Astrophysics and Astronomy Commons^™

Underwater Adhesive Using Solid–Liquid Polymer Mixes, Alin Cristian Chipara, T. Tsafack, P. S. Owuor, J. Yeon, C. E. Junkermeier, A. C. T. Van Duin, S. Bhowmick, S. A. S. Asif, S. Radhakrishnan, Mircea Chipara

Physics & Astronomy Faculty Publications

Instantaneous adhesion between different materials is a requirement for several applications ranging from electronics to biomedicine. Approaches such as surface patterning, chemical cross-linking, surface modification, and chemical synthesis have been adopted to generate temporary adhesion between various materials and surfaces. Because of the lack of curing times, temporary adhesives are instantaneous, a useful property for specific applications that need quick bonding. However, to this day, temporary adhesives have been mainly demonstrated under dry conditions and do not work well in submerged or humid environments. Furthermore, most rely on chemical bonds resulting from strong interactions with the substrate such as acrylate …

Photoproduction Of K+ K- Meson Pairs On The Proton, S. Lombardo, M. Battaglieri, A. Celentano, A. D'Angelo, R. De Vita, A. Filippi, D. I. Glazier, M. Khachatryan, A. Klein, Y. Prok, The Clas Collaboration

Physics Faculty Publications

The exclusive reaction γp → pK⁺K⁻ was studied in the photon energy range 3.0–3.8 GeV and momentum transfer range 0.6 < −t< 1.3 GeV². Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. In this kinematic range the integrated luminosity was approximately 20 pb⁻¹. The reaction was isolated by detecting the K⁺ and the proton in CLAS, and reconstructing the K⁻ via the missing-mass technique. Moments of the dikaon decay angular distributions were extracted from the experimental data. Besides the dominant contribution of the ϕ meson in the P wave, …

Dark Energy Survey Year 1 Results: Cosmological Constraints From Galaxy Clustering And Weak Lensing, T. M. C. Abbott, F. B. Abdalla, A. Alarcon, J. Aleksic, S. Allam, S. Allen, A. Amara, J. Annis, J. Asorey, S. Avila, D. Bacon, E. Balbinot, M. Banerji, N. Banik, Wayne Barkhouse

Physics Faculty Publications

We present cosmological results from a combined analysis of galaxy clustering and weak gravitational lensing, using 1321  deg2 of griz imaging data from the first year of the Dark Energy Survey (DES Y1). We combine three two-point functions: (i) the cosmic shear correlation function of 26 million source galaxies in four redshift bins, (ii) the galaxy angular autocorrelation function of 650,000 luminous red galaxies in five redshift bins, and (iii) the galaxy-shear cross-correlation of luminous red galaxy positions and source galaxy shears. To demonstrate the robustness of these results, we use independent pairs of galaxy shape, photometric-redshift estimation and validation, …

Nitrogen-To-Oxygen Abundance Ratio Variation In Quiescent Galaxies, Renbin Yan

Physics and Astronomy Faculty Publications

For the first time, we establish a gas-phase abundance pattern calibration for quiescent galaxies using optical emission lines. Quiescent galaxies have warm ionized gas showing line ratios similar to low-ionization nuclear emission line regions. The ionization mechanism for the gas is still an unsettled puzzle. Despite the uncertainty in the ionization mechanism, we argue that we can still infer certain gas-phase abundance pattern from first principles. We show that the relative trend in N/O abundance can still be reliably measured based on [N II] λλ6548,6583/[O II] λλ3726,3729 and a direct measurement of the electron temperature. We construct a composite direct …

Suppression Of Dielectronic Recombination Due To Finite Density Effects. Ii. Analytical Refinement And Application To Density-Dependent Ionization Balances And Agn Broad-Line Emission, D. Nikolić, T. W. Gorczyca, K. T. Korista, Marios Chatzikos, Gary J. Ferland, Francisco Guzmán, P. A. M. Van Hoof, R. J. R. Williams, N. R. Badnell

Physics and Astronomy Faculty Publications

We present improved fits to our treatment of suppression of dielectronic recombination at intermediate densities. At low densities, most recombined excited states eventually decay to the ground state, and therefore the total dielectronic recombination rate to all levels is preserved. At intermediate densities, on the other hand, collisions can lead to ionization of higher-lying excited states, thereby suppressing the dielectronic recombination rate. The improved suppression factors presented here, although highly approximate, allow summed recombination rate coefficients to be used to intermediate densities. There have been several technical improvements to our previously presented fits. For H- through B-like ions the activation …

