safe, there has been no way to tell whether some small part of the beam focused on a limited area of the body might be harmful. The NBS transducer can measure the smaller segments of the beam and provide the needed information. Because of this special capability, FDA has been using the Bureau's innovation to better characterize ultrasonic doses.

NBS uses its nuclear research reactor for a variety of experimental work, including the analysis of environmental and biological materials. Radiochemist Tom Gills inserts a sample into the reactor.

Meanwhile, the Center for Mechanical Engineering and Process Technology initiated an international comparison of measurement methods used to determine the power output of conventional ultrasonic transducers. These powerful measurement methods are used to help establish safe, effective levels of ultrasound for medical applications and for establishing performance characteristics for transducers used in ultrasonic nondestructive evaluation of materials. Four specially designed NBS devices have served as the basis for the comparison.

Using the NBS nuclear research reactor, scientists from NBS and a number of other Federal agencies have helped solve some of today's most urgent problems, including public health protection. The reactor has recently been put to work in analyzing more than 120 foods for toxic and harmful contaminants. This continuing project for FDA-which has several of its staffers stationed at the NBS reactor-uses a very sensitive neutron activation analysis method. The project has established baseline levels of contaminants in foods so that over a period of years it will be possible to monitor whether our food is becoming more contaminated.

The reactor was also used by NBS scientists in a collaborative effort with the NIH Laboratory of Molecular Biology in a study of enzyme structures. These researchers developed a method to determine the structure of very large, complex macromolecules, such as those in body enzymes and proteins. They then used this method and a high intensity neutron beam to study ribonuclease, a digestive enzyme. Scientists conducting this research were particularly interested in structural details related to hydrogen bonds in the protein chains-information which is critical to an understanding of all enzymes but very difficult to obtain with conventional techniques. This NBS effort is the only one of its kind in this country and is one of just three such studies being carried out in the world. It is a prime example of how unique NBS experimental facilities and technical talents are put to work in advancing medical research and contributing to the improvement of public health.

Over the past several years, the Department of Energy (DOE), other government agencies, Congress, and private industry have been looking to NBS more frequently for the Bureau's energy-related measurement expertise. NBS has taken advantage of its broad, multidisciplinary capabilities in responding to the dual energy technology challenges of increased conversion efficiency and greater end-use conservation. Guided by the Bureau's Office of Energy Programs, important energyrelated tasks are being carried out in every major unit of the National Engineering Laboratory. Several units of the National Measurement Laboratory also have energy-related activities underway.

Conserving Energy in Buildings and
Consumer Products

When the National Energy Conservation Policy Act (NEA) was signed into law in November 1978, it authorized a full slate of programs for energy conservation in buildings, including tax credits for homeowners who install energy conserving devices in their homes, requirements that utilities offer to inspect and analyze the energy efficiency of customers' dwellings, and minimum efficiency standards for appliances.

The law also calls for a series of guidelines and standards to be adopted by the Federal government in carrying out the conservation provisions. Even before the statute was passed, NBS had been working with DOE on related research programs. The Bureau is formally mentioned in the energy law a The performance of an evacuated tube solar collector is monitored by NBS engineer John Jenkins. Solar energy research at NBS has led to some of the first voluntary standards for solar collectors and storage tanks. Standards are a first step in boosting confidence in this maturing industry.

number of times and also has been selected by DOE to provide needed performance criteria and measurement technology where there is no specific technology where there is no specific Congressional assignment made to NBS or to the Department of ComNBS or to the Department of Commerce. With its historic role as a focal point for building research within the Federal government and its particular expertise in buildings and energy conservation, the NBS Center for Building Technology has contributed to many of the NEA tasks related specifically to energy conservation in buildings. The Center for Fire Research and the Center for Consumer Product Technology also have been involved. The Bureau does not actually set any of the standards called for in the statute, because NBS is not a regulatory agency. Rather, NBS performs the technical energy conservation research needed to help voluntary standards-setting groups or government agencies make their decisions about standards.

One major portion of the NEA requires utilities to inform their residential customers about energy conservation measures they should consider and to offer to inspect dwellings and analyze their energy efficiency. As part of this NEA utility program, DOE is authorized to develop standards necessary for the general safety and effectiveness of any residential energy conservation measure, with installation standards receiving special mention. Bureau engineers played a significant part in providing DOE with a technically-sound basis for deciding on those standards for energy conserving retrofit measures, including insulation,

replacement oil burners, and storm windows. These standards may well be applied to other conservation programs included in the law. Also at the request of DOE, the Center for Building Technology developed a computer program that could be used to determine the most appropriate measures for various classes of buildings in different climates.

The NEA also directs the establishment of energy conservation targets for Federal buildings and authorizes a massive energy analysis and retrofit program. NBS has been involved in developing those targets. The law further mandates the use of "life-cycle cost analysis" on all Federally-owned buildings, covering both existing and proposed new structures. Life-cycle cost analysis is a method for evaluating the economic feasibility of building design and construction alternatives, taking into consideration all relevant lifetime costs and benefits. In terms of energy conservation projects in buildings, this technique offers a way to evaluate the net effect over time of reducing fuel costs by purchasing, installing, maintaining, operating, repairing, and replacing energy-conserving features. Although the technique is becoming more commonplace, there has been a lack of uniformity and consistency in its

use.

