle potential between three particles. Next, hydrodynamics was integrated using Smooth Particle Hydrodynamics and the Constant Energy Dissipative Particle Dynamics. Preliminary analysis of the output through particle displacements computations suggests that tree structures tend to be more dynamic than networks and that the greatest displacements correspond to outer particles, a result consistent with experimental findings. Further analysis of all available structures is necessary to conclusively find the correlation between the morphology of sea fans and their environment. [Preview Abstract] |
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A01.00035: Retrieving masked signal through tracking and wavefront shaping Kaitlin Jennings, Nazifa Rumman, Tianhong Wang, Pascal Bassene, Finn Buldt, Moussa N'Gom We present a novel wavefront shaping approach that allows for the tracking and localization of hidden objects within or behind a scattering medium. The method combines traditional feedback based wavefront shaping with a switch function using two different signals. Using two detectors, one monitors the speckle signature from the scattering sample while the other tracks the fully hidden signal (e.g. fluorescent beads). The algorithm is established to optimize the incident field to maximize light transmission into a random point. The dynamic optimization of the field will induce instantaneous changed in both signals being monitored. The modulation process redirects the input signal, which in turn allows the location of the hidden objects. With the increase in the targets distinction the algorithm switches to use this signal as the feedback. We provide experimental demonstrations as a proof of concept of our approach. Potential applications of our method include extracting information from biological samples and developing noninvasive diagnosis methods. [Preview Abstract] |
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A01.00036: Parametric Imaging of White Matter and Grey Matter of Fixed Sheep Brain Claudia Chambliss, Will Newman, Cecille Labuda, Brent Hoffmeister The frequency slope of attenuation (FSA) in sheep brain specimens was measured at multiple locations to generate parametric images (PIs) that characterize its spatial distribution. The goal was to determine whether grey and white matter can be differentiated in a single specimen by measuring the FSA in regions containing only grey matter and only white matter. Tissue specimens were 1-cm-thick slices of preserved sheep brain prepared from the transverse cardinal plane. Ultrasonic measurements were performed using broadband transducers with center frequencies of 3.5, 5.0, 7.5 and 10 MHz. The transducers were mechanically scanned to acquire signals over entire specimens. The FSA was calculated at each scan location and these values were imported into image processing software to generate the PIs. By comparing the PIs to photographs of the specimens, regions of interest (ROIs) containing only white matter and only grey matter were selected in the PIs. The average FSA and the standard deviation in each ROI was measured. Measured values in white matter for the mean and standard deviation over all samples and frequencies of the FSA ranged from 0.634 - 1.459 dB/cm\textbullet MHz and 0.019 - 0.169 dB/cm\textbullet MHz respectively. For grey matter FSA ranged from 0.429 - 0.955 dB/cm\textbullet MHz with standard deviation ranging from 0.016 - 0.08 dB/cm\textbullet MHz. These results indicate that the spatial mean of the FSA is higher for white matter than for grey matter and thus a high probability of differentiating these types of matter in a single specimen. [Preview Abstract] |
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A01.00037: Giving Vitamins to the Most Basic Bacterium Halona Dantes, Zaida Luthey-Schulten, Benjamin Gilbert This project revolves around the JCVI-syn3A and uses it as a platform to contribute to the understanding of the fundamental rules of life and how living things respond to changing environments and situations. The JCVI-syn3A is a minimal bacterial cell, i.e, it only contains genome essential for survival. The motivation behind the creation of the minimal cell is to create a simple cell that can be complexified to understand more complex cells and systems. This summer, we explored the JCVI-syn3A and used methods such as the Chemical Master Equation and Gillespie algorithm (a Monte Carlo Method for numerically generating trajectories of molecular populations) to simulate trajectories for processes such as the assembly of the ECF transporter. Due to the reduction in genome of the JCVI-syn3A, ECF transporters play an important part in the transportation of cofactors since the JCVI-syn3A cannot metabolize its cofactors and needs to transport cofactors from the external medium. Our aim was to simulate trajectories of the assembly of the ECF transporter under different conditions using Lattice Microbes (an implementation of the Gillespie algorithm using GPUs). From a biophysical standpoint, if we understand the assembly of such transporters, we can analyze the physical underpinnings of both their structure and the transportation they aide in. Future work may focus on determining the assembly models for all membrane protein complexes in the JCVI-syn3A and use these models for other complex cells. [Preview Abstract] |
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A01.00038: Cervical Cancer Detection Using Microwave Frequencies Grace Harley, Haider Raad Cervical cancer is one of the most common cancers in women worldwide. Current methods of diagnosis include a Papanicolaou (Pap) smear and a colposcopy/biopsy. Due to a varied water content in cancer tissues, cancer cells typically have a different set of dielectric values than healthy tissues. Our objective is to show whether it is possible to use electromagnetic waves at microwave frequencies to detect cervical cancer noninvasively and to propose a method that is cheaper/more accessible than current methods. Using CST simulation software to model human anatomy with correct dielectric values, we determined that a completely non-invasive approach was not possible as too much energy was lost in surface tissues before reaching the cervix when using an exterior approach. A trans-vaginal approach was found to have a good distinction between the healthy and cancerous models. This showed that cancer detection using microwaves is possible. [Preview Abstract] |
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A01.00039: Relaxation of a natural microbial ecosystem to a metabolic steady state Oshani Fernando, Alexander Petroff Ecosystems persist over geological time scales as organisms with complimentary metabolisms mediate nutrient cycles. The dynamics by which these cycles form and are stabilized remain poorly understood. Here we investigate the dynamics by which a natural microbial community, extracted from salt marsh sediment and containing oxygen consuming and oxygen producing microbes, relaxes to a metabolic steady state in a quasi-two-dimensional chamber. Filtered pore water continuously flows through the chamber, refreshing it at a rate of 0.8 1/hr. We measure the two dimensional distribution of oxygen at five minute intervals for several days, and infer the instantaneous rates of oxygen production and consumption. Preliminary results show that the metabolic activity of oxygen-producing and oxygen-consuming microbes relaxes to a steady state along a low dimensional trajectory. In future work, we will regularly extract DNA from the effluent to characterize the community dynamics both in the initial convergence to steady state and in the following days. [Preview Abstract] |
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A01.00040: Antimicrobial peptides derived from the SPLUNC1 protein perturb bacterial and eukaryotic lipid model membranes Tanvi Jakkampudi, Qiao Lin, Frank Heinrich, Aishwarya Vijai, Weiheng Qin, Ann Kang, Jespar Chen, Saheli Mitra, Robert Ernst, Peter Di, Stephanie Tristram-Nagle SPLUNC1 is a host defense protein found in the human respiratory. Five novel antimicrobial peptides (AMPs) were rationally designed from SPLUNC1 with different lengths, charges, hydrophobicities (H) and hydrophobic moments ($\mu $H). The goal of this study was to compare the biological activities of these AMPs by means of testing against paired clinical isolates of the Gram-negative (G(-)) bacteria. In addition, mechanistic studies were carried out to study interactions between the AMPs and bacterial lipid model membranes utilizing x-ray diffuse scattering (XDS), circular dichroism (CD) and neutron reflectivity (NR). One of the SPLUNC1-derived AMPs, A4-112, displayed superior antibacterial activity and the lowest toxicity to mammalian cells at low peptide concentration. CD indicated A4-112 has the highest $\alpha $-helical content and the lowest $\mu $H/H ratio. NR and XDS revealed A4-112 is located primarily in the headgroup region in a G(-) model membrane with only a shallow hydrocarbon penetration. XDS revealed that A4-112's mechanism of bacterial killing could involve domain formation with leakage of ions and water along the domain walls. A4-198, with the same amino acid composition but minimal $\mu $H, displayed the least helicity but with almost no bacterial killing activity, suggesting that helicity and effectiveness are correlated in these AMPs. [Preview Abstract] |
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A01.00041: Learning Continuous Chaotic Attractors with a Reservoir Computer Lindsay Smith, Jason Kim, Zhixin Lu, Dani Bassett Neural systems are well known for their ability to learn and store information as memories. Even more impressive is their ability to abstract these memories to create complex internal representations, enabling advanced functions such as the spatial manipulation of mental representations. While recurrent neural networks (RNNs) are capable of representing complex information, the exact mechanisms of how dynamical neural systems perform abstraction are still not well-understood, thereby hindering the development of more advanced functions. Here, we train a 1000-neuron RNN—a reservoir computer (RC)—to abstract a continuous dynamical attractor memory from isolated examples of dynamical attractor memories. Furthermore, we explain the abstraction mechanism with a new theory. By training the RC on isolated and shifted examples of either stable limit cycles or chaotic Lorenz attractors, the RC learns a continuum of attractors as quantified by an extra Lyapunov exponent equal to zero. We propose a theoretical mechanism of this abstraction by combining ideas from differentiable generalized synchronization and feedback dynamics. Our results quantify abstraction in simple neural systems, enabling us to design artificial RNNs for abstraction and leading us toward a neural basis of abstraction. [Preview Abstract] |
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A01.00042: Interplay of Mitochondrial Dynamics and Function in Cartilage Tissue Ashley Lasko, Ariel Bohner, Moumita Das, Michelle Delco Post-traumatic osteoarthritis (PTOA) results from joint trauma. While there are no current curative treatments for PTOA, research suggests that such treatments must target events shortly after injury. An early response in damaged cartilage tissue is mitochondrial dysfunction. In healthy cells, the mitochondrial population is likely to be dominated by healthy, larger fused mitochondria, while in populations that are largely unhealthy, mitochondria are smaller and unfused to be easily removed by mitophagy. The production of energy, glycosaminoglycan (GAG), and the control of reactive oxygen species (ROS) within cartilage are indications of cell health. To understand the dynamics of mitochondria in cartilage and its interplay with mitochondrial function and cellular health, we developed a mathematical model that describes the processes of mitochondrial biogenesis, fission, fusion, mitophagy, and includes the dynamics of energy production, GAG, and ROS.~We study this model with different initial conditions to determine which cases result in a healthy, a senescent, and a dead cell. Our results may help us understand what conditions must be met for a cell to survive mechanical stress, and how clinical treatments will preserve cell vitality after trauma. [Preview Abstract] |
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A01.00043: Effects of Silver and Magnesium ions on Bent DNA measured by Fluorescence Resonance Energy Transfer (FRET) Kaitlin Bullard, Yong Wang Studying DNA interactions is advantageous to developments in the medical field since DNA and its interactions effect our health greatly. Discovering new interactions or a further understanding of existing ones can lead to improved treatment options and preventative care. In addition, it is important to understand how the bendability of DNA depends on metal ions, which are essential for various fundamental processes in cells, including the formation of secondary and higher-order structures of nucleotides, DNA repair, and genomic stability. In this work, we investigated the effects of silver and magnesium ions on bent double-stranded DNA using self-assembled bent DNA molecules and FRET. We measured that the FRET efficiency decreased as the concentration of silver ions increased but increased at higher concentrations of magnesium ions. These observations suggested that silver ions destabilized the bent DNA, while magnesium ions increased the stability of the bent DNA molecules. There also seems to be a peak with the magnesium ions, suggesting an optimal amount of magnesium ions for bent DNA bonding. This peak is unexpected, thus further investigation is in progress. The current hypothesis is that magnesium promotes bonding by helping straighten out the bent DNA to form dimers and trimer but at some point, it makes the DNA too stiff. Compared to our previous work with gel electrophoresis, the FRET measurements were faster and simpler. This work is expected to contribute to a better understanding of the biophysical properties of double-stranded DNA, which will benefit DNA-related medical research and treatment development. [Preview Abstract] |
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A01.00044: The Potential role of the National Renewable Energy Laboratory (NREL) flagship tools in decision making under deep uncertainty Lucy Corthell The National Renewable Energy Laboratory (NREL) flagship tools currently model some amount of shallow uncertainty and may want to consider accounting for deep uncertainty as well. To determine if and how Decision Making under Deep Uncertainty (DMDU) methods could be incorporated into NREL flagship tools, I reviewed literature reports, interviewed tool developers, and looked at how these methods could be incorporated using case-study data from PRAS to see what is currently being done in terms of accounting for deep uncertainty and if there is a need to account for more deep uncertainty. I collected information from 9 different tools: PRAS, REopt, ReEDS, URBANopt, SAM, SLiDE, BSM, Tempo, and CELAVI and talked to 11 different tool experts to learn about (1) their tool(s), (2) if and how they currently incorporate uncertainty into their tool, and (3) if there is the need to incorporate DMDU methods into their tool. Out of 9 tools, I found that 7 tools account for shallow uncertainty while BSM and Tempo account for deep uncertainty. The trend was that tool developers thought trainings could be made available to NREL employees to allow for broader access to DMDU methods into all NREL flagship tools which could benefit NREL in becoming an expert among national labs in DMDU methods and analysis. Replace this text with your abstract body. [Preview Abstract] |
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A01.00045: What is the origin of optical emission in Cs2TiBr6? Emma Burton, Emma Pellerin, Maranda Allen, Caroline Jaeger, Erika Colin-Ulloa, Julia Martin, Lyubov V. Titova, Ronald L. Grimm Thin-film perovskite solar cells (PSCs) now rival established Si photovoltaics in efficiencies and could be less expensive with fewer resources required for processing.~ A major drawback of the leading PSCs is the presence of Pb in their structure, raising concerns about toxicity. Cs2TiBr6 is a leading candidate of Pb-free perovskites. It has a suitable band gap to be the top absorber in tandem-junction photovoltaics at \textasciitilde 1.8 eV, and Cs2TiBr6-based PSCs have demonstrated efficiencies up to 3.3{\%}.~ However, a complete view of the optical properties, carrier dynamics, and environmental stability remains incomplete. \newline \newline Herein, we use time-resolved photoluminescence spectroscopy to investigate optical emission and carrier lifetime in both large-grain and thin-film Cs2TiBr6 under different environmental conditions. Cs2TiBr6 demonstrates high stability in an N2 with photoexcited radiative lifetimes on the order of 0.5 ns, sufficient for photovoltaic consideration. We investigate the origins of several prominent emission features and their dependence of sample morphology as well as on environmental conditions. [Preview Abstract] |
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A01.00046: Preliminary Study of Multi-Electron Triggering in the Light Dark Matter eXperiment (LDMX) Megan Loh LDMX is a Stanford Linear Accelerator Center (SLAC) experiment designed to detect theoretical dark matter in the MeV to GeV mass range. The detector operates by shooting accelerated electrons through a target and measuring the momentum and energy loss after the electrons hit the target, aiming to capture energy loss due to dark bremsstrahlung. There are two main goals for the study, to optimize data collection in the trigger scintillator, and to explore the viability of multi-electron triggering. The incoming electron beam in the current design of the detector is characterized by a Poisson distribution of 1 electron incoming at a frequency of 35 MHz. Each event (electron hitting the target) includes 3.1 kilobytes of data. Recording all of the data from each event would cost 100 GB of data per second. Therefore, it is important to determine a cut-off point between the probable energy loss of a true dark bremsstrahlung event and energy loss from noise and background. The second part of the investigation is to explore multi-electron triggering: increasing the Poisson distribution of the incoming electron beam could increase the efficiency of the detector enormously, at the cost of potential overlaps in energy loss. [Preview Abstract] |
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A01.00047: Searching for Near-IR Fermi Arcs in a Photonic Chiral Woodpile Alison Weiss, Sachin Vaidya, Christina Jörg, Mikael Rechstman Topology in photonic platforms causes light to exhibit unusual transport properties. Weyl points are 3D topological degeneracies in the band structure of a periodic material and have been observed in chiral woodpile photonic crystals. Weyl points give rise to special surface states (Fermi arcs) that exist on the interface between a 3D photonic crystal and a different medium. Previous realizations of Weyl points and Fermi arcs were restricted to large scale structures that operated at microwave wavelengths. However, recent advances in 3D micro fabrication technology have brought the operating wavelength of these photonic crystals to mid and near infrared wavelengths. In this project, we simulate photonic crystal band structures using the MIT Photonic Bands package (MPB) to optimize the parameters of the crystal for observing Fermi arcs, and we compute the transmission spectrum for the optimized crystal using S4. We fabricate our crystals out of photoresist with a nanoscribe, and plan to coat our structures with titanium dioxide using an atomic layer deposition (ALD) machine to increase the effective refractive index contrast of the photonic crystal. We experimentally observe the transmission spectrum for our photonic crystals by using a Fourier Transform Infrared Spectroscopy (FTIR) device. Here we reproduce a previously published experiment observing a charge-2 Weyl point in the infrared using the FTIR and an uncoated photoresist chiral woodpile, an important calibration step for observing Fermi arcs in the coated structure. We also present a design for a fabricable chiral woodpile with potentially observable Fermi arcs in the near-infrared. [Preview Abstract] |
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A01.00048: Building Cesium Blue Magneto-Optical Trap Chitose Maruko, Will Williams Magneto-optical traps (MOT) are apparatus to laser cool and spatially trap neutral atoms with scattering forces and a spatially varying magnetic field. It has a wide application in variety of AMO experiments such as ultracold atom experiments, optical lattice clocks, neutral atom quantum computing, etc. Our goal is to construct the world's first Cesium MOT with a blue cooling transition, $6S_{1/2} F=4\rightarrow7S_{3/2} F=5$ , to make a visible optical cooling transition MOT available for undergraduate advanced laboratory classes. A Cesium MOT with this cooling transition has a loss channel due to occasional excitation of atoms to the $F=4$ state and subsequent decay to the $F=3$ ground state. We constructed an $852 $ nm tunable external cavity diode laser (ECDL) to drive the $6S_{1/2} F=3\rightarrow6S_{3/2} F=4$ transition. Using the constructed ECDL, we performed saturated absorption spectroscopy on the $6S_{1/2} F=3\rightarrow6S_{3/2} F=2, 3 ,4$ transitions to frequency stabilize the laser to the repump transition. [Preview Abstract] |
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A01.00049: Using a Spatial Filter to Reduce Noise in Optical Diffraction Katie Canavan, Raffaella Zanetti, Asia Baker, Sulekh Fernando-Peiris We analyze the locomotion of the nematode C. elegans, a microscopic worm the diameter of a human hair, using optical diffraction. These nematodes are commonly used as a simplified model for more complex organisms and aid in studying bodily systems such as neuronal pathways. For locomotion analysis, a laser is directed at the live worm, producing a dynamic diffraction pattern; this is useful because variations in light intensity at just one point in the diffraction pattern can reveal information about the entire time series, and the C. elegans’ overall movement. We modified and updated our optical setup by using a spatial filter and an assortment of lenses to prepare the beam so that a highly resolved diffraction pattern can be produced, using a human hair as a simulation of the worm. The spatial filter cleans the beam by shaping it into a consistent plane wave. It contains an objective lens, which diffracts the beam into a concentric pattern of rings around a central circle of light. Next, a pinhole allows only the desired central circle to pass through, improving the quality of the beam as it exits the spatial filter. As a result, the intensity distribution is uniform before it interacts with the diffracting object, allowing for the comparison to models of diffraction patterns. [Preview Abstract] |
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A01.00050: Entangled Photons from Cascade Decay of Hybridized and Dipole-Coupled Emitters Inci Anali, Derek Wang, Susanne Yelin One of the most versatile sources for entangled photons are emitters that interact via more than one tunable mechanism. Here, we demonstrate how hybridization and dipole-dipole interactions---potentially simultaneously available in colloidal quantum dots and molecular aggregates---leveraged in conjunction can couple simple, well understood emitters into composite emitters with flexible control over the level structure. We show that cascade decay through carefully designed level structures can result in emission of frequency-entangled photons with Bell states and three-photon GHZ states as example cases. These results pave the way toward rational design of quantum optical emitters of arbitrarily entangled photons. [Preview Abstract] |
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A01.00051: Faraday Rotation in Air: Combining Brute Force and Finesse Terry Chavez, Shaun Schrubbe, William Brandon Because of the weak circular birefringent response to axial magnetic fields, and hence low values of the Verdet constants, only a few research groups have successfully measured non-resonant Faraday Rotation in diamagnetic gases. In contrast to those complicated schemes, we utilized a straightforward technique resulting in accurate measurements of the Faraday rotation in air. Our method combines brute force (a magnetic field intensity of around 210 gauss over a 60 cm length), and finesse (differential phase sensitive detection), resulting in accurate values for the Verdet constant of air, $V_{air,}$ at a dozen wavelengths ranging from 405-800 nm, which can be modeled as a mixture as $V_{air} =$ (0.7809 $V_{N2} \quad +$ 0.2095 $V_{O2})$. [Preview Abstract] |
