Bulletin of the American Physical Society
80th Annual Meeting of the APS Southeastern Section
Volume 58, Number 17
Wednesday–Saturday, November 20–23, 2013; Bowling Green, Kentucky
Session KA: Poster Session |
Hide Abstracts |
Room: Hallway |
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KA.00001: Evaluation of Quasi-Molecules for collision studies at low energies Dwayne Joseph, Bidhan Saha Slow collisions involving ions and atoms or molecules has wide application from astro to plasma physics [1] and require special attention for obtaining accurate information regarding its structure and interactions. At low velocities the projectile can reach the close vicinity of the target for forming a quasi-molecule. The accurate determination of its eigenvalues and eigenfuctions poses difficulties when the internuclear separation becomes less than 1 bohr. We report the details of our recent study on (SiH)3$+$ quasi-molecule using the multi-reference single- and double-excitation configuration interaction (MRD-CI) method [2]. \\[4pt] [1] B.H. Bransden amd M.R.C. McDowell. Charge Exchange and the Theory of Ion-Atom Collisions(Clarendon Press, Oxford, 1992).\\[0pt] [2] R. J. Buenker, Current Aspects of Quantum Chemistry 1981, Vol \textbf{21}, edited by R. Carbo (Elsevier, Amsterdam) p 17. [Preview Abstract] |
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KA.00002: Geolocation Analysis and Social Median Data Acquisition via Twitter Content Christopher Wright, Lance Hahn, Phil Womble, Keith Andrew The rapidly expanding usage of social media websites such as Twitter, make is possible to use robust statistical inquires to construct a geolocation analysis of an individual account using the content of tweets. Within this context we expand upon the earlier research of Zhiyuan Cheng done in 2010 where he was able to detect the location of a Twitter user within 100 miles of their actual location 51{\%} of the time. In 2010, Twitter had approximately 75 million unique users registered but by March 2013 Twitter had grown to nearly 500 million unique users. Here we gather Twitter data from a custom dataset and use specially designed Excel macros and search engines to calculate goelocation probabilities on the new user population. Our method centers on nearly unique word usage and semantic structures that have evolved for regional users as identified in detailed linguistic recognition studies. Improvements in efficiency, convergence and accuracy of social media geolocation information can significantly impact threat measures utilized by the Department of Homeland Security and U.S. Cyber Threat Task Force. [Preview Abstract] |
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KA.00003: Storm Activities and Impacts in the Western Arctic Marginal Ice Zone Wei Tao, Jing Zhang, Xiangdong Zhang Long-term changes in weather patterns and surface winds have been detected over the Chukchi-Beaufort Seas through the use of the newly-developed Chukchi-Beaufort High-Resolution Atmospheric Reanalysis (CBHAR). Embedded within these long-term changes, it has been noted that storm frequently invaded Western Arctic marginal ice zone. To understand the physical mechanisms and impacts of these storms, we have investigated two particularly unusual storms in this study. The first storm occurred during 23-30 September 2010, showing unusual persistence and lingering over the Beaufort Sea for more than five days. The other occurred during 2-13 August 2012, exhibiting extremely strong intensity with a minimum central surface pressure of 964 hPa on 6 August. The presence of the former storm resulted in persistent northerly winds that favored a southward extension of the ice edge, resulting in enhanced sea ice coverage in the Northern Beaufort Sea. The wind pattern associated with the August storm brought southwest winds into the Beaufort Sea, an anomalous wind pattern that enhanced warm air transport into the area and contributed to a rapid retreat of sea ice cover. [Preview Abstract] |
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KA.00004: In-situ Investigations of the Surface Microstructure Evolution of Metallic Specimens Using the Large Chamber Scanning Electron Microscope at Western Kentucky University Grace Egbujor, Edward Kintzel An initial study into the use of the large chamber scanning electron microscope (LC-SEM) to interrogate the surface microstructure evolution of metallic specimens has been carried out. The LC-SEM located at Western Kentucky University is the largest instrument of its type at any university in the world. As such, unique measurements can be performed due to the size of its chamber and extended view of its optic system. Strain was varied for each individual specimen, and imaged using a combination of Backscattered Electrons and a Focused Ion Beam within the gauge length as well as near the grip position. Results will demonstrate the capability of the LC-SEM to carry out these types of measurements. Future measurements will include the incorporation of a in-situ uniaxial load frame for dynamic studies. [Preview Abstract] |
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KA.00005: Deterministic and other Methods Available to Solve the Maxwell-Boltzmann Transport Equation for Particles Scattered off of a Broad Slab with Thickness `L' Eric Steinfelds, Keith Andrew Although the discussion and formulations shall be of a theoretical nature, it is intended that computations of solutions for the Maxwell Boltzmann (M.B.) transport equation be applied to benchmarks in nuclear engineering, simple (but not trivial) examples in medical physics, and even the scattering of light off of planetary surfaces. One can find planetary examples and theoretical inspiration from the text ``Radiative Transfer'' (\copyright 1950) by S. Chandrasekhar. The presentation shall start from the M.B. transport equation, proceed with mathematical methods to the corresponding integral equation, and continue with an iterative method for predicting the scattering of neutral particles off of a broad slab of material (with Tk$=$`L'), where slab is in vacuum. The incoming beam need not be at the right angle. Chandrasekhar came up with the H-function to generate the solutions of scattered particles as a function of angle for a slab of infinite thickness. The analysis presented by the author shall be oriented to calculations of the particulate `flux' within and off of a finite slab target. It will be presumed that the particles in the slab are isotropic scatterers, but the albedo (or 1$-$absorptiveness) are anywhere form 0 to 1.0. Results for the simulation of angles of escape might be shown. [Preview Abstract] |
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KA.00006: External Morphology of Circumocular Structure on a Cambrian Trilobite Fossil with SEM Energy Dispersive Spectroscopy Compared to Proetidia Members Kristopher Andrew, Keith Andrew, Karla Andrew, Edward Kintzel The identification and characterization of certain fossils is considerably enhanced by using both optical microscopy and scanning electron microscopy coupled with electron backscatter techniques. Using the Large Chamber Scanning Electron Microscope (LC-SEM) at Western Kentucky University's Nondestructive Analysis (NOVA) Center we are performing a detailed surface morphology and elemental abundance study of the circumocular region resolving the holochroal region along with a simultaneous optical study. Backscatter electron imaging is used to obtain high resolution compositional maps of the samples allowing for a method that distinguishes between different material phases. We find using multiple methods allows us to better characterize the specimens, in particular we find that a Cambrian arthropod Trilobite is rendered with BSE details from the cephalon, thorax, pygidium and left pleural lobe regions allowing for improved placement in the Order Proetida and an analysis of the circumocular region allows for modeling the primitive structure. [Preview Abstract] |
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KA.00007: Analysis of coating characteristics of thin-film system David Didie, Daniel Didie, Sushovit Adhikari, Sanichiro Yoshida Our previously developed opto-acoustic technique has been applied to evaluate the adhesion strength of thin-film coating on silicon-wafers. The goal of this research is to evaluate the effectiveness of pre-coating surface treatments on the substrate. We configure a Michelson interferometer with the thin-film surface of the specimen acting as an end-mirror, and oscillate the specimen from the rear with an acoustic transducer sweeping the driving frequencies in a range of 500 Hz to 30 kHz. One of the interferometric arms is slightly tilted so that the interferometric fringe pattern observed behind the beam splitter consists of vertical darks stripes. Here, the fringe contrast varies depending on the relative motion of the film surface to the substrate. This allows us to analyze harmonic response of the film, and thereby find resonance-like behavior of the interface. One emerging area for application of this type of thin-film systems is artificial knee joints. We are particularly interested in harmonic response of the film surface at low frequency ranges where human knee motions dominate in various modes of activity. [Preview Abstract] |
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KA.00008: Analysis of Fiber Structure in a Concrete Matrix from EBS Coupled to Raman Spectra Keith Andrew, Shane Palmquest, Edward Kintzel, Aaron Celestian, Gregory Arbuckle, Jahi Palmer Fibers at the mirco and nano scales have been added to concrete for many years to help control and design the mechanical and structural properties of the underlying material. Such specialty fibers may result in cementitious materials that are more durable, flexible, stronger, less permeable, and ``crack free'' than traditional concrete. Using the combined power of Electron Backscatter methods coupled to Raman Spectroscopy we examine a series of cast specimens that contain microfibers and carbon nanotube fibers, CNTs. We detail the surface morphology of regions near failure zones and analyze the failure strain rates for samples with different mixture ratios. A detailed interpretation of the underlying chemical bonding structure is added to the analysis from Raman spectroscopy applied to the samples. These results provide a greater understanding on the nature of the interfacial transition zone, ITZ, between the cement and paste and the aggregates. [Preview Abstract] |
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KA.00009: Controlled Growth of Ultrathin Copper Phthalocyanine Films Adsorbed onto Glass Substrates Jesse Finley, Edward Kintzel, Detlef-M Smilgies Considerable technological interest in solar energy and other applications have been directed toward understanding the structural properties of single-crystalline organic materials as the performance of molecular electronics devices is pushed to new limits. Initial investigations of the growth of ultrathin copper phthalocyanine (CuPc) films vapor deposited onto glass substrates have been carried out. Individual glass substrates were maintained at discrete temperatures in the range 25 - 200 $^{\circ}$C, in 25 $^{\circ}$C increments. At each temperature, film thickness was varied in the range 0.5 -- 20 {\AA}. Previous x-ray diffraction (XRD) studies indicated substrate temperature was not factor in the molecular orientations within adsorbed film. In the current investigation, we will build on these initial results to include film thickness at each temperature, as indicated. Real-space imaging using atomic force microscopy will be used to compared to the XRD results. [Preview Abstract] |
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KA.00010: Design {\&} Testing of Magnetic Field for 2.45 GHz Compact ECR Ion Source Shankar Nair This paper describes the theory, design and 3D simulation of the magnetic field for a 2.45 GHz ECR ion source to be fabricated at the Bhabha Atomic Research Center (BARC), India. One Tesla NdFeB permanent sector magnets are to be used in ring configuration to achieve the desired axial field for resonance condition. A verification of the software used for finite element analysis (CST particle studio) was done by comparing the experimental results with that of the software for a 12- sided polygonal structure embedded with 0.6 Tesla NdFeB permanent magnets. The axial magnetic field results (B$_{z})$ of both methods follow the same general trend with a percentage error of 3.55{\%} in the B $_{peak}$ value. [Preview Abstract] |
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KA.00011: Noise Reduction Techniques for Analyzing Electrochemical Systems Keenan Stone, Roger Kisner The ionic noise, emanating from electrochemical reactions, possesses distinct properties that are thought to be indicative of underlying chemical and physical processes. Such Electrochemical Noise (EN) is difficult to differentiate from ambient noise from one's own surroundings and measurement equipment. Many techniques exist that aid in reducing both external and equipment noise, which may involve either data analysis/acquisition methods or the physical alteration of an experimental apparatus. We present measurements of the EN, having implemented several noise reduction techniques, conducted with a setup design intended for use in other research at Oak Ridge National Laboratory. [Preview Abstract] |
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KA.00012: Analysis of residual stress using ESPI Saugat Ghimire, Sean Craft, Sanichiro Yoshida Residual stress exists within a material in the absence of external forces and arises from various manufacturing processes. The material under consideration is a welded metal sample consisting of two metals (stainless steel and carbon steel). The cause of residual stress in this case is the fact that the two metals, when cooled down after the welding process, contract at different rates due to the relative difference in their coefficient of linear expansion. We use dual beam Electronic Speckle-Pattern Interferometry (ESPI). It involves applying tensile forces on the welded sample, and subtracting the sample image taken before the application of the force from taken after; this forms the so-call fringe pattern that represents the deformation map of the entire sample. Our method of analysis is based on the following hypothesis: The stiffness of materials is known to depend on stress. If a static load is applied to a welded sample, applied force will be uniform for the entire specimen. Therefore, residually-stressed parts of the specimen should respond to the uniform force differently from non-residually stressed parts. This difference can be revealed as non-uniformity on the corresponding ESPI fringe pattern. [Preview Abstract] |