A Search For Possible Long Range Spin Dependent Interactions Of The Neutron From Exotic Vector Boson Exchange, C. Haddock, J. Amadio, E. Anderson, L. Barrón-Palos, B. Crawford, Christopher B. Crawford, D. Esposito, W. Fox, I. Francis, J. Fry, H. Gardiner, A. Holley, K. Korsak, J. Lieffers, S. Magers, M. Maldonado-Velázquez, D. Mayorov, J. S. Nico, T. Okudaira, C. Paudel, S. Santra, M. Sarsour, H. M. Shimizu, W. M. Snow, Aaron P. Sprow, K. Steffen, H. E. Swanson, F. Tovesson, J. Vanderwerp, P. A. Yergeau

Physics and Astronomy Faculty Publications

We present a search for possible spin dependent interactions of the neutron with matter through exchange of spin 1 bosons with axial vector couplings as envisioned in possible extensions of the Standard Model. This was sought using a slow neutron polarimeter that passed transversely polarized slow neutrons by unpolarized slabs of material arranged so that interactions would tilt the plane of polarization and develop a component along the neutron momentum. The result for the rotation angle, ϕ′=[2.8±4.6(stat.)±4.0(sys.)]×10⁻⁵ rad/m is consistent with zero. This result improves the upper bounds on the neutron-matter coupling g²_{A …}

Correlation Measurements Between Flow Harmonics In Au + Au Collisions At Rhic, J. Adam, L. Adamczyk, J. R. Adams, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, F. Atetalla, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. J. Bassill, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

Flow harmonics (v_n) in the Fourier expansion of the azimuthal distribution of particles are widely used to quantify the anisotropy in particle emission in high-energy heavy-ion collisions. The symmetric cumulants, SC(m,n), are used to measure the correlations between different orders of flow harmonics. These correlations are used to constrain the initial conditions and the transport properties of the medium in theoretical models. In this Letter, we present the first measurements of the four-particle symmetric cumulants in Au+Au collisions at √s_NN=39 and 200 GeV from data collected by the …

Shocks Or Photoionization: Direct Temperature Measurements Of The Low-Ionization Gas In Quiescent Galaxies, Renbin Yan

Physics and Astronomy Faculty Publications

The ionization mechanism of the low-ionization gas in quiescent red-sequence galaxies has been a long-standing puzzle. Direct temperature measurements would put strong constraints on this issue. We carefully selected a sample of quiescent red-sequence galaxies from Sloan Digital Sky Survey. We bin them into three bins with different [N II]/H α and [N II]/[O II] ratios, and we measure the temperature-sensitive [O III] λ4363, [N II] λ5755, [S II] λλ4068, 4076, and [O II] λλ7320, 7330 lines in the stacked spectra. The [S II] doublet ratios indicate the line-emitting gas is in the low-density regime (∼10–200 cm⁻³). We …

Fluctuating Hydrodynamics Of Reactive Liquid Mixtures, Changho Kim, Andy. Nonaka, John Bell, Alejandro Garcia, Aleksandar Donev

Faculty Publications

Fluctuating hydrodynamics (FHD) provides a framework for modeling microscopic fluctuations in a manner consistent with statistical mechanics and nonequilibrium thermodynamics. This paper presents an FHD formulation for isothermal reactive incompressible liquid mixtures with stochastic chemistry. Fluctuating multispecies mass diffusion is formulated using a Maxwell–Stefan description without assuming a dilute solution, and momentum dynamics is described by a stochastic Navier–Stokes equation for the fluid velocity. We consider a thermodynamically consistent generalization for the law of mass action for non-dilute mixtures and use it in the chemical master equation (CME) to model reactions as a Poisson process. The FHD approach provides remarkable …

High Dynamic Range Optical Devices And Applications., Elijah Robert Jensen

Electronic Theses and Dissertations

Much of what we know about fundamental physical law and the universe derives from observations and measurements using optical methods. The passive use of the electromagnetic spectrum can be the best way of studying physical phenomenon in general with minimal disturbance of the system in the process. While for many applications ambient visible light is sufficient, light outside of the visible range may convey more information. The signals of interest are also often a small fraction of the background, and their changes occur on time scales so quickly that they are visually imperceptible. This thesis reports techniques and technologies developed …

First Measurement Of Ξ− Polarization In Photoproduction, J. Bono, L. Guo, K. P. Adhikari, M. J. Amaryan, G. Charles, G. Gavalian, M. Khachatryan, A. Klein, Y. Prok, J. Zhang, Z. W. Zhao

