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Nanotechnology
NIST, HP Move Toward
Critical Molecular Electronics Measurements
Researchers
at the National Institute of Standards and Technology (NIST)
and Hewlett Packard (HP) Laboratories will report this week that
they are progressing toward reliable methods for measuring the
electrical behavior of molecular electronic devices, an infant
nanotechnology eyed for future integrated circuits.
Using a “crossbar” test
structure consisting of a one-molecule-thick film (a monolayer)
sandwiched between a series of perpendicular metal
wires,
collaborators at separate facilities recorded nearly identical
electrical measurements. This step, along with others taken to
eliminate potential
sources of error, ensures that the measured behavior is directly
attributable to the device, and not the experimental set-up.
To be announced on April 2, 2003, at the GOMACTECH Conference
in Tampa, Fla., the accomplishment well may be the first
capacitance-voltage
measurements of a molecular-electronic device. These and other
measurements confirmed that the device functioned like a switch,
alternating between
different currents in response to different input voltages.
The
results also pose something of an enigma, says NIST physicist
Curt Richter. The two-state system is due to the presence of
the molecular layer, he writes with HP collaborator Duncan
Stewart. However, the molecular monolayer is not the
sole cause. Rather,
the researchers
say, the switch-like behavior is probably the result of an
interaction at the interface between molecule and the
wire
electrode.
Although several research groups have demonstrated single-molecule
devices in the laboratory, a suite of reliable measurement
methods are needed to move molecular-electronics technology
beyond the
proof-of-concept stage.
To read the paper
"Metrology for Molecular Electronics" by C.A. Richter and D. R.
Stewart, go to: http://www.nist.gov/public_affairs/richter.pdf. (Download
Adobe Acrobat Reader FREE)
For more information, contact Richter at (301) 975-2082 or curt.richter@nist.gov.
Media
Contact:
Mark
Bello, (301) 975-3776
Security and Safety
New Report
Details NIST Law Enforcement Activities
A new
report from the National Institute of Standards and Technology
(NIST) tells how its experts in fields ranging from forensic
science to communications
engineering have helped give the criminal justice and public
safety communities a technological helping hand.
Office
of Law Enforcement Standards: Programs, Activities and Accomplishments (NISTIR 6952) describes the research efforts
of the scientists and engineers
working in NIST’s Office of Law Enforcement Standards (OLES). Their projects
have ranged from improved testing of computer forensic tools to new standards
for stab resistant vests.
The report provides comprehensive descriptions of OLES activities
that will be of great interest to police and fire departments,
as well as other organizations
concerned with law enforcement. The six OLES program areas covered in the publication
are: weapons and protective systems; detection, inspection and enforcement
technologies; chemical systems and materials; forensic
sciences; public safety communication
standards; and critical incident technologies. Examples of projects detailed
within these chapters include the development of a performance standard for
armored cars, an evaluation of sweat-based drug testing
techniques, and advances in DNA
identification methods/standards.
NISTIR
6952 may be viewed at www.eeel.nist.gov/lab_office/documents.html (click on “2003 Technical Programs, Activities, and Accomplishments” and
then “Office of Law Enforcement Standards”). Single copies of
NIST IR 6952 are available by writing to Sharon Lyles, OLES, NIST, Stop 8102,
Gaithersburg,
Md. 20899-8102; or sending an e-mail to oles@nist.gov.
Information Technology
NIST Conference to Showcase
Latest in DVD Tech and Standards
Declining
prices and new software have combined to make DVD authoring tools
available to home computer users. The change is bringing capabilities
to home computer users that, as little as two years ago, were
affordable only to professional video producers. In addition,
private and public sector organizations are considering the use
of DVD to manage and preserve their digital assets.
DVDs are used increasingly in arenas ranging from instructional
training to preservation of massive amounts of digital
information. They also
are showing up as a replacement for VCRs in many American living
rooms and corporate offices.
The National Institute of Standards and Technology (NIST) and
the DVD Association (DVDA) are holding their fourth annual
inter-national
conference, DVD 2003, on June 9-11, 2003. DVD 2003 will allow
industry professionals to see firsthand how DVD technology—the premier
format for video, audio and data storage—is influencing a variety
of fields, including health care, finance and homeland security.
Topics for the three-day conference include: blue laser technology
and HD-DVD, the interactivity of simulations and games with
DVD, writable DVD standards and interoperability, the
role of DVD
in digital preservation, DVD usage in the federal government
and niche
markets.
In addition to the technical program, DVD 2003 will feature
short courses on DVD applications and vendor exhibits
showing the latest
in DVD authoring and replication tools.
DVD 2003 will be held at NIST headquarters in Gaithersburg,
Md. Due to heightened security at federal facilities, preregistration
is
required.
