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NIST

PUBLICATIONS

NIST

Research Reports

.U57

#770

1990

C.2

U.S. Department of Commerce

National institute of S^Ktards and Technology

NIST Sp^ial PiAlication 770
NATIONAL INSTITUTE OF STANDARDS

TECHNOLOGY

Research Informatkm Center

Gaithersburg, MD 20899

&

DATE DUE

On the cover: A computer-generated

view of the protein that "turns on"

genes. All life processes depend on

transferring the coded information In the genetic material, or DNA, into useful proteins. In its active form

this protein binds to DNA and triggers the decoding reactions. The diagram's

cylinders and arrows represent different repeated shapes. David Bacon at the Center for Advanced Research in Biotechnology produced the drawing from sfructural information his colleagues deduced with x-ny

crystallography. See article on page 18.

Demco, Inc. 38-293
National Institute of Standards and Technology

ClUou

RNisr 1 jphBi^

esearcn

U.S. DEPARTMENT OF COMMERCE

Robert A. Mosbacher, Secretary

National Institute of Standards and Technology

Gaithersburg, MD 20899

301/975-2000

Boulder. CO 80303

303/497-3000

January 1990

NIST Special Publication 770

Prepared by the Public Affairs Division A903 Administration Building National Institute of Standards and Technology

Gaithersburg, MD 20899

301/975-2762

Any mention of commercial products

is for information only; it does not imply recommendation or endorsement

by the National Institute of Standards and Technology nor does it imply that the products mentioned are necessanly

the best available for the purpose. Nisr

Research Update

The Long Road to Superconductivity 5

Following the Low Road 10

An Answer to the Challenge: Automation 13

Biotechnology Research Facility Dedicated 16

Switches That Turn On Genes 18

The Shop of the '90's 21

How To Reduce the Risk of 'Virus' Attacks 22

Perfornnance of Steels Exposed to Fire Predicted 24

Model To Fight Fire Deaths, Costs 26

Data, Anyone? 28

New Publications 30

Conference Calendar 32
Research Update

Two U.S. Companies Receive Top

Quality Award

Milliken & Company and Xerox Corp.'s

Business Products and Systems, two

U.S. manufacturing companies,

received the 1989 IVIalcolm Baldrige

National Quality Award on November 2

for superior quality in thieir management

systems. President Bush, who presented

the awards, praised the two companies

for "leading the resurgence in American

business leadership." Improvements in quality and service by American companies are "national priorities as never

before," Bush said. The award, named

after former Commerce Secretary

Malcolm Baldrige, was established by

legislation passed in August 1987. It promotes national awareness about the importance of improving total quality

management and recognizes quality

achievements of U.S. companies. The

award is managed by NIST, with the

active involvement of the private sector. For information on applying for the award, contact the Malcolm Baldrige

National Quality Award Office, NIST,

A1 123 Administration BIdg., Gaithersburg, MD 20899.

Nontoxic Acids Are Basis for New

Class of Cements

A new family of nonaqueous dental cements has been developed based on

nontoxic dimer and trimer acids. They can be used in temporary fillings and lin- ers, and as a foundation for other restorative materials. The new patented formulations use a dimer and/or a trimer acid

derived from the partial polymerization of simple unsaturated fatty acids. These

liquids can be mixed with a variety of basic powders used in restorative materials such as zinc oxide and calcium

hydroxide. When mixed with powders.

the bulky, flexible, hydrophobic nature

of the dimer and trimer acids with their relatively low carboxylic acid content produce cements that are tough, low

shrinking, water resistant, hydrolytically

stable, and nonirritating. These new

materials can be replacements for the eugenol cements that are mechanically

and hydrolytically weak. For information, contact Joseph M. Antonucci, NIST,

A143 Polymers BIdg., Gaithersburg, MD

20899,301/975-6794.

Industry To Study Wear

of Ceramics at NIST

The Carborundum Company, Inc., Niagara Falls, N.Y., is sponsoring a Research Associate Program at NIST to study the tribological characteristics of ceramics and ceramic composites under

various temperatures. Carborundum

researchers will use a NIST hightemperature wear test facility and other

special equipment to conduct studies on the friction, wear, and mechanical

behavior of advanced ceramic materials. NIST currently is conducting a tribology

research program that includes

advanced ceramics, coatings, and

composites as well as the lubrication re- quirements of these materials. For further information, contact Said Jahanmir, NIST,

A215 Metrology BIdg., Gaithersburg, MD

20899, 301/975-3671.

NIST Launches Consortium

To Develop Futuristic Lab

With the goal of pooling the resources of industry, government, and academia to develop a totally automated analytical

chemistry laboratory, NIST has instituted the Consortium on Automated Analytical

Laboratory Systems (CAALS). In the

laboratories of the future, automated

devices—including robots—will perform

the entire analytical procedure under the

control of a sophisticated computer sys- tem. Analytical laboratory work often is labor intensive, performed by high-cost

employees using expensive equipment.

This makes the millions of yearly chemical analyses quite costly to industry and

underscores the potential benefits of an automated laboratory. CAALS will pool the resources of a variety of experts to create a world-class team that will pro- duce a viable robotics system that can

be freely adapted. For information on participating, contact H.M. (Skip) Kingston,

NIST, A353 Chemistry BIdg., Gaithersburg, MD 20899, 301/975-4136.

New Database Will Compile OS!

Test Results

in a move to speed the development and

use of commercial networking products

in industry and government, NIST and

partners from private industry are developing a computerized database of commercial products that have implemented successfully the Open Systems

interconnection (OS!) standards and are

interoperable. The participating vendors

will test their products using OSINET, an

experimental computer network coordi- nated by NIST. When it is established, users will have free, on-line access to the

results. Vendors participating include

Digital Equipment Corp., Hewlett- Packard, IBM, NCR, Retix, Touch Communications, Unisys, The Wollongong

Group, and Xerox. For further information, contact Gerard Mulvenna, NIST,

B21 7 Technology BIdg., Gaithersburg,

MD 20899.

2
Improving Purity of Diode Lasers

Using optical feedback and electronic techniques, NIST scientists have

achieved a 10,000-fold improvement on

the color purity of commercial diode

lasers. Typical diode lasers have spectral linewidths the range of colors emitted

that are tens of megahertz wide; NIST

scientists obtained linewidths of less than

1 kilohertz. The techniques also automatically stabilize the laser's oscillation frequency. The narrow linewidths and

frequency stabilization make the diode

lasers, which have low cost and high effi- ciency, attractive for applications in highresolution spectroscopy and precision

measurements. Narrow laser linewidth

will also be a key feature in the next generation of lightwave communication

technologies. Additional studies involving modification of the diode lasers, such as changes in the antireflective coatings,

will be undertaken. Two papers outlining some of the techniques are available from Jo Emery, NIST, Division 104,

Boulder, CO 80303, 303/497-3237.

Soft-Drink Glass Bottle Standard

Revised

NIST has published a replacement voluntary product standard on glass bottles for carbonated soft drinks. The standard,

which supersedes PS 73-77, is for manufacturing requirements to improve the

safety performance of refillable and nonrefillable glass bottles made from sodalime-silica glass with nominal capacities

up to 36 fluid ounces. It was sponsored

by the Glass Packaging Institute, Inc., and developed by a standing committee

of representatives from soft-drink bottle manufacturers, bottlers, consumers, and

others interested in performance requirements, inspection, and testing proce- dures for soft-drink bottles. NIST, a nonregulatory agency, administers the U.S. Department of Commerce Voluntary Products Standards Program in support of private-sector standards development.

Specific activities are initiated in re- sponse to requests from interested parties and subsequent approval by the Secretary of Commerce. To obtain a copy of Voluntary Product Standard PS

73-89, Glass Bottles for Carbonated Soft

Drinks, send a self-addressed mailing

label to the Office of Standards Management, NIST, A625 Administration BIdg.,

Gaithersburg, MD 20899, 301/975-4023.

New Material Will Help Gauge

Cholesterol in Eggs

A new NIST Standard Reference Material (SRM) can help researchers produce

accurate data on how much cholesterol

is present in egg samples. Laboratories can use the NIST materials to develop

cholesterol-measuring methods or to vali- date existing techniques. The SRM consists of three capped glass bottles, each

containing 8 grams of dried whole egg

powder certified to have a cholesterol concentration of 19.0 milligrams per gram, plus or minus 0.2 mg/g. It is avail- able for $95 from the Office of Standard

Reference Materials, NIST, B31

1

Chemistry BIdg., Gaithersburg, MD

20899, 301/975-6776.

Copper Reduces Toxicity

of Burning Polyurethane

Adding a minute amount of copper to

flexible polyurethane foam, widely used

as padding in upholstered furniture, can

reduce the toxicity of smoke during a fire, say researchers at the NIST Center for Fire Research. Hydrogen cyanide (HCN),

a colorless, highly toxic gas, is among

the toxicants that can be produced when

nitrogen-containing materials such as

polyurethane foam burn. NIST re- searchers found that adding as little as

0.1 percent of copper to the foam signifi- cantly reduced both the atmospheric concentration of hydrogen cyanide and the

toxicity of the smoke. For several years, the project has been sponsored partially

by the International Copper Association

Ltd. In the upcoming year, the Society of the Plastics Industry also will be lending

support. According to the National Fire Protection Association, each year in the United States about 1,600 people die in 70,000 fires that begin with a cigarette

that is dropped onto furniture, the bulk of which contains polyurethane foam. Overall, about 6,000 people die in fires in the United States each year. Most of these

deaths are due to smoke inhalation and

not to burns.

Educational Version of DIPPR

Database Available

A special educational version of DIPPR

(Design Institute for Physical Property

Data) Data Compilation of Pure Compounds, 1989 is available for chemistry

students on diskette or tape. The new

database provides students with quick access to important information on the behavior of substances and their reactions under various pressures and

temperatures. It contains evaluated data on 39 properties for 100 chemical compounds most frequently used in class- room exercises. For the chemicals

selected, data are provided on their thermodynamic, physical, and transport

properties. Designed specifically as a

teaching tool, the database is not for research use because of the limited number of available chemicals. NIST

Standard Reference Database 1 1 A, DIPPR, Student (Educational) Data

3
Compilation of Pure Compound Properties, 1989, is available for $75 from the

Office of Standard Reference Data, NIST,

A323 Physics BIdg., Gaithersburg, MD

20899, 301/975-2208.

Accurate Gauging of Food

Components Is Aim of RIVI's

Scientists are continually striving to make

accurate measurements of nutrients and

contaminants in food samples. But they

need standards to ensure the reliability of instruments and analytical methods

preferably standards containing a variety

of foods representative of an American

diet. A reference material (RM) now avail- able from NIST offers just such a dietary

composite complete with values for a

variety of nutritional and potentially toxic components. The material contains listed concentrations of 17 elements as well as

ash, fat, protein, total sugar, and starch. Food chemists can analyze the RM as

they would any food sample and compare their results with the numbers pro- vided. The material, known as Mixed Diet (RM 8431 A), is available for $1 14 from

the Office of Standard Reference Materials, NIST, B31 1 Chemistry BIdg.,

Gaithersburg, MD 20899, 301/975-6776.