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KA.00013: Laser Induced Breakdown Spectroscopy for Monitoring Trace Elements in Liquid Samples Prakash Sharma, Alejandra Sandoval, Akshaya Kumar Laser Induced breakdown spectroscopy is a developing and promising technology of the coming era due to its simplicity and robustness. A high energy pulsed ND: YAG laser light is focused on the sample using lens to create plasma of the sample material. The plasma of the sample emits light during its cooling process. The optical light emitted from the plasma is collected by optical fibers and send to the spectrometer for spectral analysis. Various elements present in the sample have their characteristic emission wavelength signatures. The intensity of emission is captured by a CCD array detector and displayed on the computer. We have employed the LIBS technique to identify the trace elements in water. Various sample conditions and experimental parameters such as time delay between the laser pulse and detection device known as time delay has been changed to see its effect on LIBS signal. This technique can be used for real time monitoring of water quality. [Preview Abstract] |
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KA.00014: Fabrication of ZnO Nanostructure Based Polyvinylidene Fluoride Nanocomposites for Energy Application Sarah Pak, Brigham Mu, Anthony Mayo, Jennifer Jones, Richard Mu, Eugene Collins Zero- and one- dimensional nanostructures process many unique physical and chemical properties. With the advanced nanotechnology and computational capability, it is now possible to produce artificial and sophisticated nanostructures and systems beyond what nature can provide. The structure-by-design with bottom-up approach is expected to be the game changer but requires technological breakthroughs in many fronts. ZnO nanoparticles (NPs) and nanowires (NWs) have shown to have a broad applications ranging from optoelectronic, piezotronic, chemical and sensing. Polyvinylidene fluoride (PVDF) is another example of widely used functional crystalline polymers. It is chemical inert, optically transparent, flexible, and ferroelectric. PVDF has four crystalline structures highly dependent on the processing procedures, history, and interactions at molecular level when multicomponent composites are fabricated. Thus, the combined ZnO and PVDF composite may have the potential in ferro-, piezo- and opto-tronic applications. Our preliminary research of ZnO $+$ PVDF nanocomposite has shown a huge optical emission enhancement when ZnO nanostructures are confined in composite form. It is very stable under different environments protected by PVDF matrix. The presentation includes structural and optical characterization, and piezoelectric testing. [Preview Abstract] |
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KA.00015: Supernova 2009nr: A Normal Supernova in the Optical \& Infrared Jonathan Heath, Ginger Bryngelson A type Ia supernova (SN Ia) is a white dwarf (WD) [a dense, electron-degenerate vestige of a star] that has appropriated enough mass from a neighboring star that the total mass of the WD reaches a critical point. The star quickly approaches its mass limit (Chandrasekhar limit) until the overall heat and pressure results in a thermonuclear explosion. A plot of this object's brightness over time is known as a light curve. Because of the uniformity of their light curves, SNe Ia are valuable markers for determining the expansion of the universe and other cosmological parameters. Understanding the properties of these supernovae is vital in order to build our confidence in their use as standard candles. A small, but increasing number of SN Ia late-time observations have been made in the near-infrared (NIR). Most exhibit a flattening of the NIR power even as the visible light declines at a steady rate. It is still unclear as to why they exhibit this behavior and how typical this is. In order to characterize the late behavior of SNe Ia, images of the supernova 2009nr were analyzed using the Image Reduction and Analysis Facility (IRAF). NIR (J, H, K) images were taken with the 4m Mayall Telescope at Kitt Peak National-Observatory using the FLAMINGOS IR Imaging Spectrometer while optical (B, V, R, I) images used the Mosaic 1 imager. The supernova's apparent magnitude for each night of observation (by filter) was found by using reference stars. We present preliminary light curves of the supernova 2009nr and a comparison to another SN Ia observed at similar epochs. [Preview Abstract] |
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KA.00016: Spectroscopic Characterization of White Dwarf Candidates for Calibrating the Dark Energy Survey Mees Fix, Allyn Smith, Douglas Tucker, William Wester The Dark Energy Survey (DES) is a current project in Fermilab's Cosmic Frontier. The DES is a 5000-square-degree optical/near infrared imaging survey conducted over 5 years (2013-2018) for purposes of quantifying the properties of dark energy. Synthetic photometry of pure-hydrogen-atmosphere (``DA'') white dwarfs is currently the preferred technique for determining the absolute zeropoint calibration of large sky surveys. For absolute calibration of the DES we seek to develop a ``Golden Sample'' of 30-100 DA white dwarfs. The starting point is a photometric and spectroscopic observational campaign of $\approx$ 1000 candidate white dwarfs in the DES footprint. Analysing imaging and spectroscopic data will allow us to narrow down this sample. We present results of the analysis of the observing effort. Over 50\% of the observed candidates are to date DA white dwarfs. This portion of the the project was performed as part of the Department of Energy Visiting Faculty Program conducted at the Fermi National Accelerator Laboratory. [Preview Abstract] |
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KA.00017: Photometric Calibrations of Star Fields for the Dark Energy Survey Samuel Wyatt, Douglas Tucker The Dark Energy Survey (DES) is a 5000 deg$^{2}$ grizY imaging survey to be conducted using the new 3 deg$^{2}$ (2.$^{?}$ 2-diameter) wide-field mosaic camera (DECam) on the CTIO Blanco 4-m telescope. The primary scientific goal of the DES is to constrain dark energy cosmological parameters via four complementary methods: galaxy cluster counting, weak lensing, galaxy angular correlations, and Type Ia supernovae, supported by precision photometric redshifts. We present background information on DES, (the method for the program that performs) and aspects of photometric calibrations of star fields to be used in the DES nightly calibrations, and the results received from the script. [Preview Abstract] |
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KA.00018: Status of the Pioneer Anomaly John Hodge Paul ten Boom (arXiv:1307.0537[physics.gen-ph]) suggested the recent publications of the thermal recoil force causing the Pioneer Anomaly (PA) are questionable, suggested a non-sytematic effect is unlikely, and concluded the PA should remain an open issue. Paul ten Boom noted John D. Anderson in a recent interview argued ``\textellipsis that the new analysis has mis--modelled the solar radiation pressure.'' After many years, \textit{only one} model presented to date is consistent with \textit{all} 12 characteristics of the Pioneer Anomaly (Hodge arXiv:0612567v1[astro-ph]) and has predicted later observations (Hodge 2013. IntellectualArchive, 2, 3, p. 1). This proposed model supports a reductive philosophy that no other suggested model does because the model describes the Pound-Rebka experiment and the galaxy redshift of cosmology (Hodge 2006. New Astron., 11, 5, P. 344). Paul ten Boom did not discuss this model. As Paul ten Boom stated ``\textellipsis but ultimately, hard won observational evidence should be a physicist's first priority.'' The PA is a case where conservatism should yield to observation and to a reductive model that explains the observation such as the Hodge model. (http://web.comporium.net/\textasciitilde scjh/ ) [Preview Abstract] |
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KA.00019: Exchange and Magnetic Anisotropic Interactions of Magnetic Ions in Magnetic Materials Alexander Bazhan Investigations of magnetic ions interactions in antiferromagnetic materials, based on theory of crystallographic and magnetic symmetry, which indicates quadratic forms of thermodynamic potentials, invarianted with respect to operations of magnetic symmetry groups and presented in irreducible representations of interacting magnetic moments, are caring out using vector v.s.magnetometer. Magnetic field dependencies of samples three, separate magnetic moments components directly indicate orientations of samples magnetic moments, determined by magnetic ions interactions. Symmetric, Anderson, and antisymmetric, Dzyaloshinskii-Moria, exchange interactions, which are in current interest in studies of antiferromagnetic orders taking into account first-principles methods and models including spin-orbit interactions, in rhombohedral structures as example, H$_{\mathrm{ex}}=\sum_{\mathrm{i,j}}$J$_{\mathrm{i,j}}\cdot $(\textbf{S}$_{\mathrm{i}}$\textbf{S}$_{\mathrm{j}})-\sum _{\mathrm{i,j}}$D$_{\mathrm{i,j,z}}\cdot $(\textbf{S}$_{\mathrm{i,x}}$\textbf{S}$_{\mathrm{j,y}}-$\textbf{S}$_{\mathrm{i,y}}$\textbf{S}$_{\mathrm{j,x}})$, determine weak ferromagnetic states at selected orientations of antiferromagnetic vectors, discussed in the report. [Preview Abstract] |
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KA.00020: The Effects of Substrates, Buffer and Seeding Layers and Thermal Treatments on Zinc Oxide Nanostructure Formation Andrew Trenchard, Richard Mu Zinc Oxide nanostructures have many potential applications due to their wide direct band gap (3.37 eV), large exciton binding energy ($\sim$ 60 meV at room temperature), piezoelectric properties and high electron mobility. A few examples include sensors, transistors and solar cells. Many of these applications could be further enhanced with greater control of the nanostructures being used. Samples are prepared on both Si and SiO$_{2}$ substrates and both with and without the Au layer. Fifty nanometers of SiO$_{2}$ is deposited on the substrate through sputtering deposition, and then 5 nm of Au is deposited with the same method. Next, 20 nm of ZnO is deposited through electron beam deposition. Finally, the samples are then thermally annealed at 700, 750 and 800 C, with some being annealed once for only 30 minutes and others being annealed twice or three times under the same conditions. The samples have been characterized by studying the optical absorbance and photoluminescence, x-ray diffraction and scanning electron microscopy. The experimental results will be discussed under the context of preferential nanostructure formation and crystal orientation due to substrates and thermal treatments. The knowledge obtained from the investigation will give more insight on the future of ZnO nanostructure fabrication and control. [Preview Abstract] |
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KA.00021: Investigating Relaxation in Chalcogenide Using Reverse Monte Carlo Modeling Elizabeth Juelfs, Jordan Taylor, Roman Golovchak, Andriy Kovalskiy, Justin Oelgoetz Non-oxide, chalcogenide glasses (ChG) are composed of a meta-stable network of covalent bonds. Over time, this network relaxes to a more thermodynamically favorable (yet still meta-stable) state, which leads to significant property shifts over time. The mechanism of this relaxation is not well understood. In an effort to illuminate this mechanism, neutron and high energy X-Ray diffraction studies have recently been carried out on glass samples spanning 20 years in age. These studies have been analyzed using a reverse Monte Carlo methodology (RMC). RMC uses structures generated from a random process to produce simulated experimental data, which is then compared to the available experimental data. Structures are kept or rejected based on a probability calculated from the C2 derived by comparing the simulated and experimental data. Statistical analysis can then be carried out on the retained structures. This poster will present the status of that analysis along with what we believe we know about the relaxation mechanism. [Preview Abstract] |
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KA.00022: Development and Optimization of Photocatalytic Air Disinfection System Timothy Powell, Jeremiah Wilson, Lamont Henderson, Sesha Srinivasan, Prakash Sharma Photocatalytic air disinfection (PAD) systems are researched thoroughly towards increasing their maximum efficiency and rate of disinfection processes. Various parameters such as light irradiation, photocatalytic air filter location, gas purging and sampling etc. were optimized via both experimental and theoretical models. Development and optimization of different models are under investigation and will be presented. The objectives of this project are to (a) develop a radiation intensity model to derive the intensity field characteristics in absorbing, reacting, and scattering reaction media in which the rate of the reaction initiation step is expressed as a function of the local volumetric rate of energy absorption (LVREA); (b) develop a model for inactivation of microbes in a filter fiber media using mathematical and experimental data. The ultimate goal of this task is to ensure that the proposed models are true representations of photocatalytic air disinfection. The models developed in this research will be validated with experimental results from a full-scale instrumentation setup in the laboratory. [Preview Abstract] |
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KA.00023: Synthesis and ion exchange studies of porous nano-crystalline materials Aaron Celestian Nanoporous materials have a long and important history in petroleum science. The ion diffusion properties of natural zeolites and their synthetic analogues have been used successfully for catalysis and molecular separation during the petroleum refinement processes. The goal of this research is to understand processes that direct ion diffusion and allow for specific selectivity in heterosilicate titanium/zirconium/niobium silicate, a class of zeolitic analogues. The tools utilized and insights gained into ion diffusion processes will be broadly applicable to other nanoporous materials and will directly benefit energy and petroleum sciences. The goal of this research is to detail the synthesis and cation exchange mechanisms of rare earth elements (REEs: Y, Eu, Gd, Tb) and transition metals (Ni, Cu, Zn) in this suite of nanoporous heterosilicates compounds, and explore new synthetic chemical/structural analogues. [Preview Abstract] |
