Foreword

We present here the Volume 57, No. 3 of the Memoirs of the Faculty of Engineering, Kyoto University, which is the last issue of its publication. The decision to discontinue the Memoirs was made by its Editorial Committee in April, 1995

Glass science and glass industry in Japan

In this paper, the history of the Japanese glass industry from the introduction of European glassware in the 16th century is presented first, and the current state of the glass industry, such as the change in number of workers and sales of glass products in recent years, is described next. Then, the research and development areas of industrial interest and the research topics in academic institutions are summarized

High temperature behavior of glass (M-8)

The twofold purpose of this experiment is to obtain data on the occurrence of flow in a viscous glass sphere in microgravity, and to confirm data obtained on Earth for volume-temperature relationships of glass. To do this, a cubic sample of glass laced with gold particles will be heated in the IMF. The sample's properties will be measured at high temperature, and the volume of the sample varied to measure the expansion coefficient. Movement of the gold particles, if any, will determine flow within the sample. The apparatus for this experiment is schematically shown and the photographs of the image furnace with samples before and after melting, respectively. In this apparatus, shape and size of the sample are observed by video camera and recorded by video recorder. The recorded images of the sample are schematically shown. Symbols A, B, and C denote low, intermediate, and high temperatures, respectively. From these images, the volume of the sample is estimated and the temperature dependence of the volume, is obtained. If there is agreement between the data collected in this experiment and data obtained on Earth, it would tend to verify Earth-collected data

Spin-Freezing Temperature of Some Oxide and Fluoride Glasses Containing Iron (III)

The magnetic transition observed in iron-containing oxide and fluoride glasses where antiferromagnetic interactions are dominant among the iron ions has been discussed on the basis of the superparamagnetic model. The theoretical approach based on the model proposed by Shtrikman and Wohlfarth has revealed that the spin-freezing temperature of the oxide and fluoride glasses increases with the increase of the average value of the superexchange interaction. This suggests that the spin-freezing temperature increases with the increase of the covalency of Fe-O or Fe-F bond when the content of the iron ions is identical. The relation between the spin-freezing temperature and the isomer shift value obtained experimentally for some oxide and fluoride glasses seems to support this expectation

Microstructure and magnetic character of terbium borate glass

Microstructure and magnetic character of 30 Tb2O3 · 70 B2O3 glass have been examined by means of high-resolution transmission electron microscopy and magnetization measurements. Although no trace of crystahine phases was observed in the electron diffraction pattern, the transmission electron micrograph revealed that there exist clusters, the size of which is about 1 nm, in the present glass. The magnetization measurements showed that this glass is paramagnetic at room temperature. However, the magnetization is high enough for the glass to adhere to a permanent magnet in the Nd-Fe-B system at room temperature

Developments of frequency comb microwave reflectometer for the interchange mode observations in LHD plasma

We have upgraded the multi-channel microwave reflectometer system which uses a frequency comb as a source and measure the distribution of the density fluctuation caused by magneto-hydro dynamics instability. The previous multi-channel system was composed of the Ka-band, and the U-band system has been developed. Currently, the U-band system has eight frequency channels, which are 43.0, 45.0, 47.0, 49.0, 51.0, 53.0, 55.0, and 57.0 GHz, in U-band. Before the installation to the Large Helical Device (LHD), several tests for understanding the system characteristics, which are the phase responsibility, the linearity of output signal, and others, have been carried out. The in situ calibration in LHD has been done for the cross reference. In the neutral beam injected plasma experiments, we can observe the density fluctuation of the interchange mode and obtain the radial distribution of fluctuation amplitude