Abstract: In a photocatalyst which is obtained by adding a co-catalyst to semiconductor particles containing strontium titanate and which causes a water decomposition reaction in which water molecules are decomposed into oxygen molecules and hydrogen molecules according to light emission, the semiconductor particles are doped with barium or additionally with scandium. A method of synthesizing a semiconductor for the photocatalyst includes a process of synthesizing semiconductor particles containing strontium titanate doped with barium by mixing barium titanate or additionally with scandium oxide into strontium chloride or mixing strontium titanate or additionally scandium oxide into strontium chloride and barium chloride and performing firing.

Abstract: The power system stabilizer is provided at an individual power system to be separated due to an accident cutting off a link line which interconnects a number of power systems to form a large-scale power system. The power systems include power stations such as power plants and transformer substations. A simplified arithmetic processing unit of the stabilizer performs an arithmetic processing by a simple linear equation using an output frequency of a representative power station belonging to the separated power system immediately after the accident has been cleared, so that a total load drop of the separated power system can be assumed. Based on the assumption amount, balance control of demand and supply in the separated system is made.