Science News

Researchers Reveal

Process of Making Ribs

ScienceDaily (Apr. 29, 2010) — Like all vertebrates, snakes, mice and humans have in common a skeleton made of segments, the vertebrae. But a snake has between 200-400 ribs extending from all vertebrae, from the neck to the tail-end, whereas mice have only 13 pairs of ribs, and humans have 12 pairs, in both cases making up the ribcage.


In the latest issue of Developmental Cell, researchers from the Instituto Gulbenkian de Ciência, in Portugal, reveal that, contrary to what was thought, making ribs is not the default state for vertebrates, but is actually an active process of balancing the activities of a remarkable class of genes — the Hox genes.

It was thought that the rib less region of the mouse embryo was the result of a rib-inhibiting programme, driven by Hox10 genes. Indeed, previous studies, in which Hox10 genes were inactivated in the embryo, generated mice with extra ribs. However, by forcing another class of Hox genes (Hox6) to be activated in future rib-less regions of the mouse embryo, Moises Mallo and his team bred mice that also have extra ribs, both in the neck area, and from just after the rib cage, all the way down to the tail, resembling a snake-like skeleton.

“It was an extraordinary, and clear-cut result,” says Mallo, “suggesting that these two groups of Hox genes balance each other out: one actively promotes rib formation to produce the thoracic region, while the other blocks this activity in the lumbar region. Our results have unveiled this balance.”

The researchers went on to unpick the genes involved in this process, and came up with yet another surprising finding: that the whole process relies on first hitting so-called muscle genes in the embryo, which then provide signals to switch on the ‘rib’ genes to make both ribs and muscle, in a coordinated process.

According to Mallo, “Our findings reveal a more complicated process than we would have imagined, but one that makes perfect sense, from a functional and evolutionary point of view: it is no good to make ribs without muscle, so, in the embryo, the production of both ribs and their associated muscles is under the control of a single and coordinated mechanism.”

Sourced and published by Henry Sapiecha 29th April 2010

Rust Removal Using – Soda Pop?

When I was about 12 years old and just getting interested in engines I heard my uncle swear that he got a stuck piston out of a motorcycle he had by using bottle of Coke. It had set out in the yard all winter and had rusted up inside. But we all know pop is sticky, water based and wouldn’t it make a worse mess? After all, Mom always said “don’t spill your pop, it will make everything sticky”.
As I grew up and got interested in cars and motorcycles myself I started to hear of other such “urban legends” and decided, hey, maybe there is something to this. The people that said it worked were quite insistant, and there sure was no proof that it did NOT work. So I decided to investigate. (amazing what little it takes to entertain me)

So here is what I’ve found – many carbonated beverages will remove rust. This is because the gas used, carbon dioxide when mixed with water, makes carbonic acid. To make rust, the iron oxidizes – it combines with oxygen. This is why rust is also called iron oxide. The carbonic acid reverses this reaction – this reversal is called “reduction.” Here’s a better reason – take a look at your Coke can – it has phosphoric acid as an ingredient. Phosphoric acid is the basis of Naval Jelly, a commercial product used for rust removal. Phosphoric acid dissolves iron oxide very quickly while etching metallic iron very slowly so you can leave metal in phosphoric acid with little damage.

The downside is that all acids contribute some hydrogen to the metal structure, weakening the steel by hydrogen embrittlement – so always use only as much time as is absolutely necessary to remove the rust. An advantage of phosphoric acid is that it leaves a fine protective coating of iron phosphate. Because this coating is not thick or durable some protection is still required. Years ago supposedly Volkswagon use a process of phosphating metal prior to painting as it provided a chemical protection against rust under the paint layer.
So, spilling your Coke into your old engine wouldn’t really be a bad thing if you were trying to remove some rust.

