Bulletin of the American Physical Society
Fall 2019 Meeting of the Ohio-Region Section and the Michigan Section of the American Association of Physics Teachers
Volume 64, Number 15
Friday–Saturday, October 11–12, 2019; Flint, Michigan
Session A02: OSAPS Poster Session |
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Chair: Corneliu Rablau, Kettering University Room: Kettering University Academic Building 3342 |
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A02.00001: Hydrothermal Synthesis of Carbon doped Sodium Tantalates. Christopher Saunders, Roma Karna, Priya Karna, Deepa Guragain, Sunilu Karna Experiments were conducted to optimize the growth parameters for doping of sodium tantalates with carbon in energy efficient hydrothermal process. We have successfully grown sodium tantalate nanocubes at low temperature of 140$^{\mathrm{o}}$ C for 15 hours in rich alkaline atmosphere and able to dope them with carbon to enhance their visible light photocatalytic activities. Sodium tantalate contains perovskite structure of cubic crystal with an average size of 80 nm. The morphological, compositional, structural, thermal properties, band gap, and photocatalytic activities of as-synthesized doped and undoped sodium tantalate (NaTaO$_{\mathrm{3}})$ nanocubes were characterized by scanning electron microscope (SEM), x-ray powder diffraction (XRD), thermal gravimetric analysis (TGA), ), Fourier Transform Infrared Radiation Spectrophotometer (FTIR) and UV-vis spectrophotometer. The optical bandgap of undoped sodium tantalates were found to be 4 eV and upon doping with carbon their bandgap reduces to 3.6 eV. [Preview Abstract] |
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A02.00002: Temperature dependent photoluminescence and reflectance studies of CsPbBr$_{\mathrm{3}}$ Quantum Dots. Lyall Alwafi, Gavin Trevorrow, Amlan Datta, Biplob Barman Metal halide perovskite-based semiconductor quantum dots (QD) have been extensively studied, as a means to explore potential applications by harnessing their excellent optoelectronic properties. In this work, we used temperature dependent (10 K -- 290 K) photoluminescence (PL) spectroscopy, using CW laser (with excitation powers of 0.74 \textmu W and 0.16 \textmu W) operating at two different excitations wavelengths 3.06 eV and 2.75 eV. The PL emission results in an asymmetric Gaussian which can be decomposed into two peaks at 2.392 eV and 2.410 eV. Besides PL, we also performed temperature dependent reflectance measurements which reinforces the dual emissive nature of these QDs. While the low energy feature is attributed to free exciton emission, the high energy feature could be a result of disorder or imperfection related mechanisms. [Preview Abstract] |
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A02.00003: Systematic Study of the Effect of Incorporation of Carbon Nanotubes into Ge$_{\mathrm{\mathbf{x}}}$ Se$_{\mathrm{\mathbf{1-x}}}$ Glass System f1 Chari Ramkumar, John Rademacher, Mehdi Millot, David Hellman, Jake Anderson, Wayne Bresser We successfully synthesized Ge$_{\mathrm{x}}$Se$_{\mathrm{1-x}}$ (x $=$ 0.225) glass samples and doped the samples with commercially produced (Protein Mods) carbon nanotubes (CNTs). We investigated the glass transition temperature (T$_{\mathrm{g}})$ using Modulated Differential Scanning Calorimetry (MDSC). The glass samples without the CNTs have a a T$_{\mathrm{g}}$ of \textasciitilde 220\textdegree C and the T$_{\mathrm{g}}$ was found to be independent of starting materials from different suppliers as well as water-bath temperature (Fig. 1). CNTs, being a very hygroscopic material as well as oxygen absorbing material, needed to be cleaned under vacuum with the hot water-bath. We found that the T$_{\mathrm{g}}$ decreases when 5{\%} and 10 {\%} CNTs by mass is added to the glass samples as compared to the base Ge$_{\mathrm{x}}$Se$_{\mathrm{1-x}}$ glass. The decrease in T$_{\mathrm{g}}$ indicates the occurrence of an intermediate phase (reduced-stress glass phase) at lower temperature, which could be potentially useful in material science applications. [Preview Abstract] |
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A02.00004: Studying shunted SQUID measurements in a controlled magnetic field setting Jacob Adamczyk, Clemens Winkelmann In recent years, the study of nanodevices such as superconducting quantum interference devices (SQUIDs) have increased in popularity due to their usage in magnetometry, for example in the magnetism of nanoparticles. Particularly, SQUIDs have the capability of measuring small changes in magnetic field and changes in magnetization at the level of a few Bohr magnetons. Electrical measurements of a SQUID, which is shunted with an on-chip Au resistor, are shown in the normal and superconducting states, at temperatures down to 4 K. Stable critical currents and hysteretic voltage-current characteristics are observed. The SQUID holder is fitted within a custom-made solenoid to control the magnetic flux passing through the SQUID. Data and corresponding theory showing the dependence on the device's critical current on magnetic field is presented as well as a discussion of these results. [Preview Abstract] |
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A02.00005: Investigation of the magnetic and magnetocaloric properties of Si-doped Al$_{\mathrm{1.2-x}}$Si$_{\mathrm{x}}$Fe$_{\mathrm{2}}$B$_{\mathrm{2}}$ alloys prepared by drop casting Md Sakhawat Hossain Himel, Mahmud Khan In terms of efficiency, reliability, and environmental friendliness (reducing the green-house effect and global warming) the solid state magnetic cooling technology supersedes the currently employed gas compression based cooling systems. A solid state refrigerator exploits the magnetic properties of a special group of materials known as the magnetocaloric materials. The speciality of these materials is that an application of an external magnetic field can significantly change their temperature. Here, we have investigated the magnetic and magnetocaloric properties of a series of Si-doped Al$_{\mathrm{1.2-x}}$Si$_{\mathrm{x}}$Fe$_{\mathrm{2}}$B$_{\mathrm{2}}$ (0 $\le $ x $\le $ 0.25) compounds by x-ray diffraction and dc magnetization measurements. The samples were prepared by arc-melting and annealing techniques. The x-ray diffraction patterns confirmed that all samples exhibited the single-phase, \textit{Cmmm}-type orthorhombic crystal structure. A second-order ferromagnetic phase transition was observed near room temperature for all samples.~A maximum peak magnetic entropy change of 7.39 Jkg$^{\mathrm{-1}}$K$^{\mathrm{-1\thinspace }}$was observed in the samples for a field change of 50 kOe. We will present the magnetic properties of these materials in details. [Preview Abstract] |
