現在地 HOME > 掲示板
> Ψ空耳の丘Ψ３１ > 365.html
★阿修羅♪
|
現在地 HOME > 掲示板
> Ψ空耳の丘Ψ３１ > 365.html
★阿修羅♪
|
|
(回答先: 「水力携帯電話」が可能に？――カナダの研究者が発表【Wired News】 投稿者 エイドリアン 日時 2003 年 10 月 22 日 18:00:26)
http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2003/10/20/welec20.xml&sSheet=/news/2003/10/20/ixworld.html
/welec20.xml&sSheet=/news/2003/10/20/ixworld.html0/20/
【Scientists make electricity from tap water】
By Roger Highfield, Science Editor
(Filed: 20/10/2003)
Scientists have discovered a new way of generating electricity using water, the first innovatory method for 200 years.
A team of Canadian researchers has found that an electrical current can be produced between the ends of a microscopic channel when a fluid flows through it.
The technique offers a potential source of clean, non-polluting electric power with a variety of possible uses, ranging from powering small electronic devices such as calculators or mobile phones to vast stations that can contribute to the national grid.
The method, which harnesses the "electrokinetic" properties of liquids such as ordinary tap water when they are pumped through microscopic channels, is described today in the Institute of Physics publication Journal of Micromechanics and Microengineering.
The research has been led by Prof Daniel Kwok and Prof Larry Kostiuk at the University of Alberta. They suggest that a mobile phone could be powered by squirting water at high pressure through an array of such channels.
Prof Kostiuk said: "This discovery has a huge number of possible applications. It's possible that it could be a new alternative energy source to rival wind and solar power, but this would need huge bodies of water to work on a commercial scale.
"Hydrocarbon fuels are still the best source of energy but they're fast running out and so new options like this one could be vital in the future."
The energy source for this device is the work done to push the liquid through the channel. Although the power generated from a single channel is tiny, millions of parallel channels can be used to increase the output.
The channels can be made from any non-conducting material such as glass, plastics, rocks or ceramics. Standard commercial filters made of these materials already have the millions of channels that can be used.
The key to the phenomenon is the way that charges naturally separate at the interface between the surface of a channel and a fluid. Scientists believe that this occurs because minute parts of the solid of one charge (either positive or negative) dissolve into the water. As a result, the surface becomes charged.
Opposite-charged ions (charged atoms) in the liquid are attracted to it, while like-charged ions are repelled, resulting in a thin liquid layer with a net charge, called the Electric Double Layer, measuring a few billionths to a few millionths of a metre across.
The team constructed a channel with a diameter similar to the distance across the layer and forced liquid through this channel. When a fluid, such as water which naturally contains an equal number of oppositely charged ions, is forced down the channel, a charge separation occurs.
The ions that have a charge opposite to the solid are preferentially attracted into the channel (remembering that opposite charges attract each other) and transported to the far end. The ions of the same charge as the solid are preferentially left behind at the inlet side of the channel.
Therefore, the liquid at the two ends of the channel have opposite charges. This produces a voltage difference. If conducting electrodes are placed at the two ends of the channel and connected by a wire, then current flows and electricity is produced.
A typical setup using a ceramic filter and tap water can produce 10 volts and the current depends on the size of the filter. Since large water pressures are not needed, natural flows of water can be harnessed. These could include tidal water flows, underground aquifers, dammed water, drinking water currently being filtered by utilities companies to improve its clarity, and rain falling from roofs.
題名には必ず「阿修羅さんへ」と記述してください。