Sourced and published by Henry Sapiecha 27th April 2010

Microbes galore in seas; “spaghetti” mats Pacific

HUGE MATS OF TOXIC BACTERIA ON SEA BEDS


By Alister Doyle, Environment CorrespondentPosted 2010/04/18 at 1:09 pm EDT

OSLO, Apr. 18, 2010 (Reuters) — The ocean depths are home to myriad species of microbes, mostly hard to see but including spaghetti-like bacteria that form whitish mats the size of Greece on the floor of the Pacific, scientists said on Sunday.


The survey, part of a 10-year Census of Marine Life, turned up hosts of unknown microbes, tiny zooplankton, crustaceans, worms, burrowers and larvae, some of them looking like extras in a science fiction movie and underpinning all life in the seas.

“In no other realm of ocean life has the magnitude of Census discovery been as extensive as in the world of microbes,” said Mitch Sogin of the Marine Biological Laboratory in Woods Hole, Massachusetts, head of the marine microbe census.

The census estimated there were a mind-boggling “nonillion” — or 1,000,000,000,000,000,000,000,000,000,000 (30 zeroes) — individual microbial cells in the oceans, weighing as much as 240 billion African elephants, the biggest land animal.

Getting a better idea of microbes, the “hidden majority” making up 50 to 90 percent of biomass in the seas, will give a benchmark for understanding future shifts in the oceans, perhaps linked to climate change or pollution.

Among the biggest masses of life on the planet are carpets on the seabed formed by giant multi-cellular bacteria that look like thin strands of spaghetti. They feed on hydrogen sulphide in oxygen-starved waters in a band off Peru and Chile.

“Fishermen sometimes can’t lift nets from the bottom because they have more bacteria than shrimp,” Victor Gallardo, vice chair of the Census Scientific Steering Committee, told Reuters. “We’ve measured them up to a kilo (2.2 lbs) per square meter.”

GHOSTLY MATS

The census said they carpeted an area the size of Greece — about 130,000 sq km (50,000 sq miles) or the size of the U.S. state of Alabama. Toxic to humans, the bacteria are food for shrimp or worms and so underpin rich Pacific fish stocks.

The bacteria had also been found in oxygen-poor waters off Panama, Ecuador, Namibia and Mexico as well as in “dead zones” under some salmon farms. They were similar to ecosystems on earth that thrived from 2.5 billion to 650 million years ago.

Overall in the oceans, up to a billion microbe species may await identification under the Census, an international 10-year project due for completion in October 2010.

Tiny life was found everywhere, including at thermal vents with temperatures at 150 Celsius (300F) or in rocks 1,626 meters (5,335 ft) below the sea floor. Many creatures lack names or are hard to pronounce like loriciferans, polychaetes or copepods.

One major finding was that rare microbes are often found in samples where they can be outnumbered 10,000 to one by more common species. Isolated microbes may be lying in wait for a change in conditions that could bring a population boom.

Ann Bucklin, head of the Census of Marine Zooplankton that include tiny transparent crustaceans or jellyfish, said the seas were barely studied even by the census.

“Seventy percent of the oceans are deeper than 1,000 meters,” Bucklin, of the University of Connecticut, told Reuters. “The deep layer is the source of the hidden diversity.”

Paul Snelgrove, of Memorial University in Canada, said one sample in the South Atlantic in an area the size of a small bathroom — 5.4 square meters — turned up 700 species of copepod, a type of crustacean, 99 percent of them unfamiliar.

Just finding Latin names for each find will be hard. Scientists had rejected the idea of raising funds by letting people pay to have a marine “bug” named after them.

Sourced and published by Henry Sapiecha 21st April 2010

Chinese Pigs ‘Direct Descendants’ of

First Domesticated Breeds

ScienceDaily (Apr. 20, 2010) — Modern-day Chinese pigs are directly descended from ancient pigs which were the first to be domesticated in the region 10,000 years ago, a new archaeological and genetic study has revealed.


An international team of researchers, led by Durham University (UK) and the China Agricultural University, in Beijing, say their findings suggest a difference between patterns of early domestication and movement of pigs in Europe and parts of East Asia.

