Slashdot Mirror
Self-Cleaning Buildings to Fight Smog
bryan8m writes "Using technology already available for self-cleaning windows and bathroom tiles, scientists hope to paint up cities with materials that dissolve and wash away pollutants when exposed to sun and rain. The idea: UV rays hitting the titanium dioxide coated cement and concrete trigger a catalytic reaction that destroys the molecules of pollutants, including nitrogen oxides."
That's much too expensive. Compare the costs of TiO2 and a solar panel and you'll see for yourself.
But of course it would be much better for the environment.
See pictures of tits
Keyword here is catalytic reaction. A catalyst is a substance that initiates a chemical reaction but is not consumed itself in the reaction. The catalyst in the paint would stay in existence, it would simply break down pollutants when they came in contact with the material when UV radiation was hitting it. As long as the pollutants were reduced to innocuous materials there wouldn't be an issue with toxic waste disposal.
I'm a loner Dottie, a Rebel.
It's not about cleaner houses, it's about cleaner air!
They try to make a house work like a tree to actively reduce the amount of pollution in the air. That the house stays clean is just a nice side-effect
See pictures of tits
Now, that high power solid-state switches ( hence, power converters ) are becoming do-able, is there any way we can start putting high-voltage DC on our power grids?
DC is horribly inefficient at delivering power. Besides, high voltage is high voltage. Power lines run just under the voltage needed to ionize the air. Once you ionize the air, then you set up currents, and those currents are sucking power, power that isn't being delivered, and could have been charged for.
What about other pollutants? What about every pollutant? Look, I'm not nearly qualified to get into the science of this, but there is a lot to account for in this kind of research. Throw some plastic bags and some newspapers in the incinerator, and one of the byproducts will likely be dioxins, one of the most toxic substances there is. Dangerous non-linear consequences to waste/pollution "solutions" are frequent, because the research is often cursory at best, and people want their particular "solution" to succeed.
Of course, this could be completely safe. But the article did not exactly inspire joyful optimism in me. When we try to slap a band aid on an obvious problem (rampant air pollution), we often end up with serious unexpected new problems.
They are not a magical answer to all our polution, and energy needs.
Where do you keep your car? Most likely in a garage or car port. Either way, it's not a place with much in the way of ambient light. You'll not be doing much charging at home. In urban areas, most parking is in large, multi-level (and often underground) structures, where there is a similar absence of sunlight. So your car won't be doing any charging while you're at the office.
You're thus limited to the charging your solar cells could do while actually in the process of your commute. The hours most people drive are morning and evening, when the shallow angle of the sun produce sub-optimal light reception for solar cells.
In other words, for the way commuting works now, solar cells are a waste - at least in urban areas, where there is the most need for clean energy.
-
By the way, "kinetic" watches have been around for a long time. They use a ratcheted weight system that winds the spring whenever the tilt of the watch is changed, which happens a lot during the day for an average wearer.
± 29 dB
Can I put this stuff on my car
4 EBB84D7DD0CD39BAB99/xDocTable_News/Tab_Overview/Te chnologyClassID0/MarketID0/TechnologyID0/Applicati onID0/ProductID0/up1/SubSiteID0
t on.html
Yes kind of: http://www.engelhard.com/Lang1/xDocID7A06011F50F1
Instead of CARB trying to steal/criminalize classic cars and sell the valuable energy credits to Oil companies and other polluters.
http://www.hotrod.com/projectbuild/42840/
http://www.cato.org/pubs/regulation/reg17n3-johns
They could have a program where they replace anyone's radiator for free with one with the abve coating - Some newer cars are so low emission already that with these radiators they would become NEVs - Negative Emission Vehicles.
I wonder how many billions that kind of program would have cost - sorry forgot we don't have any to spare for important long term issues because we need it all to line the pockets of the cronies.
I admit for constant-speed rotating machinery, its damn hard to beat 3-phase AC.
