Bulletin of the American Physical Society
Mid-Atlantic Section Meeting 2021
Volume 66, Number 18
Friday–Sunday, December 3–5, 2021; Rutgers University, New Brunswick, New Jersey
Session F01: Poster Session |
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F01.00001: Construction of Detection Electronics to Assess Superconducting-to-Normal Switching Events in a Josephson Junction Dan Fauni, Gianna Calligy, Keeran Ramanathan, Roberto Ramos Wide interest in superconductor-based quantum computing motivates our investigation of one of the mechanisms driving the readout of the quantum state of a Josephson junction. Escape of a Josephson phase particle from the zero-voltage state of a current-biased, hysteretic Josephson junction has been studied experimentally, in agreement with Kramers theory for the escape of a Brownian particle from a potential well. The effect has been investigated in devices made from single-gap superconductors such as Al and Nb, high-Tc superconductors, and multi-gap superconductors such as MgB2[1]. We discuss the progress we made in building electronics that allow physics undergraduates to perform similar experiments using a 2 Kelvin cryocooler, potentially on multi-gap superconductors. The detection electronics consists of a current ramp bias circuit, a universal time interval counter measuring switching statistics, and a Schmidt trigger detection circuit that amplifies and measures switching of voltages of a Josephson junction. This work is being performed by a team of undergraduates. [1] S. Carabello, et al., J. Appl. Phys. 120, 123904 (2016) [Preview Abstract] |
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F01.00002: Machine Learning Magnetic Parameters from Hysteresis Loops Bradley Fugetta, Kun Yue, Amy Liu, Gen Yin First-order reversal curve (FORC) hysteresis loops of a magnetic material contain detailed information about the underlying physics of the material, but can the material’s magnetic Hamiltonian parameters be extracted from this data? Though it is impossible for humans to accurately guess the magnetic parameters from FORC data, we hypothesize that a trained neural network can do so. We have generated over 10,000 images of FORC data using mumax$^3$, a micromagnetics simulation program, and are using that dataset to try to train a customized convolutional neural network (CNN) to estimate magnetic parameters solely from FORC images. We trained the CNN with various loss functions, output distributions, and network shapes to tune the hyperparameters for this particular problem. The neural network shows clear signs of learning and is capable of estimating the saturation magnetization. We continue to tune the hyperparameters of our CNN to lower the error on its predictions, and we hope to train the CNN to predict other Hamiltonian parameters to the same accuracy as the saturation magnetization. [Preview Abstract] |
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F01.00003: Speed cubing and secret sharing Michael Farhy, Ian Morrison We develop an analogy between the $4\times 4 \times 4$ Rubik’s cube and systems envisioned for topological quantum computing. We construct an energy function which assigns an energy to each Rubik’s cube pattern (“state”) and which is minimized by the solved pattern. Face turns correspond to low-energy excitations while “slice" moves are high-energy excitations. Low-energy states correspond to the solved and nearly-solved patterns. These low-energy states separate into four superselection sectors which are distinguished by topological properties of their patterns (regarded as permutations of the solved pattern). These topological properties cannot be altered by low-energy excitations of the cube. Thus, at least at low energies, it is possible to encode information in the $4\times 4\times 4$ Rubik’s cube in a way that is topologically protected. High-energy excitations of the cube can alter the topological properties of a pattern and change the superselection sector. The energy function we use is motivated by speed cubing: the steps typically performed to solve the cube correspond to systematically minimizing the energy function. The superselection sectors we use to encode information are commonly encountered when speed cubing and are known in this setting as “parities." [Preview Abstract] |
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F01.00004: Dynamics and Thermodynamics of a Chiral Symmetry Split Fermionic System Xindong Wang, Xiaoguang Zhang Recent work by Wang et al. proposes a self-consistent effective Hamiltonian that breaks the time reversal/chiral symmetry of the full Hamiltonian of a many-body fermionic system. By adding back the chiral conjugate of the effective Hamiltonian, the chiral symmetry can be restored. In this work, we study the dynamics and thermodynamics of an exactly solved chiral symmetry split system prescribed by a pair of chiral conjugate non-interacting effective Hamiltonian. Results on the dynamical evolution of a pure state are analyzed in the Hilbert space spanned by one of the chiral symmetry split basis states. Quantum decoherence is shown to be the results of the overlap of the two chiral symmetry broken vacuum by properly taking the thermodynamic limit in terms of single fermion degree of freedoms $N$. [Preview Abstract] |
