Two group of rubber have been renewed after the begining of service of the vibration damper on the main engine. The first renewal was after 5 years and 8 months from the installation and the second after 7 and half years from the first. The rubber used now is the third group over 2 years from the second. It was found out that the estimated values of shaft center with calculating the difference of the rubber-shrinkage correspond with the measured ones. So, the detailed investigation could be carried out for the variation of shaft center by the compound deformation due to heat, elasticity and plasticity and the creep of the rubber on each of group for long time. It happened sometimes that the variation of shaft center became about 1.0 mm with the difference of the environmental temperature, e.g. such as that of before starting and just after stopping engine. The value is the limit to the engine. Then the early large creep reduce like gentle slope after 10-12 months from setting new one

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This paper describes a novel steam super-heater system which consists of sheath heater and induction heating unit. The structure of hybrid heater system is introduced as compact system for its portable use.The characteristic of electrical equivalent circuit of induction heating load as the temperature of heat exchanger rises is clarified.
A complex resonant zero current switching (ZCS) high frequency inverter is proposed as the high frequency power supply. The optimum circuit parameters such as inductance ratio and capacitance ratio are investigated in connection with ZCS operation region.
On the basis of these investigations, the complex resonant ZCS high frequency inverter is designed. The steam super-heater system is successfully examined and superheated steam of 200°C is generated in 30 second from starting condition. The usefulness of the
high frequency power supply is verified experimentally as high efficiency of 96% on power conversion.

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To clarify the proper dilution ratio, new dilution system was designed. The sampling line that was heated by flexible heater was inserted to dilution tunnel horizontally. And the tip of the line was designed as double pipe so that exhaust gas may not be cooled by dilution air. The examinations were carried out to change the dilution ratio was set from 4 to 30 by using old and new dilution systems.
Results obtained from the examinations are as follows.
(1) Measured PM decrease when a dilution ratio is enlarged.
(2) The decrease ratio become about 1/4 by using the new system.
(3) The most suitable value of the dilution ratio is around 5.

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[in Japanese]

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