Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

32,245 Full-Text Articles 49,265 Authors 8,161,933 Downloads 269 Institutions

All Articles in Physics

Faceted Search

32,245 full-text articles. Page 6 of 894.

College Of Natural Sciences Newsletter, March 2021, College Of Natural Sciences 2021 South Dakota State University

College Of Natural Sciences Newsletter, March 2021, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volume 2. Issue 3

Contents:

Page 1 Dean's Message
Page 2-3 Awards and Recognition
Page 4 Student Club Spotlight: MICROBIOLOGY CLUB
Page 5 Research Spotlight: Dr. Chakravarty
Page 6 Open PRAIRIE Data; Grants Awarded in CNS; Research Collquia
Page 7 A Busy Month in Review; Media Coverage of the College


Potential Environmental Effects Of Deepwater Floating Offshore Wind Energy Facilities, Hayley Farr, Benjamin Ruttenberg, Ryan K. Walter, Yi-Hui Wang, Crow White 2021 California Polytechnic State University, San Luis Obispo

Potential Environmental Effects Of Deepwater Floating Offshore Wind Energy Facilities, Hayley Farr, Benjamin Ruttenberg, Ryan K. Walter, Yi-Hui Wang, Crow White

Physics

Over the last few decades, the offshore wind energy industry has expanded its scope from turbines mounted on foundations driven into the seafloor and standing in less than 60 m of water, to floating turbines moored in 120 m of water, to prospecting the development of floating turbines moored in ~1,000 m of water. Since there are few prototype turbines and mooring systems of these deepwater, floating offshore wind energy facilities (OWFs) currently deployed, their effects on the marine environment are speculative. Using the available scientific literature concerning appropriate analogs, including fixed-bottom OWFs, land-based wind energy facilities, wave and ...


Statistics Of Velocity Fluctuations In A Homogeneous Liquid Fluidized Bed, Elise Alméras, Frédéric Risso, Olivier Masbernat, Rodney O. Fox 2021 Université de Toulouse

Statistics Of Velocity Fluctuations In A Homogeneous Liquid Fluidized Bed, Elise Alméras, Frédéric Risso, Olivier Masbernat, Rodney O. Fox

Chemical and Biological Engineering Publications

This work reports an experimental investigation of a liquid-solid fluidized bed involving inertial particles at a large Reynolds number. Owing to optical techniques and index matching, the statistics of the velocity fluctuations of both the particles and the liquid are measured for a wide range of the particle volume fraction αp. The dynamics of the fluctuations suggests that the flow possesses the following three properties: (1) The liquid volume involves a wake region in which vertical fluctuations are negative and an interstitial region where they are positive. (2) The statistics of the horizontal fluctuations are similar to vertical ones, except ...


Investigation Of The Use Of Coincidences Between Fast Neutrons And Gamma Rays For The Detection Of Special Nuclear Materials, Débora M. Trombetta, Bo Cederwall, Kåre Axell 2021 Royal Institute of Technology - KTH

Investigation Of The Use Of Coincidences Between Fast Neutrons And Gamma Rays For The Detection Of Special Nuclear Materials, Débora M. Trombetta, Bo Cederwall, Kåre Axell

International Journal of Nuclear Security

The emergence of new methodologies with promising applications that could impact nuclear security and emergency preparedness detection systems in the near future motivate the development of computational tools that allow the theoretical investigation of the relevant design parameters for such detection systems. Here, we present Monte Carlo simulations using the MCNP6 code to investigate the use of fast neutron-neutron and gamma-neutron coincidences in addition to conventional methods for detection of special nuclear materials (SNM) using inorganic scintillator detectors. The results show fair agreement between MCNP6 and MCNP-PoliMi simulations for neutron-neutron coincidences and that coincident detection of gamma rays and fast ...


