Goodbye Old Site, Hello Awesome New One

November 09, 2009

Back in early 2008 I quietly panicked trying to come up with a name for my new blog or "column" as I told people of a certain age. How about Super Duper Sustainable something-or-other? With the deadline closing in, Super Duper Sustainable Tech Stuff it was.

Now, fortunately, it's time to shed the old unwieldy blog skin. The Discovery News crew--reporters, bloggers, producers, tech whizzes--just moved to a different location online. Our new digs make the previous pages look like Geocities in comparison. Yeah, it's that awesome.

So please bookmark DiscoveryNews.com, where it will be easier to find what you're looking for, get your Discovery News tech fix, view archived posts, and even keep up with my sustainable stuff using a handy RSS feed. The site gives super duper a whole new meaning.

See you there!

Photo Credit: Rick Audet.

Building a Better Mosquito Trap

November 06, 2009

UC Davis scientists who have been sussing out mosquitoes’ sniffers have made a discovery that could lead to really killer bug traps.

Chemical ecologists Walter Leal and Zain Syed identified a chemical called nonanal in humans—and, crucially, birds—that serves as a signal for the Culex species of mosquito. Nonanal is a metabolic product of fatty acid, and while it's unclear what its function is for us, for hungry mosquitoes it's like a "BITE HERE" sign.

The scientists tested hundreds of compounds that birds and humans have and found that sensitive mosquito antennae can detect even minute amounts of nonanal. They used the chemical as a lure and waited to see how bloodsucking, West-Nile-Virus carrying Culex mosquitoes would react.

Leal says when they added carbon dioxide to nonanal, the combo attracted more mosquitoes than each of them combined. A heavy duty CO2 trap they put in nearby Yolo County caught around 2,000 of mosquitoes nightly. Leal says synthetic nonanal is dirt cheap to produce and he thinks that traps with it might be available next year. Next, the plan is to test other mosquito species' responses to the combo.

Sadly, an effective DEET alternative is still elusive. Blocking nonanal and CO2 means mosquitoes will find a different signal, Leal reports. He also told me that if he had an effective repellent that decreased human attraction to mosquitoes, he'd be first in line. "They give me a tremendous allergic reaction."

Photo: UC Davis chemical ecologists Walter Leal (left) and Zain Syed in the lab. Credit: Kathy Keatley Garvey/UC Davis Department of Entomology.

Supersurface Could Shrink Power Plants

November 04, 2009

Sounds trippy, but it's true: mushrooms and lotus leaves are the inspiration for a superhydrophobic surface created by Duke University scientists that has the potential to make power plants super-efficient.

"In power plants, the majority of the space is taken up by bulky condensers," says Chuan-Hua Chen, assistant professor of mechanical engineering and materials science at Duke. Conventional condensers, which are needed to reject heat in power plants' cooling systems, rely on slick coatings and gravity. Chen and his team turned to nature for better ideas.

Water rolls right off a lotus leaf because its rough surface traps air under the droplets. When a mushroom reproduces, the discharge of spores is actually powered by the energy released when dew droplets merge on them. To replicate these effects, the scientists etched pillars a few microns tall into silicon and added carbon nanotubes that mimic the rough lotus leaf. When cooled, the synthetic surface causes water droplets to form quickly and jump--like a balloon bouncing off your hand.

Chen says this makes a condenser so efficient that its size could be reduced as much as 10 times what it is now. Plus, the surface doesn't need gravity to work so it could even be used in outer space. A Duke University video shows it in action:

Grad student Jonathan Boreyko is leading work on building miniaturized condensers with the superhydrophobic surface. Chen says that while there are ways to make such surfaces inexpensively, the focus now is on durability. With supersurfaces, we could get more out of the power plants we've already got, making each drop truly count.

Photo: Chuan-Hua Chen (right) and Jonathan Boreyko (left), demonstrate the superhydrophobic surface, located under the pipette. Credit: Duke University Photography.