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KA.00024: Ultrafast dynamics of metallic ErAs nanoparticles embedded in a GaAs matrix Stephanie Gilbert Corder, Norman Tolk Embedded ErAs nanoparticles alter the transport characteristics of the electronic states in the surrounding matrix by introducing localized states into the GaAs bandgap. Utilizing near-infrared pump-probe spectroscopy, we observe two distinct material regimes of carrier relaxation in a time window of less than two picoseconds. The initial transient response is consistent with photo-carriers generated in the GaAs and captured by the ErAs nanoparticles. The capture times are very dependent on photo-carrier density and nanoparticle density; with faster capture times associated with lower densities of both. In addition, we observe the signature of carriers moving from the ErAs interface state in to the GaAs matrix, resulting in larger populations of cool carriers at longer time delays. As of yet, no time-resolved studies have reported carrier transfer back into the GaAs matrix. This transfer of extra carriers due to the presence of the ErAs/GaAs interface state appears to saturate, although further work is needed to conclusively determine the saturation level. [Preview Abstract] |
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KA.00025: Good Vibrations: Plasmon-Exciton Coupling in Gold/Molybdenum Disulfide Hybrid Systems Michael Reynolds, Jed Ziegler, AKM Newaz, Kirill Bolotin, Richard Haglund Monolayer molybdenum disulfide (MoS$_2$) represents a unique platform for investigating the dynamics of exciton-plasmon interactions. We report on a hybrid system composed of Au nanoparticles (NPs) lithographically fabricated on monolayer MoS$_2$ flakes. The NPs are fabricated with dimensions that support plasmonic resonances, which are the optically induced oscillations of the conduction electrons within the metallic NP, in the same spectral region as the MoS$_2$ exciton emission. This hybrid system shows a significant enhancement of the exciton emission as well as a blue-shift in the characteristic exciton peaks. We study the modification of exciton photoluminescence by tuning the resonance of the plasmons around the exciton emission energies. From this geometric tuning, we are able to both tune the enhancement of exciton emission and blue-shift the emission peak. This behavior is distinct from the spectral behavior of the individual MoS$_2$ and plasmonic constituents suggesting a new metamaterial is formed by this hybrid geometry. Our results suggest that the MoS$_2$/plasmon hybrid systems have potential as high efficiency light harvesters, broadband emitters and as tunable visible and NIR photodetectors. [Preview Abstract] |
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KA.00026: Strain-induced second harmonic generation arising from a traveling coherent acoustic phonon pulse measured as a function of depth Joy Garnett, Halina Krzyzanowska, Justin Gregory, Stephanie Gilbert Corder, Jennifer Jones, Zeynab Jarrahi, Norman Tolk Transient second harmonic generation signals and detection of generated coherent longitudinal acoustic phonons are measured simultaneously in reflection from GaSb/GaAs thin layer structures at room temperature using an ultrafast laser pump-probe technique. This proof of concept approach is intended to reveal various surface science phenomena as a function of depth, and is based on the observation that the acoustic strain pulse induces localized changes of electric, acoustic, and optical properties as it propagates through the material. This localized traveling pseudo-interface allows a platform for the depth-dependent study of numerous surface science phenomena. The surface phenomenon of interest in this study is second harmonic generation (SHG). Here, we compare the experimentally observed strain-induced SHG with a theoretical model of the strain influence on SHG which phenomenologically describes the relation between strain and the second order nonlinear optical susceptibility that contributes to SHG. \\[4pt] [1] Y. D. Glinka, N.H. Tolk, J.K. Furdyna, Phys. Rev. B. 84, 153304 (2011). [Preview Abstract] |
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KA.00027: Development and characterization of erbium doped fluorophosphate glasses Jeremy Trimble, Justin Oelgoetz, Andriy Kovalskyy, Carrie Brennan The incorporation of rare earth ions into various glass compositions has led to the development of technologies in recent years such as solid state lasers and optical amplifiers used in high speed telecommunication. Ongoing research in photovoltaic materials science studies compositions of glass films designed to improve silicon solar cell performance by converting unusable parts of the spectrum into photons that match the silicon band gap. Currently, researchers are investigating new compositions of rare earth doped glasses to develop their mechanical and optical properties into new technologies. We investigate tin fluorophosphate glasses doped with erbium compounds for these or other applications. This poster presents our recent work to prepare glass samples for optical analysis and reports the results of fluorescence and Raman spectroscopic measurements. [Preview Abstract] |
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KA.00028: Aging Effects in Hydrogen Storage Characteristics of Complex Hydrides Lamont Henderson, Sesha Srinivasan, Prakash Sharma The aging effects on the hydrogen storage characteristics and chemical formulations for the complex hydrides are discussed in this presentation. The aging effects due to atmospheric events such as oxygen and moisture coverage and self-decomposition are currently under investigation. The candidate material chosen for this study is Lithium/Magnesium based complex hydride LiBH$_{\mathrm{4}}$/LiNH$_{\mathrm{2}}$/MgH$_{\mathrm{2}}$. These materials were prepared using high energy ball milling under Ar/H$_{\mathrm{2\thinspace }}$atmosphere with different milling durations. The chemical structural and microstructural characteristics of the synthesized materials were studied using FTIR, XRD, BET and SEM analytical tools. Hydrogen storage properties such as hydrogen sorption kinetics, cycle life and pressure-composition isotherm (PCI) was examined via high pressure, high temperature Sievert's type apparatus. This current study will shed light to compare and contrast the above mentioned characteristics for the aged samples practically at the same experimental conditions. Furthermore, we will investigate the relation between the aging effects with respect to the crystallite sizes of the candidate compounds and nano-dopant elements. [Preview Abstract] |
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KA.00029: Inhibition of Collagen Gel Contraction by Fibroblasts using Carbon Nanotubes Elizabeth Wailes, Nicole Levi-Polyachenko Fibroblast cells maintain the extracellular matrix structure that gives mechanical support and instruction to many other cell types throughout the body. When this matrix is severely injured the fibroblasts can over-contract and aggravate the injury instead of healing it properly. We hypothesized that we could restore normal function by doping a collagen gel model of skin with carbon nanotubes, since both collagen and the CNTs are long, thin fibers. Spherical carbon black nanoparticles were used as a control group in addition to MWNT and SWNT to asses whether fibrous particles were responsible for the effect. Nanoparticles were tested at 0.01{\%}, 0.1{\%} and 1{\%} w/v. We found that both MWNT and SWNT were able to significantly inhibit contraction while also increasing cell proliferation by crossing the percolation threshold of CNT concentration in the gel and forming a network. Echoing the literature, this proved to be an aspect ratio dependent effect as both of the nanotube types exhibited this effect but the spherical nanoparticles did not differ from the control at any of the concentrations tested. This decrease in fibroblast contracture coupled with increased proliferation instead of cytotoxic effects from the carbon particles suggests a novel pathway for treating wounds. [Preview Abstract] |
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KA.00030: Ultrafast relaxation dynamics of hot carriers and phonons in graphene-diamond interface: a study towards Carbon sp2 on sp3 technology Zeynab Jarrahi, Justin Gregory, Halina Krzyzanowska, Stephanie Gilbert Corder, Joy Garnette, Jimmy Davidson, Norman Tolk The attraction of graphene in the device arena stems from graphene's high electron mobility and the ability to integrate it on almost any substrate [1]. It has been shown that diamond might be the ultimate substrate of choice for graphene FET and interconnects where the increased performance of Gr/diamond FET has been attributed to the superiority of diamond as a heat sink [2]. This process is ultimately dependent on hot carrier and phonon relaxation dynamics in the Gr /diamond interface which remains unknown to this date. Using ultrafast pump probe spectroscopy, we will contrast the population dynamics of photoexcited carriers and optical and acoustic phonons in CVD grown single layer graphene transferred onto single crystal (111) and (100) as well as poly crystalline diamond substrates. The transient differential reflection spectra will reveal the time scales associated with the cooling cascade of non equilibrium photo generated species. Understanding how relaxation dynamics of graphene is altered by coupling to different diamond interfaces and the effect of diamond on the scattering mechanisms involved, will pave the way towards realization of higher performance carbon sp2/sp3 technology. \\[4pt] [1] Novoselov et al. Nature 2005, 438, 197-- 200\\[0pt] [2] Yu et al. Nano Letters 2012 12 (3), 1603-1608 [Preview Abstract] |
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KA.00031: Parallel Quantum Magnetism Analysis Scott Garland, Larry Engelhardt We present a study of the quantum magnetism simulations within ALPS (Algorithms and Libraries for Physics Simulations) using Francis Marion University's new Patriot Cluster. Supercomputing has become an essential tool for studying a wide variety of phenomena. By pairing ALPS and Python on a parallel machine, many parameter sets for quantum magnetism simulations can be tested simultaneously, allowing a variety results to be obtained rapidly. This project is supported by the NSF EPSCoR RII Track 1 cooperative agreement awarded to the University of South Carolina. [Preview Abstract] |
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KA.00032: Optical and Electrical Characterization of CdTe Functionalized ZnO Nanowires for Energy Anthony Mayo, Haiyang Xu, Yichun Liu, Richard Mu Significant progress has been made recently in understanding optoelectronic properties of ultrasmall quantum dots (a few nanometer in size). Nanostructured photovoltaic devices seems to have clear advantages over the bulk counterparts to address energy problems facing humanity. Nanostructured devices require much less mass and not exclusively limited by materials of choice, and favoring integration for multifunctionality. It is known that we can effectively harvest solar energy by tuning the optical gap and enhancing photon absorption across section through various nanomaterials syntheses. The remaining challenges is to be able to purposely control and manipulate the energy transfer pathways for particular needs. Thus, charge and exciton transports must be carefully evaluated. The knowledge of charge and exciton mobility, coherent and incoherent hopping due to electronic coupling, energy redistribution and partition in real time may be the critical steps. Here, CdTe functionalized ZnO nanowires have been fabricated with Glazing Angle Deposition technique as a model system. A series materials characterization techniques (confocal Raman, optical, photoluminancence and electrical) have been conducted and optimized to provide valuable information about the nanostructure. Results will be present and discussed at the meeting along with the implications. These findings serve as the solid foundation for more sophisticated study that follows. [Preview Abstract] |
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KA.00033: Exciton-Plasmon Coupling in ZnO/MgO Core-Shell Nanowires Claire Marvinney, Daniel Mayo, Ephraim Bililign, Richard Mu, Richard Haglund Zinc oxide (ZnO) has emerged as one of the most promising materials for optoelectronic applications. A wide direct bandgap of 3.37 eV with a large exciton binding energy of 60 meV results in a band-edge exciton that is more thermally stable than the commonly used semiconductor GaN. Room temperature photoluminescence (PL) spectra for ZnO exhibit a sharply defined peak centered at 3.3 eV, and a broad visible peak centered around 2.3 eV. One of the most effective methods for PL enhancement for optoelectronic devices is through the Purcell mechanism via coupling localized surface plasmons to the ZnO luminescent centers. We have demonstrated dramatic band-edge emission enhancement and quenching in core-shell ZnO/MgO NWs coated variously with Ag, Al, and Au nanoparticles. The MgO coating acts as an insulating layer allowing isolation of plasmon-mediated emission due to hot-electron transfer from that due to local field mechanisms. Extremely large band-edge PL enhancement occurs at specific MgO shell thicknesses. This band-edge enhancement is hypothesized to be due to Fabry-Perot cavity resonances in the core-shell NW. Functionalization of the core-shell NWs with the various metal nanoparticles species results in PL enhancements that correspond to the strength of the plasmonic coupling, with Al nanoparticles exhibiting the highest PL enhancement. These results establish the plasmonic core-shell NW structure as a strong platform for optoelectronic applications. [Preview Abstract] |
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KA.00034: Geometric patterning with HIM at CNMS Allison Linn, Adam Rondinone, Edward Kintzel Electron microscopy is one of the most used analytical techniques available for materials science and nanoscience research. Recent technical advances in these areas have exposed the need for enhanced spatial resolution and depth-of-field. The helium-ion-microscope (HIM) is an instrument designed to answer these and other materials needs. The Center for Nanophase Materials Sciences (CNMS) located at Oak Ridge National Laboratory is commissioning the world's first helium-ion microscope tailored specifically for imaging, nanopatterning, and nanofabrication. In the present survey study, our group sought to develop the parameters necessary to pattern a variety of geometric shapes into single-layer graphene on a SiO$_{2}$ substrate utilizing the HIM at the CNMS. The uses for graphene are still being explored, and as such have become important recently for its use in nanoelectronics. Employing the patterning software in the HIM, we used a combination of dose and dwell time to pattern the graphene. Future studies will seek to refine the patterning process for graphene and other technical relevant materials. [Preview Abstract] |
