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

Physics Commons

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

28863 Full-Text Articles 37774 Authors 4619833 Downloads 225 Institutions

All Articles in Physics

Faceted Search

28863 full-text articles. Page 1 of 770.

Investigating The Climatology Of Mesospheric And Thermospheric Gravity Waves At High Northern Latitudes, Michael Negale 2018 Utah State University

Investigating The Climatology Of Mesospheric And Thermospheric Gravity Waves At High Northern Latitudes, Michael Negale

All Graduate Theses and Dissertations

An important property of the Earth's atmosphere is its ability to support wave motions, and indeed, waves exist throughout the Earth's atmosphere at all times and all locations. What is the importance of these waves? Imagine standing on the beach as water waves come crashing into you. In this case, the waves transport energy and momentum to you, knocking you off balance. Similarly, waves in the atmosphere crash, known as breaking, but what do they crash into? They crash into the atmosphere knocking the atmosphere off balance in terms of the winds and temperatures. Although the Earth's ...


Principles Of Physics I & Ii (Vsu), Francis Flaherty, Dereth Drake, Michael Holt 2018 Valdosta State University

Principles Of Physics I & Ii (Vsu), Francis Flaherty, Dereth Drake, Michael Holt

Physics and Astronomy Grants Collections

This Grants Collection for Principles of Physics I & II was created under a Round Six ALG Textbook Transformation Grant.

Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process.

Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials:

  • Linked Syllabus
  • Initial Proposal
  • Final Report


Superpositioning High Power Lasers For Mid-Air Image Formation, Auston Viotto 2018 University of Nebraska at Omaha

Superpositioning High Power Lasers For Mid-Air Image Formation, Auston Viotto

Student Research and Creative Activity Fair

Abstract

This research evaluates different methods to create voxels, 3-dimensional pixels, in air without the need for special glasses or reflections off of surfaces. Research on the advantages of superimposing or the culmination, focusing, of laser light will be conducted. The point of superpositioning/culmination will be evaluated by the brightness of the voxel due to the Rayleigh Scatter Effect. The voxel’s brightness is dependent on the laser output strength and inversely proportional to its wavelength. Once a superimposed/culminated voxel has been created in the lab the next step will be to manipulate the location of the voxel ...


4,5-Dimethoxy-2-Nitrobenzohydrazides And 1-(1-Benzylpiperidin-4-Yl)Ethan-1-Ones As Potential Antioxidant/Cholinergic Endowed Small Molecule Leads, Rukhsar Banu, Jason Gerding, Cynthia Franklin, Donald Sikazwe, William Horton, Marianna Török, Julian Davis, Kwan H. Cheng, Muziya Nakazwe, Bereket Mochona 2018 Trinity University

4,5-Dimethoxy-2-Nitrobenzohydrazides And 1-(1-Benzylpiperidin-4-Yl)Ethan-1-Ones As Potential Antioxidant/Cholinergic Endowed Small Molecule Leads, Rukhsar Banu, Jason Gerding, Cynthia Franklin, Donald Sikazwe, William Horton, Marianna Török, Julian Davis, Kwan H. Cheng, Muziya Nakazwe, Bereket Mochona

Physics and Astronomy Faculty Research

The objective of this research is to generate leads for developing our ultimate poly-active molecules with utility in central nervous system (CNS) diseases. Indeed, poly-active molecules capable of mitigating brain free radical damage while enhancing acetylcholine signaling (via cholinesterase inhibition) are still being sought for combating Alzheimer’s disease (AD). We differentiate “poly-active” agents from “multi-target” ones by defining them as single molecular entities designed to target only specific contributory synergistic pharmacologies in a disease. For instance, in AD, free radicals either initiate or act in synergy with other pharmacologies, leading to disease worsening. For this preliminary report, a total ...