Scaling Up Saharan Solar

November 02, 2009

The idea has been thrown around for a while: Let's put a bunch of mirrors--the most ever!--in the desert to provide massive amounts of electricity to faraway places. A newly-formalized consortium is going to do just that, in the Sahara Desert.

Twelve European businesses that form the Desertec Industrial Initiative consortium just signed a pact on Friday in Munich to erect parabolic mirrors on more than 6,500 square miles in the desert. The mirrors will concentrate the sun's rays on giant water containers that will power steam turbines, generating electricity to be transported using high-voltage direct current transmission lines. Tanks containing molten salt will temporarily store excess heat from day. Similar solar projects exist, but this would be the first on such a scale.

The Desertec project plans to provide 15 percent of continental Europe's energy needs by 2050. Several North African countries are interested in joining the consortium and Desertec expects to deliver electricity to local African consumers as well. The technical and financial details of the project, which was first announced two years ago, will be ironed out by 2012 with power deliveries to Europe starting three years later. While I can hardly fathom the crazy financing required, advancements in solar technology make me optimistic that Desertec won't turn out to be a mirage.

Photo Credit: Solar Millennium AG.

Traffic Control for Turtles

October 29, 2009

Scientists have been tagging turtles for a little while to see where they go, but a new combined effort could mean fewer turtle tragedies in the open water.

Juvenile loggerhead turtles, which are a threatened species, can unintentionally become bycatch on fishing vessels. In the fall, sometimes they enter water that's too cold and become stranded. Researchers from the U.S. Northeast Fisheries Science Center in Woods Hole, Massachusetts, are hot on the turtle trail, tracking their movements to better understand their behavior so fishermen can avoid them.

Working with support from the Atlantic sea scallop fishing industry, the NEFSC captured two juvenile turtles in August, attached satellite-linked tags to their carapaces, and has been tracking their movements since (they're off the coast of North Carolina now). The scientists also sent a remotely operated vehicle or ROV into the ocean to get visuals on turtle movements in the wild--the first time this has been done, according to the FEFSC. Here's a cool underwater video showing an ROV-view of a young loggerhead turtle.

The hope is that this pilot project leads to a larger turtle behavior study, as well as better fishing gear technology that prevents turtles from getting caught. That way we'll be able to keep on finding Nemo.

Photo: Attaching a satellite-linked data logger. Credit: Eric Matzen, NEFSC/NOAA.

Rounding Out Shelter Design

October 27, 2009

Recently the winner of a shelter design contest organized by the Guggenheim Museum and Google's 3-D modeling arm SketchUp was announced--a Danish tidal sea space. But a finalist's garbage-transportation shelter really captured my imagination.

The Design It: Shelter Competition asked entrants to design simple off-grid small shelters where a person could study and sleep. It could be anywhere on Earth as long as the plans didn't require removing any existing structures.

Slovenian architect Alexander Niño Ruiz designed a circular, functional rolling shelter for waste-collectors in Bogotá. Thousands of families in the Colombian city gather waste for recycling and sadly tend to find refuge from the elements in the very materials they pick up. Ruiz's corrugated metal barrels nest to form rolling storage. At night, the reflective wheel expands to become a protective space. While I'm not sure how easy--and inexpensive--it would be to construct one of these from scrap materials, I hope Ruiz puts his idea into motion.

Here's a video with more details about the Waste-Pickers Shelter:

Image: Rendering of a Waste-pickers shelter in Bogota at night. Credit: Alexander Niño Ruiz.

When Is Bamboo...Rayon?

October 23, 2009

I've had the bamboo fiber pulled over my eyes. Following a settlement with a clothing maker, the Federal Trade Commission announced that fabrics made from processed bamboo can't be pedaled as green--they're as synthetic as the rayon shirt hiding in your closet.

Under the FTC's settlement terms, retailer Bamboosa agreed not to make any environmental claims about its bamboo textiles being biodegradable, antimicrobial, and wholly made from bamboo fiber unless they could be backed up with reliable evidence. (Bamboosa's site still had green claims when I checked, though.)

