Cryogenics, a term commonly used to refer to very low temperatures, had its beginning in the latter half of the last century when man learned, for the first time, how to cool objects to a temperature lower than had ever existed na tu rally on the face of the earth. The air we breathe was first liquefied in 1883 by a Polish scientist named Olszewski. Ten years later he and a British scientist, Sir James Dewar, liquefied hydrogen. Helium, the last of the so-caBed permanent gases, was finally liquefied by the Dutch physicist Kamerlingh Onnes in 1908. Thus, by the beginning of the twentieth century the door had been opened to astrange new world of experimentation in which aB substances, except liquid helium, are solids and where the absolute temperature is only a few microdegrees away. However, the point on the temperature scale at which refrigeration in the ordinary sense of the term ends and cryogenics begins has ne ver been weB defined. Most workers in the field have chosen to restrict cryogenics to a tem perature range below -150°C (123 K). This is a reasonable dividing line since the normal boiling points of the more permanent gases, such as helium, hydrogen, neon, nitrogen, oxygen, and air, lie below this temperature, while the more common refrigerants have boiling points that are above this temperature. Cryogenic engineering is concerned with the design and development of low-temperature systems and components.

Heat Transfer: Current Applications of Air Conditioning deals with problems and applications of air conditioning. The discussions are organized around non-stationary heat transfer through walls; study of confined rooms or enclosures; calculation of cooling loads; heat transfer with two-phase refrigerants; measurement of thermal conductivity and water vapour permeability of insulating materials; and tests on air handling equipment (room air-conditioners, induction or fan coil air-conditioners). This book is comprised of 60 chapters and begins with an assessment of the unit-system controversy in the United States and the quest for an ultimate resolution. The following chapters explore the resolution of conductive heat transfer problems using the finite element method; thermal behavior of composite walls under transient conditions; thermal and electrical models for solving problems of non-stationary heat transfer through walls; and use of a radiometer to measure the average temperature of a wall. Experimental results for mixed air convection along a vertical surface are also presented. This monograph will be a valuable resource for electronics engineers.

Bibliographic Guide to Refrigeration 1965-1968 is a bibliographic guide to all the documents abstracted in the International Institute of Refrigeration Bulletin during the period 1965-1968. The references include nearly 7,000 reports, articles, and communications, classified according to subjects, and followed by a listing of books. This book is divided into 10 parts and begins with a listing of references on thermodynamics, heat transfer, and other basic physical phenomena relating to refrigeration, including desiccation and measurements of temperature, humidity, and pressure. The next sections are devoted to the physics of low temperatures and cryogenics; production and distribution of cold; refrigerating plants (mainly in the food domain); and refrigerated transport and packaging. Other references deal with air conditioning and heat pumps; and industrial, biological, medical, and agricultural applications of refrigeration. The final section focuses on standards and regulations, economics and statistics, and education and trade activities in the refrigeration industry. This guide is intended to assist researchers, engineers, manufacturers, and operators who are in either constant or occasional contact with the refrigeration domain.

The 1965 Cryogenic Engineering Conference, in presenting the papers of its eleventh annual meeting takes this opportunity to gratefuIly acknowledge the assistance of Rice University and, in particular, R. Kobayashi and his staff for serving as hosts for this conference. This meeting, because of its proximity to the NASA Manned Spacecraft Center, has recognized the impact of the space age on the cryogenic field and has, there fore, attempted to emphasize this aspect of cryogenics to a greater degree than in past conferences. The highlight of this conference has been the presentation of the highest Cryogenic Engineering Conference award-The Samuel C. CoIlins Award-to its first recipient, Dr. Samuel C. Collins. This award, set up in his name, has recognized the outstanding contributions that Dr. S. C. CoIlins, retired Professor of Mechanical Engineering at the Massachusetts Institute of Technology, has made in the field of helium liquefaction. His significant advances in various phases of cryogenics have been recognized inter nationaIly by numerous organizations. High on this list has been the tribute which was bestowed on hirn by the Kamerlingh-Onnes Laboratory in Leiden in awarding hirn the first Kamerlingh-Onnes gold medal to an American in 1958. The Cryogenic Engineering Conference, in addition to recognizing his pioneering work in helium liquefaction by the presentation of the Samuel C. Collins Award, also dedicates this volume of the Advances in Cryogenic Engineering to hirn.