Hearing Announced on Federal

Role in Standards

Whether or not the U.S. standards sys- tems, as they now exist, adequately

serve the nation's trading needs in today's international markets will be

the topic of a special public hearing on

April 3, 1990. Marketing, manufacturing,

engineering, and design professionals are invited to testify at the NIST- sponsored hearing. They will be asked

to comment on what the U.S. role should

be in international standards, describe

any problems associated with the acceptance of U.S. products in foreign

markets, assess the current situation, and provide suggestions for improvement. Information and comments will be

used to make recommendations to the Secretary of Commerce to improve the ef- fectiveness of U.S. participation in inter- national standards-related activities. A

written request to participate in the hearing should be submitted by Mar. 22,

1990, to Stanley I. Warshaw, Office of Standards Services, NIST, A603 Administration BIdg., Gaithersburg, MD 20899,

301/975-4000. The hearing will be held at 9:30 a.m. in the auditorium of the Department of Commerce in Washington, D.C.

Individuals unable to attend may submit

written comments to Warshaw.

Making Sound Business

Decisions on Automation

AutoMan, a microcomputer program

developed at NIST, applies modern mathematical techniques to make factory auto- mation decisions easier. Choosing

whether or not to invest in automated

manufacturing equipment is a complex

problem for shop and factory owners. AutoMan, developed for the U.S. Navy's

Manufacturing Technology Program, al- lows managers to account for important

gains realized by automation, including

engineering performance improvements,

better control over manufacturing, and

improved product quality, as well as

harder-to-handle intangible benefits like technology advancement, plant modernization, flexibility, and competitive position. The program for MS-DOS-based machines is available from the National Technical Information Service, Springfield, VA 22161 for $40 plus $3 for shipping and handling. Orders may be

placed by phone: 703/487-4650. Order

by PB# 89-221741. Please specify dis- kette size 5.25 or 3.5.

New Center for Dental Materials

Research Announced

A new Center of Excellence for Materials Science Research has been established

to expand the internationally recognized

dental and medical materials program at NIST. The center is funded by a 5-year

grant from the National Institute of Dental Research (NIDR). The NIDR grant was made to the American Dental Association Health Foundation (ADAHF), which maintains the Paffenbarger Research Center

at NIST. The first year award is for $307,238, with additional funding to be

appropriated over the 5-year period. Initial research projects will include: developing glass ceramic inserts to strengthen and stabilize composite dental restorations; improving the properties

of resin-based composite dental materials to reduce shrinkage; and developing protective coatings for both enamel

and dentin to prevent caries on exposed

roots and to seal restorations.

NIST Helping To Modernize IRS

Computer System

The NIST National Computer Systems

Laboratory recently signed an agreement

to provide technical support to the Inter- nal Revenue Service (IRS) in its redesign

of the tax administration system. One of the major goals of the project is to ensure

that future technologies can be incor- porated into the system without disruption or redesign. IRS will look to NIST for technical guidance in the final design,

specification, implementation, and test- ing of a system. Also as part of the agreement, NIST will provide technical evaluations regarding various hardware and

software architectures and technology. Plans call for the project to be completed

by October 1991.

4
The Long Road

to Superconductivity

hree years ago, the new "high-temperature" superconductors

burst forth, bringing popular visions of unlimited power storage,

fantastically fast computers, resistance-free power lines, and

trains levitated above their tracks. These new materials, like

precocious children, promised a great future because of their

talent for conducting electricity without losing any energy. Ordinary wires

conducting electric current waste energy by converting it to heat. In the ideal case, superconductors

conduct with no resistance—electricity could circle a loop of super- conducting wire forever. This ability to superconduct is not new. The "low-temperature" super- conductors did this trick for years, but only when cooled with expensive liquid helium to a few

degrees above absolute zero. The new high-temperature materials become superconducting in the relative warmth of cheaper

liquid nitrogen, at 77 kelvins (-321 °F). After several years of re- search, however, the new super- conductors have proved difficult children. Scientists have toiled to

train these materials to do useful

Editor's note: This article describes

only a portion of the high-temperature

superconductivity research under way at NIST. For a connplete listing of papers or a collection of abstracts published by NIST researchers on

this subject, send a self-addressed

mailing label to Edie DeWeese, NIST,

724.00. Boulder. CO 80303.

work. These new superconductors tend to balk at carrying high

levels of power or generating

powerful magnetic fields—refus- ing to function under a substantial current or magnetic field. To

make matters worse, these brittle ceramic materials often shatter when pushed to become a useful shape, such as a wire. Today, scientists and engi- neers still struggle to get their stubborn prodigies to behave. At NIST, in both its Gaithersburg,

Md., and Boulder, Colo., laboratories, experts in physics, chemistry, ceramics, and electronics chip away at the superconductivity problem.

Scientists at NIST were well- prepared for the arrival of the new

superconductors—they had been

studying the low-temperature

variety for some time. "We have

worked with superconductivity

for more than 20 years," says

NIST's Frederick Pickett, who

heads Boulder's superconductor

and magnetic measurements

group. (See article on page 10.)

Low-temperature super- conductors already run many

devices. "Our work with low- temperature superconductors

applies directly to research on the high-temperature ones," says NIST electronics expert

Richard Harris. "We use the low- temperature devices as models

for future high-temperature ones." NIST researchers now contribute to the effort to surmount

the many obstacles in the path to workable high-temperature superconductivity. Some are learning

to measure key properties of the

materials and to tailor these properties, seeking the conditions

under which the superconductors

behave best. Other NIST scientists are trying to unravel the still unsolved mystery of how the hightemperature superconductors

work, using mathematical models, electrons, protons, and

neutrons to probe the materials. Superconductors function

differently from ordinary metal

5
NIST physicist Ronald Goldfarb inserts a hightemperature sample into an ac susceptometer for magnetic measurements.

conductors. In an ordinary conductor, electric cinarges tumble

along their way, bumping into metal atoms as they go. Imperfections and unruly vibrations in the atomic arrangements hinder the

electrons' paths, creating the "re- sistance" that steals energy from

ordinary conducting cables and

wires. In a superconductor, on

the other hand, electrons pair up

and maneuver gracefully through

shifting spaces in the material's

crystal lattice, moving in rhythm

with its atomic vibrations.

In low-temperature super- conductors, theorists believe that atomic vibrations act to pair the electrons, enabling them to flow unimpeded. However, scientists aren't sure the new hightemperature superconductors

work the same way. Some re- searchers suspect some type of

magnetic force may play a role, but the process remains a mystery. NIST scientist David Penn is collaborating with Marvin Cohen,

of the University of California at Berkeley, to develop theories for the process. Meanwhile, NIST physicist

James Rhyne and his colleagues

have uncovered some of the first clues to the mystery by looking

into the superconducting materials with neutrons. Neutrons work

much like x rays to reveal the

inner structure of materials. Probing with neutrons from the NIST research reactor, Rhyne's

group has improved our picture

of the arrangement of individual atoms in crystals of the first known high-temperature super- conductor, yttrium-barium-copper

oxide (YBCO).

Recently, Rhyne replaced

various atoms in the super- conductor to determine which ones contribute to superconductivity. He explains that copper

atoms sit in two kinds of sites

chains and planes. He found that replacing copper in the plane

sites destroys superconductivity, but replacing the chain copper

atoms leaves it unaffected. He

concludes that superconducting

current travels along the planes,

not the chains. Surface scientist Richard

Kurtz and his colleagues also study superconducting materials,

including YBCO, but use light rather than neutrons. They investi- gate the character of electrons in the material to determine which ones stay bound to atoms and

which ones help superconduct.

Many scientists originally believed copper in YBCO gave up

three electrons. The surface

scientists' investigation supported

a different scenario—with these

copper atoms only giving up two

electrons and the superconductivity traveling via a missing electron

or "hole" associated with the oxy- gen atoms. By using light from a

synchrotron radiation source to probe specific atomic sites, NIST

physicist David Ederer and his colleagues provided additional convincing evidence for this view. Resistance-free current flow

tells only half the story about

superconductors' special properties. Magnetism reveals the other

half. Magnetism comes inseparably intertwined with electric

effects. Magnetic, as well as electrical, properties distinguish su- perconductors from ordinary materials. "You need two criteria to confirm superconductivity," says NIST magnetism expert Robert

Shull. "You need to measure zero

electrical resistance and to show

the material expels a magnetic

field." Shull explains that an ordinary

magnet generates a magnetic

field —a force field that loops

around the magnet, penetrating

like a ghost through nearby objects. But a field will avoid the in- side of a superconductor. Place a superconductor near the magnet

and the superconductor will push some or all of the magnet's field out of its interior. The superconductor actually does this by creating its own magnetic field equal

and opposite to the one from the

external magnet. In the ideal

6
case, the total field inside the su- perconductor adds up to zero. By creating such a counteracting field, the superconductor

becomes a temporary magnet

or diamagnet—oriented in the opposite direction to the actual magnet. Because of their opposite

directions, the magnet and super- conductor repel each other. A

small bit of superconducting material will float above the magnet,

suspended in air like the levitated lady in a magic show.

Magnetic measurement

groups in Boulder and Gaithersburg have provided many important measurements detailing the magnetic behavior of super- conductors and have used magnetic behavior to measure the superconducting ability of many

materials.

Shull and his NIST colleagues

identify superconductors by their

ability to expel a magnetic field, or in other words, become dia- magnetic. NIST researchers have

measured magnetism to confirm

superconductivity of an important

bismuth superconductor and

show several claims of roomtemperature superconductors to be invalid. When heated above their criti- cal temperature or fed too much

current, superconductors suddenly lose both their ability to con- duct current without resistance

and their ability to expel a magnetic field. The NIST magnetic

measurement groups use the changes in magnetism to deter- mine the temperature above

which these materials revert from

superconducting to normal

behavior.

Engineers need to know these

current and temperature limits to develop superconductor applications—whether as power storage

devices, magnets, or electronic switches. The engineer must know under what conditions

these finicky materials will or won't work. The researchers note that only certain ideal, "type I" super- conductors can expel magnetic

fields completely. The more useful sort—"type H"—behave in a more complicated way, says

Shull. The type 11 materials let in

little bits of magnetic field while remaining superconductors. In- stead of spreading out through

the material uniformly—the field penetrates in small units called

fluxoids. When the superconductor leaves the magnetic field, some of these penetrating bits of

field get trapped inside.

Rhyne's group has

improved our picture

of tlie arrangement off

individual atoms

in crystals of YBCO.

This trapped magnetic field

led to an effect called attractive

levitation. NIST scientist Lawrence Bennett and his col- leagues offered the first explanation of the phenomenon. He demonstrates the effect with a magnet

and a small piece of hightemperature superconductor

cooled in liquid nitrogen. First, he brings the magnet near the superconductor. The two materials repel each other. As he

brings the magnet closer, the su- perconductor suddenly changes

its mind, becoming attracted to the magnet. As Bennett lifts the magnet into the air, the superconductor follows it upward and then

hangs suspended slightly below

the magnet as if hung by invisible thread. "When I push the magnet

close enough," he explains,

"some of its magnetic field gets

pushed into the superconductor

and sticks there." When that happens, the superconductor be- comes a magnet with its poles

directed so it attracts the external magnet.

