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Full-Text Articles in Physics
Experimental And Computational Techniques In Carbon-13 Nmr, Samuel John Varner
Experimental And Computational Techniques In Carbon-13 Nmr, Samuel John Varner
Dissertations, Theses, and Masters Projects
An efficient method for calculating NMR lineshapes from anisotropic second rank tensor interactions is presented. The algorithm produces lineshapes from asymmetric tensors by summing those from symmetric tensors. This approach significantly reduces the calculation time, greatly facilitating iterative nonlinear least squares fitting of experimental spectra. This algorithm has been modified to produce partially relaxed lineshapes and spectra of partially ordered samples.;Calculations for rapidly spinning samples show that spin-lattice relaxation time ( T1Z ) anisotropy varies with the angle between the spinning axis and the external field. When the rate of molecular motion is in the extreme narrowing limit, measurement of …
Characterization Of The Physical Properties Of Iron Polyimide Nanocomposites, Russell A. Wincheski
Characterization Of The Physical Properties Of Iron Polyimide Nanocomposites, Russell A. Wincheski
Dissertations, Theses, and Masters Projects
The discovery of tunneling magneto-resistance has led to a great deal of interest in the study of ferromagnet-insulator-ferromagnet (FIF) systems due to potential sensor and magnetic storage applications. An analysis of the band structure of the 3d ferromagnets shows that the conduction electrons become spin polarized by the molecular field. The transmission coefficient of these electrons across a tunneling gap therefore depends upon the relative alignment of the molecular field between the two ferromagnets.;In this work the manufacture of such tunneling gaps through compression molding of powdered ferromagnetic iron with a high performance polyimide has been studied for the first …
Turbulence In Binary Fluid Flow Systems: A Lattice Boltzmann Approach, Darren M. Wah
Turbulence In Binary Fluid Flow Systems: A Lattice Boltzmann Approach, Darren M. Wah
Dissertations, Theses, and Masters Projects
A method for simulating a turbulent binary fluid flow system based on the Lattice Boltzmann Method (LBM) is presented. The fluid equations up to the Navier-Stokes transport level are derived for this two fluid system, and results from numerical simulations using this method are shown. Finally, grid resolution is performed in a single fluid (LBM) simulation which determines the largest valid mesh size for a simulation that seeks to resolve physical structures of all scales.
Thermoelastic And Photoelastic Full-Field Stress Measurement, Deonna Faye Woolard
Thermoelastic And Photoelastic Full-Field Stress Measurement, Deonna Faye Woolard
Dissertations, Theses, and Masters Projects
Photoelasticity is an optical technique that measures the difference of the principal stresses plus the principal stress direction. A complementary technique is thermoelasticity which measures the sum of the principal stresses. Combining these two full-field, non-contact nondestructive evaluation techniques allows the individual stress components to be measured. One of the main difficulties in merging these two measurement systems is in identifying an appropriate surface coating. Thermoelasticity demands a highly emissive surface, while photoelasticity requires a thick, stress-birefringent, transparent coating with a retro-reflective backing. Two coatings have been identified that can be used for combined thermoelastic and photoelastic stress measurements: PMMA …
Electroproduction Of Omega (783) Mesons Using Clas At Jefferson Lab, Alan Clayton Coleman
Electroproduction Of Omega (783) Mesons Using Clas At Jefferson Lab, Alan Clayton Coleman
Dissertations, Theses, and Masters Projects
Electroproduction of omega(783) mesons from a proton target has been measured in a search for so called "missing baryon resonances". A 4.0 GeV electron beam was used. The scattered electrons were measured in coincidence with the recoiling proton and the positive pion from the omega decay. Missing mass techniques were applied to identify the omega in the final state, and to reduce the rho(770) contribution. The data show the omega very clearly on a smooth background originating predominantly from three-pion phase space. Yields have been extracted, and the W and t dependencies determined. The t dependence is mostly monotonic for …
Decay Search For The Supersymmetric R(0) (Gluon Gluino) Hadron Via The Channel R(0) Going To Positive Pion Negative Pion Photino, Kevin Michael Hern
Decay Search For The Supersymmetric R(0) (Gluon Gluino) Hadron Via The Channel R(0) Going To Positive Pion Negative Pion Photino, Kevin Michael Hern
Dissertations, Theses, and Masters Projects
There has been recent theoretical interest in supersymmetry breaking scenarios in which the gauginos are light compared to the squarks. One prediction of these light gluino models is the existence of the R 0 hadron (gg?£). Brookhaven National Laboratory AGS Experiment 935 (E935) searched for light gluinos through the appearance of pi+pi- pairs with invariant mass Mpipi > 545 MeV/c2 in a high flux neutral beam. The search has yielded one candidate event. This event is consistent with the anticipated background of 1.4 events due to interactions of neutrons in the beam with the residual gas in the evacuated decay region. …