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F01.00005: Creating Liquid-core Polymer Nanoparticles Using Flash Nanoprecipitation Ugomma Ugwu-Uche, Edward Van Keuren, Sophia Taylor, Yuri Chung Abstract: Nanoscience is seeing significant growth in the area of synthesis and application of multicomponent and/or multifunctional nanoparticles. We're working on methods to synthesize particles containing a liquid core and a polymer shell. We show that liquid core nanoparticles can be formed using flash nanoprecipitation. Flash nanoprecipitation takes a solution and mixes it rapidly with a miscible solvent. Here is our research where we create water core nanoparticles using an inverse process. Briefly, we inject an aqueous solution containing a water-soluble polymer into an organic solvent that is miscible with water. We've characterized the particles with a light scanning electron microscope, recording their widths and radii. The encapsulation of molecules into polymer micro and nanoparticles could potentially provide materials for a number of applications like the use of nano-precipitation in the process of drug formations/delivery and possibly non-invasive surgery. Results could shed more light on how to control final particle size for formation and ensure that active pharmaceutical ingredients are fully encapsulated into the polymer particles. [Preview Abstract] |
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F01.00006: Synthesis and Characterization of Polystyrene Nanocapsules Sophia Taylor, Yuri Chung, Ugomma Ugwu-Uche, Leah Chen, Vereni Amaya Aparicio, Eleni Hughes There has been a great deal of recent research on the synthesis and application of multicomponent nanoparticles.~ Nanocapsules, which are nanoparticles with a liquid core and solid shell, are one example. These materials have shown promise in applications such as in pharmaceuticals and food additives. We have developed a series of nanocapsules using a method known as flash nanoprecipitation, in which a solution is rapidly mixed with a miscible non-solvent.~We synthesized nanocapsules consisting of a polystyrene shell with a liquid core of a hexadecane. The nanocapsules were characterized using dynamic light scattering, atomic force microscopy, and scanning electron microscopy. We were able to determine how different compositions of the initial solution affects the resulting nanoparticles. We also investigated how the size of these particles change over time.~We will discuss the synthesis of these particles and show that their formation can be described using a simple droplet model. [Preview Abstract] |
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F01.00007: Study on the Fluorescent Functionalized Fullerenes as Contrast Agents For Bio-imaging Diana Oh, Richard Kyung An adequate balance between biochemical stability and reactivity for the agents must be determined in order to effectively relax or stabilize the contrast agents used in the detection of tumor cells in the body. Due to the lack of stability and the potential of toxicity of iodine and gadolinium chelates, even though they are less toxic than the gadolinium element itself, fluorescent functionalized fullerenes are studied in this paper to see if they stabilize or reduce the LD50 value despite the increase of reactivity. Other than the functionalized fullerenes with various functional groups attached, transition metal oxide nanoparticles and nanoscale metal-organic frameworks could also significantly contribute to the medical field with relatively high stability and effective transportation method for delivering significant amounts of paramagnetic metal centers, respectively. This paper found that the PC61BA-(Gd-DO3A) is the most thermodynamically stable, amongst tested functionalized fullerenes, with the lowest optimization energy of 13894.8 KJ/mol. Even though TiO2 is relatively stable, it is difficult to certainly claim that one molecular compound is the best contrasting agent. [Preview Abstract] |