Invading magnetic flux can

also destroy superconductivity,

creating one of the most frustrating roadblocks in hightemperature superconductivity

research, in high-temperature materials, relatively small magnetic

fields drastically cut down the

current that a superconductor can carry before losing its super- conducting power. Researchers

find these fiendish fields im- possible to escape. Even with no

external field, simply running an

electric current through a material can generate a magnetic field strong enough to break down its superconductivity.

The higher the external magnetic field, the lower the current a

superconductor can bear before

reverting to normal behavior. NIST physicist John Ekin and his colleagues have measured the

7
amount of current the major types

of superconductors can carry under a range of magnetic field strengtfis spanning five orders of magnitude.

How can a magnetic field hamper superconductivity?

Threading through the material in

thin lines, the strings of magnetic

field create a resistance when

moved. Electric currents drag

these flux lines across the material and dissipate energy in the process: Hence no more superconductivity.

Under the right conditions,

such as low temperatures, a current can race unhindered over

flux lines because the lines stay

"pinned" in place. Physical defects in the crystal lattice actually set up a snare to create what

scientists call flux pinning. This

pinning works best in low- temperature superconductors. In the high-temperature variety, more flux lines can get up

enough energy to break free from

their snares. Researchers are identifying the kinds of defects that pin flux, hoping eventually to encourage

the right defects, controlling flux pinning to make better-behaved

superconductors. In the YBCO

superconductors, scientists had

suspected discontinuities called twinning planes may snag flux

lines. Such a plane occurs when

part of the asymmetrical YBCO

crystal lattice runs into another

part facing in a different direction. This leaves a boundary plane be- tween the two "twin" crystals.

NIST scientists Debra Kaiser

and Frank Gayle devised a way

to squeeze the twin boundaries

out of a YBCO crystal, pressing it so all pieces of the crystal line up

in the same direction. By comparing the "untwinned" crystals with normal ones, they and their col- leagues in magnetic materials found the special untwinned crystals superconducted virtually as

well as the normal ones. Kaiser

and Gayle concluded that the un- twinned crystals must still pin flux: Structures other than twin boundaries must be holding the magnetic flux lines in place.

The magnetic flux problem

hinders superconductivity across

tiny units of the material—indi- vidual grains. Bigger problems

beset superconductivity in the

"bulk" ceramics, where many

grains crowd together. "Individual grains superconduct pretty well," says NIST ceramics expert

Stephen Freiman, "but things get

much worse when you put grains

together." Impurities and nonsu- perconducting mixtures tend to collect in the boundaries between

grains, destroying the superconductivity of the whole material. Misalignments between adjoining

crystal grains can also derail the superconducting current. Sometimes superconducting current can travel via a weak "coupling"

between grains, but Ekin and

Ronald Goldfarb's work showed

that small magnetic fields can

break down the tenuous coupling

between grains in these materials. NIST researchers experiment

with the process of making super- conductors, learning to minimize

these problems. NIST chemists

and ceramics experts study every

phase of the ceramic-making

process, from mixing the ingre- dients in the right proportions,

to "sintering" the powder into a

solid superconducting material,

to shaping the solid material. Companies interested in making

superconductors often use NIST- produced recipes known as phase diagrams that show the proper mix of ingredients and the

conditions, such as temperature

and pressure, needed to make a

superconducting material. Researchers then face the problem of connecting the super- conductors to ordinary wires

without creating a barrier to superconductivity at the boundary be- tween the two materials. A region

with too much or too little oxygen

will cause such a blockage. Ekin,

working with researchers from the Westinghouse Research and

Development Center, Pittsburgh,

Pa., invented a solution to the problem by coating the superconductor area with silver before connecting it to the ordinary wire. Since oxygen can diffuse through

silver, he found he could control the amount of oxygen at the boundary region, achieving the best mix for superconductivity.

Right now, researchers are meeting success coaxing hightemperature superconductors

to carry higher currents by con- densing thin-film coatings of superconducting materials on nonsuperconducting surfaces.

Harris' cryoelectronics group

makes these films from a va- porized material or a mixture of vapors of the material's constituents. The researchers make a

vapor from a solid sample either

8
by heating it or by bombarding it with lasers or energetic ions to knock atoms and molecules off

into the vapor phase.

By choosing the right surface, the researchers can force the material to condense into the pattern

of a single crystal with no superconductivity-killing boundaries. In

this form, the materials conduct

greater currents and avoid the

pitfalls from grain boundaries that besiege thicker "bulk" shapes.

Harris says high-temperature

superconducting films may be

used in electronic devices such

as detectors for magnetism and

radiation. For example, NIST

scientists are developing an in- frared radiation detector called a

bolometer that may use hightemperature superconductor

films. Kept near its critical temperature, the superconductor

registers radiation by changing

from a superconducting to a nor- mal state as the radiation boosts

its temperature.

Harris' group also worked on

a collaborative project with AT&T

in applying semiconductormaking techniques to superconductors. The team investigated

ways to form very small strucNIST physicist Todd Harvey observes sputter deposition of higli- temperature superconducting thin films used by NIST to develop electronic measuring devices.

tures, like those etched onto computer chips, onto a super- conducting material. Lowtemperature superconductors

already make up a variety of useful electronic devices, and the NIST researchers hope to make

similar devices from the new

high-temperature materials. NIST researchers still hold

high expectations for the new

high-temperature superconductors. "The technology is only

3 years old; there's still a lot to

learn," says Fickett. "I'm as enthusiastic as I ever was." Robert Kamper, head of the NIST superconductivity program,

recalls the way low-temperature

superconductivity research fal- tered at its beginning. After a Dutch scientist discovered

superconductivity in a very cold mercury wire in 1911, scientists rushed to make super strong

magnets and energy storage

devices. Before long they ran up

against nearly impossible problems getting these materials to carry high currents or work in high-magnetic fields. Not until the 1960's did researchers finally overcome enough hurdles to sell useful devices using the low- temperature superconductors.

"In the past, nearly insur- mountable problems cropped up

but people solved them," says Kamper. "I'm sure people will be

able to design around the problems we now have with the hightemperature superconductors,

too."

by Faye Flam

NIST Writer-Editor

9
Following the

Low Road

hile researchers lavish attention on the newborn

"high-temperature" superconductors, the older, lowtemperature superconductors have already led to many

applications of superconductivity. "The recent discovery

of new high-temperature materials renewed interest in the

conventional superconductors that have been around since 1911," says

Frederick Fickett, head of the NIST superconductor and magnetic measurements group. Both types conduct an electri- cal "supercurrent" that loses no

energy in its passage. The low- temperature superconductors

generally the metal alloy of nio- bium and titanium or a compound

of niobium and tin—work only

when cooled with liquid helium to near absolute zero. The new hightemperature materials stole the show in 1986 by working with much less cooling. However, the path to useful high-temperature

superconductivity soon twisted

into a maze of obstacles: The

brittle materials proved hard to work with, pervasive magnetic

fields destroyed superconductivity, and boundaries be- tween "grains" of the material blocked the supercurrent. Lowtemperature superconductors, on the other hand, avoid most of these pitfalls.

"In the short run we may find it easier and cheaper to cool the low-temperature superconductors

the extra amount than to over- come the problems with hightemperature superconductivity," says NIST physicist James Rhyne.

As scores of researchers

drive toward the development of superconductivity, NIST provides

road maps. NIST researchers

Scientists and

engineers worl(ing with

superconductors turn

to NIST for data

on their material's

magnetic properties

and current-carrying

capability.

take these materials and describe

them and measure their key properties. Scientists and engineers

working with superconductors

turn to NIST for data on their material's magnetic properties and

current-carrying capability. NIST

scientists also seek a better un- derstanding of how these materials work and experiment with applications.

Superconductors have been

applied in two main ways: as electronic circuit elements and as magnets. Today, low-temperature

superconducting magnets run many devices, including medical

imaging machines, particle colliders for physics experiments, a Navy ship, and a Japanese levi- tated train. Scientists envision

using superconducting magnets

to squeeze atoms together in fu- sion energy plants.

How does a superconductor

become a magnet? Electric current running through a coil of superconducting wire generates a magnetic field running through

the coil. But too much current or too powerful a magnetic field will destroy superconductivity. Therefore, anyone using superconductors for magnets needs to know

the limits of the material. Scientists in the NIST superconductor

and magnetic measurements

group provide the measurement

10
techniques and the data to deter- mine how much current, magnetic field, and mechanical strain

will break down a magnet's

superconductivity. They also study how superconductors be- have under alternating currents.

In addition to providing measurements, NIST scientists have

contributed to the design of magnets for particle accelerators used in experiments probing the fundamental laws of nature. Some

of these magnets will guide parti- cles down the 50-mile path of the proposed superconducting supercollider in Texas, for example.

Superconductors can also do big things in very small amounts. Two bits of superconductor with a slice of poorly conducting, high-resistance material sandwiched between them make

up a tiny electronic component

called a Josephson junction. Like

transistors in the world of semiconductors, Josephson junctions

process electrical current by

switching between two states

"on" and "off."

In the "off" state, the whole

sandwich superconducts. A ten- dency called the "Josephson

effect" allows the supercurrent to ignore the middle layer, losing no energy as it jumps across the high-resistance material. Raising

the current past some critical value switches the junction to the

other state—the "on" state. In this second state the junction con- ducts an ordinary current that loses energy, especially when

squeezing through the highresistance middle piece.

Scientists in NIST's cryoelectronics group experiment with hooking together Josephson

junctions into useful devices. Several years ago they created an instrument that uses thou- sands of Josephson junctions to provide a standard measurement

of voltage. A copy of this instru- ment enabled the Hewlett Packard Company to define the accuracy of a new (conventional

electronic) digital multimeter and

go to market with world-beating

specifications.

Low-temperature superconductors also gave rise to an

analog-to-digital converter. The

device takes a smooth signal,

such as a song on the radio, and

approximates it as a series of discrete digits. The military is developing the device for instru- ments that detect heat. Such

11
detectors could map out climate

patterns over a continent or detect the heat of a missile. Another application of Joseph- son junctions—the SQUID—also detects targets, in this case by

sensing magnetic fields. Though

this SQUID doesn't swim in the

sea, the military is training it to

sniff out submarines and under- water mines. SQUID'S—for super- conducting quantum interference devices—take advantage of the way small magnetic fields can

break down superconductivity.

The SQUID registers a magnetic

field when the field switches its Josephson junctions out of the superconducting state.

NIST researchers also are making SQUID'S to help Stanford

University scientists verify a

prediction that follows from

Einstein's general theory of

relativity—that a gyroscope will wobble when moved through a

gravitational field. The scientists are looking for such a tiny wobble

that they need a special gyro- scope that gains extra sensitivity

from superconductors.

A gyroscope works like a fast spinning top with no friction to drag it down. Its axis of rotation holds the same angle until some

force pushes on the axis, making

it wobble, or precess like the axis

of a top slowing down.

