Writing in the June 4 edition of the journal Nature Communications, the scientists describe a new technique for producing low-cost, silicon-based batteries with potential applications for a wide range of electrical devices.

"Developing rechargeable lithium-ion batteries with high energy density and long cycle life is of critical importance to address the ever-increasing energy storage needs for portable electronics, electric vehicles and other technologies," said study co-author Zhenan Bao, a professor of chemical engineering at Stanford.

To find a practical, inexpensive material that increases the storage capacity of lithium-ion batteries, Bao and her Stanford colleagues turned to silicon - an abundant, environmentally benign element with promising electronic properties.

"We've been trying to develop silicon-based electrodes for high-capacity lithium-ion batteries for several years," said study co-author Yi Cui, an associate professor of materials science and engineering at Stanford. "Silicon has 10 times the charge storage capacity of carbon, the conventional material used in lithium-ion electrodes. The problem is that silicon expands and breaks."

Studies have shown that silicon particles can undergo a 400-percent volume expansion when combined with lithium. When the battery is charged or discharged, the bloated particles tend to fracture and lose electrical contact. To overcome these technical constraints, the Stanford team used a fabrication technique called in situ synthesis polymerization that coats the silicon nanoparticles within the conducting hydrogel.

This technique allowed the scientists to create a stable lithium-ion battery that retained a high storage capacity through 5,000 cycles of charging and discharging.

"We attribute the exceptional electrochemical stability of the battery to the unique nanoscale architecture of the silicon-composite electrode," Bao said.

Using a scanning electron microscope, the scientists discovered that the porous hydrogel matrix is riddled with empty spaces that allow the silicon nanoparticles to expand when lithium is inserted. This matrix also forms a three-dimensional network that creates an electronically conducting pathway during charging and discharging.

"It turns out that hydrogel has binding sites that latch onto silicon particles really well and at the same time provide channels for the fast transport of electrons and lithium ions," explained Cui, a principal investigator with the Stanford Institute for Materials and Energy Sciences at the SLAC National Accelerator Laboratory. "That makes a very powerful combination."

A simple mixture of hydrogel and silicon proved far less effective than the in situ synthesis polymerization technique.

"Making the hydrogel first and then mixing it with the silicon particles did not work well," Bao said. "It required an additional step that actually reduced the battery's performance. With our technique, each silicon nanoparticle is encapsulated within a conductive polymer surface coating and is connected to the hydrogel framework. That improves the battery's overall stability."

Hydrogel primarily consists of water, which can cause lithium-ion batteries to ignite - a potential problem that the research team had to address. "We utilized the three-dimensional network property of the hydrogel in the electrode, but in the final production phase, the water was removed," Bao said. "You don't want water inside a lithium-ion battery."

Although a number of technical issues remain, Cui is optimistic about potential commercial applications of the new technique to create electrodes made of silicon and other materials.

"The electrode fabrication process used in the study is compatible with existing battery manufacturing technology," he said.

"Silicon and hydrogel are also inexpensive and widely available. These factors could allow high-performance silicon-composite electrodes to be scaled up for manufacturing the next generation of lithium-ion batteries. It's a very simple approach that's led to a very powerful result."

Former Stanford postdoctoral scholars Hui Wu, now a faculty member at Tsinghua University-Beijing, and Guihua Yu, now a faculty member at the University of Texas-Austin, are co-lead authors of the study. Other authors are Stanford visiting scholar Lijia Pan and graduate students Nan Liu and Matthew McDowell.

]]> Wed, 12 JUN 2013 00:37:26 AEST Oak Ridge TN (SPX) Jun 07, 2013 - Scientists at the Department of Energy's Oak Ridge National Laboratory have designed and tested an all-solid lithium-sulfur battery with approximately four times the energy density of conventional lithium-ion technologies that powers electronics. The ORNL battery design, which uses abundant low-cost elemental sulfur, also addresses flammability concerns experienced by other chemistries.

"Our approach is a complete change from the current battery concept of two electrodes joined by a liquid electrolyte, which has been used over the last 150 to 200 years," said Chengdu Liang, lead author on the ORNL study published this week in Angewandte Chemie International Edition.

