in New Orleans
• Westerink Briefs Congress on Advances in Storm Surge Predictions
• New Class of Materials Discovered
• Feasibility of Permanent Moon Base Questioned
• Project Confirms Skyscraper Design
in New Orleans
Most of the stories coming from the Gulf Coast in the aftermath
of the 2005 hurricane season have centered around human and economic
tragedy, which is as it should be. People lost their lives, their
homes, and their livelihoods. An entire city may have lost its identity.
But there are also stories that lie beneath the surface, like the
mold that’s proliferating in New Orleans.
An October 2005 report
issued by the Mold Work Group of the Center for Disease Control and
Prevention stated, “The duration and
extent of flooding and the number of structures flooded as a result
of Hurricanes Katrina and Rita make the likelihood of massive mold
contamination in buildings a certainty.” This wasn’t
news to Jennifer R. Woertz, assistant professor of civil engineering
and geological sciences. She had already submitted a proposal and
been awarded a grant from the Small Grants for Exploratory Research
program of the National Science Foundation in September 2005.
time Woertz, in collaboration with Wilasa
Vichit-Vadakan, the Clare
Boothe Luce Assistant Professor of Civil Engineering and Geological
Sciences, and Dustin Poppendieck, assistant professor of environmental
resources engineering at Humboldt State University in Arcata, Calif.,
were finalizing plans to study eight homes in the Orleans Parish
over a three-month period in order to determine the type and extent
of mold growing in the homes, as well as establish a guide for safe
reconstruction efforts in the area.
In addition to monitoring the
moisture content of the materials in the homes, the team monitored
the levels of mold in the ambient air. “Mold
is hydrophobic,” says Woertz. “It’s very difficult
for spores, which are two to five microns in diameter, to infest
a material when the material is saturated. So we didn’t expect
to record a lot of mold until the drying out process began.”
spores the team found, mostly penicillium and aspergillus, are two
types of molds that can cause respiratory problems, triggering allergies
or exacerbating asthma. They can also cause skin infections in people
with weaker immune systems. “We’re expecting
to see a variety of health problems arise in the months to come — affecting
the evacuees returning to live as well as workers attempting reconstruction,” says
Woertz. “Proper respirators will be vital for construction
workers. But it is especially important that people whose immune
systems are compromised, such as the elderly or small children, not
return to contaminated homes.”
Woertz’s concern is that
unlike asbestos and lead, which are controlled by strict Environmental
Protection Agency guidelines, no clear cut ties exist between increased
respiratory problems, such as asthma, and mold contamination. For
this reason, there are no standards or threshold limits as to the
amount of mold that is acceptable in a home. There are also no governmental
certifications given to companies who claim they remove mold.
concern that the study addressed is the structural integrity of the
buildings. Although it does not grow quickly, mold eats whatever
it is growing on to survive. It is also very difficult to remove.
Because it is everywhere, it is impossible to completely remove.
Contractors in New Orleans will need to work under negative pressure,
venting the air, and the airborne spores released by the demolition
process, outside. The next step should involve a HEPA vacuum or filtration
process, to make sure as many of the spores have been removed as
possible. According to Vichit-Vadakan, should the mold attached to
surfaces not be removed, it could cause dry rot and destroy the structural
integrity of a building.
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Westerink Briefs Congress on Advances in Storm Surge Predictions
In November 2005 as part of an American Mathematical Society report
to the U.S. House Committee on Science, Joannes
J. Westerink, associate
professor of civil engineering and geological sciences, and Clint
Dawson, professor of aerospace engineering and engineering mechanics
at the University of Texas, presented “From Katrina Forward:
How Mathematical Modeling Predicts Storm Surge.” During the
presentation, they described the research that has been conducted
over the last decade and how it has increased the accuracy of predictions
regarding the extent and magnitude of flooding as a storm progresses.
research focuses on mathematical modeling and computer simulation as
tools in forecasting storm surges due to hurricanes and tsunamis. He
developed the Advanced Circulation Model (ADCIRC), an authoritative
computer model for storm surge prediction, with Massachusetts Institute
of Technology classmate Richard A. Luettich
Jr., professor of environmental
sciences and engineering and director of the Coastal Circulation and
Transport Laboratory at the University of North Carolina at Chapel
Hill. Westerink is also co-leader of the surge and waves team of an
Army task force that is evaluating hurricane safety policies for New
Orleans and southeastern Louisiana.
ADCIRC, used by Westerink and his
team, is also used by the U.S. Army Corps of Engineers, the Federal
Emergency Management Agency, researchers at Louisiana State University,
and the state of Louisiana to help predict water levels during storms
and design levees.