In the superconducting gyro- scope, a spinning quartz ball coated with a superconductor will generate a small magnetic field when its axis wobbles. Scientists plan to detect this field with a

superconducting detector—the SQUID. The Stanford researchers

expect to launch the experimental

apparatus on the next space

shuttle.

Superconductors

have been applied

in two main ways:

as electronic

circuit elements and

as magnets.

Much of the NIST research

focuses attention on combining

superconducting electronic ele- ments into complex arrange- ments—analogous to computer

chips. The researchers create pat- terns of Josephson junctions.

Since resistance in the circuits now limits the speed and power

of electrical devices, resistancefree Josephson junctions may

lead to much faster electronics. NIST researchers say their work with the low-temperature

materials may eventually be applied to the new high-temperature

ones. Both low- and hightemperature superconductors

promise to break past many limits

further down the road. F.F. NIST electronics engineer Claric Hamilton examines the 1-volt Joseptison series array voltage standard. With about 3,000 junctions, these NIST-fabricated

integrated circuits are used in standards laboratories around the world.

I 12
An Answer to the

Challenge: Automation

ithout minimizing tine importance of the service industry to

the country's economic health, I think I can safely assert

that manufacturing is crucial to our economic and military

security and to the viability of our culture. In short,

"manufacturing matters." New advances in automated

manufacturing technology—robots, computerized machine tools, artificial

intelligence, computer-aided

design techniques, and inte- grated flexible automated manufacturing systems, for example

can make dramatic changes in the country's manufacturing

position.

These advances can improve

production operations of U.S. operations from the standpoint of

quality, productivity, product-life

cycle, materials conservation,

human resource utilization, and

cost. Such improvements, in turn, affect the relative strength of our manufacturing enterprise and

have an immediate effect on our defense industrial base.

The Japanese and others are aggressively exploiting the potential of advanced and automated

manufacturing. I find it very worri- some that in Japan approximately

30 percent of all machine tools are computer-controlled compared with the automation of only

This article was excerpted from tine keynote address given by Deputy

Secretary of Commerce Ttiomas J. f^urrin at ttie NiST Automation Open

House on November 14. 1989.

about 1 0 percent of the machine

tools in this country.

Much of the work by

NIST researchers is focused on applying

advanced technology

to manufacturing

more effectively.

What is slowing the adoption

of automated manufacturing? The

cost and availability of capital is a

big factor. So is the lack of technical expertise on the part of man- agement and staff, along with a common failure to appreciate the importance of quality and productivity. There are problems of compatibility and reliability in equipment and software. Perhaps most important is the broader

lack of long-term business strate- gies for managing companies in ways that allow them to take full advantage of automation.

How do we deal with these

problems? What do we need to do to improve our competitive

position in manufacturing? I believe there are five key ingre- dients to improved competitive- ness for this country—and each

has special relevance to auto- mated manufacturing. Each must be understood and addressed now if the United States is going

to take full advantage of auto- mated manufacturing's potential.

First, we must assure that global competitiveness, including world-class manufacturing, is a

top priority objective for U.S. in- dustry. Second, we must do a far better job at educating and moti- vating our employees, including our managers. This also means

getting more of our best-andbrightest college students to pursue studies and then careers

in manufacturing technology.

In addition, we must apply

advanced technology to manufacturing more effectively—including

the use of concurrent engineering

techniques. And, we must seek

lower-cost sources of capital.

13
while aggressively justifying new

investments by anticipating the

benefits that result: greatly im- proved quality; radically reduced

inventory, building and equip- ment; more rapid commercialization of new products; and im- proved response to changing

customer demands.

Finally, we must sustain quality and productivity improvement.

Quality improvement—properly

defined and effectively implemented in a total quality management approach—is one of the most significant secrets to the

future success of our industrial base improvement.

While NIST appropriately

places major emphasis on manufacturing technology, its automation program addresses each one

of these key items. The data-driven manufacturing techniques developed at NIST and employed at its Auto- mated Manufacturing Research

Facility are helping to equip U.S. manufacturers facing a global

marketplace filled with strong

competitors producing world- class products. NIST's heavy

involvement in U.S. standards

efforts, and in the international standards arena, is helping to assure that standards speed,

rather than slow, U.S. automation

efforts. Much of the work by NIST re- searchers—both in the laboratory

and on standards committees—is focused on applying advanced

technology to manufacturing more effectively. This is much

more than just a research and

development program.

The activities at NIST help to

justify new investments in auto- mation equipment and systems

by proving the benefits that can

result—including more rapid commercialization of new products

and improved response to customers' needs.

And the automation research

at NIST aims to help build quality

into the design and manufacturing process so that parts are made right the first time. Measure- ment is a key. NIST's efforts are a model of how government, industry, and

academe can join together to boost our manufacturing capabilities and overall competitiveness.

More than 50 U.S. companies

large and small—have sponsored

NIST'S efforts are a model

of how government,

Industry, and

academe can join

together. . . .

their researchers to work in NIST

labs on automation-related projects. A similar number of firms have loaned or donated about

$12 million worth of equipment to the automation program at NIST. The Department of Defense, especially the Navy, is a major supporter, and more than three dozen universities have connections with the program. The work at NIST is paying

dividends, helping to assure both

our economic and military security. I truly am convinced that this

work is crucial to improved manufacturing competitiveness for the United States. There are dozens of specific

instances in which NIST automation work has been transferred to help U.S. companies or govern- ment agencies take better advantage of automation technologies.

Today, that process continues as NIST is: assisting the shipbuilding

industry with data standards.

developing theoretical results, participating in standards activities, and otherwise helping to solve a DOD-industry measure- ment problem identified with the use of coordinate measuring

machines.

developing a tool-management system for installation in the Army's Rock Island Arsenal.

It should be clear that tech- nology cannot succeed in a vacuum, that we must do a far better job of managing the tech- nology at our disposal. Business

practices, human resource conditions, and the overall business cli- mate will make all the difference

in the world. We need business-technology

strategies that include concurrent engineering principles, that fully integrate R&D, manufacturing,

and marketing functions. We

need business-technology strate- gies that specifically take into account our competitors' ad- vances and our own strengths

and weaknesses.

NIST is addressing these

broader business-technology

issues as part of its traditional

14
laboratory-based activities and as

it carries out new responsibilities

under the Omnibus Trade and

Competitiveness Act of 1988. Under that law, NIST is charged

with providing technical expertise

and assisting small and mediumsized businesses to adopt auto- mation techniques through Regional Manufacturing Technology

Centers. Centers have been es- tablished in Ohio, New York, and

South Carolina. Each of the centers is using

different approaches to survey manufacturers to evaluate client needs. Each center is defining the technologies and services

appropriate for its region and is entering into cooperative agree- ments with vendors and professional organizations.

Satellite centers are being

formed at community colleges

and state-operated manufacturing resources centers. Technology "solution packages" are being developed to minimize "re- inventing the wheel" each time a new manufacturer is assisted. NIST also is involved as part

of a Commerce Department Technology Administration team that has joined with other federal agencies to increase private- sector use of automated manufacturing techniques. These agencies include the Department of Defense, the Office of the U.S. Trade Representative, NASA, and

the Small Business Administration. Among other things, this Interagency Working Group on

Flexible Computer-Integrated

Manufacturing is examining

procurement and regulatory im- pediments to industry automation.

For example, through this group, we are assisting DOD in examining industry accounting proce- dures which discourage invest- ments in flexible automated

manufacturing by using narrow fi- nancial criteria and by failing to take effectively into account factors such as throughput, leadtime, quality, and flexibility. Major representatives of the American accounting industry are participating in an effort to change accounting practices that now act as barriers to automation

investments. With Navy Mantech

program support and in collaboration with a consortium of manufacturers, NIST has addressed the accounting issue by developing a

software package which allows

investors to include nonfinancial

criteria in investment analyses.

This new program is being tested by nearly 50 companies.

Another promising approach

for encouraging greater adoption

of automated manufacturing,

especially by small and mediumsized firms, is shared flexible computer-integrated manufacturing, or FCIM. Promoted by the Technology Administration, which

NIST is part of, a shared FCIM

facility is an automated manufacturing service center that would

lease manufacturing time to small

firms. Such centers are still a new

idea, with the first production

operations now being established, but there is growing interest in the concept.

As we assess the global competitive environment, it is easy to see that U.S. manufacturing faces

Researchers at NIST are applying advanced technology to improve the effectiveness of manufacturing.

rough times ahead. We need to overcome substantial technology,

business, political, and cultural

barriers. Our success ultimately

will depend on how well and how

quickly we address each of these

concerns. We already have

spotted the Japanese a big lead—and other nations are striv- ing to join them at the head of the pack. Now we've got to catch up.

It is through programs like those at NIST, through cooperative efforts that team our re- sources in industry, government,

and academe, that our country can meet the challenges that await us.

15
Biotechnology

Research Facility

Dedicated

niversity and government officials dedicated the new laboratory facilities of the Center for Advanced Research in Biotechnology (CARB) on November 29. One of the first biotechnology research establishments of its kind in the country,

CARB is located at the Shady Grove Life Sciences Center in Montgomery County, Md., and is part of the Maryland Biotechnology

Institute (MBI) of the University of Maryland System.

CARB was established in 1984 as a cooperative venture of the National Institute of Standards

and Technology, the University

of Maryland, and Montgomery

County. It was one of the first bio- technology research efforts involv- ing federal, state, and local

Hie new CARB laboratory facilities are located at the Shady Grove Life Sciences Center in Montgomery

County, Md.

governments in cooperation with a major university.

The new $7.6 million, 40,000-

square-foot facility provides a

world-class research center for multidisciplinary studies in protein

structure, function, and design.

Through close interaction with

industry, CARB researchers are expected to narrow the gap be- tween laboratory discoveries and

industry needs.

In his keynote address,

James Wyngaarden, Associate

Director for Life Sciences, Office

of Science and Technology

Policy, said, "CARB is an important development, and a national resource for accelerating the rate

of transfer of discoveries in bio- technology into practical uses of benefit to mankind. It is an out- standing example of governmentuniversity-industry collaboration, one that can make a difference in keeping this country at the forefront of competitiveness in biotechnology."

NIST Acting Director Raymond Kammer extended an

invitation to the biotechnology in- dustry to become involved in re- search at the center, saying,

"Through its work on protein struc- ture and molecular biology,

CARB will provide information and tools essential to the bio- technology industry. Cooperative

research agreements with private

industry will speed the transfer of

this knowledge and know-how.

These industrial ties are of particu

lar interest to NIST, with our long

history of successful cooperative

research ventures, so let me reit- erate the standing invitation to the biotechnology community to learn how they can make use of this world-class facility." The state-of-the-art laboratories at CARB are designed for

critical areas of research in macromolecular structures and model

ing. The highly instrumented

16
Researchers in the CARB protein crystallization laboratory prepare and ex- amine protein crystals, a first step in determining the atomic structure of proteins.

laboratories include a computer

and graphics laboratory with a

state-of-the-art mini-supercomputer and several high-resoiution

interactive workstations, an x-ray crystallography laboratory, and

laboratories for molecular biology

and biophysical chemistry. A nuclear magnetic resonance (NMR)

spectroscopy laboratory will be

added this spring.