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KA.00035: Comprehensive structural characterization and surface properties of graphene -- \textit{21}$^{st}$\textit{ Century wonder material} Maxwell Dierken, Eli Heintzman, Harry Heyworth, S. Gupta Among the family of carbon-based systems, graphene is one of the youngest members existing in crystalline form alongside diamond, graphite, fullerenes and carbon nanotubes. Moreover, graphene is described as a one-atom thick layer of the layered mineral graphite. Graphene has attracted a great deal of attention since 2004 when it was successfully isolated through scotch-tape method furthered by other preparation methods. Since its inception, a flurry of research activities have initiated around the world attributed to their extraordinary physical (electronic, mechanical, thermal, optical and electrochemical) properties for a gamut of technologies. However, it is indispensable to investigate their structure to establish \textit{microscopic structure- property} relationship. Here we study the structural and surface properties of graphene prepared \textit{via} two approaches namely, exfoliation and controlled scotch-tape methods, revealing mono-, bi-, tri- and multi-layers. A range of analytical characterization techniques include optical and atomic force microscopy, transmission electron microscopy combined with electron diffraction and resonance Raman spectroscopy with mapping, have been employed determining the number of layers, surface roughness / uniformity / homogeneity, nanoscale structure through diffraction, thus assessing the quality of graphene and provides a comprehensive understanding of the structure for a range of electronic and electrochemical applications. [Preview Abstract] |
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KA.00036: Generalized Three-Body Gravitational Systems Nicholas Lucas The three-body problem deals with the orbits of three bodies caused by the gravitational effects on one another. This problem is examined for various special initial conditions to minimize parameters allowing a classification scheme of the orbits complexity to be created. A phase space is used to visualize the complexity of orbits with varying initial conditions. Investigation of the phase space shows distinct patterns for different types of orbits and complexity levels in the systems. Further generalization of the gravitational force law to an arbitrary power dependency of the distance between respective bodies produces results of great interest. It is possible in other power law's to obtain stable orbits of considerable simplicity and complexity depending on initial conditions much like that for the standard gravitational force law. [Preview Abstract] |
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KA.00037: Evolving the Wave Equation on Hyperboloidal Slices Samuel Cupp, Peter Diener, Frank L\"offler The Extreme Mass Ratio Inspiral problem (EMRI), a system of interest for numerical relativity and important model for gravitational wave research, consists of a compact object spiraling into a supermassive black hole. In such systems the inspiral evolution is partly determined by waves propagating out from the compact object, back scattering off the space-time curvature and returning to interact with the compact object at a later time. Thus, in principle, it is necessary to have the computational domain extend all the way to infinity. Here we use compactification and hyperboloidal slicing to achieve this for the scalar wave equation (used as a simpler test problem than the full gravitational case). Our derivation and implementation for a flat space-time successfully propagates waves to infinity and resolves both a pulse and a continuous boundary wave for this space-time. [Preview Abstract] |
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KA.00038: Electrical Bulk Resistivity Measurement of CdZnTe-based Radiation Detectors Sam Uba, Madhu Goundla, Charles Payton, Stephen Babalola, Claudiu Muntele, Trent Montgomery CdZnTe crystal works as ideal radiation detector device because of its attractive properties, especially its high band gap energy that enables it to operate at room temperature. In this research we studied the surface leakage current of CdZnTe-based detectors. We obtained current-voltage measurements of three CZT detectors and analyzed the surface leakage current as a function of surface defects and processing. The bulk resistivity of the CZT detectors were calculated from the current voltage measurements, and for each surface preparation technique we determine the surface leakage. We then compared the results and the leakage currents were correlated with surface processing during the device fabrication of the CZT crystals. Acknowledgments: Universities-Laboratories Consortium for radioisotope detection and analysis (UL-CORDA), funded by DOE NNSA under the Minority Serving Institutions Partnership Program (MSIPP). This work is also supported by AAMU HBCU-UP project grant {\#}0928 904 [Preview Abstract] |
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KA.00039: Initial Discoveries from the GBNCC Pulsar Survey Jason Boyles, Kevin Stovall, Ryan Lynch, Scott Ransom The GBNCC pulsar survey is a large scale survey to look for radio pulsars at 350-MHz with the Robert C. Byrd Green Bank Telescope with the primary goal of finding new millisecond pulsar for use in pulsar timing array for gravitational wave detection. The data collection started in 2009 and is on going. We have collected approximately 2000 hours of data, which 75\% of the data has been searched for pulsars. We currently have discovered 68 new pulsars including nine millisecond pulsar and seven rotating radio transients. Three of the millisecond pulsars have been added to the regular programs for detection of gravitational waves. We present an initial look at the first discoveries from this survey. [Preview Abstract] |
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KA.00040: The Generalized Mattig Relation for a Gauss Bonnet Gravity Model Keith Andrew, Nick Zolman In this work we study the form of the Mattig equation applied in a cosmological setting for spacetime metric gravity models described by the Gauss-Bonnet action. We start with expressing the Mattig relation for cosmological magnitudes in terms of standard metric functions and redshift values. Then we present the Gauss-Bonnet field equations and the associated limits for special solutions in an arbitrary number of dimensions. These solutions are then used to rewrite the Mattig relation with correction terms from the Gauss-Bonnet contributions. We compare these terms to the error bars associated with the observed late time accelerated expansion caused by the cosmological dark energy. We find that the Gauss-Bonnet couplings must be very small to match the observational data. [Preview Abstract] |
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KA.00041: Numerical Analysis of the Z Dependence of Cosmological Void Probability Functions Keith Andrew, David Barnaby, Brett Bolen, James Gary, Lisa Taylor We use a numerical N-body cosmological simulation code, Gadget II, and survey data from CfA, DEEP2, 2dF and SDSS to investigate the z dependence of the distribution of voids characterized by the Reduced Void Probability Function, RVPF. We numerically simulate the evolution of the universe on a Beowulf Cluster in a LCDM model starting from a redshift of z$=$50 to the current epoch at z$=$0 in order to generate RVPFs for N\textgreater 10$^{6}$. GADGET-2 is an N-body/smoothed particle hydrodynamics, SPH, code that we ran in MPI parallelizable mode on a HPC Beowulf cluster. The clustering probabilities are compared to a statistical model utilizing a hypergeometric partition function representation to capture both the Thermodynamic and Negative Binomial probabilities. We model the z dependence of the void density profile to extract a nonlinear exponent equation covering all data sets indicting the time evolution of the cosmic void structure. We find the value of the generalized partition function that gives the best fit to the model and the available observational data. [Preview Abstract] |
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KA.00042: The Power of Thermonuclear Supernovae at Late Epochs Ginger Bryngelson, Mark Leising, Peter Milne Type Ia supernovae (SNe Ia) shape our understanding of the expansion of the universe in their use as distance indicators. Thought to be the runaway thermonuclear explosion of a white dwarf star in a binary system, SNe Ia are bright enough to be seen in far-way galaxies. Their brightness fades slowly over hundreds of days, powered by radioactive isotopes synthesized in the explosion. At some point after 200 days, the continually expanding ejecta is diffuse enough to allow gamma-rays to escape, and soon the brightness of the SN is only powered by positrons trapped by the SN's magnetic field. Only a handful of SNe Ia have been observed during epochs later than 200 days after explosion in both visible and near-infrared light. We discuss our observations of multiple SNe Ia which exploded in nearby galaxies. These were bright enough to be observed out to late epochs (about 525 days post peak). Their brightness was monitored over time in visible light (B,V,R,I bands) and near-infrared (J,H,K) bands, and light curves were constructed. We convert these observations to luminosity and compare them to a simple positron deposition model to estimate the feasibility of positron escape. [Preview Abstract] |
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KA.00043: Chemical Abundances of Compact Planetary Nebulae in the Galactic Disk Ting-Hui Lee, Richard Shaw, Letizia Stanghellini We present preliminary results from an optical spectroscopic survey of compact planetary nebulae (PNe) in the Galactic disk. This is an ongoing optical+infrared spectral survey of 150 compact PNe to build a complete database of PN chemical abundances in the Galactic disk. The optical spectra will be combined with {\em Spitzer} spectra of IR collisional lines to improve some abundance constraints. Our targets are mostly young PNe, which are well suited for studying the impact of metallicity and dust on PN morphology. Our main objectives are: (1) to constrain stellar evolution models and (2) to quantify the contribution of low- to intermediate-mass stars to chemical enrichment. We will also compare these findings to our optical+IR Magellanic Cloud PN abundances to better understand the influence of environment metallicity on stellar chemical yields. [Preview Abstract] |
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KA.00044: Analysis of Lyapunov Structure for a Nonlinear Field Representation for Blazar Optical Microvaraibility Keith Andrew, Aaron Brzowski, Andrew Brown, Cameron Hubbard, Michael Carini Utilizing observational data available from Bell Astrophysical Observatory and the Kitt Peak Robotically Controlled Telescope on the micro-variability of Blazars in the optical regime we analyze the general intensity equations for the Blazar jet. The equations model extreme states of matter for a slowly decelerating conical jet geometry that can include relativistic effects coupled to magnetically dominated accelerating parabolic base transitioning to the slow acceleration regime. We look at the inverse Compton emission from the synchrotron radiation and examine terms that could account for accretion disk, CMB scattering, dusty torus interactions and turbulence effects. The variations are characterized by the Hurst exponent and maximum correlation dimension to determine how close the microvariability is to being Brownian. The resulting equations have regimes that are strongly nonlinear that have unstable equilibria near regions that have a positive Lyapunov exponent. These regimes are being explored for parameter values that might lead to chaotic dynamics that could alter the variability of light received by the blazer on several time scales. [Preview Abstract] |
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KA.00045: Analyzing Images of Supernova 2010ih Dorothy Dickson-Vandervelde, Ginger Bryngelson SN 2010ih is a type Ia supernova, which is thought to come from a binary star system in which at least one of the stars is a white dwarf. The white dwarf gains mass until it reaches the Chandrasekhar limit, where the pressure and temperature set off a runaway thermonuclear explosion. We plan to analyze the light curve of the supernova to characterize the late-time behavior of the supernova and also to figure out the distribution of the different radioactive isotopes. I reduced and combined images of the Supernova 2010ih and then analyzed it for brightness and began the formation of a light curve, which is a graph of magnitude verses time. SN 2010ih was observed on January 10 and 11, 2011, about five months after it was discovered, at Kitt Peak National Observatory with the 4m Mayall Telescope in the visible light bands B, V, R, and I. I used the software Image Reduction and Analysis Facility (IRAF) to analyze and reduce the images. I removed bad pixels and crosstalk, subtracted the darks and the zeros, divided out the flats, fit the image to a world coordinate system, and then combined the images into a final image, for each filter; B, V, R, and I. After achieving the four final images, I found the magnitude for the supernova and thirty field stars. [Preview Abstract] |
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KA.00046: Dark Gas in the Interstellar Medium Steven Gibson, Mary Spraggs, James Hughes, Bon-Chul Koo, Geumsook Park Most of the interstellar material in disk galaxies, including our own, is too warm and tenuous to form new stars. Yet somehow, clouds cold and dense enough to collapse under their own gravity do occasionally coalesce. This mysterious process is enabled by the gas changing from predominantly free atoms to molecules that enhance radiative cooling. Molecular association is not directly observable, and the gas itself is often ``dark'' to standard probes like spectral line emission from neutral atomic hydrogen or carbon monoxide. But under the right circumstances, this dark gas can be revealed, e.g., as opaque hydrogen emission or absorption, or as infrared continuum radiation from dust grains mixed with hidden molecular hydrogen. We have mapped tracers of such gas over large areas of the Galactic disk at high resolution. We find dark gas clearly revealed in many areas. We present maps of sample features and discuss their properties and relation to Galactic structure. [Preview Abstract] |