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A01.00052: Illuminating C. elegans Locomotion with Laser Diffraction Raffaella Zanetti, Katherine Canavan, Asia Baker, Sulekh Fernando-Peiris, Jenny Magnes Studying the locomotory patterns of the nematode C. elegans helps researchers better understand how the neuronal dynamics of more complex animals like humans function through the simplified model organism. We observe worm locomotion using video tracking and laser diffraction. The latter of these techniques is particularly advantageous because diffraction can resolve subtle changes in motion to the level of the wavelength of the light —greater resolution and precision than that of an optical microscope. Additionally, one point in the laser diffraction pattern is a superposition of all points in the worm and therefore can give information about the shape and dynamics of the entire sample. We created an optical setup to illuminate a model hair and used a CCD camera to record dynamic diffraction patterns. Experimental data is analyzed using Matlab code that creates a time series of pixel intensity at each frame for two specifically chosen pixels in the videos. We found that this method of creating and analyzing diffraction patterns accurately represents the sample’s movement as indicated by chaotic markers such as Largest Lyapunov Exponents. This experimental time series is compared with that of computer simulations of the worm to gauge the accuracy of our current understanding. [Preview Abstract] |
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A01.00053: Doubling Cavity for Atom Interferometry with Momentum Squeezed States for Gravitational Sensing Sophie Li Atom interferometers are evolving rapidly and are used in a variety of applications in fundamental physics such as the precise measurements of gravitational constants, curvature and, more recently, waves. The Kasevich group has begun constructing a new atom interferometry experiment based on Strontium with the objective of using spin squeezing to demonstrate quantum-enhanced inertial sensors. The experiment will incorporate a large-momentum-transfer (LMT) Bragg interferometer on the 461nm $^{1}S_0$$\leftrightarrow$$^{1}P_1$ transition in $^{88}$Sr to coherently generate and control well defined atomic momentum state superpositions. A ring resonator with a bow-tie configuration was designed, built and optimized to convert 922nm light from a Ti:Sapph laser to 461nm. The Pound-Drever-Hall technique was implemented to lock the cavity resonance to the laser frequency. Up to 1W of 461nm light was produced with a conversion efficiency of 60%. Noise suppression was achieved by stabilization with acousto-optic modulators. Second harmonic generation was also achieved with a periodically-poled crystal in a single-pass configuration. [Preview Abstract] |
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A01.00054: Clouds, Cameras, and Composition: Characterizing spectral differences between co-located Pandoras Margaret Turcotte Seavey, Alexander Kotsakis, Joseph Robinson, Robert Swap Pandora spectrometer instruments are built and calibrated the same way, however there is variability in total column nitrogen dioxide (NO$_{2})$ between co-located Pandoras. The causes of spectral differences between co-located Pandoras should be characterized to quantify and reduce these differences. This characterization results in a better understanding of the instrument and how atmospheric and instrumental variability can impact retrieved NO$_{2}$. There are a variety of factors that can contribute to spectral differences between co-located Pandoras. Clouds never appear in perfect shape and there are different cloud types that form at different altitudes. Instrumentation setup affects the retrieved total column NO$_{2\, }$because the optional camera searches for the greatest light input while the traditional non-camera Pandora instruments searches for the Sun using calculated sun position based on latitude and longitude. It has been observed that total column NO$_{2\, }$observations by co-located Pandoras capture identical characteristics throughout the day but there are instances where the delta between observations is different. We can reasonably say that NO$_{2}$is heterogeneous by nature and through a combination of these factors leads to the delta being different between co-located Pandoras. Future work is needed to further quantify the impacts of the field calibration reference, cloud optical thickness, and hyperlocal NO$_{2\, }$heterogeneity on the correlation between co-located Pandoras. [Preview Abstract] |
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A01.00055: Fabricating metalenses with Nanoscribe Yangheng Jizhe Our group is dedicated to fabricating otpical metamaterials using the technique of Two-Photon-Polimerization (TPP) with Nanoscribe. We have tested the limits of Nanoscribe to produce nanopillar structures, reported aspect ratios up to 5, with a minimum lateral resolution of 300 nm, and been using GWL scripts to extend the capabilities of nanoscribe beyond traditional print sets. Furthermore, we have successfully printed structures incorporating large scale arrays of arbitrary 2d elements other than cylindrical pillars (we have printed tori ). Pillars and toris have been used in metalenses as building blocks, thus our results will provide a pathway for the reliable and faster deposition (than standard e-beam lithography) of optical metamaterials. We would like to acknowledge Dr. Joel K.W.Yang, Dr. Hao Wang, and their groups for providing us with guidance for gwl scripting. [Preview Abstract] |
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A01.00056: Quantum bounds for discriminating mixed states generated by weak measurements and thermal noise Piper Wysocki, Jonathan Habif, Tracy McAskill The problem of optimally discriminating between known non-orthogonal quantum states has many important applications in both quantum communications and quantum computation. However, non-orthogonal states cannot be discriminated perfectly, resulting in much work on finding the quantum bounds of discrimination with minimal error. Discrimination of pure states is well understood, but little research has been done on discriminating mixed states. We compute quantum bounds for discriminating between mixed states that were prepared by a pure state mixed with thermal noise light in a channel versus the same pure state subject to weak measurement in a channel. We calculate the Helstrom bound for this discrimination problem when only one copy of the quantum state is available for measurement, and the quantum Chernoff bound, for the case when copies of the quantum state occupy many modes and can be measured individually or with a joint measurement. These results have utility in disambiguating between an attacker in a quantum key distribution system with weak measurement capabilities versus thermal noise in the channel. [Preview Abstract] |
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A01.00057: Magneto-Optical Materials for Future Gravitational Wave Detectors Mariam Mchedlidze, Ariella Hernandez, Rodica Martin Gravitational waves are novel astronomical tools for observing the dynamic side of the Universe. Unlike light-based telescopes that observe stars and galaxies in electromagnetic waves or light, gravitational-wave detectors such as the Laser Interferometer Gravitational-wave Observatory (LIGO), are 4 km-long Michelson interferometers that use infrared lasers and light interference to sense gravitational waves from merging black holes, or colliding neutron stars. Detected for the first time in September 2015, gravitational waves carry information that cannot be obtained in any other way, helping our understanding of their origins and of the Universe. With more sensitive detectors, we could observe gravitational waves from even further sources. Our research focuses on the development of one key device that contributes to improving the sensitivity of these detectors – a Faraday isolator. This device uses a magneto-optical material that helps control the polarization of light when applying an external magnetic field. Improved Faraday isolators require high transparency, effective polarization control, and minimal distortion of the transmitted beam. Cerium Fluoride (CeF3) is one promising magneto-optical candidate, and we will be characterizing its properties in our study. [Preview Abstract] |
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A01.00058: Optical Optimization for Pump-Probe Spectroscopy Jessica Jenick One important technique for materials characterization is that of pump-probe spectroscopy, which allows us to understand the interactions and characteristics of excited materials under light illumination. The goal of this project was to design and build a pump-probe optical setup for single shot spectroscopy of phase change materials. This setup requires that a sample be pumped by a blue laser to instigate thermal processes, and then probed by a white lamp to look for the spectral shifts as a function of time and optical power. Through the careful use of lenses and mirrors, we were able to refine our optical setup to get acceptable power levels and useful spot sizes to match a white light probe beam with a blue light pump. We have been able to overcome difficulties regarding the use of a white lamp with poor spatial coherence. Building on what has been learned through building this initial setup, we will be able to improve it over time. This setup can later be used with the spectrometer built by the physics department for the further experimentation. [Preview Abstract] |
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A01.00059: Correlation Between Polarization-based Geometric Phase of Light and Geodesic Triangle on Bloch(Poincare) Sphere Cody Leary, Raisa Tasnim Raofa We investigate how photons can remember their polarization states using a dual path Sagnac interferometer where a split beam of light is passed through a birefringent crystal to change the polarization along one axis, then recombine the beam and analyze the "memory" of this polarization shift. We then analyze how the change in polarization imparts an overall geometric phase on the system by observing the output intensity. We show how the phase is related to a geodesic triangle on a Bloch (Poincare) Sphere. [Preview Abstract] |
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A01.00060: Can Wettability Predict Cell Adhesion? Using Laser Ablation to Improve the Biointegration of Titanium Implants. Julia Wright The speed and effectiveness of cell adhesion on an orthopedic implant can significantly affect a patient's recovery time and the long-term performance of the implant. Recently, laser ablation has been suggested as a method of texturing these implants to improve cell adhesion. However, different techniques and parameters for ablation can yield much finer or rougher surface textures. Directly testing the biocompatibility of these different surfaces by placing and growing cells on them is a tedious and time-consuming process. However, an alternative to this could be determining the wettability of the surface as measured by the contact angle between the edge of a water drop and the surface. This is a quicker macroscopic measurement that would allow us to efficiently characterize a wide variety of ablation parameters. So far, we have found that cell count increases dramatically at a very specific contact angle and set of ablation parameters. Therefore, we are now attempting to replicate these results for a different ablation pattern in order to show whether cell adhesion improves at this same contact angle regardless of ablation parameters. In my poster presentation I will discuss our results so far, and their implications, as well as future plans for the project. [Preview Abstract] |
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A01.00061: Switchable Wettability of Laser Ablated Brass for use in Oil/Water Separation Cassie Stoffer, Michaela Kleinert The pressing issue of cleaning up oil spills has created a demand for an efficient, affordable, and environmentally-friendly method of separating oil and water. Fine meshes made of laser ablated brass have the potential to achieve this goal. The surface chemistry and morphology of brass are altered when it is ablated with a laser, resulting in hydrophobic and oleophilic properties that allow this material to effectively separate oil and water. We change the wettability of laser ablated brass from hydrophobic/oleophilic to hydrophilic/oleophobic by altering the surface chemistry of the brass via heat treatment at $300^{\circ}$C. The wettability of brass is switched back to its original hydrophobic/oleophilic state as the heated sample is exposed to air and a partial deoxidation occurs on the surface. The change in wettability is quantified using a goniometer: a newly improved instrument that allows us to accurately measure the advancing and receding contact angles of a droplet of water on a brass surface. Future project improvements include altering the switchable wettability cycle to improve time efficiency. This simple switchable wettability process can be used to create brass meshes that can be cleaned, recovered, and reused many times for optimized oil/water separation. [Preview Abstract] |
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A01.00062: Biomimicry of Fish Scales to Design an Environmentally Friendly Mesh to Aid in Oil Spill Clean Up~ Madolyn Kelm Oil spills are both detrimental to marine ecosystems and difficult to clean up. Conventional clean-up methods are often inefficient and harmful to the environment, leading researchers to look ``outside'' the box for new methods - to nature. While many forms of wildlife, such as birds, become debilitated in the presence of oil, fish - even though still damaged by the \textit{chemical }effects of the contamination - remain largely clean. This is because fish scales have unique oleophobic, or oil repelling, and hydrophilic, or water-attracting properties, that only become apparent underwater. This property is largely attributed to the microscopic structures found on fish scales. Using biomimicry, we can recreate these microstructures of the fish scales through the process of laser ablation. Over the summer we started exploring how altering the laser scan speed and the metallic properties of our samples affects the wettability. We improved our wettability measurement system to quantify not only the in-air hydrophobicity of our samples, but also quantify the inverse relationship of the underwater hydrophilic/oleophobic properties that are observed by fish scales. This is an important first step in determining how effective our laser ablated samples will be at oil/water separation. [Preview Abstract] |
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A01.00063: Rotational Dynamics of Asymmetric Molecules Madeline Killian, Varun Makhija In nature, light is constantly interacting with molecules (natural processes like vision or photosynthesis). Understanding these interactions gives us more insight into what our world is made up of. When light hits a molecule, it is absorbed by the electrons in the molecule. The overarching research goal of our research is to make a ``movie'' of the electrons after light hits the molecule by using a femtosecond (a millionth of a billionth of a second) laser pulse. A molecule's natural rotation creates a blur in this movie. The goal of this research is to understand the rotation of the asymmetric chloroethylene (C$_{2}$H$_{3}$Cl) molecule in order to get rid of the blur it creates in the electron movie. Similar research has been previously conducted for the symmetric molecule ethylene (C$_{2}$H$_{4})$. The asymmetry of C$_{2}$H$_{3}$Cl results in complicated probability distributions for rotational orientation after a laser pulse hits the molecule. We solve the Time Dependent Schrodinger Equation to determine these probability distributions computationally for C$_{2}$H$_{4\, }$and C$_{2}$H$_{3}$Cl. The results show that for C$_{2}$H$_{3}$Cl there is a highly asymmetric distribution of probabilities and a unidirectional rotation; this is not observed in C$_{2}$H$_{4}$. This is the first step towards being able to image electronic motion in C$_{2}$H$_{3}$Cl. [Preview Abstract] |
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A01.00064: Angular Momentum Coherences in Vibrational Molecular Dynamics Zoe Rafter, Varun Makhija Molecular dynamics describes what happens inside of a molecule (clump of atoms) after some amount of energy is dumped into a system, for instance when light is absorbed by a molecule. In natural systems, this absorbed energy often needs to transfer locations. The vibration of atoms in a molecule is believed to facilitate this transfer. In a particular excited state of the molecule of Nitrogen Dioxide (NO2), the bending and stretching of bonds is known to transfer energy from one vibrational state to another. This energy transfer is called Fermi Resonance. One potential way to image this vibration of a molecule is using ultrashort laser pulses. Ultrashort laser pulses last approximately a millionth of a billionth of a second, and act as a very short ``flash'' of a camera, during which the vibrations of the molecule are frozen. Such an experiment was recently attempted; however, the molecules were arbitrarily oriented and angular momentum was not considered. This arbitrary orientation effectively ``blurs'' the image. To remove this ``blur'', a calculation of the excitation step, including angular momentum must be carried out. Therefore, we include the angular momentum states of NO2 and computationally simulate the vibrational motion including angular momentum in the excited state. [Preview Abstract] |
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A01.00065: Characterization of Femtosecond UV Pulses using an Autocorrelator. Catherine Mikhailova, Zane Phelps, Surjendu Bhattacharyya, Anbu Venkatachala, Daniel Rolles The characterization of ultrafast laser pulses is essential for determining the scope and capability of ultrafast experiments. Using an autocorrelator and subsequent data analysis techniques, we developed a robust and wavelength-independent measurement of both pulse duration and chirp for sub-100 fs UV pulses. [Preview Abstract] |
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A01.00066: Investigating Molecular Gas Properties of Class 0 Source CARMA-7 Makoto Johnstone Previous observations of the low mass Class 0 protostar, CARMA-7, in the Serpens South cluster region detected outflow ejection events traced by $^{12}CO$ J=2→1. However, little is known about the molecular abundances and morphologies of molecular lines other than carbon monoxide isotopologues. We present follow-up observations of 9 molecular emission lines near CARMA-7 using the Atacama Large Millimeter/sub-millimeter Array. We confirm the presence of a bipolar outflow extending in the north-south direction with a position angle of 4$^{\circ}$ as traced by $^{12}CO$ J=2→1, $H_{2}CO$ 3(0,3)-2(0,2), and $H_{2}CO$ 3(2,1)-2(2,0). Further investigation of the $H_{2}CO$ and $c-C_{3}H_{2}$ lines uncovered a low velocity extended emission feature slanted to the southwest with a position angle of 72$^{\circ}$. We interpret this feature as a potential accretion flow, but further analysis via modeling is necessary. The $C^{18}O$ 2→1 emission line shows early signs of Keplerian rotation in the disk/envelope. However, other known disk and envelope tracers such as $^{13}CO$, $N_{2}D^{+}$, and $H_{2}CO$ fail to show signs of rotation. We find that CARMA-7 does not hold a disk larger than 305 AU and that the detection of a strong outflow is not a clear indicator of an evolved disk. [Preview Abstract] |
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A01.00067: Detecting EMRIs in Gravitational Wave Data with Harmonic Structure Naomi Shechter, Shane Larson Gravitational waves, like electromagnetic waves, transmit radiation with information about the source encoded within, and Extreme Mass Ratio Inspirals (EMRIs) are one such source. EMRIs are compact stellar mass objects which spiral inward toward a massive or supermassive black hole; as the orbit decays, the object's waveform maps out the changing spacetime of its environment. The launching of LISA will allow physicists to collect gravitational wave data from these populous sources, clarifying our understanding of extreme relativistic conditions and the evolution of supermassive black holes. This poster illustrates an EMRI analysis technique called harmonic correlation, which will be useful for the detection of EMRI signals even at a low SNR ratio. To investigate the effectiveness of this method under different conditions, we simulated a gravitational waveform and noise, then ran the simulated data through a harmonic correlation with a variety of EMRI parameters and signal strengths. Our results confirmed that harmonic correlation will be a useful technique to streamline the analysis of LISA data and the detection of EMRI signals.~ [Preview Abstract] |
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A01.00068: Relating Adaptive Optics and Image Quality for Exoplanet Detection Ollie Jackson When you look up at the stars to watch them twinkle, you are actually observing the star's light waves become distorted by fluctuations in our atmosphere as they reach our eyes. Our telescopes also capture the twinkling of stars, which makes it incredibly difficult to get useful science images of our universe, particularly when we try to take pictures of exoplanets. Adaptive Optics (AO) is a system built into modern telescopes that directly corrects for the distortions of incoming lightwaves through the use of a wave sensor and a deformable mirror that is reshaped to counteract the changes in light caused by our atmosphere. A properly functioning AO system is key to exoplanet research, but according to a 2020 study by Cantalloube et. al. on the Chilean SPHERE VLT telescope, high wind speeds in our atmosphere can create a ``wind-driven halo'' of light in images as the AO system becomes overwhelmed, making it impossible to examine the region for exoplanets. This displays how our atmosphere not only distorts incoming lightwaves, but also impacts how well the AO system can correct those distortions. My research focuses on understanding the relationship between weather conditions, AO, and image quality at the W. M. Keck Observatory to determine what weather conditions limit the performance of Keck's AO system and what weather conditions limit our ability to image exoplanets. My initial findings show that the direction of wind flow has an effect on correlations between weather, image quality, and AO readings. [Preview Abstract] |
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A01.00069: Spectral Mapping Using CRISM Data in the Northwest Noachis Region. Jessica Harryman, Kim Seelos, Debra Buczkowski, Christina Viviano Launched in 2005, the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) is an instrument that measures the composition of Mars's surface and allows scientists to understand climate patterns that relate to the presence of water on the planet. Our effort consisted of assisting in ongoing mapping by validating and compositionally mapping using CRISM images in three unique areas: Northwest Noachis Terra (this work), Terra Sabaea, and Central Valles Marineris. Spectral analysis utilizing image analysis software of each regions of interest were compared with reference spectra in the MICA library, a compilation of the best CRISM end member mineral detections, in order to identify and label minerals in the regions of interest. Compositionally, the NW Noachis Terra region revealed large amounts of low calcium and high calcium pyroxene (LCP and HCP, respectively), magnesium smectite, and iron smectite. This concentration of minerals suggests an aqueous past, as smectite phyllosilicates generally form as a result of aqueous alteration. [Preview Abstract] |
