ASCA Observation of the Low-Luminosity Seyfert 1.5 Galaxy NGC 5033

We present the results of an ASCA observation of the low-luminosity Seyfert 1.5 galaxy NGC 5033. A point-like X-ray source with a luminosity of 2.3x10^{41} erg s^{-1} in the 2--10 keV band (at 18.7 Mpc; Tully 1988, AAA045.002.054) was detected at the nucleus. The X-ray light curve shows variability on a timescale of ~10^4 s with an amplitude of ~20%. The X-ray continuum is represented by a weakly absorbed (N_H~9x10^{20} {cm^{-2}) power-law with a photon index of 1.72+/-0.04, which is quite similar to Seyfert 1 galaxies with higher luminosities. A Fe Kalpha emission line is detected at 6.40^{+0.08}_{-0.06} keV (redshift corrected) and the equivalent width is 290+/-100 eV. The line width is unresolved. The narrower line width and larger equivalent width compared to Seyfert 1s imply that fluorescent Fe Kalpha emission from matter further out from the center than the accretion disk significantly contributes to the observed Fe Kalpha line. We suggest that fluorescent Fe Kalpha emission from the putative torus contributes to the observed Fe Kalpha line.Comment: 17 pages, To appear in PASJ, Vol. 51, No.

Computation accuracies of boundary element method and finite element method in transient eddy current analysis

The computation accuracies of the boundary-element method (BEM) and finite-element method (FEM) in transient eddy-current problems are compared by using a slot-embedded conductor model and a diffusion model that can be solved theoretically. For computing the vector potential or magnetic flux density it is shown that larger time-step width can be chosen in the BEM than in the FEM method for the same accuracy </p

Computaton of 3-dimensional Eddy current problems by using boundary element method

The boundary element method for computing 3-dimensional eddy current distributions is presented. This method is based on Vector Green's Theorem, and unknown electric field vectors and magnetic flux density vectors are assumed on the boundaries of two materials, and unknown electric field vectors are assumed in the conductor regions. After determining these unknown vectors, 3-dimensional eddy current distributions in the conductors are computed. The computation results of a conducting sphere model by this method were examined in contrast to those of a coupled circuit model. </p

The optimum design of electrode and insulator contours by nonlinear programming using the surface charge simulation method

A new method is presented for optimizing electrode and insulator contours. The contours are modified by using the iteration methods of nonlinear programming until the desired electric field distribution is obtained. The Gauss-Newton, quasi-Newton, conjugate gradient, or steepest descent method is used for the iteration. The electric-field distributions are computed by means of the surface charge simulation method. It is shown that the Gauss-Newton method gives very fast convergence </p

Techniques for boundary element analysis of three-dimensional eddy current distribution

An analysis of three-dimensional eddy-current distribution by a boundary-element method using field vector variables is described. A triangular element is used as a boundary element. The electric field vector and magnetic flux density vector are defined as the unknown vectors and are assumed to be constant on each triangular element. For forming simultaneous equations, the computation point on the triangular element is set at the null point, where the triangular element itself does not induce tangential components of the electric field and the magnetic flux density </p

An analysis of 3-dimensional magnetic field distributions in a small-sized synchronous motor with a permanent magnet rotor

This paper describes an analysis of 3- dimensional magnetic field distributions in a small-sized synchronous motor with a permanent magnet rotor and a simulation of the rotor behavior. Here, the concept of a surface magnetic charge is introduced, and then the magnetic field distributions are computed by using the integral equation method. Next, the rotor displacement is computed by using Newmark's &#946;-parameter method. By the use of these techniques, simulation of the rotor behavior is performed. The results of the simulation are examined in contrast to those of the experiments. </p

Computation of three-dimensional electromagnetic field in the eddy-current testing of steel pipes

The computation of three-dimensional electromagnetic field distributions in the eddy-current testing for holes in steel pipes is described. A boundary element method with vector variables was used to compute the eddy-current and magnetic-flux-density distributions. Computed and experimental results for the magnetic flux density on the inner surface are compared, and the mechanism of defect detection in steel pipes is clarified </p

Eddy current and deflection analyses of a thin plate in time-changing magnetic field

Eddy current and deflection analysis of a thin-plate model in a time-changing magnetic field is described. The model is solved as a coupled problem in which the time-changing magnetic field induces eddy currents and the eddy currents cause deflection of the thin plate by the Lorentz force. The eddy current analysis and deflection analysis are performed by an integro-differential method using a current vector potential and a structural finite element method using beam elements, respectively. The formulations of the motional electromotive force and the Lorentz force for the thin-plate model are presented. In addition, the applicability of the proposed method is verified by using a cantilevered-beam model </p

X-ray scattering from crystalline SiO2 in the thermal oxide layers on vicinal Si(111) surfaces

Shimura, T., Misaki, H. & Umeno, M. (1996). Acta Cryst. A52, C465, https://doi.org/10.1107/S0108767396080932

COMPUTATION OF THREE-DIMENSIONAL ELECTRIC FIELD PROBLEMS BY A BOUNDARY INTEGRAL METHOD AND ITS APPLICATION TO INSULATION DESIGN

This paper describes a boundary integral method for computation of three-dimensional electric field distribution. In the boundary integral method, the surfaces of electrodes and insulators are divided into curved surface elements because the use of the curved surface elements provides a good approximation of the contours of the electrodes and insulators. Furthermore, the boundary integral method is applied to optimum design of electrode and insulator shapes