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KA.00047: Autonomous Astronomical Observing As A Way To Involve Students In Research Stacy Hancock, Richard Gelderman, Ken Cook, Derek Stice, Patrick Miller, Tomas Vorobjov, Michael Carini, David Laney, Charles McGruder, Louis-Gregory Strolger The 1.3-meter diameter Robotically Controlled Telescope (RCT) on Kitt Peak, Arizona is a robotically operated observatory available to students for use as classroom laboratory equipment. Using data from this research class instrument, students learn science by doing scientific investigations, via world-wide projects such as the Global Hands-On Universe (GHOU) and International Astronomical Search Collaboration (IASC). Through these research-based learning curricula, students learn science as they carry out their own investigations with the chance to discover something unexpected. With a greater degree of autonomy in deciding how they carry out their investigations, and are motivated by being allowed to take responsibility for their own learning. Built into research-based learning is a premium on teamwork as students work with their peers and professional astronomers. Unlike the case of textbook lessons, students have to make their own decisions and thus develop critical thinking skills. In this presentation describe the research results of students working on IASC and GHOU research projects. [Preview Abstract] |
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KA.00048: RCT and Kepler observations of the highly variable Seyfert galaxy II ZW 229.015 Josh Williams, Michael Carini ZW 229$+$015 is the brightest AGN in the field of view of NASA's Kepler spacecraft. Its brightness was continuously monitored by the Kepler spacecraft until Kepler science operations were suspended due to a reaction wheel failure. Contemporaneous ground based observations of the brightness of ZW 229.015 were obtained with WKU's Robotically Controlled Telescope to serve as ``ground truth'' observations of the observed variations in the Kepler light curve. In this poster, we present the results of our ground based monitoring of ZW 229.015 with the RCT along with the Kepler light curve and time series analysis of the Kepler light curve. [Preview Abstract] |
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KA.00049: Calculating Redshifts for Planck Discovered Galaxy Clusters Hillary Head, Shantanu Desai One of the outcomes from the Planck mission was the discovery of new galaxy cluster candidates using the Sunyaev-Zel'dovich effect. Working with collaborators at USM, my project involved confirming which detections were clusters and which were false positives, and then finding the redshifts of the newly discovered clusters using Pan-STARRS optical data photometrically calibrated using SLR techniques on SExtractor cataloged images. The redshifts were determined using the greatest likelihood from a red-sequencing technique. The results from this method were the finding of redshifts for seven new clusters. Future work will include creating a bootstrapping method from redshifts gained on known clusters to their correct values and applying this to the new clusters, as well as tweaking the red-sequencing code to be better at determining redshifts for these clusters. [Preview Abstract] |
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KA.00050: Time Series Analysis of the Blazar OJ 287 Ellen Gamel, Wes Ryle, Michael Carini Blazars are a subset of active galactic nuclei (AGN) where the light is viewed along the jet of radiation produced by the central supermassive black hole. These very luminous objects vary in brightness and are associated with the cores of distant galaxies. The blazar, OJ 287, has been monitored and its brightness tracked over time. From these light curves the relationship between the characteristic ``break frequency'' and black hole mass can be determined through the use of power density spectra. In order to obtain a well-sampled light curve, this blazar was observed at a wide range of timescales. Long time scales were obtained using archived light curves from published literature. Medium time scales were obtained through a combination of data provided by Western Kentucky University and data collected at The Bank of Kentucky Observatory. Short time scales were achieved via a single night of observation at the 72'' Perkins Telescope at Lowell Observatory in Flagstaff, AZ. Using time series analysis, we present a revised mass estimate for the super massive black hole of OJ 287. This object is of particular interest because it may harbor a binary black hole at its center. [Preview Abstract] |
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KA.00051: Bell, Crimea and RCT -- Three Research Grade Optical Telescopes assessable to Western Kentucky University Astronomers Charles McGruder, Krill Antoniuk, Michael Carini, Scott Engle, Richard Gelderman, Edward Guinan, Llindsay Kriz, David Laney, D Shakhovskoy, Louis Strolger, Richard Treffers, Donald Walter, Joshua Williams We present the accuracy and precision both astrometric and photometric achieved with each telescope. The telescopes are longitudinally distributed. We discuss the advantages of observing fields sequentially by these three telescopes. [Preview Abstract] |
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KA.00052: Structure of Tin-Fluorophosphate Glasses for Solar Energy Applications Travis Tanner, Justin Oelgoetz, Roman Golovchak, Carrie Brennan, Andriy Kovalskyy One way to improve the effective efficiency of photovoltaics is to make more of the solar spectrum available for energy conversion. On way of accomplishing this is to up or down convert photons outside the most useful energy range into the more useful range. To this end, investigation on both undoped and Er- doped tin-fluorophosphate glasses (50SnF$_{2}$-20SnO-30P$_{2}$O$_{5})$ has begun. Raman Spectroscopy and high-resolution X-ray Photoelectron Spectroscopy (XPS) methods were utilized to characterize the undoped and doped samples. Analysis of Raman spectra at different excitation energies (488 nm, 532 nm, 785 nm and 1064 nm) did not reveal major effects associated with doping but noticeable changes between the structure of bulk and surface layers of the glass were found. A model of the glass structure based on these results will be presented. [Preview Abstract] |
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KA.00053: Laser Photodetachment Spectroscopy of the $S_{2}^{-}$ Ion Jessica Barrick, John Yukich We have conducted low-resolution photodetachment spectroscopy of the $S_{2}^{-}$ ion over a broad range of photon energies. The ions are created in an ion trap by a two-step dissociative attachment process. The detachment is achieved with a tunable ring-cavity titanium:sapphire laser. Evaporative cooling is used to remove the most energetic ions. The altered photodetachment spectroscopy is then compared to that of the non-cooled ions as a method of identifying detachment thresholds. Our results exhibit structure that may be due to vibrational energy levels. Future experiments will focus on high-resolution detachment spectroscopy of these and other ions. [Preview Abstract] |
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KA.00054: BSA protein adsorption on bioglass and bioceramic surfaces Joe Harms, Roman Golovchak, Himanshu Jain Advancements in medicine have yielded biodegradable scaffolds to restore diseased or damaged tissues. Scaffolds made of bioactive glasses, specifically the 45S5 composition, are designed to fill and restore bone defects. Most of the studies in the field of 45S5 bioactive glasses have tried to model the interaction between the living tissue and the glass using Simulated Body Fluid (SBF) solution. SBF contains a concentration of ions similar to human plasma to predict in vivo bone formation. However, cells do not attach to the surface of bioglass, but through a layer of mediate adsorbed proteins. The adsorbed protein layer modifies interactions between cells and biomaterial. Not only is the composition of the adsorbed protein layer important, so is the conformational state of each protein. In present studies we report the first results on X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy studies of bovine serum albumin (BSA) attachment to various surfaces of 45S5 bioglass and bioceramics. The XPS shows the amount of BSA attached to the surface depends strongly on the concentration of Ca and P. Thus Ca$^{\mathrm{2+}}$ and PO$_{\mathrm{4}}^{\mathrm{3-}}$ could be identified as main protein binding sites. Conformations of BSA proteins attached at different temperatures are studied by micro Raman spectroscopy. [Preview Abstract] |
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KA.00055: Simulation Analysis of the Effects of Partial Charge Modifications on the Hydrophobicity of Lignin Christopher Carmona, Jeremy C. Smith, Paul Langn, Loukas Petridis Lignins are hydrophobic, branched polymers that provide protection against chemical and biological degradation as well as regulate water conduction in plant cell walls. By associating with hemicellulose, lignins form a barrier against effective hydrolysis of plant biomass for cellulosic ethanol production. The effects that the hydrophobicity of lignin has on its association with hemicellulose are not currently well understood. Here, modifications are implemented on three models of lignin based on hydroxycinnamyl aldehydes which are precursors to monolignols along their biosynthetic pathways. Hydroxycinnamyl aldehydes can be genetically engineered into lignin polymers and vary in composition of hydrophobic and hydrophilic functional groups. Each model of lignin is equilibrated beside hemicellulose and then simulated together in an ionized aqueous solution at room temperature. These simulations of partial charge modified lignin, resulting from additional functional groups, provides insight into the overall role that the hydrophobicity of lignin has on its interactions with hemicellulose. Moreover, these insights reveal the effects that inclusion of hydroxycinnamyl aldehydes into the lignin polymer may have on the efficiency of biomass pretreatment for cellulosic ethanol production. [Preview Abstract] |
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KA.00056: Mechanical properties of human cancer cells Xinyi Guo, Keith Bonin, Martin Guthold Here we plan to report on the elastic Young's modulus E measurements of individual cells from a cell line that has normal, immortal, and tumorigenic cells. The Young's modulus is measured using an atomic force microscope (AFM) with a spherical tip of 5.3 $\mu$m in diameter. Results demonstrate that a cell's environment influences its stiffness, and that cells become softer as they get to the most advanced transformed stage. The Young's modulus measurements were made on cytoplasm and on nuclear regions (in all 3 types of cells) to how the modulus depended on cell region. We also measured cells in three different environments: isolated, at the periphery of a colony, and in the middle of a colony. We will report results on all three cells in the three different environments and for both cell regions. [Preview Abstract] |
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KA.00057: Surface Preparation for Improved Molybdenum Disulfide Nanoelectronics Sirak M. Mekonen, Hugh Churchill, Pablo Jarillo-Herrero Recent advances in nanoscale materials characterization and device fabrication have opened up new opportunities for two-dimensional layers of Transitional metal dichalcogenides (TMDs) in nanoelectronics and optoelectronics. TMDs are a family of materials including the layered semiconductor molybdenum disulfide (MoS$_{2})$. TMDs, such as MoS$_{2}$, have sizable bandgaps that change from indirect to direct in single layers, allowing applications such as transistors. We proposed AFM contact mode operation to clean the MoS$_{2}$ surface for improved electronic transport measurements. The project involved low-temperature measurements of electrical properties in exfoliated monolayer devices. Monolayer MoS$_{2}$ based devices were fabricated from bulk MoS$_{2}$ by micromechanical cleavage using adhesive tape, which was then applied on highly doped silicon substrates. Monolayer flakes were optically identified by light interference. Device surface topographies were determined via atomic force microscopy (AFM). Electrical contacts (1nm Ti and 50nm Au) were patterned using e-beam lithography. AFM contact mode cleaning was performed to reduce contact resistance and increase carrier mobility. Electrical transport measurements are ongoing to quantify the improvement in the cleaned devices. [Preview Abstract] |
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KA.00058: The Simulation of Slow Pulses in PPC Detectors Jordan Baldwin, David Radford, Mary Kidd The Majorana Demonstrator project, an international collaboration among 20 universities, is attempting to determine the mass of the neutrino by using an array of P-type point contact (PPC) germanium detectors to identify neutrinoless double beta decay. This point contact configuration allows us to identify neutrinoless double-beta decay events based on pulse-shape analysis. However, the dead layer around the perimeter of the PPC germanium detector significantly slows the collection of charge deposited there and distorts the shape of the resultant pulse. We have been developing simulations to further understand the physical mechanism that produces the slow pulses, namely diffusion and recombination in the dead layer. The results from these simulations are compared to experimental data obtained from a PPC detector. [Preview Abstract] |
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KA.00059: The Study of Defects in Cadmium Zinc Telluride Crystals Charles Payton, Stephen Babalola, Trent Montgomery, Claudio Muntele Cadmium Zinc Telluride (CZT) has desirable properties making it a good candidate for radiation detection. Despite the positive properties of CZT its theoretical performance is sub-optimal because of material defects. The scope of this work focuses on understanding the agglomeration of Tellurium atoms in the lattice, dislocations, and grain and twin boundaries on the surface. Nakagawa and Saucedo solutions were used to etch the surface of CdZnTe crystals to reveal etch pits. Infrared (IR) imaging and Scanning Electron Microscopy (SEM) were used to study the defects within the crystals. After etching the surface of the CZT crystal, Etch Pit Density (EPD) estimation of the population of Tellurium inclusions on the surfaces of the crystals were performed. Infrared imaging revealed Tellurium inclusions as distinct features around dislocations and boundaries. SEM was used to study the features of observed defects. This work shows defects that are responsible for sub-optimal performance of CZT as a radiation detector. Ongoing research is aimed at correlating the observed and characterized defects with detector performance. [Preview Abstract] |