More information about the conference, including an online
registration form, is available at www.nist.gov/DVD2003.
Physics
NIST Researchers ‘Go
Dancing’ with Synchronized Lasers
Pulsed
lasers are like middle schoolers at a dance. You can put them
in the same physical space but they still don’t pair up
very well. Recently, however, National Institute of Standards
and Technology (NIST) researchers working at JILA (a research
and teaching institute operated jointly by the University of
Colorado at Boulder and NIST’s Boulder Laboratories) have
coaxed ultrafast pulsed lasers with different wavelengths not
only to match the timing of their pulses but also to lock into
the same “phase,” or cycle of peaks and troughs.
To extend the analogy, the NIST researchers have made unruly,
ultrafast lasers do the equivalent of two middle schoolers moving
in perfect synchrony like Olympic ice dancers.
The technique provides an important new tool for studying the
motions and vibrations of atom groups within molecules.
By synchronizing
and locking the wave forms of two, sub-picosecond lasers together,
the NIST researchers have made a well-controlled, tunable source
of infrared radiation that can be used to precisely break specific
bonds or produce specific rotational or vibrational changes in
large molecules. The technique also may be useful for
transmitting ultraprecise
frequency signals and for mapping the chemical composition of living
cells with pulses so quick they do not damage the living tissue.
The ultimate goal of the research is to make an optical waveform
synthesizer that can create an arbitrary optical pulse on demand
and use this
tailored energy to control molecules and atoms
precisely.
For more information, contact Jun Ye, (303) 735-3171, ye@jila.colorado.edu.
NIST to Discontinue
Its Role in Satellite Time Dissemination
Since
1974, the time and frequency signals of the National Institute
of Standards and Technology (NIST) have been relayed to most
of the Western Hemisphere by two GOES (Geostationary Operational
Environmental Satellites) weather satellites operated by the
National Oceanic and Atmospheric Administration (NOAA). The signals
have been able to set clocks with suitable timing receivers to
within 100 microseconds (millionths of a second) of the Coordinated
Universal Time (known as UTC). However, most users of time signals
have switched over to those provided by Global Positioning Satellites
(GPS), which offer greater accuracy and a worldwide distribution.
As a result, GOES timing receivers have been off the market for
some time.
With the need for the satellite time service diminishing, NIST
and NOAA recently made a joint decision for NIST to discontinue
its involvement with the GOES program on Jan. 1, 2005. NIST will
continue to control and monitor the time code through Jan. 1,
2005, to allow users who require a high-accuracy signal
sufficient time
to replace their existing receivers.
NOAA plans to provide a GOES time code indefinitely after Jan.
1, 2005. Existing receivers should be able to continue to receive
and decode the time signal; however, the received time is expected
to be less accurate when NIST discontinues its involvement.
For
more information, contact Michael Lombardi, (303) 497-3212, lombardi@boulder.nist.gov.
NIST Seeks Comments
on Revised Standards for Wood Panels
The
National Institute of Standards and Technology (NIST) invites
public review and comment on draft Voluntary Product Standard
PS 2-02,
the proposed revision to PS 2-92, “Performance Standard
for Wood-Based Structural-Use Panels.” The standard
establishes criteria
for assessing the acceptability of wood-based
structural-use panels for construction sheathing and single-floor applications.
It also provides a basis for common understanding among the producers, distributors
and the users of structural panels, which include plywood, wafer board, oriented
strand board (OSB), structural particle board and composite board.
In addition to updating terminology and clarifying text,
the draft proposes revisions in the criteria and
methods for assessing the bond performance of OSB,
as well
as those for assessing linear expansion of all types of structural panels.
It also would revise structural performance descriptions
and would delete the stability
index and “exposure 2” method for evaluating bond performance.
The Standing Committee for PS 2 last revised the standard
in 1992. Responsible for maintaining, revising and
interpreting the standard, the committee is comprised
of producers, distributors, users and others with an interest in the standard.
The APA—also known as the Engineered Wood Association—is the document’s
sponsor.
Copies of the Final Draft Revision PS 2-02 and other related documents
are available at http://ts.nist.gov/ts/htdocs/210/sccg/ps2-92.pdf.
Comments on PS 2-02, supported by data, views or arguments, should
be submitted to NIST no later than April 28, 2003.
Upon completion of the review, the Standing Committee and
NIST will revise the standard accordingly.
Send comments to JoAnne Overman, NIST, 100 Bureau Drive,
Stop 2150, Gaithersburg, Md. 20899-2150. Electronic
comments may be submitted to joanne.overman@nist.gov.
Media Contact:
Mark
Bello, (301) 975-3776
Editor: Michael E. Newman
Date created: 4/1/2003
Contact: inquiries@nist.gov
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