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A02.00006: Formation of Palladium (II) Oxide within Titanium Dioxide Electrospun Nanofibers: Combined Raman and X-ray Diffraction Study Daniel Isaacs, Patrick McManus, Nenad Stojilovic, Maja Scepanovic, Mirjana Grujic-Brojcin, Natasa Tomic, Laila Shahreen, George Chase TiO$_{\mathrm{2}}$-PdO composite submicron fibers were produced using electrospinning method. The morphology of the fibers was probed using Scanning Electron Microscopy, whereas Raman Spectroscopy and powder X-Ray Diffraction experiments were used for probing the crystalline phases of pure TiO$_{\mathrm{2}}$ and TiO$_{\mathrm{2}}$ -- PdO fibers. In particular, the effects of annealing time (at 600 $^{\mathrm{o}}$C) on the crystal structure and the role of embedded PdO were investigated. The results of Raman scattering measurements have shown dominant anatase TiO$_{\mathrm{2}}$ phase in all samples. The crystallinity of anatase phase, as well as the appearence of rutile and brookite$_{\mathrm{\thinspace }}$phases, depend on annealing and doping conditions. The existence of PdO within TiO$_{\mathrm{2}}$ stabilizes its anatase phase, and the Raman modes ascribed to PdO become more pronounced with annealing. The combination of Raman and X-Ray diffraction techniques proves to be a powerful tool in characterizing these materials. [Preview Abstract] |
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A02.00007: Observation of two superconducting phase transitions in NbNi2-xCuxSn Heusler alloys Brandon Reese, Mahmud Khan Superconductivity is one of the many exotic properties exhibited by Heusler alloys. Currently, Ni-based Heusler alloys are of great interest since Ni is ferromagnetic. NbNi2Sn is a Heusler alloy which has 29 valence electrons per formula unit, 7.25 valence electrons per atom, and exhibits a superconducting phase transition at TC $=$ 3.4 K. The BCS type II superconductivity in NbNi2Sn and other Heusler compounds are believed to be associated with the van Hove singularities observed in the electronic structure of the materials. It is well established that the electronic and magnetic properties of Heusler compounds can be controlled by manipulating the constituent elements of the respective compounds, particularly by elemental doping. Recent research has shown that the superconducting properties of selected Heulser compounds can be systematically controlled by elemental doping. Motivated by these observations we have performed an experimental study on the superconducting properties of partially Cu doped Ni2-xCuxNbSn materials. Characterization involves the study of various structural, magnetic, and electrical properties associated with the compounds. All compounds exhibited an L21 Heusler cubic structure. Interestingly, two superconducting transitions were observed in all compounds (including Ni2NbSn) at temperatures near TC1 $=$ 17.8 K, and TC2 $=$ 3.4 K. Magnetization data has confirmed type-II superconductivity for each sample at both transition temperatures. [Preview Abstract] |
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A02.00008: Pentacene Thin Film Growth Bradley Lockhart, Jessica Bickel Pentacene is a common organic semiconductor with a relatively high conductivity that increases when crystallized. The pentacene was studied by depositing it on highly ordered pyrolytic graphite (HOPG) using a thermal evaporator and characterizing it with scanning tunneling microscopy (STM). The initial depositions suffered from inconsistent growth rate readings. We determined that the inconsistency was due to the fact that while the thermal evaporator chamber is under high vacuum, the daily pressure varied between 1 and 7x10-5 torr during the evaporation. These variations in pressure had a impact on the growth rate of the pentacene while at the same temperature. We subsequently developed a method to measure the growth rate immediately before the deposition circumventing the issue of the variable pressure. This was done by opening the shutter of the thermal evaporator to a specific angle so that the growth rate could be measured without actually depositing any material on the HOPG. During the study of the STM data, several images showed the deposited pentacene either forming into clumps, or into seemingly more ordered track-like patterns. These images were analyzed to find the dimensions of these structures and compared to previously gathered pentacene data from other groups. [Preview Abstract] |
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A02.00009: Adsorption transition for a polymer chain in a narrow slit Norah Ali, Mark Taylor Here we study the adsorption of a confined flexible polymer chain to an attractive surface. The polymer is end-tethered to an attractive plane which forms one wall of a slit-like pore. At low temperature the polymer will be completely adsorbed on to the attractive wall while at high temperature the polymer will be desorbed and in a random coil configuration. We use a Wang-Landau simulation algorithm to compute the density of states of this system from which we can construct the complete thermodynamic behavior. Our main interest is how the width of the slit affects the location of the adsorbed-to-desorbed transition. Geometric confinement usually favors a compact state over an expanded state [1], however, here we find that as the slit width is decreased the desorbed (expanded) state is favored (i.e., the transition moves to lower temperature). For extremely narrow slits (where we have a pseudo 2D system) we find a crossover to stabilization of the adsorbed (compact) state. We also study the effects of chain length on the location of this transition. [1] Taylor, Macromolecules 50, 6967 (2017). [Preview Abstract] |
