The road to peace according to Stalin and according to Lenin

https://stars.library.ucf.edu/prism/1297/thumbnail.jp

America\u27s road to socialism

https://stars.library.ucf.edu/prism/1749/thumbnail.jp

The coming American revolution

https://stars.library.ucf.edu/prism/1010/thumbnail.jp

The Debs centennial

https://stars.library.ucf.edu/prism/1741/thumbnail.jp

The Voice of socialism: Radio speeches by the Socialist Workers Party candidates in the 1948 election

https://stars.library.ucf.edu/prism/1084/thumbnail.jp

American Stalinism and anti-Stalinism

https://stars.library.ucf.edu/prism/1457/thumbnail.jp

The end of the Comintern

https://stars.library.ucf.edu/prism/1822/thumbnail.jp

A GPU-accelerated finite-difference time-domain scheme for electromagnetic wave interaction with plasma

A GPU-accelerated Finite-Difference Time-Domain (FDTD) scheme for the simulation of radio-frequency (RF) wave propagation in a dynamic, magnetized plasma is presented. This work builds on well-established FDTD techniques with the inclusion of new time advancement equations for the plasma fluid density and temperature. The resulting FDTD formulation is suitable for the simulation of the time-dependent behaviour of an ionospheric plasma due to interaction with an RF wave and the excitation of plasma waves and instabilities. The stability criteria and the dependence of accuracy on the choice of simulation parameters are analyzed and found to depend on the choice of simulation grid parameters. It is demonstrated that accelerating the FDTD code using GPU technology yields significantly higher performance, with a dual-GPU implementation achieving a rate of node update almost two orders of magnitude faster than a serial implementation. Optimization techniques such as memory coalescence are demonstrated to have a significant effect on code performance. The results of numerical tests performed to validate the FDTD scheme are presented, with a good agreement achieved when the simulation results are compared to both the predictions of plasma theory and to the results of the Tech-X® VORPAL 4.2.2 software that was used as a benchmark

Two-dimensional numerical simulation of O-mode to Z-mode conversion in the ionosphere

Experiments in the illumination of the F region of the ionosphere via radio frequency waves polarized in the ordinary mode (O-mode) have revealed that the magnitude of artificial heating-induced effects depends strongly on the inclination angle of the pump beam, with a greater modification to the plasma observed when the heating beam is directed close to or along the magnetic zenith direction. Numerical simulations performed using a recently developed finite-difference time-domain (FDTD) code are used to investigate the contribution of the O-mode to Z-mode conversion process to this effect. The aspect angle dependence and angular size of the radio window for which conversion of an O-mode pump wave to the Z-mode occurs is simulated for a variety of plasma density profiles including 2-D linear gradients representative of large-scale plasma depletions, density-depleted plasma ducts, and periodic field-aligned irregularities. The angular shape of the conversion window is found to be strongly influenced by the background plasma profile. If the Z-mode wave is reflected, it can propagate back toward the O-mode reflection region leading to resonant enhancement of the electric field in this region. Simulation results presented in this paper demonstrate that this process can make a significant contribution to the magnitude of electron density depletion and temperature enhancement around the resonance height and contributes to a strong dependence of the magnitude of plasma perturbation with the direction of the pump wave