Physics Commons^™

A Progress Report On Numerical Methods For Bgk-Type Kinetic Equations, Evan Habbershaw, Steven M. Wise

Faculty Publications and Other Works -- Mathematics

In this report we review some preliminary work on the numerical solution of BGK-type kinetic equations of particle transport. Such equations model the motion of fluid particles via a density field when the kinetic theory of rarefied gases must be used in place of the continuum limit Navier-Stokes and Euler equations. The BGK-type equations describe the fluid in terms of phase space variables, and, in three space dimensions, require 6 independent phase-space variables (3 for space and 3 for velocity) for accurate simulation. This requires sophisticated numerical algorithms and efficient code to realize predictions over desired space and time scales. …

Anisotropic Magnetoexcitons In Two-Dimensional Transition Metal Trichalcogenide Semiconductors, Roman Ya. Kezerashvili, Anastasia Spiridonova

Publications and Research

Direct and indirect excitons in Rydberg states in transition metal trichalcogenide (TMTC) monolayers, bilayers, and van der Waals (vdW) heterostructures in an external magnetic field are studied within the framework of the effective mass approximation. Binding energies of magnetoexcitons are calculated using the Rytova-Keldysh potential for direct magnetoexcitons and both the Rytova-Keldysh and Coulomb potentials for indirect magnetoexcitons. We report the magnetic field energy contribution to the binding energies and diamagnetic coefficients for magnetoexcitons that depend strongly on the effective mass anisotropy of electrons and holes. The comparative study of TMTCs and phosphorene is given. In TiS3, TiSe3, and ZrSe3 …

Mach's Principle: Why Are Some Reference Frames Inertial, And Others Not?, Joseph Moonan Walbran

Scholarly Horizons: University of Minnesota, Morris Undergraduate Journal

Mach's principle is a conjecture that was popular among physicists in the early 1900s, and which still sees occasional interest today. The principle states that large accelerating masses induce a local inertial reference frame around them. This paper introduces the principle and its history, and discusses its influence on later theories, like Maxwellian theories of gravity and general relativity.

Probing Charm Quark Dynamics Via Multiparticle Correlations In Pb-Pb Collisions At √SNn =5.02 Tev, A. Tumasyan

Department of Physics and Astronomy: Faculty Publications

Multiparticle azimuthal correlations of prompt D⁰ mesons are measured in Pb-Pb collisions at a nucleon-nucleon center-of-mass energy of √^sNN = 5.02 TeV. For the first time, a four-particle cumulant method is used to extract the second Fourier coefficient of the azimuthal distribution (ν₂) of D⁰ mesons as a function of event centrality and the D⁰ transverse momentum. The ratios of the four-particle v₂ values to previously measured two-particle cumulant results provide direct experimental access to event-by-event fluctuations of charm quark azimuthal anisotropies. These ratios are also found to be comparable to …

Surpassing The Standard Quantum Limit Using An Optical Spring, Torrey Cullen

LSU Doctoral Dissertations

In 1916, Albert Einstein predicted the existence of gravitational waves based on his new theory of general relativity. He predicted an accelerating mass with a non-zero quadrupole moment would emit energy in the form of gravitational waves. Often referred to as ripples in space-time, gravitational waves are extremely small by the time reach Earth, potentially having traveled hundreds of megaparsecs. It is common for these ripples in space-time to stretch and squeeze matter 1000 times smaller than the width of a proton.
Laser interferometer observatories were first built in the 1990s in the US and Europe, and as sensitivity improvements …

Resource Estimation For Quantum Simulation Algorithms, Changhao Yi

Physics & Astronomy ETDs

A major application of quantum computers is simulating other quantum systems that are intractable to simulate classically. The broad family of algorithms for this problem go by the name of quantum simulation. Product formulas provide resource efficient and practical methods to simulate Hamiltonian dynamics. In this thesis, we study the resource estimation of quantum simulation by product formula from two aspects. First, we provide a detailed analysis of the algorithm itself. Using the effective Hamiltonian perspective, we successfully reduce the circuit complexity of quantum phase estimation and digital adiabatic simulation. Second, we analyze the performance of dynamical decoupling, a widely-used …

Asymmetric Control Of Light At The Nanoscale, Christos Argyropoulos

Department of Electrical and Computer Engineering: Faculty Publications

Breaking reciprocity at the nanoscale can produce directional formation of images due to the asymmetric nonlinear optical response of subwavelength anisotropic resonators. The self-induced passive non-reciprocity has advantages compared to magnet or time modulation approaches and may impact both classical and quantum photonics.