Studies Of Geometrical Profiling In Fabricated Tapered Optical Fbers Using Whispering Gallery Modes Spectroscopy, Vishnu Kavungal, Gerald Farrell, Qiang Wu, Arun Kumar Mallik, Yuliya Semenova 2018 Dublin Institute of Technology

Studies Of Geometrical Profiling In Fabricated Tapered Optical Fbers Using Whispering Gallery Modes Spectroscopy, Vishnu Kavungal, Gerald Farrell, Qiang Wu, Arun Kumar Mallik, Yuliya Semenova

Articles

This paper experimentally demonstrates a method for geometrical profiling of asymmetries in fabricated thin microfiber tapers with waist diameters ranging from ∼10 to ∼50µm with submicron accuracy. The method is based on the analysis of whispering gallery mode resonances excited in cylindrical fiber resonators as a result of evanescent coupling of light propagating through the fiber taper. The submicron accuracy of the proposed method has been verified by SEM studies. The method can be applied as a quality control tool in fabrication of microfiber based devices and sensors or for fine-tuning of microfiber fabrication set-ups.


Using An Instrumented Drone To Probe Dust Devils On Oregon’S Alvord Desert, Brian Jackson, Ralph Lorenz, Karan Davis, Brock Lipple 2018 Boise State University

Using An Instrumented Drone To Probe Dust Devils On Oregon’S Alvord Desert, Brian Jackson, Ralph Lorenz, Karan Davis, Brock Lipple

Brian Jackson

Dust devils are low-pressure, small (many to tens of meters) convective vortices powered by surface heating and rendered visible by lofted dust. Dust devils occur ubiquitously on Mars, where they may dominate the supply of atmospheric dust, and since dust contributes significantly to Mars’ atmospheric heat budget, dust devils probably play an important role in its climate. The dust-lifting capacity of a devil likely depends sensitively on its structure, particularly the wind and pressure profiles, but the exact dependencies are poorly constrained. Thus, the exact contribution to Mars’ atmosphere remains unresolved. Analog studies of terrestrial devils have provided some insights ...


Cosmic Ray Muons In The Standard Model Of Fundamental Particles, Angel Gutarra-Leon, Jorge Del Carpio Arispe, Cioli Barazandeh, Walerian Majewski 2018 George Mason University

Cosmic Ray Muons In The Standard Model Of Fundamental Particles, Angel Gutarra-Leon, Jorge Del Carpio Arispe, Cioli Barazandeh, Walerian Majewski

Exigence

Muons are one of the twelve fundamental particle types of matter, having relatively long free-particle lifetime. A muon decays into three other light particles (leptons) through action of the “weak” force, transmitted by the so-called “heavy photons” - bosons W+/W-. Muons are present in the secondary cosmic ray showers in the atmosphere and reach the sea level. By detecting the delay time between arrival of the muon and an appearance of the decay electron in our single scintillation detector, we measured the muon’s average lifetime at rest in the material of our detector. This compares well with the established ...


Physical Models Of The Toroidal Dipole, Armian Hanelli, Amanuel Eshete, Jorge Del Carpio, Walerian Majewski 2018 California Institute of Technology

Physical Models Of The Toroidal Dipole, Armian Hanelli, Amanuel Eshete, Jorge Del Carpio, Walerian Majewski

Exigence

We have investigated two models of the third elementary electromagnetic dipole, known as the toroidal dipole. Its magnetic realization is a circumferentially magnetized ring constructed of neodymium. The electric model of the dipole is a toroidal coil connected to a DC voltage. The electric and magnetic toroids produce only an inner magnetic field, inside the torus, and interact only on contact with the electric current density or when immersed in a time-dependent electric field. We studied the characteristics of a permanent-magnet toroid, and observed the influence of electric and magnetic fields on it. A static toroidal dipole moment of this ...


Optically Controlled Laser-Plasma Electron Acceleration For Compact Gamma-Ray Sources, Serge Y. Kalmykov, X. Davoine, Isaac Ghebregziabher, Bradley A. Shadwick 2018 CEA, DAM DIF

Optically Controlled Laser-Plasma Electron Acceleration For Compact Gamma-Ray Sources, Serge Y. Kalmykov, X. Davoine, Isaac Ghebregziabher, Bradley A. Shadwick

Serge Youri Kalmykov

Thomson scattering (TS) from electron beams produced in laser-plasma accelerators may generate femtosecond pulses of quasi-monochromatic, multi-MeV photons. Scaling laws suggest that reaching the necessary GeVelectron energy, with a percent-scale energy spread and five-dimensional brightness over 10^16 A/m^2, requires acceleration in centimeter-length, tenuous plasmas (n ~ 10^17 cm^-#3;3), with petawatt-class lasers. Ultrahigh per-pulse power mandates single-shot operation, frustrating applications dependent on dosage. To generate high-quality near-GeV beams at a manageable average power (thus affording kHz repetition rate), we propose acceleration in a cavity of electron density, driven with an incoherent stack of sub-Joule laser pulses ...


