Investigation of direct integration for nonlinear finite element equations of motion by the modified central difference method

The investigation of stability and precision of the previously proposed implicit scheme of direct integration for the finite element equations of motion is presented. The scheme parameter values that ensure its unconditional stability in the nonlinear problems are determined and comparison with existing procedures is given.     

Pull-In Time and Range of Any Order Generalized PLL

The general pull-in range and pull-in time expressions are derived versus the relevant system parameters and the initial detuning for any order loop with any type of phase detector by the quasistationary approach. Even though the pull-in time expression becomes more accurate as the loop's order becomes larger, it is correct also for second-and third-order loops provided that the initial detuning, supposed large, is approaching the pull-in range value.     

Waves in space plasmas: Highlights of a Conference held in Hawaii, 7–11 February 1983

The Conference was called to bring together investigators of magnetospheric plasma waves having frequencies from VLF whistlers and emissions down through ELF and ULF to Pc5 long period pulsations. The emphasis was on the physics and techniques underlying the entire frequency range. Topics included wave electron interactions and electron precipitation, ray tracing and other methods to track down sources of VLF and ULF waves, VLF-ULF relationships, heavy ion effects in ULF propagation, and long period ULF waves.     

The effect of the longitudinal propagating waves on the electron acceleration in the reconnecting current sheet

Based upon the most efficient electron acceleration near the midplane of 3D non-neutral driven reconnecting current sheet (RCS) and the electrostatic wave excitation by the drift Maxwellian distribution of electrons in Vlasov simulation, we assume that the electrostatic waves mainly propagate opposite to the reconnecting electric field and investigated how these waves affect the electron acceleration. The main results are: (1) when the electron’s velocity equals to the phase speed of the waves, they will be trapped and have the different accelerating characteristics from the untrapped electrons through solving the momentum equations of electrons analytically; (2) the test particle simulations further prove that the number of the energetic electrons decreases with the increasing intensity of unstable waves, and the distribution of the energetic electrons takes on the double power-law.     

Determination of the Turbulent Diffusion Coefficient in the Plasma Sheet Using the Project INTERBALL Data

The results of an analysis of velocity fluctuations in the plasma sheet of the Earth's magnetotail measured onboard INTERBALL Tail Probe satellite are presented. The hodographs of the velocity in directions (Y, Z) and correlation functions are presented for a number of passages when the satellite was in the plasma sheet for a long time. The turbulent diffusion coefficients are calculated. A comparison of the obtained diffusion coefficients with those predicted theoretically in [1] is carried out. It is shown that the results of observations confirm theoretical predictions.     

A 10 kW DC-DC converter using IGBTs with active snubbers

This full bridge DC-DC converter employs zero voltage switching (ZVS) on one leg and zero current switching (ZCS) on the other. This technique produces exceptionally low insulated-gate bipolar transistor (IGBT) switching losses through the use of an active snubber that recycles energy back to the source. Experimental results are presented for a 10-kW, 20-kHz converter     

Wireless sensor networks for planetary exploration: Experimental assessment of communication and deployment

Planetary surface exploration is an appealing application of wireless sensor networks that has been investigated in recent years by the space community, including the European Space Agency. The idea is to deploy a number of self-organizing sensor nodes forming a wireless networked architecture to provide a distributed instrument for the study and exploration of a planetary body. To explore this concept, ESA has funded the research project RF Wireless for Planetary Exploration (RF-WIPE), carried out by GMV, SUPSI and UPM. The purpose of RF-WIPE was to simulate and prototype a wireless sensor network in order to assess the potential and limitations of the technology for the purposes of planetary exploration.