Superfluid Swimmers, German Kolmakov, Igor S. Aranson 2021 CUNY New York City College of Technology

Superfluid Swimmers, German Kolmakov, Igor S. Aranson

Publications and Research

The propulsion of living microorganisms ultimately relies on viscous drag for body-fluid interactions. The self-locomotion in superfluids such as 4He is deemed impossible due to the apparent lack of viscous resistance. Here, we investigate the self-propulsion of a Janus (two-face) light-absorbing particle suspended in superfluid helium 4He (He-II). The particle is energized by the heat flux due to the absorption of light from an external source. We show that a quantum mechanical propulsion force originates due to the transformation of the superfluid to a normal fluid on the heated particle face. The theoretical analysis is supported by the ...


Quasinormal Modes And Their Overtones At The Common Horizon In A Binary Black Hole Merger, Pierre Mourier, Xisco Jimenez Forteza, Daniel Pook-Kolb, Dadri Krishnan, Erik Schnetter 2021 Max Planck Inst Gravitat Phys, Albert Einstein Inst, Callinstr 38, D-30167 Hannover, Germany, Leibniz Univ Hannover, D-30167 Hannover, Germany

Quasinormal Modes And Their Overtones At The Common Horizon In A Binary Black Hole Merger, Pierre Mourier, Xisco Jimenez Forteza, Daniel Pook-Kolb, Dadri Krishnan, Erik Schnetter

Faculty Publications

It is expected that all astrophysical black holes in equilibrium are well described by the Kerr solution. Moreover, any black hole far away from equilibrium, such as one initially formed in a compact binary merger or by the collapse of a massive star, will eventually reach a final equilibrium Kerr state. At sufficiently late times in this process of reaching equilibrium, we expect that the black hole is modeled as a perturbation around the final state. The emitted gravitational waves will then be damped sinusoids with frequencies and damping times given by the quasinormal mode spectrum of the final Kerr ...


Anisotropic Superconductivity In The Spin-Vortex Antiferromagnetic Superconductor Cak(Fe0.95ni0.05)(4)As-4, José Benito Llorens, Edwin Herrera, Víctor Barrena, Beilun Wu, Niclas Heinsdorf, Vladislav Borisov, Roser Valentí, William R. Meier, Sergey L. Bud’ko, Paul C. Canfield, Isabel Guillamón, Hermann Suderow 2021 Universidad Autónoma de Madrid

Anisotropic Superconductivity In The Spin-Vortex Antiferromagnetic Superconductor Cak(Fe0.95ni0.05)(4)As-4, José Benito Llorens, Edwin Herrera, Víctor Barrena, Beilun Wu, Niclas Heinsdorf, Vladislav Borisov, Roser Valentí, William R. Meier, Sergey L. Bud’Ko, Paul C. Canfield, Isabel Guillamón, Hermann Suderow

Ames Laboratory Accepted Manuscripts

High critical temperature superconductivity often occurs in systems where an antiferromagnetic order is brought near T=0 K by slightly modifying pressure or doping. CaKFe4As4 is a superconducting, stoichiometric iron-pnictide compound showing optimal superconducting critical temperature with Tc as large as 35 K. Doping with Ni induces a decrease in Tc and the onset of spin-vortex crystal (SVC) antiferromagnetic order, which consists of spins pointing inwards to or outwards from alternating As sites on the diagonals of the in-plane square Fe lattice. Here we study the band structure of CaK(Fe0.95Ni0.05)4As4 (Tc=10 K, TSVC=50 K ...


A Jones Calculus Approach To High-Order Harmonic Generation In Solids, Erin Crites, Shima Gholam-Mirzaei, Zain Khan, Mamta Singh, John E. Beetar 2021 University of Central Florida

A Jones Calculus Approach To High-Order Harmonic Generation In Solids, Erin Crites, Shima Gholam-Mirzaei, Zain Khan, Mamta Singh, John E. Beetar

The Pegasus Review: UCF Undergraduate Research Journal

High-order harmonics from bulk solids were first observed in 2011 by focusing an intense mid-infrared laser through a bulk crystal and detecting the harmonics in a transmission geometry. Due to birefringence and possible nonlinear effects in bulk crystal, the polarization state of the laser can change as it propagates through the crystal in this transmission geometry. This can result in harmonic signal generated with an unknown polarization of light, disrupting the signal. Alternatives to bulk crystal, such as a reflection geometry or thin films, are not always ideal – reflection geometry can introduce nonlinear reflection coefficients, while crystalline thin films can ...


