Heat-Sensitive Material Remembers Four Shapes

A substance called a polymer usually used to make fuel cells can “remember” up to four different shapes, and revert to each one at different temperatures, according to new research.

The polymer, or others like it, could be used in fields ranging from biomedical engineering to space exploration.

Perfluorosulphonic acid ionomer (PFSA) is what’s known as a shape memory polymer. A polymer is a substance made mostly of repeating identical or similar molecules.

The chemical structure of shape memory polymers allows them to “memorize” shapes under certain conditions of heat, magnetism or moisture. The next time they’re exposed to those conditions, the polymers revert back to the memorized shapes.

Shape-memory polymers have been commercially available for decades in the form of insulation for wiring and other industrial uses. Some have been tested for use in medical devices, such as stents that can shape-shift inside blood vessels to clear clots. NASA has considered shape-memory polymers as a way to fold up antennas for launch and then unfold them in space.

But until now, shape-memory polymers have only been able to hold two or three shapes total, and those shapes must be manipulated at certain temperatures.

A memory for shapes

But PFSA is different, said Tao Xie, a research scientist at General Motors and lead author of the new study.

It can hold up to four different shapes, including its original form. And as long as the gap between each temperature is large enough, each shape can be assigned to a temperature of the manufacturer’s choice.

Xie coaxed the shape-memory effect out of PFSA by heating thin films of the material, reshaping it to “fix” a shape, then cooling and reshaping again. When heated back up, the material reverted to each fixed shape, recalling up to four shapes total. So far, Xie has been able to twirl, elongate, and shorten strips of PFSA simply by changing the temperature.

PFSA has properties similar to other known shape-memory polymers, Patrick Mather, a professor of biomedical and chemical engineering at Syracuse University who was not involved in the research.

However, PFSA might not qualify under a strict definition of shape-memory polymers because the effect depends heavily on cycles of periodic, rather than continuous, heating, said Mather.

No special chemistry required

From a scientific standpoint, PFSA is “not a unique chemistry at all,” said Ken Gall, a materials scientist from Georgia Tech who was also uninvolved in Xie’s work.

But on a practical level, the fact that PFSA’s shape memory arises more from heating methods than from special chemistry could be important, he said, allowing manufacturers to use less expensive materials.

The study “shows you that the shape-memory property is a lot about the way you process and thermo-mechanically treat the material,” Gall told TechNewsDaily.

The next step, Xie said, is to look for shape-shifting materials that also have other useful properties, like biocompatibility for medical devices or ultra-violet radiation resistance for space equipment.

…

via Heat-Sensitive Material Remembers Four Shapes – Yahoo! News.

Cow gives birth to triplets

Caesar gave birth to calves Laura, Ben and Tom last week at North Park Farm in Landrake, Cornwall.

Her multiple delivery has been described as a miracle by Gary Bridgman, the farmer, although he disclosed that Caesar’s mother gave birth to twins last year.

Mr Bridgman said: “You don’t expect triplets. We had Caesar scanned but you never ask how many, so it’s a bit of a miracle to me.”

Cows do not normally have litters of calves and the chances of having triplets are 105,000 to one, with the odds of having same sex triplets are around 700,000 to one.

Experts from the Washington State University College of Veterinary Medicine have previously said a cow giving birth to triplets is a ‘statistical miracle.’

The average gestation period is about nine months – like humans – and a newborn calf will weigh between 40 to 50kg, but within a year they are usually the same size as their parents.

via Cow gives birth to triplets – Telegraph.

Possible Bigfoot Sighting In Leeds

Gossip is flying in the town of Leeds, but it’s not typical talk for small town Maine.

A local couple says Bigfoot is real and he’s living nearby. Monday morning a pair spotted a 7 foot tall, hairy man crossing the road near the Greene/Leeds town line. And they’re not alone. Over the last 25 years, There have been numerous Bigfoot sightings, leaving locals to believe there may be some truth to it. And it’s getting enough traction that a crypto zoologist visited to area to do his own investigation. In 2006 – there was a mysterious beast thought to live in Turner. It was later confirmed to just be a dog.

via WGME 13 Top Stories.

Mystery as scores of starlings fall out of the sky and lay dying… in a single front garden

It was like a grisly scene from a horror film.

On Sunday night, over a quiet Somerset house, scores of swooping starlings tumbled out of the sky and fell, dead, into a single front garden.

Covering an area 12ft across, more than 100 birds carpeted the garden, each with blood oozing from its beak and curled up claws.

Most had died, although some flapped lamely, clearly in pain until the RSPCA put them out of their misery.

Householder Julie Knight, 53, returned to her home in the quiet village of Coxley at 4.15pm to find the macabre scene, which has mystified experts.

An RSPCA expert said the cause of the deaths was ‘a mystery’, adding that the only plausible explanation was that the flock were being chased by a bird of prey and hit the ground as they changed direction

Julie, a nurse, said: ‘It was like something out of an horror film – like Hitchcock’s The Birds – it was absolutely terrifying.

‘The sky was raining starlings. One of my neighbours saw them. They seemed to just fall out of the sky. About 70 were dead straight away.

