Archive for December, 2009

Future moon base

Photo: NASA

Moon power

December 29th, 2009 by Gene
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When astronauts move in with the man in the moon in a few years, they’re going to need power. Nuclear energy on the moon. We’ll check it out. Today, on Engineering Works!

When the Apollo astronauts were on the moon, they only stayed a few days at a time, and batteries or fuel cells did them just fine. But now NASA is talking about astronauts staying for weeks or months. Batteries just won’t do it. They’re going to need a long-term source of power for their exploration and scientific activities.

Space experts are proposing all sorts of power sources, from solar panels to king-sized fuel cells. One of most popular ideas is a small nuclear reactor.

NASA engineers are working on an ultra-compact nuclear power plant that should generate enough electricity to run an average American house. Or a lunar exploration base. And do it for eight years. Or longer. The reactor itself is about the size of a big wastebasket. The whole thing would fit into an 18-wheel trailer with room to spare and would weigh about the same as an armored humvee.

Not everybody is convinced sending a nuclear reactor to the moon is a good idea. Protestors objected to launching NASA’s 19-97 Cassini probe, which carried 72-pounds of plutonium fuel. But the NASA engineers are convinced the lunar reactor is safe.

Our reactor is still powered up, but it’s time to go. See you next time.

Engineering Works! is made possible by Texas A&M Engineering and produced by KAMU-FM in College Station. Learn more about engineering. Visit us on the World Wide Web.  http://engineeringworks.tamu.edu

Streetlights at night

Photo: HarshWCAM3/Flickr.com

Turning down the lights

December 22nd, 2009 by Gene
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Paris may be the city of lights, but engineers in France are trying a new way to reduce municipal electric bills. Streetlights. Today, on Engineering Works!

It’s not Paris, but people in the French city of Toulouse still like to have their streets lit at night. There’s a problem, though. The city’s electric bills are high and climbing. So they’re trying a new way pedestrians who walk the city’s streets after dark can help. It’s easy. Just keep walking.

What they’re doing is to install sensors in the lampposts that hold up the streetlights. When the sensors detect the body heat of an approaching pedestrian, the light clicks from dim to bright. When the pedestrian moves on – between 500 and 600 yards away – the streetlight dims its light again.

They’re testing the sensor-operated streetlights now, and if it works on a short stretch of mostly residential street, they’re going to start by installing the sensors along a stretch of busy street between the city’s sports stadium and the university campus. If it works there, they plan to take it citywide. They expect to cut electricity consumption by streetlights on busy streets in half.

City administrators across France are watching what happens, and others around the world are watching, too. A group of city council members from Osaka, Japan, visited a while ago to see firsthand how it’s done.

Our streetlights are still shining, so we’ll leave before somebody dims them. See you next time.

Engineering Works! is made possible by Texas A&M Engineering and produced by KAMU-FM in College Station. Learn more about engineering. Visit us on the World Wide Web. http://engineeringworks.tamu.edu.

Virtual Tech Recovery

Photo: Elizabeth Lockwood/health.mil

High-tech rehabilitation

December 15th, 2009 by Gene
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Soldiers and Marines fighting in Iraq and Afghanistan are in the news almost every day. Some are wounded. Badly. We’ll look at how engineers are helping them put their lives back together. Today, on Engineering Works!

It’s one of the goofy things about modern war. Personal armor, air evacuation and better field medicine mean that many wounded who would have died in previous conflicts, live. But they live with the effects of severe burns, brain injuries, blindness, spinal damage, amputations. Since 2001, almost 700 have lost at least one limb.

This is where technology lends a hand. Meet CAREN, the computer-assisted rehabilitation environment. CAREN is a dome that helps soldiers with artificial legs or arms learn to use them in different situations. Walking down a busy street? See other pedestrians around you. See the buildings. Hear and see traffic. A walk in the woods? See the trees, hear the wind and the birds, feel the trail twist and turn under your feet.

Computers linked to sensors on the body move a treadmill to match the ground you’d be walking over and adjust video images all around to what you’d see as you walk. There’s more to CAREN than helping injured troopers learn how to deal with their wounds. Medical researchers also use the simulator to study problems like balance disorders and how stress affects people with post-traumatic stress disorder.

There’s no clever way to end this one. Hang in there, guys. See you next time.

Engineering Works! is made possible by Texas A&M Engineering and produced by KAMU-FM in College Station. Learn more about engineering. Visit us on the World Wide Web. http://engineeringworks.tamu.edu.

Nuclear Power Plant

Image: bigod/Flickr.com

The next nukes

December 8th, 2009 by Gene
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Nuclear energy has been in the doghouse for decades. But now it’s getting another look from policy-makers. We’ll look, too. Today, on Engineering Works!

People in the United States have always been a little skittish about nuclear energy. Accidents at Three Mile Island and Chernobyl in Ukraine didn’t help. Construction on the most recent nuclear power plant was started in 1977, and it didn’t go online until 1996.

Then came climate change, and environmental policy-makers took another look at nuclear energy. Unlike coal-fired power plants, nuclear plants produce no carbon dioxide and – get this – even less radiation than coal-fired power plants.

Engineers are working on designs for new reactors that they say should be simpler and safer than existing reactors, and should even deal with nuclear waste. The spent fuel should be a two-fer, the engineers say. Recycle it into new fuel that could go back into the reactor. This reduces the amount of waste we have to store. The technology to do this already exists, and what we now call spent fuel still has about 95 percent of its energy.

New reactors should be safer, with fewer ways operators could accidentally cause something to go wrong. And more automatic safeguards against accidents, like cooling systems that rely less on pumps and more on gravity to keep coolant where it needs to be for safe operation.

Our power plant is humming along, and we’re done. See you next time.

Engineering Works! is made possible by Texas A&M Engineering and produced by KAMU-FM in College Station. Learn more about engineering. Visit us on the World Wide Web. http://engineeringworks.tamu.edu

Clocks

Image: fdecomite/Flickr.com

Between the ticks

December 1st, 2009 by Gene
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We’re going to do this one on time. Come along with us as we figure out how. Atomic clocks, today on Engineering Works!

Time never stops. We’ve been keeping track of it for a long time, and we’ve done it a lot of different ways – sundials, dripping water, candles with marks on them, springs and gears and pendulums, quartz crystals and electricity.

All of these timekeepers have one thing in common. They keep track of the interval between one tick and the next. And they all have a problem — the same problem. The intervals they measure aren’t always the same. They’re probably not that different, but they vary – a little or a lot. If you need to measure time exactly – to navigate a space probe or use a global positioning system – they’re not good enough.

This is where special clocks called atomic clocks come in. Instead of pendulums and gears or even quartz crystals, atomic clocks use the vibration between the nucleus and electrons of atoms – usually cesium atoms – to set the interval we use to measure time passing. Even this interval varies a little. But not much. The atomic clock at the Naval Observatory near Washington, D.C., is accurate to within about one second in 20 million years.

If you think this is accurate, clocks based on hydrogen atoms do even better over the short term. But over longer periods of time, cesium is better.

Time’s up. We’ve got to go now.

EngineeringWorks! is made possible by Texas A&M Engineering and produced by KAMU FM in College Station. EngineeringWorks! is on the World Wide Web, too. Visit our web site. http://engineeringworks.tamu.edu