designing cryogenic systems. If the necessary data to complete a table are not available from the literature, values are computed from correlations based on theory and the properties of related materials.

Extensive tables of the thermodynamic data for carbon monoxide were completed together with a temperature-entropy diagram and a compressibility factor diagram. A compilation of the dielectric constants of cryogenic fluids and an extensive bibliography of the thermophysical properties of argon were also completed.

Temperature-entropy diagrams for helium and neon, and an enthalpyentropy diagram for helium were constructed and are now available. Also available are interim reports with preliminary thermodynamic data tables for oxygen and argon. Further evaluation of these materials is in progress. In other work, a bibliography on the saturation properties (vapor pressure, saturation densities, latent heat, and specific heats at constant saturation) of cryogenic fluids was compiled and is in the process of publication. In addition, a collection of thermodynamic data for hydrogen in its various phases and ortho-para modifications is being developed.

Cryogenic Literature Service. The Cryogenic Data Center's documentation unit searches the world literature for technical information per

Fermi surfaces of copper viewed along the (100) direction. The lines depict various electron orbits of importance in theoretical calculations.

tinent to the cryogenic engineering field and promotes an awareness of such literature to the Bureau staff and the cryogenic industry. Over 6,000 references were noted and coded for entering into the Center's storage and retrieval system. Additional mechanization (digital computer programming) to reduce the number of manual operations was accomplished, thus reducing unit costs and providing more capacity with existing facilities.

More than 3,300 documents, of which about 1,300 are in microfilm, were procured from world sources for the Bureau staff. The staff distributed an estimated 18,000 items of NBS literature in response to some 1,900 requests. Periodic announcements of available material and services were sent to approximately 4,000 persons and institutions on the Center's mailing list.

A weekly current awareness service was started in March in which about 100 new articles of interest to the Cryogenic field noted during the week were listed and distributed to the Bureau staff. An expansion and improvement in the service is planned with the intent to make it more available to the public.

The documentation unit works closely with the Center's evaluation unit in providing both literature-procurement services and bibliography retrieval. The evaluation unit is not only a primary user of these services, but is also a major contributor of information on cryogenic literature from their compilation programs and the associated literature searching on selected topics.

Measurement Methodology. Typical projects include investigating new thermometric materials; devising simpler calibration-correlation methods; and the modeling of transducer characteristics on analog and digital computers. Research is performed upon those properties of materials, matter-matter and matter-energy interaction, which may lead to new or improved measurement coefficients. Current examples include the study of nuclear magnetic resonance techniques which may be applied to measure the density or velocity of cryogenic fluids; pyroelectric phenomena for measuring small temperature differences; and the piezoresistivity of commercial carbon composition resistors which may be used to measure pressure.

An especially challenging task during the past year was the investigation of transducers for use in the extreme synergistic environment of combined nuclear radiation and low temperatures. In this case, transducers must operate from 20 to several thousand degrees Kelvin in a radiation field unmatched by any existing test reactor.

Continuing programs include investigating means of measuring the density of flowing cryogens, studying the properties of semiconductors at low temperatures, analyzing the temperature dependence of pressure sensors, and determining the fraction solids in a mixture of liquid and solid hydrogen.

Fluid Flow and Heat Transfer. A study was completed on the pool boiling of cryogenic fluids. This study compiled the experimental data available and compared these data with correlations derived for fluids at higher temperatures. The more promising correlations were indicated and graphical solutions using these correlations were presented. This will pro

vide designers of a wide range of cryogenic systems with much-needed boiling heat transfer data.

An analytical method was developed which will predict peak surge pressures which are experienced when a cryogenic fluid is introduced into an ambient-temperature transfer line. It was determined experimentally that these pressures may be several times the initial driving pressure for the fluid. Therefore, this information is very necessary to ensure safe design for cryogenic systems.

In many cryogenic systems, a conduit (tube, pipe) containing a cryogenic fluid is exposed to a gas mixture (usually air) containing water vapor. In order to properly design such a system, one needs predictive expressions to determine data such as the heat transfer rates to the gas mixture and the rates of the frost formation on the conduit. An extensive experimental program was carried out to determine these data and an analysis was completed using a modification of rather conventional heat and mass transfer analogies which shows reasonably good agreement with the experimental data.

2.3. INSTITUTE FOR APPLIED

TECHNOLOGY

The nation is currently faced with new demands to put technology to economic use to create new markets, to compete with foreign industry, to apply technology to our public problems, create jobs, and put our technical resources to maximum use as well as to cope effectively with the social consequences of technical change.

Attention is also being called to certain gnawing social problems which exceed in scope any one industry, company, or region of the country. These include:

-the control of air, land, and water pollution.

-the inadequacy of our systems of land transportation (particularly in urban areas) and the unsolved problems of our nationwide transportation system.

-the inadequacy of our low- and middle-income housing.

-the well-advertised pockets of poverty in the midst of plenty.

-the problem, for much of the population, of adjusting to the constructive use of large quantities of leisure time.

The National Bureau of Standards' concern with these problem areas, in ways appropriate to its resources and its traditions, is reflected in the programs of the Institute for Applied Technology. This consists of four principal activities:

-the dissemination of technical information.

-the development of performance criteria.

-the development of tools for the analysis of large-scale problems that cut across Government-industry lines.

---analysis of problems associated with the introduction of new technology.

The Dissemination of Technical Information

The Federal Council for Science and Technology has established within the Department of Commerce, building on the Office of Technical Services, in the Institute for Applied Technology, a Clearinghouse for Federal Scientific and Technical Information. Its scope includes the physical sciences, engineering, and related technology and it is meant to serve as a central point of contact in Government for industry and the technical community (paralleling the Library of Agriculture and the Library of Medicine, in their fields). Its specific responsibilities are listed on page 167.