The Close Agn Reference Survey (Cars): Tracing The Circumnuclear Star Formation In The Super-Eddington Nls1 Mrk 1044, N. Winkel, T. A. Davis, I. Smirnova-Pinchukova, V. N. Bennert, F. Combes, M. Gaspari, K. Jahnke, J. Neumann, C. P. O'Dea, M. Pérez-Torres, M. Singha, G. R. Tremblay, H. W. Rix

Physics

Context. The host galaxy conditions for rapid supermassive black hole growth are poorly understood. Narrow-line Seyfert 1 (NLS1) galaxies often exhibit high accretion rates and are hypothesized to be prototypes of active galactic nuclei (AGN) at an early stage of their evolution.

Aims. We present adaptive optics (AO) assisted VLT MUSE NFM observations of Mrk 1044, the nearest super-Eddington accreting NLS1. Together with archival MUSE WFM data, we aim to understand the host galaxy processes that drive Mrk 1044’s black hole accretion.

Methods. We extracted the faint stellar continuum emission from the AGN-deblended host and performed spatially resolved emission line …

Modelling Spherical Aberration Detection In An Analog Holographic Wavefront Sensor, Emma Branigan, Suzanne Martin, Matthew Sheehan, Kevin Murphy

Conference Papers

The analog holographic wavefront sensor (AHWFS) is a simple and robust solution to wavefront sensing in turbulent environments. Here, the ability of a photopolymer based AHWFS to detect refractively generated spherical aberration is modelled and verified.

Modeling The Electronic Properties For Cnt Interacted With Zno, Cuo, And Co3o4, Mohamed Morsy

Nanotechnology Research Centre

No abstract provided.

Measurement Of |Vcb| Using The Semileptonic Decay Λb → Λcμνμ, Scott Edward Ely

Dissertations - ALL

A preliminary measurement of the quark-mixing parameter |Vcb| using the exclusive decay Λ0b→ Λ+c μ−νμ is presented. A sample of Λb semileptonic decays is provided by √s = 13TeV proton-proton collisions collected by the LHCb detector in 2017. Λ0b → Λ+c μ−νμX decays are identified from muon tracks, combined with a Λc baryon. The ground state Λ0b → Λ+c μ−νμ is isolated by a fit to the Λb corrected mass spectrum. The raw yield NRaw(Λ0b → Λ+c μ−νμ) is corrected, and the semileptonic width ΓMeas. (Λ0b → Λ+c μ−νμ) is obtained. Lattice QCD calculations predict ΓTh.(Λ0b → Λ+c μ−νμ)/|Vcb|2. A …

Uncertainties Of The Pulsed Electroacoustic Method: Peak Positions Of Embedded Charge Distributions, Zachary Gibson, J. R. Dennison

Physics Student Research

The pulsed electroacoustic (PEA) method allows for nondestructive measurements of internal charge distributions in dielectric materials. These measurements have been paramount in understanding and mitigating charge accumulation, aging, and electrostatic discharge in materials for various applications. This study aims to examine more closely the uncertainties of pulsed electroacoustic measurements. The first few moments of a charge distribution are directly related to the magnitude, peak position, full-width-at-half-maximum, and skewness. The uncertainty in the magnitude of the charge distribution is often quite large, but the peak position can be determined with a precision of <1 μm. This has been demonstrated in our lab with repeated PEA measurements of polyether-etherketone (PEEK) with internal charge present. This precision is further validated with measurements of PEEK irradiated with differing doses of 50 keV incident electrons, resulting in peak positions that differ by only a few μm. A final test is given by measurements monitoring the slow migration of the charge distributions in these irradiated samples over several months. The measured shifts in the peak position of the charge distributions are ≤1 μm. Though the spatial resolutions of PEA measurements are typically ~10 μm, as defined by the full- width-at-half-maximum of the leading interfacial peak, the precision of the peak position can be more than an order of magnitude greater. The statistical analysis of the repeated measurements to determine uncertainties, as well as the validation measurements, demonstrate the high precision determination of the peak position of embedded charge distributions.

