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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. "
Just one more piece of the puzzle for Canada's impending world domination... But seriously. I wonder if means that someone will actually invent the "chick magnet".
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.
They've managed to embed iron filings in rubber. Forgive me but is this really new?
Except in this case, they have embedded the iron (and thus the magnetic properties) in the molecules themselves, as opposed to simply mixing it in, which was undoubtedly the case with your toy.
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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.
henry [ w i r e t r a p . n e t ]
Well, first of all, an anti-static coating needs to be conductive, magetic properties are irrelevant for static control.
Second, they say the material has to be heated to 500 degrees Celsius as part of the fabrication procedure. Are they planning to bake entire airplanes and spacecraft at 500 degrees?
Of course, if they manage to make iron nanoclusters with the exact number of atoms to optimize magnetic properties, this would be interesting for data storage. Expect to see cheaper hardisks with more capacity in the future. But bigger, cheaper HDs cannot be called "news" anymore, can they?
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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.
Work for Change & GET PAID!
Actually, you have this backwards. Hard Drives have not been increasing speed as fast as processors, in fact they are falling way behind in terms of speed. Most HD manufacturers are nearly totally dedicated on making their product bigger, not faster. Worse, HDs are still something like 10 orders of a magnitude slower than main memory, we aren't going to see them replacing main memory anytime in the near future.
I read the internet for the articles.
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Scientists at a top research facility have theorized on a possible application of the use of this magnetic material as a random access stroage medium in computers. Tiny doughnut-shaped rings of the material would be located at every intersection in a grid of thin wires strung along two axes. Any single magnetic ring can be addressed via two wires (one on each axis). A third wire will wind its way through all of the magnetic rings along a diagonal pattern. To store a bit, the x,y wires will receive a large pulse of current. The polarity of this pulse determines wheather a '1' or a '0' is to be stored in the tiny ring. To read the bit back, Another pulse (always in the same polarity is sent down the x,y axes again). Depending on the currently magnetized state of the ring, a differing current pulse level will be detected in the 3rd wire which can be used to interpret the stored value. Since this pulse may destroy the bit value stored in the magnetic ring, the value just read must be written back immediately to the ring. This exciting new technology means that someday, computers may have many planes of vast grids of these tiny magnetic beads as their primary work storage. And will shrink the size computers down greatly while making them much faster. Scientists have yet to name this new technology and will turn to the public for ideas on this matter. Yes folks, it's an exciting time to be alive!
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. :-)
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.'"
"You can't get something for nothing." - my grandfather, on the stock market and Reaganomics.