Straw as Building Material for Future

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A modern take on straw-bale construction may well be the grand design of the future if results coming out of the University of Bath are accepted by the construction industry. Think of a straw-bale house and you might imagine a tumbledown shack that leaks, creaks, slumps and smells somewhat of the farmyard. But step into Bale-Haus, a startlingly contemporary looking prototype home that has been built on the Bath Campus and there’s nary a wisp of straw to be seen. Instead, you are in a hallway of an upside down house with two bedrooms and a bathroom on the ground floor and an airy open plan living area upstairs. It feels like a little piece of Scandinavia has just arrived in Somerset, southwest England. The straw bales are all packed tightly inside a series of prefabricated rectangular wooden wall frames, which are then lime rendered, dried and finally slotted together like giant Lego pieces called ModCell panels.

People perceive straw houses as being a bit hippy and not particularly durable. Add to that the problems of getting mortgage – very few lenders will consider straw-bale construction. The benefits of straw, points out Professor Peter Walker, director of the University of Bath’s BRE Centre for Innovative Construction Materials, are that “it’s cheap, widely available and a good insulator. It’s been used in buildings houses for hundreds of years”.

The stack that remains after grain has been harvested – straw also helpfully soaks up carbon from the atmosphere and locks it in, so long as it is not allowed to decompose. For the building industry, which currently depends on materials with very high embedded energy costs -  concrete and brick are expensive in carbon terms both to make and to transport – straw could therefore offer a welcome solution to housing’s greenhouse gas emission.

The straw-bale house won’t get sopping wet in a thunderstorm or go up in a whoosh of flames if you knock over a candle. The results now being published by Walker and his research partner, Dr Katharine Beadle, who have spent the past 18 months testing the BaleHaus against an exhaustive list of risk factors that could rot it, burn it or blow it down, so far seem to be reassuring.

Beadle with his team took a ModCell unit to a test laboratory and tried to reduce it to ashes by strapping it to a fiery furnace and raising the temperature to over 1,000 degree Celsius. “It’s standard test to replicate a fire in a building.” explains Walker. “It means you know that a house will at least retain its structural integrity for half an hour, which gives people a chance to get out”. “It took an hour and a half of being in direct contact with the flames”, says Beadle, before the lime render began to drop off, “and then the straw did start to burn back, but because it’s so compacted it suffered more charring then actual disintegration.”

When it come to blowing the house down – hydraulic jacks were placed against the walls to replicate wind forces pushing against the bales – the ModCell panels moved a few millimeters, but stayed within the tolerances allowed for by the computer modeling carried out prior to its construction. That says Walker, could be very good news for the price of the eventual ModCell building system. “It means the house is stiffer than it needs to be.” The approximate cost of the current modular building system for this design is £132,000 from above the concrete slab. “Cost is a challenge to the introduction of this technology but as a prototype house I think it stacks up well,” said Walker. “The aspiration is that it should be cost competitive with more savings coming through reduced heating bills.”

To replicate the heat given off by humans and appliances arrays of incandescent light bulbs on timers blaze in every room at pre-programmed times of day “to see how much heat escapes, and what level of heating would be needed at different times of the year,” explains Beadle.

“That environmental modeling will give us all the numbers about the energy the house is predicted to use. And if we are predicting how it will operate in given climate change, we can then put in those variables.”

Sensors embedded within each wall panel constantly monitor the degree of moisture absorbed and then released back through the breathable lime render into the sir outside by the panels. And on the air tightness test that was carried out, BaleHaus came in way under the building regulations threshold, and did considerably better than the far lowest “best practice” standard.

- The Guardian

Why don’t you walk and generate some electricity

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Juicing up the portable electric devices on the go using energy emitted from human bodies is a dream long conceived by researchers and technology developers. This might now be near possible with this latest development by researchers at the University of Wisconsin in Madison.

Using reverse electrowetting technology that converts the energy generated by moving liquid into electricity the system will be embedded in footware to generate about 20 watts of usable electricity, using heat lost from the body during walks. This can charge up small portable devices and in the future, might generate enough juice to power up those hefty energy drinking mobile phones too.

Other uses of dental floss

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There are so many ways to use dental floss than just keeping your teeth and gums healthy. Here are few of the many alternative uses of dental floss:

  1. Hang time: Use dental floss to hang pictures. In fact, you can use it to hang just about any small object in need of string or wire.
  2. Sew neat: If you have ever had a coat button that keeps coming off, try dental floss instead of thread the next time you sew it on.
  3. Cookie saver: Crumbling cookies got you down? Slide some floss underneath your baked goods to easily lift them off the baking tray.
  4. It’s a wrap: Use dental floss, instead of twine, to securely tie packages for mailing.
  5. Gone fishing: If you happen to break your fishing line, dental floss makes a sturdy replacement.

Oil spill responsible for corals death

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“It reminds me of going to a family funeral,” said Charles Fisher, a biology professor at Penn State University, and chief scientist on a recent mission to study the impact of the Gulf oil spill on coral in the area.

Just like seeing extended family, “It’s always fun to go into the deep sea, and we saw a lot of life” he said. “But, on the other hand the reason you’re there is not a happy reason. Some corals have been severely slimmed. Some are dead or dying.”

The Woods Hole Oceanographic Institution in Woods Hole, Mass, led a nine-day mission this month to study the effects of the oil spill on life at the bottom of the sea. A team of scientists set out on a research vessel, spending just over a week in the middle of the Gulf of Mexico.

Equipped with both an autonomous submarine called Sentry, as well as a submersible called Alvin, the scientists photographed, mapped and collected samples from the Gulf nearly 24 hours a day. They completed six dives on Alvin, and set up a camera near the site of a dying coral reef, which will snap photos every hour for the next two months monitoring the coral’s heath.

The expedition follows on the heels of an earlier cruise in which many of the same scientists found dozens of coral species seven miles from the spill site that appeared to be dead or dying. The scientists revisited that same site, looked for other coral reefs, and took photos and samples from both the sick coral as well as another colony of reefs that appeared healthy.

“I probably had the happiest experience on the cruise,” said Chris German, chief scientist for deep submergence at Woods Hole. “I got to see the healthy coral.” More disheartening were the damaged and dying corals coated with a brown gooey substance. While German said the team was refraining from making any conclusions about the source of the brown goo before the analysis was complete, he said, “it doesn’t look like it is part of the natural system.”

The coral were “covered in brown goop that we haven’t seen anywhere else,” German said, describing the site as a “smoking gun” that may be representative of other impacted coral communities.

German said that the coral coated in brown goop was about seven miles southwest of the spill site. Based on the ocean currents and the dynamics of the gushing oil, scientists were able to predict where the oil plume was likely to spread. The dying coral was found in that area, while the healthy coral about 15 miles southeast of where the rig exploded was likely out of range of the plume, German said.