Wireless power

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Powercast (formerly Firefly Power Technologies, and spin-off based on University of Pittsburgh research) made a splash at CES this year with their dime-sized receiver that harvests RF energy from a nearby wall-wart transmitter. Based on their patent and related tech from PITT, the technology looks pretty darned simple (so simple I’m surprised there’s not prior art, but then this isn’t my field). It’s basically just an antenna with a bunch of taps, each tap consisting of an inductor to resonate with the desired RF frequency and a rectifying diode to turn the energy into DC. That DC voltage is integrated across a series of capacitors, and stored in another capacitor.

I’ve not seen any detailed specs on how efficiency drops off with range from the transmitter, though a Businesses 2.0 write-up claims their range is only about 3 feet, with voltages too small for laptops but good enough for small devices. Their tech has also been tested for recharging wireless sensors at the Pittsburgh Zoo, and Philips is apparently coming out with a wirelessly-powered lightstick using the technology later this year.

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Flash crowds in high schools

From an NPR interview with Principal Ed Kovochich, who has banned cell phones in his Milwaukee high school because they’ve been causing flash crowds at what would otherwise have been a simple one-on-one fight:

Quite a bit of the school was text messaged where the fight was taking place, and soon there were hundreds, and they were cheering and jeering and usually you get into that mob violence mentality. And suddenly what was 3-on-1 became 3-on-2 and then 3-on-3 and etc. and before you knew it we had a lot of kids fighting.

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A pill for everything

From an article on a study that shows women display increased hormone levels when exposed to chemicals found in male sweat:

One implication of the finding is that there may be better ways to raise cortisol levels in patients with diseases such as Addison’s disease, which is characterized by low cortisol. Instead of giving the hormone in pill form, which has side effects such as ulcers and weight gain, “a potential therapeutic mechanism whereby merely smelling synthesized or purified human chemosignals may be used to modify endocrine balance,” the authors wrote.

How distinctly American, distilling sex into pill form so we can have the benefits without all the messy side effects… (thanks to Janie for the link.)

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