Physics Faculty Publications

Despite decades of studies of the photoproduction of hyperons, both their production mechanisms and their spectra of excited states are still largely unknown. While the parity-violating weak decay of hyperons offers a means of measuring their polarization, which could help discern their production mechanisms and identify their excitation spectra, no such study has been possible for doubly strange baryons in photoproduction, due to low production cross sections. However, by making use of the reaction γ p → K⁺K⁺Ξ−, we have measured, for the first time, the induced polarization, P, and the transferred polarization from circularly polarized …

Effect Of Chemistry On Electrodynamics In The Martian Dynamo Region, Morgan M. Matheny

Doctoral Dissertations and Master's Theses

Electromagnetic interactions between Mars remnant crustal magnetic fields and solar and planetary ions lead to time and space variations of the ionosphere. In this work, we continue the investigations started by Riousset et al. [2013] and address the effect of chemistry on ion populations in the dynamo region, where ion dynamics are driven by collisions while electrons are still mostly magnetized. We adopt a mesoscale model to simulate dynamics of electrons and ions in the upper atmosphere (100–400 km). Our approach focuses on numerical studies using the Martian Multifluid Magnetohy drodynamic (MF-MHD) Model (M4). The dynamo is a region which …

Cause Of Cambrian Explosion - Terrestrial Or Cosmic?, Edward J. Steele, Shirwan Al-Mufti, Kenneth A. Augustyn, Rohana Chandrajith, John P. Coghlan, S. G. Coulson, Et. Al.

Michigan Tech Publications, Part 1

We review the salient evidence consistent with or predicted by the Hoyle-Wickramasinghe (H-W) thesis of Cometary (Cosmic) Biology. Much of this physical and biological evidence is multifactorial. One particular focus are the recent studies which date the emergence of the complex retroviruses of vertebrate lines at or just before the Cambrian Explosion of ∼500 Ma. Such viruses are known to be plausibly associated with major evolutionary genomic processes. We believe this coincidence is not fortuitous but is consistent with a key prediction of H-W theory whereby major extinction-diversification evolutionary boundaries coincide with virus-bearing cometary-bolide bombardment events. A second focus is …

Space-Time In The Syk Model, Sumit R. Das, Aminik Ghosh, Antal Jevicki, Kenta Suzuki

Physics and Astronomy Faculty Publications

We consider the question of identifying the bulk space-time of the SYK model. Focusing on the signature of emergent space-time of the (Euclidean) model, we explain the need for non-local (Radon-type) transformations on external legs of n-point Green’s functions. This results in a dual theory with Euclidean AdS signature with additional legfactors. We speculate that these factors incorporate the coupling of additional bulk states similar to the discrete states of 2d string theory.

Radon Measurement For Neutrinoless Double Beta Decay, Xavier Carlos Quintana

Physics & Astronomy ETDs

This thesis details the design and operation of a high-sensitivity radon detector for use in background radiation characterization and mitigation for the MAJORANA DEMONSTRATOR Neutrinoless Double Beta Decay Experiment and Large Enriched Germanium Experiment for Neutrinoless Double Beta Decay (LEGEND) Collaboration. Understanding and mitigating background radiation is especially important in searches for very rare nuclear processes, which utilize sensitive detectors. One such rare process is the yet-to-be-observed neutrinoless double beta decay. Observation of this process would imply that the neutrino is its own antiparticle, called a Majorana particle, violate lepton number, and provide experimental constraints on the masses and mixing …

Gamma-Ray Burst Classification: New Insights From Mining Pulse Data, Stanley Mcafee, Jon Hakkila

Journal of the South Carolina Academy of Science

Despite being the most energetic electromagnetic explosions in the universe, gamma-ray bursts (GRBs) are still poorly understood. The literature recognizes two potentially different types of GRB progenitors, although statistical data suggest the existence of three GRB classes. Reliable inference of GRB physics depends on the identification of appropriate classification attributes, as well as on the statistical classification techniques used. It has recently been shown that pulses are the basic unit of GRB emission. We use new data describing GRB pulse characteristics, in conjunction with data mining tools, to provide a more reliable gamma-ray burst classification system and place additional constraints …

Path Integral Complexity For Perturbed Cfts, Arpan Bhattacharyya, Pawal Caputa, Sumit R. Das, Nilay Kundu, Masamichi Miyaji, Tadashi Takayanagi

Physics and Astronomy Faculty Publications

In this work, we formulate a path-integral optimization for two dimensional conformal field theories perturbed by relevant operators. We present several evidences how this optimization mechanism works, based on calculations in free field theories as well as general arguments of RG flows in field theories. Our optimization is performed by minimizing the path-integral complexity functional that depends on the metric and also on the relevant couplings. Then, we compute the optimal metric perturbatively and find that it agrees with the time slice of the hyperbolic metric perturbed by a scalar field in the AdS/CFT correspondence. Last but not the least, …

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.

