Mössbauer spectra of hexagonal BaFe 12 O 19 single crystals were studied at various temperatures (4-300 K). It was found that the spin states in Fe atoms were parallel to the γ-ray's direction into a single crystal along the caxis. The location of the Fe ion in the 2b site is unusual in an oxide structure and has strong anisotropic lattice vibrations. Moreover, at room temperature, the zero absorption lines of the Fe ions at the 2b site were observed due to fast diffusion motion in a double well atomic potential. The two Fe ions of the single crystal mainly enter into the sites in the mirror plane of the trigonalbipyramidal structure.

This study analyses power generation system from ocean waves by using linear generator. A buoy is placed on the ocean surface and connected to the linear generator. Due to the movement of the buoy, the mover of the linear generator is reciprocated. The power is generated by movement of the mover. A converter system is needed for the power generation between the linear generator and the grid. For the study of the power generation system, a simulation model was made in MATLAB-Simulink. This paper aims at studying the converter system of wave generator and using when the converter system is designed.

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This paper deals with the performance analysis and estimation of the electrical parameters of a permanent magnet synchronous generator (PMSG) for hydrokinetic energy conversion applications using vortex induced vibration (VIV). The analytical solutions for the magnetic fields produced by permanent magnets (PMs) and stator winding currents are obtained using a 2D polar coordinate system and a magnetic vector potential. An analytical expression for the 2D permeance is also derived, which takes into account stator skew effects. Based on these magnetic field solutions and the 2D permeance function, electrical circuit parameters such as the backemf constant and the air-gap inductance are obtained analytically. The performances of the PMSG are investigated using the estimated electrical circuit parameters and an equivalent circuit (EC). All analytical results are validated extensively using 2D finite element (FE) analyses. Experimental measurements for parameters such as the back-emf and inductance are also presented to confirm the analyses.

Abstract. This paper describes ocean wave power generation by using permanent magnet linear synchronous generator. The preliminary analysis has shown that a linear generator enables substantial simplification of the mechanical system with respect to a dc generator case [1]. The linear motor has been adopted, taking into consideration the features of the incident waves and the behavior of the floating buoy. The floating buoy is placed on the ocean surface and connected to the generator. The wave energy is carried out from the movement of a buoy. An electrical conversion system is needed between the generator and the grid. For an analysis of the power system, the modeling of the linear generator and converter system was proceeded. This paper aims at studying the electrical part of the wave energy converter and study what impact the electrical system will have on the generator.