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F01.00008: Evaluating the Reflective Spectral Profiles of Lipid Membranes in Relation to the Concentration of Cholesterol Minares Ehsani, Qi Lu Giant Unilamellar Vesicles (GUVs) are excellent model systems for studying physical aspects of biological membranes where the interaction between lipids and proteins takes place. The key advantage of GUVs is that they can be observed directly under the light microscope because of their large sizes, comparable to those of mammalian cells. Numerous studies have shown the effects of cholesterol on the phases and structures of the lipid-cholesterol membranes. The lipid ``structures'' inside the membrane ocean are known as lipid rafts. Cholesterol (CHOL) increases the rigidity of lipid vesicles by forming raft-like structures. In this project, we focused on the lipid reflective spectral profiles obtained from the hyperspectral dark-field microscopy and we studied their correlations to different concentrations of cholesterol (10, 20, 30, and 40 mol{\%}). Reflective spectral profiles of GUVs with 20 mol{\%} CHOL were found to be distinctly different from the other concentrations in both peak wavelength and FWHM (full width at half maximum). This finding was consistent with other studies, suggesting that the hyperspectral analysis technique can be used to characterize the phase and integrity of lipid membranes. [Preview Abstract] |
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F01.00009: Implantable Drug Delivery Using Polycaprolactone with Thermally Triggerable Release Joseph Farina, Makarand Paranjape, Daniel O'brien Implantable drug delivery systems offer many advantages over traditional systemic routes of delivery such as improved targeting~with localized delivery, minimization of side effects, and a decreased amount of drug required to treat the disease. However, these systems also face many barriers, for example the need to remove the implant, and the potential for it to elicit an immunoresponse. Polycaprolactone (PCL) is a biodegradable polymer with a slow degradation rate and a melting point of 60\textdegree C, making it a suitable choice for a meltable drug sealing layer for on-demand~drug release~from an implantable device that will eventually degrade in the body without need for excision. Initial findings on the thermal characteristics of thin PCL sealing layers on~thin-film gold~microheaters are reported here. Further, a calibration curve for~the thermochromic dye, europium thenoyltrifluoroacetonate (EuTTA), in PCL was generated that can be used to generate a fluorescent microthermal image map~for PCL.~These results both pave the way for the use of PCL films in triggered-release, implantable drug delivery systems, as well as offer new insights into~the use of this fluorescent imaging technique with other novel materials.~ [Preview Abstract] |
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F01.00010: Study on the Nano-scaled Functionalized Biochemical Particles for the Treatment of Neurodegenerative Diseases Eunki Shim Iron homeostasis is currently emerging as a key factor in maintaining brain health and preventing disease. In several common neurodegenerative diseases such as Alzheimer’s Disease (AD) and macular degeneration, dyshomeostasis of redox-active metals and subsequent detection of elevated levels of redox-active metals such as iron and copper in the brain suggests that such metals play a significant role in the pathogenesis of such disease. In this paper, computer programs were used to model various chelators that were potential candidates for iron chelation therapy in the brain. The molecules were assessed for thermodynamic stability, reactivity/conductivity, and polarization. Thermodynamic stability could be measured through optimized energy. Generally, as optimized energy decreased, thermodynamic stability increased. Reactivity/conductivity was measured through the dipole moments and may act as a good indicator of how the molecule may interact with surrounding particles in vivo. Lastly, electrostatic potential maps were used to visualize the polarization and assess the reactivity level of each molecule. [Preview Abstract] |
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F01.00011: Study on the Biogenic Organic Metals and Metal Oxide Nanoparticles for Artificial Tissues Eunice Jeong, Dohyun Ahn Right after biomaterial implantation, plasma proteins interact with the molecules in the material surface and it starts to create a proteinaceous coating. The interactions of the proteins with molecules are determined by various parameters including the physicochemical properties of the biomaterial nanoparticles such as topography and activity of the materials and the properties of the protein. To assess the tissue affinity of the biomaterials, the theoretical structure of feasible biogenic organic metals and metal oxide nanoparticles is studied in this study. The physical and biochemical activity of those molecules is thermodynamically and stereochemically characterized after modeling and optimizing them. The ultimate goal of this study is to check for the materials to achieve better physicochemical stability and affinity with tissues. To determine a molecule’s thermodynamic stability, molecular editing software for building virtual molecules and calculating optimized geometry using UFF (Universal Force Field), is used to build the molecules. [Preview Abstract] |