Independently Controlling Stochastic Field Realization Magnitude And Phase Statistics For The Construction Of Novel Partially Coherent Sources, Milo W. Hyde IV 2021 Air Force Institute of Technology

Independently Controlling Stochastic Field Realization Magnitude And Phase Statistics For The Construction Of Novel Partially Coherent Sources, Milo W. Hyde Iv

Faculty Publications

In this paper, we present a method to independently control the field and irradiance statistics of a partially coherent beam. Prior techniques focus on generating optical field realizations whose ensemble-averaged autocorrelation matches a specified second-order field moment known as the cross-spectral density (CSD) function. Since optical field realizations are assumed to obey Gaussian statistics, these methods do not consider the irradiance moments, as they, by the Gaussian moment theorem, are completely determined by the field’s first and second moments. Our work, by including control over the irradiance statistics (in addition to the CSD function), expands existing synthesis approaches and ...


Computation And Data Driven Discovery Of Topological Phononic Materials, Jiangxu Li, Jiaxi Liu, Stanley A. Baronett, Mingfeng Liu, Lei Wang, Ronghan Li, Yun Chen, Dianzhong Li, Qiang Zhu, Xing Qiu Chen 2021 Institute of Metal Research Chinese Academy of Sciences

Computation And Data Driven Discovery Of Topological Phononic Materials, Jiangxu Li, Jiaxi Liu, Stanley A. Baronett, Mingfeng Liu, Lei Wang, Ronghan Li, Yun Chen, Dianzhong Li, Qiang Zhu, Xing Qiu Chen

Physics & Astronomy Faculty Publications

© 2021, The Author(s). The discovery of topological quantum states marks a new chapter in both condensed matter physics and materials sciences. By analogy to spin electronic system, topological concepts have been extended into phonons, boosting the birth of topological phononics (TPs). Here, we present a high-throughput screening and data-driven approach to compute and evaluate TPs among over 10,000 real materials. We have discovered 5014 TP materials and grouped them into two main classes of Weyl and nodal-line (ring) TPs. We have clarified the physical mechanism for the occurrence of single Weyl, high degenerate Weyl, individual nodal-line (ring), nodal-link ...


Spin Superfluidity In Noncollinear Antiferromagnets, Bo Li, Alexey Kovalev 2021 University of Nebraska - Lincoln

Spin Superfluidity In Noncollinear Antiferromagnets, Bo Li, Alexey Kovalev

Faculty Publications, Department of Physics and Astronomy

We explore the spin superfluid transport in exchange interaction dominated three-sublattice antiferromagnets. The system in the long-wavelength regime is described by an $SO(3)$ invariant field theory. Additional corrections from Dzyaloshinskii-Moriya interactions or anisotropies can break the symmetry; however, the system still approximately holds a $U(1)$-rotation symmetry. Thus, the power-law spatial decay signature of spin superfluidity is identified in a nonlocal-measurement setup where the spin injection is described by the generalized spin-mixing conductance. We suggest iron jarosites as promising material candidates for realizing our proposal.


Ultrafast Investigation And Control Of Dirac And Weyl Semimetals, Christopher P. Weber 2021 Santa Clara University

Ultrafast Investigation And Control Of Dirac And Weyl Semimetals, Christopher P. Weber

Physics

Ultrafast experiments using sub-picosecond pulses of light are poised to play an important role in the study and use of topological materials and, particularly, of the three-dimensional Dirac and Weyl semimetals. Many of these materials’ characteristic properties—their linear band dispersion, Berry curvature, near-vanishing density of states at the Fermi energy, and sensitivity to crystalline and time-reversal symmetries—are closely related to their sub- and few-picosecond response to light. Ultrafast measurements offer the opportunity to explore excitonic instabilities and transient photocurrents, the latter depending on the Berry curvature and possibly quantized by fundamental constants. Optical pulses may, through Floquet effects ...


