A catalyst able to overcome defects of an absorption reduction-type NOx purifying catalyst, such as poor NOx purifying capability at low temperatures and low SOx desorbing property, is provided. A distributor receives personal information regarding a referred customer from a sales representative over a world wide computer network. The late air injected between the top of the hearth and the inlet of the cyclone is used to increase the efficiency with which the cyclone collects the particles that reach the top of the hearth unburnt, and thus to increase the combustion efficiency of the system. The coating comprises a ceramic single or two oxide base layer disposed on the substrate surface; and a ceramic oxide reaction product material disposed on the base layer, the reaction product comprising the reaction product of the base layer with a ceramic single or two oxide overlay layer.