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A02.00010: Solvent induced unfolding of a polymer chain Elizabeth Breen, Mark Taylor Many bio-molecules fold into specific 3D shapes that are closely associated with their functions. For many small proteins this folding transition follows an all-or-none process analogous to a first-order phase transition. Here we study a simple homo-polymer model that undergoes a similar type of folding transition and thus may provide some insight into the underlying physics of protein and bio-molecule folding [1]. In particular we investigate solvent induced folding or unfolding of a chain in a dense solvent environment. We study a flexible square-well-sphere chain in an explicit solvent of hard spheres. There is an adjustable attractive interaction between the solvent and the chain that mimics the effects of changing the solvent pH or concentration of a chemical denaturant. Starting from conditions favoring a folded polymer, increasing the chain-solvent interaction causes the solvent molecules to "stick to" or solvate the chain. This solvation effect can disrupt the folded chain structure, driving the chain into an open, unfolded conformation. Here we use both Wang-Landau and Metropolis Monte Carlo simulation techniques to study this isothermal, solvent-driven chain unfolding process. [1] Taylor, Paul, and Binder, J. Chem. Phys. 145, 174903 (2016). [Preview Abstract] |
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A02.00011: Polymer chain folding in spherical nano-confinement Antonia Sikon, Mark Taylor Nano-scale confinement of a polymer chain results in a loss of conformational entropy. For a chain that can fold into a compact native state, such confinement reduces the number of possible unfolded configurations, thereby stabilizing the folded state and shifting the location of the folding transition. Here we investigate these confinement effects for a flexible polymer confined within a rigid sphere of diameter D. We study a square-well-sphere chain that undergoes a first-order-like folding transition analogous to the all-or-none folding characteristic of many small proteins [1]. We construct the partition function for this chain under confinement using a Wang-Landau simulation approach. The resulting temperature vs confinement length D phase diagram shows stabilization of the folded state with decreasing D and the possibility of confinement induced isothermal folding [2]. The folding transition remans first-order-like even in extreme confinement with a free energy barrier that is little affected by changes in D. [1] Taylor, Paul, and Binder, J. Chem. Phys. 145, 174903 (2016); [2] Taylor, Macromolecules 50, 6967 (2017). [Preview Abstract] |
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A02.00012: Effect of nanostructuring in Mn$_{\mathrm{2}}$Ni$_{\mathrm{1+x}}$Ga$_{\mathrm{1-x}}$ magnetic intermetallic system Sutapa Biswas, Mahmud Khan, Tiago Schaeffer The exchange bias effect (EB) is a phenomenon, which is signified by a shift of the magnetic hysteresis loop along the magnetic field axis. A group of Mn-rich Heusler alloys also exhibit exchange bias properties. EB effects in these alloys are observed while they are in their polycrystalline bulk form. The EB effect in Heusler alloys is also attributed to the coexisting ferromagnetic (FM) and antiferromagnetic (AFM) interactions. Mn$_{\mathrm{2}}$NiGa is a Heusler alloy where the Mn moments show both parallel and anti-parallel alignments. The material does not exhibit any EB effect. Here, we have systematically investigated the magnetic and EB properties of Mn$_{\mathrm{2}}$Ni$_{\mathrm{1+x}}$Ga$_{\mathrm{1-x}}$ (0 $\le $ x $\le $ 0.60). As x exceeded 0.2, EB started to appear in the system. EB-field as large as 4000 Oe was observed in this system of material. The samples were fabricated by arc melting and annealing techniques. Nanostructured ribbons were prepared for selected compositions by melt spinning technique. The effect of annealing temperature on the EB properties of the ribbons comparing to the bulk material properties will be discussed and presented. [Preview Abstract] |
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A02.00013: Achieving Flat Gold Surfaces for the Organization of Organic Molecules Jacob Martin, Dr. Jessica Bickel Organic electronics are interesting but suffer in competition with inorganics due to their lower conductivity. Crystallizing organic semiconductors can increase their conductivities. Organic molecules can by crystallized via self-assembly driven by the topography and chemistry of an atomic surface reconstruction. This work examines the Au(111) surface, which has a herringbone reconstruction. The first step to using such a surface for self-assembly is developing a method to create atomically smooth Au(111) surfaces. One method to smoothen surfaces is annealing, which allows the atoms to rearrange into a lower energy state. In this work, a propane torch is used to anneal the sample at $710\pm10$C for two minutes, and then three minutes at $410\pm10$C. This yields larger and flatter terraces compared to the unannealed material. The unannealed gold had mounds with no flat areas and a max depth of 7.6 nm. The annealed Au(111) had flat terraces, 13-30 nm in size, with step heights in the order of .235 nm, which matches the interplanar spacing for Au(111). In the future we will optimize this process to achieve large terraces by adjusting the temperatures and times used. [Preview Abstract] |