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F01.00012: Particle Tracking Using a Quantum Enhanced Tracker Nicolas DeStefano, Saeed Pegahan, Irina Novikova, Eugeniy Mikhailov, Seth Aubin, Todd Averett The quantum enhanced tracker is a proposed tabletop prototype to optically trace single particle paths with high resolution in three dimensions. The electrons pass through a volume filled with Rubidium atoms, and their presence perturbs atomic quantum states and can be detected optically. Here, we show preliminary detection of low-energy electrons in two dimensions through a polarization rotation scheme. We plan to measure AC electric field effects on Rydberg states as a sensitive electrometer to detect low-energy particles. This apparatus will be implemented at Jefferson National Laboratory as a pristine method of detecting charged particles based on coherent properties of Rubidium atoms. [Preview Abstract] |
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F01.00013: Towards the use of electron ejection trajectories as a direct in-situ gauge of super intense lasers Smrithan Ravichandran, Calvin He, Andrew Longman, Luis Roso, Robert Fedosejevs, Wendell Hill With the advent of multi-petawatt laser facilities around the world comes the concomitant need for in-situ, reliable tools to measure the focal intensities with high precision and accuracy. Current methods to estimate the intensity largely rely on indirect approaches that are not made in real time. Thus, these methods are not sensitive to fluctuations from shot-to-shot, which prohibit real-time characterization of the pulse. In this presentation, we propose a method to extract the pulse intensity from the measurement of electron trajectories -- energy and angular distributions -- subsequent to ionization of residual gas by the pulse. We will discuss how to exploit over-the-barrier ionization to correlate the ejected electrons with their parent ion, which can be measured with a time-of-flight detector. The presentation will include an outline for a prototype experiment. [Preview Abstract] |
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F01.00014: A programmable ramp generator for laser cooling and trapping John Huckans Arduino is an open-source electronic prototyping platform allowing users to quickly create interactive electronics instrumentation. Teensy 3.6 is a similar but more capable platform based on a 180 MHz Cortex-M4F microcontroller with a built-in 12-bit DA converter whose IDE based on C/C$++$ is almost identical to the Arduino environment. Using Processor software to create a GUI, we have designed and built the hardware and software of an instrument which is ubiquitous in laser-cooling and trapping experiments. Our instrument, called RampBox controls the amplitude and frequency sweeps of a typical AOM RF driver. We present the design, development, and performance of the RampBox. [Preview Abstract] |
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F01.00015: Characterizing relativistic Thomson scattering angular distribution as a function of laser intensity Calvin He, Andrew Longman, Smrithan Ravichandran, Jon Apinaniz, Jose Perez-Hernandez, Massimo De Marco, Luis Roso, Robert Fedosejevs, Wendell Hill The strength and angular distribution of light emitted by relativistic Thomson scattering of electrons in the focus of an intense laser subsequent to ionization of residual gas is intimately related to the intensity of the laser the electrons experience. While the dynamics is very complicated, our simulations indicate that in certain wavelength bands the angular distribution exhibits a prominent depression when viewed in the E-k plane, the location of which changes with intensity. In this presentation, we will present the results of the simulation and our preliminary experimental measurements that support the predictions of the simulations. The preliminary measurements were performed with an angular resolution of only 10° and a temporal resolution of 5 ns. We will present a design for an upgrade to our experimental approach that will enable angular distribution measurement to be made with higher angular precision (~1°) and better temporal resolution (~5 ps with a streak camera) leading to less interference from scattered light and recombination radiation. Finally, we will discuss how to verify the intensity associated with specific locations of the dip by employing a time-of-flight ion detector and estimations of the appearance intensity of specific ionization stages. [Preview Abstract] |
