Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 28 2 1994 Chemical States of Fluorine Atoms and Laser-Induced Crystallization in rf-Sputtered Thin Films of Amorphous Lead Fluorosilicate 77 84 EN Akiyoshi Osaka Yoshinari Miura 10.18926/15464 Amorphous films of lead oxyfluorosilicate were prepared with a rf-sputtering technique, and the distribution profiles of the component elements and chemical states of the fluoride ions were analyzed with an X-ray photoelectron spectrometer. Si atoms with an expanded coordination, O(4)Si-F, were present near the surface, and O(3)Si-F units were present in the deeper part of the films. Electrical resistance indicated transition to a conduction state for the films containing fluoride ions, while the films were crystallized to precipitate low quartz by the irradiation of He-Ne laser of 3 mW up to 1 sec. No potential conflict of interest relevant to this article was reported.

Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 28 2 1994 A Study on the Elasto-plastical Constitutive Equation for Unsaturated Soil 59 75 EN Makoto Nishigaki Iichiro Kohno 10.18926/15463 In this paper, first, an elasto-plastic consitituve equation for unsaturated soil was developed by considering of the basically behavior of unsaturated soil. Second, the results of a number of triaxial test and a set of rigid foundation model tests were simulated by using this constitutive equation, the agreement between observed and computed results was satisfactory and confirms the possibilities of this constitutive equation. No potential conflict of interest relevant to this article was reported.

Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 28 2 1994 Note on the Piezoelectric Constant of PbZrO(3)-PbTiO(3)(PZT) 53 58 EN Chieko Totsuji 10.18926/15461 One of the best known solid solution of perovskites is the PbTiO(3)-PbZrO(3) system which is usually abbreviated as PZT. In the phase diagram of this system, there is a drastic phase change from tetragonal to rhombohedral at the molar ratio around 50:50. The PZT crystals are widely used as a practical piezoelectric material because of its very strong piezoelectric effect near this morphotropic phase boundary. We try to explain this anomaly in piezoelectric constant by a phenomenological theory. No potential conflict of interest relevant to this article was reported.

Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 28 2 1994 Numerical Simulation of Quantum Systems -Dynamics of Electrons in Microstructures- 45 52 EN Hiroo Totsuji Seiji Hashimoto Shigetoshi Nara 10.18926/15460 Difficulties in simulating systems composed of classical and quantum particles lie in the treatment of the many-body interactions between quantum particles and the geometrical variety of configurations of classical particles. In order to overcome these difficulties, we have developed some numerical methods and applied them to simple cases. As for stationary states, the finite element method provides us with sufficient geometrical freedom. Combined with the Kohn-Sham equation based on the density functional theory, this method virtually satisfies our requirement. In order to investigate time-dependent phenomena, we apply the time-dependent Kohn-Sham equation. Adopting the finite difference method, we are able to follow the development of quantum many-body system. As an example, we estimate the effects of the potential height, the electric field, and many-body interactions in some transition processes in quantum wells coupled by a tunneling barrier. This example is important in itself in relation to semiconductor superlattices and also serves as a benchmark for quantum simulations, variety of geometry corresponding to that of classical particles. No potential conflict of interest relevant to this article was reported.

Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 28 2 1994 Collimation of Cerenkov-SHG Blue Light with a Parabolic Mirror 33 44 EN Ming Wang Anis Ahmed Osami Wada Ryuji Koga 10.18926/15458 Proposed here is a convenient optical system to collimate the crescent shaped blue laser beam radiated from a Cerenkov SHG in channel waveguide configuration. This collimation system is consisted of a parabolic mirror and has a very large tolerance to the mirror displacement. The anisotropy of the nonlinear crystal on which the waveguide is fabricated has been taken into account. The optimum mirror location is given to obtain a collimated blue laser beam with an aberration less than 0.07ƒÉ. By using an objective lens, the collimated beam can be focused down to a thin beam with the spot size less than 1ƒÊm. No potential conflict of interest relevant to this article was reported.

Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 28 2 1994 Cyclone Dust Collector with a Perforated Internal Rotating Cylinder 21 31 EN Kyoji Yamamoto 10.18926/15456 An experimental investigation has been made of the cyclone dust collector with a perforated internal rotating cylinder. The size of the rotating cylinder is of 0.5D, where D is the diameter of the cyclone body, and is the same size as the outlet tube. The dust collection efficiency as well as the pressure loss has been measured when the inlet flow speed is 9 ~ 21 m/s and the rotating speed of the cylinder is 37 ~ 63 m/s. The velocity and pressure distributions were also measured. It is found that the collection efficiency decreases and the pressure loss increases as the rotating speed increases. It is also shown that both the inward radial velocity and the upward vertical velocity become large as the rotating cylinder increases its speed. As a whole, the rotation of the internal cylinder makes worse performance of the cyclone dust collector. No potential conflict of interest relevant to this article was reported.

Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 28 2 1994 X-Ray Topographic Observation of Strain Generated by Thin Film (TiN) on Silicon Surface 13 20 EN Hisao Kusumoto Moritaka Hida Akira Sakakibara Norihide Nishida Yoshito Takemoto Masuo Yamada 10.18926/15453 The strain in Si substrate induced by locally ion-plated thin film of TiN was observed by X-ray topograph (Lang technique). Circular TiN film was deposited on one side of the Si surface. In all topographs the highest blackness attributed to kinematical diffraction effect occurred at the film edge. Rosette pattern with four-lobes was observed around the film. Blackness as a whole increased with the film thickness. Strain was observed in the depth direction of substrate by limited projection method. When the slit width was narrowed, the kinematical images disappeared, and white images appeared at the film edge. All the contrast disappeared when the TiN film was completely removed in boiling HNO(3). The strain induced by the film deposition was proved to be elastic. No potential conflict of interest relevant to this article was reported.

Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 28 2 1994 Clusters in Low-Concentrated Al-Mg Alloy 9 12 EN Akira Sakakibara Teruto Kanadani K. Nakagawa Y. Yokota 10.18926/15452 The state above the solubility temperature of GP zones of Al-3mass % Mg alloy, which has a tendency for precipitation and preprecipitation at low temperature, was studied by resistivity measurement. Homogenization treatment at high temperature reduced Mg atoms in the surface layer. After quenching from 623K, the specimen was annealed sequentially at various temperatures above the GP zone solvus. The stationary resistivity obtained in annealing at a temperature was the same irrespective of the starting state and increased with decreasing annealing temperature. No precipitation was observed in the annealing. The results are not in favor of the segregation of Mg atoms to the dislocation loops but of the short range clustering. No potential conflict of interest relevant to this article was reported.

Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 28 2 1994 Internal Structure and Phase Transformation of Ti-Mo Alloy Fine Particles 1 7 EN Yoshito Takemoto Akira Sakakibara Moritaka Hida 10.18926/15448 Fine particles of Ti-Mo alloy have been prepared by means of arc method, and investigated on internal structure and phase transformation using HR-TEM and EDS. Martensite phase was observed in a particle containing comparatively low concentration of Mo, and ƒÖ phase was also found to exist in a nearly 14 % M0 particle. The structure of the ƒÖ phase in the fine particle is expanded and remarkably unstable in comparison with the bulk sample, so that it has disappeared in a few seconds during TEM observation. Moreover, the ƒÀ structure of Ti-Mo particles has changed to the unusual fcc phase with irradiation of a strong electron beam. No potential conflict of interest relevant to this article was reported.