April
12, 2005
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Probable
Cause Sequences for WTC Collapses Finalized
At
a press briefing in New York City on April 5, the National
Institute of Standards and Technology (NIST) presented its
analysis of how the World Trade Center (WTC) towers collapsed
after two aircraft were flown into the buildings by terrorists
on Sept. 11, 2001. The study is the most detailed examination
of a building failure ever conducted.
“Like most building collapses, these events were the result
of a combination of factors,” said Shyam Sunder,
lead investigator for the agency’s building and
fire safety investigation into the WTC disaster. “While
the buildings were able to withstand the initial impact
of the aircraft, the resulting fires that spread through
the towers weakened support columns and floors that had
fireproofing dislodged by the impacts. This eventually
led to collapse as the perimeter columns were pulled
inward by the sagging floors and buckled.”
The
probable collapse sequences update and finalize hypotheses
released by NIST last October. The sequences are supported
by extensive computer modeling
and the evidence held by NIST, including photographs
and videos, recovered steel, eyewitness accounts
and emergency
communication records. Additionally, this information
was used to document a variety of factors affecting
the performance
of the buildings, the efforts of emergency responders
and the ability of occupants to escape prior to the
collapses. In turn, NIST has identified a number
of future practices
and technologies that potentially could have enhanced
building
performance and life safety capabilities on 9-11
had they been available for implementation.
NIST also released drafts of 15 reports from three
projects of the investigation: analysis of building
and fire codes
and practices; occupant behavior, egress and emergency
communications; and fire service technologies and
guidelines.
Recommendations for improvements to building and
fire codes, standards and practices derived from
these and
the other
five projects in the investigation will be released
for public comment in June, along with the draft
of the final
investigation report and drafts of 27 reports
from the remaining five projects.
For
further information, see www.nist.gov/public_affairs/releases/wtc_briefing_april0505.htm.
Media
Contact:
Michael E. Newman, michael.newman@nist.gov,
(301) 975-3025
Light
Scattering Method Reveals Details under Skin
A
new optical method that can image subsurface structures under
skin has been demonstrated by scientists at the National Institute
of Standards and Technology (NIST) and the Johns Hopkins University
Applied Physics Laboratory.
The method relies on differences in the way surface and
subsurface features of various materials scatter light. It
was demonstrated with small pieces of pigskin and inorganic
materials but might eventually prove useful for imaging living
tissues to help diagnose or determine the extent of various
types of skin cancers. A paper on the work was presented
at a recent technical meeting and is in press.*
The imaging process involves illuminating a sample with
polarized light, which has its electric field oriented in
a particular direction, and using a digital camera with a
rotating polarization filter to image the light scattered
from the sample. Researchers manipulated the polarization
to minimize light scattered from the rough skin surface,
and positioned the light source in multiple locations to
separate out, and delete, light scattered more than one time
from deeper sample layers. By using certain polarization
settings and combining two images made with the light source
in different positions, they generated a processed image
that reveals significant subsurface structure.
Polarized
light imaging already is used in dermatology to identify
the edges of lesions. The new method minimizes the
effects of two types of unwanted light scattering at once,
and thus, if confirmed by other methods, might someday be
used in a clinical setting to produce more detailed images
of deeper layers of skin.
The
method was developed under a Cooperative Research and Development
Agreement between the two institutions. The project
adapted light scattering techniques originally developed
by NIST researchers to image surface and subsurface features
in inorganic materials such as silicon wafers, mirrors and
paint coatings. Scientists currently are working on making
the new method easier and faster to use.
J.C.
Ramella-Roman, D. Duncan, T.A. Germer. 2005. Out-of-plane
polarimetric imaging of skin: Surface
and subsurface effects. In Photonic Therapeutics and
Diagnostics,
Nikiforos Kollias et al., eds. Proc. SPIE 5686 (forthcoming).
