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Full-Text Articles in Physics

The Physics Of Music Course As An Introduction To Science, Gordon Ramsey Sep 2014

The Physics Of Music Course As An Introduction To Science, Gordon Ramsey

Physics: Faculty Publications and Other Works

Our Physics of Music course is an integration of physics and music. We start with the mathematical structure of music, including scales, harmonies and chords. We discuss musical styles and how they differ. After an introduction of physics concepts, including waves,resonances, forces, energy and fluid flow, the physical structure of instruments in the various groups are studied. Connection is made of the instruments and how they reproduce the mathematical nature of music. Finally, venue acoustics are investigated. The course integrates different styles of learning by integrating different learning modes. The classes include lecture/demonstration, discussion, in-class laboratories and a final individual …


Strong-Disorder Magnetic Quantum Phase Transitions: Status And New Developments, Thomas Vojta Sep 2014

Strong-Disorder Magnetic Quantum Phase Transitions: Status And New Developments, Thomas Vojta

Physics Faculty Research & Creative Works

This article reviews the unconventional effects of random disorder on magnetic quantum phase transitions, focusing on a number of new experimental and theoretical developments during the last three years. On the theory side, we address smeared quantum phase transitions tuned by changing the chemical composition, for example in alloys of the type A1-xBx. We also discuss how the interplay of order parameter conservation and overdamped dynamics leads to enhanced quantum Griffiths singularities in disordered metallic ferromagnets. Finally, we discuss a semiclassical theory of transport properties in quantum Griffiths phases. Experimental examples include the ruthenates Sr1-x …


Rare Regions And Griffiths Singularities At A Clean Critical Point: The Five-Dimensional Disordered Contact Process, Thomas Vojta, John Igo, José A. Hoyos Jul 2014

Rare Regions And Griffiths Singularities At A Clean Critical Point: The Five-Dimensional Disordered Contact Process, Thomas Vojta, John Igo, José A. Hoyos

Physics Faculty Research & Creative Works

We investigate the nonequilibrium phase transition of the disordered contact process in five space dimensions by means of optimal fluctuation theory and Monte Carlo simulations. We find that the critical behavior is of mean-field type, i.e., identical to that of the clean five-dimensional contact process. It is accompanied by off-critical power-law Griffiths singularities whose dynamical exponent z' saturates at a finite value as the transition is approached. These findings resolve the apparent contradiction between the Harris criterion, which implies that weak disorder is renormalization-group irrelevant, and the rare-region classification, which predicts unconventional behavior. We confirm and illustrate our theory by …


The Structure Of D₂O-Nonane Nanodroplets, Harshad Pathak, Abdalla Obeidat, Gerald Wilemski, Barbara Wyslouzil Jun 2014

The Structure Of D₂O-Nonane Nanodroplets, Harshad Pathak, Abdalla Obeidat, Gerald Wilemski, Barbara Wyslouzil

Physics Faculty Research & Creative Works

We study the internal structure of nanometer-sized D2O-nonane aerosol droplets formed in supersonic nozzle expansions using a variety of experimental techniques including small angle X-ray scattering (SAXS). By fitting the SAXS spectra to a wide range of droplet structure models, we find that the experimental results are inconsistent with mixed droplets that form aqueous core-organic shell structures, but are quite consistent with spherically asymmetric lens-on-sphere structures. The structure that agrees best with the SAXS data and Fourier transform infra-red spectroscopy measurements is that of a nonane lens on a sphere of D2O with a contact angle in the …


Increasing Interest Of Young Women In Engineering, Diane Hinterlong, Branson Lawrence, Purva Devol Apr 2014

Increasing Interest Of Young Women In Engineering, Diane Hinterlong, Branson Lawrence, Purva Devol

Publications & Research

The internationally recognized Illinois Mathematics and Science Academy (IMSA) develops creative, ethical leaders in science, technology, engineering and mathematics. As a teaching and learning laboratory created by the State of Illinois, IMSA enrolls academically talented Illinois students in grades 10 through 12 in its advanced, residential college preparatory program. IMSA also serves thousands of educators and students in Illinois and beyond through innovative instructional programs that foster imagination and inquiry. IMSA also advances education through research, groundbreaking ventures and strategic partnerships.


Multiple Transient Memories In Experiments On Sheared Non-Brownian Suspensions, Joseph Paulsen, Nathan C. Keim, Sidney R. Nagel Jan 2014

Multiple Transient Memories In Experiments On Sheared Non-Brownian Suspensions, Joseph Paulsen, Nathan C. Keim, Sidney R. Nagel

Physics - All Scholarship

A system with multiple transient memories can remember a set of inputs but subsequently forgets almost all of them, even as they are continually applied. If noise is added, the system can store all memories indefinitely. The phenomenon has recently been predicted for cyclically sheared non-Brownian suspensions. Here we present experiments on such suspensions, finding behavior consistent with multiple transient memories and showing how memories can be stabilized by noise.