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A02.00014: The photoelectric effect -- project-based undergraduate teaching and learning optics through a modern physics experiment redesign Corneliu Rablau, Uma Ramabadran, Brendan Book, Robert Cunningham The photoelectric effect is a cornerstone textbook experiment in any Modern Physics or Advanced Laboratory course, designed to verify Einstein's theory of the photoelectric effect, with the implicit determination of an experimental value for Planck's constant and the demonstration of the particle nature of light. The standard approach to the experiment is to illuminate the light-sensitive cathode of a vacuum-tube photocell with monochromatic light of known wavelengths; a reversed-voltage is then applied to the photocell and adjusted to bring the photoelectric current to zero. The stopping voltage is then plotted as a function of the inverse wavelength or frequency of the incident light, and Planck's constant is determined from the slope of the graph. Additionally, a value for the work function of the photocathode can be extracted from the intercept. The commercial apparatus for the experiment is available from a number of vendors (PASCO, Leybold) in various forms, degrees of performance and cost. However, designing and assembling a photoelectric effect experiment apparatus can in itself be a valuable experiential project-based undergraduate learning opportunity in Optics involving both fundamental light and optics theory and practical optics and opto-mechanical design aspects. This presentation details a project undertaken in the Applied Physics/Engineering Physics programs at Kettering University for a redesign of an existing photoelectric effect \textit{apparatus} through an undergraduate student thesis. [Preview Abstract] |
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A02.00015: Fluorescence cross correlation spectroscopy (FCCS) to reveal molecular mechanism of lipolysis Sonali Gandhi, Christopher Kelly The dynamics of lipids and proteins are crucial in the mechanisms of cellular functions. We aim to develop novel methods for revealing the interactions between lipolysis associated proteins adipose triglyceride lipase (ATGL), perilipin (PLIN), and alpha beta hydrolase domain-containing protein 5 (ABHD5). We have applied fluorescence cross-correlation spectroscopy to study the interactions between these lipids and proteins. We focus a super-continuum laser (400-700 nm) to excite fluorophores within a small detection volume, the fluorescent proteins that diffuse through the diffraction limited spot will emit a fluctuating signal. The fluorescence emission is chromatically spread by passing via prism and collected by a CMOS. The intensity vs time of each color channel are extracted through linear least-square fitting of each camera frame and temporally correlated to reveal the characteristic dynamics of the proteins. From auto- and cross-correlation functions, we measure the diffusion rates and fraction correlated. We use model membranes of giant unilamellar vesicles (GUVs) locked inside agarose gel to study characteristic and interaction between these proteins in presence of phospholipid with and without the ligand. Results from this study will enable us to understand lypolysis. [Preview Abstract] |
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A02.00016: Unconventionally blocking photons in a three-mode optomechanical cavity with Kerr type nonlinearity Avtej Sethi, Ashwin Mishra The production of light states with a fixed number of photons is useful for several quantum technologies including quantum cryptography and quantum imaging. Typically, cavity QED systems with strong light-matter interaction can serve as photon turnstiles \footnote{Science, 319, 5866, 1062-1065 (2008).} making use of the conventional photon blockade. It turned out that the same goal can also be achieved at the two-photon level using the unconventional photon blockade (UPB) \footnote{Phys. Rev. Lett. 104, 183601 (2010).} while making use of the destructive interference between photon pathways. Recently, Sarma et al. \footnote{Phys. Rev. A 98, 013826 (2018). } have analyzed the optimal conditions to achieve the UPB in a single three-mode optomechanical cavity subjected to a weak drive. In this work, we extend their work to two such optomechanical cavities where optical modes of the cavities are coupled. With two-photon truncation, we analytically address the question that how the cavity-cavity coupling can impact the optimal parameter regime to observe UPB. [Preview Abstract] |
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A02.00017: Optomechanical Spin-Orbit Coupling Ariel Xie It is known that the angular momentum of light can be transferred to a transparent isotropic sphere, therefore affecting its spin and trajectory. In this work, we consider angular momentum transfer to an anisotropic sphere, and predict the perturbation to the trajectory due to the anisotropy. [Preview Abstract] |
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A02.00018: Hyperdoping Silicon For Infrared Detection and Night Vision Applications Peter Hadchiti, Yining Liu, Wenjie Yang, Quentin Hudspeth, Andrew Sarangan, Imad Agha, Jeffrey Warrender, James Williams, Jay Mathews Infrared (IR) detection has many commercial applications such as in night vision and fiber optic communications. Current night vision devices are large and low-res, and can't be integrated with consumer electronics. Being able to make silicon (Si) based IR detectors would make it substantially cheaper and easier to integrate IR imaging and other optical systems into consumer devices. Si is useful for electronic devices, but isn't a good material for IR imaging because it doesn't efficiently absorb IR light. By adding impurities to Si in a process called hyperdoping, IR absorption can be induced, which could lead to Si-based low-light imaging. It's been shown that hyperdoped Si can detect IR light, but only at low efficiency. Our research has been in manipulating the doping and fabrication processes to increase the efficiency of Si-based IR detectors.~ We have fabricated new photodetectors based on these improvements, and I measured the optical and electrical properties of these devices. The new devices show improvement of nearly two orders of magnitude in the infrared photoresponse from what has already been shown, demonstrating this material's potential for infrared imaging. [Preview Abstract] |
