Moldable Magnets

leb writes, "What if researchers could create a tough, lightweight, moldable material, with "tunable" magnetic properties? Molded into different shapes, such a material might someday prove useful for high-density data storage, anti-static coatings for aircraft or spacecraft, and a host of other applications. A first step toward tunable, ceramic magnets is reported by a group of researchers from University of Toronto. "

Comments

Space Station

[Dolohov]

Reading over the description of the process, the article just -screamed- "Low Gravity" to me. If I recall correctly, early plans for the International Space Station included various materials furnaces that could probably be used for something like this. Basically, they were just flying toasters -- you would load the material, and it would be heated and analyzed according to some pretty intricate heating gradients and timings.

I've no idea if that's still in the plan, but the idea is still viable, I'd imagine, and would definitely help study the structure of the material, if not gain insight into ways to improve it.

magnetic chips

[chinoodle]

Cambridge uni boffins have just announced a magnetic chip design supposedly 40 odd thousand times more power efficient than the silicon flavour. This BBC article has the full story.

Old News, look at my 'Frig door

[Cy Guy]

What's the big deal? I've got a whole collection of molded magnets on my refrigerator door. I've got them in the shape of plumbers vans, pizzas, even mickey mouse.

With all the "Magnets as healing" crap ...

[Pfhreakaz0id]

I'm ready for the "Magna-condom": See Your Sexual Powers Increase Twentyfold! Let the scientifically acclaimed powers of magnets regain some of the "attraction" you've lost! "I can't believe it," said 62-year-old Ed Powers. "I haven't felt this randy since I was 17! I pop it on and 'Poof, we have liftoff, if ya know what I'm saying!'" Only $29.95 for a 6 pack! CALL NOW, 1-800-GET-LIFT
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Re:Transformers

[tzanger]

Each transformer has a unique resonant frequency - the one it transforms most efficiently at. This is also the least "noisy" frequency to convert at - the waveform makes it through without looking like a lawnmower went over it. If we can tune these things to 50 or 60hz that would be.. well.. awesome.

No, no no... Transformers are optimized for specific frequencies because there is no (known) way to have a given ferrite material and transformer construction work well at all frequencies. Big power transformers use laminated "sheets" of metal to store lots of flux and keep eddy currents down. Unfortunately to get any decent power out of these you need to make 'em big 'cause there's a WHACK of flux being shoved around at 50/60Hz and therefore a lot of steel required to store the flux.

Switchmode power supplies get bigger power ratings because they work at far higher frequencies (typically 100-300kHz). At these frequencies there isn't a lot of flux at any one time so you can get away with tiny transformers for the same power rating. (picture it as draining a pool with a 1000L bucket in a couple dozen passes (60Hz) as opposed to using a 355mL pop can a couple bazillion times in the same time period (300kHz). They both get the water out, but one does it more efficiently.) They also don't use laminated sheets of steel, but rather a pressed ferrite "dust" 'cause (IIRC) it's cheaper and lighter.

The reason a waveform looks "like a lawnmower went over it" when you put it through the wrong transformer is that you are most likely either driving it into saturation (the top-right and bottom-left-most parts of the B-H curve) or you're wayyyyyyy out of range on the frequency which causes tons of losses in the power transfer and thus your output waveform won't look much like the input.

Thus concluding the short lesson on transformers, if anyone has any questions, please feel free to email. Similarly if you feel the need to correct, by all means do so. :-)

Re:EM bad?

[re-geeked]

Puhleeez!

Cell phones have been suggested to cause tumors, not PROVEN.

And the EM field dangers are likely even more dubious. There's a great old episode of Frontline on how the research that spawned these fears is a spectacular example of flawed analysis.

The best line of the Frontline is when a more clueful scientist points out that outside of a few meters proximity the level of radiation coming from power lines is bupkus compared to that coming from the sun and earth:

"It's like your neighbor calling you up during a windstorm and saying 'Your cat is breathing on my tree.'"