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Comment: Re:lettice under LED grow lights? (Score 1) 129 129

GaN-based LED's have only been commercially available since 1994, and only recently at a reasonable efficiency and price. Using LED's is quite different from using tungsten filament or gas discharge lamps (aka flourescent lamps).

As mentioned previously in these comments, plants only absorb a small fraction of the solar irradiation. For example, chlorophyll, the dye molecule used by many plants, only absorbs significantly in relatively narrow bands of the blue and red, corresponding to 2% of the total solar irradiant power.

It turns out that the bandwidth of these absorption peaks matches quite closely with the bandwidths of blue and red LED's operating near room temperature. Thus, even with 20% efficient LEDs the total power-to-plant-product efficiency can likely approach 100%. If you replace the plants with standard 18% efficient solar cells, you could feasibly have several layers of plants powered by the same footprint, although at a greatly increased capital cost.

If you add in the improved control over germination and growth afforded by an enclosed and highly-regulated environment, the economics might begin to make sense, especially considering the long lifetime of color-pure LED's (much longer than phosphor-converted LED's).

Comment: Re:I do not think they qualified as 'organic' (Score 1) 129 129

Almost all of the pictures look like purple + red to me. There's one picture that looks like it has a fraction of white lights. However, most LED white lights are actually blue/uv + yellow.

Thus, you seem to be jumping to conclusions. If anything, you're point about plants only being able to use 1% of the power from sunlight suggests that they might be on to something.

Comment: Re:So does this qualify as 'organic'? (Score 1) 129 129

Parent deserves to be modded up.

What ultimately matters here is economics. There is obviously a huge capital cost involved here, but it very well may be merited, especially for growing delicate species. And the more these systems are utilized, the more economy of scale will make it economical for more general applications.

I am a bit put off by the lack of costs in the article, but I guess that is to be expected from a press release. Since this is still in research stages, it is almost certainly not yet economical. However, if it is even within a factor of 10x of breakeven over a ~20 year time frame (including capital costs, but replacing the researchers' salaries with technicians'), then this could be a significant player in the future.

Comment: Re:It's feasible, but not practical (Score 1) 36 36

I agree that super-conductor based magnetic levitation systems have questionable economics, at least with the current state of high-temperature superconductors. However, that hasn't prevented Maglev train test-tracks from being built.

In contrast, standard active magnetic levitation bearings are very economically viable, particularly in applications requiring extremely high rotational speeds, long operating times, and low oil contamination, e.g. turbomolecular vacuum pumps.

Comment: Re: Does it matter? (Score 1) 668 668

Unfortunately that's not the case. Homeopathic remedies often do have content other than water, but in uncontrolled and untested doses, sometimes resulting in dangerous effects. See Zicam nose spray, for example. The FDA finally stepped in after hundreds or thousands of people lost there senses of smell and taste.

Comment: Microfluidics? (Score 4, Interesting) 67 67

The project looks interesting from an academic perspective, but the stated application to biological microfluidics seems ridiculous when it requires the droplets to be filled with magnetic materials that could potentially compromise any test you might want to perform.

Microfluidic channels are fairly easy to produce using traditional lithography, and a simple water pump produces all of the motion necessary. It's difficult to see how this really improves upon that model.

Comment: Re: Vinyl (Score 2) 260 260

That would be incredible if increasing the pressure caused water to boil. I think there's a perpetual motion machine in there somewhere.

(Lowering the pressure could cause water to boil, but not increasing it. Maybe you meant the heat from friction, but I doubt there's that much heat being generated.)

Reality must take precedence over public relations, for Mother Nature cannot be fooled. -- R.P. Feynman

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