Study Of Radiative Corrections In The Muon Scattering Experiment, Lin Li

Theses and Dissertations

The root-mean-square (rms) radius of the proton charge is a fundamental quantity. In 2010, the studies of muonic hydrogen with high precision found a notably smaller value than the one from earlier non-muonic measurements. This discrepancy has led to theoretical and experimental investigations. A missing measurement in determining the proton radius is muon scattering, a measurement that the MUon Scattering Experiment (MUSE) collaboration proposed at Paul Scherrer Institute (PSI). MUSE will measure elastic electron-proton and muon-proton scattering data with positively and negatively charged beams in a four-momentum-transfer square range from Q2 = 0.002 to 0.08 GeV² . Each of …

Coexistence Of Extended And Localized States In The One-Dimensional Non-Hermitian Anderson Model, Cem Yuce, Hamidreza Ramezani

Physics and Astronomy Faculty Publications and Presentations

In one-dimensional Hermitian tight-binding models, mobility edges separating extended and localized states can appear in the presence of properly engineered quasiperiodical potentials and coupling constants. On the other hand, mobility edges do not exist in a one-dimensional Anderson lattice since localization occurs whenever a diagonal disorder through random numbers is introduced. Here we consider a nonreciprocal non-Hermitian lattice and show that the coexistence of extended and localized states appears with or without diagonal disorder in the topologically nontrivial region. We discuss that the mobility edges appear basically due to the boundary condition sensitivity of the nonreciprocal non-Hermitian lattice.

Characterization Of Scintillation Light In Large Liquid Argon Detectors And The Implications For Proton Decay Searches, Kyle Spurgeon

Dissertations - ALL

The Deep Underground Neutrino Experiment (DUNE) is a planned long baseline neutrino experi- ment. The detector will be comprised of four modules with 10kt of active volume each, making it an ideal target to neutrino oscillation physics and searches for proton decay. ProtoDUNE-SP was a single-phase liquid argon time projection chamber - a prototype for the first far detector module of DUNE with an active volume of 700 tons operating until 2020. It was installed at the CERN Neutrino Platform and took particle beam and cosmic ray data over its two year lifespan. Liquid argon scin- tillation light is still …

Constraining Beam Backgrounds And Analyzing The Detector Response In A Test Beam With The Nova Experiment, Abhilash Yallappa Dombara

Dissertations - ALL

NOvA is a long-baseline neutrino oscillation experiment with two functionallyidentical detectors with the Near Detector at Fermilab, Illinois, and the Far Detector at Ash River, Minnesota. NOvA measures the rate of muon neutrino disappearance and electron neutrino appearance using muon neutrinos generated by the NuMI beam from the Accelerator Division(AD), thus NOvA measures neutrino oscillation parameters in the Pontecorvo-Maki- Nakagawa-Sakata matrix. The main experimental goal of NOvA is to determine the mass hierarchy, probe Charge-Parity violation and measure sin2 θ23 precisely. In this dissertation, the experimental setup, the latest analysis methods used in NOvA, and its results from analyzing 6 …

Membrane Elasticity Modulated By Cholesterol In Model Of Porcine Eye Lens-Lipid Membrane, Nawal K. Khadka, Max-Florian Mortimer, Mason Marosvari, Raju Timsina, Laxman Mainali

Physics Faculty Publications and Presentations

Experimental evidence shows that the eye lens loses its elasticity dramatically with age. It has also been reported that the cholesterol (Chol) content in the eye lens fiber cell plasma membrane increases significantly with age. High Chol content leads to the formation of cholesterol bilayer domains (CBDs) in the lens membrane. The role of high Chol associated with lens elasticity is unclear. The purpose of this research is to investigate the membrane elasticity of the model of porcine lens-lipid (MPLL) membrane with increasing Chol content to elucidate the role of high Chol in lens membrane elasticity. In this study, we …

Precision Determination Of The Neutral Weak Form Factor Of ^48ca, D. Adhikari, (...), David S. Armstrong, Et Al.

Arts & Sciences Articles

We report a precise measurement of the parity-violating (PV) asymmetry APV in the elastic scattering of longitudinally polarized electrons from 48Ca. We measure APV=2668±106(stat)±40(syst) parts per billion, leading to an extraction of the neutral weak form factor FW(q=0.8733  fm−1)=0.1304±0.0052(stat)±0.0020(syst) and the charge minus the weak form factor Fch−FW=0.0277±0.0055. The resulting neutron skin thickness Rn−Rp=0.121±0.026(exp)±0.024(model)  fm is relatively thin yet consistent with many model calculations. The combined CREX and PREX results will have implications for future energy density functional calculations and on the density dependence of the symmetry energy of nuclear matter.