The research, published April 19 in the Proceedings of the National Academy of Sciences USA, looked at the DNA sequences of more than 1,500 modern and 18 ancient pigs.

Lead author Dr Greger Larson, in the Department of Archaeology, at Durham University, said: “Previous studies of European domestic pigs demonstrated that the first pigs in Europe were imported from the Near East. Those first populations were then completely replaced by pigs descended from European wild boar.

“However, despite the occurrence of genetically distinct populations of wild boar throughout modern China, these populations have not been incorporated into domestic stocks.

“The earliest known Chinese domestic pigs have a direct connection with modern Chinese breeds, suggesting a long, unbroken history of pigs and people in this part of East Asia.”

The finding is part of a wider research project into pig domestication and early human migration in East Asia.

The study also uncovered multiple centres of pig domestication and a complex picture of human migration across East Asia.

After pigs were incorporated into domestic stocks in Southeast Asia, the animals then migrated with people south and east to New Guinea, eventually reaching the remote Pacific, including Hawai’i, Tahiti, and Fiji, the researchers said.

The DNA analysis also found that wild boar were probably domesticated in many places including India and peninsular Southeast Asia several thousand years ago.

As current interpretations of archaeological records in these regions do not yet support these findings, the group has referred to them as “cryptic domestications.”

They suggest that additional archaeological digs and new analytical techniques may help to resolve the problem.

Dr Larson added: “Our evidence suggests an intriguingly complex pattern of local domestication and regional turnover and calls for a reappraisal of the archaeological record across South and East Asia.

“We may even find additional centres of pig domestication when we take a closer look at the picture in that part of the world.”

The research is part of an ongoing research project based at Durham University which aims to re-evaluate the archaeological evidence for pig domestication and husbandry and explore the role of animals in reconstructing ancient human migration, trade and exchange networks.

The DNA testing was carried out at the China Agricultural University and was analysed at Durham University and Uppsala University, Sweden.

The research was funded by the National Basic Research Programme of China and the National Key Technology R&D Programme of China.

Sourced and published by Henry Sapiecha 21st April 2010

High Carb Diet Linked to Prostate

Tumor Growth

ScienceDaily (Nov. 28, 2007) — A diet high in refined carbohydrates, like white rice or white bread, is associated with increased prostate tumor growth in mice.


Having too much insulin in the blood, a condition called hyperinsulinemia, is associated with poorer outcomes in patients with prostate cancer. Vasundara Venkateswaran, Ph.D., of Sunnybrook Health Sciences Centre in Toronto and colleagues investigated whether high insulin levels caused by eating a diet high in refined carbohydrates would lead to more rapid growth of prostate tumors in mice.

Forty mice were randomly assigned to either a high carbohydrate-high fat diet or a low carbohydrate-high fat one for nine weeks. The researchers measured the animals’ weight, tumor size, and insulin levels weekly. Mice on the high carbohydrate diet gained more weight, had faster growing tumors, and had higher insulin levels than mice on the low carbohydrate diet.

“Our results provide support for the concept that diets associated with a reduction in insulin level may have benefits for prostate cancer patients, particularly for the subset of patients who are hyperinsulinemic,” the authors write.

Sourced and published by Henry Sapiecha 19th April 2010

High-Altitude Metabolism Lets Mice

Stay Slim and Healthy

on a High-Fat Diet

ScienceDaily (Apr. 16, 2010) — Mice that are missing a protein involved in the response to low oxygen stay lean and healthy, even on a high-fat diet, a new study has found.


“They process fat differently,” said Randall Johnson, professor of biology at the University of California, San Diego, who directed the research, which is published in the April 15 issue of the journal Cell Metabolism. While their normal littermates gain weight, develop fatty livers and become resistant to insulin on a high fat diet, just like overweight humans do, the mutant mice suffered none of these ill effects.