Damage Analysis Modified Trac Computer Program (Damtrac), George H. Baker III, Alan D. McNutt, G. Bradford Shea, David M. Rubenstein 2018 James Madison University

Damage Analysis Modified Trac Computer Program (Damtrac), George H. Baker Iii, Alan D. Mcnutt, G. Bradford Shea, David M. Rubenstein

George H Baker

A computer program tailored for EMP damage analysis of solid-state circuitry has been developed by modifying the existing TRAC network analysis program. Modification of the TRAC diode and transistor models to include breakdown parameters and the addition of a semiconductor device parameter library have greatly simplified the analyst's task. An added feature is a subroutine that automatically calculates the amplitude and duration of transient power dissipated in electronic circuit components.


Miracles, Cassi Bossong 2018 Olivet Nazarene University

Miracles, Cassi Bossong

Cassi Bossong

A poem that describes my outtake on our world and beyond.


The Associations Between Self-Reported Exposure To The Chernobyl Nuclear Disaster Zone And Mental Health Disorders In Ukraine, Matthew A. Bolt, Luralyn M. Helming, Nathan L. Tintle 2018 Dordt College

The Associations Between Self-Reported Exposure To The Chernobyl Nuclear Disaster Zone And Mental Health Disorders In Ukraine, Matthew A. Bolt, Luralyn M. Helming, Nathan L. Tintle

Faculty Work Comprehensive List

In 1986, Reactor 4 of the Chernobyl nuclear power plant near Pripyat, Ukraine exploded, releasing highly-radioactive materials into the surrounding environment. Although the physical effects of the disaster have been well-documented, a limited amount of research has been conducted on association of the disaster with long-term, clinically-diagnosable mental health disorders. According to the diathesis–stress model, the stress of potential and unknown exposure to radioactive materials and the ensuing changes to ones life or environment due to the disaster might lead those with previous vulnerabilities to fall into a poor state of mental health. Previous studies of this disaster have ...


Wholeness, Cassi Bossong 2018 Olivet Nazarene University

Wholeness, Cassi Bossong

Cassi Bossong

A poem that I have written for my love


Transport Anomalies And Marginal Fermi-Liquid Effects At A Quantum Critical Point, Dietrich Belitz, Theodore R. Kirkpatrick, Rajesh S. Narayanan, Thomas Vojta 2018 Missouri University of Science and Technology

Transport Anomalies And Marginal Fermi-Liquid Effects At A Quantum Critical Point, Dietrich Belitz, Theodore R. Kirkpatrick, Rajesh S. Narayanan, Thomas Vojta

Thomas Vojta

The conductivity and the tunneling density of states of disordered itinerant electrons in the vicinity of a ferromagnetic transition at low temperature are discussed. Critical fluctuations lead to nonanalytic frequency and temperature dependencies that are distinct from the usual long-time tail effects in a disordered Fermi liquid. The crossover between these two types of behavior is proposed as an experimental check of recent theories of the quantum ferromagnetic critical behavior. In addition, the quasiparticle properties at criticality are shown to be those of a marginal Fermi liquid.


Transport Properties In Antiferromagnetic Quantum Griffiths Phases, David Nozadze, Thomas Vojta 2018 Missouri University of Science and Technology

Transport Properties In Antiferromagnetic Quantum Griffiths Phases, David Nozadze, Thomas Vojta

Thomas Vojta

We study the electrical resistivity in the quantum Griffiths phase associated with the antiferromagnetic quantum phase transition in a metal. The resistivity is calculated by means of the semi-classical Boltzmann equation. We show that the scattering of electrons by locally ordered rare regions leads to a singular temperature dependence. The rare-region contribution to the resistivity varies as Tλ with temperature T, where λ is the usual Griffiths exponent which takes the value zero at the critical point and increases with distance from criticality. We find similar singular contributions to other transport properties such as thermal resistivity, thermopower and the Peltier ...