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KA.00060: Forward Time of Flight Reconstruction Software for CLAS 12 Alexander Colvill, Gerard Gilfoyle Jefferson Laboratory is upgrading its facilities to double the electron beam energy and, among other projects, build a new detector CLAS12 in Hall B. The Forward Time-of-Flight system (FTOF) in CLAS12 is an essential component for particle identification. It is constructed of scintillator strips combined to form large triangular or rectangular panels. Software has been developed to reconstruct signals from the FTOF that enhances existing software written for the previous detector in Hall B. This new software, written in Java, runs in the CLAS 12 Reconstruction and Analysis Framework as a self-contained service. The optimal configuration for this service was determined using simulations of CLAS12 and deep inelastic scattering of 11-GeV electrons from a hydrogen target. It was determined how best to combine signals on adjacent scintillation paddles from a single particle striking an FTOF panel. The key conclusions were that each panel should be treated separately, and that, as it is possible for a single particle to leave signals in more than two adjacent paddles, signals from those adjacent paddles should be combined. With these alterations, efficiency increased by up to 10\% compared with existing methods. [Preview Abstract] |
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KA.00061: Analysis of Systematic Sources of False Parity Violating Proton Asymmetry in the 3He(n,p)T Reaction Jonathan Serpico, Ivan Novikov The 3He(n,p)T experiment in one of four experiments needed to provide information on hadronic weak interaction. The experiment is an ongoing effort at the SNS ORNL. The objective of the experiment is to measure parity violating (PV) spin-dependent proton asymmetry. We have conducted an analysis of systematic sources of PV asymmetry due to neutron energy variations in the beam. The neutron energy dependence of various observables was calculated in the framework of nuclear resonance reaction theory. [Preview Abstract] |
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KA.00062: The Study of Neutrino Properties from Dark Matter Annihilations in the Sun Ranjani Sarma NOvA (NuMI Off-Axis ve Appearance) is an experiment studying a neutrino beam sent from Fermilab to northern Minnesota. The main goal of NOvA is to observe neutrino oscillations. NOvA can also be used for many other different experiments. We use upward-going muons to investigate the possibility of dark matter in the center of Sun. Weakly Interacting Massive Particles (WIMPs) are currently the main candidates for dark matter. We have been studying neutrino propagations from annihilations of WIMPS at the core of the Sun. WIMPSIM is a program that simulates WIMP annihilations in the Sun and then propagates the resulting neutrinos to the surface of the Earth. The data from WIMPSIM helps us study angular acceptance of neutrino yields. This will give us a better understanding of upward-going muons so we can more easily recreate them in a toy Monte Carlo. [Preview Abstract] |
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KA.00063: Interpolating Quantizaton from Instant to Light-front using Clifford algebra Murat An, Chueng Ji We studied applications of Clifford algebra $Cl_{1,3} $ in interpolating quantization which is between light-front form and instant form quantization by an interpolation angle. We show that Poincare algebra is a part of Clifford algebra and spinors can be expressed as projections of Clifford numbers. This study shows how Clifford algebra is eligible to not only for standard basis of quantum but also any other basis and how ease our step with avoiding matrix and commutation relations usage. [Preview Abstract] |
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KA.00064: Geometric Fixed Hyperplane Rotations of SU(1,1) and Sp(2,R) Khaldi Khalida, Keith Andrew, Eric Steinfelds, Ivan Novikov We develop the tools needed to provide a geometric demonstration of the isomorphisms exhibited between the groups SU(1,1) and Sp(2,R) by using elements of SU(2,C). Using the matrix representation in terms of 2x2 complex matrices with unit determinant the action of each group can be seen as transformations with respect to the fixed hyperplanes for the coordinates x$_{1}$, x$_{2}$ and x$_{3}$. The construction is based upon the determinant constraint expressed in terms of the spacetime interval for Hermetian generators that are from SU(2,C). This work follows the strong connection used in twistor theory in a four dimensional complexified spacetime of signature (2, 2) based upon the isomorphism between Spin(4,2) and SU(2,2). [Preview Abstract] |
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KA.00065: Open Science Grid (OSG) Tier3 Grid Supercomputer at Bellarmine University Bryan Fagan, Tyler Martinez, Akhtar Mahmood Today's cutting-edge scientific projects are larger and more complex. Grid computing provides the resources that allow researchers to share knowledge, data, and computer processing power across boundaries. At Bellarmine University, we have built a state-of-the-art Tier3 Supercomputer that is linked to the Open Science Grid (OSG) cyberinfrastructure with funding from the NSF. The 51-node Supercomputer is equipped with 408 cores, 1300GB of RAM and 375TB of disk storage space. It is currently the only OSG grid site in the state of Kentucky. It is also the first OSG grid site to be located at an undergraduate institution. Condor provides a job queuing mechanism, scheduling policy, priority scheme, resource monitoring, and resource management. The Tier3 grid site is also part of the Worldwide LHC Computing Grid (WLCG). We have set up and implemented various web portals for monitoring the Tier3 supercomputer's performance (which is running Scientific Linux 5.4), using PCM (Platform Cluster Manager), Cacti (a web-based graphing tool) and Nagios (a network monitoring software application). The Supercomputer has already processed over 150,000 OSG grid jobs submitted from the D0 and the ATLAS experiments and has clocked in over 1,300,000 CPU hours since June 1, 2011. [Preview Abstract] |
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KA.00066: Construction of a Quantum Optics Laboratory for Detecting Single Photon Coincidence Counts Jason Harrington, Ryan Widejko, Preston Alexander, R. Sethfield Smith The purpose of this research was to construct an experimental apparatus for performing undergraduate level quantum optics experiments. Specifically, our goal was to set up the equipment required for detecting coincidence counts of photons emitted from a 405-nm diode laser (pump beam). The process of spontaneous parametric down conversion was utilized to convert the 405nm pump beam into two 810nm signal and idler beams. Through the implementation of an Altera DE2 field programmable gate array, along with four single photon counting modules, real time viewing of the experimental data was performed. This experimental setup provides undergraduate students with the opportunity to perform a variety of interesting experiments, many of which are designed around the production of pairs of photons that are used to test predictions made by Quantum Theory. Some of these experiments include the Grangier experiment, single photon interference, the Quantum eraser, tests of local realism, and tests of entangled and mixed states. [Preview Abstract] |
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KA.00067: UAHuntsville and NASAMSFC Heliophysics NSF REU SITE: Year Two Achievements and Challenges Samaiyah Farid, Jacob Heerikhuisen, Amy Winebarger In 2012, scientists at the University of Alabama in Hunstville and NASA Marshall Space Flight Center were awarded a 3 year National Science Foundation grant to become a Research Experience for Undergraduates (REU) site. For the past two years, we have hosted a diverse group of 10 undergraduate students to engage in cutting edge heliophysics research. The primary objectives of this REU are to increase minority participation in science, technology and mathematics (STEM) fields in general, and heliophysics in particular, and decrease the STEM attrition rate in first and second year students. This REU is unique because of our focus on recruiting talented students that may not otherwise participate in a research program. In addition to the usual criteria a consideration of ``need'' was also given to those students who were sophomores, students with little or no previous research experience, those from small or nonPhD granting institutions, students with GPA less than 3.0, minorities and women. In our second year, we have increased minority participation to 50 percent, from 20 percent, admitted 2 first-year REU students into graduate school at UAH in heliophysics related fields, two REU students are co-authors on research published in scientific journals (one in Science magazine), and all students from both years submitted poster presentations to a national scientific conference. In this poster we discuss our program and outline challenges and goals for the upcoming year. [Preview Abstract] |
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KA.00068: Addressing Quantitative, Conceptual and Writing Goals in an Introductory Laboratory Scott Bonham, Doug Harper There can be a number of different goals in introductory physics laboratories, such as measurement and data, conceptual understanding, and scientific communication. When the department revised the first semester calculus-based physics lab, a task force developed learning objectives, which emphasized measurement, data and analysis, but also gave importance to conceptual understanding and scientific communication. This poster will describe strategies used to address the different objectives at the same time. Many labs have both a qualitative (conceptual) component as well as a quantitative component, on-line pre-lab questions are used to help students prepare for lab, including identifying main concepts and reading technical material, and scaffolding approaches are used to help students learn the software and develop their technical writing skills. Positive results in the evaluation will also be shown. [Preview Abstract] |
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KA.00069: Evaluating Laboratory Report Writing Skills Kolton Jones, Scott Bonham Western Kentucky University Physics and Astronomy Department's University Physics 1 Labs utilize several strategies to teach good writing skills. This includes two examples lab reports, one good and one poor, that students evaluated according to the grading rubric which is used to evaluate student's work. Students initially turned in partial reports, responsible for one section addition section each week, which were evaluated and returned to the student with feedback. Copies of student work were kept and coded for quality of many different aspects of the report. Different patterns of student progression over the semester were observed. For example, the quality of the experimental description showed improvement with time while the data and analysis section fluctuated with no over-all trend. More results and implications for instruction will be presented. [Preview Abstract] |
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KA.00070: Student Entrepreneurs as Active Leaders David Norwood, Jean Fotie, Debra Dolliver SEAL is a program of Southeastern Louisiana University Department of Chemistry and Physics, initially funded by the Louisiana Board of Regents and now self-sufficient, to teach important business and technology entrepreneurship skills to Southeastern students. In the process, the students answer scientific and technical questions for Louisiana businesses, putting the equipment and expertise of Southeastern faculty and students at the service of Louisiana businesses, large and small. [Preview Abstract] |
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KA.00071: Multi-Speed Thought Experiment Florentin Smarandache We consider n \underline {\textgreater } 2 identical rockets: $R_{1}, R_{2}$\textit{, \textellipsis , R}$_{n}$. Each of them moving at constant different velocities respectively v$_{\mathrm{1}}$, v$_{\mathrm{2}}$, \textellipsis , v$_{\mathrm{n\thinspace }}$on parallel directions in the same sense. In each rocket there is a light clock, the observer on earth also has a light clock. All $n +$\textit{ 1} light clocks are identical and synchronized. The proper time $\Delta t'$ in each rocket is the same. Suppose that the $n$ speeds of the rockets verify respectively the inequalities: \textit{0 \textless v}$_{1}$\textit{ \textless v}$_{2}$\textit{ \textless \textellipsis \textless v}$_{n-1}$\textit{ \textless v}$_{n}$\textit{ \textless c.} The observer on rocket R$_{\mathrm{1}}$ measures the non-proper time interval of the event in $R_{j}$ as: $\Delta t_{1,j\thinspace }= \Delta $\textit{t'\textbullet D(v}$_{j}-v_{1}),_{\thinspace }$ therefore the time dilation factor is $D(v_{j}-v_{1}),_{\thinspace }$where j$\in $\textbraceleft 2, 3, \textellipsis , n\textbraceright . Thus the time dilation factor is respectively: $D(v_{2}-v_{1}), D(v_{3}-v_{1}$\textit{),\textellipsis , D(v}$_{n}-v_{1}), $ which is again a multiple contradiction. Because all $n$ rockets travel in the same time, we have a dilemma: which one of the above \textit{n-1} time dilation factors to consider for calculating the non-proper time as measured by the observer in rocket $R_{1}$? Similar dilemma if instead of the observer in rocket R$_{\mathrm{1}}$ we take the observer in rocket $R_{k},$ for \textit{2 }$\le k \le $\textit{ n-2.} Also a same multiple dilemma occurs if we take into consideration each rocket's length, which gets contracted in multiple different ways simultaneously! [Preview Abstract] |
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KA.00072: Stratospheric Radiation Measurements via a High Altitude Balloon Dylan Wood, Ryan Adams, Bryan Gaither, B. Alexander King, Spencer Buckner, Justin Oelgoetz High altitude balloons serve as a relatively inexpensive and simple method to study a unique environment with extremely low temperatures and pressures, far above most of the atmosphere, and may be used to carry a wide variety of experiments. Austin Peay State University has built a flight system and conducted multiple launches collecting simple data on the balloon payload's acceleration, position, orientation, internal and external temperatures, as well as photography and video. This poster reports on subsequent launches equipped with an on-board Geiger counter for cosmic ray studies, specifically targeting solar radiation. Initial results of analysis of cosmic ray data will be presented along with a discussion of future plans. [Preview Abstract] |
