The retentivity of shape in uniaxial compression of polycarbonate resin when processing in the cold and warm processing temperature range was investigated experimentally. Iupilon, a polycarbonate resin manufactured by the solvent process, was used as the sample. Strain recovery of test specimens, which were processed by compression at various temperatures, was measured after free annealing by raising the temperature gradually to a temperature higher than the processing temperature. Polycarbonate has superior processability in the vicinity of room temperature and has good strain-freezing properties at temperatures below the glass transition temperature; however, strain is recovered completely at temperatures above the glass transition point. A new Erichsen testing apparatus was developed for measuring the temperature dependence of processability of sheet in the cold and warm temperature range. A punch is pushed into the sheet whose temperature has been made uniform in a constant temperature apparatus at a fixed stroke speed; the Erichsen depth at fracture at the various temperatures is measured. Results indicated that processability of polycarbonate sheet (thickness, 1 mm) improves gradually with temperature rise as high as the glass transition point. Experiments on strain recovery of an Erichsen test specimen were carried out in the same manner as in the case of uniaxial compression. The results for combined stresses, such as in Erichsen bulging, were similar to those of uniaxial compression. An attempt is being made to utilize such Erichsen bulging test specimens for environmental stress cracking tests of polycarbonate.

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pendence of the processing ability of sheet plastics in relation to the cold and warm processing of the polymer. Sheet specimen was penetrated by a solid punch at constant rate of stroke at various temperatures and the penetration depth at fracture was measured. The processing ability of polycarbonate sheet (1mm thick) was gradually improved as the increase of the temperature up to the glass transition temperature.The strain recoverey in the Erichsen test was examined in the same way as the uniaxial compression test, and a well parallelism between the results obtained under a combined stress such as the Erichsen bulging and those under an uniaxial compression as the above was found.be available for the environmental stress cracking test of the polymer.

Recently the deregulation of electric power industly has progressed in the world. In Japan the electric power industry law was revised in 1995, and competition in the power generation market has started. Moreover, the retail wheeling to l q e customers has begun from March 2000. In the circumstances it is more important to know how to secure supply reliability from the viewpoint of system operation.In this paper, we a s m e that there exist Power Producers and Suppliers (PPSs) and Indepmdmt System Operators (ISOs) of different companies in the future. Firstly, we deal with a PPS which aims at stable supply, on behalf ofcustomers whom he has bilateral contracts with and provides baekup supplies between PPSs or behveen PPSs and transmission owners for PPS generator tmubles. Secondly we deal with an IS0 that has responsibility for stable supply, and provides a backup supply between PPSs and uansmission owners for transmission line troubles. And we investigate how the control outputs are influenced by the way of backup contracts with other PPSs and transmission owners for anticipated troubles.

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