Colorado Springs, Colorado, spectacularly located at the foot of Pike's Peak, was the site of the joint 1983 Cryogenic Engineer­ ing Conference - International Cryogenic Materials Conference. Over 300 papers were presented at the two conferences on a variety of cryogenic science and engineering topics. Volume 29 of Advances in Cryogenic Engineering contains 116 of the papers presented at the 1983 Cryogenic Engineering Confer­ ence. Each paper was comprehensively peer reviewed to maintain the international reputation of the series as the premier archival medium in the field of cryotechnology. I would like to thank both authors and reviewers for their assistance in the preparation of this volume. R. W. Fast, Editor xvii DEDICATION The cryogenic engineering community was saddened to learn of the death of A. Clark Leonard of the Royal Military College of Canada, Kingston, Ontario, on November 24, 1983. Professor Leonard was born in Prince Albert, Saskatchewan, Canada, in February, 1922. Following service in the RCAF during World War II he received his B.M.E. degree at the University of Saskatchewan. While serving with the Canadian forces in Korea, he was awarded membership in the Order of the British Empire. He received his M.S. and Ph.D. degrees in Mechanical Engineering at the University of Michigan.