Predicted Net Flux Versus Pressure Profiles During A Probe Descent Into Uranus’S Atmosphere, Meredith Wieber, Shahid Aslam, Maarten Roos, Patrick Irwin, Geronimo Villanueva 2021 University of Minnesota, Department of Physics and Astronomy

Predicted Net Flux Versus Pressure Profiles During A Probe Descent Into Uranus’S Atmosphere, Meredith Wieber, Shahid Aslam, Maarten Roos, Patrick Irwin, Geronimo Villanueva

Society of Physics Students Regional Meeting

The responsivity of the proposed Net Flux Radiometer (NFR) for the Ice Giants was examined, using a specialty browser tool. This tool takes simulated spectra of Uranus, along with specific parameters of the NFR, and applies Net Flux calculations in order to produce a net flux profile, a simulated view of what the NFR probe would observe as it plunged into Uranus’s atmosphere. The efforts of this project led to a redesign of the NFR to include an increase in the FOV of the radiation-collection windows from 5° to 10°, as well as the selection of spectral bandwidths for ...


Tagging Pb-214 Decay Events Via Toy Monte Carlo Method, Samuel Schleich 2021 South Dakota School of Mines and Technology, Physics Department

Tagging Pb-214 Decay Events Via Toy Monte Carlo Method, Samuel Schleich

Society of Physics Students Regional Meeting

Pb-214 β-decay events within a liquid xenon time projection chamber can often look identical to the signature of a WIMP interaction, which causes false positives in the search for dark matter. To combat this, we can “tag” decay events of the Rn-222 decay chain, which is based on the timing and position of decay events. My algorithm pieced these events together like puzzle pieces to determine the validity of Pb-214 β-decay events. Using a Toy Monte Carlo model, I was able to simulate both the Rn-222 decay chain and begin to tag decay events to eliminate false positives.


Simulating Griffiths Phase Behavior, Aaron Janaszak 2021 University of Northern Iowa

Simulating Griffiths Phase Behavior, Aaron Janaszak

Society of Physics Students Regional Meeting

The Griffiths Phase is a result of a spontaneous increase in the overall magnetization of the system primarily influenced by the rare, large clusters transitioning to a ferromagnetic state at the Curie temperature. Approaching this computationally, we were able to create a MATLAB program that exhibits this trend by using the Langevin function to simulate clusters. Modifying variables resulted in behaviors similar to that experienced in a laboratory setting, lending support to the veracity of the model. Further refinement of the computational model could allow in-depth exploration and lead to a better understanding of the Griffiths Phase.


Insights Into Searches For Anisotropies In The Nanohertz Gravitational-Wave Background, Y. Ali-Haïmoud, Tristan L. Smith, C. M. F. Mingarelli 2021 Swarthmore College

Insights Into Searches For Anisotropies In The Nanohertz Gravitational-Wave Background, Y. Ali-Haïmoud, Tristan L. Smith, C. M. F. Mingarelli

Physics & Astronomy Faculty Works

Within the next several years pulsar timing arrays (PTAs) are positioned to detect the stochastic gravitational-wave background (GWB) likely produced by the collection of inspiralling supermassive black holes binaries, and potentially constrain some exotic physics. So far most of the pulsar timing data analysis has focused on the monopole of the GWB, assuming it is perfectly isotropic. The natural next step is to search for anisotropies in the GWB. In this paper, we use the recently developed PTA Fisher matrix to gain insights into optimal search strategies for GWB anisotropies. For concreteness, we apply our results to the European Pulsar ...


Determination Of The Rydberg Constant From The Emission Spectra Of H And He+, Kyle D. Shaffer 2021 Department of Chemistry, West Chester University of Pennsylvania

Determination Of The Rydberg Constant From The Emission Spectra Of H And He+, Kyle D. Shaffer

Ramifications

Abstract

In this experiment, the Rydberg constants for the hydrogen atom and He+ were determined by analysis of the emission spectra of Hand He, respectively, in comparison to the principal quantum numbers of each transition. Using both a hydrogen and then a helium atomic lamp attached to a 0.5 m grating spectrometer and a photomultiplier detector (PMT), a change in voltage detected by the PMT can be paired with a corresponding wavelength passing through the spectrometer from each emission peak in the visible to ultraviolet range. The peaks acquired from this change in voltage were analyzed to find their ...