‘The only way to describe what they looked like is that they seemed to have had a fright and were petrified.

‘We called out the RSPCA and their animal welfare officer took a few away in cages and euthanised the rest.

‘There must have been over 100 birds in total. I’ve been a country girl all my life and I’ve never seen anything like it.’

Some of the bodies fell into the boughs of a tree, where a number of distressed surviving birds perched. Just six survived.

The uncanny scene in Mrs Knight’s garden mirrored that of an episode of cult Channel 5 hit Flash forward, in which a flock of crows falls out of the sky in Somalia.

Similar incidents of flocks of birds plummeting to earth have been reported all over the world, with pesticides and collisions sometimes being blamed.

Mrs Knight added: ‘I’m worried about what could have killed them because I have a young grandson and two cats that are often in my garden.

‘My only thoughts are that the birds, who are greedy in nature, had been eating crops sprayed with weedkiller and were poisoned – but it’s all very weird.’

Lloyd Scott, from the Royal Society for the Protection of Birds, said: ‘This is one of the oddest things I’ve ever heard about.

‘We’ve certainly never come across anything similar.’

He said it was unlikely that the birds had flown into each other in confusion.

‘Starlings have natural habits and behaviour, when flying around in a murmuration they relate each movement to the seven birds closest to them.

‘They are hardwired into doing this and on instinct they stay away from each other.’

He speculated that  the birds may have flown into a glass conservatory while taking part in their sky dance, but Mrs Knight insisted they had simply fallen out of the sky.

Post mortems on the starlings carried out today proved inconclusive.

They were all found to have physical injuries – with most suffering either broken wings or a shattered beak – but no underlying health problems or toxins which could explain their sudden deaths.  …

We know they did not strike power cables because they would have fallen directly beneath and there are none nearby.

via Mystery as scores of starlings fall out of the sky and lay dying… in a single front garden | Mail Online.

Ran into a cloaked UFO.

Old rocks drown dry Moon theory

Samples collected during Apollo missions suggest a wet interior, raising questions about lunar origins.

Larry Taylor always said he’d eat his shorts if water was ever found on the Moon. He never expected his own research to bring that pledge back to haunt him.

The petrologist, based at the University of Tennessee in Knoxville, was just 32 years old at the first Lunar and Planetary Science Conference in 1970, where his colleagues described their analyses of Moon rocks collected the previous year during the Apollo 11 mission. Taylor saw only pure metallic iron in the samples — a sign that there wasn’t any water around to rust the iron. This and other results that year led to the party line: the Moon is, and always was, bone dry.

Forty years on, at the same annual conference near Houston, Texas, Taylor and his colleagues announced that they have been wrong all along. At the meeting last week, three groups presented evidence that certain crystals in the volcanic rocks collected by Apollo astronauts contain as much as several thousand parts per million of water.

These findings go much deeper than the glimpses of frozen water on the Moon’s surface — discoveries that were made recently by India’s Chandrayaan-1 and NASA’s Lunar Reconnaissance Orbiter spacecraft (see Nature doi:10.1038/news.2009.931; 2009). The new studies of the Apollo samples provide hints of what lurks within the Moon.

The results suggest that the lunar interior has always held some water — challenging theorists to change their thinking about how the Moon formed during a fiery impact, and how the once-molten body cooled. The work also hints that comets have played a more important part in delivering water to the Moon than researchers had previously thought.

“This is revolutionary,” says Linda Elkins-Tanton, a lunar scientist at the Massachusetts Institute of Technology in Cambridge. As for Taylor, the one-time water sceptic has eaten his words — and more. In January, colleagues gave him a chocolate cake, iced white with pink polka dots to represent his boxer shorts.

via Old rocks drown dry Moon theory : Nature News.

DNA of extinct birds extracted from ancient eggshell

Researchers have found that eggshells of extinct bird species are a rich source of preserved DNA.

An international team isolated the delicate DNA molecules of species including the massive “elephant birds” of the genus Aepyorni.

The Proceedings of the Royal Society B research demonstrated the approach also on emu, ducks and the extinct moa.

The team says that the technique will enable researchers to learn more about ancient birds and why they died out.

“Researchers have tried unsuccessfully to isolate DNA from a fossil eggshell for years,” said Charlotte Oskam at Murdoch University in Western Australia, who authored the research.

“It just turned out that they were using a method designed for bone that was not suitable for a fossil eggshell.”

The team has obtained DNA from the shells of a variety of species, most notably the elephant bird Aepyornis , which at half a tonne was heaviest bird to have ever existed.

Aepyornis looked like an outsized ostrich, standing three metres tall; most of them died out 1,000 years ago.

Archaeologist Mike Parker Pearson at the University of Sheffield hopes that an analysis of the bird’s DNA will shed more light on why the bird became extinct.

The extinction coincided with humans arriving at Aepyornis‘s natural habitat in Madagascar.

The mystery, according to Professor Parker Pearson, is that there’s no evidence that the bird was hunted by humans. …

via BBC News – DNA of extinct birds extracted from ancient eggshell.