Working to implement a Presidential Executive Order regarding Federal energy conservation programs and lifecycle cost analysis, economists in the Center for Building Technology devised and published an approach that could be used widely, not only by Federal building managers, but by other

building owners, designers, and operators as well. This NBS analytical technique is being used to meet similar life-cycle cost requirements included in the NEA.

An extension and expansion of a grant program to assist low-income families in making their homes more energy efficient is among the many NEA conservation provisions which do not single out NBS to perform a special task. However, this program will be drawing upon the technical information generated by the Bureau from its previous and current technical research or programs established by other legislation. NBS has helped DOE select the criteria for materials and products used in that grant program. Also, at the request of the Community Services Administration, Bureau engineers last year assisted that agency in training personnel for a similar program in lowincome housing energy conservation.

Minimum energy efficiency standards for major household appliances to be set by DOE under the energy law will be based upon research and testing procedures undertaken by the Center for Consumer Product Technology and the Center for Building Technology. Evolving from an earlier Department of Commerce program, and as part of its assignment under 1975 and 1976 Federal energy conservation laws establishing voluntary and mandatory appliance labeling and efficiency programs, these centers have now developed methods for testing more than a dozen categories of appliances for energy efficiency. The appliances range from room air conditioners and water heaters to kitchen ovens and dishwashers. Particularly significant has been the development of testing procedures for certain appliances based

on seasonal or "part-load" performance. This method permits a more realistic estimate of the annual cost of using the appliance by taking into account the energy performance effects of constant on-off cycling.

NBS studies involving energy conservation in buildings are also designed servation in buildings are also designed to meet the goals of other legislation or to satisfy special needs of government agencies or the private sector.

The testing of insulation flammability carried out in the Center for Fire Research illustrates this work. Using the Bureau's extensive fire test facilities and constructing special test apparatus, engineers in the center were able to gather information about the flammability of a variety of thermal insulation products and develop two new flammability tests.

For one of the recommended test methods, the attic floor radiant panel test, researchers used a modification of a laboratory device which had been utilized to judge the flammability of carpeting in prior Bureau research. Soon after the NBS methods were recommended, the General Services Administration adopted them in specifications applying to Federal

insulation purchases. They were also published by the Consumer Product Safety Commission for public comment and possible inclusion in the agency's mandatory cellulosic insulation standard ordered by Congress in 1978.

In this same safety area, researchers in the Center for Building Technology tested the effect of sandwiching electrical wiring between thick layers of insulation. Preliminary results indicated that the wires could reach temperatures higher than currently accepted code levels. Follow-up research sponsored by DOE is being conducted to learn more about this possible hazard.

In addition to this work, listed below are several significant energy conservation achievements from the Bureau's Center for Building Technology.

• Working with DOE through the NBS Office of Energy Programs, a 5year national program plan for research on insulation and the building envelope was drafted. The plan will help direct and coordinate Federal and private sector efforts to answer the most important research questions in this area. Special emphasis has been placed on

current and future NBS and DOE research to assess how entire building sections-like walls, floors, and roofsperform as a system to retard the flow of heat into and out of buildings. The plan also addresses problems of insulation performance and safety.

Having extensively instrumented three test homes in Houston, Texas,

Bureau engineers concluded that powered attic ventilators may not be as effective in cutting air-conditioning costs as has sometimes been suggested. At the same time, the research provided data to quantify the obvious energy savings that can be achieved by ventilating a residence with a wholehouse fan instead of cooling it with an air conditioner.

resistance of thicker layers of insulation.

The 11-story administration building at NBS headquarters was instrumented as part of a DOE-sponsored project to determine how much the flow of outside air in a normally functioning office building may be reduced without affecting the comfort of occupants. The data that are gathered will be useful in several projects concerned with the relationship between ventilation and energy conservation.

Boosting Solar Energy Use

The many NEA incentive and demonstration programs for solar energy applications in home heating, hot water, and cooling will rely heavily on earlier Bureau research and standards work conducted under the Solar Heating and Cooling Demonstration Act of 1974 and other programs. For example, researchers in the Center for Building Technology's Solar Technology Program recently revised the interim performance criteria for residential solar heating and cooling systems. These guidelines are used in the multi-year Federal demonstration program which has led to assistance for several thousand dwelling units incorporating solar systems.

Bureau engineers also verified a standard for judging the performance of devices which store up a solar energy system's heat. This standard had been drafted originally by NBS and later was adopted by the American Society of Heating, Refrigerating, and AirConditioning Engineers (ASHRAE). Following a Bureau tradition of developing draft documents that can be used by voluntary standards organizations and subjected to public review through established consensus procedures, NBS engineers last year