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A02.00019: Activity of DdiTLP4 on RNAs in Dictyostelium Discoideum Carlos Owusu-Ansah, Ralf Bundschuh RNA polymerases usually add nucleotides to the 3'end of RNAs, but TLPs (Thg1-like proteins) add nucleotides to the 5'ends of RNAs. Our investigation is part of the broad attempt to understand this behavior. We worked with DdiTLP4, a TLP found in Dictyostelium. Our collaborators cultivated two sets of Dictyostelium samples: one set contained cells with suppressed levels of DdiTLP4 and the other contained normal cells. A range of nucleotides at the 5'ends of RNAs in the samples were sequenced. Our role in this investigation was to analyze RNA reads to determine DDiTLP4 activity. Since we were looking for changes in 5'ends resulting from direct DdiTLP4 activity, we discarded differences in 5'ends which resulted from differential gene expression. This was accomplished by grouping RNAs which aligned to neighboring positions of the genome and analyzing each batch separately. Differences in 5'end counts due to the differential expression of genes manifest as the scaling of the counts of one treatment relative to the other. Conversely, differences in 5'end resulting from direct DdiTLP4 polymerase activity change the fractional composition of the knockdown batches relative to the wildtype batches. [Preview Abstract] |
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A02.00020: Avian incubation period and embryonic metabolism from egg geometry via conservation of energy Scott Lee, Joshua Thomas, Max Cooley, Richard Irving Conservation of energy is applied to the growth of an avian embryo inside its egg. The resulting theoretical model predicts the incubation period, embryonic metabolism and hatching mass of the bird using the surface area and volume of the egg of that species. Our model makes three assumptions: 1.) the hatching mass is related to the volume of the egg, 2.) the maximum metabolic rate of the embryo is related to the surface area of the egg, and 3.) the adult mass is related to the volume of the egg. These assumptions are tested by evaluating data for extant birds. This model can be applied to any avian species for which an intact egg exists, including extinct species. The embryonic metabolism and incubation period for two extinct species, including the giant elephant bird (\textit{Aepyornis maximus}), are calculated. [Preview Abstract] |
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A02.00021: Avian humeral bone strength and flight with implications for eumaniraptoran dinosaurs Scott Lee, Joshua Thomas, Rong Liu The strength of humerus bone is evaluated for 17 species of extant birds with varying mass by measuring its section modulus. The least massive bird is \textit{Regulus calendula} (0.0058 kg) while the most massive is \textit{Cygnus olor} (8.959 kg), a range of more than a factor of 1500 in mass. The humeral section modulus is found to be proportional to the mass of the bird. Five extinct birds of the Mesozoic are found to have humeri of the same strength (for their mass) as extant birds. The humeral section modulus of 14 eumaniraptoran dinosaurs are tested and five species are found to have humeri strong enough for flight. [Preview Abstract] |
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A02.00022: Quantitative \textmu MRI and PLM Study of Rabbit Cartilage at Microscopic Resolutions Syeda Batool, Yang Xia The gradual degradation of cartilage leads to osteoarthritis, a major musculoskeletal disease affecting millions of adults. This study aimed on the quantification of T2, T1$\rho $ and T1 relaxation times in humeral and femoral cartilage of rabbit using \textmu MRI, and complementing the results with Polarized microscopy (PLM) at highest possible resolution. We plan in the future to study cartilage from the rabbit model of osteoarthritis. Multiple (1.8\texttimes 2\texttimes 2.5mm\textthreesuperior ) cartilage-bone specimens were harvested from humeral and femoral heads and imaged in \textmu MRI at 9.75\textmu m resolution. After \textmu MRI, 6.0\textmu m thick sections were cut from each sample to generate quantitative PLM images at 1\textmu m resolution. Quantitative \textmu MRI relaxation data and PLM fibril structural data showed distinct features in tissue properties at different depths of cartilage, different in individual histological zones. The thicknesses of the histological zones in \textmu MRI and PLM were successfully obtained. This is the first correlated and quantitative MRI and PLM study of rabbit cartilage at sub-10\textmu m resolutions. The establishment of the characteristic features of rabbit cartilage based on multidisciplinary imaging techniques would provide a solid foundation for future utilization of the rabbit model in the OA investigation. [Preview Abstract] |
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A02.00023: Insights into Mechanotransduction: Effects of Unequal Anisotropy Ratios in Cardiac Muscle Dilmini Wijesinghe, Bradley Roth The properties of cardiac muscle are anisotropic: they depend on direction along or across the myocardial fibers. Studying the effects of anisotropy is essential for understanding the behavior of cardiac muscle. The bidomain model represents the intracellular and extracellular spaces separately, so ``unequal anisotropy ratios'' means the degree of anisotropy is different in the two spaces. In previous studies, analyzing unequal anisotropy ratios of the conductivity using the electrical bidomain model revealed new and unexpected mechanisms of excitation of action potential wave fronts by a pacemaker. In this study, analyzing unequal anisotropy ratios of the mechanical moduli using the mechanical bidomain model explores how the tissue grows and changes in response to mechanical forces: mechanotransduction. A coupled set of partial differential equations representing the bidomain model was solved numerically. These simulations predict that the distribution of mechanotransduction is sensitive to the condition of unequal anisotropy ratios, particularly when the fiber direction varies throughout the tissue. These results have implications for the study of growth and remodeling of the heart during diseases such as cardiac hypertrophy. [Preview Abstract] |