The protein, an enzyme called FIH, plays a key role in the physiological response to low levels of oxygen and could be a new target for drugs to help people who struggle with weight gain. “The enzyme is easily inhibited by drugs,” Johnson said.

Because the protein influences a wide range of genes involved in development, the scientists were surprised that its deletion improved health.

“We expected them to die as embryos,” said Na Zhang, a graduate student in Johnson’s lab and lead author of the study. “Then we saw they can survive for a long time.”

“From the beginning I noticed that these mice are smaller, but not sick. These mice seem to be healthy,” Zhang said. The lean mice have a high metabolism, and a common check for insulin resistance, a symptom of diabetes, revealed a super sensitivity to insulin.

“We fed the mice with a very high fat diet — 60 percent fat — just to see how they would respond,” Zhang said. “Mutants can eat a lot, but they didn’t gain a lot of weight. They are less fatty around their middles compared with their littermates.”

Obese people develop a “fatty liver,” and so did the wild type littermates. The fat mice also developed high blood cholesterol with elevated levels of the “bad” type, LDL. In lean mutants, LDL increased much less.

“All of these observations support that the modified mice have better metabolic profiles,” Zhang said.

The genetic manipulations disabled the FIH gene entirely. “In every tissue, in every cell, the protein is gone,” Zhang said. But the scientists wanted to know what part of the mouse physiology was responsible for the changes, so they created new mice in which the FIH protein was deleted only in specific tissues: the nervous system or the liver.

Mice that were missing FIH only from their nervous system showed most of the same effects. “But if it was only deleted in the liver, then no.” Zhang said.

Though smaller, the mutant mice eat and drink 30 to 40 percent more than wild-type mice.

“Where do those calories go? To heat generation and an increased heart rate.” Johnson said. They also breathe heavily compared with normal mice, taking in 20 to 40% more air. “This deep breathing is like exercise for them.”

The FIH protein is part of a wide system that responds to low levels of oxygen. The mice behave as if they are breathing thin air. When people travel to higher altitudes, they breathe heavily for a few days, then adjust by producing more oxygen-carrying blood cells. “These mice never adjust to the apparent low oxygen,” Johnson said. “They stay in this acute phase of hypoxic response their whole lives.”

Sourced and published by Henry Sapiecha 19th April 2010

Natural Solar Collectors

On Butterfly Wings

Inspire More Powerful Solar Cells

ScienceDaily (Feb. 5, 2009) — The discovery that butterfly wings have scales that act as tiny solar collectors has led scientists in China and Japan to design a more efficient solar cell that could be used for powering homes, businesses, and other applications in the future.


In the study, Di Zhang and colleagues note that scientists are searching for new materials to improve light-harvesting in so-called dye-sensitized solar cells, also known as Grätzel cells for inventor Michael Grätzel. These cells have the highest light-conversion efficiencies among all solar cells — as high as 10 percent.

The researchers turned to the microscopic solar scales on butterfly wings in their search for improvements. Using natural butterfly wings as a mold or template, they made copies of the solar collectors and transferred those light-harvesting structures to Grätzel cells. Laboratory tests showed that the butterfly wing solar collector absorbed light more efficiently than conventional dye-sensitized cells. The fabrication process is simpler and faster than other methods, and could be used to manufacture other commercially valuable devices, the researchers say.

Sourced and published by Henry Sapiecha 15th April 2010

Cars of the Future:

Plastic Makes Perfect?

Automotive Engineers

Bend New Materials

into Futuristic Shapes

February 1, 2006 — New materials for car bodies may soon transform the auto industry. Auto engineers can mold these carbon-fiber-reinforced plastics into virtually any shape. The materials are both strong and light — increasing fuel efficiency and safety at the same time.


TROY, Mich.– Cars built entirely out of plastic could be the wave of the future, making metal a thing of the past when it comes to cars.