Are there actually any green bamboo fabrics? An FTC advisory to consumers says not if they feel soft: "They are made using toxic chemicals in a process that releases pollutants into the air. Extracting bamboo fibers is expensive and time-consuming, and textiles made just from bamboo fiber don't feel silky smooth."

What about all those wonderful antibacterial, breathable properties bamboo fabric was said to have? Greenwashing. "Even when bamboo is the 'plant source' used to create rayon, no traits of the original plant are left in the finished product," the FTC reported. I'll won't repeat the "we've been bamboozled" cliché. But it gives me a good idea for a t-shirt.

Photo: Handspun bamboo thread that has been carbonized for color. Credit: Heather Kennedy.

Wide Angle: Tsunami-Proof Buildings Gaining Ground

October 20, 2009

Geotechnical engineer Yumei Wang, who works for Oregon state, warns that it's only a matter of time before a tsunami hits the Pacific Northwest. Yikes. I mean, YIKES!!! Fortunately for the vulnerable populace, Wang has a plan.

She proposes that low-lying communities collaborate to construct what she calls "tsunami evacuation buildings." I think "post-wave outposts" sounds better, but that's just me. Such a building would be made from reinforced concrete and have an 18-foot first floor, wide columns connected to a deep pile foundation, a wide external stairwell, and seawalls along the exterior to dissipate waves. An open plan would allow the building to have other daily uses.

As an engineer with the Oregon Department of Geology and Mineral Industries in Portland, Wang is meeting with officials in Cannon Beach about potentially constructing the nation's first tsunami evacuation building (PDF) by retrofitting the town hall. While the estimated cost is between $1 million and $2 million, doing nothing would be worse since around 100,000 people live in the state's risk areas. Maybe they could even use green concrete. A retrofit definitely beats my idea: water wings as fashionable accessories.

Photo: Walk this way: Shirahama tsunami evacuation structure in Japan. Credit: Nobuo Shuto.

German Solar Cube House Wins DC Decathlon

October 16, 2009

On the final, rainy, day of judging at the fourth Solar Decathlon in Washington, DC, I found myself busting a move with the German team in their solar house. Maybe that was what pushed them over the top.

Today, the U.S. Department of Energy announced that Team Germany from Technische Universität Darmstadt had won the competition, coming away with glory and bragging rights. For the uninitiated, the Solar Decathlon is a DOE-sponsored event where college teams from around the world design and build family homes on the National Mall that run solely on solar power.

When the judges aren't evaluating the homes in 10 different weighted categories, the public can traipse through for inspiration. Despite the cold and steady rain yesterday, the German house was packed with visitors drawn to its futuristic cube shape. The team had cleverly used photovoltaics on all sides for maximum power. Team member Patrick Tauchert told me that one of their strategies was to take features that worked and push them as far as they could go. Even on a gloomy day they still had an impressive surplus, but maintaining a comfortable temperature was key so the whole team danced in unison to generate more heat. I'm pretty sure they're still dancing, but this time in celebration. 

Photo: Visitors flock to the decathlon, and to the German house (far right). Credit: Stefano Paltera/U.S. Department of Energy Solar Decathlon.

Raise the Roof: Tiles Change With the Seasons

October 14, 2009

Looking at a sea of black-topped roofs during a city summer is maddening. They should be painted white! No wonder we're scorching! Then winter rolls around. Now scientists bring us roof tiles that go both ways.

A team of seven recent MIT grads from the Department of Materials Science and Engineering calling themselves Thermeleon created temperature-sensitive tiles made from commercial polymer sandwiched between flexible plastic layers. Cold causes the polymer to dissolve, exposing a dark layer at the back of the tile while heat makes it form droplets that coalesce into a white surface.

The team is still doing testing on the tiles to determine just how much energy savings they produce, and how durable they'll be. Plus they're experimenting with a paint form. They estimate the tiles could cost about the same as traditional roofing materials. While it's hard to compete with a green roof--in part because it seems like fun to hang out on one--Thermeleon tiles might morph into a viable alternative.

Photo: MIT grad Nick Orf turns up the heat on a roof tile. Credit: Patrick Gillooly.