Archive for April, 2009

A brighter future

April 29th, 2009 by Gene
 
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Photo: Jesper Noer/stock.xchng

How many engineers does it take to make a better light bulb? We’ll find out, today on Engineering Works.

The round incandescent light bulb we all know hasn’t changed much since Thomas Edison invented it 125 years ago. Thin wires, called filaments, inside the glass bulb glow when electricity zips through them. That glow gives us light to see by. But there’s a hitch. Only about a tenth of that energy gives us light. The rest just heats the bulb so we can burn our fingers. Ouch!

Fluorescent lights – those long tubes that light offices and other commercial spaces – appeared in 1938. Instead of filaments, fluorescent tubes are filled with a gas that glows when electricity passes through it. They’re lots more efficient.

Fluorescent lights are cool. Really. They don’t get hot, and they need just one-fourth the energy incandescent bulbs need to produce the same amount of light. And fluorescent bulbs last 10 times longer than incandescent ones. They had problems, though. They didn’t fit a lot of places regular light bulbs did. And they hummed.

Then, compact fluorescent lamps entered the picture in the 1980s. They solved a lot of the problems regular fluorescents had: they screw into regular light sockets; they’re small enough to fit most places a conventional bulb will fit; they don’t hum; and they’re as stingy with the energy they use as regular fluorescent bulbs.

Guess it’s time to turn out the lights for today.

EngineeringWorks! 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. Engineeringworks.tamu.edu.

Autonomous lawnmower

April 22nd, 2009 by Gene
 
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Photo: Husqvarna

Be honest. Nobody likes to cut the grass. But what if your lawnmower did the lawn by itself? We’ll take a look. Today, on Engineering Works!

Everybody likes their lawn to be green and neat. But if your lawn is a big one, you can spend hours keeping the grass trimmed to the height you like. Not fun.

Engineers don’t like to spend time following a lawnmower around the yard any more than we do. So they figured out a way not to.

Enter the robot lawnmower. We’re not kidding — a lawnmower that starts up by itself, mows the lawn and goes back to where it lives. All by itself, once you’ve set it up. It’s not especially complicated — no electronic maps of your yard, no GPS receivers. Just a grass-level antenna and a receiver that keeps track of where the mower is in relation to that antenna. And the ability to follow a pattern it’s cut before.

Robot lawnmowers are electric, so they’re quiet. And since you’re not watching where the mower is going, you could program one to mow your yard while you sleep, if you wanted to.

They’re not cheap. Robot mowers run about $1,500 each. But some people are willing to pay a lot for the extra time they’ll gain from not having to mow their lawns each weekend.

Our lawn is getting shaggy and the only robot pushing our mower is us. 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. Engineeringworks.tamu.edu.

Extreme fabrics

April 15th, 2009 by Gene
 
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Photo: G&A Scholiers/stock.xchng

Everybody knows about cloth. Fabric. It’s that stuff your jeans are made of. Engineers are turning fabric into stuff Levi Strauss never dreamed of. We’ll do more than dream. Today. On Engineering Works!

Cloth. Fabric. Textiles. Whatever you call it, it’s been around a long time. As long as civilization, probably. Mostly it’s been used for clothes. It’s also carpets. Furniture upholstery. Sails for boats. Now, engineers are weaving threads into stuff you’d never imagine.

How about a knitted bag that helps a failing heart pump blood? A jacket that conducts electricity through its threads and keeps you warm. Or valves in automobile engines, braided from carbon fibers.

Using cloth in unusual ways is nothing new. Roman engineers used burlap to help stabilize their famous roads. Automobile tires use fabrics to make them strong and durable. That hasn’t always worked quite the way the engineers planned.

Nylon fabric in tires in the 1960s used to flatten out if they stood still for a while. Then the flat spot in the tire thumped until it warmed up again. Oh, well. The reinforcing fabric in today’s tires don’t bump. They also get 80,000 miles before they wear out.

New fabrics pretty much define high-tech. A German company has invented an outdoor jacket that plays MP3s. NASA is developing a spacesuit fabric that acts like a mousepad to control computers.

The fabric of this week’s show is just about worn out. We’ll 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. Engineeringworks.tamu.edu.

Plastic and steel

April 8th, 2009 by Gene
 

Image: Library of Congress

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That’s the sound of iron turning into steel. With some help from your plastic water bottle. We’ll explain. Today, on Engineering Works!

Steel makes possible a lot of things we take for granted. Cars. Girders for big buildings. Knives that keep a sharp edge. Useful stuff, steel.

To make steel from iron, you mix the iron with processed coal – known as coke – and heat it. Really hot. That gets rid of impurities that make iron weaker and less durable than steel. Making steel uses a lot of coal, and materials engineers are looking for ways to replace some of it. Maybe as much as half – with plastic. Like your old water bottle.

Sounds goofy, huh? Not really. Plastic doesn’t look much like coal, but inside it’s almost the same. Hydrogen. Oxygen. And carbon. It’s the carbon that counts. Carbon – from coal or plastic – snags the oxygen in iron ore and takes it away. What’s left is steel. The problem is that the oxygen – in the form of carbon dioxide and carbon monoxide – ends up in the air. Raw materials for smog and acid rain. Plus other bad stuff, like mercury.

Replacing coal with plastic sidesteps most of this. You still get some carbon dioxide when you replace coal with plastic, but it’s a lot less. And you get rid of a lot of plastic in the process, too.

We’re through processing our show for today. 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. Engineeringworks.tamu.edu.

Space junk

April 1st, 2009 by Gene
 

Image: European Space Agency (ESA)

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We’re going to talk trash like you’ve never seen — space junk. Today, on Engineering Works!

The next time you go outdoors, stop a minute and look straight up in the air. You can’t see it from here, but there’s a whole junkyard floating up above your head. It’s the stuff we’ve left behind from almost 50 years of space exploration.

Think about it. There’s so much junk in orbit up there that nobody knows for sure how much there really is. At least 100,000 pieces of stuff, maybe millions. More than 7,000 of them the size of a baseball or bigger. Some as small as chips of paint. In fact, a lot of it is chips of paint, from rockets and satellites. A few – broken down or worn-out satellites – are as big as washing machines.

Don’t snicker at those orbiting paint chips, either. They don’t sound like much, but they’re moving at more than 17,000 miles an hour. Anything moving that fast can do real damage if it hits something. One chip hit a window on the space shuttle. It gouged a crater as big as your thumbnail. Imagine what one of those dead satellites could do.

Engineers are designing shields to protect against collisions with orbiting junk. It’s a tough assignment – shields have to be strong enough to stop the junk before it hits anything important and light enough to lift into orbit.

Time to take out our trash. See you later.

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. Engineeringworks.tamu.edu.