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F01.00016: Study on the Spatial and Frequency Domain for the Enhancement of Medical Images Using the Fourier Transformation Ji Soo Hwang, Richard Kyung To get the image from MRI, frequency information has to be transferred to the image using mathematical and computational transformations. Ample amounts of the frequency data can be obtained from the MRI process; however, not all the frequency information is needed to determine the final image. Often, the process of transformation from the frequency domain to the image domain requires time because inverse Fourier Transformation takes every frequency point to determine the final output image. However, the employment of a proper method using mathematical and statistical knowledge can result in reduced domains of frequency, which will be used to determine output images in an efficient manner. In this paper, K-space was constructed from the MRI image of the human organ using the MATLAB program. Different proposed filters were applied on the full K-space in order to find the most efficient filter, which can be used to produce the best MRI image. Many filters are good at reducing the size of K-space, but most of those filters had the unwanted ringing effect. New computational experiments were performed with several modified filters to reduce the ringing effect and improve the resolution of an MRI image to a degree, and finally proposed an efficient function as a new filter. [Preview Abstract] |
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F01.00017: Modeling the Giant Lensed Arc in Abell 370 Lana Eid, Charles Keeton, Catie Raney Gravitational lensing by galaxy clusters magnifies and distorts distant galaxies, which can let us study them at higher resolution than otherwise possible. In order to determine the morphology of the source, the observed images need to be de-lensed. Lens models are generally constrained using image positions and assuming point sources. We use giant arcs to study the effects of an extended source model on both the cluster mass model and the reconstructed source galaxy. A giant arc provides more constraints than images from an unresolved point source, but it requires a more complex model that accounts for the structure of the source. We seek to determine whether improvements to the lens model and reconstructed source merit the difficulty of handling the extra constraints. We present an analysis of the giant arc in Abell 370 using an analytic model consisting of an elliptical Sersic source. In future work, we will extend the analysis using pixelated source reconstruction. [Preview Abstract] |
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F01.00018: An MCMC approach to measuring the explosion properties of young Supernova Remnants Prasiddha Arunachalam, John P Hughes, Luke Hovey Supernova remnants (SNRs) result from the interaction of the debris of supernova explosions with the surrounding interstellar medium (ISM). They emit across the entire electromagnetic spectrum and offer a unique way to study explosions and their effects on the ISM. Theoretical models for SNRs involve detailed, often messy ionization and temperature calculations to predict the expected emission from different charged species. These are then compared with observations of SNRs to infer the properties of the parent explosion. Here, we present an alternative approach that only uses the fluid-discontinuities to measure the explosion properties of a SNR's originating explosion. By fluid-discontinuities, we refer to the outward propagating forward-shock (FS) or blast wave propagating into the ISM, and the reverse-shock (RS) traveling back into the ejecta. We set up a Markov Chain Monte Carlo formalism to compare observed properties of SNRs such as the FS/RS radius and velocity with similarity solutions of young SNRs expanding in a uniform ambient medium. We apply this method on SNR 0509-67.5 to constrain its age, explosion center, energy, and the density of the ambient medium surrounding the remnant. [Preview Abstract] |
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F01.00019: A multiwavelength approach to constraining the Merger Properties of ACT-CL J0034.4+0225 Peter Doze, John Hughes, Charles Keeton, Matt Hilton, Catie Raney ACT-CL J0034.4+0225 is a massive galaxy cluster in an intriguing dynamical state, that is detected at high significance by the Atacama Cosmology Telescope (ACT). We obtain multiwavelength data from \textit{Chandra}, SALT, \textit{DES}, and \textit{Hubble}. Several mass proxies from the \textit{Chandra} data yield a total mass within the range $M_{500} = 5-8\times 10^{14} M_\odot$, which is generally consistent with the literature. The X-ray image shows two clear surface brightness peaks, each associated with a bright cluster galaxy (BCG). We determine the projected distance between the peaks and the velocity difference between the BCGs. These measurements are constraints for comparing ACT-CL J0034.4+0225 with N-body/hydrodynamic galaxy cluster merger simulations. The constraints restrict the suite of simulations to those within 1.4 Gyr of first pericenter, while the mass ratio and merger impact parameter remain largely unconstrained. We additionally perform a strong lensing analysis with the \textit{Hubble} data and simulations, leading to a favored mass ratio of 3:1 also near pericenter. Deeper \textit{Chandra} observations, multicolor HST observations, and new simulations would produce better constraints on the properties of this interesting merger. [Preview Abstract] |
