Friday, October 9, 2009
A spoonful of herbicide helps the sugar break down in a most delightful way. Researchers at Brigham Young University have developed a fuel cell – basically a battery with a gas tank – that harvests electricity from glucose and other sugars known as carbohydrates.
The human body’s preferred energy source could someday power our gadgets, cars or homes.
“Carbohydrates are very energy rich,” said BYU chemistry professor Gerald Watt. “What we needed was a catalyst that would extract the electrons from glucose and transfer them to an electrode.”
The surprising solution turned out to be a common weed killer, as reported by Watt and his colleagues in the October issue of the Journal of The Electrochemical Society. Watt shares his wonderfully appropriate last name with his great-great-uncle James Watt, the inventor of the steam engine.
The effectiveness of this cheap and abundant herbicide is a boon to carbohydrate-based fuel cells. By contrast, hydrogen-based fuel cells like those developed by General Motors require costly platinum as a catalyst.
The next step for the BYU team is to ramp up the power through design improvements.
The study reported experiments that yielded a 29 percent conversion rate, or the transfer of 7 of the 24 available electrons per glucose molecule.
“We showed you can get a lot more out of glucose than other people have done before,” said Dean Wheeler, lead faculty author of the paper and a chemical engineering professor in BYU’s Fulton College of Engineering and Technology. “Now we’re trying to get the power density higher so the technology will be more commercially attractive.”
Since they wrote the paper, the researchers’ prototype has achieved a doubling of power performance. And they’re pursuing an even stronger sugar high.
(Photo: Brigham Young University)
Brigham Young University
The research, which also details new fossil specimens indicating the presence of a new species of giant varanid found on the island of Timor, is published September 30 in the open-access, peer-reviewed journal PLoS ONE.
Author Scott Hocknull, Senior Curator of Geosciences at the Queensland Museum, said Australia is a hub for lizard evolution.
"The fossil record shows that over the last four million years Australia has been home to the world's largest lizards, including a five metre giant called Megalania (Varanus prisca)," Mr Hocknull said.
"Now we can say Australia was also the birthplace of the three-metre Komodo dragon (Varanus komodoensis), dispelling the long-held scientific hypothesis that it evolved from a smaller ancestor in isolation on the Indonesian islands.
"Over the past three years, we've unearthed numerous fossils from eastern Australia dated from 300,000 years ago to approximately four million years ago that we now know to be the Komodo dragon.
"When we compared these fossils to the bones of present-day Komodo dragons, they were identical," he said.
The varanids are a group of giant monitor lizards, which are the world's largest terrestrial lizards and which were ubiquitous in Australasia for over 3.8 million years, having evolved alongside large-bodied, mammalian carnivores, such as Thylacoleo, the 'marsupial lion'. Growing to 2-3 metres in length and weighing around 70 kilos, the Komodo dragon is the last of the truly giant monitor lizards. New fossil discoveries show that the ancestor of the Komodo dragon evolved on mainland Australia, around 3-4 million years ago and then dispersed west to Indonesia. Historically, Australia was home to many other giant monitor lizards, including Megalania (Varanus prisca)—once the world's largest terrestrial lizard but which died out around 40,000 years ago.
"This research also confirms that both giant lizards, Megalania (Varanus priscus) and the Komodo dragon (Varanus komodoensis) existed in Australia at the same time," Mr Hocknull said.
Scott Hocknull and his international team have compared fossil evidence of Komodo dragons and other giant varanids in order to reconstruct the palaeobiogeography of the world's largest land-based lizards. The researchers hope this will have implications for the conservation of the Komodo dragon, which is now found on just a few isolated islands in eastern Indonesia, between Java and Australia, and vulnerable to extinction, probably due to habitat loss and persecution by modern humans over the last few millennia.
It was previously thought that the Komodo Dragon evolved its large size as a response to insular island processes, lack of carnivore competition, or as a specialist hunter of pygmy elephants called Stegodon. However, Hocknull and colleagues report that the ancestor of the Komodo dragon most likely evolved in Australia and spread westward, reaching the Indonesian island of Flores by 900,000 years ago. Comparisons between fossils and living Komodo dragons on Flores show that the lizard's body size has remained relatively stable since then—a period marked by the extinction of the island's megafauna, the arrival of early hominids by 880,000 years ago, and the arrival of modern humans by 10,000 years ago. Within the last 2,000 years, however, their populations have contracted severely.
Further support for the theory that the giant varanids dispersed to Indonesia from Australia comes from the island of Timor, located between Australia and Flores. Three fossil specimens from Timor represent a new (unnamed) species of giant monitor lizard, which was larger than the Komodo dragon (although smaller than Megalania). More specimens of this new Timor-Australian giant lizard are needed before the species can be formally described.
Australian researchers have discovered a huge number of new species of invertebrate animals living in underground water, caves and "micro-caverns" amid the harsh conditions of the Australian outback.
A national team of 18 researchers has discovered 850 new species of invertebrates, which include various insects, small crustaceans, spiders, worms and many others.
The team – led by Professor Andy Austin (University of Adelaide), Dr Steve Cooper (South Australian Museum) and Dr Bill Humphreys (Western Australian Museum) – has conducted a comprehensive four-year survey of underground water, caves and micro-caverns across arid and semi-arid Australia.
"What we've found is that you don't have to go searching in the depths of the ocean to discover new species of invertebrate animals – you just have to look in your own 'back yard'," says Professor Austin from the Australian Center for Evolutionary Biology & Biodiversity at the University of Adelaide.
"Our research has revealed whole communities of invertebrate animals that were previously unknown just a few years ago. What we have discovered is a completely new component to Australia's biodiversity. It is a huge discovery and it is only about one fifth of the number of new species we believe exist underground in the Australian outback."
Only half of the species discovered have so far been named. Generically, the animals found in underground water are known as "stygofauna" and those from caves and micro-caverns are known as "troglofauna".
Professor Austin says the team has a theory as to why so many new species have been hidden away underground and in caves.
"Essentially what we are seeing is the result of past climate change. Central and southern Australia was a much wetter place 15 million years ago when there was a flourishing diversity of invertebrate fauna living on the surface. But the continent became drier, a process that last until about 1-2 million years ago, resulting in our current arid environment. Species took refuge in isolated favorable habitats, such as in underground waters and micro-caverns, where they survived and evolved in isolation from each other.
"Discovery of this 'new' biodiversity, although exciting scientifically, also poses a number of challenges for conservation in that many of these species are found in areas that are potentially impacted by mining and pastoral activities," he says.
(Photo: U. Adelaide)
University of Adelaide