Shorts
Co-op Corner :
Radiation and Hearts, Chip Measurements, Fat Content, Aircraft Fires
NIST's Manufacturing Extension Partnership, now in its seventh year of
operation, has been steadily adding new centers to help the nation's
smaller manufacturers get the technology and business advice they need
to stay competitive. The program manages a network of about 60 centers
in 42 states and Puerto Rico.
A new set of more than 50 case studies helps illustrate how the centers
-- which are co-funded by NIST with state and local organizations --
provide services that help client companies modernize their operations,
improve quality, and increase profitability. Examples of typical
benefits reaped by small companies with assistance from their local MEP
centers are:
- TECSTAR Inc., City of Industry, Calif. -- saved $3 million annually by
improving handling and processing of solar cell wafers, resulting in
less breakage, reduced downtime, and improved cycle time;
- Miller Metal Fabrication, Harrington, Del. -- redesigned its shop
layout, which allowed the company to cut labor costs in half while
reducing prices;
- Clay & Bailey, Kansas City, Mo. -- reduced worker injuries fourfold,
reduced compensation insurance by $100,000/year, reduced costs, and
improved customer satisfaction; and
- Breezewood Inc., Reynoldsville, Pa. -- implemented Just-in-Time
inventory control and improved employee training that cut cycle time by
50 percent, decreased assembly line downtime due to parts outages from
25 percent to 5 percent, and increased capacity by 20 percent.
To receive a packet of MEP success stories, contact MEP, (301) 975-5020.
After several years of concerted research, NIST is now the proud owner
of the world's most accurate electron counter. An outgrowth of NIST's
work to find better ways to determine capacitance (a measure of a
capacitor's charge-holding ability), the counter can place 70 million
electrons on a capacitor with an uncertainty of just one electron.
The heart of the counter is a special microcircuit that "pumps"
electrons one at a time to a capacitor. In the atomic force micrograph
above, the bullet-shaped regions in the center are micrometer-sized
islands of aluminum, separated by tiny "tunnel junctions" of aluminum
oxide (yellow dots). The capacitance of the islands is so small that at
temperatures near absolute zero (less than 0.1 Kelvin) only one excess
electron can occupy a given island at a time. An electron is moved from
island to island through the tunnel junctions, which act like turnstiles
allowing only one electron to get through at a time.
Reliable electron counting turns out to have several practical
scientific benefits. By knowing exactly how many electron charges are
placed on a capacitor and then carefully measuring the voltage, the NIST
researchers will be able to measure capacitance directly. NIST's primary
capacitance standard -- as required by the current international
definitions of electrical quantities -- is a mechanical device. The
availability of a very accurate measure of capacitance based on
fundamental, "intrinsic" quantities should allow high-tech companies and
other research laboratories to increase greatly the accuracy of their
electrical measurements.
The new counter also may help researchers improve determination of the
"fine-structure constant," a key value needed to better test predictions
of quantum electrodynamics and a "holy grail" for many physicists and
metrologists. The fine-structure constant is an absolute physical
quantity related to the strength of an atom's electromagnetic forces. It
is to physics and metrology what pi is to spherical geometry -- the
better you know it the more accurately you can calculate a whole range
of other important quantities.
Contact: Mark Keller, (303) 497-5430.
An inexpensive acoustic wave transducer developed by NIST mechanical
engineers soon may make it easier for researchers to decide if new
composite materials or film coatings have the right mechanical
properties for specific applications.
The transducer sends a pulsed sound wave through a test sample that is
submerged in water. The speed of the reflected wave provides a measure
of the material's elasticity (its ability to flex under stress), while
the direction of the reflected wave provides details about crystal
planes or defects within the material.
Current acoustic microscopes use "lenses" and may cost hundreds of
thousands of dollars. The NIST device uses off-the-shelf parts costing
less than $20,000, yet can provide similar information about materials'
properties. Rather than use a lens, the NIST instrument uses a curved
transducer made with an inexpensive piezoelectric, plastic film.
