Archive for September, 2009

Leveraging engineering

September 29th, 2009 by Gene
 

Image: Wikipedia

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Most of the time when we think about engineers, we think about the nifty things they’re designing and building, now. But a lot of what they do now started a long time ago. We’ll take a look back, today on Engineering Works!

The engineers we know design and build new fuel-efficient cars, ultra-fast computers, tall buildings. Cool stuff. But many of the principles they use are thousands of years old. Consider the lever. You know what a lever is. It’s a bar of something that pivots over something else. It’s a powerful idea. Every geometry student knows what the ancient Greek mathematician Archimedes said about levers: give me a fulcrum and a place to stand and I’ll move the world.

If we think about levers at all, we probably picture playground teeter-totters or prybars. But these are only the beginning. Hammers, the oars in a rowboat, wedges used to split wood. They all use the principles of the lever. Then there’s the wheel and the pulley. And the screw. They’re levers, too.

Archimedes gets a lot of credit for understanding the lever. But he wasn’t the first to think about how levers work. The earliest recorded discussion of levers appeared at least a generation before Archimedes and his famous statement. So the next time you see something really neat that an engineer did, take a minute to wonder a little. It all started a long time ago.

Long time or short, we’re done. See you next time.

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. http://engineeringworks.tamu.edu.

The numbers of power

September 22nd, 2009 by Gene
 

Photo: Thomas Hawk/Flickr.com

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We’re going to listen to some big words. Engineers know what they are. Today, on Engineering Works!

Engineers use numbers all the time. Sometimes these numbers are really big. Consider power engineers. Power engineers design and build the systems that make and deliver the electricity that lights our homes. They routinely talk in terms that include millions and sometimes billions. Over time, scientists and engineers have invented some nifty words to describe big numbers.

Here’s an example. Your utility company charges you for the number of kilowatt-hours of electricity you use. A kilowatt-hour is a thousand watts of electricity used for one hour. A kilowatt will light a 100-watt bulb for 10 hours.

In the world of big number words, kilo, or a thousand, is pretty puny. A kilogram only weighs a little more than two pounds. Utility company generators regularly produce power measured in millions of watts – megawatts. Many nuclear-powered generators have outputs of more than 200 megawatts. Even this is pretty small when you talk about electric power consumption around the world. That stands at just under two terawatts, two trillion watts. Makes your electric bill seem pretty trivial.

Even this isn’t the end of it. An experimental laser getting ready to go into operation will produce pulses that measure more than one petawatt. Now we’ve got a really big number. A million trillion. And there are words to talk about numbers even bigger than this. But not today.

Our number is up, and we’re quitting. See you next time.

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. http://engineeringworks.tamu.edu.

Plastics primer

September 15th, 2009 by Gene
 

Photo: geoftheref/Flickr.com

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If you look around, there’s plastic everywhere. We’ll look, too. Today, on Engineering Works.

You see a lot of plastic because it works. It’s lighter and cheaper than metal and it’s more durable than cardboard. A lot of it can even be recycled.

In fact, engineers have designed some plastics especially to be recycled or to break down safely, quickly, completely. Biodegradable. This is the easy part. Now it gets complicated. Different biodegradable plastics need different treatments to break down as they’re supposed to.

For instance, hydrobiodegradable plastics. They’re made from food or plant starch, sometimes with oil-based polymers. Micro-organisms break them down into water, carbon dioxide, methane and biomass. This is good, but it needs an industrial composter to work. Most folks don’t have one.

Oxobiodegradable plastics are made from petroleum byproducts, like traditional plastics. Most of them have a built-in self-destruct, and they start to break down after a preset period of time. Much more quickly than traditional plastics. Sunlight, heat and what engineers call mechanical stress – basically, stomping on it or cutting it up – do the trick.

Here’s the point: getting plastics to decompose isn’t as simple as it sounds. For instance, some plastics that break down easily in the open air last forever in sealed landfills. If you recycle plastic – and we hope you do – check out what each kind of plastic you have needs to break down.

Our time today is about broken down. See you next time.

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.

Pouring the pyramids

September 9th, 2009 by Gene
 

Photo: Bruno Girin/Flickr.com

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Everybody knows the Egyptians used huge stone blocks to build their pyramids. Some engineers aren’t so sure. We’ll listen to the argument. Today, on Engineering Works!

Everybody learned in school that ancient Egyptian engineers used thousands of huge limestone blocks to build the pyramids. What we didn’t learn was how the Egyptians got those blocks from the ground to the top of those pyramids.

Archaeologists and engineers have speculated for decades about how they did it. Sloping ramps. Rollers. Gangs of sweating slaves. You’ve seen the movies. But nobody knows for sure.
Now, materials engineers have come up with a new explanation that has the archaeologists in an uproar. Maybe some of those huge limestone blocks weren’t really limestone. And maybe those gangs of slaves didn’t push them up the ramps after all.

The engineers think just maybe the Egyptians invented an early kind of concrete from crushed limestone and binders that work just like the Portland cement in modern concrete. Since the powdered limestone would be just like the limestone in limestone blocks, it would be really hard to tell the difference.

So maybe instead of thousands of slaves pushing huge blocks of stone around, they were carrying bags of wet concrete and pouring it into forms on top of the half-built pyramids. Not as mysterious and romantic as big blocks of stone, but it could have worked.

We haven’t been pushing stone or carrying concrete, but we’re still done. See you next time.

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.

Stop, look and … listen

September 1st, 2009 by Gene
 

Photo: Francois Lariviere/iStock

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Photo: Darrel Ronald/Flickr.com

Here’s a question you probably never thought to ask: what should your car sound like? We’ll listen for an answer, today on Engineering Works!

We’ve all listened to cars, all our lives and we’ve always heard them. The clatter of an old VW bug. The rumble of a high-performance muscle car. But those sounds may be fading into the past. As hybrids and all-electric cars become more common, the sound of cars is changing. Hybrids and electric cars make almost no noise at all, especially when they’re moving slowly.

Some engineers think this could be a bad thing. Think about it. You’re walking across a parking lot, minding your own business, and suddenly there’s that almost-silent electric car. Right on top of you. You never heard it coming. And imagine what it would be like at night. Or any time if you can’t see.

Engineers are working on ways to fix the problem. By adding sound back into electric cars. Some are going the simple route. Just plain noise. One possible added sound is a little like a jet engine with some added static. Kind of hard to miss.

Another possibility some engineers are exploring would allow you to change the sound of your electric car or hybrid to fit your mood. Anything from that jet to a superstock Dodge or an 18-wheeler.

Our car isn’t electric or silent. It’s just plain noisy. 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.