Electrical resistivity measurements were performed on Fe-doped bulk silicon carbide specimens in the 5~300 K temperature range. The Si_1−xFe_xC (x = 0.02, 0.03, 0.04) specimens have zincblende structure and exhibited diluted ferromagnetic properties. The electrical resistivities of the specimens were in the 10⁰~10¹ Ωcm range, decreasing with increasing temperature. The resistivity decreased with increasing Fe composition in the whole temperature range with more decrease as the temperature is lowered. The temperature characteristics of the resistivity were explained in terms of the polaronic hopping conduction model.

Core losses of dc-biased Fe-Si-Al and Fe-Ni cores were measured. Changes of shapes and amplitude of ac loops, and permeability were attributed from the incremental permeability derived from dc loops. Core loss decreased with increasing dc field and then increased abruptly regardless of frequency in the cores with high permeability. It seemed that the decrease of the core loss with increasing dc field was attributed from decrease of dc hysteresis loss. Increase of the loss was seemed to be attributed from increase of amplitude of ac field which was also due to decrease of incremental permeability.

A fractional-slot permanent magnet synchronous motor under 180 degree sinusoidal current can be adopted for the electric power steering system of hybrid and electric vehicles. This motor has various stator winding methods such as double-layer and single-layer for its purpose. In this paper, we investigate the iron losses characteristic of the permanent magnet synchronous motor according to the various winding methods. To get the accurate hysteresis and eddy-current losses, we consider the time harmonics of the instantaneous flux density using finite element method. From the analysis results, we know that the most of the iron losses are generated in the stator and the stator teeth shoe part has the highest iron losses density because of its rotating magnetic flux. Under the light and the rated load, the single-layer has less iron losses compared to the double-layer. However, as the load increases, the iron losses in the single-layer rapidly become larger. This is because the magnetic circuits are saturated.

Single-phase SRM is a low cost motor with a simple magnetic structure and minimum power switches. But in the application of single-phase SRM, it has been limited to self-starting problem. In this paper, new single-phase SRM with a segment rotor is presented and analyzed. The segmental rotor type SRM has advantages such as shortening the magnetic path and reducing windage loss. In order to solve the starting problem for a single-phase SRM, a strategy of starting by changing the shape of the segment rotor with a circular hole has been proposed. This new single-phase SRM was analyzed by FLUX2D, a finite element analysis program.

In this paper, the implications of implementing a dielectric or magnetic body with a dipole model are discussed. The concept of bound charge canceled inside is basically a bound charge projected onto the surface, and the force on it can not be regarded as the density of the electromagnetic force. Projected bound charge is only effective when affecting the field outside the material and calculating the total electromagnetic force. It is shown that the introduction of virtual air-gap along with the projected bound charge can calculate the electromagnetic volumetric density.

The antiferromagnetic IrMn based GMR-SV (giant magnetoresistance-spin valve) multilayer on the high-Tc superconductor YBCO film fabricated by using ion beam deposition and dc magnetron sputtering systems. The hybrid multilayer structure performed with the typical GMR-SV film and the superconducting YBCO film was compared two different magnetoresistance curves, which are measured at a room and a liquid nitrogen temperatures below the critical temperature. The exchange biased coupling field (H_ex), coercivity (H_c), magnetoresistance ratio (MR (%)) for the pure GMR-SV multilayer measured at 77 K are enhanced to the increment values of 80 Oe, 43 Oe, and 6.6% more than those measured at room temperature, respectively. In case of YBCO/GMR-SV mulitlayer, the H_ex, H_c, and MR (%) are 410 Oe, 240 Oe, −4.6% more than those measured at 77 K, respectively. The phenomenon having a negative MR (%) below the critical temperature is explained the current in plane tunneling (CIPT) effect when the resistance of the middle G layer between the high-temperature superconductor YBCO and the GMR-SV multilayer reaches a level comparable to the plane resistance of the upper metal layer.

Eddy current technology has been used widely in the in-service inspection identify the corrosion for the safe and economical management of these fleets. Although the detection of corrosion by ultrasonic and eddy currents is not inherently difficult, there are problems with identification and characterization for multi-layer structure. Pulsed eddy current (PEC) is redeem these limitation of eddy current technology. PEC technology such as basic theory, system design and application was review in this paper. The PEC system was designed and manufactured in order to detect the local wall thinning such as corrosion under insulation (CUI) and flaw accelerated corrosion (FAC). Local wall thinning is a point of concern in almost all steel structures such as pipe lines covered with a thermal insulator made up of materials with low thermal conductivity (fiberglass or mineral wool); hence, Non Destructive Technique (NDT) methods that are capable of detecting the wall thinning and defects without removing the insulation are necessary. In this study we developed a Pulsed Eddy Current (PEC) system to detect the wall thinning of Ferro magnetic steel pipes covered with fiber glass thermal insulator and shielded with Aluminum plate. The PEC system can detect the wall thinning and 20 % local defect under the 50 mm thickness insulation and 0.5 mm Al cladding, and the output signal showed linear relation with tube wall thickness.