Abstract: Method for manufacturing a plate boehmite and a plate alumina having high catalytic activity. The plate boehmite is prepared by subjecting at least one kind of an alkaline earth metal compound, which is selected from calcium, strontium and barium, and aluminum hydroxide to pressurization and heating at 150 to 300° C. in the presence of water. The resulting reaction product is treated with an acid to remove the residual alkaline earth metal compound contained in the product, followed by rinsing with water. The resulting plate boehmite is subjected to calcination at 450 to 1500° C. Thus, a plate alumina comprising a mixture of &thgr;-alumina and &dgr;-alumina as a major component is prepared.

Abstract: A thermal transfer machine comprising a freely rotatable belt attachment roller onto which an endless belt can be removably attached with the surface to be imprinted facing outwardly, a freely rotatable thermal roller placed so as to be movable toward and away from said belt attachment roller, a pair of support arms placed parallel to each other across an open space so that said thermal roller is positioned between them, and a marking paper support which has securing fixtures for stretching the marking paper across the space between the support arms and which is capable of moving in a reciprocating motion in the front-to-back direction of the thermal roller.