Monday, November 11, 2013

CSI: Nuclear

Bruce Pierson has 90 seconds to escape the maze of concrete blocks. He starts at the back of the lab, next to the neutron generator that will start up once the area is clear. Then he weaves through the alcoves, hitting checkpoints that ensure that no one is hidden away working, though they should be alerted by the flashing lights and wailing siren. Anyone trying to come into the area is sensed and admonished by a recording. Once Pierson is out, he locks the door, and the experiment can begin.

Pierson in the maze. The concrete structure on the left contains the neutron source.

In an era of sophisticated terrorist organizations and rogue states attempting to develop nuclear weapons, efforts to prevent nuclear attacks have focused on controlling the materials that could be used for bombs. But if one of these groups did manage a nuclear attack, what information could authorities gain from a careful examination after the blast? Could the remnants left behind reveal anything about the source of the weapons-grade materials?

Pierson, a graduate student in the department of Nuclear Engineering and Radiological Sciences (NERS), is finding out. “In a situation where a nuclear bomb has gone off, you could go to ground zero get a piece of the blast debris from the melt glass underneath the crater. Trapped inside of that glass are the actinides that were used in the weapon,” he explained.

Friday, June 7, 2013

Sensing and software for advanced hybrid car battery systems

They may not know about everything under the hood of Ford’s new Fusion hybrid electric vehicle, but U-M researchers enjoy an up-close look at what’s under the back seat. Ford has supplied one of its most advanced batteries to a team of electrical, mechanical and chemical engineers. In collaboration with Ford and General Electric, (GE) the team is beginning a project that will monitor the thermal and mechanical stresses on battery cells and develop a battery management scheme to reduce those stresses and prolong battery life.

The complete battery pack in its steel case.
The project kicked off with the dissection of the battery pack, giving the team insights into today’s cutting-edge vehicle batteries from the “crash-worthy” steel casing to the cells. “It was a really fun day,” said professor of chemical engineering Charles Monroe.

Thursday, February 28, 2013

Restoring U-M’s most extreme windows

Kevin Mayra wipes down the last pane in the window. Photo: Joseph Xu, Michigan Engineering.

Cleaning three-foot-thick windows, composed of 6-inch-thick panes that weigh up to 740 pounds each, was never going to be an easy task. But by undertaking it, Alex Flick, an engineer in the department of nuclear engineering and radiological sciences (NERS), could get the university’s second hot cell up and running again.

The hot cell will help the Radiation Materials Science group, led by Gary Was, professor of NERS, to gain insights on the aging of components that have spent decades in nuclear power reactors. Most of the reactors in the US are approaching or surpassing 40 years of service, and many are set to operate for another 20 years. With no new reactor construction since 1977, US reliance on fossil fuels will have to rise steeply if these reactors shut down before new ones can take their places. To keep them running safely and efficiently, nuclear engineers need be smart about making repairs – and that means figuring out what components will break and when.

Friday, October 5, 2012

Fluid cathedrals: Gels under the microscope

Professor Michael Solomon and doctoral student Lilian Hsiao, both in chemical engineering, discuss the architectural structures revealed by the 3D map of particles inside a gel. Image credit: Laura Rudich.

A dollop of hair gel might not look like much, but Michigan Engineering researchers have found that it's a labyrinth of chambers and domes, constructed by the particles inside. These structures allow the gel to hold its shape and determine how much pressure it can withstand before it starts to flow.

While manufacturers currently use trial and error to develop gels with a particular degree of solidity, this discovery could provide a way to design gels for particular applications.

Friday, August 10, 2012

Could flowing liquid batteries be key to a renewable grid?

Aaron Shinkle, a graduate student in the group of professor Charles Monroe, prepares a liquid battery test cell. Photos by Joseph Xu, College of Engineering Communications.

So-called flow batteries could be the answer to storing solar, wind, and other renewable energy on the scale that power companies need, but it will take engineers and scientists to get them to that level.

“People say they’re putting a solar panel on their house,” said Charles Monroe, professor of chemical engineering. “They don’t say they’re putting a gigantic battery in their attic.”

But if homeowners want to get the most out of those solar panels, they had better install a means to store the energy they harvest. And that’s just the small version of the problem – as renewable energy sources integrate with the grid on a large scale, batteries fit for power stations are a crucial piece of the puzzle.

With current lithium-ion technology, batteries the size of semi-truck trailers can hold 500 kilowatt hours (kWh) – or enough to power about fifteen US houses for a day. Unfortunately, they degrade somewhat with each recharge and survive for only about a thousand recharges. In order to develop batteries that can hold as much energy as lithium-ion designs and also last for many years, Monroe’s team has joined forces with that of Levi Thompson, a fellow professor of chemical engineering.

Wednesday, June 20, 2012

Bolt from the blue in the plasma lab

A mod on the underwater plasma jet experiment turned up some unexpected chemistry.

Photo by James Rotz, Michigan Engineering
It grew invisibly in the darkened laboratory, lit only by the thimbleful of plasma that glowed purple in a beaker of water. Nuclear Engineering and Radiological Sciences (NERS) graduate student Ben Yee had turned out the lights, shaded the windows, turned off the computer monitors so that the detector would only pick up the light from the plasma. After half an hour of taking data, he turned off the plasma and turned on the lights to find that a mysterious blue jelly had taken up residence in the bottom of the beaker.

It sounds like an alternate beginning for the 1950s horror flick The Blob, but Yee isn’t worried. “I haven’t heard of any unusual deaths or missing persons in the past few days,” he said. Lifting a beaker from another trial of the experiment, he studied the algae-like green jelly at the bottom. “It seems peaceful. Family-friendly,” he added. So, Flubber’s lazy cousin?

Tuesday, June 19, 2012

Senior citizens behind the wheel

Older drivers get hurt worse in crashes. A Michigan Engineering professor thinks their posture and body shape may play a role. We visit the U-Mich crash lab to learn more about the study. E9XPTV3FVPB7

Crash test dummy
A mid-sized male crash test dummy prepares for a test in the
University of Michigan Transportation Research Institute's sled lab.
Photo by Laura Rudich

There’s something curiously morbid about crash test dummies. They have an unnerving combination of lifeless and life-like features.

They even wear shoes in the sled lab at the University of Michigan Transportation Research Institute—brown oxfords for the mid-sized male model on deck for a head-on collision at 30-mph.

“We want the tests to be as realistic as possible,” explains Matt Reed, research associate professor at UMTRI and in industrial and operations engineering.

But there’s only so much Reed and his colleagues in the field can do right now. The federal government tests crash protection for adults with just two dummy sizes, an average man and a small woman. Many people don’t fall into one of these categories. So Reed is working to get a more accurate picture of American drivers and passengers.

Right now, he’s studying older drivers. He has found that they tend to fare worse than younger people in crashes of the same severity. A lot of factors are likely to blame, Reed acknowledges, but he’s zooming in on a couple that might be easier to affect—seatbelt fit and driver posture. His team is also measuring body shape with a special 3D scanner. Reed says there’s never been a systematic study like this. All summer he and his team, which includes eight engineering undergrads, are measuring people.