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A02.00024: Quantifying optical properties of hemozoin for the rapid detection of malaria Kyle Blasinsky, Amanda McGreer, Robert Deissler, Danielle Kara Hemozoin, a byproduct of plasmodium, is the basis of a new approach for efficient, cost-effective malaria detection. Clinical success of malaria detection with a magneto-optical device (MOD) motivates quantification of the optical interactions forming the basis for this detection mechanism. MOD is used to measure the intensity of polarized light transmitted through a sample of hemozoin suspended in phosphate-buffered saline, subject to a magnetic field ($\vec{B}$) that can be turned on and off. According to Beer’s law, ratios of transmitted light with $\vec{B}$ on and off as a function of hemozoin concentration are related to change in cross-sectional absorption $\Delta\sigma=\sigma_{B\ \textrm{on}}-\sigma_{B\ \textrm{off}}$. We tested several hemozoin concentrations, linearly fit intensity ratio versus concentration data, and accounted for thermal effects using a basis transformation to find $\sigma_{\parallel}-\sigma_{\perp}=1.56\pm0.43 \textrm{cm}^3$ where $\sigma_{\parallel}$ $(\sigma_{\perp})$ corresponds to polarization parallel (perpendicular) to $\vec{B}$. This result is comparable to other published work, and the quantification of $\sigma_{\parallel}-\sigma_{\perp}$ informs our understanding of the magneto-optical properties of hemozoin, which advances malaria detection. [Preview Abstract] |
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A02.00025: Investigating Heterogeneity within Sickle Cell Disease Using Deep Learning Niksa Praljak, Shamreen Iram, Gundeep Singh, Alilis Hill, Utku Goreke, Umut Gurkan, Michael Hinczewski SCD is an inherited red blood cell (RBC) disorder associated with abnormal hemoglobin S (HbS). Long fibers are formed by intracellular HbS molecules. These fibers lead to damaged cell membranes. In addition, the HbS polymerization increases the RBC-endothelial adhesion within vascular tubules by damaging the RBC membrane. A key component to SCD morbidity is periodic recurrence of painful vaso-occlusion and blood flow alteration. The lack of diagnosis and early treatment can be better tackled with access to economically and operationally light point of care (POC) screening and monitoring tools. Creative POC technologies could offer cost-efficient and reliable screening strategies for SCD. Our collaborators at CWRU School of Engineering have designed a sickle cell disease monitoring platform (SCD Biochip) [Alapan et al. Translational Research, 173, 74-91, (2016)] which runs clinical whole blood samples through protein functionalized microchannels in experiments designed to mimic conditions in microvasculature. We propose a workflow that will attempt to investigate the heterogeneity within the biophysical properties and descriptions that link to pathological markers by implementing artificial intelligence alongside the SCD Biochip under various dynamics. [Preview Abstract] |
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A02.00026: Solid angle subtended by simple planar shapes along fixed axes Bharath Thotakura We investigated the solid angle subtended by various planar shapes when viewed from a fixed height along either an axis of symmetry or an offset axis. In particular, we were able to find analytic formulas for the solid angle of a circle, triangle, and ellipse. We also show the generalization of the solid angle of a triangle into the solid angle of an arbitrary regular polygon. The calculation of the solid angle has wide ranging applications in physics, and as examples, we show the relationship between the solid angle and the magnetic field of a planar current carrying loop of wire, and Gauss's Law for electric flux. [Preview Abstract] |
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A02.00027: Reaction-diffusion around concave, spiral, fractal \& soft obstacles Yang Yu, Niklas Manz, John Lindner We study the behavior of wavefronts colliding with different concave fractals, spirals, and Perlin noise simulations in two-dimensional channels using finite-difference numerical integration based on Tyson-Fife reduction of the Oregonator model of the Belousov-Zhabotinsky reaction. We study the influence of obstacles’ shapes on the wavefronts’ behaviors by plotting wavefront time versus left most point of the wave and delay versus time with obstacles on different angles and generations. We find that wavefronts behave the same when it goes through symmetric obstacles (for example, Hilbert curve and Sierpinski carpet). Due to the plot of vanish time versus generation of the obstacles, we predict that the vanish time will go to infinity. By changing the diffusion equation, we make the diffusion constant a function of space and the reaction constant a function of the light sensitive parameter $\phi$. We build animations that a piece of wave is trapped in the obstacle, which generates periodic motion. [Preview Abstract] |
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A02.00028: Study on the Themo-chemical Effects of the Nano Scaled Cosmetic Molecules Using Computational Analysis Emily W. Chung, Amanda Kyung Components in cosmetics or sunscreens can be degraded in the existence of UV light and the photodegradation causes a loss of UV protection irritating skin or damaging DNA in cells. In this research, computational methods employing quantum chemistry were used to model various components in sunscreens. The safety of the molecules were checked by assessing thermodynamic stability, reactivity and polarization. Thermodynamic stability was measured through the optimized energy and the reactivity and conductivity were measured through the dipole moments to calculate the level of activity the molecule could have with other nearby molecules. Lastly, electrostatic potential maps were also used to visualize the polarization and assess the reactivity level of each molecule. Molecules in the sunscreen with lower optimization energies were predicted to be more thermodynamically stable than those with higher optimization energies. Molecules with higher dipole moment were predicted to be more active than those with lower dipole moment. Also, molecules with more colorful electrostatic potential map was predicted to be more active than those with less colorful electrostatic potential map. [Preview Abstract] |