Media
Contact:
Laura
Ost, laura.ost@nist.gov, (301) 975-4034
New
Gas Sensors Patterned with Conducting Polymer
A
n improved method for depositing nanoporous, conducting
polymer films on miniaturized device features has
been demonstrated by researchers at the National
Institute
of Standards
and
Technology (NIST).
Described
in the April 6 issue of the Journal of the American
Chemical Society,* the method may be useful as a
general technique for reproducibly fabricating microdevices
such as sensors
for detecting toxic chemicals.
Unlike
most polymers, conducting polymers have the electrical
and optical properties of metals or semiconductors.
These
materials are of increasing interest in microelectronics
because they are inexpensive, flexible and easy to
synthesize.
Polyaniline
is a particularly promising conducting polymer for
microelectronics
applications, but it is difficult to process because
it doesn't dissolve in most solvents. NIST researchers
have circumvented this problem by dispersing nanoscale
particles of polyaniline into a mild solvent.
"The
beauty of the method,” says NIST guest researcher
Guofeng Li, “is that the polyaniline chain carries
a natural positive charge.” Once the particles
are formed, electrostatic repulsion prevents them from
clumping
together. Moreover, the positively charged particles then
can be manipulated and patterned on complex device structures
by applying an electrical field.
The
process produces a sponge-like coating that efficiently
captures gaseous molecules. So far NIST researchers have
demonstrated that such coatings can detect the difference
between
methanol and water vapor. Additional tests will be needed
before the polymer devices could be used for detecting
toxic gases.
NIST
holds patents for previous work using microheaters coated
with nanostructured tin oxide films. As the microheaters
cycle through a series of temperatures, changes in electrical
resistance are used to detect toxic gases at part per
billion levels. Ultimately, NIST researchers hope to develop
inexpensive arrays of microheater sensors coated with
both polymer and inorganic oxide films optimized to identify
the components of gas mixtures.
*G.
Li, C. Martinez, S. Semancik. Controlled electrophorectic
patterning of polyaniline from a colloidal suspension. Journal
of the American Chemical Society, April
6, 2005.
Media
Contact:
Gail Porter, gail.porter@nist.gov, (301) 975-3392
Quick
Links
NIST
to Host Public Forum on Robot Standards
Urban
search and rescue robots capable of locating victims
at disaster sites are entering the marketplace. To
hasten development and deployment of this life-saving
technology, the National Institute of Standards and
Technology (NIST) and the Department of Homeland
Security
(DHS) will host a public forum on robot standards
from 9 a.m. to 4 p.m., May 13, at NIST’s
Gaithersburg, Md., campus.
The
meeting will explore ideas and timelines for standards
related to urban rescue robot development, testing
and certification. Penrose Albright, DHS Assistant
Secretary for Homeland Security for Plans, Programs,
and Budgets, will provide the keynote address.
Participants
will consider urban search and rescue robotic performance
standards for sensing, mobility, navigation, planning,
integration and operator control. Discussions also
will address ways emergency responders, robot
vendors
and technology developers can collaborate to advance
consensus standards for task specific robot capabilities
and interoperability of components. DHS expects to
use final standards to provide guidance to local,
state and federal homeland security entities for
the purchase, deployment and use of urban search
and rescue
robotic systems.
Attendees
at the May 13 forum are expected to include robot
platform vendors; robot peripherals and software
providers; sensor (chemical, biological, radiological,
nuclear,
explosive) providers; researchers working on robotic
components, platforms and algorithms; government
agencies working on applicable robotic technologies
and sensors; federal, state and local responders
and response agencies; and testing and evaluation
sites and laboratories.
For
further information, visit the conference Web
site at www.isd.mel.nist.gov/US&R_Robot_Standards
or contact Elena Messina at (301) 975-3235 or at
usar.robots@nist.gov.
New
Members Appointed to Policy Advisory Group
Acting
Director Hratch Semerjian, of the National Institute
of Standards and Technology (NIST), has named three
distinguished industry and business experts to
serve
on the Visiting Committee on Advanced Technology
(VCAT), the agency's primary private-sector policy
advisory
group. The new VCAT members—who will serve
three-year terms until Jan. 31, 2008—bring
the body’s
number to 14.