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A01.00070: Dwarf Spheroidal Galaxy Dispersions Calculated with the MOND External Field Effect Noshin Yesmin, Will Snider, Dr. S. G. Alexander We present calculated dispersion profiles of four Milky Way dwarf spheroidal satellite galaxies, which include the Modified Newtonian Dynamics (MOND) external field effect (EFE). Our model of dwarf spheroidal galaxies (dSphs) contains ten thousand stars, and the internal gravity of the dwarf is modeled as Plummer potential. In addition, we treat the host galaxy as a fixed point mass whose gravitational field is not affected by the dwarf galaxy. We calculate the motion of the 10k stars for several billion years, and then calculate time-averaged bulk dispersion and dispersion profile statistically. We include results for Newtonian gravity, isolated MOND, and EFE MOND and compare them to observations. [Preview Abstract] |
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A01.00071: Searching for Stars Disrupted by a Supermassive Black Hole That Lived to Tell the Tale Rewa Clark Bush, Samantha C. Wu, Ariadna Murguia-Berthier, Rosa Wallace Everson, Enrico Ramirez-Ruiz The center of the Milky Way is a crowded place--a swarm of millions of stars orbiting a central supermassive black hole. It is estimated that approximately once every 100,000 years, a star's orbit may veer close enough to the black hole that it becomes severely altered by gravitational effects, yet not so close as to fall in. During this close encounter--called a ``tidal disruption event'' (TDE)--extreme tidal forces exerted on the star cause it to lose mass and gain energy. A TDE may span mere hours; they are so transient that we rarely observe one in action. But what if we could locate the remnants of these events, the hundreds of thousands of stars in the Milky Way that may have survived a TDE and lived to tell the tale? What stories might they bring us from some of the most energetic encounters with extreme gravity? Our research aims to study the long-term evolution of TDE star remnants computationally, with the goal of determining strategies to find them observationally. We used initial hydrodynamical models of TDE remnants that were then mapped into a stellar evolution code to examine the properties of these stars millions, and even billions, of years after the initial disruption event. [Preview Abstract] |
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A01.00072: Electromagnetic Detectability of Binary Supermassive Black Holes with the Vera Rubin Observatory Kaylee Grace, Megan Davis, Jonathan Trump Supermassive black holes (SMBHs) can end up as binary pairs through galaxy mergers and are important sources of gravitational waves. Although several binary candidates have been identified in previous work, none have been fully confirmed, yet. These pairs are difficult to detect since accreting, single SMBHs can have pseudo-periodic light curves due to stochastic noise that can mimic the signature of binary SMBHs. The Vera Rubin Observatory (VRO) will be critical for getting the data necessary to confirm the existence of binary SMBHs. The false-positive binary detection rate for VRO can be determined by attempting to recover sinusoidal binary signals, represented by either a smooth sine wave or a sawtooth wave, within simulated light curves. In this project, we simulated over four million light curves for VRO and have applied computationally inexpensive analysis methods to recover the simulated signals. Understanding the false-positive detection rate of these objects by VRO is vital for the detection confirmation that has eluded us thus far. [Preview Abstract] |
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A01.00073: MWEST: Cosmological Zoom-in Simulation Suite of Milky Way-like Dark Matter Halos with Large Magellanic Cloud and Gaia-Enceladus Analogs Deveshi Buch, Ethan Nadler, Risa Wechsler, Yao-Yuan Mao The growth of galaxies is closely connected to the dark matter halos---gravitationally bound regions of dark matter---that surround them. Cosmological simulations of halos with characteristics similar to the halo of our own galaxy, the Milky Way (MW), provide valuable insights into our home in the Universe. Observations suggest that the most massive galaxies that currently orbit or previously merged with the MW, the Large Magellanic Cloud (LMC) and Gaia-Enceladus (GE) respectively, have a significant impact on the formation of the MW; including these in simulations can contribute to a more realistic picture of MW evolution and dynamics. Thus, we present MWEST: a unique high-resolution zoom-in simulation suite of 25 MW-like systems, each selected with LMC and GE analogs in its formation history. We find that systems matching these specific MW-like criteria are rare, constituting only $\sim$ 1\% of all systems in the relevant mass range. This simulation suite will be useful for a range of applications in understanding our galaxy and placing it in a cosmological context, from analyzing dark matter structure to uncovering the building blocks of the MW. [Preview Abstract] |
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A01.00074: The Fates of Star-Forming Satellites Around the Milky Way Debosmita Pathak, Charlotte Christensen, Alberto Munoz, Courtney Carter Why do the Milky Way and Andromeda host so few star-forming satellites, in contrast to the Milky Way-analogues of the SAGA-II survey? Differences in which satellites survive and which get disrupted by the host halo environment directly impacts what satellites we observe. To that end, this project analyzes the infall properties of the surviving and disrupted satellites around four high-resolution simulated Milky Way analogues to understand which satellites survive and which get disrupted. We find that progenitors that are massive enough to sustain star-formation after infall are preferentially disrupted by the host. Earlier infall times and lower tangential velocity components at infall also contribute to the preferential disruption of some satellites. Looking at the full sample of surviving and disrupted satellites around the Milky Way can give us perspective on how unique the Milky Way's satellite population is and the processes that were necessary to produce this distribution. [Preview Abstract] |
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A01.00075: Nonlinear Dynamics from Early Dark Energy Ericka Florio, Mary Gerhardinger, Tom Giblin Currently, cosmologists do not agree on how quickly the universe is expanding. This problem, called the Hubble tension, describes the fact that two independent types of measurements of the current expansion rate of the universe (called $H_0$) give two different values; with the newly-released Gaia measurements of $H_0$ (Reiss et al. 2020), the Hubble tension now stands at 4.2$\sigma$. The Early Dark Energy (EDE) theory is a proposed solution to this tension which introduces a scalar field to the $\Lambda$CDM Universe around matter-radiation equality (Poulin et al. 2019). Certain favored models of the EDE field have been shown to display nonlinear resonance, which could have left an imprint on the late Universe. My research partners and I have implemented the EDE model in GABE, a computer program which evolves scalar fields on cosmological scales and is specifically designed to study nonlinear dynamics. We have integrated the EDE field alongside matter and radiation fluids on a perturbed gravitational metric, in order to determine whether the cosmological temperate maps produced by our simulation match the Universe that we observe, and in this way falsify or support the EDE theory as a resolution to the Hubble tension. [Preview Abstract] |
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A01.00076: Projection Effect in TNG Simulations Alessia Molino, Heidi Wu, Rosana Lenhart One of the major goals in cosmology is to study how the observed galaxies in clusters are associated with the underlying dark matter. However, galaxies that are farther away from each other but appear at the same location in the sky can be mistaken to be in the same galaxy cluster. This phenomenon is called the projection effect. In order to study this problem we use the IllustrisTNG simulations, a state-of-the-art public simulation suite. We quantify how the projection effect changes the richness and gravitational lensing of galaxy clusters. Richness refers to the amount of galaxies that are associated with an individual galaxy cluster, and we calculate richness under different observational conditions. We study the gravitational lensing signal associated with those different richness definitions and use our result to interpret observed gravitational lensing signals. [Preview Abstract] |
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A01.00077: Vibrational and Rotational Spectral Data for Possible Interstellar Detection of AlH$_{3}$OH$_{2}$, SiH$_{3}$OH, and SiH$_{3}$NH$_{2}$ Alexandria Watrous, Brent Westbrook, Megan Davis, Ryan Fortenberry This is the first full set of vibrational and rotational spectral data needed to aid in the detection of AlH$_{3}$OH$_{2}$, SiH$_{3}$OH (silanol), and SiH$_{3}$NH$_{2}$ (silylamine) in astrophysical or simulated laboratory environments through the use of quantum chemical computations at the CCSD(T)-F12b level of theory employing quartic force fields for the three molecules of interest. Previous work has shown that SiH$_{3}$OH and SiH$_{3}$NH$_{2}$ contain some of the strongest bonds of the most abundant elements in space. AlH$_{3}$OH$_{2}$ also contains highly abundant atoms and represents an intermediate along the reaction pathway from H$_{2}$O and AlH$_{3}$ to AlH$_{2}$OH. All three of these molecules are also polar with AlH$_{3}$OH$_{2}$ having the largest dipole of 4.58 D and the other two having dipole moments in the 1.10--1.30 D range, large enough to allow for the detection of these molecules in space through rotational spectroscopy. The molecules also have substantial infrared intensities with many of the frequencies being over 90 km mol$^{-1}$ and falling within the currently uncertain 12--17 $\mu $m region of observed infrared spectra. [Preview Abstract] |
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A01.00078: Polarization Angles for Simons Observatory Detectors Rainier Naylor This poster chronicles the investigation into polarization angles of detectors for the Large Aperture Telescope Receiver tester (LATRt), which is being installed in Atacama, Chili. The LATRt group at University of Chicago has been working for several years testing various properties of the detectors of an optical tube to ensure that they’re in working order when the telescope is constructed. In this project, I used a sparse wire grid polarizer (SWGP) to determine the polarization angle of individual detectors in the LATRt optics tube. The SWGP was placed directly atop the test cryostat and rotated a constant pace. From the combination of detector measurements and the spatial rotation of grid, I plotted sine waves of grid angle vs intensity of signal. These sine waves were fitted to determine the offset angle, which corresponds to the initial polariza-tion angle. I was able to map the locations of detectors to their corresponding polarization angles, ensuring that the projected angles match the design. The project additionally tested the best way to run the wire grid polarizer, giving the development team a chance to advance their product before it goes to the field, to be used as calibration for further polarization [Preview Abstract] |
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A01.00079: The Stochastic Gravitational-Wave Background from Stellar Core-Collapse Events Bella Finkel, Haakon Andresen, Vuk Mandic The collapse of massive stars is a dynamical, aspherical, and stochastic process which produces gravitational radiation with a waveform representative of the physics of the collapse. We estimate the stochastic gravitational-wave background arising from all core-collapse supernovae in the universe based on the gravitational wave signal predictions of recent numerical simulations. We focus on the signals from slowly and non-rotating progenitors which are expected to constitute the vast majority of stellar core-collapses, but we also compute the background expected from rapidly rotating and highly massive progenitors as extreme-case limits. Our computations are made under the assumption that each progenitor model describes all core-collapse events in the universe, so our results demonstrate the range of possible backgrounds in which the ``true'' background from core-collapse may lie. Our most realistic estimates are two or more orders of magnitude below the sensitivity the third-generation terrestrial gravitational wave detector Cosmic Explorer. [Preview Abstract] |
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A01.00080: Detecting Sources in Fermi Gamma-ray All Sky Maps Using Neural Networks Diana Horangic, Elena Orlando, Andrew Strong The Fermi Large Area Telescope (LAT) has been in orbit of Earth since 2008. One challenge in analyzing LAT data is localizing sources to answer how many gamma ray sources are in Fermi's view. Neural networks, a new development in data analysis, show impressive accuracy in the field of medical imaging. Application of these networks to Fermi LAT data can potentially be more successful than traditional statistical methods of source detection. We present, here, our first attempt to improve traditional methods with a region-based convolutional neural network (Faster R-CNN) and then a Mask R-CNN. We have generated three training and test datasets of simulated Fermi LAT images with different parameters such as noise and photon counts. These were used to separately train Facebook AI's Mask R-CNN model with a ResNet-50 backbone and feature pyramid network for instance segmentation of sources. Results of this analysis are presented. [Preview Abstract] |
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A01.00081: Architecture and Design of a Small Parallel Supercomputer for Modelling Bolometric Lightcurves of Type II-P Supernovae Hypatia Meraviglia, Jeremy Lusk, Chris Geske, Zachary Humphrey, Dakota Leslie, Erik Stinnett Processing raw luminosity of supernovae into lightcurves across a range of observed and unobserved wavelengths requires integration across individual wavelength windows to establish luminosity over a broad range. Martinez et al. (in review, 2021) detail a variety of methods for bolometric lightcurve computation. Different portions of the curve may be modelled simultaneously, making parallel computing potentially useful for lightcurve computation. We have built a six-node small parallel supercomputer (SPS@UCA) to accommodate the bolometric lightcurve computation program SuperBoL (Lusk and Baron, 2017) and future computationally-intensive projects. We present its architecture, design, and specifications, its uses for both computational astronomy and outreach, and a discussion of ongoing modelling. [Preview Abstract] |
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A01.00082: Modeling the Variability of the Sun's Total Solar Irradiance through Supervised Machine Learning Techniques Ashley Lieber, Laura Sandoval, Joshua Elliott, Wendy Carande With the Sun being Earth's main source of energy and heat, it is critical to understand how and why it varies. The primary objective of this project was to create a machine learning regression model that predicts the total solar irradiance (TSI) and to analyze the contributions of solar features in driving change of the Sun's TSI. This improves upon the previous model by incorporating machine learning techniques on a wider array of data. We utilized the technique of multiple linear regression to have the model predict an irradiance value for a given day based on given solar features. The features we initially considered were the sunspot area and seventeen space weather parameters. These features were visible in intensitygrams and line-of-sight magnetograms from the HMI instrument aboard SDO and include information on active regions (AR) on the Sun's surface and space weather parameters. We then used the TSI Composite Data to compare the model's predicted TSI values with the actual TSI values. Due to the number of features, a correlation matrix was used to eliminate unnecessary features. Preliminary results show that training the model on these features yields a root mean squared error of 0.052 showing that the model is performing as expected in this early stage.~ [Preview Abstract] |
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A01.00083: Comparing the Distributions of Dark and Visible Matter in Galaxy Clusters in Search of DM Self-Interaction Isabel Horst, Shenming Fu, Ian Dell'Antonio I investigate the role of dark matter (DM) in galaxy cluster formation and look for evidence of dark matter self-interaction by comparing the spatial distributions of dark and visible matter within massive galaxy clusters. Using data from the Local Volume Complete Cluster Survey (LoVoCCS) and the Large Survey of Space and Time (LSST) Science Pipelines software framework, the Brown Observational Cosmology Group has mapped mass distributions within several nearby galaxy clusters, which are around 80{\%} DM by mass, via weak gravitational lensing. I compare this lensing signal with data from the Chandra X-Ray Observatory, which correlates to only visible matter, by plotting the locations of the strongest weak lensing and strongest X-Ray signal relative to the brightest central galaxy in each cluster. Any pattern in the distributions of DM, gas, and galaxies in these clusters may give us insight into the role of dark matter in galaxy cluster evolution. [Preview Abstract] |
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A01.00084: X-ray and multiwavelength observations of the potential AGN in UGC 9367 Rujuta Purohit, Ryan Hickox Supermassive black holes are found at the centers of most massive galaxies. The accretion of gas onto such a black hole is called an active galactic nucleus (AGN) that emits radiation over many different wavelengths. Dwarf galaxies, in particular, are potentially interesting hosts for AGN, as they may contain black holes that have not grown significantly since the epoch of their formation in the early Universe. UGC 9367 is a dwarf galaxy in the Bo\"{o}tes constellation that has signatures of potential AGN based on its X-ray and optical line properties. It has a mass of about 10$^{9}$ M$_{o}$ and a redshift of 0.34. We calculate the mid-Infrared and the [O III] luminosities and compare these to the observed X-ray luminosity, in reference to established relationships in literature. We also plot the spectral energy distribution and the BPT diagram for the galaxy to better understand its nature. These provide significant evidence for the fact that UGC 9367 hosts an AGN that is relatively unobscured by gas and dust and represents the very few to be detected in dwarf galaxies using X-ray observations. [Preview Abstract] |
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A01.00085: Galileons and Gravity: Improving Computational Simulations Mary Gerhardinger, Tom Giblin While Einstein’s theory of gravity has been tested through experiments, his theory of General Relativity is not compatible with other ideas in physics, such as Quantum Mechanics. Hence, more rigorous study is necessary. In this project, we studied a place of extreme gravity, two binary stars orbiting each other, in order to test the limits of GR. Specifically, I performed computational simulations of these stars in the presence of 15 scalar and vector degrees of freedom to determine how they interact. I implemented this model into GABE (Grid And Bubble Evolver), a numerical tool which solves for the interaction of scalar fields in an expanding universe. I refined this program, adding equations of motion, outgoing boundary conditions, and power calculations. Finally, I compared this output to the full numerical solution to determine both the validity and usefulness of my own code and found a UV complete model improves code stability and reduces computational costs. [Preview Abstract] |
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A01.00086: Statistical Multi-Component Fitting in the Orion A Molecular Cloud Ruby Fulford, Brian Svoboda, David Meier, Juergen Ott Though integral to the structure and chemical composition of our universe, the details of high-mass star formation remain an open problem. The Integral Shaped Filament (ISF) of the Orion A Molecular Cloud is the closest massive star forming region to Earth, and is therefore essential to the study of massive star formation. We use NestFit, a Bayesian software framework for spectral line decomposition, to fit up to two gas velocity components to observed NH$_{3}$ inversion spectra from the Green Bank Ammonia Survey. We compare the results of our model to the single-component fits of Friesen et al. (2017) to determine whether assuming a single velocity component biases model parameter estimates. We find that the resulting gas property distributions are very similar between the one- and two-component models. The two-component model does, however, show a peak in velocity dispersion near the thermal sound speed not seen in the one-component results, indicative of non-turbulent, thermal gas. Maps of the velocity dispersion show that regions of transonic gas correspond to denser regions of Orion A that are likely to be star-forming. The excess of gas near the sonic speed in dense regions over previous analyses suggests a greater quantity of gas unstable to gravitational collapse in Orion A. [Preview Abstract] |
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A01.00087: 3D Shapes of Galaxy Clusters in Illustris-TNG Simulations Rosana Lenhart Galaxy clusters are the largest structure in the universe, and the 3D shape and orientation of these galaxy clusters impacts the gravitational lensing signal which can be used to study the formation of structure in the Universe. However, the 3D shape has primarily been studied in dark matter-only simulations--without taking into account the impact of the gas and stars. IllustrisTNG is a public project containing 18 hydrodynamic simulations of large sections of the universe. We determine the 3D shape of the clusters contained in the simulations. This work compares how the shape is affected~ by the presence of gas and stars, the resolution of the simulation, and the specified radius measurement. We find that gas tends to make clusters more spherical, while higher resolution tends to make clusters more elliptical. In addition, by using different radii for measuring the shape we found clusters are more spherical at larger radii. [Preview Abstract] |
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A01.00088: PyNu: Developing a Search Pipeline for Gravitational-Wave and Neutrino Coincident Events in the Era of Multi-Messenger Astrophysics Viviana Caceres, Hannah Griggs, Shamita Hanumasagar, Laura Cadonati Numerical relativity predicts that the merger of two binary neutron stars (BNS) or a binary neutron star and a black hole (NSBH) emits large amounts of neutrinos, in addition to a gravitational wave. However, a joint detection of astrophysical neutrinos and a gravitational wave produced by a compact binary coalescence (CBC) has not been made. We modify the gravitational wave pipeline PyCBC, used with LIGO data, to search for a CBC coincident in time with neutrinos detected by the Ice Cube Neutrino Observatory. We reduce the amount of data used in a search run and the PyCBC waveform template bank used to include only neutron star mergers. We also inject a BNS waveform into data from LIGO’s second observing run to study the limitations of the pipeline’s detection capabilities. The search runs took between 12 and 24 hours, and injected signals were clearly detected up to a coincident signal-to-noise ratio of approximately 7. Further modifications to the pipeline will include reducing the on-source window and considering the neutrino arrival direction, which are expected to make the pipeline quicker and more efficient when running. [Preview Abstract] |
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A01.00089: Modeling and Manufacturing Baffle Panels to Reduce the Impact of Sidelobes in CMB Telescopes Kate Okun Three Mirror Anastigmat (TMA) and Cross-Dragone (CD) Cosmic Microwave Background (CMB) telescopes experience a substantial reduction in image quality caused by significant sidelobe pickup. TMA and CD telescopes have specularly reflecting internal walls that can amplify the effects of the scattered light entering the instrument at wide angles, thus worsening the resulting sidelobes. We aim to reduce the contrast of the sidelobes by lining the cabin in white noise surfaces, called baffle panels, designed to scatter light over a wide range of angles, thus diffusing the sidelobe specular peaks into a DC base. Our research focuses on modeling the scattering caused by the white noise surfaces using phase-sensitive ray tracing and manufacturing such surfaces at a larger scale. We hope to see our analytical model confirm our previous experimental results from the 90-110 GHz range. [Preview Abstract] |
