Bulletin of the American Physical Society
Joint Spring 2013 Meeting of the Texas Sections of the APS and AAPT and Zone 13 of the SPS
Volume 58, Number 3
Thursday–Saturday, April 4–6, 2013; Stephenville, Texas
Session K1: SPS Poster Session (4:00 - 5:00PM) |
Hide Abstracts |
Chair: Chris Marble, Tarleton State University Room: Science Building 2nd Floor |
|
K1.00001: Designing and Building a Tabletop Molecular Acoustics Experiment Ashley Hicks, William Slaton This work describes the design, construction, and testing a project investigating the molecular absorption of sound in certain gases, including the development of a capacitance transducer. The transducer is based on designs presented in the literature, modified to work optimally in our system which consists of 4-inch diameter steel pipe. The experiments will be conducted at atmospheric pressure, eliminating design constraints involved when using high pressure gas. However, work done by Bass {\&} Shields shows that to work in these experiments at atmospheric pressure, the transducer must have a frequency range of 1 kHz -- 100 kHz. [J. Acoust. Soc. Am. Vol 62, p. 346-353, 1977] The basic concept of our transducer depends upon creating a parallel plate capacitor from metal that is flexible enough to move when a sound wave hits it. Our design utilizes 0.051 mm thickness aluminized Mylar film tensioned with a brass retaining ring over a brass backing plate with both secured to a Delrin plastic base for its electrically insulating properties. We will report on the transducer's performance and initial testing in a sound absorption experiment with carbon dioxide. [Preview Abstract] |
|
K1.00002: Controlled Drug Delivery from Therapeutic Contact Lenses: the need for Accurate Release Studies Payam Pourjavad This work demonstrates the detrimental effects of inconsistency in release studies conducted in the field of controlled drug delivery via therapeutic contact lenses. It also express how certain condition can lead to false representation of a supposed controlled release. The lack of a standard in the field hinders the progression of effective methods and creates a distrust for all drug delivery systems from contact lenses. In vitro release condition variables include volume, mixing rate, temperature, solvent, and elapsed time between water exchange. The solubility of the drug being controlled is also a factor. Addressing solubility we created three different molecularly imprinted polymer networks that were designed to control three different drugs, Ketotifen Fumarate, Diclofenac Sodium, and Dexamethasone. It is clear that the different variables seen in the conditions have a huge impact on the release profiles, and that a condition is need to make valid comparisons amongst different drug delivery techniques. [Preview Abstract] |
|
K1.00003: An Analysis of the Texas Physics Teaching Certification from 2007-2011 Kristin Holz I researched pathways to teaching certification under the advisement of Dr. Jess Dowdy of the Abilene Christian University Physics Department. His goal is to observe trends in the data from the state certification database providing information about physics teaching certification in Texas over the last four years. This research centers on the state certification database of information about teaching certification in Texas over the last four years. Within this database, I looked at various types of physics teaching certification tests taken by students from different universities during the years of 2007 through 2011 in order to focus on relationships between various aspects of the state data. I aided in coding this data to organize the information and quantitatively measure certain relationships. I also researched supplemental data to expand my analysis. My hypotheses were developed by searching the literature to incorporate other research performed on Texas physics teaching certification. [Preview Abstract] |
|
K1.00004: Absorption Properties of NASA Flight Approved Materials and other Testable Samples Matthew Sisson, Justin Mann, William V. Slaton The purpose of this project is to analyze the acoustic absorption properties of various flight approved materials currently and potentially used by NASA in its work with the International Space Station. These materials, consisting of manufactured felts and foams, were used in an experimental procedure utilizing an impedance tube. By simultaneously measuring the forward and backward components of generated plane waves within the tube, sound absorption coefficients were obtained for over 30 specific materials. Understanding these absorption properties can lead into the discussion of how to specifically arrange and utilize the materials to both maximize efficiency based upon a material's density and minimize excess ambient noise on manned space vehicles. These possible applications not only potentially affect astronauts on current and future missions for NASA but can also be directed in situations involving the choice of materials in auditoriums, concert halls, classrooms, etc. [Preview Abstract] |
|
K1.00005: Electronic structure of dye attached fullerenes Amanda Garnica, Rajendra Zope, Tunna Baruah C$_{60}$ fullerene and its derivatives are the most popular acceptors which are used in molecular/polymeric complexes used in organic photovoltaics. Recently, Chabynic et al. have synthesized a few functionalized C60 molecules with dye molecules for use as acceptors in solar cells. The functional units are diketopyrrolo-pyrrole and TBTDT pigments. Using density functional theory and large polarized all electron Gaussian basis, we optimized the structures of the C60-DPP and C60-TBTDT molecules. The inspections of molecular orbitals of these systems indicate that the HOMO level is localized on the dye whereas the LUMO is on the C60 molecule. We have also calculated several lowest CT excited states where the charge transfer takes place from the HOMO on the dye to the LUMO on the C60 molecule. The electronic structure of the ground and the excited states will be presented. [Preview Abstract] |
|
K1.00006: Design and Testing of a Custom Air Horn Jerrod Ward, William V. Slaton Construction and testing of an air horn can provide insight into how certain design decisions can influence resulting acoustic properties. The unique sound of the air horn is produced when compressed air enters the main chamber through an inlet and builds up pressure against the diaphragm. As pressure builds, this diaphragm flexes to allow the air to leave the chamber through the outlet which is flush against it. This relieves the pressure in the chamber and the diaphragm returns to its original position, slamming against the outlet, creating the signature sound. We have designed and manufactured an air horn where it is possible to vary many different experimental parameters such as nozzle length, outlet diameter, diaphragm material, diaphragm thickness, diaphragm tension, etc. In this study, we have focused on the properties of the diaphragm and their relationship with the air pressure. By trying different permutations of diaphragms and seals with a range of pressures, it is possible to produce a desired tone over a very large range of frequencies. The system is very delicate and things like a good gasket seal for the diaphragm and solid, flush connections between the outlet and the diaphragm are absolutely necessary to ensure that pressure builds and relieves itself appropriately. [Preview Abstract] |