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F01.00020: An Empirical Calibration of the Tip of the Red Giant Branch in the Near-Infrared Max Newman, Kristen McQuinn Precise distance measurements to nearby galaxies are fundamentally important in astrophysics. In particular, extragalactic distances have enabled precise local measurements of the Hubble constant. One of the most robust ways to measure distances to nearby galaxies is using the stable and predictable brightness of stars in a specific phase of stellar evolution, namely tip of the red giant branch (TRGB) stars. Traditionally, TRGB-based distances are best measured at optical wavelengths where the chemical content, or metallicity, of stars only modestly impacts the TRGB luminosity. The TRGB in the near-infrared (NIR) is up to 2 magnitudes brighter than in the optical, increasing the distance range over which precise TRGB-based distances are feasible. However, the NIR TRGB luminosity is expected to have greater metallicity dependence compared with the optical TRGB. Therefore, for the NIR TRGB to be used for precise distance measurements, the metallicity dependence must be carefully calibrated. To determine the calibration, we use new Hubble Space Telescope observations of 4 nearby galaxies with a range of metallicities. We present initial results, including a demonstration of how the NIR TRGB luminosity changes with metallicity. [Preview Abstract] |
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F01.00021: Development of a Burst Gravitational Wave Detectable Range Visualization Dominic Holcomb, James Terhune, Amber Stuver The Laser Interferometer Gravitational-wave Observatory (LIGO) measures gravitational waves of astrophysical origin.~~A common measure of detector performance used by LIGO is the distance to which a standard binary neutron star merger can be detected.~~While all the detected gravitational waves to date have been of this kind, it is expected that the next class of detected gravitational waves will be from unmodelled or unanticipated sources, also known as ``bursts.''~~This research focuses on developing a measure of the detectable distance for a burst gravitational wave that is sensitive to the near-real time data quality of the detector.~~We have developed software that collects results from the primary burst search algorithm to determine what signal-to-noise ratio is needed to achieve an acceptable false-alarm rate and combines this with the power spectral density of the noise to calculate the detectable distance for a standard burst source.~~The result can be visualized as a time-frequency representation or an average distance over the sensitive frequency range.~~Ultimately, this measure will be automatically generated during the next observing run and used to determine the effect of current data quality on the search for burst gravitational waves. [Preview Abstract] |
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F01.00022: Tracing 3D Magnetic Field Structure Using Dust Polarization and the Zeeman Effect Brandon Shane, Blakesley Burkhart, Laura Fissel, Susan Clark Tracing the full three-dimensional magnetic field structure of a molecular cloud is vital for models that predict star formation rates and essential for studies of galaxy evolution.~ However, it is difficult to observationally trace the magnetic field in star forming regions. We compare Plane-of-Sky (POS) tracers of the magnetic field direction via the polarization of dust grains with~the Line-of-Sight (LOS) magnetic field as traced by the Zeeman effect. We use 3D numerical simulations of star forming clouds run with the AREPO code to determine the statistical relationships between the LOS and POS magnetic fields in order to determine the inclination angle of the magnetic field.~ We find trends between the synthetic polarization measurements and the inclination angle of the strongest magnetic fields. However, there is degeneracy in synthetic polarization measurements when the strength of magnetic energy is weak compared to the turbulence energy. Comparing the LOS magnetic field information allows us to break the degeneracy in the synthetic polarization measurements showing that, if the ratio of the magnetic to turbulent energy (Alfven Mach number, Ma) is known, then the inclination angle of the magnetic field is available from observation. [Preview Abstract] |
