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Water Now More Awesome Than Previously Thought
Dan writes "Wired has a great article about a guy who thinks we can provide unlimited energy , accelerate crop growth, desalinize and purify drinking water, obtain health benefits and provide air conditioning, all by pumping up water from the depths of the ocean."
The efficiency of these system is extremely low because the temperature difference is so miniscule. For thermodynamic efficiency purposes temperatures are measured in Kelvin and temperature differences are only a few percent. The maximum efficiency of these plants in an ideal world is only 6%. When you account for the very large amounts of energy needed to pump huge volumes of water, the real efficiency is only 2-3%. This FAQ covers this and other issues.
Yes, you can get energy, but not much.
Two wrongs don't make a right, but three lefts do.
Hydrothermal events (http://en.wikipedia.org/wiki/Hydrothermal_vent) exist in the oceans and pump out water at temperatures very close to, if not, at boiling temperatures. Pumping warm water back into the ocean is not going to make that much of a difference on the oceans.
I think he is counting on inertia, or some more subtle effect I can't think of.
The articale mentions that once the system is primed, it takes very little energy to keep pumping.
Think about it. You're not pumping water up into the air, you're pumping water above other water. Without any pumping, the water will automatically lift the water to, you guessed it, sea level. You only neet to lift it the extra 30 feet to your beach side farm.
Getting the system started probably takes a lot of power as you have to get all the water in your pipe moving fast enough so the water won't warm up by exchanging heat with the outside water, but one it's moving, inertia will help you keep going. You only need to make up for friction, and for the fact that cold water is slightly less dense.
Then again the article mentions that the pipe acts like a siphon, so maybe there is some other effect I can't think of. Maybe the decreased pressure because of the pump makes water freeze and therefore rise? dunno.
The idea has been around a long time but then so has John Craven. Toronto is using the waters of Lake Ontario to provide air conditioning for a big slice of downtown realestate. The big problem with the Great Lakes is the needs of the urban sprawl that circles the Lakes' shores is putting stress on the resource, not to mention the political fray ensuing from many plans to alter the in/out flow of the watershed feeding the lakes. Being Canadian and watching the growing need for water in the US just makes me feel like we're gonna be on top of the quality of life index for a long time to come.
"Academicians are more likely to share each other's toothbrush than each other's nomenclature."
Cohen
The same sort of thing exists in Toronto.
I have never heard of an "ocean engineer," as opposed to chemical engineer or electrical engineer.
Ocean Engineering is a field of civil engineering, which is concerned with construction on coasts or under water. Offshore oil rigs are designed by Ocean Engineers, for example.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
Well, yes. Yes I have,,,
:-)
The poster's exactly right. Applying both ice and heat to an injury manage the circulation to the area.
When you have an acute injury, say, a sprained ankle, you get an inflammatory response -- swelling. That's nature's way of splinting and immobilizing the injury. That problem is that all that swelling later turns to scar tissue, in essence, crippling you afterwards.
What you're trying to do is to use cold to decrease circulation during the acute phase of an injury (to reduce swelling), and to use heat and motion to increase circulation during the chronic phase (to help break up scarring and create new muscle and bone). The rule of thumb is ice for the first three days, then heat, but really, you want to ice as long as there's heat coming off the injury.
Both ice and heat will make you feel better. In my experience, ice is initially less comfortable, but WAY more effective in the end. And, ice combined with Aleve is even better.
As an aside, ultrasound therapy works the same way as heat, albeit in a more focused and comfortable way. You never want to use it acutely, but for things like old hamstring injuries, it's the freaking bomb.
During rehab, (and frankly, if you're playing competitively, you're ALWAYS in rehab) you end up using both heat and cold. Usually, that's heat beforehand (to increase flexibility and circulation) and cold afterwards (to reduce inflamation from the trauma to old injuries). After a while, you just get used to the routine -- although spending a half hour with your balls in an ice whirlpool is never any fun.
No, I'm not a doctor or a physical therapist, but after a broken leg, a blown hamstring, one remaining ligament between two ankles, twenty five years in the cage, and a trip playing in the World Games, you get to know these things...