Archive for August, 2008

Natural Design

August 26th, 2008 by Gene
 
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Engineers are finding design inspiration in new places. We’ll find some, too. Today on Engineering Works!

When most of us think of engineering design, we picture computers and high-tech laboratories. A lot of engineers do, too. But some are finding inspiration in odd places. Like the Australian outback. A spiky inch-tall lizard called the thorny devil that lives in the dry, 100-degree-plus desert is giving engineers ideas for efficient ways to move traces of water from one place to another.

This lizard doesn’t even have to open its mouth to get a drink. All it has to do is step into water and the water wicks up its legs and disappears. Researchers don’t understand how this works, but it could give important clues to designing emergency gear to help humans collect water in the desert.
Other engineers are studying everything from beetles than can detect forest fires burning 60-miles away to the way flies buzz through the air and how geckoes scamper up and down walls.

They don’t want to build artificial beetles or flies or geckoes. They do want to understand how these creatures do it so they can use the same principles to build things humans can use.
An artificial fly, for instance, could be sent into a collapsed building through passages too small for humans to find and report on survivors buried in the rubble.
We’re not an artificial fly, but it’s time for us to buzz on out of here. 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.

Smoke Detectors

August 19th, 2008 by dstmartin
 
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This is one sound just about guaranteed to get your attention. Today on Engineering Works, we’ll listen to why you hear it, even before the smoke gets in your eyes.

So you settled down on the couch to watch “Friends” last night and forgot all about that pot roast you put in the oven. And the hot pad you left sitting on the hot stove. Have no fear, the smoke detector’s here, right? You may be wrong.

Many people do not realize that their detector is old and needs to be replaced. Engineers study smoke detector failures by staging full-scale fires in residences and have discovered that ionization detectors can take more than twice as long as photoelectric types to detect smoldering fires, often a delay of 15 minutes or more.

About 90 percent of smoke detectors in homes and on the market sense fire and smoke by using an ionization chamber. These detect flaming fires faster than others, but they just aren’t as quick to detect flameless combustion like smoldering fires.

The typical smoke detector in stores is probably the ionization type, although the labeling won’t necessarily tell you that. Photoelectric detectors will often be labeled as such, sometimes with wording about optical sensing.

If you don’t know how old your smoke detector is, or it’s more than eight years old, replace it. Have both photoelectric and ionization detectors installed or purchase a combination model. Place detectors in every bedroom and hallway. Change the batteries at least twice yearly and test detectors regularly. Or forgetting about that hot pad might become a baptism of fire.

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