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F01.00023: Supermassive Black Holes and the Low Redshift Lyman-$\alpha$ Forest Megan Tillman, Blakesley Burkhart, Stephanie Tonnesen, Simeon Bird, Greg Bryan, Sultan Hassan, Rachel Somerville The Lyman-$\alpha$ forest has been utilized by astronomers for decades to constrain our conceptual understanding of cosmology and the physics of the intergalactic medium. Despite this fact, our theoretical understanding breaks down at low redshift where the observed Lyman-$\alpha$ forest remains in conflict with cosmological hydrodynamic simulations. As seen in Kollmeier et al. 2014, there appear to be missing photons in simulations implying a lack of understanding of the heating mechanisms required for proper levels of photoionization. Additional studies exploring this conflict propose that an updated ultraviolet background and proper implementation of active galactic nuclei (AGN) feedback are enough to resolve the conflict at low redshift. We analyze the effects of AGN feedback models on the low redshift forest. We produce the column density distribution function and Doppler parameter distribution for variations on two different feedback models using the CAMELS simulations. We find that varying the strength of the feedback model and the specific sub-grid model used for feedback can have dramatic effects on the low redshift Lyman-$\alpha$ forest. [Preview Abstract] |
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F01.00024: Exploring new techniques for analyzing variability in white dwarfs Thomas Huckans, Peter Stine As is common with the collection of astronomical data, signals are frequently dominated by noise. However, when performing Fourier transforms of light curves, re-binning data can improve signal-to-noise ratios at lower frequencies. Using data collected from the Kepler space telescope, we sequentially re-binned data up to four times to investigate the improvement of lower frequency (\textless 15 $\mu $Hz) variability in white dwarf KIC 8626021. In addition, the use of phase-space modeling to represent the momentum of the data is explored, in order to find whether random or systematic processes emerge in the luminosity of this white dwarf. [Preview Abstract] |
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F01.00025: Charging of cosmic dust in a plasma Mohit Nigam, Cristian Llerena The data from the Voyager spacecrafts as they left our Sun’s heliospheres has raised interest in the composition of interstellar medium and its interaction with plasma at the boundary of our heliosphere and interstellar space. One of the proposed missions, the “Interstellar Probe” [1], is designed to explore this boundary region. Inevitably the probe will pass through a comprehensive plasma before it reaches interstellar medium that is thought to consist of UV radiation and energetic neutral particles (ENA) [1]. In this study, the interaction of dust with plasma and radiation is investigated. This involves studying the evolution of the plasma potential on the surface of the dust particle as a function of plasma property, secondary ion emissions and photoelectron emissions. [1] https://interstellarprobe.jhuapl.edu/uploadedDocs/papers/588-ISP-Study-2019-Report_PR.pdf [Preview Abstract] |
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F01.00026: Forward-Modeling Helioseismic Signatures Andrey Stejko, Alexander Kosovichev, Valery Pipin Understanding the internal workings of the Sun has always been a difficult task--as the solar interior will most likely be forever inaccessible to direct observations. The discovery of turbulent oscillations of plasma on the solar surface, however, have offered us a new chance to take a look inside, using the same techniques in seismology that are used here on earth. This new field of helioseismology has since become one of the foundational pillars of solar astrophysics, bringing us a wealth of insights into the internal workings of global plasma flows that drive the dynamo generating the solar magnetic field. Many mysteries still remain, however, as noise and systematic errors dominate the helioseismic signals--leading to inconsistent interpretations of observational data. In order to address these uncertainties, we have developed a new 3D global acoustic model of the Sun (GALE--Global Acoustic Linearized Euler), which can be used as a computational test-bed to forward-model local and global techniques in helioseismology across various 3D structures of velocity flows and noise models. This model will help set a baseline that will lead to better interpretations of the signals we observe on the Sun. [Preview Abstract] |
