According to the results of a questionnaire in the Trends in International Mathematics and Science Study (TIMSS) conducted in 2011 by the International Association for the Evaluation of Educational Achievement (IEA), high school students in Japan do not realize the significance and usefulness of learning science. Many events on science education targeting high school students have been held in an attempt to solve this problem. At the events, various scientific experiments are introduced to attract the interest of students to science subjects or science technology. In this study, the taste sensor, which is used in the food industry and pharmaceutical industry, is considered as a science teaching material. We fabricated a new taste sensor for educational purposes that satisfies the requirements of safety and fabrication time for science teaching materials. In a basic experiment, the results correspond to the response of human taste, which also shows logarithmic changes. In an experiment demonstrating an application of the taste sensor, the results mean that the taste sensor fabricated for education can measure the intensity of saltiness and sourness in a beverage. Thus, it was indicated that the taste sensor fabricated for education is a useful science teaching material.

抄録全体を表示

A method to measure the refractive index of the ceramic layer of thermal barrier coating (TBC), based on the intensity ratio of the reflections of terahertz waves from the ceramic surface and a reference metal plate, is proposed. The method uses a variable aperture to change the relative proportions of specular reflection and scattering from the ceramic surface. The refractive index is calculated from the specular reflectivity, which is obtained from the intensity ratio when the field of view is extrapolated to zero. Measurement of a TBC specimen resulted in a refractive index of 4.7, which was in agreement with the refractive index of the ceramic material obtained by terahertz time domain reflectometry. In addition, the surface roughness of the ceramic surface was obtained based on the frequency characteristics of the reflections from the ceramic surface and a reference metal plate. A surface roughness of 14µm was obtained, which was in agreement with the microscopic observation result of a TBC specimen whose coating was applied in the same lot as the specimen used in the measurement.

抄録全体を表示

With the miniaturization of MEMS (micro electromechanical systems) devices, the insulation width and the separation between electrodes in such devices have been accordingly reduced. Consequently, electrical breakdown phenomenon across micrometer-scale gap is of great practical interest for insulation designing of miniaturized devices. In this paper, breakdown phenomenon under impulse voltage application across micro-meter scale gaps fabricated on SO wafers were observed.

抄録全体を表示