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KA.00073: Analyzing dynamically important differences between complex networks using reliability polynomial Yasamin Khorramzadeh, Stephen Eubank, Mina Youssef Characterizing networks in a way that is directly relevant to diffusion phenomena on the network is important, but difficult. We argue that the Network Reliability Polynomial is a characterization that folds together static measures like degree, modularity and measures of centrality into precisely the combinations that are most relevant to the dynamics. Thus knowledge of reliability can be used to infer structure, in the sense of network tomography. Furthermore, reliability concepts provide a new perspective for reasoning more generally about the consequences of structural changes. We demonstrate how to compare networks using a novel family of measures of an edge's contribution to particular aspects of diffusion dynamics on a network. The measures are analogous to betweenness, but are more directly related to specific dynamical phenomena. We focus here on phenomena of interest in network epidemiology, but the methods can easily be generalized to other diffusive processes on a network. [Preview Abstract] |
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KA.00074: Expression and Purification of Human Fibroblast Growth Factor-1 and Its in Vitro Interaction Studies with Kanamycin Tori Buckley Fibroblast growth factors (FGF's), work as modulators of different cell activities like mitosis, differentiation, survival etc. Among FGF's, Human FGF-1(hFGF-1) is the potent angiogenic factor, involved in the formation of new blood vessels in tissues. FGF-1 binds with heparin, which is glycosaminoglycan, and this complex further binds to Fibroblast growth receptors. Heparin potentiates the mitogenic activity of hFGF-1. Human FGF-1 activity is essential for cancer growth as it mediates the formation of blood vessels in the cancer tissues too. Recent studies found that an aminoglycoside antibiotic, Vancomycin, besides having antibacterial activity, also able to interact with fibroblast growth factors. These interactions of aminoglycoside are mainly because of structural resemblance to heparin. Vancomycin has been called as an anticancer antibiotic, because of its inhibiting effect on fibroblast growth factors in the cancerous tissues. This study is designed to study the possible interaction of kanamycin, another aminoglycoside, with fibroblast growth factor-1. Expression of FGF-1 in recombinant E.Coli was carried out, and expressed protein was purified using heparin affinity column chromatography. Both expression and purification were monitored through SDS-PAGE analysis. Conformational stability of protein was assessed through steady state fluorescence. Preliminary interaction study, thermal denaturation of FGF-1 in the presence and absence of kanamycin resulted in increased thermal stability FGF-1 with kanamycin compared to without. [Preview Abstract] |
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KA.00075: Are Those Diamonds In My White Wine? Veronica Smith, Edward Kintzel White wine is composed of a number of different compounds including tartaric acid, which is primarily found in grapes. Tartaric acid does also take the form of potassium tartrate (K$_{\mathrm{2}}$C$_{\mathrm{4}}$H$_{\mathrm{4}}$O$_{\mathrm{6}})$. Since this acid is only partially soluble, it does not necessarily completely dissolve in wine even though visual inspection shows no indication of their presence. Over time, and in particular at low temperatures, the acid crystallizes over time and ends up deposited on the bottom of the bottle. Wine diamonds themselves are natural and harmless. Using the Large Chamber Scanning Electron Microscope at the WKU Nondestructive Analysis Center, the surface morphology of ``diamonds'' that were harvested from the bottom a white wine bottle was carried out. Results will show the formation of pyramidal crystal structures of potassium tartrate. To complement this real-space imaging, a single crystal of potassium tartrate was studied using XRD. The sample was maintained at 298K during measurement, and the results indicate this is an orthorhombic crystal system for a rhombic-bipyramidal class with $a$~$=$ 7.6~{\AA}, $b$~$=$ 7.8~{\AA}, $c$~$=$ 10.6 {\AA}. [Preview Abstract] |
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KA.00076: Charged Fusion Product Diagnostic Detector Efficiency Study Carlos Lopez The results of experiments performed by a member of the Florida International University's experimental plasma physics research group will be presented. The work was done in preparation for the testing of a proton detection system implemented at the Mega Amp Spherical Tokomak at the Culham Centre for Fusion Energy in Oxfordshire, England. Monte Carlo methods were implemented in Python to model and calculate the solid angle of acceptance of the detectors leading to an efficiency calculation. The results of the computer simulation were confirmed using a radiation source in a vacuum chamber. This experiment was implemented in order to measure the counting rate of the detector, where particular interest was given to the change in said counting rate as the source position changed. The results of both works will be compared and presented. [Preview Abstract] |
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KA.00077: Single Step Antibiotic Mediated Synthesis of Gold Nanoparticles with Potent Antimicrobial Activity Hannah Rodgers, Rammohan Paripelly, Rajalingam Dakshinamurthy Gentamicin is an aminoglycoside antibiotic with bactericidal activity that works through binding the 30S subunit of the bacterial ribosome, interrupting protein synthesis. In this study gentamicin capped gold nanoparticles (GNP's) were synthesized through a biofriendly, single step process in an aqueous buffer. The GNPs were identified and size was determined with transmission electron microscopy. The average diameters of the particles are 50-10 nm. Further characterization was carried out with UV/vis spectrophotometry, Electron Dispersion Spectroscopy (EDS), and FTIR analysis. Elemental composition of GNP's was determined with EDS. Different antibacterial tests such as Turbidimetry, Spread plate assay, Tetrazolium salt based colorimetric assay and Micro-dilution Alamar blue assays were carried out on both Gram-negative and Gram-positive bacteria to determine the minimum inhibitory concentration of GNP's. Bacterial cross sectioning was performed to document the morphological changes on bacteria caused by the GNP's treatment. The GNP's antimicrobial activity was further confirmed with propidium iodide assay staining the afflicted bacteria. The results are promising since the concentration of GNP's required for minimum inhibition of bacteria was less than that which was compared to the original gentamicin. [Preview Abstract] |
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KA.00078: Undergraduates Administrating a High Performance Cluster William Dixon, Chad Garland, Larry Engelhardt, Ginger Brygelson, Galen Collier High performance computing is becoming a necessity to universities. The networking and configuration for a high performance cluster takes time to setup and configure for a safe environment for its users. We configure and add new software to make it easier on administrators, but also allow users as much access as possible without security issues. This project is support by the NSF EPSCoR Rll Track 1 cooperative agreement awarded to the University of South Carolina. [Preview Abstract] |
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KA.00079: Molecular Level Interaction of Human Fibroblast Growth Factor-1 (hFGF-1) with Anti-Diabetic Drug Hitesh Waghwani, Rammohan Paripelly Fibroblast growth factors work as modulators of different cell activities like mitosis, differentiation, survival etc. Within the FGF family FGF-1 is the potent angiogenic factor, involved in the formation of new blood vessels in tissues. FGF-1 is one of the targets in cancer inhibition and obesity due to its involvement in blood vessel formation in cancerous regions and adipose tissues. Many studies are going on inhibiting the FGF-1 mediated angiogenesis as FGF-1 plays a crucial role in angiogenesis. FGF-1 binds with heparin and this complex further binds to Fibroblast growth receptors. Heparin potentiates the mitogenic activity and increases the functional half life of the FGF-1. Phloridzin, an anti-diabetic drug, functions on the membrane surface of nephrons by preventing glucose re-absorption. Phloridzin resembles heparin in its structure as it is a glycosidic compound. This study is designed to study possible interaction of FGF-1 with Phlordzin. Human FGF-1 was expressed and purified. Preliminary experiments involving FGF-1 and phloridzin were carried out including fluorescence and trypsin digestion where the phloridzin protected the FGF-1 protein from denaturation by temperature and lysis by trypsin respectively. Protein-NMR studies have established the site of ligand binding. In future, isothermal titration calorimetry will be performed to determine the enthalpy of this ligand-protein interaction. [Preview Abstract] |
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KA.00080: Green Synthesis of Tetracycline Derivative Doxycycline Capped Gold Nanoparticles and Evaluation of its Antimicrobial Activity Varavoot Siriyutwatana, Ashley Mcdade, Jason Payne Nowadays, bacteria are rapidly developing mechanisms to become resistant to available antibiotics. Therefore, building up an effective alternative and its administration at a concentration, which will help in preventing bacterial resistance to drugs is important. We report a single step biofriendly synthesis of tetracycline derivative~doxycycline capped gold nanoparticles (D-GNPs). Gold nanoparticles act as an effective drug carrier hence capping of doxycycline on surface of GNPs will ensure targeted drug delivery. Effects of different parameters like solvent, temperature, reaction time on synthesis of D-GNPs were observed. Synthesized GNPs were then characterized by various analytical techniques like TEM, UV-vis spectroscopy, SEM, EDS and FTIR. TEM study showed that the resulting GNPs were spherical with a size within~15-20 nm. UV-vis spectroscopy showed the characteristic absorbance peak at 550 nm. Elemental and surface analysis was carried out by SEM, EDS and FTIR. The next step of our study involves evaluation of antimicrobial properties. For this conventional assays like spread plate assay and turbidimetry assay along with modern assays like XTT and alamar blue assay will be used. It is through this study that the potential use of D-GNPs in medicine can be assessed. [Preview Abstract] |
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KA.00081: Mississippi State Axion Search Kris Madsen The Mississippi State Axion Search (MASS) is an effort to improve the limit on the mass-coupling parameter of the Axion, a boson first postulated in the Peccei-Quinn theory as a solution to the strong CP problem in QCD. The collaboration is using a variation of the light shining through a wall (LSW) technique, taking advantage of the Primakoff Effect to identify Axions as an excess on a baseline of measured power inside a vacuum sealed, shielded cavity. A combination of dipole electro- and permanent magnets inside the cavity create a field of approximately .5 tesla and a 6cm lead wall partitions it. The signal, which has been optimized by Q factor to a frequency of 413.982 MHz, is sent through up to 150W of amplification before being broadcast and detected by an antenna on the far side of the cavity. The signal, as such, is integrated on a kHz time scale and amplified by a series of SR-510 lock in- and SR-550 pre amplifiers. The DAQ system, created using DASYLab, records the voltage at a kHz rate in coincidence with the maximum value of integration. The current focus of the collaboration is optimizing crucial parameters of the experiment in order to begin data collection and creating appropriate models to simulate and analyze the data. [Preview Abstract] |
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KA.00082: Light scattering measurement of phytoglycogen Nisha Lama, David Norwood, John Vercellotti We will describe the use of a multi-detector HPLC incorporating the DAWN EOS multi-angle laser light scattering (MALLS) detector to measure the properties of yeast phytoglycogen, which has many applications in baking, making beer and wine as well as in making cosmetics. Our measurements of a purified yeast phytoglycogen sample were intended to characterize the quality of the samples of yeast phytoglycogen by reporting properties such as molecular weight, RMS radius, contour and persistence length and polydispersity. Data and results obtained from the experiment will be presented. [Preview Abstract] |
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KA.00083: Analysis of Charge Fusion Product Rates: Initial Data from the Mega Amp Spherical Tokamak (MAST) Pierre Avila Tokamaks are used to create high temperature plasmas that are studied intensively with the use of various diagnostic equipment. Charged particles such as protons and tritons emitted from fusion temperature plasmas follow complicated trajectories due to their electromagnetic interaction with the magnetic fields inside the tokamak. The objective of this study is to detect these charged particles which give a different insight to the stability of plasmas generated within the tokamak. At the Mega Amp Spherical Tokamak (MAST) located at the Culham Centre for Fusion Energy (CCFE), solid state surface barrier detectors (SSBDs) were installed inside the vacuum to detect protons and possibly tritons. The SSBDs converted the particle's energy into electrical signals, which were then amplified and recorded by a Data Acquisition system (DAQ). Protons and tritons were successfully recorded after an initial data analysis. [Preview Abstract] |