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F01.00027: Study on the Gene Mutations Caused by Intercalation of 4-Aminobiphenyl Compound and BaP Diol-Epoxide in DNA Jana Choe Polycyclic aromatic hydrocarbons such as benzo[a]pyrene (B[a]P) and 4-aminobiphenyl (4-ABP) which alter the levels of Reactive Oxygen Species(ROS) in the lung epithelial cells cause lung and bronchus cancer via DNA mutations. In this research, biochemical and computational simulations were performed to figure out how vaping affects the metabolic conversions of 4-Aminobiphenyl(4-ABP) to 4-ABPdG and benzo[a]pyrene (BaP) to BaP diol-epoxide(BPDE) respectively. Both are chemical carcinogens identified in electronic cigarettes. For computational and biochemical analysis, molecular gene-editing programs were used. The programs enable us to determine the theoretical values of a certain structure’s atomic properties through the Density Functional Theory (DFT). The programs also allow users to build virtually any molecule and optimize its geometry according to various force field options. The Auto Optimize Tool was used for each molecule modeled in this project to determine its optimization energy. The Universal Force Field (UFF) option was selected for each molecule modeled. [Preview Abstract] |
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F01.00028: Development and Implementation of a Numerical Laser Energy-Deposition Model for the PSC particle-in-cell code Abdullah Hyder, Will Fox, Derek Schaeffer, Sophia Malko PSC, a particle-in-cell (PIC) code, is being used to directly simulate experiments involving high-energy-density (HED) plasma plumes. Such simulations are being used for fundamental plasma studies including collisionless magnetized shocks and magnetic reconnection. HED plasma plumes are formed in the laboratory by using high-intensity lasers which ablate solid-density targets. Previously in PSC, an ad hoc plasma heating operator was used to represent the heating of the plasma by the laser, which was manually fitted to match simulations with more well-developed laser absorption models (W. Fox, et al, Phys. Plasmas 2018). To expand the scope of experiments that the code can run, a numerically calculated ray-tracing laser energy-deposition model was developed for and implemented into PSC using existing theory on optical absorption by a plasma. The energy deposited per cell was benchmarked against DRACO, a radiation hydrodynamic model with a well-developed energy absorption model, for both shallow and highly oblique laser incidence angles. The numerical model for PSC was found to be in excellent agreement with DRACO and analytical solutions. [Preview Abstract] |
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F01.00029: Study on the Psychological Stress and Chemical Imbalances Caused by Social Factors Joon Park Psychological stress in modern times can be associated with various social factors, characterized by inadequate social interactions, depression, and chemical imbalance. Researchers have demonstrated that socially isolated individuals are more likely to experience symptoms of stress and depression, particularly if they are without close confidantes or strong supporting social networks. This study is intended to identify the barriers to treating stress and focuses on how psychological stress is associated with depression, loneliness, and social isolation due to socio-behavioral factors and the development of media and technology. In diagnosing stress and depression, it is clear that technological advancements, such as reducing an individual's chemical imbalance, have played a significant role. With the help of technology and science, quantifiable assessment of neurotransmitters has become essential for observing social and behavioral impact. The current trend of studies is also highlighted, assessing effective therapeutic strategies to increase socialization with depressed individuals and to decrease psychological stress. [Preview Abstract] |
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F01.00030: Wonder Girls Camp: A Virtual Physics Camp for Middle School Girls in the Pandemic Kayla Dickert, Dan Fauni, Gianna Calligy, Keeran Ramanathan, Roberto Ramos h $-abstract-$\backslash $pardThis year was the ninth year of The Physics Wonder Girls Camp. Due to conditions from the COVID-19 Pandemic, the camp had to be held virtually. We will explore our experience in planning, organizing, and execute this program. Our goal is to provide immersive experiences to diverse groups of middle school girls chosen for their high-performance academically in the Philadelphia-New Jersey area. The theme for 2021 was renewable energies and quantum physics. The campers are introduced to concepts like renewable energy and the basics of solar cells. They are also given opportunities to gain hands-on experience with building projects like solar cars and solar boats and perform optics experiments. To wrap up each cohort, the campers gave capstone presentations showing off what they learned and improving their presentation skills. The materials for projects and experiments were provided to the campers for free. The campers had the chance to interact with physics majors who worked as camp crew, successful women physics and engineers, and experience virtual tours that explored plants and manufacturing facilities.$\backslash $pard$\backslash $pard-/abstract-$\backslash $\tex [Preview Abstract] |
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