Electrical signals cause the film to emit relatively low frequency,
pulsed sound waves. The curvature of the film focuses the sound waves in
the same way that curved mirrors are used in telescopes to focus light
from distant stars. The transducer is positioned above the sample and
then scanned or rotated through different angles to get a full picture
of the material's elastic properties.
The graphic above shows a composite image made by rotating the
transducer above a sample of single-crystal silicon. The broken "V"
wavefront is characteristic of silicon's cubic crystalline planes. The
technique also will allow researchers to spot surface and subsurface
defects in a variety of metallic or composite materials. One
particularly promising application may be the inspection of novel films
such as ceramic coatings on metal to predict their reliability under
various conditions.
Contact: Nelson Hsu, (301) 975-6630.
They say, "You can't be in two places at one time." They may be wrong,
however. NIST scientists have succeeded in preparing a beryllium atom
that is simultaneously located in two widely separated places.
The feat was accomplished by cooling a single beryllium ion (with one of
its two outer electrons stripped away) to almost absolute zero in an
electromagnetic trap and then coaxing it into two distinct internal
quantum states at the same time. While others have observed atoms in
"super-imposed" internal quantum states, the NIST researchers went one
better by delicately applying laser pulses to physically separate the
two states by more than 80 nanometers, or 11 times the size of the
original ion.
The graphic above shows an idealized view of the atom's positions. Each
colored strip in the graphic represents a particular snapshot in time.
It's like having a marble that is somehow simultaneously on opposite
slopes of a bowl. The atom starts out in two widely separated places at
the same time (two blue peaks in foreground). As time progresses, it
moves "through itself" to the bottom of the "bowl" (red peaks), then
splits to return to opposite sides of the "bowl."
In 1935 both Albert Einstein and Erwin Schroedinger described scenarios
like the NIST experiment that are predicted in quantum mechanics but
seem to defy reality. Schroedinger, for example, considered the
possibility that a cat could somehow be prepared to be both dead and
alive at the same time. "Schroedinger's cat" soon became shorthand for
superimposed quantum states.
The NIST team verified that the cat state was produced by repeating
their experiment many times while varying the direction the laser pulses
gently push the two states apart. For certain directions, the
researchers detected an interference pattern -- a series of bright and
dark lines showing that the ion's wave (all atoms are both particles and
waves) was actually superimposed on itself rather than flipping from one
location to another. Widely separated states produced narrower
interference lines than more closely spaced states. The effect is
similar to shining a flashlight through a piece of cardboard with
cut-out slits. Widely spaced slits produce a different interference
pattern than closely spaced ones.
The NIST researchers hope their work will lead to better atomic clocks.
It also may be useful in development of quantum computers and quantum
cryptography.
Contact: Chris Monroe, (303) 497-7415.
Manufacturers of jet turbine blades often can't tell if a blade has been
"cooked" right until they remove the mold and take a look.
Working in collaboration with engineers at Howmet Corp., Whitehall,
Mich., NIST researchers have developed an X-ray sensor that they hope
will take some of the guess work out of turbine blade technology. The
instrument sends high-energy X-rays through a casting mold while a part
is being made. By detecting the diffraction (change in direction) of the
X-rays on the other side of the mold, the researchers can monitor in
real-time the solidification of a molten metal into its crystalline
state.
Ordinary solid metal objects contain a crazy quilt of crystals that grew
at many different angles. Turbine blades, on the other hand, are often
solidified in special "temperature gradient" furnaces that cool the
molten alloy down slowly enough so that a single crystal grows from one
end of the blade to the other. The lack of crystal boundaries makes
these single-crystal turbine blades stronger and more resistant to high
engine temperatures. The graphics above show the X-ray diffraction
patterns produced with multicrystalline metal at room temperature (far
left); liquid, non-crystalline molten metal (center); and a fully
re-solidified crystal.
The NIST system should allow manufacturers to optimize their processes
so that they consistently grow single-crystal blades in the shortest
amount of time.
