Issue Date: December 18, 2006
Fuel-cell lights, Fireproof goat, Fluorescent tree
A Christmas tree is the recipient of HIGH-TECHNOLOGY DEVELOPMENTS in one venue this year. In California—where else?—Gov. Arnold Schwarzenegger lit up the Christmas tree at the state capitol this month with an environmentally correct note. First, the tree's 6,500 lights are high-efficiency light-emitting diode (LED) bulbs, which are expected to use only about one-tenth the amount of electricity as would be used by comparable incandescent tree lights.
LEDs do not use a filament to glow nor are they just white lights surrounded by colored glass. The light comes from the movement of electrons across a semiconductor, and the chemical makeup of the semiconductor determines the peak wavelength emitted. Hence the LED's color.
But even more interesting is that these lights are being powered by a 1-kW hydrogen fuel cell. The unit, built by Altergy Systems, uses bottled hydrogen as fuel. The company estimates it will cost about 14.5 cents' worth of hydrogen per hour to power the lights on the tree, compared with about 5.2 cents if it was on the local power grid.
California, however, wasn't the first in its alternative-energy lighting plans. The Christmas tree located in London's Trafalgar Square was powered by a fuel cell in 2004. The GenCore system was capable of providing up to 5 kW of power for the square's tree, which is an annual gift from Norway.
And also in Scandinavia, the town of Gävle, Sweden, has been building a 43-FOOT-TALL CHRISTMAS GOAT out of straw since 1966 to evoke an old Swedish tradition. But 22 times since then, vandals have burned the goat as it stood on the town square.
Last year, even with guards protecting the structure, vandals managed to shoot flaming arrows into the goat, burning it down to its steel frame.
This year, the company Fiber ProTector has stepped up and doused the entire structure in a flame-resistant compound and virtually guaranteed that the goat would not burn. The chemicals are said to be waterproof and snowproof, and town officials are so confident the goat will survive that they have even called off the guards. It sounds almost like a dare.
Undoubtedly the only one of its kind, the CHRISTMAS TREE pictured here is about the size of the period at the end of this sentence. It's the artful sort of thing that Patrick Hickey, director of Edinburgh-based LUX Biotechnology, conjures up when he doodles with the laser of his scanning confocal microscope.
"I did this at the end of the day, after carrying out some bleaching experiments on a new fluorescent protein," he says. The protein is a recombinant version of the green fluorescent protein (GFP) behind the glow of the Sea Pansy coral. Hickey's company sells fluorescent proteins to scientists, and his clients like to know how much light these proteins can take before going dark for good.
Hence the bleaching experiments. To do these, Hickey paints GFP solutions onto glass coverslips and measures how much laser energy it takes to knock the protein's lights out. Hunched over his microscope one day, the holiday spirit evidently possessed Hickey. With a freshly GFP-painted coverslip, he steered his blue-green argon laser to this spot, then that one, each time zapping the location for 5 seconds. When he was finished, Hickey had bleached into existence a teeny-tiny Christmas tree.
At first, it looked more like the remains of a forest fire than a festive specimen of arborous laser art. "The raw data is black and white," Hickey notes. So he used an image processor to assign shades of gray to different colors and ended up with a "season's greetings" image specially suited for the molecularly minded among us.
- Chemical & Engineering News
- ISSN 0009-2347
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