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KA.00084: A Single Step Synthesis and Characterization of Nanowires {\&} Nanospheres for Catalytic Applications Fenil Chavda, Yogesh Kherde Nanoparticles have gained an immense interest due to its potency for a wide range of applications. Metals have been extensively used for catalytic reduction of p-nitrophenol in presence of NaBH$_{4}$. p-Nitrophenol is an environmental and biological toxic agent which is widely used in industries for a variety of purposes. Here, we report a single step, biofriendly synthesis of gold nanoparticles (AuNPs) with the help of a fluorescent dye called rhodamine-6G. We were successfully able to form AuNPs of different morphology i.e. gold nanowires and nanospheres by varying the concentration of rhodamine-6G. The synthesized gold nanostructures were characterized using transmission electron microscope (TEM), scanning electron microscope (SEM) and UV-Vis spectroscopy which proved the formation of rhodamine-6G containing gold nanostructures. Catalytic activity in reducing p-nitrophenol to p-aminophenol was assessed and compared for similar concentration of rhodamine-6G gold nanowires and nanospheres using UV-Vis spectroscopy. Finally, using the spectroscopic data, rate constant ($k)$ was calculated and compared for individual nanostructure to determine the effect of nanogold morphology on catalytic reduction activity. [Preview Abstract] |
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KA.00085: Construction and Analysis of an External Cavity Diode Laser with a Grating Mounted in Littrow Clint Mims, Eric Gardner, Charity Hawkins, R. Seth Smith Although unmodified diode lasers have some undesirable characteristics, they are still widely used because of their low cost and easy operation. In addition, they can be modified to improve their operation. In this experiment an external cavity was added to a diode laser by mounting a diffraction grating in a Littrow Configuration in order reduce the linewidth of the diode laser output. A thermoelectric cooler was used in order to control the temperature of the diode laser and a piezo electric crystal was added for tuning the wavelength of the diode laser. Tests were performed on the diode laser with and without the external cavity. The external cavity diode laser (ECDL) had a decreased bandwidth, fewer ``mode'' hops, and an increase in power. [Preview Abstract] |
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KA.00086: GPUs: What language do you speak? Tiffany Prosser, Larry Engelhardt We present the results of an undergraduate research project that explores the use of~Graphics Processing Units (GPUs) for scientific computing. ~In recent years GPUs have become popular for scientific computing due to their ability to provide massive parallelism (with thousands of cores) at a reasonable price. Since GPUs are still relatively foreign to most people, we present a comparison of a few basic GPU programming languages. These languages include CUDA and OpenACC. CUDA C is an extended version of C/C$++$. OpenACC (accULL and PGI) is a programming standard that allows FORTRAN and C/C$++$ programmers to easily take advantage of CPU/GPU systems. [Preview Abstract] |
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KA.00087: A Structural Determination of Spin Coated Chalcogenide Thin Films Justin Cook, Stanislav Slang, Miroslav Vlcek Technology of spin coated thin films of As$_{28}$S$_{72}$ and As$_{33}$S$_{67}$ compositions was developed. As opposed to thermal evaporation, spin coating is a quick, cost effective production method to produce amorphous thin layers. Using Raman spectroscopy, the structural features of virgin and exposed spin coated films were studied and compared to the structure of thermally evaporated films. Key structural differences were observed in the spectral regions associated with As-As and S-S homopolar bonds. In addition, upon exposure to 375 nm LED light, luminescence was observed within our spin coated samples, possibly indicating the presence of photoinduced polymerization or a similar phenomenon. [Preview Abstract] |
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KA.00088: The Isolation, Purification, and Genomic Analysis of Mycobacteriophage BusterBird12 Joseph Crafton The goal of the Genome Discovery and Exploration Program is to isolate and characterize novel mycobacteriophages from the environment in order to contribute information about their genome structure, geographic distribution, and morphology to the growing mycobacteriophage database. The host bacterium was \textit{Mycobacterium smegmatis}, a nonpathogenic relative of \textit{Mycobacterium tuberculosis}, the causative agent of tuberculosis. A soil sample was collected and enriched to create an environment favoring mycobacteriophage proliferation. Mycobacteriophages were detected by looking for plaque formation, or zones of clearing, on a lawn of host cells. A single plaque was chosen and purified multiple times by a modification of the streak plate technique. The purified phage was named BusterBird12. Electron microscopy revealed that BusterBird12 had an icosahedral capsid and a tail. The average capsid diameter is 52.78 nm, the average tail length is 168.75 nm, and the average tail width is 12.5 nm. Restriction analysis of the purified genomic DNA suggested that BusterBird12 is a member of the K cluster of mycobacteriophages. [Preview Abstract] |
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KA.00089: Direct Aminoglycoside Coated Gold Nanoparticles Synthesis, Characterization and Antibacterial Susceptibility Testing Rammohan Paripelly, Rajalingam Dakshinamurthy, Dillon Pender Need for novel, innovative strategies for developing antibiotics is becoming a necessity due to an increasing number of rapidly evolving multi drug resistant bacteria threats. Antibiotic encapsulated gold nanoparticles (GNP's) are one such strategy showing promise. Kanamycin is an aminoglycoside antibiotic with bactericidal activity that works through binding the 30S subunit of the bacterial ribosome, interrupting protein synthesis. In this study we report development of Kanamycin coated gold nanoparticles (Kan-GNPs) which has highly effective, dose dependent antibacterial activity). The method employed in this study for synthesizing Kan-GNP's is an entirely eco-friendly, single step reaction, carried out within an aqueous buffer. The GNPs were identified and size was determined with transmission electron microscopy. The average diameter of the particles is 15 $\pm$ 5 nm. Further characterization was carried out with UV/vis spectrophotometer; Electron dispersion spectroscopy (EDS) and FTIR analysis. We have tested the antibacterial activity of Kan-GNP's against multiple strains of bacteria, both Gram-positive and Gram-negative, and have found Kan-GNP's to be highly efficient against all tested strains. [Preview Abstract] |
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KA.00090: Minowski's Spacetime in Heterogeneous Medium Florentin Smarandache Let's suppose that both locations $L_{1}(x_{1}, y_{1}, z_{1})$ and $L_{2}(x_{2}, y_{2}, z_{2})$ are under water, somewhere in the Pacific Ocean. Now light in the water has a smaller speed (c$_{\mathrm{w}})$ than in vacuum, i.e. $c_{w}$\textit{ \textless c}. Therefore within the same interval of time $t_{2\thinspace }- t_{1}$, light travels in the water a lesser distance than $L_{1}L_{2}$. Thus $d(E_{1}, E_{2})$ has a different representation now $L_{1}L$. And, if instead of water we consider another liquid, then $d(E_{1}, E_{2})$ would give another new result. Therefore, if we straightforwardly extend Minkowski's spacetime for an aquatic only medium, i.e. all locations $L_{i}(x_{i}, y_{i}, z_{i})$ are under water, but we still refer to the light speed but in the water $(c_{w})$ then the coordinates of underwater events $E_{w}$ would be $E_{w}(x_{i}, y_{i}, z_{i} ,c_{w}, t_{i})$ and Minkowski underwater distance would be: \[ d_{w}^{2}(E_{w1} ,E_{w2} )=c_{w}^{2}(t_{2} -t_{1} )^{2}-[(x_{2} -x_{1} )^{2}+(y_{2} -y_{1} )^{2}+(z_{2} -z_{1} )^{2}] \] But if the underwater medium is completely dark it might be better to consider the speed of sound in order to communicate (similarly as submarines use sonar). Let's denote by s$_{\mathrm{w}}$ the underwater speed of sound. Then the underwater events $E_{ws}(x_{i}, y_{i}, z_{i} ,s_{w}.t_{i})$ with respect to the speed of sound has the Minkowski underwater distance: \[ d_{ws}^{2}(E_{ws1} ,E_{ws2} )=s_{w}^{2}(t_{2} -t_{1} )^{2}-[(x_{2} -x_{1} )^{2}+(y_{2} -y_{1} )^{2}+(z_{2} -z_{1} )^{2}] \] Similarly for any medium $M$ where all locations $L_{i}(x_{i}, y_{i}, z_{i})$ are settled in, and for speed of any waves W that can travel from a location to another location in this medium. [Preview Abstract] |
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KA.00091: Designing a Unique Therapeutic Agent Involving Gold Nanoparticles Capped with Ceftazidime for Potent Antibacterial Applications Monic Shah, Will Hamilton, Varavoot Siriyutwatana There is a desperate need for making new antibiotics in response to the soaring increase in cases of multi-drug resistant (MDR) bacteria which are prevalently known as ``Superbugs.'' We have tried to design an effective antibacterial agent involving gold nanoparticles (AuNPs) capped with an antibiotic (ceftazidime). By keeping twelve principles of ``green chemistry'' in mind, an unique, single step process, unlike conventional methods was fabricated for making AuNPs using the combine reducing and capping ability of ceftazidime to yield ceftazidime capped gold nanoparticles (C-AuNPs) which were then characterized using various analytical techniques such as transmission electron microscope (TEM), scanning electron microscope (SEM) and UV-Vis spectroscopy to determine its morphology. Efficiency of C-AuNPs was assessed using several antibacterial assays such as turbidimetry, spread plate method and XTT assay. A variety of bacterial strains involving both Gram-positive and Gram-negative were used for above assays. The minimum inhibition concentration (MIC) of C-AuNPs, obtained from the assays was compared with the MIC of ceftazidime pure drug in order to evaluate the superiority of C-AuNPs over ceftazidime pure drug. [Preview Abstract] |
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KA.00092: Green Synthesis and Evaluation of Catalytic Activity of Mono, Di and Trisaccharide Capped Gold Nanoparticles Yogesh Kherde, Fenil Chavda, Jason Payne, Rajalingam Dakshinamurthy Gold nanoparticles have gained a lot of interest due to their wide applications in the field of biomedical and pharmaceutical. The applications of nanoparticles are due to their unique properties when they are reduced to their nanoscale size range. We present a novel single step biofriendly process for synthesis of Fructose (monosaccharide), Sucrose (disaccharide) and Raffinose (trisaccharide) capped gold nanoparticles, where in sugar is directly capped onto gold without the use of any secondary capping/stabilizing agent. Our study was mainly focused on the effect of different lengths of sugars on the formation and catalytic activity of sugar capped GNPs. Characterization of nanoparticles is done by using various analytical techniques such as transmission electron microscope, FTIR, UV-Vis spectroscopy and SEM-EDS. We evaluated the catalytic activity of sugar capped GNPs by using nitrophenol reduction assay at different temperature. From the average reaction rate constants at three different temperatures we determined the activation energy. The kinetic data indicates that fructose GNPs have the highest catalytic activity, while raffinose shows the lowest catalytic activity. This difference in the catalytic activity may be attributed to the size of ligand on gold surface which affects the surface to volume ratio. [Preview Abstract] |
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KA.00093: Charge Fusion Product Trajectory Simulations Omar Leon Spherical tokamaks use magnetic fields to produce and confine plasmas, which are hot ionized gases. Due to the magnetic properties of plasmas and the magnetic fields of tokamaks, current diagnostics focus on detecting neutral particles. When the temperature of plasmas, composed of hydrogen isotopes, reach approximately 100 million degrees Celsius, the isotopes react with one another emitting protons and other charged particles. These reactions are called fusion reactions. A new diagnostic, the charged fusion product diagnostic, is geared towards detecting protons, tackling the issue of particles interacting with magnetic fields, in order to expand the methods of studying plasmas. However, the complex nature of plasmas and the magnetic fields makes calculating many plasma properties analytically impossible. A program called the Orbit Code was developed and tailored to the requirements of the diagnostic in order to numerically calculate charged particle trajectories in the tokamak's plasmas. This Orbit Code was used to determine the trajectories of protons emitted from fusion reactions inside in the Mega Amp Spherical Tokamak (MAST) located at the Culham Centre for Fusion Energy (CCFE). Using these predictions, the diagnostic can be placed in the locations that most effectively samples the plasmas. [Preview Abstract] |
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KA.00094: Development of NSECT Imaging System with Rotation Modulation Collimator Andrew Staggs, Ivan Novikov In Neutron Stimulated Emission Computed Topography (NSECT), a beam of fast neutrons is used to excite nuclei of the target area. During de-excitation the nuclei emit gamma rays with specific energies. The detection of these gamma rays allows for the identification of elements present in the target. Recently, it was proposed to use a rotational modulation collimator (RMC) to add imaging capability to the NSECT-based system. The NSECT based system which employs the d-T neutron generator and the 3"x3" HPGe detector is currently under development at WKU. The current status of the system development is discussed. [Preview Abstract] |
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KA.00095: Identification of Upward-going Muons for Dark Matter Searches at the NOvA Experiment Liting Xiao We search for energetic neutrinos that could originate from dark matter particles annihilating in the core of the Sun using the newly built NOvA Far Detector at Fermilab. Only upward-going muons produced via charged-current interactions are selected as signal in order to eliminate backgrounds from cosmic ray muons, which dominate the downward-going flux. We investigate several algorithms so as to develop an effective way of reconstructing the directionality of cosmic tracks at the trigger level. These studies are a crucial part of understanding how NOvA may compete with other experiments that are performing similar searches. In order to be competitive, NOvA must be capable of rejecting backgrounds from downward-going cosmic rays with very high efficiency while accepting most upward-going muons. [Preview Abstract] |
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