Currently the CARB staff totals 40—including 10 principal scientists (five from MB! and five from

NIST) who are building research

groups in crystallography,

molecular biology, NMR spectros- copy, physical biochemistry, and

computational chemistry and

modeling. In addition, there are 12 staff scientists and technicians, four postdoctoral fellows,

five graduate students, three visit- ing scientists, and six administrative support staff. The total CARB

staff is expected to grow to approximately 70 over the next 2 to 3 years. The CARB researchers are working to understand the struc- ture and function of several important proteins and enzymes including: cytochrome P-450, an enzyme involved in cellular detoxification; beta-lactamase, an enzyme that bacteria use to resist

penicillin-like drugs; and inter- leukin-1-beta, an important protein in the human immune system.

Research programs at CARB

are managed jointly by the Maryland Biotechnology Institute and

NIST. CARB is advised by a board of overseers chaired by

Donald Johnson, acting director

of NIST Technology Services.

The CARB opening also included the dedication of the Isadore M. Gudelsky Memorial.

Through the generosity of the Isadore and Bertha Gudelsky

Family Foundation, 50 acres of land were donated to Montgomery County. This site at Shady

Grove will be developed by the

University of Maryland Foundation. Montgomery County fi- nanced the construction of the CARB facility on the site and is leasing it to the University of Maryland foundation. For information on research at CARB contact Director Thomas

Poulos or Associate Director Walter Stevens, 9600 Gudelsky

Drive, Rockville, MD 20850,

301/251-2272.

by Roger Rensberger

NIST Public Affairs Specialist

The CARB graphics laboratory is used for data analysis, simulations, and theoretical modeling of protein

structures.

17
Switches That Turn

On Genes

f you looked closely, you would see squads of proteins of assorted

shapes doing all the work in your body. Some turn food into energy,

some transport nutrients or waste products, others contract your

arms and legs when you want to move. Nearly every cell in your body

contains a complete set of genetic instructions for making all of the

100,000 or so human proteins—yet each individual cell knows to make just

the right amount of the right

proteins at the right times. A

bone marrow cell makes oxygencarrying hemoglobin, while an intestinal cell makes an enzyme to digest food, and an immune cell makes an antibody to fight for- eign bacteria and viruses. Each

plays its part like a musician

adding to the complex symphony

that brings creatures like us to life. Who conducts the orchestra?

What tells a cell to turn on the protein machinery to decode some

gene? What turns it off when it has made enough? And how do

the genes know to copy themselves before the cell divides?

We know that long, doublestranded DNA molecules hold the chemical code for constructing

each protein. A series of reactions opens a DNA molecule, separates the two DNA strands, and

translates the information coded

in a segment, or gene, into a protein. But we have much to learn about how it ail works.

Scientists at the Center for Advanced Research in Bio- technology (CARB) explore

"With the tools and

techniques of modern

molecular biology we

can begin to see in

atomic detail how

basic reactions work."

some of the unmapped territory. (See related article on page 16.) The experiments of NIST scientists Keith McKenney and Prasad

Reddy and their colleagues in the molecular biology group give a

close-up view of how different molecules signal each other to

act. "We strive to understand

these mechanisms in chemical

terms," says McKenney. "With the

tools and techniques of modern

molecular biology we can begin

to see in atomic detail how basic

reactions work." These tools include gene

splicing (using enzymes to join

DNA at precise points), gene re- combination (linking genes from

different DNA molecules), DNA

synthesis (making DNA in a test tube), and molecular cloning

(using a cell to copy added

genes). These techniques enable

the researchers to alter genes,

reorganizing their code or sequences. By manipulating the genes, scientists can modify or "engineer" the proteins encoded

in these genes. McKenney and

Reddy learn how genes work by

studying the action of their protein product.

Through their experiments,

the researchers learn how fun- damental processes work. McKenney notes that such re- search in molecular biology often leads to unforeseen practical uses within the world of bio- technology, for example, im- proved medical tools for making

vaccines or diagnostic kits or better crops that resist disease and

pests without pesticides.

McKenney and Reddy focus on two questions. First, what

prompts genes to transcribe and

translate their genetic code into a

protein? Second, what triggers

18
DNA molecules to make copies of themselves to pass on to new

cells? To explore the first question—on transcribing and translat- ing genetic code into proteins

the researchers study molecular

signals that trigger the different steps in the process. Scientists

refer to such signals as molecular

"switches" that turn a gene "on"

or "off." The CARB researchers experiment with the molecular switches

of one of the Earth's simplest

creatures, a single-celled bacterium called E. coli. McKenney

and Reddy investigate the molecules that turn on genes that encode a group of proteins called

enzymes. These particular

enzymes break down sugars to extract energy from them.

Just digesting a sugar re- quires a complex set of steps for

this simple bacterium. "When the

cell senses a complex sugar like lactose, it turns on a cascade of reactions that leads to activation

of a protein by a small molecule

called cyclic AMP," McKenney

says.He explains that scientists have developed a clear picture of

the last step, when an "activator" protein actually turns on the gene. This protein can read the chemical code written along the gene. Scientists use the four characters, A,G,C,T, to stand for the

four chemical components of the

gene, known as bases—adenine,

guanine, cytosine, and thymine.

The activator protein binds only to specific sequences of this code.

The long, double strands of DNA containing the genes twist

into a double helix with two differ- ent-sized grooves, like the grooves running around a screw. The activator protein has two "fin- gers" that fit into these grooves. One of these fingers locks into and "feels" a series of bases. In a

string of some 5 million bases,

this protein recognizes and locks

into 50 different short sequences

where it turns on production of 50 different enzymes, all useful in metabolizing sugars. But before the activator protein can turn on these 50 genes,

cyclic AMP must turn on the protein. The cyclic AMP grabs onto

the protein and transforms its shape. It is this step that most

interests McKenney and his colleagues.

It is the protein's three- dimensional structure that gives

it its function. Only 20 different building blocks called amino

acids link up to form all proteins, but each combination folds up

into a unique, complicated configuration of bends and twists. The structure enables the protein

to do its job, whether breaking

down sugars, transporting oxy- gen, or activating genes. Though

the little cyclic AMP is only one

four-hundredth the size of the acti- vator protein, it rearranges the three-dimensional structure enough to convert it from its inactive to its active form.

Left to right, University of IVIaryland DNA ctiemist Joel Hoskins, graduate stu- dent Kalidip Clioudliury, NIST molecular biologist Keith McKenney, and

graduate student Marc Kantorow examine the results of a DNA sequencing

experiment at CARB.

19
McKenney and his colleagues

want to know how this small molecule binds to the activator protein and how it changes the

structure. They are experimenting

with altering this protein through

protein engineering and determining how different changes alter the way the cyclic AMP activates the protein and the way the protein, in turn, activates the gene. McKenney explains that by

protein engineering they don't

actually rearrange or remodel

already-made proteins, but in- stead engineer the genes that code for the protein. "We add the

altered gene to a cell and let it make the new activator protein,"

he says, "Then we see how the al- tered protein works. How well does it work? Does it respond to the cyclic AMP? Does it respond

to any other small molecule? Can

it still fold into its natural three- dimensional structure?" The scientists have made

hundreds of alterations in the acti- vator protein by changing just one or two amino acid building blocks. Researchers then test these modified proteins to see if they can still do their job—in this case turning on genes that pro- duce enzymes that break down a

sugar.

In 80 percent of the alterations, the modified activator failed

to turn on its target gene. Consequently, the cells failed to digest the sugar. In about 20 per- cent of the cases, though, the re- searchers changed the function

of the activator protein without destroying its activity. McKenney

considers those the interesting ones, worth further investigation.

"Once you go through the zoo

of modified proteins and pull out

the interesting ones, how do you

characterize them?" he asks. He

explains that scientists have

developed a structural model describing how individual atoms

and atomic groups interact when

the cyclic AMP binds to the acti- vator protein. The altered proteins

help them to construct and verify

this model. By changing different parts of the protein and noting

subsequent changes in its function, the researchers can

decipher which parts play a key

role in recognizing the cyclic

AMP molecule.

The researchers discovered

that different small molecules

chemical cousins of cyclic AMP

activate some of the modified proteins. Comparing different small molecules provides insight into the way other molecular switches

work as well.

"Once you go

through the zoo of

modified proteins

and pull out the

interesting ones,

how do you

characterize them?"

This particular case provides

just one example of a molecular

switch. It works as a "positive acti- vator" because its presence turns the gene on. All sorts of other molecules activate other genes. Some switches keep genes

turned off. These "repressor"

proteins must release a gene

before it can turn on.

Still other switches tell DNA

molecules to reproduce, copying

their information into new DNA

that goes into new cells. Scientists have even more to learn about this second process.

In exploring this problem, the researchers study a virus-like particle called a phage that invades

bacteria. The phage lives in the

E. coli cell and takes over the

cell's DNA duplicating machinery

for its own use, churning out copies of its own DNA.

The phage needs several proteins from the host cell and one of

its own to start reproducing its DNA. These proteins lock into specific sites on this DNA. The re- searchers know that one phage

protein binds to five sites on its DNA and another protein from the

bacterial host binds to two other

sites. By altering both the sites on

the phage DNA and the proteins

that fit into them, the researchers

are learning how these proteins

trigger the DNA to copy itself. So

far they have found the phage

needs some of the binding sites

to reproduce itself and can do

without others. In some cases

changing the position of binding

sites stops replication, while changing others doesn't. The CARB group expects this work to lead to important applications. Discovering the keys to genetic switches will enable

people to control a cell's proteinmaking machinery, harnessing it

to make large quantities of proteins useful in industry and

medicine. F.F.

20
The Shop of the '90's

he shop of the '90's is not the "factory of the future," it's the

factory of the here-and-now. The National Institute of Standards

and Technology, well-known for its research at the forefront of

automation technology, is solving the autonnation questions

that exist today. Small job shops—operations with fewer

than 50 employees—make up about 85 percent of U.S. metal fabrication

facilities and account for about

75 percent of all U.S. metal

fabrication. They are running

substantially behind their over- seas competitors in the use of modern technology. In Japan, for example, approximately 30 per- cent of all machine tools are computer-controlled as compared to fewer than 1 1 percent in the United States. Sweden and West

Germany also have more computer-controlled equipment than

the United States. What modern technologies

are commercially available, afford- able, and useful to the small job

shop? How are they best intro- duced? What return on invest- ment might be expected? To help answer these questions, NIST is using its own job shop to conduct

an experiment in the practical

implementation of computerintegrated manufacturing.

The NIST Fabrication Technology Division (FTD) designs

and manufactures specialized

instruments and other equipment

for the NIST laboratories. The

workload is comparable to that

of many small job shops in hightechnology industries. FTD

employs just over 50 people in

its main shop and several on-site

contact shops, using a wide

variety of numerical-control (NC)

and manual machine tools of varying vintages. Other duties include

tool and material inventory and

management, cost estimating,

and billing.