Beyond The Petermann Limit: Prospect Of Increasing Sensor Precision Near Exceptional Points, David D. Smith, Hongrok Chang, Eugeniy E. Mikhailov, Selim M. Shahriar

Arts & Sciences Articles

Experiments near the lock-in region in maximally dissipative non-Hermitian systems, e.g., conventional laser gyroscopes near the deadband, have run up against the Petermann limit, where excess noise exactly cancels any scale-factor enhancement resulting in no overall enhancement in precision. As a result, one might be tempted to conclude that exceptional points (EPs) generally cannot be used to increase the precision of laser sensors. Indeed, using a linear eigenmode analysis we show that the Petermann limit applies not just to maximally dissipative systems, but for any type of EP, owing to the fact that EPs are rotationally invariant. It turns out, …

Frustration-Induced Diffusive Scattering Anomaly And Dimension Change In Fege₂, Y. Su, Hillary L. Smith, M. B. Stone, D. L. Abernathy, M. D. Lumsden, C. P. Adams, C. Li

Physics & Astronomy Faculty Works

Magnetic frustration, arising from the competition of exchange interactions, has received great attention because of its relevance to exotic quantum phenomena in materials. In the current work, we report an unusual checkerboard-shaped scattering anomaly in FeGe₂, far from the known incommensurate magnetic satellite peaks, by inelastic neutron scattering. More surprisingly, such phenomenon appears as spin dynamics at low temperature, but it becomes prominent above Néel transition as elastic scattering. A model Hamiltonian that includes an intraplane next-nearest neighbor was proposed and such anomaly is attributed to the near-perfect magnetic frustration and the emergence of unexpected two-dimensional magnetic order in the …

Crosssections, Summer 2022, University Of Northern Iowa. Department Of Physics.

CrossSections

Contents:

A Message from the Department Head, Dr. Paul Shand ---- 1
Faculty Profile - Jeff Morgan ---- 3
Department Happenings ---- 5
Student Profile - Aaron Kirchman ---- 8
Student Focus ---- 10
Physics Education ---- 12
Alumni Profile - Dr. Tyler Rash ---- 14
Alumni News ---- 15
Donor Feature ---- 16
New Physics ---- 18

Evaluation Of Silver Nanoparticles Attached To Methylene Blue As An Antimicrobial Agent And Its Cytotoxicity, Somon Hakimov

Masters Theses & Specialist Projects

Antibiotics resistance is considered as one of the greatest public health challenges of our time. In this work, we have synthesized silver nanoparticles (Ag NPs) using pulsed liquid ablation in different medium of growth and later combined with methylene blue (MB) to evaluate its potential as an effective photodynamic therapy agent. Ag NPs were synthesized by pulsed laser ablation technique in Polyvinylpyrrolidone (PVP), citrate, and Polyvinyl alcohol (PVA). The Ag NPs were characterized using transmission electron microscopy (TEM), UV-Visible (UV-Vis), and photoluminescence (PL) spectra. Next, Ag NPs were coupled with MB and used to deactivate the Gram-negative bacteria, Escherichia coli …

Quantum Oscillations Of The J=3/2 Fermi Surface In The Topological Semimetal Yptbi, Hyunsoo Kim, Junhyun Lee, Halyna Hodovanets, Kefeng Wang, Jay D. Sau, Johnpierre Paglione

Physics Faculty Research & Creative Works

The bismuth-based half-Heusler materials host a nontrivial topological band structure, unconventional superconductivity, and large spin-orbit coupling in a system with very low electron density. In particular, the inversion of p-orbital-derived bands with an effective angular momentum j of up to 3/2 is thought to play a central role in anomalous Cooper pairing in the cubic half-Heusler semimetal YPtBi, which is thought to be the first "high-spin" superconductor. Here, we report an extensive study of the angular dependence of quantum oscillations (QOs) in the electrical conductivity of YPtBi, revealing an anomalous Shubnikov-de Haas effect consistent with the presence of a coherent …

Foldy-Wouthuysen Transformation In Strong Magnetic Fields And Relativistic Corrections For Quantum Cyclotron Energy Levels, Albert Wienczek, Christopher Moore, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

We carry out a direct iterative Foldy-Wouthuysen transformation of a general Dirac Hamiltonian coupled to an electromagnetic field, including the anomalous magnetic moment. The transformation is carried out through an iterative disentangling of the particle and antiparticle Hamiltonians in the expansion for higher orders of the momenta. The time-derivative term from the unitary transformation is found to be crucial in supplementing the transverse component of the electric field in higher orders. Final expressions are obtained for general combined electric and magnetic fields, including strong magnetic fields. The time derivative of the electric field is shown to enter only in the …