Starting
their service on the VCAT are John F. Cassidy Jr.,
senior vice president, science & technology, United
Technologies Corp. (UTC), Hartford, Conn.; E. David
Spong, vice chairman, ChangeAgent, Inc., Dallas, Texas;
and W. Wyatt Starnes, chairman and chief executive
officer, SignaCert, Inc., Portland, Oregon.
The
VCAT was established by Congress in 1988 to review
and make recommendations on NIST’s policies,
organization, budget and programs. Other VCAT members
are: April M. Schweighart (VCAT chair), retired,
Motorola,
Inc.; Scott C. Donnelly, General Electric Company;
Gary D. Floss, Bluefire Partners, Inc.; Deborah L.
Grubbe, (VCAT vice chair) BP p.l.c.; Lou Ann Heimbrook,
Merck Research Laboratories; Donald B. Keck, retired,
Corning Inc.; Edward J. Noha, CNA Financial Corp.;
Juan M. Sanchez, University of Texas at Austin; Thomas
A. Saponas, retired, Agilent Technologies; James
W.
Serum, SciTek Ventures; and Robert T. Williams, Caterpillar
Inc.
For
more information, see www.nist.gov/director/vcat/.
NIST
Issues HIPAA Security Guideline
A
recent
report issued by the National Institute of Standards and
Technology (NIST) will help federal agencies and others
protect health information. The guide explains the information
security standards adopted under the Health Insurance Portability
and Accountability Act of 1996, which go into effect for
most organizations this month.
The
report summarizes the HIPAA security standards, identifies
key NIST resources relevant to the standards and provides
implementation examples for each. An Introductory
Resource Guide for Implementing the Health Insurance
Portability
and Accountability Act (HIPAA) Security Rule (Special
Publication 800-66) is available at http://csrc.nist.gov/publications/nistpubs/index.html#sp800-66.
NIST
IT Laboratory’s 2004 Technical
Accomplishments
In
the past decade, advances in computing
and communications technologies
have unleashed the power of the
Internet and forever changed the
landscape for commerce and government,”
says Shashi Phoha, director of the
National Institute of Standards
and Technology's (NIST) Information
Technology Laboratory (ITL), in
the foreword to a new publication
highlighting ITL’s technical
accomplishments for 2004. “ITL
has played an important role in
facilitating this transformation,”
says Phoha.
The report describes ITL’s
accomplishments in six technical
programs (security, software, networks,
information access, mathematics
and statistics) and five cross-cutting
areas (biometrics, critical infrastructure
protection, health care, quantum
information and voting systems.)
Paper copies of ITL 2004 Technical
Accomplishments (NISTIR 7169)
are available by contacting Elizabeth
Lennon at elizabeth.lennon@nist.gov.
For a PDF version, see www.itl.nist.gov/lab/pubs2004/FY2004TECHNICALACCOMP.pdf.
NIST
and University of Colorado
Establish Partnership
The
National Institute of Standards
and Technology (NIST) and University
of Colorado (CU) have created a
partnership to enhance scientific,
technical and engineering competence
at the two institutions.
By
signing a Memorandum of Understanding,
NIST Acting Director Hratch Semerjian
and CU President Elizabeth Hoffman
agreed to foster and expand cooperative
research and education efforts
between NIST and CU. NIST Boulder
Laboratories Director Zelda
Chapman
Bailey, NIST Boulder Division
Chiefs, and CU representatives
attended the signing ceremony in
Hoffman’s office.
“Through this agreement,
we will open new doors of research
and move into the future together.
Our goal is to strengthen both
organizations so we can better
promote innovation and address
national needs,” said Semerjian.
For
further information, see www.nist.gov/public_affairs/releases/CU_MOU_04-05.htm.
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to NIST News Page)
Editor:
Gail Porter
Date
created:4/7/05
Date updated:4/11/05
Contact: inquiries@nist.gov
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