In July 1988, FTD began a

project to modernize and improve

its own operations, creating the "Shop of the '90's." To make the

project relevant to small, private- sector job shops, only affordable,

commercially available "off-theshelf" systems and software are being used. Purchases and

changes are justified by a rea- sonable return on investment.

The project involves three stages:

Conducting a thorough review

and evaluation of existing

machine tools and resources to provide a basis for decisions to repair or replace existing tools.

Installing a personal computer

network to support computeraided cost estimation, computeraided process planning, computerized tool room management,

and computerized job and job cost tracking. In addition, design

and manufacturing (CAD and

CAM) systems based on personal

computers were added to speed

design and programming of parts. Training shop personnel in the use of the new systems and

equipment.

The project has already demonstrated a three-fold reduction

in NC programming time and,

because of improved productivity, a 6-month payback time for new equipment.

NIST does not recommend

particular products or suggest

that the products used in the "Shop of the '90's" are the best

for any other machine shop, but

the principles and procedures

developed in the program can be

useful to many small shops.

FTD has established a "Shop

of the '90's" seminar center, which replicates the FTD equipment and software on a small

scale. The center is available to private industry for use in cooperative research programs, to test the compatibility of different soft- ware packages and similar tasks. For information, contact Adrian

Moll, NIST, 136 Shops BIdg.,

Gaithersburg, MD 20899,

301/975-6504.

by Michael Baum

NIST Public Affairs Specialist

21
How To Reduce

the Risk of

'Virus' Attacks

o reduce the risk of damage from potentially serious computer

viruses, experts at the National Institute of Standards and Technology, the National Computer Security Center (NCSC), and the

Software Engineering Institute (SEI) are recommending several

measures plus common-sense computing practices. "This

advice is being offered to encourage effective yet calm response to

recent reports of a new variety of connputer virus," says Dennis

Steinauer, manager of the computer security management and

evaluation group at NIST. "Computer virus" is a term

often used to indicate any self- replicating software that, under

certain conditions, can destroy

information in computers or dis- rupt networks. Other examples of malicious software are "Trojan

horses" and "network worms."

Viruses can spread quickly and

can cause extensive damage.

They pose a larger risk to per- sonal computers, which tend to have fewer protection features and are often used by people

who are not versed in the technical details of the machine.

They frequently are written to masquerade as useful programs

so that users are duped into copying them and sharing them with friends and work colleagues.

While incidents of malicious software attacks are relatively

few, they have been increasing.

Routine use of good computing

practices can reduce the like- lihood of contracting and spreading any virus and can minimize its effects if one does strike. Advice

from the experts includes: Make frequent backups

of your data and keep several

versions.

Routine use of good

computing practices

can reduce the

lil(elitiood of

contracting

and spreading any

virus. . . .

Use only software obtained

from reputable and reliable sources. Be very cautious of soft- ware from public sources, such

as software bulletin boards, or sent across personal computer

networks.

Don't let others use your computer without your consent. Use care when exchanging

software between computers at work or between your home computer and your office computer.

Back up new software immediately after installation and use the backup copy whenever you need

to restore. Retain original distribution diskettes in a safe location. Learn about your computer

and the so%vare you use and be

able to distinguish between nor- mal and abnormal system activity.

If you suspect your system

contains a virus, stop using it and

get assistance from a knowledgeable individual.

In general, educating users

is one of the best, most costeffective steps to take, says

Steinauer. Users should know

about malicious software in general and the risks that it

22
More on Computer Security

Under the Computer Security Act of 1987, NIST is responsible for technical, nnanagement, physical,

and administrative standards and guidelines for the cost-effective security and privacv of sensitive information in federal computer systems. NIST

has published four new documents that federal agencies, and others, will find helpful in im- proving the security of sensitive information contained in computer systems.

A series of three guides addresses many of the computer security questions of executives,

managers, and users. A fourth publication is a

guideline to assist federal agencies in developing

computer security training programs. They are

available prepaid from the Superintendent of Documents, U.S. Government Printing Office,

Washington, DC 20402. Order by the following

titles and stock numbers: Executive Guide to

the Protection of Information Resources

(NIST SP 500-169), SN 003-003-02969-6, $1 .50; Management Guide to ttie Protection of Information Resources (NIST SP 500-170), SN 003-003-

02968-8, $1 .75; Computer Users' Guide to the Protection of Information Resources (NIST SP

500-171). SN 003-003-02970-0, $1; and Computer Security Training Guidelines (NIST SP

500-172). SN 003-003-02975-1, $2,50.

The first three guides also are available through the NIST Computer Security Electronic

Bulletin Board by dialing 301/948-5717 or 5718

from a terminal which has the following capabilities: ASCII; 300, 1200, or 2400 baud; 8 or 7 bits; even or no parity; 1 stop bit. After "CONNECT,"

strike the carriage return twice and the system will be accessed. NIST is encouraging organizations

to reproduce and widely distribute all four guides.

poses, how to use technical controls, how to monitor their systems

and software for abnormal activity, and what to do to contain a problem or recover from an

attack. "An educated user is the best defense most organizations

have," he says. A number of commercial

organizations sell software or services that may help detect or remove some types of viruses.

But, says Steinauer, there are many types of viruses, and new

ones can appear at any time. "No

product can guarantee to identify

all viruses," he adds.

To help deal with various

types of computer security

threats, including malicious

software, NIST and others are forming a network of computer

security response and information

centers. These centers are being

modeled after the SEI's Computer

Emergency Response Team

Coordination Center, often called CERT, established by the Defense Advanced Research

Educating users is

one of the best,

most cost-effective

steps to take.

Projects Agency (DARPA), The

centers will serve as sources of information and guidance on

viruses and related threats and

will respond to computer security

incidents. NIST develops security stand- ards for federal agencies and

security guidelines for unclassified computer systems. NCSC,

a component of the National

Security Agency, develops guidelines for protecting classified

(national security) systems. SEI, a

research organization funded by

DARPA, is located at Carnegie

Mellon University in Pittsburgh.

In addition, NIST recently has

issued guidelines for controlling viruses in various computer

environments including personal

computers and networks. Computer Viruses and Related

Threats: A Management Guide

(NIST Special Publication 500-

166) is available from the Superintendent of Documents, U.S. Government Printing Office,

Washington, DC 20402. Order by

stock no. 003-003-02955-6 for $2,50 prepaid.

by Jan Kosko

NIST Public Affairs Specialist

23
Performance of

Steels Exposed to

Rre Predicted

ow will structural steel behave during and after a fire? A new

equation developed by scientists at the National Institute of

Standards and Technology provides designers and engineers

for the first time with a way to find quickly many of the answers

to this complex question. The new equation can be used to

assess the damage to a steel structure exposed to fire, and it can provide

information for the design of new structures to improve fire performance.

The equation for predicting the performance of structural

steel during and after a fire was

developed by guest scientist and

physicist Anne Fields, working

with her husband, NIST metallurgist Richard Fields. Designed for use on personal

computers, the new equation predicts the performance of ASTM

A36 structural steel when it is ex- posed to fire for periods from

2 minutes to 8 hours over a

temperature range from 350 to 650 °C. This is the range of pri- mary interest to structural en- gineers and others concerned

with property loss and life safety.

A36 is the most commonly used

steel in the United States for buildings, bridges, and ships, as well as for other structures that are

fabricated with rivets, bolts, and

welds.

Even though steel is a non- combustible material, it can

bend, twist, and change shape

when it is exposed to intense

heat. Deformation can continue

after a fire as the metal cools. Anne Fields explains that an assessment of the deformation of structural steel requires an analysis of the various stresses, temperatures, and times involved in order to calculate the resulting

strains. Different types of strain are dominant under various

conditions. The strains that must be

considered include elastic, recoverable strains (the steel deforms due to stress, but after the stress is removed the material regains its shape); plastic, time- independent strains (the steel changes shape or size permanently when the stress exceeds a

particular value); and creep,

time-dependent strains (caused

by continuous stress over a period of time at elevated temperatures). In general, the higher the temperature, stress, or time, the greater the damage. Each type of

strain has its own formula in the

Fields' equation.

Even though steel

is a noncombustible

material, it can

bend, twist, and

change shape when

it is exposed to

intense heat.

The scientists developed the equation after investigating the

results of available tests on structural steel. They found that the

24
two most important sets of data on deformation beliavior were

for Australian AS A149 and

Japanese SS41 structural steels. These steels were found to be a

close fit to the ASTM A36

specification.

. . . an assessment

of the deformation

of structural steel

requires an analysis

of the various stresses,

temperatures, and

times Involved. . . .

An analysis of the foreign

databases by Anne Fields pro- vided behavioral information that was lacking in the ASTM specification, which contains data on

only yield stress. This is the lowest stress a steel can with- stand before it becomes plastic

and begins to deform. To develop

the new equation, information was required on the stress-strain behavior at various temperatures

and times. The new equation also has

been used to construct "deformation mechanism" maps to illustrate the dominant behavior of

steel at any given temperature,

time, and stress. Such maps can

be used to compare the performance of ASTM A36 structural steel with foreign materials. This infor- mation could be very helpful to U.S. steel exporters and contractors in foreign markets. The NIST research was sponsored by the American Iron and

Steel Institute (AISI). AISI is a

national organization of more than 50 industrial manufacturers and more than 1,300 individual members from various sectors of the

steel industry.

A report, Elevated Temperature Deformation of Structural Steel (NISTIR 88-3899), with the new equation and information on

the correlations between

measured and predicted strains

for ASTM A36, Australian AS

A149, and Japanese SS41 structural steels, is available prepaid

for $21.95 from the National Technical Information Service,

Springfield, VA 221 61 . Order by

PB#89- 172621 /AS. R.R.

Guest scientist Anne Fields and NIST metallurgist Richard Fields discuss a deformation mechanism map, which illustrates the dominant behavior of steel

at a given temperature, time, and stress.

25
Model To Fight

Fire Deatiis, Costs

he National Institute of Standards and Technology has released

HAZARD I, a unique analysis method and computer program

that promises to revolutionize fire-safety practices and lead to

marked reductions in fire losses and costs. The culmination of

6 years of development by the NIST Center for Fire Research,

it is the first such comprehensive use of fire modeling in the world.

"HAZARD I represents the tre- mendous strides that have been

made in measuring fire hazard

ar>d safety. We're hoping it launches a revolution in how fire

is thought about, planned for, and

confronted," says Jack Snell, director of the NIST center. Each year, fires in the United

states cost nearly 6,000 lives, nearly 90,000 injuries, and billions

of dollars in direct property damage—one of the worst fire-loss records in the industrialized world. The total cost in the United

States of fire losses and fire protection is nearly $50 billion a year. HAZARD I can be used on a

personal computer to predict the hazards to occupants in a burning building and the change in hazard that will result if certain products, such as furniture, are changed in design or composition. "The user picks the building, the fire, the object burning, and

the people in the building, and

the computer does the rest," says Richard Bukowski, manager

for technology transfer in the center, who has led the program's

development.

The software predicts the temperature and smoke and toxic gas concentrations in each room

of the building as well as the behavior and movement of the build- ing occupants and the ultimate outcome of the fire. "The program

predicts who will be able to escape, who will become in- capacitated and who will die.

