Bulletin of the American Physical Society
2021 Joint Spring Meeting of the Texas Sections of APS, AAPT and Zone 13 of the SPS
Volume 66, Number 2
Thursday–Sunday, April 8–11, 2021; Virtual
Session A08: APS: Applied Physics and Engineering-II |
Hide Abstracts |
Thursday, April 8, 2021 6:00PM - 6:12PM |
A08.00001: Compound Bow Efficiency Joseph Watson The goal of this project was to determine what affects the efficiency of a compound bow. Some general factors could have been draw weight, draw length, cam shape, let-off percentage, arrow weight, arrow spine, and string silencers. The efficiency of a compound bow was measured using several sets of variables and constants to determine relationships for these efficiency factors. It was discovered that draw length and arrow spine do not affect efficiency. Efficiency increases with increased arrow weight, and increases as a bow approaches its peak draw weight. Efficiency decreases as string silencers, or generally speaking weight is added to a bow's string. [Preview Abstract] |
Thursday, April 8, 2021 6:12PM - 6:24PM |
A08.00002: Solar Cells Stability at Vibrations and Temperature Gradients Daniel Quispe, Cristian Bahrim Our analysis of solar cells' response to its orientation, mechanical stability, and temperature variations will be reported. Most of our indoor experiments are done with a thermal light source located at one-foot distance from a commercial silicon-based PASCO solar cell, model SE-8847 of 1W. Our studies reveal that the solar cell receives irradiance from this light source which follows an inverse square law dependence. This allows us to extrapolate our results for any distance from 8 inches to 6 feet. First, we report the stability cone of the solar cell, which is about 15 degrees from the normal to the cell's surface. Next, we measure the impact of thermal change on the cell's surface due to the incident radiation from the thermal source and notice a drop of 11{\%} in the photo-voltage production for an increase by 27{\%} in cell's surface temperature (from 22 to 28 Celsius). Such drop can be recovered with air blowers orientated at grazing incidence. From the characteristic curve, we measure the resistance of the solar cell and observe that is temperature independent. In fact, the photo-voltage and photo-current of the solar cell vary in sinc with the change in temperature. We also report studies of photo-voltage production with the mechanical stability due to air blowers oriented toward the surface within the stability cone, as well as using a PASCO Mechanical Wave Driver controlled by Sine Wave Generator. We notice that within 15 Hz about the resonant frequency of the solar cell-supporting platform system, the photo-voltage has a parabolic variation with a minimum at a value 15{\%} below the nominal photo-voltage value in the absence of vibrations. [Preview Abstract] |
Thursday, April 8, 2021 6:24PM - 6:36PM |
A08.00003: The objective view of Fukushima as clear support and driving motivation for nuclear energy despite radiophobia Robert Hayes The UN did not only arrange the IPCC which advocated for nuclear energy, it also convened a diverse expert working group on the health effects from the cumulative Fukushima radioactivity release. This latter expert panel (UNSCEAR, \underline {https://www.unscear.org/docs/reports/2013/14-06336\textunderscore Report\textunderscore 2013\textunderscore Annex\textunderscore A\textunderscore Ebook\textunderscore website.pdf}) found that no measurable medical effects are expected from all the radiation doses to the Japanese population in general (and even less so elsewhere) due to its engineered safety designs such as its intentional containment. The word ``Fukushima'' is almost a terror phrase along with nuclear waste and nuclear energy in general despite a litany of consistently out-producing safety metrics including the worst case Fukushima event for western designs. The WHO (\underline {https://www.who.int/news-room/q-a-detail/health-consequences-of-fukushima-nuclear-accident}) also confirmed these findings along with relevant professional society assessments and most striking of all, the only real measurable effects are fear based stress outcomes from radiation doses that are comparable or less than natural background radiation. This radiophobia was found to incite a prolonged stress effect in an almost curse like belief system from being exposed to low levels of radiation. Issues such as nuclear waste, transportation safety and other nuclear accidents will also be considered in this talk. [Preview Abstract] |
Thursday, April 8, 2021 6:36PM - 6:48PM |
A08.00004: Effects of laser defocusing on intermediate species during energy deposition Sagar Pokharel During dual pulse laser energy addition, when plasma is already present in the focal area, the remainder of the laser pulse is partially reflected causing a different spatial distribution of laser intensity profile compared with the Gaussian profile (defocusing). This study reports on the effects of defocusing during laser energy deposition in hydrogen-air mixture. Three temperature plasma model coupled with Navier-Stokes equation and an independent beam propagation solver to quantify intensity of laser during defocusing are used for the two-dimensional numerical simulations. The results show that the effects of defocusing are more pronounced in long lived species like H2O2 than the short-lived species like O, OH. [Preview Abstract] |
Thursday, April 8, 2021 6:48PM - 7:00PM |
A08.00005: Arduino based Implementation of a Closed-Feedback Control Loop in a Magnetic Levitation Device Roel Olvera II, Toni Sauncy Magnetic levitation (MagLev) systems provide a fun and engaging way to explore upper-level digital electronics, learn more about control systems, and apply fundamental principles from electrodynamic courses. The MagLev system suspends a neodymium magnet (which can be attached to any object) using a linear hall effect sensor that is set to control the strength of an electromagnet, orchestrated using a low-cost Arduino uno. Construction of the MagLev system has provided an opportunity for strengthening essential skills including coding, electronics design and circuit construction, and basic carpentry skills. The materials and construction of similar devices often prove to be expensive. In this project, a MagLev digital system was designed and built using low-cost materials and scrap wood. A manual for use by future students will allow the device to be used in undergraduate labs and courses to challenge students to find ways to improve on the basic feedback loop system and build their own apparatus. Possible improvements may arise in the form of a digital to analog system, a stronger, cheaper structure, or the addition of different sensors to improve the quality of the feedback loop for more precise positioning of the levitated object. [Preview Abstract] |
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