Kohzuki Y.,Oshima National College of Maritime Technology
Crystal Research and Technology | Year: 2010
It was investigated from (L0 /L)2 versus φ0 curve that the Friedel relation between the effective stress and the average length of dislocation segments, L, is appropriate for the interaction between a dislocation and the monovalent anion in various alkali halides single crystals (NaCl: Br̄, NaBr: Cl̄ or Ī, KCl: Br̄ or Ī, and RbCl: Br̄ or Ī). Here, L0 represents the average spacing of monovalent anions on a slip plane and φ0 is the bending angle at which the dislocation breaks away from the anion at the temperature of 0 K. This is because the anions are the weak obstacles such as impede the dislocation at φ0 above about 150 degrees, where the Friedel relation agrees with the Fleischer one (L 02 = L2(π-φ0)/2). Furthermore, the values of (L/ L0) were found to be within 4.05 to 5.87 for the crystals. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA.
Sugino T.,Oshima National College of Maritime Technology |
Yamane Y.,Hiroshima University
Key Engineering Materials | Year: 2015
Gloss of a metal surface is an important aspect for product quality evaluation. Evaluating the specular reflection is almost the same as evaluating the gloss. We propose a method that uses patterned area illumination to evaluate specular reflection. In specular reflection, the angle of incidence equals the angle of reflection. Consequently, when light (ray) of the area illumination, which has a striped pattern, are projected on a glossy metal surface, a striped pattern forms on the reflected image as a mirror-like reflection, and the sharpness of the striped pattern of the image provides information about the specular reflection on the surface. This characteristic is applied to a metal with a hairline surface finish. A hairline surface presents different glossiness at different viewpoints. When the direction of the striped pattern of illumination is changed, the sharpness of striped pattern on the reflected image varies owing to the surface roughness of the hairline finish. Therefore, we can evaluate the glossiness in various directions by rotating the pattern. The relationships between gloss evaluation value and surface roughness were indicated in our study. We tried the reproduction of the gloss evaluation by ray tracing to obtain the more detailed relationships between them. Ray tracing is a technique to generate an image in computer graphics. The approximate reproduction of gloss evaluation was obtained by the simulation. © (2015) Trans Tech Publications, Switzerland.
Takahashi K.,Oshima National College of Maritime Technology
Journal of the Vacuum Society of Japan | Year: 2014
Removal of small glass spheres on a Si substrate by using adhesion forces between particles and dielectric films was investigated. An upper Si electrode and a dielectric film such as that of polyethylene or polyvinylchloride were placed on a lower Si electrode to which small glass spheres were adhered, and a high voltage was applied to the two Si electrodes for 60 s. The glass spheres had a diameter of 2-20 mm and were adhered to the dielectric film; about 40-50% of the spheres were removed from the Si substrate in the first iteration of a removal process. The removal process was repeated several times, and a high removal rate of about 80% was obtained after the fifth iteration. This implies that the largest glass spheres were removed in the first iteration, and smaller ones were removed in subsequent iterations. The dependence of the particle removal rate on the particle size was evaluated as the ratio of the adhesive force between the particle and film and that between the particle and substrate. Further, it was found that the particle size decreases with the removal rate. This result was in agreement with the experimental result.
Kohzuki Y.,Oshima National College of Maritime Technology
Philosophical Magazine | Year: 2010
The Friedel relation between the effective stress and the average length of dislocation segments agrees with the Fleischer relation ([image omitted]) in the L0/L versus 0 curve within 150 0 180, where L0 is the average spacing of impurities on a slip plane, L is the impurities along a dislocation and 0 is the angle at which the dislocation embraces the impurity at a temperature of 0 K. Therefore, it was considered that the Friedel relation is suitable for impurity obstacles that impede the dislocation above 0 of about 150 during steady and plastic deformation. In addition, it was confirmed from the value of 0 that the Friedel relation is appropriate for the interaction between a dislocation and the impurity in alkali halides doped with monovalent impurities. This is based on the data obtained by strain-rate cycling tests associated with ultrasonic oscillation at 80 to 300 K.© 2010 Taylor & Francis.
Ichibakase T.,Oshima National College of Maritime Technology
Electronics and Communications in Japan | Year: 2011
La0.5Sr0.5CoO3 was employed as a cathode for the first time when plasma display panels were used on handheld personal computers. It has favorable sputtering resistance and stable discharge characteristics in gases. A cathode made from La0.5Sr 0.5CoO3 has unique electrical characteristics in the period of continuous discharge. Its discharge voltage and luminance shift during an extended discharge, and the discharge voltage continues to increase in the later period of the continuous discharge. The discharge and luminescence area shift of the La0.5Sr0.5Co03 were investigated by an analysis of a DC plasma panel made as a prototype. It is assumed that the discharge voltage and luminance shift were caused by the discharge and luminance area shift of the cathode surface, and that the current density shift was caused by discharge area constriction in the later periods of continuous discharge. In order to ascertain the mechanism, the discharge and luminance area shift process of the cathode surface were examined using a model. © 2010 Wiley Periodicals, Inc.