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A01.00090: Detonation of a White Dwarf Star: Simulations of the Sub-Chandra Type Ia Supernovae Melissa Rasmussen, Michael Zingale A type Ia supernova can result from the double detonation of a white dwarf star below the Chandrasekhar mass limit. Using the hydrodynamics code Castro, we simulate this detonation by perturbing a carbon/oxygen white dwarf with an accumulated shell of helium, with a small amount of nitrogen-14. In this work, we investigate the robustness of the model. Adjusting the location of the perturbation affects whether detonation occurs. Changing the composition of the helium shell affects the speed at which it burns. The size of the reaction network used affects whether the star's core burns immediately or from a shock wave from the shell. This last result is particularly notable, as it indicates that using reaction networks which leave out heavier elements may be an oversimplification, producing results with significant disparities from more thorough simulations. [Preview Abstract] |
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A01.00091: ALMA ACA CO Observations in Isolated Galaxy Pairs: the Low Mass Picture Swetha Sankar, George Privon, Sabrina Stierwalt Analyses of pair galaxy interactions provide a critical picture of dynamics influencing gas and stellar buildup in low-mass, metal-poor environments. Previous probing of low-redshift TiNY Titans dwarf galaxy pairs (10$^{7}$ M$_{\odot}$ $<$ M $<$ 10$^{9.7}$ M$_{\odot}$; 8.0 $<$ Z $<$ 8.9) via the Sloan Digital Sky Survey found enhanced star formation rates with separation distances R$_{sep}$ $<$ ~100 kpc. Whether this star formation is a result of an increased H$_{2}$ mass or efficiency in which the H$_{2}$ is converted to stars remains unclear. For the first time, we present ALMA Atacama Compact Array molecular gas quantities of these dwarf galaxy pair systems with close separations (6 kpc $<$ R$_{sep}$ $<$ 48 kpc) via the CO tracer. CO is detected in four galaxies, and an application of the Milky Way accepted $\alpha_{CO}$ results in molecular gas calculations of ~10$^{8}$ M$_{\odot}$. A comparison of molecular gas and stellar formation rate to the xCOLDGASS (10$^{9}$ M$_{\odot}$ $<$ M $<$ 10$^{11.5}$ M$_{\odot}$) data set does not identify higher H$_{2}$ nor efficiency in these dwarfs. This preliminary study thus demonstrates the feasibility of measuring H$_{2}$ reservoirs in dwarfs, with future studies aimed at constraining molecular gas mass at lower metallicity environments. [Preview Abstract] |
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A01.00092: New Radio Observations of Galactic Supernova Remnants G28.6-0.1 and G32.4+0.1 Madeleine Edenton, David Moffett, Thomas Pannuti, Christina Lacey, JohnPaul Sleiman, Taylor Deneau, Relmond Van Daniker Supernova remnants (SNRs) that exhibit X-ray spectra dominated by synchrotron radiation are crucial laboratories for the study of cosmic-ray acceleration by this class of sources. However, despite the discovery of synchrotron X-ray emission from the archetypal source SN 1006 over two decades ago, the number of Galactic SNRs of this class remains small. Combining X-ray observations of candidate members of this class with long wavelength radio observations holds the promise of applying robust constraints on fits to extracted X-ray spectra. Such fits can provide estimates of the maximum energies of cosmic-ray electrons accelerated by these sources and thus investigate the association between SNRs and the knee energy of the cosmic-ray spectrum. In this presentation, we describe new L-Band (1500 MHz) and P-Band (300 MHz) observations made with the VLA of two candidate and known Galactic SNRs, G28.6-0.1 and G32.4+0.1. We have applied synchrotron models to these spectra using constraints; namely, derived flux densities and spectral indices obtained from the L-Band and P-Band observations. Initial results will be presented and discussed. [Preview Abstract] |
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A01.00093: Pulse Profiles and Polarization of the \ter Cluster Pulsars Ashley Martsen, Scott Ransom Terzan 5 is a globular cluster in our galaxy that is home to 39 millisecond pulsars. The Terzan 5 pulsars are faint, and in general the polarization data has too low S/N ratios to be able to be analyzed. We combined over eleven years worth of archival GBT data to create high S/N profiles for the majority of the pulsars in the Terzan 5 cluster. Due to an instrumental issue, some of the polarization information was contaminated and was excluded from the polarization profiles. We also created higher S/N Total Intensity pulse profiles using all the data including the contaminated data, as the total intensity data was uncontaminated by the instrumental issues. We created both high S/N polarization and total intensity profiles for 34 pulsars in the Terzan 5 cluster in two different frequency ranges. From these high signal to noise profiles, more precise DM values were found for each pulsar and 29 pulsars had RM values calculated, which allowed for a map of the parallel component of the galactic magnetic field to be created. [Preview Abstract] |
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A01.00094: Stellar Population Synthesis in BST1047$+$1156 Keri Wood, Chris Mihos We are creating sample stellar populations to model potential formation scenarios of the galaxy BST1047$+$1156 in preparation for Hubble data coming in mid-2022. BST1047$+$1156 is an ultra-diffuse galaxy found in the Leo I galaxy group. With very blue optical colors and far ultraviolet emission, this galaxy has likely experienced a recent burst of star formation. However, the density of gas in the galaxy falls well below levels at which star formation is typically observed, making its star formation history especially intriguing. The galaxy could have been an established low surface brightness galaxy involved in a tidal interaction, or it could have been recently born from the tidal debris of the Leo I group. An older LSB with a recent interaction would have a mix of young and old stellar populations, while a recently formed tidal dwarf would only have young stars. By estimating and comparing the relative fractions of old and young populations, we hope to learn more about the history of this galaxy.~~ [Preview Abstract] |
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A01.00095: Search for the origin of a site-wide, 4.2 Hz feature in ground motion at LIGO Livingston Observatory Priti Rangnekar A low-frequency feature in ground motion in the range of 4.1-4.2 Hz has been observed sitewide at LIGO Livingston. Early research, which focused on using spectrograms for short timeframes, found the feature to be intermittent in its amplitude and slightly variable in its precise frequency. We first develop a computational pipeline to acquire spectrum data for the feature's frequency and amplitude over time. Observed hints of periodicities are analyzed through Lomb-Scargle periodograms. We then extract its angle of incidence using the beam rotation sensors (BRS) and determine correlations, if any, with wind, temperature, and anthropogenic factors. Based on directional information acquired from this data analysis, we construct a plan for deploying a sensor array at LIGO Livingston, consisting of 15 L22 sensors and dataloggers, to collect more specific data. Locations for sensors are determined by transfer function computations yielding hints of relative phasing and time delay between site stations. Ultimately, this project will assist efforts to make adjustments to the detector and improve its sensitivity with respect to low-frequency noise. Our general procedure also provides an efficient and comprehensive mechanism to analyze similar features from unknown sources in the future. [Preview Abstract] |
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A01.00096: Gaseous Halos of Simulated Milky Way-like Galaxies Bhavya Pardasani, Andrew Wetzel, Jenna Samuel As satellite galaxies fall into the host halo, they interact hydrodynamically with the host galaxy, causing them to be stripped of their gas and subsequently cease forming stars. In order to investigate the role of the host halo in quenching satellite galaxies, we have characterized the halos of 14 Milky Way-like host galaxies from the FIRE simulations from $z=0$ (present day) to $z=1.76$ (10 Gyr ago). We have quantified the gas density of the host halo environment with respect to both distance from the host and galactocentric latitude. In general, the gas density decreases with increasing distance from the host and most of the halo gas profiles are well fit by a broken power law. At earlier times, the density in the inner regions of the host halos was enhanced relative to $z=0$. This implies that an earlier infalling satellite experienced more ram-pressure stripping and was more efficiently quenched compared to a satellite that fell in later. We also find that in the inner halo of some hosts at $z=0$ the density is larger close to the plane of the host galaxy disk versus above or below the disk, so satellites that orbit at lower galactocentric latitudes may be more efficiently quenched as well. [Preview Abstract] |
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A01.00097: Stellar Rotation in Praesepe's Tidal Tails Jessica McDivitt, Stephanie Douglas, Jason Curtis, Mark Popinchalk, Alejandro Nunez As open clusters orbit, gravity distorts the cluster, stripping stars from its core and forming tidal tails. Recent studies have identified candidate tidal tail members whose former membership in the cluster core can be verified through analysis of stellar rotation periods. Magnetized stellar winds slow a star's rotation over time. Consequently, in open clusters like Praesepe, stars tend to exist on either a fast or slow rotator sequence following a pattern unique to that cluster's approximate age. A cluster's color-period plot can serve as an age indicator, and tidally stripped stars should follow the same distribution as stars in the cluster core. We select 96 candidate tidal tail members observed by the Transiting Exoplanet Survey Satellite (TESS). We use a Python GUI to extract and detrend light curves, and to measure rotation periods. \quad We measured reliable rotation periods for 32 stars, while 64 light curves had inhibiting systematic issues. By comparing the TESS periods for our targets to published K2 periods for members in the cluster core, we conclude that our 32 new rotators are consistent with past membership in the Praesepe cluster. Based on this success, we suggest that stellar rotation offers an effective method for confirming past members dispersed into tidal tails. [Preview Abstract] |
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A01.00098: Finding EMRIs in Simulated LISA Data August Muller In preparation for the upcoming Laser Interferometer Space Antenna (LISA) mission, the LISA Data Challenges pose a series of open questions on how to extract gravitational wave (GW) signals from simulated LISA data. Solving these challenges is essential to demonstrating effective analysis methods for the mission in the mid-2030s. As the LISA mission will detect GW signals in a new frequency range, a variety of previously undetected GW source types will be present in the LISA data. One such source type is that of extreme mass-ratio inspirals (EMRIs), inspiraling binary systems where a stellar mass object is orbiting a super-massive black hole. This project seeks to use Markov Chain Monte Carlo (MCMC) algorithms to develop a reliable method for identifying EMRI signals and extracting their source parameters. [Preview Abstract] |
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A01.00099: Identity Theft: The Story of How Dark Energy Masqueraded as Matter and Radiation Batia Friedman-Shaw, Morgane Konig The universe has gone through three main stages in its history: the radiation dominated era, the matter dominated era, and the dark energy dominated era. It is composed of about 68{\%} Dark Energy (DE), 5{\%} baryonic matter, while about 27{\%} is Dark Matter (DM). Though cosmologists understand the makeup of baryonic matter and radiation of the universe, the jury is still out on which substances make up the DE and DM. In recent years, a beyond the standard model pseudoscalar called an axion has emerged as a candidate for DE and DM. Our project is focused on examining if this axion could be a compelling DE candidate. Axions are created at the time of inflation. If DE is indeed an elementary particle, we need to explain how it remained undetected during the previous stages of the history of the universe.~ One possible mechanism, known as a tracker behavior, describes a field that behaves like the dominating component of the universe. In this scenario, this axion would have stayed under the radar during the radiation and matter era. Only later would this particle start behaving as DE signaling the beginning of the DE era. This scenario is known as DE Quintessence. We also investigated attractor behavior of our model: Attractors are states to which a system is naturally drawn to regardless of the initial conditions. Putting these behaviors together, we are examining if the proposed pseudoscalar axion can be a candidate for DE Quintessence. [Preview Abstract] |
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A01.00100: Replace this text with your abstract title. Anika Goel, Allison Kirkpatrick, Kevin Cooke Replace this text with your abstract body. [Preview Abstract] |
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A01.00101: Fiber Positioner System: A Method to Guide 30,000 Optical Fibers. Kimika Arai We want to build a spectroscopic telescope, which is a tool that analyzes the light of the universe. The purpose of this study is to understand the feasibility of using piezoelectric tubes (piezos) as a method of positioning 30,000 optical fibers. The goal is to precisely move and position the fibers to a given location within 10um, and let them stay in that position for at least an hour. However, piezos have the properties of hysteresis and creep, which makes this significantly more challenging to do so. To combat these obstacles and gain better control of the piezos, it is necessary to learn the characteristics and quirks of the system. Therefore, this project focused mainly on understanding the behavior of the piezos under a changing voltage, as well as attempting hysteresis mitigation by experimenting with reset procedures, which, as the name implies, seeks to “reset” any memory that the system has of the previous state. Experiments showed that we can locate the fibers with a precision of 50um in one movement. [Preview Abstract] |
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A01.00102: Measuring the Electric Field During Thunderstorms by the Telescope Array detector~ Kaleigh O'Brien, Rasha Abbasi, Hans Johnson, Joe Mazich, Nour Husseini Acquiring knowledge of electric field strength and structure inside a thunderstorm is key to understanding lightning and thunderstorms' impact on the development of cosmic showers. Given data from the Telescope Array Surface Detector (TASD), we observed variations in cosmic ray shower intensity. These variations were found to be on average between 0.5-1{\%} with and up to 2-3{\%}. These observations were detected in both deficit and excess. The rate variations were also correlated with lightning and thunderstorms. In order to more closely study these variations, we ran low- and high-energy simulations of electric fields within thunderstorms using CORSIKA. These simulations yielded a reasonable result of electric field magnitude variations between 0.2-0.4V, which in turn has informed our understanding of the electric field within storms and its effect on cosmic ray showers.~ [Preview Abstract] |
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A01.00103: Magnetic Fields in Diffuse Interstellar Gas: Comparing Starlight Polarization, Polarized Dust Emission and Neutral Hydrogen Orientation Sally Jiang, Susan Clark, Gina Panopoulou The Galactic magnetic field affects many processes in the interstellar medium (ISM), such as star formation and the flow of interstellar gas. The plane-of-sky magnetic field orientation is probed by the alignment of dust in the ISM, which absorbs and polarizes background starlight, and also emits partially polarized thermal radiation. The polarization fraction of dust can also be used to probe the degree of disorder in the magnetic field, both along the line of sight and within the telescope beam. Filaments of neutral hydrogen (HI) are found to be, on average, parallel to the plane-of-sky magnetic field in diffuse regions (Clark et al 2014). We explore starlight polarization and HI orientation as a function of the dust polarization fraction at high Galactic latitudes. We find that on average, regions of high dust polarization fraction have a higher degree of alignment between HI orientation and starlight polarization angles compared to low dust polarization regions. We interpret regions of lower dust polarization as having less coherent plane-of-sky magnetic field structure, likely due to the 3D magnetic field geometry. We investigate whether there is evidence for a physical loss of alignment between HI orientation and the magnetic field in select regions. [Preview Abstract] |
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A01.00104: Theoretical Lightcurve Predictions of Kilonovae from Component Mass Distributions Gargi Mansingh, Andrew Toivonen, Michael Coughlin Kilonovae are dramatic explosions that can result from the merger of compact objects: two neutron stars, or a neutron star and a black hole. They can produce both a gravitational wave (GW) and an electromagnetic (EM) signal. In addition to GW observations being crucial for locating the kilonova, as they are dim and short-lived, combining these observations yields great insights. Whether or not a binary merger produces a detctable kilonova depends on the mass ejecta stripped dynamically or that forms an accretion disk around the remnant object. Kilonovae are of particular interest as they are a possible site for r-process nucleosynthesis, where the heavy elements in the universe may be formed. The mass ejecta primarily depends on the type of merger, BNS or NSBH, the component masses of the merger, and the tidal deformability of the neutron star(s) involved, which itself depends on the equation of state of neutron stars. Here, we are implementing expectations for detectable kilonovae, including low-latency estimates for kilonovae based on initial data products. In order to get the most information out of these events as possible, we must combine GW and EM observations. [Preview Abstract] |
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A01.00105: Exotic Dynamics in the Early Universe Could Explain Cosmological Mystery: Resolving the Hubble Tension with the Early Dark Energy Monodromy Potential Shar Daniels, Tristan Smith, Alexa Bartlett The Hubble Tension implies that our understanding of cosmology may be incomplete. This tension is a discrepancy between the expansion rate of the universe today inferred from direct measurements and the value predicted from observations of the afterglow of the Big Bang. The Hubble Constant ($H_{0})$ is measured to be 74\textpm 1.4 km/s/Mpc from observations of the present-day universe given by the SH0ES absolute luminosity calibration of type Ia supernovae. The measured anisotropies of the Cosmic Microwave Background using the Planck satellite and assuming the standard cosmological model predict the~value of $H_{0}$ is 67.8 \textpm 1.3 km/s/Mpc. An intriguing proposition to bring these values into accordance is ``early dark energy'' (EDE): a scalar field in the early universe that temporarily accelerates its expansion and then dilutes away, leaving few traces. We explore the novel Monodromy model of an EDE scalar field as a potential resolution to the Hubble Tension by coding the Monodromy model into the linear perturbation Boltzmann code CLASS and executing Markov Chain Monte-Carlo simulations to explore the parameter space. We find the most improvement to $H_{0}$ with a value of the free parameter $q$ of $q=$.10 ($H_{0}=$72.53 km/s/Mpc) and a likewise improved $H_{0}$ of 71.85 from $q=$1.0, whereas $q$'s greater than 1.0 correspond to lower values of $H_{0}$. These results show the potential of the EDE Monodromy model as an improvement over Lambda CDM to address the Hubble Tension. [Preview Abstract] |
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A01.00106: Exploring the Spectra of Very-High-Energy Gamma-Ray Blazars Daniela Hikari Yano, Reshmi Mukherjee Blazars are active galactic nuclei (AGNs) that launch relativistic jets directed toward us and comprise the majority of the detected very-high-energy (VHE) gamma-ray sources. The curvature of blazar’s energy spectrum can give us information about particle acceleration, cooling mechanisms, and gamma-ray propagation, consequently, allowing us to explore the mysteries of the physical mechanisms in jets and the intervening space between the source and the observer. The gamma rays are attenuated through pair production with the extragalactic background light (EBL), leading to electromagnetic cascades that can be affected by the intergalactic magnetic field (IGMF). These effects can be reflected in the curvature of the energy flux spectrum. This study uses data collected by Fermi-LAT and VERITAS observatories over a period of ten years. Fermi-LAT is a space-based observatory that detects gamma rays with energies from 50 MeV to 1 TeV and VERITAS is a ground-based observatory that detects VHE gamma rays with energies from 85 GeV to 30 TeV. Spectral analyses were done for a sample of bright TeV blazars. We expect that this joint analysis of the chosen blazars will allow us to learn more about the cooling mechanisms in the jet, and the strength of the IGMF. [Preview Abstract] |
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A01.00107: Analytic Approximations for the Velocity Suppression of Dark Matter Capture Jillian Paulin, Cosmin Ilie Compact astrophysical objects have been considered in the literature as dark matter (DM) probes, via the observational effects of annihilating captured DM. In this paper we investigate the role of stellar velocity on the multiscatter capture rates and find that the capture rates of DM by a star moving with respect to the DM halo rest frame are suppressed by a predictable amount. We develop and validate an analytical expression for the capture rate suppression factor. This suppression factor can be used to directly re-evaluate projected bounds on the DM-nucleon cross section, for any given stellar velocity, as we explicitly show using Population III stars as DM probes. Those objects (Pop III stars) are particularly interesting candidates, since they form at high redshifts, in very high DM density environments. We find that previous results, obtained under the assumption of star at rest with respect to the DM rest frame are essentially unchanged, when considering the possible rotational velocities for those central stars. [Preview Abstract] |
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A01.00108: Discovering Lyman Alpha Emitting Galaxies at a Redshift of 4.5 Shreya Karthikeyan, Eric Gawiser, Rameen Farooq, Barbara Benda, Adam Broussard, Arjun Dey, Kyoung-soo Lee, Vandana Ramakrishnan Hydrogen Lyman-$\alpha $ (Ly$\alpha )$ emission has been a vital tool in surveying the high-redshift universe for galaxy evolution. Of interest are Ly$\alpha $ emitting galaxies (LAEs), young star-forming galaxies that trace large-scale structure in the high-redshift universe. The One-hundred-square-degree DECam Imaging in Narrowbands (ODIN) survey uses the Dark Energy Camera (DECam) to collect deep images of seven fields in the 673nm narrowband filter, corresponding to the Ly$\alpha $ line at a redshift of 4.5. We search for excess narrowband flux density that would reveal Ly$\alpha $ emission for over two million galaxies. We refine the candidate sample by requiring a color excess corresponding to the rest-frame equivalent width (EW) of \textgreater 20{\AA}, to remove continuum-only objects and reduce contamination from lower-EW objects. The derived estimates for EW and Ly$\alpha $ luminosity show reasonable distributions, with a median Ly$\alpha $ luminosity of 7.78 x 10$^{42}$ erg/s. We mask the selection field in regions of known bright stars to reduce clustering bias from bright-star artifacts. We find a final sample of approximately 4,000 LAE candidates at z $=$ 4.5. We aim to further refine the sample by eliminating possible contamination from galaxies emitting singly-ionized oxygen to improve the LAE catalog for clustering analysis. [Preview Abstract] |