If it predicts someone will die, HAZARD I can determine where

the person will die and from

what," says Bukowski. "This infor- mation should provide better, more cost-effective strategies for reducing fire losses," he adds.

HAZARD I incorporates the results of fire research conducted

over the past 15 years at NIST

and elsewhere. It is the first computer model to take into account

the complex combination of physics, chemistry, fluid mechanics,

heat transfer, biology, toxicology,

and human behavior that deter- mines the outcome of a fire. To help transfer this new tech- nology to the fire protection community, NIST is working with several organizations. For ex- ample, the National Fire Protection Association (NFPA)

has agreed to distribute the HAZARD I package. NFPA is a

private, nonprofit organization of more than 52,000 members and

is the nation's principal source of voluntary consensus fire codes

and standards. "NFPA sees HAZARD I as an important new

tool that may have great use in protecting people and their property from fire, which is the mission

of NFPA," says Robert Grant,

NFPA president.

In addition, Bukowski is working with the Center for Firesafety

Studies at Worcester Polytechnic

Institute to develop training pro- grams to help users become

familiar with HAZARD I. Bukowski sees HAZARD I being used in a variety of ways in

fields ranging from fire investigation and reconstruction to fire protection engineering to product

development, manufacturing,

26
marketing, and arclnitectural design.

He hopes that one of the major uses of HAZARD I will be to help code developers like NFPA

and building and fire code officials deal more easily with new

materials or design and construction techniques. Fire safety in the United States is enforced through

state and local codes intended to provide time for people to evacuate safely. "Time is the critical

factor," says Bukcwski. "Having

3 minutes for safe escape when

10 are needed results in disaster. But providing 30 minutes of protection when 10 are needed can

lead to higher construction and

operating costs." The codes have not been able

to address directly these compari- sons between time required for escape and time available for escape because no model or other source of sound information has been available to make the necessary calculations. The experts who develop codes have

had to rely upon more limited sources, such as test methods

that examine specific fire properties or performance characteristics of a product. They used

their own judgment to fill in any

gaps. Because no model existed

to show how these different characteristics combined in a real fire, code developers had to deter- mine acceptable safety margins

for each product characteristic. With HAZARD I, code devel- opers can see how a product's

characteristics affect a fire. And,

they can see how modifying the product will change not only the

results of laboratory tests but also the critical time available for escape by building occupants.

"NFPA sees HAZARD I as an important new

tool that may have

great use in

protecting people and

their property

from fire. ..."

The need still exists for expert

judgment in using the model and

interpreting its results, but the codes developers and codes

officials will have much more help

with HAZARD 1. By realistically estimating

product performance, HAZARD I also should permit the codes to be adjusted more easily to new

materials, designs, products, and

technology. A nontraditional fire- safe product may have its per- formance "proven" on the computer. "With a tool like HAZARD I, new technology can be evaluated

cost-effectively and its likely impact on fire safety can be

determined before a performance

record is established through

use," says Bukowski.

Bukcwski envisions an even

broader range of uses in the future, including training firefighters

or planning how to fight a fire in a

particular building. HAZARD I also could be used by educators

to teach children about fire safety

and homeowners to plan escape

routes and make their homes

more fire-safe.

While some studies to validate

the models and procedures have

been conducted and the system

has been tested by NIST and out- side groups, Bukowski cautions

that it is a prototype and does

have limitations. HAZARD I can

be used reliably to model up to

six rooms in a building similar in size and construction to a singlefamily residence. However, not enough is known yet about how

smoke and toxic gases move

through heating, ventilating, and

air-conditioning (HVAC) systems

and tall shafts and stairways to model larger buildings. "In a fire, a building's HVAC system may

distribute fire products to some

parts of the building faster than

the fire alone would," says

Bukowski. However, other NIST

researchers are studying smoke

movement by HVAC systems.

This data will be included in a fu- ture version of HAZARD I and

will allow modeling of multi-story

occupancies.

"This is just the beginning for HAZARD I," says Bukowski. "As

the research continues and we

get more data, we'll continue to revise and refine the program,"

he adds.

A three-volume report and a

set of computer disks containing

the software necessary to conduct a hazard analysis are availa- ble for $225 from the National Fire Protection Association, One Stop Data Shop, Batterymarch Park,

Quincy, MA 02269 or the National Technical Information Service,

Springfield, VA 22161 . Use order

number PB 89-215404 when

ordering from NTIS. J.K.

27
Data, Anyone?

esearchers at General Dynamics Corp. faced a problem:

They needed to know how certain materials would perform

as shielding on the outside of spacecraft such as the shuttle.

In particular, these researchers were investigating how a

substance known as amorphous carbon would act under

the tremendous heat spacecraft are exposed to upon re-entering the

atmosphere. At what temperature

would the material evaporate? To

help solve the problem, the General Dynamics researchers

called on NIST's Standard Refer- ence Data (SRD) program.

Various researchers had

published data on the thermodynamic properties of amorphous

carbon at more earthly temperatures, while others had published more complete tables for carbon

in the form of graphite. SRD experts investigating the situation discovered that at high temperatures, amorphous carbon acted

enough like graphite that the General Dynamics researchers

could use the published graphite

data for their study.

In another example, re- searchers at the U.S. Army's

Aberdeen Proving Ground

enlisted the help of the SRD pro- gram. The Army needed to dis- pose of batches of a hazardous

warfare chemical called Lewisite. They wanted to burn it but they

had no idea how much heat the dangerous chemical would give

off. Would it explode? The Army

researchers got the information they needed from SRD experts

to safely burn the unwanted

chemical.

In many such cases, the NIST

Standard Reference Data pro- gram supplies data to scientists and engineers in industry, aca- demia, and the military. SRD experts often advise researchers

faced with incomplete, questionable, confusing, or conflicting data.Over the years scientists have

disseminated stacks of tables and lists of values ranging from

the heat capacity of liquid helium

to the fracture toughness of alu- minum alloys.

"We go out to find

what data will help

improve industries'

competitiveness down

the road. ..."

SRD experts cull the most reli- able data from the published lit- erature. Top-rate specialists assess the stock of existing data

and skim from it manageable,

trustworthy lists of figures

values industrial technologists

need for particular applications.

Researchers from the SRD

program keep up on the latest trends in data. The staff confer

with industry representatives to decide which data will be needed

for the coming months. As tech- nology changes, industries may come to require new figures for the radiation levels from nuclear waste products, the atmospheric

reactions of ozone-layer safe refrigerants, or the burning power

of alcohol-based fuels. "We go

out to find what data will help im- prove industries' competitiveness

down the road," says Malcolm

Chase, acting chief of the NIST

SRD program. Once they set out to produce

a needed set of data, SRD experts must "critically evaluate" existing data on the topic. To do

this, they check the methods the

original scientists used to obtain

their figures and test how well trends in the data follow known

physical and chemical laws. Much of this data assessment

goes on in approximately 20 data

centers, where groups predominantly made up of NIST scientists work on 3- to 7-year projects pro- ducing data with broad applications. In addition, NIST scientists

28
join with industry and university re- searchers on shorter term, 1- to 3-year data projects fulfilling more specific data needs.

All the studying and sorting

done through these data centers and data projects culminate in either journal articles or computerized databases. Because the SRD program caters to a variety

of customers, the researchers must create a product that people without specific expertise can use easily. SRD experts package their data either as clearly

documented journal entries or in user-friendly software databases

that customers can read on a per- sonal computer.

Some of these databases

simply allow the user to search

through large volumes of data. One lists 39 properties of the

1 ,023 most important industrial chemicals. Other databases actually calculate desired values. In the database called MIPROPS, a

user might, for instance, punch in pressure and temperature for a

substance, say a hydrocarbon,

and receive information on density, viscosity, and other key

properties.

The SRD program provides

data in three major areas: physics, chemistry, and materials. Much of the physics data help

scientists doing spectroscopy

the identification of atoms or molecules according to the frequencies of light they emit. An

energized atom or molecule gives

off its own unique spectrum of frequencies as its electrons make

jumps in energy, which return the atom or molecule to an unenergized state. Scientists use spectroscopy to determine the compositions of high-temperature

plasmas—ionized gases that make up stars as well as the

starting materials for nuclear fusion. For such studies, scientists need tables listing which frequenResearch chemist W. Gary Mallard (left) and John Herron, head of the NIST

chemical kinetics data center, demonstrate the chemical kinetics database.

cies identify with which atoms

and molecules.

Other physics aata describe

how much energy x rays and

gamma rays lose when passing

through various materials and

how different elements react chemically when their electrons are boosted to excited energy

states. Applications range from

designing radiation shielding for medical equipment to monitoring

acid rain. The chemistry data centers supply data on the properties of chemicals—how they melt, vaporize, and dissolve in various

fluids. Chemical data also describe how different chemicals

react—how readily they react, how fast, what products form,

how much energy is needed to

fuel the reaction, and how much

heat is released. In addition, the same spectroscopy data

used by physicists help chemists analyze the composition of materials. Data on metals, ceramics,

and polymers are furnished by re- searchers in the materials data

centers. The SRD program pro- vides computer databases and

published tables describing how

these materials bend, break, cor- rode, melt, and mix together. SRD

scientists work with researchers

from industrial societies, such as

the American Ceramics Society

and the National Association of Corrosion Engineers, as well as government agencies, including the Department of Energy and the

National Science Foundation. Together they undertake cooperative data programs of special

interest to industries. F.F.

29
NewPublications

International Cooperation and

Competition in Materials Science

and Engineering

Schwartz, L.H. and Schneider, S.J., Natl.

Inst. Stand. & Tech. (U.S.), NISTIR 89- 4041, 277 pages (June 1989). Order by

sending a self-addressed mailing label

to Samuel Schneider, NIST, B309 Materials BIdg., Gaithersburg, MD 20899.

Materials experts from industry,

universities, and government

argue in a new report that the

national programs of other nations in technology development, related to materials science and engineering, have

made Europe and Japan fully competitive and, in some cases, able to surpass

the United States. The study on national comparisons was conducted by Panel 3

of the Committee on Materials Science

and Engineering commissioned by the

National Research Council. The report by

Panel 3, led by Lyie Schwartz, director of the NIST Materials Science and Engineering Laboratory, deals with many facets of materials science and engineering as

practiced in the United States and other

countries. It contains information from a survey of national programs for science

and technology and materials science

and engineering, and it elaborates on the

administrative structures to carry out research and development.

Electronic Publishing: Guide to Selection

Rosenthal, L.S., Natl. Inst. Stand. &

Tech. (U.S.), NIST Spec. Pub, 500-164,

37 pages (June 1989). Order by stock

no. 003-003-02938-6 from GPO, $2.50

prepaid.

Electronic publishing offers many

pluses when it comes to producing documents and publications:

reduced costs, increased productivity,

and improved document quality. But these potential benefits can be realized

only if the system chosen is appropriate

for the organization and is installed and

managed properly. NIST researchers

have developed guidelines to help

managers and users make informed deci- sions on which systems are best for them. The guide is designed to acquaint

the reader with the many choices and implications associated with selecting and

using electronic publishing systems.