Random Fields At A Nonequilibrium Phase Transition, Hatem Barghathi, Thomas Vojta 2018 Missouri University of Science and Technology

Random Fields At A Nonequilibrium Phase Transition, Hatem Barghathi, Thomas Vojta

Thomas Vojta

We study nonequilibrium phase transitions in the presence of disorder that locally breaks the symmetry between two equivalent macroscopic states. In low-dimensional equilibrium systems, such random-field disorder is known to have dramatic effects: it prevents spontaneous symmetry breaking and completely destroys the phase transition. In contrast, we show that the phase transition of the one-dimensional generalized contact process persists in the presence of random-field disorder. The ultraslow dynamics in the symmetry-broken phase is described by a Sinai walk of the domain walls between two different absorbing states. We discuss the generality and limitations of our theory, and we illustrate our ...


Quantum Version Of A Spherical Model: Crossover From Quantum To Classical Critical Behavior, Thomas Vojta 2018 Missouri University of Science and Technology

Quantum Version Of A Spherical Model: Crossover From Quantum To Classical Critical Behavior, Thomas Vojta

Thomas Vojta

We investigate a quantum version of the spherical model which is obtained from the classical Berlin-Kac spherical model by a simple canonical quantization scheme. We find a complete solution of the model for short-range as well as for long-range interactions. At finite temperatures the critical behavior is the same as in the classical spherical model whereas at zero temperature we find a quantum phase transition characterized by new critical exponents. Based on a functional-integral representation of the partition function the free energy of the model is shown to be equivalent to that of the nonlinear σ model in the limit ...


Quantum Griffiths Singularities In Ferromagnetic Metals, David Nozadze, Thomas Vojta 2018 Missouri University of Science and Technology

Quantum Griffiths Singularities In Ferromagnetic Metals, David Nozadze, Thomas Vojta

Thomas Vojta

We present a theory of the quantum Griffiths phases associated with the ferromagnetic quantum phase transition in disordered metals. For Ising spin symmetry, we study the dynamics of a single rare region within the variational instanton approach. For Heisenberg symmetry, the dynamics of the rare region is studied using a renormalization group approach. In both cases, the rare region dynamics is even slower than in the usual quantum Griffiths case because the order parameter conservation of an itinerant ferromagnet hampers the relaxation of large magnetic clusters. The resulting quantum Griffiths singularities in ferromagnetic metals are stronger than power laws. For ...


Quantum Phase Transition Of The Sub-Ohmic Rotor Model, Manal Al-Ali, Thomas Vojta 2018 Missouri University of Science and Technology

Quantum Phase Transition Of The Sub-Ohmic Rotor Model, Manal Al-Ali, Thomas Vojta

Thomas Vojta

We investigate the behavior of an N-component quantum rotor coupled to a bosonic dissipative bath having a sub-Ohmic spectral density J (ω) ∝ ωs with s < 1.With increasing dissipation strength, this system undergoes a quantum phase transition from a delocalized phase to a localized phase.We determine the exact critical behavior of this transition in the large-N limit. For 1 > s > 1/2, we find nontrivial critical behavior corresponding to an interacting renormalization group fixed point, while we find mean-field behavior for s < 1/2. The results agree with those of the corresponding long-range interacting classical model. The quantum-to-classical mapping is therefore valid for the sub-Ohmic rotor model.


Quantum Phase Transition Of Itinerant Helimagnets, Thomas Vojta, Rastko Sknepnek 2018 Missouri University of Science and Technology

Quantum Phase Transition Of Itinerant Helimagnets, Thomas Vojta, Rastko Sknepnek

Thomas Vojta

We investigate the quantum phase transition of itinerant electrons from a paramagnet to a state which displays long-period helical structures due to a Dzyaloshinskii instability of the ferromagnetic state. In particular, we study how the self-generated effective long-range interaction recently identified in itinerant quantum ferromagnets is cut off by the helical ordering. We find that for a sufficiently strong Dzyaloshinskii instability the helimagnetic quantum phase transition is of second order with mean-field exponents. In contrast, for a weak Dzyaloshinskii instability the transition is analogous to that in itinerant quantum ferromagnets, i.e., it is of first order, as has been ...


Digital Commons powered by bepress