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A01.00109: An Analysis of Eclipsing Binary Systems Exhibiting the O'Connell Effect Allison Helferty, Annika Stare Over half of the stars in our galaxy are binary stars, which consist of two stars orbiting their common center of mass. Eclipsing binaries are variable stars that appear to overlap each other from the Earth's vantage point. One complete cycle includes two eclipses: the primary eclipse, in which the brighter star is obscured, and the secondary eclipse, in which the fainter star is obscured. Some binaries also have a difference in their maxima due to the O'Connell effect, a yet unexplained phenomenon. The O'Connell effect is counterintuitive, as the orientation of adjacent stars should not affect their intensity. In our research, we analyzed the light curves of several beta Lyrae and W Ursa Majoris type eclipsing binaries that exhibit the O'Connell effect. Using the program VSTAR and Excel's Solver tool, we obtained a Fourier fit for their light curves and estimates for the difference in maximum brightness. We will present raw light curves for these binaries along with calculated fits and differences in magnitude. A comparison between our new data and previous observations from the literature can reveal how the orbital period and difference in maximum brightness change over time. [Preview Abstract] |
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A01.00110: Analysis of Sky-localization Capability of Lunar Gravitational Wave Antenna Ana Carolina Oliveira, Marica Branchesi, Jan Harms The study of gravitational waves (GWs) is a rapidly expanding field, and the development of new technologies is a big step towards the advancement of knowledge about these cosmic ripples and their sources. The Lunar Gravitational-Wave Antenna (LGWA) is a proposed GW detector located on the Moon that will operate with an antipodal pair of high-sensitivity seismometers monitoring the vibrational normal modes of astronomical objects. This project examines the sky-localization ability of the proposed Moon-located detector, with a structure of 4 seismometers located on the lunar South Pole. The analysis is conducted through the expansion of an algorithm that uses the Fisher matrix approach for statistical analysis of signals, modifying it to process calculations for detectors in selenographic coordinates. The algorithm runs analyses on models of BBH and BNS sources, estimating the sky-localization of real astrophysical sources detectable by LGWA. Results show that LGWA is able to make 12 detections per year for BBH signals with SNR$>$7, out of 1719 signals with redshift (z) $<$0.4, with 7 detections being localized within 1 deg$^{2}$. For BNS, LGWA detects 2 signals per year above the same SNR threshold, out of 14421 signals with z$<$0.4, with 1 detection localized within 1 deg$^{2}$. [Preview Abstract] |
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A01.00111: Merger Signatures of Cold Quasars in the Distant Universe Casey Carlile, Allison Kirkpatrick, Eilat Glikman Quasars have historically been found in galaxies with very little star formation, however, a recently discovered group of quasars called cold quasars has between four to seven times the amount of star formation than similar unobscured, blue quasars. Cold quasars could be an intermediary step in quasar evolution between red quasars and blue quasars or a unique population of objects that will form compact starburst galaxies. I analyzed images of cold quasars from the Hyper Suprime-Cam on the Subaru Telescope to look for signs of galaxy mergers in the disk of their host galaxies. This project may show that cold quasars are triggered by galaxy mergers and are either an earlier stage of quasar evolution or a unique population of quasars. [Preview Abstract] |
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A01.00112: The Rotation Curve of the Milky Way Galaxy as Evidence for Dark Matter Rebekah Polen, Huma Jafree We present neutral hydrogen (HI) observations of the Galactic plane taken between $0^{\circ} < l < 80^{\circ}$ galactic longitude on the 20-Meter Telescope at the Green Bank Observatory. These radio spectroscopic signatures returned the 21-centimeter line of HI at various offsets due to the Doppler Shift. Calculating an orbital speed relative to the Galactic center, velocity was plotted against radius to map the rotation curve of the Milky Way Galaxy. Classical mechanics suggests that velocity should fall off at large distances, but empirical observations show otherwise. An abundance of mass which cannot be detected is responsible for this phenomenon, known as dark matter. Although undefined, dark matter is easily indirectly observed by galactic rotation curves. Our observations confirm that the velocity of the Milky Way's disc is fairly constant even at large distances from Sagittarius A*. [Preview Abstract] |
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A01.00113: Mapping the Milky Way using the final data release of APOGEE Cathryn Price, Jon Holtzman Mapping properties of the stellar populations across the Milky Way is an effective way of gaining a better understanding of the formation and evolution of the Galaxy. Using the final data release of the SDSS Apache Point Observatory Galactic Evolution Experiment (APOGEE-2) survey, which uses high-resolution stellar spectra in the near-infrared to determine stellar parameters and chemical abundances, we present maps of metallicity and age across the Galaxy, concentrating on the disk. We investigate radial gradients and azimuthal symmetry of mean metallicity and age, as well as the radial dependence of the age and metallicity distribution functions. [Preview Abstract] |
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A01.00114: Calculating Velocity to Find Distance to YellowBalls to Build a Catalogue That Aids the Research of Massive Star Formation Bezawit Mekasha Kassaye, Hritik Rawat, Kathryn Devine YellowBalls (YBs) were first discovered by citizen scientists in mid-infrared images from the Spitzer Space Telescope. Their yellow color comes from a combination of green (8 $\mu$m) and red (24 $\mu$m) emission. The combined emission suggests ionization and heat, respectively, which are signs of newly forming massive or intermediate-mass stars. YBs are a potentially useful tool to expand our knowledge of star formation. We are building a catalog of YBs that includes their location, distance, size, color, mass, and luminosity, providing data for astronomers to use to learn more about YBs’ role in star formation. Distance is a crucial property to determine physical properties such as luminosity and size. I used data from the SEDIGISM and BU-GRS datasets to analyze $^{13}$CO spectra at the locations of YBs. Doppler shift of the $^{13}$CO lines indicates YB velocities. I then used the location of YBs in the Galactic plane along with Velocities in a distance calculator that combined a kinematic rotational model of the Milky Way and the Bayesian statistics to determine distance. I have determined the velocities and distances for $\sim$4000 YBs, which will be included in our final catalog. [Preview Abstract] |
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A01.00115: ~Collaborative Coding for Quasar Observations with the James Webb Space Telescope Lily Whitesell, Hadley Lim NASA's next flagship observatory, the James Webb Space Telescope, is planned to succeed the Hubble Space Telescope and is a joint NASA-ESA-CSA astrophysics mission. The Early Release Science Program Q3D will be one of the first observing programs scheduled on the telescope and will study quasars in three dimensions. In collaboration with scientists from other institutions and Professor David Rupke, we translated ISFIT, integral field spectroscopy fitting software, from the scientific programming language IDL to Python. [Preview Abstract] |
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A01.00116: Investigating the Star Formation History of Active Galactic Nuclei Hosts Over Cosmic Time z $=$ 0-2.5 Rachel Cionitti Active Galactic Nuclei (AGN) are supermassive black holes at the centers of galaxies, which are actively accreting matter. They are some of the brightest objects in the universe, which makes them perfectly suited for investigating cosmic history. This research focuses on the relative amounts of star forming and quiescent (non-star forming) galaxies hosting AGN from redshift 2.5 to 0. This analysis is performed by creating UV-VJ diagrams for each epoch of time units z$=$0.5. These diagrams have a visible threshold that indicates whether a galaxy is star forming or quiescent. This research indicates that galaxies hosting AGN do not evolve similarly to typical galaxies that have undergone the same analysis. While typical galaxies from the same redshift range have been observed to begin at z$=$2.5 as star forming and quiescent equally, and over time separate into a strictly bimodal distribution of both states. My research shows that AGN begin as mostly star forming and evolve slowly over time to be a more collective distribution straddling the line between quiescent and star forming but moving into quiescence. This implies that AGN may have a profound effect on star formation. [Preview Abstract] |
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A01.00117: Clustering Analysis of Lyman Alpha Emitters in the COSMOS Field at z=3.1 and z=4.5 Barbara Benda, Eric Gawiser, Rameen Farooq, Shreya Karthikeyan, Adam Broussard, Arjun Dey, Kyoung-Soo Lee, Dustin Lang, Byeongha Moon, Changbom Park, Vandana Ramakrishnan, Frank Valdes, Yujin Yang Lyman alpha emitting galaxies (LAEs) are a useful tool for tracking galaxy evolution. Since the Lyman alpha (Ly𝛼) emission line is easily quenched by dust, galaxies detected via this line are nearly dust-free. LAEs are young galaxies in an early burst of star formation that track large scale structure in the distant universe. The One-hundred square-degree DECam Imaging in Narrowbands (ODIN) survey is collecting narrowband images of seven different fields with three filters that correspond to the Ly𝛼 line at certain redshifts. Combined with publicly available broadband images, this allows for color selection of LAEs. We use LAE catalogs at z=3.1 and z=4.5 to study spatial clustering of LAEs in the COSMOS field. We measure angular correlation functions for each LAE sample and fit them with a power law minus integral constraint model. We calculate the expected redshift distribution from the LAE luminosity function at the appropriate redshifts and the measured filter bandpass. Using the expected redshift distributions, we will forward-model the predicted dark matter correlations to infer the LAE bias values on large-scales. [Preview Abstract] |
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A01.00118: Optical and X-ray Follow-Up to a Globular Cluster Ultraluminous X-ray Source in NGC 4472 Wasundara Athukoralalage, Stephen Zepf, Kristen Dage The question of whether or not black holes are hosted by globular clusters is one of the leading open questions in Astronomy. While globular clusters are ``black hole factories" through normal stellar evolution, some theories predict that black holes will be ejected early in the history of the globular cluster. However, recent observational work and theoretical studies in the last 15 years have suggested that this may not be the case, and studies of ultraluminous X-ray sources in extragalactic globular clusters have provided evidence of some of the most exotic black hole candidates in globular clusters. We have evidence that one of these sources might be an intermediate black hole. [Preview Abstract] |
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A01.00119: Investigating the Thermodynamics and Seismic Profile of the Europan Hydrosphere through Pure-Water Modeling and Saltwater Experiments Samantha Rosenfeld, Heather Watson Europa is a prime candidate for the search for life beyond Earth due to its theorized subsurface liquid-water ocean. We perform a computational analysis of the thermodynamic properties for a pure-water Europan hydrosphere using a Python programming framework called SeaFreeze, creating four models of the ice shell assuming surface temperatures of 50K and 140K and ice shell thicknesses of 3km and 30km. We observe mostly linear trends for density and p- and s-wave velocities with respect to depth. Assuming a colder surface temperature of 50K introduces an inversion curve near the surface for density, indicating that temperature affects the models more than pressure. We also experimentally investigate the phase diagram of NaCl-water solutions up to 20% NaCl by weight. By measuring the freezing temperatures of these solutions at varying pressures (0MPa-80MPa), we find that increasing both the salt concentration and pressure decreases the freezing point. We expect that adding NaCl to the pure-water models would flatten the linear trends. Future work includes further comparisons between the models and saltwater experiments, exploring the phase diagram of different solutes (e.g., MgSO4), and extending the models through Europa’s subsurface ocean layer. [Preview Abstract] |
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A01.00120: LaACES Ballooning Research Ayana Smith The use of an Arduino Mega controller in order to measure temperature and pressure of a specific environment is seen to be very efficient. A code was written for the Arduino to gather information that can be applied to read the atmospheric pressure and temperature. The first part of this study was to investigate the relationship between frequency and temperature by constructing and calibrating a Skeetersat with a temperature sensor attached that outputs an audible beeping sound. Each beep had a correlating frequency that could be read to further determine their relationship. The application of this information was to use that same calibration method while incorporating the programming aspect of the Arduino. A series of calibrations were done in order to show how the Arduino with a GPS attachment could be used to produce data of a larger scale to satisfy the goal of developing a payload. The payload will read the pressure, temperature, carbon dioxide and humidity once it is sent into the atmosphere via a balloon launch. The data configured so far will be applied to the payload as the same type of temperature and pressure sensor will be used. [Preview Abstract] |
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A01.00121: The Evolution of the Orbital Period in the Black Hole Binary Star System GRO J1655-40 Anavi Uppal, Charles Bailyn, Georgios Vasilopoulos Binary black hole systems consist of a star closely orbiting a black hole. The intense gravity of the black hole pulls material from the star into an accretion disk. When a particularly large amount of mass is pulled into the disk, the system goes into an outburst, and becomes very bright in x-ray wavelengths. This movement of mass is expected to cause a change in the orbital period of the system. It’s believed that these systems could be the precursors for black hole mergers (observed by LIGO), and monitoring these orbital changes could give insight into how they evolve toward their eventual merger. We analyzed optical data spanning twenty years from the system GRO J1655-40. The pre-outburst period of this system was 2.62191 $\pm$ 0.00020 days. Using phase dispersion minimization, we calculated the post-outburst period of the system to be 2.621925 $\pm$ 0.000014 days. Due to the relatively large error on the pre-outburst period, we currently have only upper limits on any period change. However, additional pre-outburst data is available, and there is significant infrared data from throughout the time span that has not yet been incorporated into our measurement. We hope to refine these values further to measure, or put more significant limits on, the possible period change. [Preview Abstract] |
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A01.00122: A survey of nuclear pasta characterization using alpha shapes Diana Carrasco-Rojas, Dmitriy Morozov, Jorge Lopez Nuclear pastas are speculated to be the densest material found on the universe, approximately 10 billion times stronger than steel. These can be found in the core of a neutron star, which are resultant from the death of a massive star. Up to date, there is no good way to characterize nuclear pastas; furthermore, knowing the type of pasta formed in the crust of a neutron star is an important factor when understanding starquakes, pulsar frequencies and neutron star evolution. This research project explored the possibility of using alpha shapes to characterize nuclear pastas between their different types. Molecular dynamic simulations, where only neutrons and protons were considered, and not the electron gas interaction, were the base of this study. The initial conditions chosen were temperature of 4MeV and 4000 nucleons (2000 protons and 2000 neutrons). As it is known that pastas can exist at low temperatures and sub-saturation densities, simulations were made for all possible combinations of final temperature from 0.01 to 1 MeV and densities from 0.02 to 0.2 fm\textasciicircum 3. Pastas were found to exist around densities of 0.02 and 0.08 fm\textasciicircum 3 in temperatures from 0.01 to 1 MeV. Moreover, the types spaghetti, lasagna, and gnocchi were able to be characterized. [Preview Abstract] |
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A01.00123: Variable Star Studies at Thomas More Observatory Ash Coleman, Lindsay Dawson, Wesley Ryle The goal of these projects is to focus on variable stars, including pulsating variables and eclipsing binaries. In both cases, the stars can fluctuate in brightness over periods ranging from hours to weeks. A series of identified variable targets have been observed at the Thomas More Observatory, and data has been taken across different segments of the period for each target. The images taken have been analyzed for the change in brightness, and the period at each set of images has been calculated. The data for the brightness of each target has been compiled into a single graph revealing the shape of its light curve. This research is still ongoing, with more targets that will be observed over the next few months. [Preview Abstract] |
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A01.00124: Old Star Clusters in Young Galaxies Rachel Pauline, Zion Thomas, Rupali Chandar, William Berschback The PHANGS-HST project is studying thirty-eight massive spiral galaxies in the nearby universe, using data taken by the Hubble Space Telescope. Each galaxy has been imaged in 5 filters, from the near ultraviolet through the red portion of the visible window. The collaboration has developed methods to select stellar clusters based on their appearance, to discriminate them from the numerous individual stars, background galaxies, and other non-cluster objects. These clusters span a wide range of ages, from clusters which formed quite recently (in the last million years) through the oldest known objects in the universe, ancient globular clusters with ages around 12 billion years. We are using these cluster catalogs to select and study the globular cluster populations using automated cuts in colors followed by visual inspection to identify remaining contaminants, such as spherical background galaxies and reddened young clusters. Our globular cluster catalogs are the most comprehensive and homogeneous ones created in spiral galaxies to date. They will provide important insight into the properties of ancient clusters, such as their color (metallicity) and luminosity (mass) distributions, and how these correlate with properties of their parent spiral galaxies. [Preview Abstract] |
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A01.00125: Finding Extremely High-Velocity Outflows in Sloan Digital Sky Survey Data Release 16 Quasars Wendy Garcia Naranjo, Mikel Charles Quasars are the most luminous of active galactic nuclei (AGN), because of this we can study them at high redshifts to gain more insight of galactic evolution within our own universe. Here we present a survey extremely-high-velocity outflow (EHVOs) quasars. These are quasars whose outflows move towards us at 10{\%} - 20{\%} the speed of light. Our research group designed a series of Python modules to automate the search for EHVO quasars. Using data from the quasar catalog of the sixteenth data release (DR16Q) from the Sloan Digital Sky Survey (SDSS), we take a parent sample, normalize the spectra, search for absorption, and then confirm the presence of EHVOs through visual inspection. We are in the process of compiling the largest catalog of EHVOs to date and preparing our code for public release. [Preview Abstract] |
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A01.00126: Using Citizen Science to Collect Data on the Color of Yellowballs Makenzie Stapley, Katie Devine, Charles Kerton, Grace Wolf-Chase Yellowballs (YBs) are a possible new tracer of star formation, and they have the potential to expand astronomers' knowledge. YBs appear yellow in mid-infrared images which assign green to 8 $\mu $m and red to 24 $\mu $m emission, such that overlapping areas appear yellow. This usually indicates a source of ionizing radiation and heat, e.g., a newly forming star. This project strives to create a catalog of YB properties. I focused on gathering data related to the color, which requires measuring the amount of light each YB gives off at different wavelengths. To achieve this, we must distinguish YBs from other light sources in images, a challenging process due to the confusing region. I developed a Python program that allows a user to draw a polygon around the YB and separate it from its surroundings. This process is labor-intensive, so I adapted this tool to be easily used by anyone, regardless of experience, to allow for the use of citizen science. This tool, along with a user manual and student activity guide, will be available for instructors to use, giving students first-hand experience with research, and the opportunity to donate their data to our project. We hope this project will help us create our catalog and expand our knowledge. [Preview Abstract] |
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A01.00127: Searching for Cosmic Strings using SPT-3G Data Ebtihal Abdelziz The high-precision measurements of the cosmic microwave background anisotropy we have today match the predictions given by the $\Lambda$CDM model. This data constrains the parameters defined by the Standard Model of cosmology tightly. Another interesting parameter to constrain is that of the cosmic strings. Strings are linear topological defects, remnants of inflationary-era physics that persist after the big bang. They are formed in a variety of models of inflation. In 2013, the Planck Collaboration released its constraints on the string parameter. SPT-3G has higher sensitivity to lower angular scales (the region where cosmic strings reside) and B-mode polarization measurements. These advantages SPT-3G can show that tighter constraints on the string parameter can be placed compared to Planck. [Preview Abstract] |
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A01.00128: Modeling of Dwarf Galaxies Containing Wide Binary Stars Katharine Lee, Matthew Walker Detection of wide binary stars in dwarf galaxies is a new method for determining the nature of sub-galactic dark matter structure. Because the gravitational force between the stars in a wide binary pair would be comparatively very weak and susceptible to disruption due to dark matter halo substructures, detection could potentially invalidate the cold dark matter paradigm. The standard method to search for wide binaries is the two-point correlation function, which quantitatively measures clustering within a galaxy. In accordance with this, we model sample dwarf galaxies based on the Plummer density profile with binary pairs added based on a normal distribution in order to detect potential wide binaries. The goal of the creation of this model is to bolster the analytic framework by which the separation function can be used to accurately identify real systems with wide binaries. We show that the distribution of nearest neighbor distances in a model containing binary stars has statistically significant differences when compared to the model without binaries. [Preview Abstract] |