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A02.00029: LISE Simulations and Analysis Used to Adjust Setup for the Mass Measurement of 46S Miles Barber, Alfredo Estrade We performed ion beam simulations with the code LISE to optimize the experimental setup for a mass measurement of the neutron-rich isotope 46S. For this endeavor two main questions were the focus. 1. What wedge thickness could we add to the beamline in order to give us both beam purity (less contaminants) and low dispersion of fragments at the first timing detector? 2. How valuable is measuring the position of fragments at certain points in the beamline and can it help improve the time-of-flight resolution? Answering these two questions will bring us much closer to the goal of measuring 46S with less than 100 KeV/c\textasciicircum 2 uncertainty. [Preview Abstract] |
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A02.00030: Fast Quantum Control of Trapped $^{87}$Rb Bose-Einstein Condensates Denuwan Vithanage, E. Carlo Samson We present numerical simulations to manipulate Bose-Einstein condensates (BECs) in a fast rate, while maintaining the coherence properties of its initial quantum state. Specifically, the objective is to quickly transport a trapped BEC along a specific distance in a short amount of time using painted potentials. We are using shortcuts-to-adiabaticity (STA) to keep high fidelity while high-speed transport occurs. 2D simulations of BEC transport are achieved by numerically solving the Gross-Pitaevskii equation (GPE) using a split-step Fourier method. With these simulations, we compared different spatial displacements that a BEC can travel while keeping high quantum fidelity using experimentally feasible parameters. [Preview Abstract] |
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A02.00031: Deterministic Routing of Single Photons in Multi-emitter Chiral Waveguide QED Bibandhan Poudyal, Nathan Kravitz, Imran Mirza On-demand single-photon generation and propagation are one of the key requirements in performing several quantum information processing protocols. Gonzalez et al. have recently proposed deterministic routings of few photons in double-waveguide quantum electrodynamics (QED) utilizing preferential photon emissions into waveguide modes (chirality). Extending their work, in this study, we ask the question that how the performance of such a single-photon quantum router involving chiral waveguides alters in the many-emitter regime. In particular, we ask the question that can we gain better control of routing phenomena in the presence of many-emitters? With the recent developments in scalability of circuit QED platforms, we believe that our work can find applications in near future quantum networking and quantum computing experiments. [Preview Abstract] |
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A02.00032: Angular Velocity Measurements of Rotating Plasma Rings William Theisen, Matt Sibila The rotational motion of a strongly-coupled unmagnetized dusty plasma rings is studied. The particles move in the ring shaped potential that is formed using a variable aperture with a center post. Particle position data is analyzed and the angular velocity of the particles is calculated. The rotation rate of the ring depends on the number of particles, the variability of the inter-particle spacing, and the pressure. [Preview Abstract] |
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A02.00033: ABSTRACT WITHDRAWN |
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A02.00034: Stellar and Gas kinematics of the S0 galaxy NGC 3585 Bradlee McIntosh, Jason Pinkney We present new stellar kinematics for the nearby (18 Mpc) lenticular (S0) galaxy NGC 3585. This is one of a larger sample of galaxies observed with STIS (the Space Telescope Imaging Spectrograph)and the Magellan 6.5-m telescopes with the goal of measuring the masses of the nuclear black holes (BH) and seeing how they correlate with galaxy properties (i.e., the demographics of supermassive BH). We compare our kinematics to other published kinematics already used to measure the mass of the supermassive black hole in this galaxy. HST images of this galaxy reveal an organized dust disk at its center. Such dust disks usually coincide with gas disks that can also be used to measure the central black hole's mass if the gas produces line emission. Unfortunately, we do not detect emission lines ([OIII] and H$\beta$) and so we conclude that the gas is not strongly ionized. Finally, we measure the effective velocity dispersion $\sigma_e$ needed to plot NGC 3585 on the $M_{BH}- \sigma_e$ relation governing supermassive black holes. [Preview Abstract] |
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A02.00035: Measurements of Atmospheric Physics with a Weather Balloon Darby Thomason, Przemyslaw Piotrowski, Tyler Yuzwalk, Ruth Willet, Mckendry Evans, Timothy Stiles, Ronald E. Kumon The Kettering University Physics Club built, launched, and recovered a weather balloon, which was tracked in real-time using a radio transmitter. The balloon traveled 45 km from the launch location and reached an altitude of 35 km at its peak. The flight computer took measurements of atmospheric pressure, temperature, and speed as a function of latitude, longitude, and altitude. A 360-degree camera was also used to acquire continuous video during the 3.75 hour flight and resulted in some stratospheric images of southeastern Michigan distinctly showing the curvature of the Earth. The measured profiles of temperature as a function of altitude were approximately consistent with the model of the U.S. Standard Atmosphere. [Preview Abstract] |