Magnetic Crystalline-Symmetry-Protected Axion Electrodynamics And Field-Tunable Unpinned Dirac Cones In Euin2as2, Simon X. M. Riberolles, Thais V. Trevisan, Brinda Kuthanazhi, T. W. Heitman, F. Ye, David C. Johnston, Sergey L. Bud’ko, D. H. Ryan, Paul C. Canfield, Andreas Kreyssig, A. Vishwanath, Robert J. McQueeney, Lin-Lin Wang, Peter P. Orth, Benjamin G. Ueland 2021 Ames Laboratory

Magnetic Crystalline-Symmetry-Protected Axion Electrodynamics And Field-Tunable Unpinned Dirac Cones In Euin2as2, Simon X. M. Riberolles, Thais V. Trevisan, Brinda Kuthanazhi, T. W. Heitman, F. Ye, David C. Johnston, Sergey L. Bud’Ko, D. H. Ryan, Paul C. Canfield, Andreas Kreyssig, A. Vishwanath, Robert J. Mcqueeney, Lin-Lin Wang, Peter P. Orth, Benjamin G. Ueland

Physics and Astronomy Publications

Knowledge of magnetic symmetry is vital for exploiting nontrivial surface states of magnetic topological materials. EuIn2As2 is an excellent example, as it is predicted to have collinear antiferromagnetic order where the magnetic moment direction determines either a topological-crystalline-insulator phase supporting axion electrodynamics or a higher-order-topological-insulator phase with chiral hinge states. Here, we use neutron diffraction, symmetry analysis, and density functional theory results to demonstrate that EuIn2As2 actually exhibits low-symmetry helical antiferromagnetic order which makes it a stoichiometric magnetic topological-crystalline axion insulator protected by the combination of a 180∘ rotation and time-reversal symmetries: C2×T=2′. Surfaces protected by 2′ are ...


Flavor-Dependent Radiative Corrections In Coherent Elastic Neutrino-Nucleus Scattering, Oleksandr Tomalak, Pedro Machado, Vishvas Pandey, Ryan Plestid 2021 University of Kentucky

Flavor-Dependent Radiative Corrections In Coherent Elastic Neutrino-Nucleus Scattering, Oleksandr Tomalak, Pedro Machado, Vishvas Pandey, Ryan Plestid

Physics and Astronomy Faculty Publications

We calculate coherent elastic neutrino-nucleus scattering cross sections on spin-0 nuclei (e.g. 40Ar and 28Si) at energies below 100 MeV within the Standard Model and account for all effects of permille size. We provide a complete error budget including uncertainties at nuclear, nucleon, hadronic, and quark levels separately as well as perturbative error. Our calculation starts from the four-fermion effective field theory to explicitly separate heavy-particle mediated corrections (which are absorbed by Wilson coefficients) from light-particle contributions. Electrons and muons running in loops introduce a non- trivial dependence on the momentum transfer due to their relatively light ...


Avoided Ferromagnetic Quantum Critical Point In Pressurized La5 Co2 Ge3, Li Xiang, Elena Gati, Sergey L. Bud’ko, Scott M. Saunders, Paul C. Canfield 2021 Iowa State University and Ames Laboratory

Avoided Ferromagnetic Quantum Critical Point In Pressurized La5 Co2 Ge3, Li Xiang, Elena Gati, Sergey L. Bud’Ko, Scott M. Saunders, Paul C. Canfield

Ames Laboratory Accepted Manuscripts

We present the pressure-temperature phase diagram La5Co2Ge3 up to ∼5 GPa, which was constructed from magnetization, resistivity, and specific heat measurements. At ambient pressure, La5Co2Ge3 is an itinerant ferromagnet with a Curie temperature TC∼ 4 K. Upon increasing pressure up to ∼1.7 GPa, TC is suppressed down to ∼3 K. Upon further increasing pressure, our results suggest that La5Co2Ge3 enters a different low-temperature ground state. The corresponding transition temperature T∗ has a nonmonotonic pressure dependence up to ∼5 GPa. Our results demonstrate that the ferromagnetic quantum critical point in La5Co2Ge3 is avoided by the appearance of a different, likely ...


Digital Commons powered by bepress