The report to Congress should prove useful as local,
state, and federal officials continue to plan for what is predicted
to be an active 2006 hurricane season. The Atlantic Basin season, responsible
for many of the storms hitting the U.S., runs from June 1 through November
30. Forecasters anticipate 17 named storms, nine of which will be hurricanes.
Five of those will be major hurricanes. According to the Saffir-Simpson
Hurricane Scale, which uses wind speed, estimated property damage,
and potential flooding possibilities as markers, a major hurricane
is one in which the wind reaches or exceeds speeds of 111 m.p.h. Between
1950 and 2000, there have been an average of two major hurricanes a
year. Three major hurricanes were predicted for 2005, but seven occurred.
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New Class of Materials Discovered
“No one has seen anything like these materials,” says
Peter C. Burns, the Henry J. Massman Jr. Chair of the Department of
Civil Engineering and Geological Sciences. He’s speaking of the
actinyl peroxide compounds that he and Lynda
Soderholm, a chemist at
Argonne National Laboratory, discovered. These nano-sized compounds,
which represent a new class of materials, are believed to be important
in environmental systems because of the way they could impact the transport
of heavy metals and radionuclides in geologic fluids.
Burns and Soderholm
believe that these nanospheres most likely form in alkaline mixtures
of nuclear waste, such as in nuclear waste tanks. They encountered
the materials during studies conducted in conjunction with the Environmental
Molecular Science Institute at Notre Dame. As the research continued,
the project was moved to Argonne because its facilities enabled safe
interaction with neptunium. Argonne’s Advanced Photon Source
was also used during the studies.
Formed from uranium and neptunium
peroxide solutions, actinyl peroxide compounds self-assemble into nano-sized
shells that may prove useful in a variety of applications. For example,
if these nanostructures could be harnessed and manufactured, industry
could use them as catalysts, computer chips, solar cells, flexible
batteries, or data storage devices.
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Feasibility of Permanent Moon
Clive R. Neal, associate professor
of civil engineering and geological sciences, is one of a 15-member
team of planetary geologists examining moonquakes and the effect they
may have on a future permanent moon base. Using data from seismometers
placed at lunar landing sites between 1969 and 1972 and collected through
1977, the team discovered four different types of moonquakes, which
could impact any structure constructed on the surface of the moon.
The types of quakes identified
from the more than 12,000 events recorded, include quakes
generated by meteorite strikes; deep moonquakes, which occur approximately 700
kilometers below the surface; thermal moonquakes, which occur close
to the surface as a result of temperature fluctuations at dawn when
the sun hits the surface of the moon; and shallow
occur only 20 to 30 kilometers below the surface.
as “shallow,” these types of quakes are
the most powerful and long-lasting. According to Neal, a few of the shallow
quakes measured up to 5.5 on the Richter scale. “Most earthquakes
last a minute or two,” says Neal. “Shallow moonquakes can
last up to 10 minutes.” Because the seismometers were placed in
a relatively small region of the moon, the data is inconclusive, but
it does suggest that additional analysis is needed before constructing
a permanent lunar base.
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Project Confirms Skyscraper Design
initial results of the Chicago Full-scale Monitoring Project as reported
in the November 2005 issue of Engineering News
Record show that U.S.
design assumptions are generally valid in predicting building sway.
The three skyscrapers featured in the study have been performing
as previously predicted, although they have not yet faced a severe
Ahsan Kareem, the Robert Moran Professor of Civil Engineering
and Geological Sciences and director of the Natural Hazards Laboratory
(NatHaz), led the study in collaboration with Tracy
Kijewski-Correa, the Rooney Family Assistant Professor of Civil Engineering and Geological
Sciences. They worked in conjunction with Skidmore, Owings & Merrill
(SOM), a leading architecture firm, and Canada’s Boundary Layer
Wind Tunnel Laboratory. The team was funded by the National Science
Foundation and is currently seeking more funding to expand the study.
project involved fitting three Chicago buildings with accelerometers,
which were able to detect each skyscraper’s motion along perpendicular
axes, as well as any twisting movement. Data from the instruments were
transmitted to a communication hub in Chicago’s SOM building
and then relayed to Notre Dame. Results indicated that the buildings
have been responding in accordance with their design, even though they
were built when scale-model testing and computer modeling techniques
were not as advanced as they are today.
NatHaz, which coordinated the
study at the University of Notre Dame, was created in 2000 to quantify
the load effects caused by natural hazards on structures, such as winds,
waves, and earthquakes. Researchers in the lab also seek to develop
innovative strategies to mitigate and manage the effects of these hazards.
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