Specifications, Tolerances, and

Other Technical Requirements for

Weighing and Measuring Devices

Oppermann, H.V., editor, Natl. Inst. Stand. & Tech. (U.S.), NIST Hdbk.

44-1990, 275 pages (September 1989).

Order by stock no. 003-003-02964-5

from GPO, $16 prepaid.

This handbook has been revised by

NIST to reflect changes adopted

at the 74th Annual Meeting of the

National Conference on Weights and

Measures (NCWM) held in July 1989. NCWM is an organization of state, county, and city weights and measures

enforcement officials, which was established in 1905. NIST, which is a nonregulatory agency, provides technical support to NCWM through its Office of Weights and Measures. The major changes in this handbook include a revised section on liquid

measuring devices that establishes a re- quirement for equipment capable of computing the cash/credit pricing of retail motor fuel. NCWM also adopted a specifi- cation permitting the use of electronic data audit trails as security seals for electronic devices that are to be considered

the equivalent to the physical sealing of other devices with lead and wire seals or pressure-sensitive seals.

Uniform Laws and Regulations

Brickenkamp, C.S. and Koenig, J., editors, Natl. Inst. Stand. & Tech. (U.S.), NIST Hdbk. 130-1990, 172 pages

(October 1989). Order by stock no. 003-

003-02962-9 from GPO, $10 prepaid.

This handbook was revised by NIST

to reflect changes made at the 74th Annual Meeting of the National Conference on Weights and

Measures. A new regulation was

adopted for the maximum allowable variation (MAV) for polyethylene sheeting. In- dividual packages of poly sheeting cannot be short weight or short in thick- ness by more than an MAV of 4 percent

of the labeled weight or thickness. There

also is a revision to the Uniform Regulation for the Method of Sale of Commodities that covers stuffed items such as

meat, fish, seafood, and poultry as combination foods. The quantity repre- sentation may be in terms of the total weight of the product or combination,

and a quantity representation need not be made for each element provided that a list of the ingredients in order of their predominance by weight is shown on the

label. The handbook also contains a new

method of sale requirement for home liq- uid oxygen used for respiration.

Materials Science and

Engineering Laboratory

Natl. Inst. Stand. & Tech. (U.S.), 24

pages (August 1989). Order by sending a self-addressed mailing label to the

Materials Science and Engineering

Laboratory, NIST, B309 Materials BIdg.,

Gaithersburg, MD 20899.

Scientists in the NIST Materials Science and Engineering Laboratory are investigating the relation- ship between the structures and

properties of materials, then applying the

information to problems related to the design, processing, and performance of

30
advanced ceramics, polymers, and

metais. The research is focused on im- proving the understanding of materials processing to meet the needs of U.S. in- dustry. In the area of automated process

control, the goal is to help industry

develop real-time, automated systems

for the intelligent processing of materials

that emphasize product quality throughout the manufacturing process, rather than at the end of the line.

Guideline for \Nork Station Design

Rubin, A. and Gillette, G., Natl. Inst. Stand. & Tech. (U.S.), NISTIR 89-4163,

151 pages (September 1989). Order by

sending a self-addressed mailing label

to Arthur Rubin, NIST, A309 Building Re- search BIdg., Gaithersburg, MD 20899.

The computerized work station often is considered the key to in- creased office productivity. Yet, work station furnishings and layout sel- dom are given the same attention and re- sources as the technology. To help

managers make intelligent choices, NIST

researchers have developed a process

for designing work stations based on

office activities, including reading and

writing, talking on the telephone, drafting

and drawing, or using a video display

terminal. Work station dimensions and

configurations then are developed de- pending on the importance of the activity

and the time spent on it.

Service Life of Concrete

Clifton, J.R. and Knab, L.I., Natl. Inst. Stand. & Tech. (U.S.), NISTIR 89-4086,

151 pages (June 1989). Order by stock

no. PB 89-215362/AS from NTIS, $21.95

prepaid.

In

a study for the U.S. Nuclear Regulatory Commission (NRC), NIST re- searchers are attempting to determine

if concrete can be formulated to last up to

500 years. The NRC is responsible for developing a strategy for storing lowlevel radioactive waste. One approach

being considered by NRC involves stor- ing radioactive wastes in underground

concrete vaults that will be required to

last 500 years. NIST researchers analyzed the major degradation processes

likely to affect the vaults and recom- mended ways to predict the service life of concrete. Based on available knowl- edge, they concluded it seems likely that concrete can be formulated which

should have a service life of 500 years

in the expected environments. NIST

cautions that such a lifetime can be

achieved only if the concrete materials meet carefully defined specifications

and good construction practices are

followed.

Sensors and Measurement

Techniques for Assessing

Structural Performance

Proceedings of an International

Workshop

Marshall, R.D., editor, Natl. Inst. Stand. &

Tech. (U.S.), NISTIR 89-4153, 66 pages

(August 1989). Order by stock no. PB 89- 235865 from NTIS, $15.95 prepaid.

Reliable, economical devices are needed to measure the behavior

of structures during events such

as earthquakes or strong winds or to assess the day-to-day condition of a

structure. At present, field measuring devices tend to be costly and need almost

constant monitoring as well as frequent

equipment servicing and calibration. In some cases, they produce questionable

data or malfunction during critical events such as earthquakes. In a meeting held

last fall, experts from around the world

convened at NIST to discuss these

problems and some new materials and

improved technology that could have a

dramatic impact on the reliability and

versatility of measurement devices. In addition, the experts formulated recom- mendations for future research.

False Alarm Study of Smoke

Detectors in Department of

Veterans Affairs Medical Centers

Dubivsky, P.M. and Bukowski, R.W., Natl.

Inst. Stand. & Tech. (U.S.), NISTIR 89- 4077, 234 pages (May 1989). Order by

stock no. PB 89-193304/AS from NTIS,

$15.95 prepaid.

Overthe past few years, the problem of false alarms from smoke

detectors has been growing in large buildings, such as health care facilities. NIST and Underwriters Laboratories,

Inc., recently studied smoke detector

false alarms in 133 Department of Veter- ans Affairs Medical Centers (VAMC's).

The researchers determined that two

principal factors play a major role in the

rate of false alarms: the design and sensitivity of the detector and the testing,

cleaning, and operational procedures at the VAMC's. They found that the ratio of false alarms to real alarms was about 16

to 1 and that about half of the total number of false alarms is related to smoking.

Among the numerous recommendations,

the one that should have the greatest im- pact say the researchers, is strictly enforcing policies regarding designated

smoking areas.

Ordering Information

To order publications from NTIS, send re- quest with payment to: National Technical Information Service, Springfield, VA

22161 . Publications can be ordered from

GPO by mailing the order with payment

to Superintendent of Documents, U.S. Government Printing Office, Washington,

DC 20402.

31
Conference Calendar

Workshop on Electrical

Measurement Assurance

Programs

Inn at the Airport, Tucson, AZ

This workshop will provide in-depth train- ing for those involved in d.c, and low- frequency electrical measurements. Participants will receive instruction based on

calibration design methods and statisti- cal quality control techniques used at NIST. Participants will learn how to establish and maintain rigorous quality control programs in their own laboratories to en- sure the accuracy of electrical measurements. Sponsored by NIST. Contact: Joe

Simmons, NIST, B360 Physics BIdg.,

Gaithersburg, MD 20899, 301/975-2002.

International Conference on CIM

Architecture (CIMCON '90)

NIST, Galttiersburg, MD

Much has been learned from the initial implementation phases of early

computer-integrated manufacturing

(Clfvl) programs. CIMCON '90 will pro- vide a forum for people to describe their original architectures and implementation

plans, to discuss what did and did not work, and to report on changes they

might be considering in those architec- tures and plans. This conference will give

those responsible for CIM architecture the opportunity to discuss standards

needs with experts from around the world and to learn about the problems

involved in integrating new and existing

manufacturing systems. Sponsored by

NIST, the Navy Manufacturing Technology Program, the U.S. Air Force WRDC/MTI, and the University of North

Carolina at Charlotte. Contact: Albert Jones, NIST, B124 Metrology BIdg.,

Gaithersburg, MD 20899, 301/975-3554.

Fiftieth Annual Conference on Physical Electronics

NIST, Gaithersburg, MD

The physics and chemistry of solid sur- faces and interfaces will be addressed at

this conference. Topics will include electronic, chemical, and crystallographic

properties of surfaces and interfaces as

well as kinetic and dynamiic mechanisms

of physical and chemical reactions,

phase transitions, and adsorption. The

properties of surfaces that are clean or

that incorporate foreign atoms are also of

interest, as are new methods of surface

analysis and characterization. Emphasis

will be placed on the description of sur- face and interface properties at a fun- damental atomic and molecular level. Sponsored by the American Physical

Society, NIST, and the University of Maryland. Contact: Richard Cavanagh,

NIST, B248 Chemistry BIdg., Gaithersburg, MD 20899, 301/975-2368.

Conference on Advances

in Cementitious Materials

NIST, Gaithersburg, MD

This conference will be of interest to all concerned with enhancing the perform- ance of concrete and making it a more

predictable material. The purpose is to advance understanding of cementitious

materials to provide a rational approach

to the design of new cementitious materials and composites. The fundamental

science underlying the behavior of all cementitious materials will be addressed;

however, to limit the scope of the confer- ence, degradation processes will not be

included. Session topics include characterization of particulate starting materials and of resultant microstructure; physical

and chemical phenomena in the flow of cementitious materials prior to hardening; relationships between microstructure

and physical and mechanical behavior;

interactions of water with the hardened

cement paste matrix; and the microstructure and micromechanics of cementitious

composites. Participants will be able to

visit the laboratories of the NIST Center

for Building Technology. Sponsored by

NIST and the American Ceramic Society. Contact: Geoffrey Frohnsdorff, NIST,

B368 Building Research BIdg., Gaithersburg, MD 20899, 301/975-6706.

International Conference on the Chemistry of Electronic

Ceramic Materials

Grand Teton National Park, WY

Materials chemistry has evolved from the more identifiable disciplines of inorganic

and solid state chemistry, ceramics, and

materials science. This conference will bring together major national and inter- national researchers to bridge the gap

between those primarily interested in the pure chemistry of inorganic solids and

those interested in the physical and electronic properties of ceramics. One of the primary goals of the conference will be to evaluate the current understanding of the chemistry of electronic ceramic materials and to assess the state of a field that has

become one of the most important areas

of advanced materials research. Sponsored by NIST, the Office of Naval Research, and federal, university, and in- dustry scientific organizations. Contact: Robert Roth, NIST, B126 Materials BIdg.,

Gaithersburg, MD 20899, 301/975-6116.

32 1>U.S. GOVERNMENT PRINTING OFFiCEi 199 0-= 265-9^3 /00J2S

U.S. DEPARTMENT OF COMMERCE

National Institute of Standards and Technology

Gaithersburg, MD 20899

OFFICIAL BUSINESS

Penalty for Private Use, $300

BULK RATE

POSTAGE & FEES PAID NIST

PERMIT No. G195