I have noted several companies are now investigating DC again as new devices are becoming available which will make high-power DC-DC converters economically do-able. Here's an example of Toshiba's work in this arena.
They are trying to get around various things, AC losses, Power factor corrections, and a few other quirks of AC transmission.
I am noting too that if the high voltage DC is exposed to air, yes it will set up a small current. So does AC. We call it "corona discharge", but in the case of AC, this leakage consists of roughly equal amounts of positive and negative ions and they cancel without doing anything useful. If we are going to lose the energy anyway, might as well have it do some useful work and clean the air.
I am hoping by posting this onto Slashdot, maybe another power engineer out there will see it post back some comments. I don't deal with power engineering at this level, but I have seen some of the big guys reports detailing advances in solid state switches driving megawatt-scale power conversion for use in DC transmission lines and superconductor transmission lines.
If there is a cute little trick we can pull off to build a big air purifier for Los Angeles, I would sure like to see it started.
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
One car puts out nothing copared to a single power plant.
However. There's more cars than power plants, to the order of millions. And cars, individually, are NOT pollution-efficient. Power plants already have pollution-cutting measures, in general. Private cars are the EASIEST way to reduce emissions - and people love to ignore that.
There are water-based plants that work like batteries, when usage is below production they pump water into a higher basin, when the city needs more power than the normal plants can supply it starts running the water from the top through generators (it's not 100% efficient, sure but it's better than not using the surplus power at all). That's meant to allow for saving up energy when it's not needed for the peaks. If you can produce more power in the evening but you need it in the afternoon, you let those plants "charge" during the evening and discharge during afternoon.
Justice is the sheep getting arrested while an impartial judge declares the vote void.
Titanium dioxide has been used in paint for a long time, and is one of the two chemicals most used as a pigment in white paint. (The other is zinc oxide.) Producing a bit more than we already are is not likely to be a significant problem.
Contribute to civilization: ari.aynrand.org/donate
You're wrong. Many utilities maintain so called "Peak Load" plants (often diesel generators). These plants are switched on to accommodate heavy load, then turned off once they are no longer required (diesel is expensive).
Wouldn't it be smarter to cover the buildings with solar panels, use that to power half the building and cut down of the amount of smog created by the power plants instead? Your car puts out NOTHING compared to a 250Mw coal plant.
Actually from what I read, I think one place might of been in HomePower mag and/or Solar Today mag , was that vehicles are the single biggest contributers to manmade greenhouse gases. A simple remedy for this though is Biodiesel . Without modification diesel engines can run on biodiesel. Actually Rudolph Diesel the designer of the diesel engine designed it to run on most any vegetable oil. And because the plants used to make the oil soak up carbon dioxide they are carbon neutral. It's not so much how much one vehicle puts out as it is the total of all vehicles.
However more building should include solar power in their design, active and passive. One way as you've stated is pv panels. Another way is a thin film that's being developed that can be applied to windows and the sides of building to generate solar power. Another method of power generation are wind genies, wind generators.
FalconShould there be a Law?
I know that they have at least three running into Detroit.
The trick was that they replaced nine undereground power lines, that were already oil-cooled. Basically, the continuing cost for the LN2 is less than the pumps needed to circulate the oil.
The three new cables contain only 250 pounds of superconductor, yet they will be able to carry just as much current as the 18,000 pounds of copper in the nine cables they replace.
The trick is, you don't need to pump the LN2, as it just boils off, you just have to keep it 'topped off'. The cables are heavily insulated, so the boil off rate is actually low, as the cables don't produce any heat, whereas the copper lines did.
I remember reading that they actually made money on the replacement, as 18,000 pounds of copper is quite a chunck of change.
A source, the rest I'm working off of remembered articles that aren't easily found on the internet today.
I'll admit, it's going to be a while before they bother running a superconducting line to your neighborhood, but for the main trunks out of power stations, into cities, or other major distibution centers, it makes sense.
I don't read AC A human right