|
K1.00007: Alternative Visualization Methods of Wine Glass Resonance Shelby Burns, William Slaton Breaking a wine glass with sound is a visually striking achievement and a great way to get potential students interested in Physics. The goal of this project is to not only break the wine glass but to build an apparatus that is portable and easily setup for lecture room demonstrations as well as outreach. The apparatus should also provide enough visibility for a room full of observers to easily see the resonance. Thus we constructed an enclosure using clear plexiglass, attached to two compression driver, hooked up to an amplifier and then hooked up to a signal generator. Until now our experiment has only been approached from one angle which is the utilization of a strobe light apparatus as the way to view the different modes of the wine glass. Moving forward with the experiment we began to explore different ways of viewing the modes of the wine glass. After receiving a generous loan from University of Mississippi in the form of a high speed camera, it is now possible to capture the modes without the use of a high speed strobe light. The apparatus should also provide even better visibility than previously achieved for a room full of observers to easily see the resonance. In a larger setting a camera could be used to relay the relatively small image of the wine glass to a projector for better visibility, only now there is a possibility to enhance the quality of those pictures and videos. From a more technical stand point, the project will provide an opportunity to experiment with resonance on a variety of different capture methods. In order to prepare for the final demonstration, many different wineglasses will be tested in the test chamber as well as different capture methods [Preview Abstract] |
|
K1.00008: Analysis of Atomic Emission Spectra: a refined way to understand the photon concept Sara-jeanne Vogler, Keeley Townley-Smith, Cristian Bahrim Spectroscopic analysis of atoms and simple molecules reveals the atomic structure, the emission of photons, and the quantum interaction between light and matter. The optics equipment allows us to resolve the emission lines with a precision better than 1 nm. Pressure broadening effect enlarges the emission lines of our light sources to several nm at FWHM. From the relative intensity of the emission lines, de-convoluted using the Maxwell- Boltzmann distribution of atoms in a gaseous discharge at thermal equilibrium, we can find the effective temperature of the atoms and their average speed. Pressure broadening reveals the quantum characteristics of the photon emission by including the uncertainty principle. From the Lorentzian profile of each photon one can find the lifetime of the atomic states in given experimental conditions, and by comparison with their natural lifetime, the effect of the collisional de-excitation can be estimated. Because the photon emission obeys the selection rules for orbital angular momentum, spin, and parity, one can identify the characteristic wavelengths of the atomic constituents of light sources. We are going to present a brief progress report on the applications of the spectroscopic analysis in stellar measurements done under our 2013 Sigma Pi Sigma Undergraduate Research Award. [Preview Abstract] |
|
K1.00009: Dynamic Optimization on the Eigenvalue Problems Katherine Oh, Richard Kyung In many fields of mathematical and physical science, the concept of optimization has been used to make better decisions for complicated dynamic and mathematical problems. In practice, an objective value to measure the quality of the decision is first defined, and then followed by the selection of a defining numerical algorithm for optimization. In this paper, the main focus will be on numerical optimization algorithms on the eigenvalue problems in the modal analysis. In general, one cannot obtain exact closed-form solutions using classical mathematics for the desired optimal eigenvalues in the case of generalized eigenvalue problems. Therefore, to find the desired dynamic characteristics, using a numerical iteration method for optimization is the only practical alternative. In this paper, we have developed a numerical optimization algorithms. The proposed algorithm shows practical usefulness and can solve the problems using much less degrees of freedom of a system. [Preview Abstract] |
|
K1.00010: Understanding the Dielectric Response of Polar Organic Solvent in an Artificial Photosynthetic System Francis de Dios The artificial photosynthetic analogue of interest is the triad molecule composed of an organic material in fullerene (C60), and two naturally occurring compounds: porphyrin and carotene. The components of the triad are abundant in nature and the cost of its synthesis is very small relative to the expense of fabrication of inorganic solar cells. Combining the economic advantages of the triad with its ability to mimic the natural photosynthetic process, the triad promises to be a feasible basis for highly cost-effective solar energy conversion. The present work focused on the behavior of solvent molecules in the presence of both a ground state and excited state triad molecule. The solvent significantly influences the structural fluctuations of the triad and increases the lifetime of the photo-induced charge-separated state of the triad by providing an electrostatic-screening effect. The two types of organic solvents that were investigated were Tetrahydrofuran (THF), which is a polar molecule, and Toluene, which is non-polar. Reduced radial shells of the solvent were taken to observe significant large-scale variations in the dielectric constant.The results from the dielectric constant evaluation suggest a much stronger interaction between the THF solvent and the triad compared to the interaction between Toluene and the triad due to the significantly larger dipole moment of THF relative to that of Toluene. Furthermore, the interaction is very large between THF and the charge-separated excited state of the triad, meaning that the magnitude of interaction between the solvent and the triad is largely dependent on the electronic state of the triad and the dipole strength of the solvent molecules. The spatial correlations between selected solvent molecules were also analyzed to gain further insight on the solvent fluctuations. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700