Characterization Of Eight Potentially Hazardous Near Earth Asteroids: Rotation Period Analysis And Structure Modeling Via Light Curve Inversion Techniques, Stacy Jo Hicks

Masters Theses & Specialist Projects

The term “homeland security”, seems to have become synonymous with terrorism in the minds of the general public. However, there are other threats to the security of the United States homeland that can be just as, if not more, devastating than terrorism. Included among these other threats is the potential of an asteroid collision with Earth. Historically, asteroid impact events have been responsible for the devastation of our planet and many of the mass extinction events encountered throughout the geologic record. Knowledge of physical parameters such as structure and rotational dynamics of the asteroid are critical parameters in developing interception …

Molpop-Cep: An Exact, Fast Code For Multi-Level Systems, Andrés Asensio Ramos, Moshe Elitzur

Physics and Astronomy Faculty Publications

We present MOLPOP-CEP, a universal line transfer code that allows the exact calculation of multi-level line emission from a slab with variable physical conditions for any arbitrary atom or molecule for which atomic data exist. The code includes error control to achieve any desired level of accuracy, providing full confidence in its results. Publicly available, MOLPOP-CEP employs our recently developed coupled escape probability (CEP) technique, whose performance exceeds other exact methods by orders of magnitude. The program also offers the option of an approximate solution with different variants of the familiar escape probability method. As an illustration of the MOLPOP-CEP …

Finite-Volume Effects Due To Spatially Nonlocal Operators, Raúl A. Briceño, Juan V. Guerrero, Maxwell T. Hansen, Christopher J. Monahan

Physics Faculty Publications

Spatially nonlocal matrix elements are useful lattice-QCD observables in a variety of contexts, for example in determining hadron structure. To quote credible estimates of the systematic uncertainties in these calculations, one must understand, among other things, the size of the finite-volume effects when such matrix elements are extracted from numerical lattice calculations. In this work, we estimate finite- volume effects for matrix elements of nonlocal operators, composed of two currents displaced in a spatial direction by a distance ξ. We find that the finite-volume corrections depend on the details of the matrix element. If the external state is the lightest …

One-Loop Evolution Of Parton Pseudo-Distribution Functions On The Lattice, Anatoly Radyushkin

Physics Faculty Publications

We incorporate recent calculations of one-loop corrections for the reduced Ioffe-time pseudo-distribution m(v, z(3)(2) thorn to extend the leading-logarithm analysis of lattice data obtained by Orginos et al. We observe that the one-loop corrections contain a large term reflecting the fact that effective distances involved in the most important diagrams are much smaller than the nominal distance z(3). The large correction in this case may be absorbed into the evolution term, and the perturbative expansion used for extraction of parton densities at the μ ≈ 2 GeV scale is under control. The extracted parton distribution is rather close to global …

Broadband Measurement And Reduction Of Quantum Radiation Pressure Noise In The Audio Band, Jonathan Daniel Cripe

LSU Doctoral Dissertations

One hundred years after Albert Einstein predicted the existence of gravitational waves in his general theory of relativity, the Laser Interferometer Gravitational-Wave Observatory (LIGO) made the first direct detection of gravitational waves. Since the first detection of gravitational waves from a binary black hole merger, LIGO has gone on to detect gravitational waves from multiple binary black hole mergers, and more recently from a binary neutron star merger in collaboration with telescopes around the world. The detection of gravitational waves has opened a new window to the universe and has launched the era of gravitational wave astronomy.

With the first …

Neutrino Flavor Conversions In Dense Media, Lei Ma

Physics & Astronomy ETDs

Neutrinos are abundantly produced in astrophysical environments such as core-collapse supernovae and binary neutron star mergers. Neutrino flavor conversions in the dense media play important roles in the physical and chemical evolutions of the environments. In this dissertation, I study two mechanisms through which neutrinos may change their flavors.

In the first mechanism, neutrinos can experience flavor conversions through interactions with oscillatory perturbations in matter distributions. I show that this mechanism can be understood intuitively as Rabi oscillations. I also derive criteria which can be used to determine whether such parametric resonances exist in a given environment.