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A02.00036: Study on the Organic Solar Cells to Improve Electrical Efficiency Using Physical and Computational Analysis Jaehong Min, Richard Kyung Researchers have been searching for an eco-friendly and sustainable energy source that can replace fossil fuels to alleviate the future energy crisis. Renewable solar cells have been identified as a potential solution for manufacturing miniaturized low-cost photovoltaic cell. In this research, organic materials such as fullerene analogs as electron acceptors were studied using computational and physical methods to increase the electric fields in the OSC (Organic Solar Cell) unit. Electric and thermodynamic properties of isotropic thin organic materials, such as optimized energy (kJ/mol) and dipole moment (debye), were calculated using a computational program. Furthermore, electrostatic potential maps were found and analyzed in the assessment of activity and stability of the OSCs for sustainable solar cell development. Specifically, this research focuses on increasing electric properties of solar batteries using different types of organic nanoparticles. To increase the stability of OSCs to store more energy efficiently, various combinations of C60 fullerene derivatives were tested to differ the structure of functional groups. [Preview Abstract] |
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A02.00037: Synthesis of Gold Nanoparticles Using Microfluidic Mixers Benjamin Bosela, Alexa Roberts, Chandra Kothapalli, Petru Fodor Microfluidic devices can be used to perform multiple chemical reactions on a small scale. Some benefits of microfluidic reactions over batch reactions include greater portability, more accurate data, quicker reactions, precise verification of temperature, and more cost-effective experiments. Microfluidic mixers can be used to synthesize gold nanoparticles by mixing gold chloride and sodium citrate. Previously, the optimal set of mixing conditions was concluded for a reverse staggered-herringbone mixer. Currently, four different mixers were put in place and tested using the same conditions for each mixer. After collecting samples from the outlet tubes of the mixers, sample preparation was performed and the samples were analyzed using SEM. Particle sizes were measured and quantified during imaging. Particle size distributions were constructed and results for each mixer were compared to comprehend the effectiveness and ability of the different devices. Future work will entail testing different flow rates, temperatures, and pH levels to see how they effect particle sizes in these four mixers [Preview Abstract] |
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A02.00038: Beam Energy Dependence of Distinguishable Particle Correlations in Heavy-Ion Collisions at STAR Launa Di Carlo, Amelia Doetsch, Bekele Erko, Brian Hanley, William Llope Heavy-ion collisions allow one to study the properties of the Quark Gluon Plasma (QGP), a hot and dense strongly-interacting system of deconfined quarks and gluons. These hot systems are produced at the Relativistic Heavy Ion Collider (RHIC) and measured by the Solenoidal Tracker at RHIC (STAR) detector. The STAR detector measures the momentum and identifies the particles produced in each collision. A measurement of the correlations between pairs of particles in each event provides the information needed to understand the collision dynamics. A specific multiplicity-weighted correlation function, called the Balance Function (BF), provides additional information on the ``flow" of conserved quantities such as the electric charge and baryon number as a function of kinetic observables such as the rapidity and azimuthal angle. In this analysis, two-particle correlators, called ``$R_2$", and balance functions have been measured for identified charged particle pairs (protons, kaons, and pions). Data from STAR for Au+Au collisions at eight different beam energies ranging from $\sqrt{s_{NN}}$ = 7.7 GeV to 200 GeV will be analyzed. We report on the latest results and future plans. [Preview Abstract] |
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A02.00039: Study on the Corrosion Protection of Paint Coating with Eco-Friendly Inhibitors Megan Cui, Richard Kyung Computational modeling and simulations are efficient methods for understanding corrosion and corrosion protection. Based on the physical, chemical and thermodynamic properties of materials, making predictions of corrosion was presented in this paper. To inhibit material corrosion such as metallic or paint corrosion, this paper have focused on finding either naturally-made or artificially modified compounds that can prevent these oxidation and corrosion. Due to its anti-corrosion performance, phytoncide molecules have been found to impact the growth of rustic or oxidized molecules. Since the anticorrosion and antimicrobial potency and range of phytoncides vary greatly among agents, activity of various antioxidant components of extracts were studied. The reactivity and conductivity have been measured through the dipole moments to calculate the activity level the molecule could have with other nearby molecules. Also, electrostatic potential maps were utilized to visualize the polarization and assess the reactivity level of each molecule. The benefit of modeling corrosion using the computational simulations is that the design and optimization can be done quickly and at a lower cost, which also lowers the risk of expensive redesigns occurred in the laboratory experiment. [Preview Abstract] |
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A02.00040: Study on the Activity of Cadmium and its Compounds as Air Pollutants Jae Woo Kuh, Jaemin Choung, Andrew Kyung Heavy metals such as manganese and cadmium are ubiquitous air pollutant which are increasing in the environment. Air pollutants are responsible for genotoxic events related to many disease processes, including carcinogenesis, that are often attributed to poorly-detected air pollutants. Also, several non-standard forms of Parkinsonism may be associated with occupational exposure to cadmium, manganese and other heavy metals in air pollutants. The toxicity concerns regarding cadmium are limited since the exposure to the cadmium is known due to ingestion primarily. However, a recent research shows that exposure to the air is far more potent since the biologic effects of this highly mobile metal was identified. In this paper, the activity of cadmium with different compounds was evaluated by physical and computational chemical simulation which measures the optimized geometries and chemical properties of the modeled structures by using theoretical values and considering the molecules’ atomic properties. [Preview Abstract] |
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