Contact: Thomas Siewert, (303) 497-3523.
NIST's homepage on the World Wide Web -- http://www. nist.gov -- got a
facelift recently. The site was redesigned and several new sections were
added. Specific NIST programs also have been improving their WWW pages.
Some highlights:
- The NIST Physics Laboratory -- http://physics.nist.gov. Has a variety
of physical reference databases, including a popular site providing
recommended values for fundamental physical constants.
- Manufacturing Extension Partnership -- http://www.mep.nist.gov. Also
revamped and expanded in the last few months.
- Guide to Available Mathematical Software -- http:// math.nist.gov/gams.
A cross index and virtual repository of some 10,000 computer programs of
use in computational science and engineering.
- Fire on the Web -- http://www.fire.nist.gov/. A repository of
links to fire related software, experimental data, movies, and even an
online program for running your own one-room fire scenario.
NIST-developed software recently earned "two thumbs up" from a special
effects company that created scenes for Babe, the popular movie about a
talking pig. The movie won an Academy Award for visual effects that
included realistic computer-generated background scenes and simulations
of animal mouths talking. Rhythm & Hues Studios of Marina Del Rey,
Calif., cyber-crafted the scenes, then sent the massive graphics files
electronically to the film's Australian production site, 11,200
kilometers (7,000 miles) away. Rather than waste lots of staff time
monitoring every transfer, the company used a NIST software tool called
"Expect" to help watch the process and automatically resend scenes that
failed to make the trans-Pacific journey in one piece. The software
allows computer operators to write relatively simple programs that
recognize error messages, password prompts, or other recurring messages
and then perform the keystrokes a human operator would normally do next
to keep the process going. Systems administrators and others charged
with such repetitive computer chores commend the publicly available
software for simplifying and speeding hundreds of programming jobs and
computing applications. Contact: Don Libes, (301) 975-3535.
When the ball drops on Times Square to mark the start of the year 2000,
NIST computer experts hope U.S. companies will be ready with computer
hardware and software that uses 8-digit, yyyy/mm/dd, date codes rather
than current 6-digit coding systems. The scope of the potential problems
from 6-digit coding is enormous. An accounting system, for example, that
assigns the year 2000 a date code of 00 may balk at printing checks that
appear to have no assigned year. Electronic financial systems that
transfer more than a trillion dollars a day may no longer work.
Computer clocks will go haywire, unable to decide what date comes after
no date. The cure for the problem, say NIST researchers, is for
organizations to take steps now to assess how large a problem 6-digit
date code formats will be for their particular organization, plan for
the necessary modifications for custom-made software, and budget for
replacement or upgrading of off-the-shelf software and hardware no later
than 1999. This will allow enough time for testing and possibly
debugging new systems before the critical day arrives. Contact: Gary Fisher, (301) 975-3275.
That's "GI" as in gastrointestinal, and the "bad guys" are viruses,
disease-causing organisms, bile acids made from cholesterol, or other
things in your digestive tract that you'd just as soon have keep passing
through. GelTex Pharmaceuticals Inc., a 33-person company based in
Waltham, Mass., has developed a polymer-based medicine designed to help
the body rid itself of such gastro baddies before they have a chance to
cause diarrhea, fat clogged arteries, and other unpleasantries. The
company currently is conducting clinical trials with a capsule form of
the medicine that selectively binds bile acids causing a decrease in LDL
(bad) cholesterol and with another capsule that helps kidney dialysis
patients maintain proper blood levels of phosphorus. With a three-year
award from NIST's Advanced Technology Program, the company now is
attempting to extend the technology to the treatment of human rotavirus,
which causes diarrhea in infants and toddlers, and to Cryptosporidium
parvum, a water-borne single-celled organism that caused 400,000
Milwaukee residents to become ill in 1993. The encapsulated polymer
expands in the stomach into tiny molecular "nets" designed to bind only
to a specific organism or molecule. The "nets" prevent the virus or
organism from reproducing in the gastrointestinal tract and instead
carry it through the intestines to be excreted. Contact: Amy Wilson,
(617) 290-5888.