In the second …

Low Resolution Hi Imaging Of The Shield Galaxies, Masao L. Miazzo

Macalester Journal of Physics and Astronomy

We present low-resolution Karl G. Jansky Very Large Array D-configuration HI spectral line observations of 32 previously unobserved local-volume low-mass dwarf galaxies in the Survey of HI in Extremely Low-mass Dwarfs (SHIELD). SHIELD was designed to probe the physical characteristics of the objects that inhabit the faint end of the HI mass function as populated by the ALFALFA blind HI extragalactic survey. These low angular-resolution images localize the HI-gas and provide the first glimpse of the neutral interstellar medium in these sources. We quantify the total HI mass of each system, and, using SDSS imaging, we compare the HI and …

Modeling Recombination In Solar Cells, Paul Chery

Macalester Journal of Physics and Astronomy

Solar cells are a competitive alternative to nonrenewable energy sources such as fossil fuels. However, the efficiency of these devices is limited by photogenerated carrier recombination. We use a finite difference numerical model to study recombination phenomena in the absorber layer of solar cells including alternate recombination models and the effects of spatial distribution of recombination centers. We compare the effect of using the constant lifetime approximation for recombination to the full Shockley-Read-Hall expression in Silicon solar cells and find that the constant lifetime approximation holds for high defect densities but not for high photon flux densities. Finally, we simulate …

Young Blue Straggler Stars In The Galactic Field, Gemunu Ekanayake, Ronald Wilhelm

Physics and Astronomy Faculty Publications

In this study, we present an analysis of a sample of field blue straggler (BS) stars that show high ultra violet emission in their spectral energy distributions (SEDs): indication of a hot white dwarf (WD) companion to BS. Using photometry available in the Sloan Digital Sky Survey (SDSS) and Galaxy Evolution Explorer (GALEX) surveys, we identified 80 stars with ultraviolet (UV) excess. To determine the parameter distributions (mass, temperature, and age) of the WD companions, we developed a fitting routine that could fit binary model SEDs to the observed SED. Results from this fit indicate the need for a hot …

How Middle Level Science Teachers Visualize And Translate Motion, Scale, And Geometric Space Of The Earth-Moon-Sun System With Their Students, Jennifer Wilhelm, Merryn Cole, Cheryl Cohen, Rebecca Lindell

Science, Technology, Engineering, and Mathematics (STEM) Education Faculty Publications

[This paper is part of the Focused Collection on Astronomy Education Research.] We examined teachers’ spatial-scientific reasoning and the alternative conceptions they held regarding Earth-space content. While participating in a professional development (PD) workshop, teachers engaged in an integrated mathematics and science project-based unit designed to foster spatial reasoning and improve lunar-related conceptual understanding. The Purdue Spatial Visualization Test-Rotation (PSVT-Rot) and the Lunar Phases Concept Inventory (LPCI) were used to assess understanding. We found the teachers held similar alternative conceptions as their students. Moreover, we discovered that teachers had limited understanding of the Earth-Moon-Sun scale, motions, and geometric configurations. To …

Controlling The Hydrophilicity And Cohesion During Deposition Of Highly Oriented Type I Collagen Films: An Approach For Biomedical Applications, Karina Ambrock, Bernd Grohe, Silvia Mittler

Physics and Astronomy Publications

Using the Langmuir-Blodgett (LB) technology we have pioneered a straightforward and low-cost approach to fabricate highly oriented collagen in thin film format (thickness: ~20 nm, surface areas: 2.5 x ~6.0 cm). An important factor for the use of these films is their cohesion under various conditions. Film formation was studied by coating hydrophilic or hydrophobic glass substrates. The fresh or aged (2 ½ years, -18°C.) collagen solutions used for this purpose either contained collagen network-stabilizing agents (n-propanol or phosphate ions) or were prepared without these stabilizers. Film formation on the air/water interface was analyzed by pressure-area isotherms. Maximum surface pressures …

Anatomy Of The Ρ Resonance From Lattice Qcd At The Physical Point, Wei Sun, Andrei Alexandru, Ying Chen, Terrence Draper, Zhaofeng Liu, Yi-Bo Yang, Χqcd Collaboration

Physics and Astronomy Faculty Publications

We propose a strategy to access the qq component of the ρ resonance in lattice QCD.

For the remainder of the abstract, please download this article or visit https://doi.org/10.1088/1674-1137/42/6/063102.