New, innovative cars made almost entirely of plastic are paving the way for what you may be driving in the future. Guan Chew,amechanical engineer at Porsche Engineering Services in Troy, Mich., says, “With plastics you can design cars which are very bold, and that gives you an advantage to sell nicer cars.”

Plastics have gained a lot of ground over traditional metals used in cars, making it possible to build almost an entire vehicle completely of non-metal material. Paul Ritchie, CEO and engineer at Porsche Engineering Services, says: “The Carrera GT is what we would refer to as a proving ground for one of our new materials. It’s made essentially from reinforced plastic.”

Mechanical engineers use a lightweight, high-strength aerospace material called carbon-fiber-reinforced plastic. It’s used in the doors, hoods, fenders, chasis and also in support frames for the engine and transmission.

“You can mold the plastics into very complicated shapes that maybe you can’t do in steel,” Chew says. Looks aren’t the only perks of plastic; plastics help cars lose weight to go farther on fuel.

New materials, like plastic, are usually tested on high-end vehicles first. Once the materials are proven to be more efficient and cost effective, they eventually filter down to affordable consumer vehicles.

BACKGROUND: Student designers at the College for Creative Studies are creating new plastic polymer materials as alternatives for automobile elements typically made of steel. The designs were part of a semester-long project sponsored by the American Plastics Council and the automotive division of the Society of Plastics Engineers.

ADVANTAGES: Among other advantages, plastics can significantly reduce the weight of a vehicle, improving fuel efficiency by reducing drag, and also cutting down on emissions. Because plastic can be more easily molded, components can be tailored for more comfortable human-ergonomic features, as well as more streamlined, aerodynamic shapes. Less material can be used than with steel components, and the durability of plastics results in a longer, more reliable vehicle lifetime.

ABOUT PLASTICS: Plastics are a type of polymer, a chemical substance made up of many very large, chain-shaped molecules. These molecules in turn form thousands of repeating units, much like the links in a chain. Different plastics are made by linking together different monomers into different length chains. Mixing polymers with various additives gives them many useful properties, which is why plastics are used so often in our everyday lives. Thermoplastics soften with heat and harden when cooled, such as polyvinylchloride (PVC) and Teflon. They are used in food packaging, milk and water bottles, electrical insulation, carpet fibers, and credit cards, among other applications. Thermosetting plastics harden with heat, such as epoxy and polyester. They can be found in mattresses, cushions, varnishes, glues, and coatings on electrical circuits.

MAKE YOUR OWN PLASTIC! Most plastics derive from oil (petroleum) but you can create the same kind of linked molecules with milk. (1) Pour 1/2 cup milk or heavy cream into a saucepan and heat to simmering over low to medium heat. (2) Stir in a few spoonfuls of vinegar or lemon juice; continue adding until mixture starts to gel. (3) Remove pan from heat and cool, then rinse the rubbery curds with water. The curds are plastic, formed by the chemical reaction between the casein in the milk and the acid in the vinegar or lemon juice.

Sourced and published by Henry Sapiecha 15th April 2010

Cars of Tomorrow

Automotive Engineers Team Up to

Improve Energy-Saving Technology

DAIMLER CHRYSLER HYBRID CAR

October 1, 2006 — Mechanical and electrical engineers at DaimlerChrysler, General Motors and BMW have jointly developed a hybrid-vehicle technology that shuts the internal combustion engine off when the vehicle stops. Meanwhile, engineers are working to replace the platinum in fuel cells with cheaper materials, which could lead to viable hydrogen cars.


AUBURN HILLS, Mich. — The high cost of hybrids has kept many people from going green, and a new Edmonds.com study shows that with the cost of gas — combined with tax credits — it only takes about three years to break even.

Now a new breed of hybrid is going to lessen that time even more. It’s the brainchild of not one car company but DaimlerChrysler, General Motors and BMW! They are all working together to create the car of tomorrow.

As gas prices go up, the pressure is on to create cars that use less.

