The polymeric materials, which have been generally considered to be good corrosion resistant material, are also degraded according to environments. The degradation behavior of polymeric materials can be classified into physical and chemical process. The later behavior in which molecular chain are cut chemically are called as corrosion. In this paper, the behavior, form and mechanism of corrosion of thermosetting resins used as matrix of GFRP (glass fiber reinforced plastics) under several solutions are mainly reviewed based on our experiments. The degradation behavior of GFRP are also mentioned briefly.
A neural network model for finding out of operational conditions for production of desired size crystal in a continious crystallizer with an actual heat exchange area of 3 m2 was discussed. The product crystal size is well correlated among evaporating rate, suspension density of crystal in crystallizer, composition of mother liquid, seed crystal size and seeding rate. The product crystal sizes estimated by neural network model and the measured values almost agreed within 10μm in the random operational conditions.
The control of product crystal size in an industrial crystallizer with an actual heat exchange area of 400 m2 is discussed with regard to application of a neural network model consisting of three explanatory variables: steam flow rate, suspension density of crystal and frequency of circulation pump. The most suitable learning number for the neural network model obtained by the Leave-one-out Cross Validation method was 50,000, and the mean estimated error of product crystal size was about 30μm. From these results, it is believed that the neural network model is accurate enough for practical use, and is effective for designing operational conditions for manufacturing products with the desired crystal size in industrial crystallization. A practical constructing method for a neural network model is proposed.
With reference to the sea water thermal source heat pump system introduced for supplying heat to the Seaside Momochi Area located in the western part of Fukuoka city, measures for improving the system's efficiency are described first, and then an evaluation of the performance and the energy saving effects of the system are presented. It has been confirmed that the coefficient of performance (COP) under heating and cooling operations of the system reaches 3.46 and 4.86, respectively and the energy saving factor reaches 26% and 47%, respectively.