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A01.00129: IceTray UHE Neutrino Reconstructions Analysis. Jessica Kienbaum, Brian Clark The IceCube Neutrino Observatory is a cubic kilometer hexagonal lattice deployed at the South Pole comprised of photomultiplier tubes to detect Cherenkov light from neutrino-nucleon interactions in the ice. Methods of ultra-high energy (UHE) event reconstruction used by IceCube remain key components in pointing to possible neutrino sources in extremely distant parts of the universe. In this study,~high performance distributed cluster computing using SLURM and~Monte Carlo simulated neutrino and muon events were used in the analysis of Ophelia and LineFit reconstruction techniques. Cuts were applied to select for bright, charge-current interaction events. Error analysis and energy dependence comparisons showed that Ophelia and LineFit have comparable accuracies for UHE neutrino reconstructions, and it was demonstrated that~new reconstruction algorithms can be used that are better supported and more robust. [Preview Abstract] |
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A01.00130: Estimating the Age and Ambient Medium Density of SNR 0509-67.5 Using Self-Similarity Zoe Rosenberg, Prasiddha Arunachalam, John P. Hughes Self-similarity is a methodology which describes exactly or approximately similar objects. It naturally occurs both on Earth and in outer space, and has wide applications in astrophysics. Self-similarity is an important aspect being used to study Type Ia supernova remnants (SNRs), since we can assume they are approximately self-similar as they expand into the ambient medium as a function of time within certain stages of their evolution. SNRs are self-similar because their internal structure remains approximately the same over time. When a remnant is self-similar, it is possible to use similarity solutions to determine quantities that would be much more difficult to determine otherwise. Using similarity solutions from Table 7 of the Truelove and McKee study in 1999, along with specific values of the mass of the explosion and the explosion energy, we estimate values of the age and ambient medium density for 0509-67.5, a Type Ia SNR residing in the Large Magellanic Cloud. [Preview Abstract] |
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A01.00131: Photometric Study Of RR Lyrae Star TV Lyn SheKayla Love, Susmita Hazra In this research, we are reporting the light curve of RR Lyrae type variable star TV Lyn. This star is observed in the northern hemisphere and its coordinates are 07:33:31.7 +47:48:09.8. We have used data from Las Cumbres Observatory (LCO) which consists of a worldwide network of robotic telescopes. Photometric measurements were conducted using the SBIG 6303 0.4-meter telescope with a field of view of 29’ x19’. Depending on what the color of a star is when different filters are applied to it, the luminosity will change accordingly. Our data consists of four filters, Bessell B (Blue), Bessell V (visual), SDSS-I (Infrared), and PAN-STARRS-Z (Near Infrared). Results show that this star has a variability period of 0.2407±0.002 days, metallicity -1.49, and located at a distance of 1362±118 pc. We have used estimate of the reddening E(B-V) = 0.08. This research is a part an Our Solar Sibling Project by an undergraduate student with the help of a faculty advisor and an Our Solar Project Investigator. [Preview Abstract] |
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A01.00132: Searching for the remnants of the smallest, oldest, faintest galaxies accreted by the Milky Way Hillary Diane Andales, Kaley Brauer, Alexander Ji, Anna Frebel The Milky Way (MW) grows by merging with or accreting other galaxies. Still, not much is known about how low-mass galaxies---the smallest, oldest, and faintest of which being the ultra-faint dwarfs (UFDs)---assembled to form the MW. To fill this gap, we search for UFD remnants in the outskirts (``stellar halo'') of the MW using the kinematics of halo stars. Because the kinematics of halo stars retain information about their accretion origins, a cluster of halo stars in kinematic phase space may be the remnant of a progenitor UFD. However, the strength of this cluster-remnant correspondence is uncertain. To investigate this correspondence, we use 22 Milky Way-like halos from the Caterpillar simulations. We find that, among six clustering algorithms, HDBSCAN performs best at identifying true remnants. For UFD-mass remnants within 5 kpc (50 kpc) of the Sun, 17.81{\%} (5.46{\%}) of HDBSCAN clusters are true remnants. We also find that, compared to the median of all remnants, the recovered remnants have more recent accretion times, distinctively higher energy (2.5x), velocity (2.0x), angular momentum L$_{z}$ (13.5x), J$_{r}$~(11.1x) and J$_{z}$~(6.3x). Ultimately, these results help inform the use of Gaia kinematics data in uncovering the formation history of the MW. [Preview Abstract] |
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A01.00133: The Weak S-Process in Massive Stars Xinyan Xiang The weak $s-$process occurs in massive stars with $M \geq 8 M_{\odot}$ during convective core He burning and shell C burning, and synthesizes stable isotopes up to a mass of A $\approx$ 100. Computing the weak $s$ contributions to the solar abundances is more sensitive to cross-section uncertainties compared to the main component, and previous stellar models have difficulty obtaining the needed weak $s$-only isotopic abundances without also overproducing others. In this work, we calculate the weak component of the $s$-process. The weak $s$ solar abundances are taken as residuals from previous computations for the main $s$ component. To investigate possible differences in neutron exposures between both the main and weak components and the He-core and C-shell sites within the weak component itself, we complete the calculations using different neutron exposure distribution models: a linear combination of exponential distributions, a superposition of exponential distributions, a Gaussian distribution, and a Planck distribution. The solutions to the differential equation are assessed by tuning the fraction $f$ of $^{56}{Fe}$ seed nuclei and characteristic neutron exposure $\tau_{0}$ as fit parameters. [Preview Abstract] |
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A01.00134: COLOR OF THE FUTURE COSMOS: DETERMINING THE SPECTRA AND INTENSITIES OF THE UNIVERSE'S ENERGY BACKGROUND OVER TIME Trinity Taylor, Katie Mack The Universe's radiation has evolved since the Big Bang and could change how our future looks. The radiation we now use to observe the sky may not be accessible later; galaxies and the Cosmic Microwave Background (CMB) may not be detectable in 100 billion years. I am determining what types of energy will dominate the Universe in the future by programming four mathematical models of the change in radiation from stars, the CMB, dark matter (DM), and Hawking radiation (HR) over time. Because I am examining theoretical sources of radiation, I'm using standard assumptions. For DM, I assume particles can annihilate one another to produce energy. Annihilation rates would increase as DM clusters together due to gravity, but universal expansion will slow the process. HR causes black holes to lose mass, but noticeable differences would be seen after a long time when black hole accretion stops. As stars burn out, HR and DM annihilation rates will continue increasing. The CMB, residual radiation from the Big Bang, loses energy as the Universe continues to expand until it becomes barely detectable. Based on these four trends, I hypothesize that HR will be the most dominant in the far future, DM annihilation second, starlight third, and CMB radiation being the least dominant. [Preview Abstract] |
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A01.00135: Preliminary studies on a search for Higgs boson pair production in association with a top quark-antiquark pair Jade Chismar, Samuel May, Indara Suarez We present preliminary studies on a search for Higgs boson pair production in association with a top quark-antiquark pair (ttHH), a process which has not yet been searched for at the LHC. In the Standard Model (SM), ttHH has a very small cross section of 0.775 fb at a center-of-mass energy of 13 TeV, however, this could be modified by a variety of theories of physics beyond the SM (BSM). Among these theories are type-II Two Higgs Doublet Models, where a ttHH final state may result from heavy Higgs boson production in association with a top quark-antiquark pair and subsequent decay of the heavy Higgs boson into two SM Higgs bosons, and Composite Higgs Models, where a ttHH final state may result from pair production of vector-like top partners (T) with subsequent T $\to $ tH decays. ttHH rates may also be modified by BSM couplings, like the ttHH contact interaction. We target ttHH events in which one H decays to two photons, and the other H decays to a pair of bottom quarks, tau leptons, or W bosons. One of the most challenging backgrounds in the diphoton final state is single Higgs boson production in association with a top quark-antiquark pair (ttH). This poster presents the results of studies to reduce the ttH contamination in a search for ttHH. [Preview Abstract] |
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A01.00136: Searching for Hidden Matter with milliQan Emily Pottebaum A growing number of searches for dark matter are looking for evidence of physics beyond the Standard Model. Of particular interest is the proposed milli-charged particle (mCP), which the milliQan experiment will search for during Run 3 of the LHC. The novel design of the milliQan detector is expected to substantially extend the mass-charge parameter space of mCPs, covering previously unexplored territory in experimental particle physics. This talk will discuss the development of a summing amplifier designed to significantly improve the milliQan detector's charge sensitivity. [Preview Abstract] |
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A01.00137: Searching for Strangeness Enhancement in Ultra-Peripheral Pb$+$Pb Collisions with ATLAS Morgan Knuesel Quark-gluon plasma is an exotic state of matter which can be produced in high-energy heavy ion collisions. The saturation of strange quarks in these collisions is considered one of the signatures of QGP formation and thus is a useful tool for studying various collision systems. In an effort to push the bounds of where evidence of QGP is found, this study investigates the feasibility of measuring strange hadrons in photonuclear ultra-peripheral collisions using 5.02 TeV Pb$+$Pb collision data collected by the ATLAS experiment at CERN's Large Hadron Collider. Motivation for this study arrives from recent findings of collective phenomena similar to that of a QGP in these collisions, as well as evidence of strangeness enhancement in smaller systems such as proton-proton collisions. [Preview Abstract] |
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A01.00138: Studying the Stability of Pulse Shape Analysis in The Majorana Demonstrator Neutrinoless Double Beta Decay Experiment Jennifer James The Majorana Demonstrator is an array of germanium detectors built to search for neutrinoless double beta decay of 76Ge. The experimental sensitivity is improved by application of pulse shape analysis (PSA) to identify and reject key backgrounds. One of these, targeting multisite gamma background event topologies, is based on the sharpness of the rising edge of the signal pulse. This project focuses on the stability of this multisite PSA, characterizing the drift of the PSA metric observed in calibration data. The impact of the stability on the signal efficiency and background rejection is studied. [Preview Abstract] |
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A01.00139: Stratospheric Neutron Detection Using Personal Neutron Dosimeters Anisa Tapper High Altitude Balloon flights provide a platform for measuring galactic cosmic ray interactions in the Regener-Pfotzer maximum (R-P max 15-25 km) where ionizing particle count rate reaches an apex. The flux of secondary galactic cosmic ray (GCR) particles, such as, pions, muons, electrons, positrons, photons; depends on altitude, latitude, solar activity, and atmospheric composition.~ Through interactions, these particles undergo energy loss and decay while traveling through the atmosphere; neutrons are a part of the secondary interaction.~ Flux and fluence measurements allow for the categorization of particles from GCR interactions to determine the number of neutrons relating to the R-P max range.~ It is hypothesized that neutrons are generated in the upper atmosphere due to collisions between the GCR and nuclei of atmospheric oxygen and nitrogen, causing the nuclei to break into atomic and subatomic particles and cause higher numbers of neutrons to occur lower in altitude. An investigation was conducted using a personal neutron dosimeter, paired with a digital camera and Geiger-M\"{u}ller omnidirectional counter to establish a correlation between neutron counts and the altitude of charged particle maxima.~ A minority of neutrons detected passed through the dosimeter at higher altitudes than the measured R-P maxima, confirming the hypothesis. A greater occurrence of neutrons appeared at or below the main interaction layer in the upper atmosphere showing the importance of having charged and neutral detectors used in conjunction with each other to better understand the dynamics of the charged and uncharged particles in the atmospheric environment. [Preview Abstract] |
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A01.00140: Gaussian Process vs. Log Gaussian Cox Process: Comparing Methods for High Energy Physics Data Pavani Jairam, Rachel Hyneman, Michael Kagan High energy physics (HEP) data from particle colliders are studied using statistical methods to compare the data we observe with what we expect. HEP collider data is often arranged into histograms of counts of the number of events observed with a given feature value which can be modeled with the Poisson distribution. In many analyses, the signal appears as a localized excess on top of a smooth background that must be modeled to observe a signal. For this project, we use toy data that mimics the falling exponential behavior of HEP data. An effective method for modeling smooth backgrounds in HEP data are Gaussian processes. Nonetheless, this method requires data to be binned, which loses information. Gaussian processes generally yield meaningful uncertainties, but it fails to capture the Poissonian uncertainties of HEP data. The log Gaussian Cox process is a novel method we expect to improve on those shortcomings. We compare the ability of the Gaussian process and the log Gaussian Cox process to reproduce a known intensity function when modeling the smooth background events. We find that the log Gaussian Cox process is promising, however, further exploration is needed to create an optimal model and develop a deeper understanding of the log Gaussian Cox process. [Preview Abstract] |
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A01.00141: CP-Violation in the Top-Higgs Interaction at Future Muon Colliders Morgan Cassidy, Yanzhe Zhang, Ian Lewis, Kyoungchul Kong, Ya-Juan Zheng, Zhongtian Dong The Standard Model (SM) of Particle Physics has been very successful in explaining most observed phenomenologies. However, it cannot explain the observations of dark matter, matter-antimatter asymmetry, etc. Our project focuses on proposing a search for a new source of CP Violation in the top-Higgs interaction at a future muon collider to better understand matter-antimatter asymmetry. Simulations of $\mu^+\mu^-$ collisions are done in both the SM ($\alpha = 0$) and with a CP-violating phase ($\alpha \neq 0$) through Madgraph5\_aMC@NLO, a Monte Carlo simulation framework for event generation and analysis. We present the varying cross-sections for different CP values and kinematic distributions for an $\alpha \neq 0$ case and show corresponding signal-to-background significance calculated for collisions at 1 TeV, 10 TeV, and 30 TeV. We incorporate the detector effects in various kinematic distributions to better simulate the collider environment. Further studies will be done on other CP phases to investigate the sensitivity of observing a CP-violating phase at the muon collider. [Preview Abstract] |
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A01.00142: Development of Charm Identification Technique for Higgs-charm Coupling Talia Saarinen The Higgs boson was discovered by the ATLAS and CMS experiments at CERN in 2012, but properties of Higgs-charm coupling remain unprobed due to the rarity of this decay mode and the difficulty of identifying charm quarks in such events. The goal of this project is to improve upon previous methods of identifying or "tagging" tracks resulting from the decay of charm quarks. We analyze simulated top quark pair data from the ATLAS experiment to evaluate the effectiveness of track variables in distinguishing charm decays from background and other decay modes. 19 of the 24 track-associated variables evaluated were determined to be effective in distinguishing tracks resulting from Higgs-charm coupling. [Preview Abstract] |
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A01.00143: Validating the Muon Endcap Chamber 0 Segment Finder (ME0SF) with Cocotb Chloe Grubb, Andrew Peck, Indara Suarez As part of the 2026 HL-LHC upgrade, the CMS group has planned to enhance its muon system with an introduction of new detector technology using Gas Electron Multipliers (GEM). The Muon Endcap Chamber 0 (ME0) is a 6-layered GEM detector which uses gases and a high voltage electric field to detect ionizing muons. It serves as the first muon detecting station outwards of the CMS interaction point. The ME0 will work with the Cathode Strip Chamber, GEM, and Resistive Plate Chamber systems to back up their muon data for track finding purposes. The ME0 will also work to increase the existing muon system coverage to include the pseudorapidity window, 2.4 \textless \textbar $\eta $\textbar \textless 2.8. The ME0 Segment Finder is an algorithm purposed for the detection of multi-layered patterns of hits in a ME0 chamber. It is implemented in the firmware of a Field Programmable Gate Array. My work with cocotb, a python environment for hardware simulation, focuses on validating these firmware designs through a series of testbenches, Monte Carlo data generators, and software emulators of the firmware algorithm designs. Using these testbenches, we have been able to debug and validate the performance of the firmware in simulation. [Preview Abstract] |
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A01.00144: Making astroparticle and cosmological data easily accessible for education Gabriella Tamayo, Matthew Bellis Since 2014, Siena College faculty and students have put together and maintained the website Particle Physics Playground (PPP), a site that provides simplified particle physics data for outreach and education. In the summer of 2020 it was decided to expand the website beyond particle physics to explore both particle astrophysics and astronomy. The IceCube Neutrino Observatory, in Antarctica, has released a small sample of their data for public use. The Sloan Digital Sky Survey (SDSS), provides large amounts of galaxy data that was used to introduce astronomy to the website and spark the interest of young and aspiring astronomers. The PPP website is also a place for high school and undergraduate students who have some exposure to, or willingness to learn, python. We utilized Plotly to create interactive 3D plots as a way to explain these experiments and observations by demonstrating how others can use these tools to create their own visualizations. The current status of these tools and tutorials will be presented. [Preview Abstract] |
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A01.00145: The use of CEvNS to monitor spent nuclear fuel Caroline von Raesfeld, Patrick Huber With a growing demand for a clean energy supply along with concerns over effective nuclear waste storage, it is imperative to be able to monitor highly radioactive waste in a safe and effective way. To date, no effective technology exists to re-verify the content of Spent Nuclear Fuel (SNF) in a dry storage cask should this become necessary. For this purpose we explore the applicability of using Coherent-Elastic Neutrino-Nucleus Scattering (CEvNS) to monitor the content of SNF in dry storage casks, as SNF produces neutrinos chiefly from $^{90}$Sr decays. We compare these results with what can be achieved via Inverse Beta Decay (IBD), demonstrating that at low nuclear recoil energies CEvNS event rates exceed the IBD event rates by 2-3 orders of magnitude for a given detector mass. We find that 10 kg argon or germanium detectors 3 meters from a fuel cask can detect over 100 events per year if sub-100 eV recoil energy thresholds can be achieved. Backgrounds from cosmic ray neutrons are estimated and considered in a preliminary analysis to examine with what certainty the fuel content in a dry storage cask can be verified. [Preview Abstract] |
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A01.00146: Constraining the Space of Standard Model Effective Field Theory Using Geometric Methods Valerie Wu, Yuchen Yang, Shuangyong Zhou, Cen Zhang Standard Model Effective Field Theory(SMEFT) is an approach to search for Physics beyond the Standard Model. This project focuses on constraining the parameter space of dimension-8 operator coefficients in SMEFT, since their experimental effects are important in determining UV-completeness. The parameter space of the dim-8 operator is a convex cone dual to a spectrahedron. Finding the boundaries of this convex cone is equivalent to finding the extremal ray(ER) of its dual spectrahedron. Previous research has found the analytic solution to the ER of this spectrahedron for small degrees of freedom (n$=$2, 3). The present work aims to find the analytic solution for larger degrees of freedom. Numerical methods were developed to find ER for larger n. From the numerical solutions, we proposed conjectures for general analytic solutions. The conjectures for n$=$4 and rank $=$ 2 have been proved thoroughly, and several other cases, such as n$=$5, 6 and rank $=$ 3 have been understood by extending the ideas from the proofs. Present analysis suggests that a general analytic solution for all n is not promising. Current and future work consists in investigating special cases with more physical relevance. [Preview Abstract] |
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A01.00147: Study of Particle Interactions in Quantum Systems Kya Wiggins Quantum mechanical systems are characterized by their energy eigenvalues.~Previous~studies have shown that the distribution of spacings between adjacent energy eigenvalues is related to the dynamics in the classical version of the system.~Systems with regular dynamics have eigenvalue spacings~that follow the Poisson distribution, while systems with chaotic dynamics have spacings that~follow the Gaussian Orthogonal Ensemble~(GOE)~distribution.~ The goal of my research was to find a very simple quantum system that exhibits a transition from Poisson to GOE statistics, even though the classical dynamics doesn't clearly change from regular to chaotic.~I investigated the eigenvalue spacings in a system of~1 to 9 Dirac delta barriers placed in an infinite square well such that the ratio of the interval lengths between the barriers was irrational. I computed 1,000~energy eigenvalues of the sequence at three energy ranges: low~energy (the probability~that a particle is transmitted~through a delta barrier is close to zero), medium energy (the transmission probability~is~close to one half), and high energy (the~transmission probability~is~close to one).~I then unfolded the sequence, so that the average eigenvalue spacing was one, and~found the distribution of spacings.~For~six or more barriers~the low energy sequences followed~Poisson statistics, the medium energy sequences followed~GOE statistics, and~high energy sequences showed~Gaussian statistics peaked at one.~These results are interesting because this is~a very simple~system,~but~increasing the transmission probability shifts the statistics from Poisson to~GOE~to Gaussian.~ ~ [Preview Abstract] |
