In Japanese stee lworks , hot metal is now produced by scrap melting process . With this process removal of sulp hur is very much hand icapped because of very high sulphur levels (0.04 to 0.09 pet by weight) and relat ively low tapping temperatures (1623 to 1723 K). In order to overcome such disadvantages, the authors explored on the phase diagrams of {CaO-Si0 2-AI203-MgO} slags, and this research revealed that those slags at 35 wt%-A1 203 would be good candidates as reage nts for the removal of sulphur from high sulphur hot metal at relatively low temperatures. For better understanding of the thermodynamic properties of the cand idate slags, in this study, activities of FexO were determ ined by using solid-state electrochemical cells incorporating MgO-stabilized zirconia and Mo + Mo0 2 reference electrode.Keywords: hot metal , scrap melt ing, high sulphur contents, removal of sulphur, thermodynam ic properties of slag , sol id-state electrochem ical cells.

Abstract. We present first results from a search for quasi-periodic (QP) radar echoes in the American sector. These echoes, which are produced by underdense backscatter from field-aligned irregularities in nighttime midlatitude sporadic E (Es), have been observed in the Asian sector but never before at other longitudes.Using radar data collected during the summer in 1998 from Stanford, California, we show that QP echoes can indeed be detected in the American sector and that they resemble those found in central and southern Japan. We then show that the invariance of a feature in the pattern of QP echoes, which persisted for five hours on 3 August 1998, raises questions regarding the existing models for QP echoes.

Abstract. This paper describes results from simultaneous measurements of mid-latitude irregularities by a sounding rocket and a Doppler radar. The experiment was conducted on August 26, 1996 as part of the SEEK (Sporadic-E Experiment over Kyushu) campaign in Japan. Electric field observed with a doubleprobe sensor on the rocket showed very large fluctuations of 4-10 mV/m where irregularity echoes were quite intense. Doppler velocities observed with the radar agreed well with the electric fields. We estimated growth rates of the gradient-drift instability, which showed positive values around the major sporadic-E layer. It was found that, within intense irregularity region with quasi-periodic structures, there were large polarization electric fields that was likely to be associated with spatial structure of the sporadic-E layer.