As a result of a revision of the JIS system, the application of the hot wire method for determining thermal conductivity has been expanded from heat-insulating bricks to refractories with higher heat conductivity. In this regard, focusing on magnesia bricks, which are used in the safety lining of converters and a wide variety of other applications, the authors studied the possibility of applying the non-stationary hot wire method in the determination of thermal conductivity up to the high-temperature range by using straight brick specimens. To perform measurements on magnesia bricks, whose thermal conductivity is higher than that of heat-insulating bricks, a set of measurement equipment including a highcapacity electric furnace was constructed, and as a result, it was possible to confirm the linear relationship between the increase in temperature of the hot wire and the logarithm of time log t by using straight brick specimens. It is possible to determine the thermal conductivity accurately by identifying the critical point where the À log t relationship ceases to be linear and calculating the thermal conductivity of the target material on the basis of the linear relationship.

Phase relations for the Al 2 O 3 -CaO-SrO ternary oxide system were clarified. This ternary system has a high liquidus temperature in most compositions and contained many types of solid solutions with a wide composition range. Hence, it was difficult to predict the precise phase diagrams by using conventional techniques such as chemical equilibration method. In fact, the phase diagram reported formerly contains a considerable amount of prediction and surmise and is far from satisfaction. In the present study, an in-situ observation at increasing temperatures was performed using a high temperature observational system that included a confocal scanning laser microscope (CSLM) in combination with an infrared image furnace as a heating device. As a result, definite images of the samples during melting were obtained, and the advantages of this method for the measurement of this type of ternary oxide system were confirmed. Further, a more appropriate ternary phase diagram and its 1973 K isothermal cross section were predicted.

This paper presents a practical method of solving the unit commitment problem, using a Genetic Algorithm and the Lagrangian Relaxation Method. This method utilizes the advantages of both the Genetic Algorithm and the Lagrangian Relaxation Method. Moreover, the introduction of heuristics simplifes genetic string manipulations which improve computation efficiency. Numerical results have shown that the method is effective in solving the practical unit commitment problem.

In this report, the trends in refractories technologies for iron and steel production at Nippon Steel Corporation in the last few decades are outlined. Amid dramatic changes in crude steel production accompanying increased ratios in higher quality of steel and sophisticated refining methods, in in our refractory ceramics R&D Div., actual machines have been realized by practicing developed outcomes with technologies for every production process relating to: refractory material quality, furnace building or execution, reparation, diagnosis, demolition, and recycling. Thus, continuing reduction in the unit consumption of refractories has been steadily performed. Additionally, technical issues are reduced to further enhance and maintain our international competitiveness in refractories technologies.

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