Structure And Electronic Properties Of Amorphous Strontium Titanate, Julia E. Medvedeva, Bishal Bhattarai, Ivan A. Zhuravlev, Federico Motti, Piero Torelli, Anita Guarino, Andreas Klein, Emiliano Di Gennaro, Fabio Miletto Granozio

Physics Faculty Research & Creative Works

Understanding the short-range structure of an amorphous material is the first step in predicting its macroscopic properties. Amorphous strontium titanate (a-STO) presents a unique challenge due to contradictory experimental findings regarding the local oxygen environment of titanium, concluded to be either tetrahedral or octahedral. To elucidate the discrepancy, 72 models of a-STO with density ranging from the crystalline value 5.12 to 3.07g/cm3 were prepared using ab initio molecular dynamics liquid-quench simulations and characterized by extended x-ray absorption fine structure (EXAFS) for both Ti and Sr K edge. An excellent agreement between the calculated and two independent experimental EXAFS measurements demonstrates …

Localized Surface Plasmon Resonance Of Copper Nanoparticles Using Finite Element Method, Samaya El Samad, Salem Marhaba

BAU Journal - Science and Technology

The aim of this paper is to study the interaction of the electromagnetic wave with plasmonic nanoparticles. Localized Surface Plasmon resonance (LSPR) characteristics are governed by the intrinsic properties of the nanoparticle (size, shape and dielectric environment). The extinction cross-section spectra of Cu nanoparticles are calculated using finite element method (FEM). By increasing both the size of the nanoparticle and the dielectric environment, the simulations show a red-shifting and broadening on the LSPR spectrum with enhancement of the spectral amplitude. The extinction cross section spectra are calculated using polarized light for non-spherical or assembled nanoparticles. We investigated the LSPR of …

Nuclear Fuel Cycle: Safe Management Of Spent Nuclear Fuel, Robert L. Sindelar

Journal of the South Carolina Academy of Science

The aim for storage of spent nuclear fuel (SNF) either in wet or in dry storage systems is to ensure general safety objectives are met throughout a desired storage period. Staff at the Savannah River National Laboratory (SRNL), in collaborations with partners at other national laboratories, industry research organizations, and the University of South Carolina (UofSC), have performed materials aging testing and analyses, and have established nuclear materials aging management programs to support extended periods of safe storage of research reactor (RR) SNF and of commercial power reactor (PR) SNF pending ultimate disposal. Several example challenges include susceptibility of aluminum …

Method Of Hybrid Control Based Of Dynamic Objects Of Neuro-Fuzzy Inference, Noilakhon Yakubova

Karakalpak Scientific Journal

The Results of interaction of the work is development of a method of control that allows simplifying, automating and unifying the process of design of the hybrid systems which are a basis of modern automation. To achieve a definite purpose, a method of control of a technical object based on the construction of an adaptive system of neuro-fuzzy inference is developed. The objects of the system of neuro-fuzzy inference are the classical and neuro-fuzzy models of control. Information exchange between models is provided by means of the developed hybrid control system. The result of the interaction of the two models …

Application Of A Synergetic Approach To The Problem Of Synthesizing An Intelligent Control System For Chemical Reactors, Komil Usmanov

Karakalpak Scientific Journal

The article deals with the synthesis of effective algorithms for controlling a chemical reactor and developed a intelligent synergistic controller for a class of indefinite nonlinear dynamic systems. A synergetic control scheme is proposed for solving the control problem for nonlinear systems. Non-linear systems with configurations and parameters that change over time require a completely non-linear model and adaptive control scheme for a practical operating environment. The synthesis of control laws is performed by the method of analytical design of aggregated controllers (ADAR).

Development Of The Implementation Of Iot Monitoring System Based On Node-Red Technology, Anvar Kabulov, Inomjon Yarashov, Salamat Mirzataev

Karakalpak Scientific Journal

This article describes how to design and implement a process for storing environmental information in a database using the Internet of Things. The problems that need to be solved with the help of this IoT system are the growing demand for forecasts in the world, the demand of the world market for a new sustainable method of implementing the digitization environment through the Internet of Things. The design was implemented using Arduino, Node-Red and sensors, selected when choosing a component based on the required parameters and sent to the database for monitoring and processing. A study of previous work and …