“The hybrid system that we’re developing, we can apply to any vehicle that we have,” Glenn Denomme, a chief engineer of Hybrid Powertrain Programs at DaimlerChrysler in Auburn Hills, Michigan, tells DBIS.

It allows for increased performance compared to a conventional SUV and improves fuel economy by up to 25 percent. Denomme says, “You can still haul your cargo, but you can still be environmentally sound too.”

Today’s hybrid works best in stop-and-go traffic — tomorrow’s hybrid will give you better fuel economy, not only in the city, but on the highway. When the new hybrid is stopped, the advanced system shuts the internal combustion engine off, conserving fuel. When the car starts to move, electric power is used to conserve fuel, adding power from the engine as needed.

Speeding up even more, power from both the engine and electric motors are routed to the wheels for greater acceleration.

The new technology doesn’t stop there! A fuel cell car is 100-percent electric.

“It takes hydrogen and oxygen, combines it to form water, and at the same time produces electricity,” says Doanh Tran, an advanced vehicle engineer with DaimlerChrysler’s Fuel Cell Vehicles & Technologies.

Hydrogen can be produced from just about anything that has a hydrogen molecule, and the car has no emission out of the tailpipe except water vapor.

Right now, platinum is used for the fuel cell’s parts and is expensive, but materials engineers are working to find new metals. And as for mileage, it gets 56 miles per gallon, so a little can go a long way.

The fuel cell car won’t be for sale until around 2012. The new DaimlerChrysler hybrid will hit the market in 2008. It will cost more than a conventional car, but the price hasn’t been set yet.

BACKGROUND: The German-American consortium of BMW, DaimlerChrysler and General Motors are developing a new type of two-mode hybrid system for a wide range of cars, trucks and SUVs, starting with the 2008 Chevrolet Tahoe available in fall 2007. Current hybrids perform well in stop-and-go city driving, but don’t get as good mileage on the highway. The new hybrid version will get 25 percent better mileage in combined city and highway driving.

ADVANTAGES: Current hybrid engine systems have a single mode of operation, using a single gear set to split the engine’s power into two systems — routing it to drive the wheels or charge the battery — for both city and highway driving. Like other hybrids, the two-mode combines the power of a gasoline engine with that of electric motors, capturing energy from braking that would otherwise be lost and shutting off the engine at a stop. The battery alone can power the vehicle at low speeds. The new technology can operate much more efficiently at highway speeds with a greater boost from the electric motors, shutting down half the cylinders when not needed, thereby improving gas mileage. The components of the new two-mode system are also lighter and more compact, making them especially useful for reducing overall fuel consumption.

BATTERY BASICS: Whenever one type of matter converts into another, as in a chemical reaction, one form of energy also changes into another. A battery has two ends, called terminals, one with a negative charge, and one with a positive charge. Electrons congregate on the negative terminal. Connect a wire between the two terminals, and the electrons will flow from the negative to the positive end as quickly as they can. Connecting the battery starts the flow of electrons, jumpstarting a series of chemical reactions inside the battery to create even more electrons.

HOW FUEL CELLS WORK: Just like batteries, a fuel cell is a device that uses chemical reactions to convert hydrogen and oxygen into water, producing electricity in the process. A battery eventually goes dead when all the chemicals are used up, but in a fuel cell, there is a constant flow of chemicals into the cell. The voltage produced by fuel cells can be used to power lights, electrical appliances, and laptops, as well as cars and trucks. Fuel cells are light, more efficient than internal combustion engines, and don’t produce damaging emissions. They are currently expensive to manufacture, however.

Sourced and published by Henry Sapiecha 14th April 2010

Viruses Harnessed to Split Water

ScienceDaily (Apr. 12, 2010) — A team of MIT researchers has found a novel way to mimic the process by which plants use the power of sunlight to split water and make chemical fuel to power their growth. In this case, the team used a modified virus as a kind of biological scaffold that can assemble the nanoscale components needed to split a water molecule into hydrogen and oxygen atoms.