A NIST-developed machine called the "Super Shaker" could ironically help
the world run a little more smoothly. Developed with funding from the
U.S. Air Force, the new machine is designed to double the accuracy of
NIST's current accelerometer calibrations. Accelerometers are electronic
sensors that detect changes in speed and direction. They are used in
aircraft and cars to sense changes in speed and in computer disk drives
and cargo containers to measure vibration (i.e., man-handling during
shipment). They also are key components for activating airbags, which
inflate with rapid deceleration. NIST calibrates the reference
accelerometers used by companies and research laboratories to check the
accuracy of accelerometers in products. NIST is collaborating with Booth
Development Inc., Short Beach, Conn., on the new automated machine. It
can perform two types of calibrations previously requiring different
machines and will operate over a wide range of frequencies. Contact:
Beverly Payne, (301) 975-6639.
Radiation and Hearts--Balloon angioplasty has helped thousands of
heart patients avoid bypass surgery. About one-third of the procedures
have to be repeated, however, because the stretched artery walls scar
and reclose. Tiny radioactive seeds made by Novoste Corp., Atlanta, may
provide a way to limit such scarring. The seeds are delivered through a
small catheter to the artery where they irradiate only the target artery
wall. NIST physicists are developing ways to calibrate the radiation
dose delivered by the seeds so that researchers can evaluate the value
of the new therapy for angioplasty patients. Contact: Christopher Soares, (301) 975-5589.
Chip Measurements--Four companies and SEMATECH have joined NIST in a
new consortium to develop the measurement instruments needed to pack
more features into tomorrow's semiconductor chips. Corporate members
include Bio-Rad Laboratories, Digital Instruments, KLA Instruments, and
OSI. The Scanning Capacitance and Electromagnetic Sensor Consortium
plans to research new ways to measure accurately the relative location
or overlay of features placed on successive chip layers. Members will
compare the merits of two new overlay measurement methods -- scanning
capacitance probes and electromagnetic sensors. Contact: Michael Cresswell, (301) 975-2072.
Fat Content--To help ensure labels listing the fat content of foods
are accurate, NIST has collaborated with the U.S. Department of
Agriculture to prepare a new Standard Reference Material. The SRM
consists of four 15-gram bottles of frozen blended food typically
consumed in the United States. NIST chemists certified the
concentrations of cholesterol and six of the most abundant fatty acids
in the mixture. The new SRM also provides data for protein, moisture,
total fat, ash, carbohydrate, and calories. Food laboratories can use
the SRM to check the accuracy of their analysis instruments and methods.
Contact: SRM Program, (301) 975-6776.
Aircraft Fires--The same technology that automobile manufacturers use
to inflate airbags soon may save lives and property as a fire
suppressant. NIST researchers believe that solid propellant gas
generators -- essentially airbag inflators without the bag -- have great
futures as compact, environmentally friendly fire suppressant systems.
Recent tests performed at the Naval Air Warfare Center in China Lake,
Calif., and Wright Laboratory in Dayton, Ohio, have demonstrated the
feasibility of using such systems to suppress simulated aircraft dry bay
fires. Other uses might be in warehouses, industrial sites, race cars,
and ships. Contact: Jiann Yang, (301) 975-6662.
NIST is an agency of the U.S. Department of Commerce's Technology
Administration. NIST promotes U.S. economic growth by working with industry to
develop and apply technology, measurements, and standards. Technology at a
Glance is produced by the Public and Business Affairs Division, A903
Administration Bldg., NIST, Gaithersburg, Md. 20899-0001. Any mention of
commercial products is for information only; it does not imply recommendation or
endorsement by NIST. Technology at a Glance Editor: Gail Porter, (301) 975-3392, email:gail.porter@nist.gov. For patent information, call (301) 975-3084.
At A Glance, Spring/Summer 1996