Scattering Of A Point-Like Anapole, Kyle Whitcomb Jan 2014

Scattering Of A Point-Like Anapole, Kyle Whitcomb

Summer Research

Majorana fermions, being elementary particles with half-integer spin which are their own antiparticle, are a hypothetical class of particle that are not currently in the Standard Model of particle physics. This research investigates the properties of Majorana fermions by calculating the scattering angle due to electromagnetic interactions between Majorana fermions and electrons. Since Majorana fermions interact solely via an electromagnetic term called the anapole moment, which is relatively weak compared to other terms, this problem was solved in the framework of quantum electrodynamics modeling the Majorana fermion as a point-like anapole. Additionally, since there is no restriction on the mass …


Narrow-Band Emission In Thomson Sources Operating In The High-Field Regime, Balša Terzić, Kirsten Deitrick, Alicia S. Hofler, Geoffrey A. Krafft Jan 2014

Narrow-Band Emission In Thomson Sources Operating In The High-Field Regime, Balša Terzić, Kirsten Deitrick, Alicia S. Hofler, Geoffrey A. Krafft

Physics Faculty Publications

We present a novel and quite general analysis of the interaction of a high-field chirped laser pulse and a relativistic electron, in which exquisite control of the spectral brilliance of the up-shifted Thomson-scattered photon is shown to be possible. Normally, when Thomson scattering occurs at high field strengths, there is ponderomotive line broadening in the scattered radiation. This effect makes the bandwidth too large for some applications and reduces the spectral brilliance. We show that such broadening can be corrected and eliminated by suitable frequency modulation of the incident laser pulse. Furthermore, we suggest a practical realization of this compensation …


Beam-Spin Asymmetries From Semi-Inclusive Pion Electroproduction, K. P. Adhikari, M. J. Amaryan, C. Hyde, S. Koirala, S. E. Kuhn, L. B. Weinstein, Et Al., The Clas Collaboration Jan 2014

Beam-Spin Asymmetries From Semi-Inclusive Pion Electroproduction, K. P. Adhikari, M. J. Amaryan, C. Hyde, S. Koirala, S. E. Kuhn, L. B. Weinstein, Et Al., The Clas Collaboration

Physics Faculty Publications

We have measured the moment Asin ɸLU corresponding to the polarized electron beam-spin asymmetry in semi-inclusive deep inelastic scattering. Asin ɸLU is a twist-3 quantity providing information about quark-gluon correlations. Data were taken with the CLAS Spectrometer at Jefferson Lab using a 5.498 GeV longitudinally polarized electron beam and an unpolarized liquid hydrogen target. All three pion channels (π+0 and π-) were measured simultaneously over a large range of kinematics within the virtuality range Q2 ≈ 1.0- 4.5 GeV2. The observable was measured with better than 1% statistical …


Publisher’S Note: Data Analysis Techniques, Differential Cross Sections, And Spin Density Matrix Elements For The Reaction 𝛾p -> Φp (Phys. Rev. C. Vol 89, 055208, 2014), K. P. Adhikari, D. Adikaram, M. J. Amaryan, C. E. Hyde, A. Klein, S. Koirala, S. E. Kuhn, M. Mayer, I. Niculescu, J. Zhang, Et Al., The Clas Collaboration Jan 2014

Publisher’S Note: Data Analysis Techniques, Differential Cross Sections, And Spin Density Matrix Elements For The Reaction 𝛾p -> Φp (Phys. Rev. C. Vol 89, 055208, 2014), K. P. Adhikari, D. Adikaram, M. J. Amaryan, C. E. Hyde, A. Klein, S. Koirala, S. E. Kuhn, M. Mayer, I. Niculescu, J. Zhang, Et Al., The Clas Collaboration

Physics Faculty Publications

No abstract provided.


A First-Principles Computational Study Of Structural And Elastic Properties Of Zno, Jeevake Attapattu, Changfeng Chen Jan 2014

A First-Principles Computational Study Of Structural And Elastic Properties Of Zno, Jeevake Attapattu, Changfeng Chen

McNair Poster Presentations

The purpose of this study is to determine structural and mechanical properties of zinc oxide (ZnO) using first-principles computational methods. ZnO is a semiconductor widely used in many electronic and optical applications. ZnO is also economically and environmentally desirable – first, both the constituent elements are abundant on Earth and therefore inexpensive for large-scale applications; second, it is non- toxic. The most significant contribution of this study is the simulations of the high-pressure phases. These high-pressure simulations are important because the rock salt phase of ZnO obtained at high pressure can be recovered at ambient pressure, and this new structural …


Data Analysis Techniques, Differential Cross Sections, And Spin Density Matrix Elements For The Reaction 𝛾p → Φp, K. P. Adhikari, D. Adikaram, M. J. Amaryan, C. E. Hyde, S. Koirala, S. E. Kuhn, M. Mayer, I. Niculescu, Et Al., The Clas Collaboration Jan 2014

Data Analysis Techniques, Differential Cross Sections, And Spin Density Matrix Elements For The Reaction 𝛾p → Φp, K. P. Adhikari, D. Adikaram, M. J. Amaryan, C. E. Hyde, S. Koirala, S. E. Kuhn, M. Mayer, I. Niculescu, Et Al., The Clas Collaboration

Physics Faculty Publications

High-statistics measurements of differential cross sections and spin density matrix elements for the reaction γp→ϕp have been made using the CLAS detector at Jefferson Lab. We cover center-of-mass energies (√s) from 1.97 to 2.84 GeV, with an extensive coverage in the ϕ production angle. The high statistics of the data sample made it necessary to carefully account for the interplay between the ϕ natural lineshape and effects of the detector resolution, that are found to be comparable in magnitude. We study both the charged- (ϕ→K+K) and neutral- (ϕ→K0SK0L) K→ …


Scalar Wave Scattering By Two-Layer Radial Inhomogeneities, Umaporn Nuntaplook, John Adam Jan 2014

Scalar Wave Scattering By Two-Layer Radial Inhomogeneities, Umaporn Nuntaplook, John Adam

Mathematics & Statistics Faculty Publications

It is shown that the iteration technique gives a better approximation for the problem with long wavelengths.