Splitting water is one way to solve the basic problem of solar energy: It’s only available when the sun shines. By using sunlight to make hydrogen from water, the hydrogen can then be stored and used at any time to generate electricity using a fuel cell, or to make liquid fuels (or be used directly) for cars and trucks.

Other researchers have made systems that use electricity, which can be provided by solar panels, to split water molecules, but the new biologically based system skips the intermediate steps and uses sunlight to power the reaction directly. The advance is described in a paper published on April 11 in Nature Nanotechnology.

The team, led by Angela Belcher, the Germeshausen Professor of Materials Science and Engineering and Biological Engineering, engineered a common, harmless bacterial virus called M13 so that it would attract and bind with molecules of a catalyst (the team used iridium oxide) and a biological pigment (zinc porphyrins). The viruses became wire-like devices that could very efficiently split the oxygen from water molecules.

Over time, however, the virus-wires would clump together and lose their effectiveness, so the researchers added an extra step: encapsulating them in a microgel matrix, so they maintained their uniform arrangement and kept their stability and efficiency.

While hydrogen obtained from water is the gas that would be used as a fuel, the splitting of oxygen from water is the more technically challenging “half-reaction” in the process, Belcher explains, so her team focused on this part. Plants and cyanobacteria (also called blue-green algae), she says, “have evolved highly organized photosynthetic systems for the efficient oxidation of water.” Other researchers have tried to use the photosynthetic parts of plants directly for harnessing sunlight, but these materials can have structural stability issues.

Belcher decided that instead of borrowing plants’ components, she would borrow their methods. In plant cells, natural pigments are used to absorb sunlight, while catalysts then promote the water-splitting reaction. That’s the process Belcher and her team, including doctoral student Yoon Sung Nam, the lead author of the new paper, decided to imitate.

In the team’s system, the viruses simply act as a kind of scaffolding, causing the pigments and catalysts to line up with the right kind of spacing to trigger the water-splitting reaction. The role of the pigments is “to act as an antenna to capture the light,” Belcher explains, “and then transfer the energy down the length of the virus, like a wire. The virus is a very efficient harvester of light, with these porphyrins attached.

“We use components people have used before,” she adds, “but we use biology to organize them for us, so you get better efficiency.”

Using the virus to make the system assemble itself improves the efficiency of the oxygen production fourfold, Nam says. The researchers hope to find a similar biologically based system to perform the other half of the process, the production of hydrogen. Currently, the hydrogen atoms from the water get split into their component protons and electrons; a second part of the system, now being developed, would combine these back into hydrogen atoms and molecules. The team is also working to find a more commonplace, less-expensive material for the catalyst, to replace the relatively rare and costly iridium used in this proof-of-concept study.

Thomas Mallouk, the DuPont Professor of Materials Chemistry and Physics at Pennsylvania State University, who was not involved in this work, says, “This is an extremely clever piece of work that addresses one of the most difficult problems in artificial photosynthesis, namely, the nanoscale organization of the components in order to control electron transfer rates.”

He adds: “There is a daunting combination of problems to be solved before this or any other artificial photosynthetic system could actually be useful for energy conversion.” To be cost-competitive with other approaches to solar power, he says, the system would need to be at least 10 times more efficient than natural photosynthesis, be able to repeat the reaction a billion times, and use less expensive materials. “This is unlikely to happen in the near future,” he says. “Nevertheless, the design idea illustrated in this paper could ultimately help with an important piece of the puzzle.”

Belcher will not even speculate about how long it might take to develop this into a commercial product, but she says that within two years she expects to have a prototype device that can carry out the whole process of splitting water into oxygen and hydrogen, using a self-sustaining and durable system.

Funding was provided by he Italian energy company Eni, through the MIT Energy Initiative (MITEI)

Sourced and published by Henry Sapiecha 14th April 2010