a glob of nerdishness » Science

Gas upgrade pricing

natevw — Thu, 20 Sep 2007 02:27:56 +0000

Nerdishness comes in many forms, and a certain electrical enginerd friend has got the equations to prove it. His observation: “Since the 10 cent difference between each grade is constant, as gas gets more expensive, that extra 10 cents per gallon makes less of a difference.”

As gas prices go up, the percent increase in gas mileage is unaffected, but the “upgrade fee” for the premium grades goes down. There’s a simple formula and explanation based on your car’s habits and current prices that will let you know if it’s worth the jump. He notes that “the worse your overall gas mileage is, the more potential you have to save money by buying the right grade.”

“Better” recycling?

hjon — Fri, 29 Jun 2007 04:41:37 +0000

Global Resource Corporation (GRC) has a finely tuned microwave which takes plastics and turns them back into oil, gas, and a few leftovers. There’s a video showing the results of putting old tires through this process.

I don’t know if this is necessarily “better” than just recycling plastic the way we do currently, but it certainly provides an alternative as well as a way to reclaim oil that we’ve already used.

[via Slashdot]

Rotating cylinder lift

natevw — Wed, 09 May 2007 05:17:21 +0000

Did you know a rotating cylinder can generate lift? It’s not very efficient, but it has been used to propel a ship across the Atlantic. I learned this strange bit of trivia through an electrical engineering friend who is now a broadcast radio technician. Spending time climbing to the tips of tall radio towers on a regular basis, I guess any source of lift is just cause for excitement.

Lift of a Rotating Cylinder on a NASA education page has the real skinny, but from what I gather (and correct me if I’m wrong) the cylinder needs to be moving “into the wind”, relatively speaking. The key is that the moving surface of the cylinder tends to drag some air along with it. If the bottom is moving against the oncoming stream, it will be slowing the air below while the top stream is helped along. Slower on the bottom, faster up top? Mix in a little Bernoulli and it’s up and away!

Senior Design

hjon — Fri, 13 Apr 2007 06:03:46 +0000

As a manner of explanation for my lack of posts, here is some information about what I’ve been up to.

As part of my engineering degree, I am in the midst of a Senior Design project with two other engineers. We’re working on building an electric vehicle, using a frame from a Senior Design project done 10 years ago (they built a human-powered vehicle, so ours is intended as a next step). The primary purpose behind these vehicles is to reduce pollution caused by taking short in-town trips (tailpipe emissions are worst at a car’s startup, so a lot of short trips in town can be worse, pollution-wise, than a longer trip that allows the engine to warm up and reach its most efficient state). So these vehicles are intended primarily for commuting purposes.

Ok, I think that’s enough explanation for the time-being (if you want more, ask in the comments, and I’ll try to address it in a future post), but here are some pictures of the vehicle that we used for our basic frame.

Here’s a view of the human-powered vehicle before we took it apart (unfortunately, we had already removed the cargo area, so we don’t have any pictures of that):

Here’s a second view:

Here is a picture of the frame after we took it apart:

Finally, a close-up of the steering mechanism used on the wheels so that they tilt and turn: