Tech Briefs Magazine - August 2021 - 35

water, there could be a minuscule chance
that these viruses make it into drinking
water supplies.
At treatment facilities, raw water generally
undergoes a three-step purification
process: coagulation, filtration, and
disinfection. In the coagulation step, certain
metallic salts are added to initiate
particles suspended in water to join
together into millimeter-sized clumps.
These clumps then settle down as sediment
and are easily separated from the
water. The researchers tested to see if
enveloped viruses also assembled into
bundles during coagulation.
For their experiments, they added a surrogate
of the coronavirus that specifically
infects bacteria to clean water. Next, they
separately tested the action of a coagulant
commonly used in water treatment plants.
After coagulation, they studied small samples
of the virus-infused water under an
electron microscope and found that the
virus strain assembled on the coagulants,
forming clusters. They then checked the
presence of infectious viruses in the water
after removing the clumps and found
there was a 100,000 reduction.
The researchers noted that although
they used the coronavirus surrogate for
their study, the results are readily generalizable
to other viruses that have similar
surface characteristics - notably, a lipid
bilayer envelope and similar spike proteins.
In the real world, wastewater contains
a slew of viruses, unlike the team's
experiments that included just a single
strain of virus. In their next set of experiments,
they plan to investigate if coagulation
is still as effective at decontamination
in these scenarios.
The work suggests that surface water
treatment plants might already be well
equipped to meet virus regulations for
drinking water and coagulation is just the
first step in the water purification pipeline.
Additional purification steps will only
attenuate enveloped viruses further, alleviating
associated health risks even more.
For more information, contact Amy Hal bert
at ahalbert@tamu.edu; 979-458-4243.
Tension Element Damping (TED) with Hydraulics for
Large Displacements
Applications include wind turbines, solar arrays, commercial space mobile launchers, and
industrial process stacks and equipment.
Marshall Space Flight Center, Alabama
ASA engineers developed a new ap -
proach to mitigating unwanted structural
vibrations that cause maintenance
issues and compromise the performance
and safety of large, tall structures. The
Rotational Tension Element Damper
(RTED) uses a controlled tension line,
backed by hydraulics, to damp large displacements
in large structures.
NASA's method is fundamentally different
from conventional passive and active
N
vibration damping methods used today.
The RTED uses disruptive modal coupling
between two different structures,
each with their own vibrational behavior,
to provide vibration damping for one or
both of the structures. This novel reactive
vibration damping meth od uses feedback
from the vibrational displacement itself,
such as the tension and compression
cycles from the movement of the vibrating
structure (like a wind turbine or tower),
to disrupt the vibration. Line tension is
provided by either hydraulic, pneumatic,
or magnetic means to suit the application
and the size/displacement of the vibration.
Com pared to conventional spring
dampers, TED devices are simple in de -
sign, lightweight, very effective, and have
a smaller footprint.
NASA built RTED prototypes that were
successfully tested on a 170-foot-long
wind turbine blade in test beds. In this
case, the RTED device damped the vibration
of the large, tall turbine blades relative
to a stationary anchor structure on
the ground using a line and spring coupled
to both the blade and the anchor
and controlled by a spool fitted with a
one-way clutch.
When force is applied from heavy wind,
for example, the resulting movement of
the tall structure triggers the necessary
tension and compression cycles in the system
to engage the rotating damper. The
reaction force interferes with the rotation
speed of the spool and disrupts and damps
the vibration in the tall structure.
NASA is actively seeking licensees to comThe
RTED device can dampen the vibration of large, tall turbine blades. When force is applied from
heavy wind, the resulting movement of the tall structure triggers the necessary tension and compression
cycles in the system to engage the rotating damper.
Tech Briefs, August 2021
Cov
www.techbriefs.com
ToC
mercialize this technology. Please contact
NASA's Licensing Concierge at AgencyPatent-Licensing@mail.nasa.gov
or call us
at 202-358-7432 to initiate licensing discussions.
Follow this link for more informa -
tion: https://technology.nasa.gov/patent/
MFS-TOPS-109.
35

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Tech Briefs Magazine - August 2021

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