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Articles 1 - 6 of 6
Full-Text Articles in Physical Sciences and Mathematics
Gravitational Ultrarelativistic Interaction Of Classical Particles In The Context Of Unification Of Interactions, R. Plyatsko, Oleksa-Myron Bilaniuk
Gravitational Ultrarelativistic Interaction Of Classical Particles In The Context Of Unification Of Interactions, R. Plyatsko, Oleksa-Myron Bilaniuk
Physics & Astronomy Faculty Works
The response of the ultrarelativistic particle with spin in a Schwarzschild field to the gravitomagnetic components as measured by the comoving observer is investigated. The dependence of the particle's spin–orbit acceleration on the Lorentz γ-factor and the spin orientation is studied. The concrete circular ultrarelativistic orbit of radius r = 3 m is considered as a partial solution of the Mathisson–Papapetrou equations and as the corresponding high-energy quantum state of the Dirac particle. Numerical estimates for protons and electrons near black holes are given. A tendency of gravitational and electromagnetic interactions to approach in quantitative terms at ultrarelativistic velocities is …
Field-Dependent Tilt And Birefringence Of Electroclinic Liquid Crystals: Theory And Experiment, J. V. Selinger, Peter J. Collings, R. Shashidhar
Field-Dependent Tilt And Birefringence Of Electroclinic Liquid Crystals: Theory And Experiment, J. V. Selinger, Peter J. Collings, R. Shashidhar
Physics & Astronomy Faculty Works
An unresolved issue in the theory of liquid crystals is the molecular basis of the electroclinic effect in the smectic-A phase. Recent x-ray scattering experiments suggest that, in a class of siloxane-containing liquid crystals, an electric field changes a state of disordered molecular tilt in random directions into a state of ordered tilt in one direction. To investigate this issue, we measure the optical tilt and birefringence of these liquid crystals as functions of field and temperature, and we develop a theory for the distribution of molecular orientations under a field. A comparison of theory and experiment confirms that these …
Energetic Particles And Magnetohydrodynamic Activity In The Swarthmore Spheromak Experiment, G. Qin, Vyacheslav S. Lukin , '00, C. D. Cothran, Michael R. Brown, W. H. Matthaeus
Energetic Particles And Magnetohydrodynamic Activity In The Swarthmore Spheromak Experiment, G. Qin, Vyacheslav S. Lukin , '00, C. D. Cothran, Michael R. Brown, W. H. Matthaeus
Physics & Astronomy Faculty Works
Results from the Swarthmore Spheromak Experiment (SSX) [M. R. Brown, Phys. Plasmas 6, 1717 (1999)] indicate that formation and partial merging of two spheromak plasmas can be described well by a magnetohydrodynamic (MHD) picture in which there is substantial evolution towards force free states within each vessel, while reconnection activity, also described reasonably well by MHD, occurs in the region of interaction. MHD simulations [V. S. Lukin , Phys. Plasmas 8, 1600 (2001)] support and provide further detail to this interpretation. In the present study, test particle equations are integrated using MHD data from SSX simulations to further understand the …
Computational Study Of Molecular Hydrogen In Zeolite Na-A. Ii. Density Of Rotational States And Inelastic Neutron Scattering Spectra, Jennifer A. Mackinnon , '95, J. Eckert, D. F. Coker, Amy Lisa Graves
Computational Study Of Molecular Hydrogen In Zeolite Na-A. Ii. Density Of Rotational States And Inelastic Neutron Scattering Spectra, Jennifer A. Mackinnon , '95, J. Eckert, D. F. Coker, Amy Lisa Graves
Physics & Astronomy Faculty Works
Part I of this series [J. Chem. Phys. 111, 7599 (1999)] describes a simulation of H(2) adsorbed within zeolite Na-A in which a block Lanczos procedure is used to generate the first several (9) rotational eigenstates of H(2), modeled as a rigid rotor, and equilibrated at a given temperature via Monte Carlo sampling. Here, we show that rotational states are strongly perturbed by the electrostatic fields in the solid. Wave functions and densities of rotational energy states are presented. Simulated neutron spectra are compared with inelastic neutron scattering data. Comparisons are made with IR spectra in which rotational levels may …
Numerical Modeling Of Magnetohydrodynamic Activity In The Swarthmore Spheromak Experiment, Vyacheslav S. Lukin , '00, G. Qin, W. H. Matthaeus, Michael R. Brown
Numerical Modeling Of Magnetohydrodynamic Activity In The Swarthmore Spheromak Experiment, Vyacheslav S. Lukin , '00, G. Qin, W. H. Matthaeus, Michael R. Brown
Physics & Astronomy Faculty Works
Results from a three-dimensional axisymmetric resistive magnetohydrodynamic (MHD) simulation are compared to experimental data from the Swarthmore Spheromak Experiment (SSX) [M. R. Brown, Phys. Plasmas 6, 1717 (1999)]. The MHD simulation is run under conditions and with dimensionless parameters similar to the experiment (Lundquist number S=1000, plasma beta beta =0.1). The simulation is shown to reproduce global equilibrium magnetic field profiles of the spheromaks as well as much of the detailed reconnection dynamics measured when two spheromaks are merged. It is concluded that SSX merger dynamics may be characterized as MHD reconnection, with the likelihood that extensions are needed to …
Turbulent Conductivity Measurements In A Spherical Liquid Sodium Flow, Amy Reighard , '01, Michael R. Brown
Turbulent Conductivity Measurements In A Spherical Liquid Sodium Flow, Amy Reighard , '01, Michael R. Brown
Physics & Astronomy Faculty Works
We report the first measurement of a reduction in the conductivity of liquid sodium due to turbulence in a spherical flow (the beta effect). The sodium is contained in a 0.15 m diameter sphere, typical flow speeds are about 1 m/s, and magnetic Reynold's numbers range from 1 to 8. We find a reduction from the molecular value of the conductivity of about 4%. Results are in rough agreement with simple predictions from mean-field electrodynamics.