Archive for May, 2005

Extreme Textiles

May 25th, 2005 by dstmartin

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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.


Jet Engines

May 18th, 2005 by dstmartin

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Fasten your seatbelts. We’re leavin’ on a jet plane. Today. On Engineering Works.

We all know something about jet planes. Long-distance business trip or vacation in Italy, jet airliners get you there. Quicker than old-fashioned propeller-driven planes. But how do those jet engines move the plane?

The idea behind jet engines is pretty simple. Think back to your high school physics. It’s Newton’s third law. For every action, there is an equal and opposite reaction. Simple. Making it work in a jet engine is complicated.

Think of a jet engine as a tube that breathes air. A fan at the front of the tube sucks air into a compressor — rows of spinning blades that squeeze the air into the combustion chamber. Spray in jet fuel, add a spark and — phwooom! First, the burning gases push into a turbine. Think of a row of high-tech metal pinwheels. The hot gases spin the pinwheels, which power the rest of the engine. But that’s not all.
After spinning the turbine, the gases roar out a nozzle at the back of the engine. This powerful thrust pushes the engine and the plane forward. An equal and opposite reaction.

Jet engines and jet airplanes have been around longer than most of us think. An engineer in England patented the first jet engine design in 1928. And the first jet-powered airplane flew in Germany, in 1939.

You can unfasten your seatbelts now. Thanks for flying with Engineering Works!


Plastic and steel

May 11th, 2005 by dstmartin

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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.


Smart Shoes

May 4th, 2005 by dstmartin

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Athletic equipment is getting more high-tech all the time. We’ll take a look at some. Today. On Engineering Works!

Running shoes became a fashion statement a long time ago. Even if the only running you do is to get in out of the rain. Serious runners, though, take their shoes – seriously. Equipment makers have responded with gas-filled bubbles for padding, shock absorbers and even springs. All aimed at making runners faster and more comfortable.

Running shoes are big business – 15-billion-dollars a year big. So it was bound to happen. One running shoe maker is designing new shoes with a microprocessor inside. The idea is to help the shoe adapt itself to individual runners’ running styles and adjust continuously to the environment it’s running through. Here’s how it works. A dime-sized sensor in the heel takes 20-thousand readings every second. Then the microprocessor makes 10-thousand calculations to control a tiny electric motor as it adjusts the shoe to what’s going on.

The motor manipulates a cable and small steel brackets in the shoe’s heel that adjust how its cushioning responds – harder or softer – to the surface under it and the way the runner wearing it is running. The whole thing is powered by a tiny watch battery that’ll give you about 100 hours on the road. Imagine. A running shoe with an instruction manual. Including how to change the battery.

It’s time for us to hit the road. See you next time.