Bulletin of the American Physical Society
2018 Annual Meeting of the APS Four Corners Section
Volume 63, Number 16
Friday–Saturday, October 12–13, 2018; University of Utah, Salt Lake City, Utah
Session J01: General Physics |
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Chair: Andrea Palounek, Los Alamos National Laboratory Room: JFB 101 |
Saturday, October 13, 2018 8:00AM - 8:12AM |
J01.00001: Giant Carbon Fullerenes for Target Specific Drug Delivery Boris Kiefer Nanoscience and nanotechnology continue to revolutionize our ability to control and harness material properties at the nanoscale. Fullerenes, hollow shapes of carbon atoms, attract significant attention since these shapes can serve as protective containers for cargo. It is attractive to envision biomedical applications where a drug is protected by the fullerene and released when the target is reached. However, several challenges must be met before this concept can be transformed from vision to reality. Among these challenges are, solubility, carbon-carbon bond breaking, and a triggering mechanism. Here we investigate the potential of giant closed carbon shells for drug delivery with atomistic simulations using classical force fields. We functionalize giant fullerenes with OH groups to increases the solubility of the carbon hulls in polar solvents such as blood. Our preliminary results show that OH groups weaken bonds and thereby facilitate bond breaking, Simultaneously, OH functionalization is pH sensitive and can be used as a sensing and triggering mechanism for drug release. Our preliminary results suggest that that the shear motion in a solvent may be sufficient to rupture the fullerenes quickly and to release the drug in the targeted area. |
Saturday, October 13, 2018 8:12AM - 8:24AM |
J01.00002: Strain-Induced Raman Shifts Due to Ice Adhesion Subash Kattel, Joseph R. Murphy, Samuel R. Pasco, Vladimir Alvarado, William D. Rice When ice is formed on a material, it creates a strain proportional to the adhesive strength between the ice and substrate. In order to quantify this adhesion, we use Raman spectroscopy to measure the vibrational modes of various materials with and without ice. To isolate the ice-material interface, we performed Raman spectroscopy on single-layer graphene from 20 °C to - 30 °C with and without ice. Along with the well-known temperature-dependent Raman shift of graphene, a clear, ~ 3 cm-1 shift in the G-mode (~1590 cm-1) developed when the ice formed. We found this Raman shift tracked closely to the temperature-dependent density of ice, suggesting that we are optically measuring ice-created strain on graphene. |
Saturday, October 13, 2018 8:24AM - 8:36AM |
J01.00003: Correlation Between Sound Pressure and Fluid Flow of Vacuum-Assisted Toilets Mark Anderson, Michael Rose, Kent L Gee, Scott Sommerfeldt, Zachary Jones, Dagan Pielstick Vacuum-assisted toilets are used in commercial aircraft and come with an unwanted stigma of being uncomfortable and loud. A quieter toilet design has been developed by modifying the waste tube geometry. The goal of this work is to understand quantitatively how this tube geometry modification to a vacuum-assisted toilet reduced its radiated noise. To better understand the noise reduction obtained using the modified waste tube, high-speed video of the flow passing through clear tubes of the same geometry has been recorded and analyzed. An open source Particle Image Velocimetry (PIV) MATLAB code called OpenPIV has been used to determine both the direction and speed of the flow. Correlations between the flow field and the noise reduction for the modified tube geometry will be shown. |
Saturday, October 13, 2018 8:36AM - 8:48AM |
J01.00004: The Physics behind Vacuum-Assisted Toilet Noise Reduction Zachary Jones, Mark Anderson, Michael Rose, Dagan Pielstick, Scott Sommerfeldt, Kent L Gee, Scott Thomson Using the restroom on an airplane is considered by passengers to be an extremely uncomfortable experience because of the high noise levels generated during a flush. A modified toilet has been designed and is shown to reduce the A-weighted overall sound pressure level by 15 dB. The purpose of current research is to better understand the physics behind this sound pressure level reduction by taking sound pressure measurements along the tube using 26 three-dimensionally printed microphone holders to look for the presence of evanescent decay from the opening of the toilet valve to the toilet bowl. Results will be presented and discussed during the presentation. |
Saturday, October 13, 2018 8:48AM - 9:00AM |
J01.00005: Measuring directionality of small-scale explosions Menley S. Hawkes, Julio Escobedo, Grace McKay Volcanic explosions produce infrasound that contains clues to the strength of the explosion and the amount of debris ejected. Scale-model explosions can be used to learn more about how to interpret volcano infrasound. Our goal was to explode oxyacetylene balloons placed in specially designed craters. The influence of the crater design on the sound levels was investigated. Several components were required for a successful test. The meteorological conditions were monitored. Acoustic recordings required a careful and accurate setup of research grade microphones and high-speed data acquisition system. The microphones were placed in a circular array, with 20 m radius, concentric with the crater. Explosive balloons were filled with stoichiometric mixtures that provided acoustic shocks with frequencies down into the infrasound spectrum. Two successful measurements were obtained for four crater morphologies. In analysis of peak sound level and sound exposure level polar plots, we were able to see that directionality of the acoustic shock was achieved in one crater. |
Saturday, October 13, 2018 9:00AM - 9:12AM |
J01.00006: Exploring How to Accelerate Materials Discovery through PAO Representation Nathan L Foulk, Jeremy J. Jorgensen, Gus L. W. Hart To discover the materials that will shape the world of tomorrow, we need to make the materials calculations of today more efficient. Solving the electronic band energy is one of the most important parts of these materials calculations, which are typically performed using a plane wave basis. Unfortunately, such a plane wave basis requires a very large number of basis functions, which makes the computation extremely expensive. We explore potential speedups of the calculation of the electronic band energy by representing our wavefunctions in a new basis of Pseudo Atomic Orbitals (PAO). |
Saturday, October 13, 2018 9:12AM - 9:24AM |
J01.00007: Accelerating the discovery of materials Jeremy Jorgensen, Gus Hart The government-sponsored Materials Genome Initiative demonstrates the importance of accelerating the discovery of materials, the impact of which would be felt in all technology disciplines. The high throughput approach to materials discovery takes advantage of high-volume computing and advances in machine learning to increase the accuracy and efficiency of material prediction. The current bottleneck to the high-throughput approach is the computation of large, theoretical databases of materials, the limiting factor being the slow convergence of a difficult numerical integral. We explain the hidden complexities of this unusual numerical problem and our approach to increasing its rate of convergence. Our tests on realistic 2D models show a ten-fold increase in computational efficiency over the traditional approach. |
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