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A01.00148: A New Reaction Plane Detector for ATLAS Heavy Ion Physics Program in Run 3 Farah Mohammed Rafee The ATLAS Zero Degree Calorimeter (ZDC) is installed in the Target Absorber for Neutrals of the Large Hadron Collider (LHC) during the Heavy Ion data taking. Each of the two ATLAS ZDCs comprises one electromagnetic (EM) and three hadronic (HAD) modules. By measuring the energy deposited by spectator neutrons, the ZDC can determine the spectators’ multiplicity and therefore the event’s centrality. The University of Illinois at Urbana-Champaign (UIUC) is developing and constructing a new Reaction Plane Detector (RPD) to be installed downstream of the ZDC EM module in Run 3. The RPD will map the transverse profile of the spectators’ shower, which is directly related to the reaction plane that characterizes each collision. The detector consists of 256 fused silica core optical fibers, grouped into 16 channels. The fibers have four different lengths and are arranged according to a periodic staggered pattern, developed to be paired to a machine learning-based reconstruction algorithm. In this contribution, we present the design of the RPD prototype, built at UIUC for the 2021 test beam at the CERN North Area, and the final design for Run 3. Details about the fused silica fibers’ properties and the photomultiplier tubes will also be discussed. [Preview Abstract] |
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A01.00149: Simulated-based Anomaly Detection for Multileptons at the LHC Katarzyna Krzyzanska, Benjamin Nachman Decays of Higgs boson-like particles into multileptons is a well-motivated process for investigating physics beyond the Standard Model (SM). A unique feature of this final state is the precision with which the SM is known. As a result, simulations are used directly to estimate the background. Current searches consider specific models and typically focus on those with a single free parameter to simplify the analysis and interpretation. In this presentation, we explore recent proposals for signal model agnostic searches using machine learning in the multilepton final state. These tools can be used to simultaneously search for many models, some of which have no dedicated search at the Large Hadron Collider. [Preview Abstract] |
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A01.00150: Performance Studies for IceCube-Gen2 Optical Sensors Delaney Butterfield A new Cherenkov photon sensor, the Long Optical Module (LOM), is under development for IceCube-Gen2, the proposed expansion to the IceCube South Pole Neutrino Observatory. There are two types of LOMs in development: the LOM16 and LOM18. Our studies concentrate on the LOM16, which is made of 16 4'' Photomultiplier Tubes (PMTs) in a glass vessel, distributed uniformly to increase photon detection rate by a factor of 3 compared to the existing modules. The new modules have conical gel pads that interface the PMT sensors to the glass vessel, and will increase module sensitivity and collection efficiency. Part of this enhancement is due to the total internal reflection on the conical side of the gel pads, which helps capture photons which may not have been aimed at the PMT. The alignment of the PMTs and opening angles of the gel pads are crucial to maximizing the photon capture rate. In order to investigate the photon acceptance of the LOM16 module, we generated a ray-trace simulation using Geant4 and calculated the angular acceptance of each PMT in the module to further optimize geometry and PMT alignment. We will provide an overview of the results of our simulations, as well as our design implementation. Prototypes of the modules will be installed and tested in the IceCube Upgrade. [Preview Abstract] |
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A01.00151: Examining the relationships between charged-particle spectra and event centrality in oxygen-oxygen collisions using the STAR detector at RHIC Jordan Cory High energy collisions of heavy ions form a relativistic hydrodynamic fluid called the Quark Gluon Plasma (QGP). Central collisions, collisions that have a small impact parameter, produce larger volumes of QGP than peripheral collisions with a larger impact parameter. One way of studying the QGP is by comparing the momentum spectra of charged particles in central and peripheral collisions. Traditionally at the Solenoidal Tracker at RHIC (STAR) experiment, centrality is determined via charged particles at mid-rapidity within the Time Projection Chamber (TPC). This measure of centrality could suffer from auto-correlation if the charged-particle spectra are measured in the same phase space. To mitigate this effect, centrality can also be estimated using the charged-particle multiplicity measured in the Event Plane Detector (EPD), covering a pseudorapdity range of $2.1 < \lvert\eta\rvert < 5.1$. This poster will compare the charged-particle momentum distribution ratios obtained by using the two different methods of estimating collision centrality in oxygen-oxygen collisions at a center-of-mass collision energy of 200 GeV per nucleon pair. Such a comparison will help us explore the inherent correlations between particle production across different regions of a heavy ion collision. [Preview Abstract] |
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A01.00152: Measuring the Muon Neutrino Cross Section Using Earth Absorption Natalie Jones The IceCube Neutrino Observatory has observed neutrinos with energies up to 10 PeV. High-energy neutrinos may be absorbed by the Earth during deep inelastic scattering (DIS) with nuclei. This creates a deficit in Earth-transiting neutrinos, which can be detected by IceCube. Earth's absorption of neutrinos at high energies can therefore be used to determine the neutrino-nucleon cross section as a multiple of the Standard Model value. A current analysis attempts to measure the muon neutrino cross section using 8 years of data and a maximum likelihood fit for the transmission rate of through-going muon neutrinos. Studies on systematic uncertainties are important. In particular, studies on the atmospheric and astrophysical neutrino fluxes have shown that the cross section depends on assumptions about these fluxes.?[U+2028]The ongoing analysis could have important ramifications. Through investigation of systematic uncertainties, IceCube will produce one of the most accurate neutrino-nucleon cross section measurements to date. An unexpected cross-section could indicate beyond-the-standard-model physics. [Preview Abstract] |
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A01.00153: Magnetic Shielding Design and Optimization for NuDot Sarah Vickers NuDot is the most recent prototype in the development of background reducing methods for neutrinoless double-beta decay. The aim is to be able to identify the direction of electrons moving through the scintillator fluid from the timing of Cherenkov light. The experiment is a half-ton prototype which contains a sphere of 210 8" and 2" photo-multiplier tubes to detect the decay events within the sphere. Each of these PMTs are sensitive to the presence of any magnetic field, including that of the Earth. This past summer, I worked to design a set of electromagnets to cancel out the components of the Earth's Magnetic field (EMF) to ensure optimal performance of the PMTs. A set of two coils will make this possible, one horizontal and one vertical. Each is a different coil design, the vertical being a variably-pitched solenoid and the horizontal a set of two square Helmholtz coils. Together, they reduce the overall magnetic field to below the 0.1 EMF threshold at which the PMTs will operate at 99% accuracy or higher. Here I will present magnetic field simulations, CAD designs and a proposed circuit diagram to give a comprehensive overview of my work and its incorporation into the greater NuDot experiment. [Preview Abstract] |
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A01.00154: Physics Outreach Manual for K-12 STEM Students Janelle Valdez, Quinn Wilson, Hanna Terletska Despite many efforts, women and racial and ethnic minority students continue to be underrepresented in physics. In addition to various programs and efforts, the outreach activities are recognized to be beneficial to engage K-12 students in STEM. Outreach programs can create excitement and interest in science with students and the public, increase appreciation in the physics community, and serve as an excellent tool to build university-community relationships. In this project, we designed the physics outreach manual for K-12 students. Teachers, students, and professors can benefit from this manual. The manual contains a description of the experiments, a supply list and cost, pictures, and the accompanying videos. The outreach experiments cover different areas of physics, including mechanics, electricity and magnetism, and optics. Our focus was on designing a set of experiments that have been tested on outreach events by our WIP group. The videos for each experiment help with clarifying the experimental set-up for both the presenter and the student, making it easier to know how to present new ideas to students. With the completion of this project, our outreach manual will be freely available through the MTSU WIP Website to the public. [Preview Abstract] |
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A01.00155: Accuracy of an iPhone 12's Accelerometer on Five- and Fifteen-Degree Inclines Erin Schriever Access to tools for taking scientific measurements in high school classrooms is important. New and sometimes hard to grasp concepts are easier for students to understand when a demonstration or lab activity can be completed. Smartphones contain sensors that can provide these tools for a lower cost to classroom settings. When considering use of a specific sensor, something to acknowledge is how accurately it takes measurements. In this experiment, the accelerometer in an iPhone12 and a PASCO Scientific Wireless Accelerometer/Altimeter (PS-3223) were compared. To do this, both were attached to a dynamics cart and sent down an incline of five- and fifteen-degrees to compare measurements of constant acceleration. When comparing the data, a discrepancy was found. Measurements from the fifteen-degree incline were consistent across the devices, however measurements from the five-degree incline were not. The data from the five-degree incline showed the acceleration of the iPhone12 decaying as it went down the ramp. This result indicates that an iPhone12 may not be the most effective replacement to a specialized tool for measuring constant accelerations on small inclines. [Preview Abstract] |
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A01.00156: A redesign and analysis of the PhET Geometric Optics simulation for effective science education Sarah Chang Geometric optics is a confusing subject for many physics students, who often first encounter the subject in introductory college physics classes. Traditional instruction in geometric optics involving lectures and physical laboratories have been shown to be less effective than using interactive, online simulations. In 2004, PhET Interactive Simulations created a geometric optics Flash simulation, but all modern browsers have eliminated support for Flash as of January 2021. In response, we redesigned and redeveloped the simulation from scratch in Javascript/HTML5, adding new features to expand on the learning goals and address common student difficulties found in the literature. We assessed the effectiveness of the redesign through think-aloud student interviews and revised the design of the simulation based on that feedback. A public prototype of the simulation is now available for use and will be a valuable resource in geometric optics curricula around the world. [Preview Abstract] |
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A01.00157: Monitoring the Light Curves of Pulsating White Dwarf Stars for Potential Outbursts Mabel Clausen, Kurtis Williams During this observation, we hoped to obtain data regarding any outbursts from white dwarf stars PG 1541$+$651 or WD J1712-1915. Both stars are currently pulsating and close to the red edge of the ZZ Ceti instability strip, justifying the possibility of outbursts. Unfortunately, no outburst occurred, but evaluation of the data from these nights still took place to help inform others about these rarely acknowledged white dwarfs. In sharing these outcomes, we hope that others can use these data as needed, especially since the values gathered for PG 1541$+$651 have changed significantly within the past 21 years. [Preview Abstract] |
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A01.00158: Implementation of the Tri-Sol System Sydney Coil, Patrick O'Malley, Dan Bardayan The twin solenoid system, also known as Twin-Sol, has been essential in the past for producing unstable beams and subsequently refocusing these beams for analysis. To improve on the system, an addition of a third solenoid has been commissioned, therefore turning Twin-Sol into Tri-Sol. This upgrade to the system was completed and tuned for four discrete energies using an alpha source. The system was then again tuned with two different radioactive beams (RIBs). This RIBs tuning is the first in a group of three tunings for the Tri-Sol system. Upgrading to Tri-Sol will give the capability to study the decay of unstable beam by improving the beam optics and purity. [Preview Abstract] |
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A01.00159: Method Development of MC-LR Detection in the Liver and Brain of the Mummichog Madeline Klumb, Alanna Aga, William Silander, David Hollis, John Wheeler, Sandra Wheeler Microcystins (MCs) are noxious compounds found in cyanobacteria (blue-green aglae) accumulations in freshwater and estuaries. MCs are known to be potent hepatotoxins and neurotoxins. The nervous systems of fish are at high risk of exposure as these toxins are released into the water. We seek to examine whether regional susceptibility to Microcystin-leucine/arginine (MC-LR) exists in the Central Nervous System (CNS) of fish using the mummichog (Fundulus heteroclitus). Regional brain samples will be analyzed via Ultra-High Performance Liquid Chromatography (UPLC). There is little published LCMS data on MCLR and regional brain studies are novel. The topic of this poster is the extraction and UPLC separation method to isolate MC-LR from the tissue of exposed fish and calculate the buildup of the toxin after exposure. [Preview Abstract] |
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A01.00160: Detector Development for the IMPulsive Phase Rapid Energetic Solar Spectrometer (IMPRESS) Collaborative Experiment Misty Chien The IMPulsive Phase Rapid Energetic Solar Spectrometer (IMPRESS) is a CubeSat-based experiment for chracterizing hard X-ray emissions from solar Pares. These solar Pares occur during magnetic reconnection events on the sun’s atmosphere and release an enormous amount of energy in the form of non-thermal accelerating electrons. Previous studies revealed fast time variations in the x-ray Pux, but there were issues of signal pileup and other detector shortcomings (Kiplinger et al 1984; Qiu et al. 2012). IMPRESS seek to further our knowledge in electron acceleration mechanisms by optimizing its detectors for temporal and energy resolution in order to effectively measure hard X-ray Pux from solar Pares. To accomplish this, the satellite implements an array of fast scintillators with silicon photomultiplier read out in conjunction with high-rate electronics and processing systems. Through calibration routines using radioactive sources and varying certain parameters in the data acquisition code, we \nd that we can optimize the detector to approach the desired temporal and energy resolution. Because IMPRESS is a collaborative project across institutions, the experiment offers a multitude of opportunities to involve students of all levels on the development effort. [Preview Abstract] |
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A01.00161: Comparison of the Kitaev-Webb and Klco-Savage Algorithms on IBM Q Systems Aurelia Brook, Dries Sels, Javad Shabani, Andreas Tsantilas Recent advancements in quantum algorithms have been significant, yet there is still much to be done in terms of benchmarking noisy quantum computing hardware. Utilizing IBM’s Qiskit software development kit and quantum hardware, we have streamlined a novel way of benchmarking and characterizing error on noisy qubits. We tested the noise levels of IBM’s quantum hardware by implementing the Kitaev-Webb state preparation algorithm (Kitaev, Webb 2008) and the Klco-Savage (Klco, Savage 2019) algorithm to prepare a 1D discrete Gaussian and a symmetric exponential distribution as a pseudo-Gaussian. Error data is then analyzed using KL divergence to quantify disparities between noiseless simulations and experimental runs on IBM Q processors. Such simulations provide insight into dominant sources of noise on quantum chips, and were subsequently compared to randomized benchmarking in order to evaluate how they compete with industry standard methods. [Preview Abstract] |
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A01.00162: Array Processing of Receiver Functions Across the Southern Alaska Cordillera Using 400 Nodal Seismometers Anneke Avery, Kevin Ward, Jimmy Bradford, Amir Allam, Carl Tape Alaska is comprised of an active subduction zone, accreted terranes, and a complex tectonic history that makes it a unique place to study tectonic processes. In February and March of 2019, we deployed 400 three-component nodal seismometers in Southern Alaska between Anchorage and Fairbanks. 300 nodes were placed 1 km apart in a large pseudo-linear array that crossed the Denali Fault and 100 nodes in a closer subarray to provide greater detail across the Denali Fault. We present the results of our radial receiver function analysis calculated from teleseismic earthquakes to image subsurface structure in the region. We include data from nearby broadband stations to evaluate the robustness of our results obtained from our spatially dense but temporally limited nodal deployment. We explore the possibility that our dense nodal array can image subsurface discontinuities in greater detail than existing broadband stations. In our work, seismic discontinuities are often localized, and the same structure is not regularly seen in receiver functions for different events. Discontinuities from our nodal receiver functions are not as consistent as those observed in the broadband receiver functions. For our deployment, nodal receiver functions do not offer the same level of results as broadband seismometers under equivalent processing techniques. Ongoing work includes array processing by stacking nearby nodal sites before calculating receiver functions to further help reduce noise and enhance scattered wave signals. [Preview Abstract] |
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A01.00163: Beginning Stages of Creating a Bioactive Glass Bead Drug Delivery Patch Marie Sykes Bioactive glass beads are a highly durable material anywhere meant to be completely safe for the human body. The aim of the research is to find a new way to slowly deliver a drug over time in the form of the patch, with the first baseline goal is to create a vitamin patch to deliver a standard dose of vitamins over the course of a week or longer. Over the course of the past semester since we begun research, we have documented various types of such beads and powdered beads to test whether or not they are a suitable candidate for drug delivery through microscopic data, spectroscopic data, and their degradation process in heat. The type of beads we work with are typically anywhere from typically sized ten to three hundred micrometers [Preview Abstract] |
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A01.00164: The Apparent Diameters of the Planets Kaitlyn Kosten \documentclass{article} \usepackage[english]{babel} \usepackage[letterpaper,top=2cm,bottom=2cm,left=3cm,right=3cm,marginparwidth=1.75cm]{geometry} \usepackage{amsmath} \usepackage{graphicx} \usepackage[colorlinks=true, allcolors=blue]{hyperref} \title{The Apparent Diameters of the Planets} \author{Kaitlyn Kosten} \begin{document} \maketitle \begin{abstract} Before the invention of the telescope, astronomers had difficulty determining the apparent sizes of planets visible to the naked eye. While Tycho Brahe, Ptolemy, Al-Farghani, and Al-Battānï measured similar apparent sizes for the five visible planets, Giovanni Magini reported drastically different results. To better understand the difficulty faced by early astronomers, I set out to make my own measurements of the naked eye apparent diameters of Venus, Jupiter, and Saturn. I built an apparatus that mounts on top of a telescope and holds a micrometer. When a planet is viewed through the micrometer, the micrometer setting can be adjusted until its prongs align with the outer edges of the planet’s visible disk. From the micrometer reading and the distance from the observer’s eye to the micrometer, the apparent diameter of the planet (as seen by the naked eye) can be found. Using this apparatus I measured the apparent diamete [Preview Abstract] |
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A01.00165: Measuring Single-Walled Carbon Nanotube Length Using Length Analysis by Nanotube Diffusion Ainsley McDonald-Boyer, Ali Alizadehmojarad, Bruce Weisman The average length of single-walled carbon nanotubes (SWCNT) in a SWCNT dispersion was attempted to be measured using Length Analysis by Nanotube Diffusion (LAND). Due to the fluorescent property of semiconducting nanotubes, the SWCNT's emission can be collected when they are excited with the appropriate wavelength. Using a high-resolution camera as part of an inverse laser microscope apparatus, the movement of individual nanotubes in the sample was captured in the form of videos and images. By analyzing the motion of the nanotubes from the images using specialized software, the diffusion coefficient can be found which allows the length of the nanotubes can be calculated. This work specifically investigated (6,5) nanotubes by using a 973 nm bandpass filter to remove the emission from other species found in the dispersion. [Preview Abstract] |
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A01.00166: Analysis of Passive Acoustic Data at Station ALOHA Cabled Observatory Yuliya Kornikova, James Potemra, Bruce Howe The Station ALOHA Cabled Observatory (ACO) is located in the Central North Pacific Ocean and is an ocean-bottom observatory that monitors ocean processes, including sound, continuously in real-time. The ACO hydrophone records ocean acoustics over a broad scale. This allows for the study of certain elusive marine mammals like baleen whales, who tend to stay in deeper water. The ocean-bottom hydrophone at the ACO is used to record acoustic events such as glass balls shattering, ships passing by, and acoustic behavior of whales in a location that is difficult to study long-term due to its remoteness. We examined 12 months of 24kHz data from the ACO (January 2020- December 2020) and found a variety of sounds, some of which we identified as whale vocalizations. We created spectrograms of the audio files for visualization, analysis, and annotation. We identified sounds produced by minke, humpback, and sperm whales. We found seasonality in humpback and minke whale sounds as they gradually leave in May and return in October. This work is meant to provide an overview of sounds the ACO is recording, and the identified signals can be used as training for machine learning for the development of a sound identification program that would be able to run in real time on the hydrophone. [Preview Abstract] |
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A01.00167: Analyzing the Spectral Characteristics of Propagations Teepees Sydney Wilson, Chuck Higgins, Shing F. Fung, Dave Typinski, Jeremy Faden A high-frequency spectral feature has been previously identified in ground-based spectrographs and recorded by a group of citizen scientists from the Radio JOVE project (Fung et al., 2020 GRL, 47, e2020GL087307; https://doi.org/10.1029/2020GL087307). This feature is a teepee (TP) tent shape found in data between 15 to 30 MHz, where the spectral enhancement frequency increases and then decreases with time, hence the name (Figure 1). The presence of these features is currently being attributed to the ionospheric reflection of VHF emissions from lightning activities in remote thunderstorms. In this study, we will analyze TP observations by studying their times (seasons) of occurrences, duration, apex frequency, upper cutoff frequency drift rates, and quality, to better understand these spectral features. Analysis was completed using the Autoplot software (http://autoplot.org), and these characteristics and statistics are presented in order to gain a deeper understanding of these peculiar spectral features. [Preview Abstract] |
