Abstract: A defrost control apparatus and method for controlling the defrosting of a cooling coil of a refrigerator by estimating a postpone defrost time to postpone the defrosting of the cooling coil in accordance with fuzzy logic reasoning. The fuzzy logic reasoning uses the total number of times a door on the refrigerator is opened and an outside temperature value related to the outside temperature as input variables. The fuzzy logic estimate is produced at predetermined time intervals after a compressor of the refrigerator has operated a predetermined time since the last defrosting. The defrost control apparatus counts the total refrigerator operating time period after the compressor has operated the predetermined time. The defrost control apparatus starts to defrost the cooling coil when the total refrigerator operating time period exceeds the postpone defrost time.

Abstract: In a thermoelectric refrigeration material with thermoelectric conversion characteristic, in order to improve crystallinity of a system of bismuth-antimony (Bi-Sb) and thereby to improve the figure of merit Z, bismuth (Bi), antimony (Sb) and silicon monoxide (SiO) are deposited on a substrate at a predetermined rate in a thermally nonequilibrium state by an ICB method so that a thin film crystal having a granular structure including crystal grains of around one micron is obtained. Consequently, the figure of merit Z can be improved by selectively varying the thermal conductivity K which largely depends upon the crystallinity and which is one of elements of the figure of merit Z determining the thermal conversion coefficiency.