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Comment Re:Sipping From a Firehose (Score 1) 214

by TheClassic (#27654161) Attached to: How to Charge Your Cellphone Using Wasted Heat

Additionally, such waste heat might not actually be "free" - depending on some of the implementation details.

The engine works by generating heat and then converting it to mechanical motion while dissipating that heat to a cold sink. If you don't "waste" that heat by sending it to a cold sink then the engine operates less efficiently.

Again, it depends on the details - the energy might be "free," or it might just rob the engine of power just as an alternator does. You can't get around the laws of thermodynamics, though...

I'm pretty sure BMW places these in the exhaust manifod (or elsewhere in the exhaust system) where all the heat comes from gases that are indeed waste. Indeed if this were placed within the combustion chamber or conducted heat from it than it would have a negativ impact on the efficiency of the engine. You can use novel methods to convert one form of energy to another without breaking the laws of thermodynamics.

Comment Re:What? (Score 1) 291

by TheClassic (#24220127) Attached to: NASA Needs Urine

"It's difficult to come up with a faux urine, explained NASA's Jim Lewis, the systems manager overseeing development of Orion's potty. 'That's why we depend on collections.'" They can tell my sex, blood type, color of my eyes and hair, my favorite brand of cigarettes and my probability of being obese from a drop of my blood but they can't synthesize urine? Where there heck did things go so wrong?

Actually I'm quite sure they could synthesize it. However, why build a cow when you can get the milk for free? They could spent a ton of money developing synthetic urine, but even then there is no guarantee its going to behave exactly the same. Why not just use the real thing?
Power

Saving Power in your Home Office 285

Posted by CmdrTaco from the something-to-think-about dept.
cweditor writes "Rob Mitchell shows how he measured energy use of all his home office equipment, and then targeted the energy pigs for replacement. With better equipment choices, he'd save $90/year. If you've got more than a couple of computers and printers at home (and if you're a Slashdot reader, you probably do), the savings would be a lot higher. Includes detailed formulas as well as a spreadsheet on monitor energy usage."

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