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A01.00168: Measured Octanol/Water Distribution Coefficients and Abraham Summation Hydrogen Bonding Acidities for the Catechol-Flavones Taryn Gibbs, Dr. Lance Whaley Flavonoids are a class of diverse organic molecules present broadly in plants. They are claimed to have a wide range of bioactive effects including anti-cancer, anti-inflammatory, anti-aging, and anti-neurodegenerative properties. Information is sparce, however, on correlations between chemical structure and biological absorption. One sub-group of flavonoids is characterized by containing one or more \textit{ortho} hydroxyl pairs called catechol groups. These catechol flavonoids are of special interest as the presence of the catechol groups changes the physical properties of these compounds in terms of their intermolecular interactions. In this study, a set of catechol flavones, a simple sub-group of flavonoids, were examined for their octanol/water partition coefficients (LogP$_{oct})$ at various standard pH values within the human digestive system to predict their possible mode and extent of absorption in the body. Using NMR techniques, Abraham summation, and methods of chemical approximation, the hydrogen bonding acidities were also calculated for the catechol-flavones to further assess and confirm their permissibility through the body. Through further research and development, these naturally produced compounds could prove to be viable medical treatments for many neurodegenerative and cancerous diseases. [Preview Abstract] |
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A01.00169: High Latitude Signatures of SI and SSC Events Chynna Spitler, Mark Moldwin, Brett McCuen, Adrienne Traxler Sudden Impulse (SI) events and Sudden Storm Commencements (SSC) are rapid geomagnetic variations associated with a compression of the magnetic field. Starting in 2006 Ebre Observatory, the IAGA international database on rapid magnetic variations, began to differentiate SI events from SSCs. These events have different magnetic characteristics depending on local time and latitude. Starting in 2006 and ending with the last definitive published dataset, the module SeaPy within Python is used to perform a superposed epoch analysis on SI events and SSCs for high latitude stations and low latitude stations. In relation to low latitude station onset times, we find systematic behavior of the total field strength and North-South component of the magnetic field at high latitudes. Specifically, the SI and SSC signatures are delayed and the compression signature can be highly variable from event to event. [Preview Abstract] |
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A01.00170: X-Ray Diffraction and Structural Analysis of Shark Vertebrae Kathryn Griggs, Gabriela Gonzalez Just like how rings correspond to the growth record of trees, some mineralized tissues of mammals contain temporal sequences of tissue development. Shark vertebrae consist of cartilage mineralized with hydroxyapatite (HA). A recent study of vertebrae of seven shark species found that this tissue material stiffness and strength are similar to those of mammalian trabecular bone. The periodic array of atoms in the HA nanocrystals in shark vertebrae produce peaks of diffracted intensity. The present project studied thousands of x-ray diffraction patterns of shark vertebrae collected at the Advanced Photon Source (APS) at Argonne National Laboratory. The only crystalline phase found was HA, and HA lattice parameters varied periodically in a spatial pattern consistent with growth bands observed optically. [Preview Abstract] |
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A01.00171: Direct Laser Writing: Comparing Two-Photon Polymerization and Low-One Photon Absorption Polymerization Kris Tulloch, Christopher Lafratta, Cecily Rosenbaum, Tahmid Siddique, Anders Dollard, Nasif Hossain, EJ Worth New methods of microfabrication, such as two-photon polymerization (TPP), are important for the creation of modern micro-analytical, optical, mechanical, and electrical devices. TPP uses an ultrafast laser to polymerize a liquid resin into a solid polymer at a precise location referred to as a voxel. By scanning the laser in the resin a 3-D shape of arbitrary geometry can be created. Following the development of the unreacted resin, the microstructure can be imaged by electron microscopy. Microfabrication can also be done using low-one photon absorption (LOPA) polymerization, a more cost-effective method. The purpose of this project is to compare structures made by TPP and LOPA to evaluate if the simpler laser needed for LOPA can produce structures with the same characteristics as TPP. In particular, we set out to evaluate the voxel size limit, fabrication speeds, and proximity effect between the two methods. However, more data needs to be collected both for TPP and LOPA prepared samples to draw a conclusion as to the limits of each method. In addition, the proximity effect in both TPP and LOPA also needs further investigation. [Preview Abstract] |
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A01.00172: New Possible Application Area for Magnetocaloric Materials: Hyperthermia Method Ekin Secilmis, Ali Osman Ayas, Ahmet Ekicibil The conventional Hyperthermia Method used for cancer treatment today heats the whole body or specific parts of it. This way of implementing the Hyperthermia Method presents hazards, like destroying healthy cells. Our work presents a new approach for the Hyperthermia method, making use of the magnetocaloric effect to overcome the problems related to the heating of the actual bodily tissue. In order to bring practical use of this new approach, the relevant characteristics of magnetocaloric materials for the Hyperthermia method have been determined. These characteristics are the magnetic entropy change, the adiabatic temperature change, the Curie temperature, and the Full Width at Half Maximum. Some example materials complying with the required characteristics are obtained from the literature, and listed in our paper. That said, there are additional parameters that are helpful in determining the most appropriate material. We are also reporting possible ways to obtain new magnetocaloric materials for use in the Hyperthermia method. [Preview Abstract] |
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A01.00173: A Brief Survey of Introductory Quantum Cognition Kimiasadat Mirlohi This presentation is an introduction to quantum cognition. Quantum cognition is the overlap of quantum physics, psychology, sociology, and neuroscience. This presentation provides a summary of the basic ideas in this field, as well as an overlook on two scientific papers that explore multiple experiments demonstrating the advantages of quantum mechanics probability principles over those of classical mechanics in the study of human behavior and decision making in the presence of ambiguity. The conclusion of this study is that in the presence of ambiguity, humans make decisions that would not be considered ``rational'' in a classical sense. Despite this, we can define patterns through quantum physics probabilistic laws and make significantly accurate predictions. This project, by no means, claims there to be any quantum mechanics presence in the brain; rather, it introduces quantum physics as a tool that has been found helpful over the past few decades in explaining human behavior. Quantum cognition changes the common view of quantum physics as an abstract field and applies its principles to our daily behaviors, making an amazing example of abstruse ideas having mundane applications. [Preview Abstract] |
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A01.00174: Projection of Global Ocean Deoxygenation with an Idealized Model of Ventilation and Biogeochemistry Brittney Vroom, Takamitsu Ito There is a growing evidence that anthropogenic climate change caused deoxygenation of global oceans in the past fifty years. This project developed a two-box model to project the ocean deoxygenation of this century. The model represents the upper ocean ventilation and biological processes, whose sensitivities to climate warming play a central role in setting the oxygen loss through the end of the century. The sensitivity of ocean ventilation to climate warming and increasing ocean stratification is constrained by minimizing the mean square error of the model-observation misfit for subsurface temperature and oxygen observations for the last 60 years. The data-constrained box model is then used to project future oxygen loss under three separate warming scenarios compiled from the coupled climate simulations of CMIP6 models. Three scenarios are examined including SSP126, 245, 585 ranging from the case with strong reductions in GHG emissions to the one with business-as-usual fossil fuel emission. Our result suggests that the warming-induced reduction in ocean ventilation significantly increases the severity of ocean deoxygenation by more than a factor of two. These findings highlight the importance of understanding the sensitivity of ocean ventilation and the societal decisions to reduce carbon emissions to minimize the loss of oxygen and to protect marine habitats. [Preview Abstract] |
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A01.00175: Evaluation of a new task-based automatic dose and keV selection tool for virtual monoenergetic imaging using a whole-body photon-counting detector CT Jia Wei, Kishore Rajendran, Jamison Thorne, Jeff Marsh, Kristin Burke, Shuai Leng, Cynthia McCollough Computed tomography (CT) is widely used as a diagnostic imaging modality. Recently, a new CT technology called photon-counting detector (PCD) CT has been introduced for routine clinical use. In this recently introduces PCD-CT system (NAEOTOM Alpha, Siemens Healthineers GmbH, Forchheim, Germany), a new tool (CARE keV, Siemens Healthineers GmbH) is available to automatically reduce radiation dose and selects an optimal energy (keV) level for virtual monoenergetic images (VMI) based on the imaging task (\(70 keV\), \(65 keV\), \(60 keV\), and \(55 keV\) for non-contrast, calcium/bone, soft tissue with contrast (ST), and vascular tasks, respectively). We evaluated the performance of CARE \(keV\) for assessment of Contrast-to-Noise Ratio (CNR) for differnet phantom sizes and radiation dose levels compared to a conventional scan acquired at single tube potential without CARE keV. The results suggested that among all phantom sizes, average dose reduction compared to the non-contrast task ranged from \(8.92\%\) to \(38.81\%\). Additional investigations found that \(40 keV\) and \(50 keV\) yielded similar or improved CNR for both vascular and ST task when compared to the default keV level. [Preview Abstract] |
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A01.00176: Algorithm that Recovers Hamiltonian Parameters in Imprecisely Characterized Systems Hebah Goderya, Wolfgang Pfaff The field of quantum optimal control has opened doors for quantum technology. In experimental practice, however, the effectiveness of this is often limited by imprecise characterization of the quantum system's parameters. With this algorithm we develop a scheme to recover these parameters. By utilizing open-loop optimization via a gradient-based search, we preform a direct search for uncertain parameters in a given system by a closed-loop search based on experimental feedback. This Letter provides proof of concept and demonstrates the potential in this approach. [Preview Abstract] |
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A01.00177: Classification of Solar Wind Structures via Unsupervised Machine Learning Mavis Stone, Amanda Joy Camarata, Anna Jungbluth, Andrés Muñoz-Jaramillo, Hala Lamdouar, Nathan Miles, Sudeshna Boro-Saikia, Marcella Scoczynski, Sairam Sundaresan, Anthony Sarah The solar wind is a constant stream of plasma structured by the solar magnetic field that is radially ejected from our Sun to the boundaries of our solar system. Organizations such as NASA and ESA have gathered nearly half a century of data on solar wind, but much of it has yet to be analyzed for improved understanding of solar wind evolution. So far, heliophysicists have primarily focused on understanding specific structures such as interplanetary coronal mass ejections and large-scale discontinuities. However, there exist many structures that have yet to be discovered. In this work, we create a novel, unsupervised framework to catalog both known and unknown structures using magnetic field time series data from the Parker Solar Probe. We combine iSAX indexing and HDB Scan clustering to identify, retrieve, and cluster similar magnetic field structures into an indexed catalog. With this catalog data, heliophysicists can better understand the origins and evolution of the solar wind. Our method can be used on other time series data including, but not limited to: plasma velocity, density, and electron composition, all of which can offer further insight into space weather and its impact on Earth and our satellites as well. [Preview Abstract] |
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A01.00178: Engineering And Visualizing Quantum States Srishti Nautiyal, Gregory Bentsen, Brian Swingle Quantum states are resources for storing and processing quantum information with applications to quantum simulation and computation. Here we describe techniques to engineer and visualize quantum states in single SU(2) spins. For visualization, we use the Wigner function to represent a quantum state on a Bloch Sphere. These quantum states are engineered using scrambling dynamics and weak measurements. Scrambling dynamics delocalize quantum information throughout a quantum system, and are achieved here using chaotic spin dynamics generated by a combination of squeezing and rotations. Conversely, weak measurements disturb a quantum state very little by partially collapsing the state. Consequently, there is a competition between scrambling and Measurement, leading to a measurement-induced phase transition (MIPT) between a delocalized quantum state where information is inaccessible to simple probes or a collapsed quantum state where information is easily accessible to simple probes. These delocalized states are robust to perturbation because there is a Quantum Error Correcting Code to protect quantum information from errors. Future work will explore possibilities for using such codes to robustly store quantum information in single SU(2) spins. [Preview Abstract] |
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A01.00179: Possible Relict Glacial Landforms on Venus Alana Macken, Pascal Lee Venus presently has high surface temperatures near 477\textdegree C, a dense CO2 atmosphere, and no possibility of stable condensed H2O at its surface [1]. However, surface conditions might have been different in the past. Models of Venus' atmospheric evolution and terrain interpretations suggest that wetter, more Earth-like climate conditions once prevailed [2-3]. In a survey of the planet's surface imaged by Magellan's orbital radar at 75 mpp, we searched for morphologic signatures uniquely associated with cold-climate features. In SW Aphrodite Terra, at 17.7\textdegree S, 51.0\textdegree E and 17.7\textdegree S, 58.0\textdegree W, we identified several systems of linear trough valleys with short tributaries, each with stubby cirque-like valley heads, joining the main trough at right angles. The morphologies are analogous to terrestrial glacial trough valleys and their feeder glacial tributaries. We interpret the Venusian features to be possible relict glacial landforms, now flooded by volcanic lavas. If convergence of form is not at play, then Venus experienced glaciation(s) in its past, implying drastic change in surface conditions over time. References: [1] Taylor, F. W. et al. (2018). \textit{Space Sci. Rev., 214}. [2] Way, M. J., {\&}amp; Del Genio,A. D. (2020).\textit{ JGR Planets}, 125. [3] Khawja, S. et al. (2020). \textit{Nature Comms}. [Preview Abstract] |
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A01.00180: Planarian Behavioral Box For Education Outreach Yashvi Patel, Andrew Huynh, Danielle Ireland, Dr. Eva-Maria Collins This project involves making a behavioral box for middle school students to perform stimuli experiments on \textit{Dugesia japonica} planarians which are flatworms approximately 5 mm long and 1-2 mm wide and are highly responsive to changes to their environment. The box will supplement the students' understanding of stimulus-response reactions and quantitative image analysis. Five behaviors of the planarians are studied: Normal locomotion, thermotaxis (movement to colder regions), chemotaxis (they move closer to food sources), phototaxis (planarians move away from light), and scrunching (change in movement as an escape mechanism). For ease of mass manufacture and repair, the box has to be made from inexpensive readily available materials. Swarthmore alumni, Andrew Huynh, created the initial prototype. This included design, coding a Raspberry Pi, and partially implementing two experiments. Building upon the initial prototype created by the previous undergraduate, I have focused on making a new prototype for a smaller box, with more readily available materials. The box is now a cube made of plywood (each side is 20 cm long), its volume halved from the original prototype. For thermotaxis, we are creating a temperature gradient using a cold acrylic placed under a small region of the petri dish with planarians. A light gradient for phototaxis is being created by using a flashlight. For chemotaxis, a paste made of dried liver is placed into the petri dish using a feeding tube. [Preview Abstract] |
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A01.00181: Evaluating the Impacts of Seagrass Restoration on Ecosystem Carbon Sequestration Hailey Gilman Coastal ecosystems capture carbon from the environment, mitigating the climate effects of human carbon emissions. Seagrass contributes to this \textit{blue carbon budget,} storing carbon within healthy meadow beds through a number of natural processes. However, much of the carbon stored within seagrass beds comes from beyond the beds and there is little information evaluating the impact of seagrass on carbon storage in adjacent sediments at a bay-wide scale. This study quantifies the relationship between carbon stored within sediments adjacent to restored seagrass beds at the Virginia Coast Reserve along the Eastern Shore by evaluating data collected before and after restoration. Sediment samples were taken at 27 locations within Hog Island Bay, a shallow coastal lagoon, before (2003-2004) and after (2020) seagrass restoration. Samples were analyzed for percent fine sediment using wet sieving and percent organic matter by loss on ignition. The change in these parameters for each sampling location was calculated and the distance from the nearest restored seagrass bed was determined using ArcMap Pro and Excel 2016. Many of the sediment samples beyond 1300m from restored seagrass showed a net decrease in carbon storage, indicating that some carbon may be relocated from other parts of the ecosystem, not a true enhancement of carbon storage. This relationship seems driven by linear distance to restored seagrass sites (R2$=$0.21, p$=$0.2), unaffected by percent fine sediment, water residence time, and sample site depth. [Preview Abstract] |
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A01.00182: Acoustic Demultiplexer Mediated by Stub-Loaded Waveguides: Computational Simulation Jennifer Lopez, Alexander LaVerde, Carina Vazquez, William Robertson Previous studies of stub-loaded waveguides have used resonant structures such as Helmholtz resonators, closed- ended and open-ended stubs, and loop filters to research Fano and electromagnetically induced transparency (EIT) resonances. As a result of constructive and destructive interference, Fano resonances arise. Based on acoustically induced transparency (AIT) and Fano resonances, the cross-shaped acoustic demultiplexer is the center of our study. This work describes an acoustic wave demultiplexer based on the use of stub-loaded waveguides containing one input line on top of two output lines. A demultiplexer selectively transmits specific frequencies from an input signal while reflecting all the rest. The results of theory, simulation, and experiment are compared in this study. Using Python, we were able to model the transmission along each output in a Y-shaped waveguide based on a theoretical model. Using COMSOL Multiphysics, we simulated the same cross-shaped structure showing that it replicates the theoretical curve as given by our Python program. Finally, the system was characterized experimentally using the same parameters. [Preview Abstract] |
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A01.00183: Overview of Helium Conservation at UIUC Anna Przybyl Have you ever had an MRI done? The element that makes MRIs possible—and many other scientific instruments—is helium. When in liquid form, this incredibly important resource boils at around 4 degrees Kelvin. It is used in scientific applications when a system needs to be kept at such cold temperatures. Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) machines operate using superconductive magnetic coils. These coils must be kept at a cold temperature otherwise the superconductive properties will be lost. Some scientific systems are very sensitive to vibrations, and must also be cooled with liquid helium. Therefore, liquid helium is invaluable in certain scientific and medical applications. When not contained, helium quickly burns up and can escape the atmosphere due to how light the atoms are. Most helium on earth was trapped under earth’s crust when the earth formed. Some helium is still being produced today, from radioactive decay, but this process takes millions of years, and is not a viable way to produce helium. Thus, it is important to preserve helium, contain it, and reuse it when possible. I will be detailing helium conservation efforts at UIUC, and discussing why it is important to constantly monitor and upgrade such a system. [Preview Abstract] |
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A01.00184: Measuring Optical Coefficients and Band Edge of SubPc, p-PDI and F16CuPc Olivia Protano, Alexi Arango To understand the limits to high efficiency disordered semiconductor solar cells, we must first understand how light interacts with each individual layer. We did so by determining each material's optical coefficients and band edge energies. We measured absorbance and transmission with the FilmTek 3000, used an optics model to fit the data and predicted the optical constants n(E) and k(E). We analyzed the extinction coefficient vs photon energy data to determine the material's band edge energy. We will input our resulting data to the solar cell simulation package GPVDM to inform us of fundamental properties of our materials to then help us design the ideal solar cell. [Preview Abstract] |
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A01.00185: Abstract Withdrawn
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A01.00186: Effects of Humidity on the Conductive Properties of M55J Carbon Composites Crystal Tingle The focus of this research is to characterize advanced materials that are being considered for use in the harsh environment of outer space. The material of interest is M55J, a carbon fiber reinforced polymer (CFRP), which has already been used or tested for space applications. An example of which is the James Webb Space Telescope, Lunar Gateway Space Station, and more future projects to come. In space, materials will be bombarded by solar winds and radiation, which can cause the component to build charge. This phenomenon is referred to as spacecraft charging. It is of great importance to ensure that spacecraft remain in a controlled environment, so characterizing the electrical properties of materials helps to guide designs specific to unique applications. M55J is an MJ-type carbon fiber, embedded in a thermoset epoxy resin. This gives the material a favorable strength-to-weight ratio, and typically a very low resistivity $(0.8 \times 10^{-3} \Omega \cdot cm )$. In this research, we will have three groups of M55J. First will be M55J soaked in water, the second will be M55J baked at high temperatures in an oven, and the third will be M55J baked and left to atmospheric air and temperatures. The purpose of this process is to characterize M55J at a controlled level of maximum humidi [Preview Abstract] |
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