Study of the behavior of matter at temperatures below −200 C. The use of the liquefied gases oxygen, nitrogen, and hydrogen at approximately −260 C is standard industrial practice. Examples: Use of liquid nitrogen for quick-freezing of foods and of liquid oxygen in steel production. Some electronic devices and specialized instruments, such as the cryogenic gyro, operate at liquid-helium temperature (approximately 4 K). Many lasers and computer circuits require low temperature. Original research in this field was carried out by W. F. Giauque in the U.S. and by Kamerlingh-Onnes in Holland.See Superconductivity.