Scientists have been excited about the potential of lithium-sulfur batteries for decades, but long-lasting, large-scale versions for commercial applications have proven elusive.

Researchers were stuck with a catch-22 created by the battery's use of liquid electrolytes: On one hand, the liquid helped conduct ions through the battery by allowing lithium polysulfide compounds to dissolve. The downside, however, was that the same dissolution process caused the battery to prematurely break down.

The ORNL team overcame these barriers by first synthesizing a never-before-seen class of sulfur-rich materials that conduct ions as well as the lithium metal oxides conventionally used in the battery's cathode. Liang's team then combined the new sulfur-rich cathode and a lithium anode with a solid electrolyte material, also developed at ORNL, to create an energy-dense, all-solid battery.

"This game-changing shift from liquid to solid electrolytes eliminates the problem of sulfur dissolution and enables us to deliver on the promise of lithium-sulfur batteries," Liang said.

"Our battery design has real potential to reduce cost, increase energy density and improve safety compared with existing lithium-ion technologies."

The new ionically-conductive cathode enabled the ORNL battery to maintain a capacity of 1200 milliamp-hours (mAh) per gram after 300 charge-discharge cycles at 60 degrees Celsius.

For comparison, a traditional lithium-ion battery cathode has an average capacity between 140-170 mAh/g. Because lithium-sulfur batteries deliver about half the voltage of lithium-ion versions, this eight-fold increase in capacity demonstrated in the ORNL battery cathode translates into four times the gravimetric energy density of lithium-ion technologies, explained Liang.

The team's all-solid design also increases battery safety by eliminating flammable liquid electrolytes that can react with lithium metal. Chief among the ORNL battery's other advantages is its use of elemental sulfur, a plentiful industrial byproduct of petroleum processing.

"Sulfur is practically free," Liang said. "Not only does sulfur store much more energy than the transition metal compounds used in lithium-ion battery cathodes, but a lithium-sulfur device could help recycle a waste product into a useful technology."

Although the team's new battery is still in the demonstration stage, Liang and his colleagues hope to see their research move quickly from the laboratory into commercial applications. A patent on the team's design is pending.

"This project represents a synergy between basic science and applied research," Liang said. "We used fundamental research to understand a scientific phenomenon, identified the problem and then created the right material to solve that problem, which led to the success of a device with real-world applications."

The study is published as "Lithium Polysulfidophosphates: A Family of Lithium-Conducting Sulfur-Rich Compounds for Lithium-Sulfur Batteries,". In addition to Liang, coauthors are ORNL's Zhan Lin, Zengcai Liu, Wujun Fu and Nancy Dudney.

]]> Wed, 12 JUN 2013 00:37:26 AEST Cambridge, UK (SPX) Jun 11, 2013 - New battery-free, ultra-low power wireless sensor technology is being developed by UK-based TTP that will add connectivity and intelligence to everyday dumb objects such as medical implants, supermarket labels and engineering components. TTP believes it is through innovative energy harvesting techniques and low energy sensors that the Internet of Things will become a reality and billions of devices will communicate and interact with each other.

TTP is working on applications that range from sensors embedded in smart orthopaedic implants for remote monitoring, to battery-free sensors for measuring highly-stressed components in F1 engines and active supermarket labels that are always up to date with real-time data. And the same technology is being used for displaying the balance on Oyster-type pre-pay cards, controlling home energy systems or street lights and intelligent security or postal tags.

TTP expects many of these new sensors will connect to smartphones and tablets using ultra-low power Bluetooth technology or Near Field Communications (NFC) for close range transactions.

TTP has combined advanced ultra-low power electronic design with energy harvesting techniques such as making use of radio waves, vibration, heat and light and biological sources. It has also optimised the use of low-power wireless for communications and providing power through human tissue and metal in medical implants. Typically, these applications require the embedded sensing electronics to be fully encapsulated in Titanium and interrogated whilst deep within the body.

In Motorsport the technical challenges are quite different, although as with medical applications the demand for critical sensor data justifies the need for technological advancement. Battery-free sensors can be used to measure real-time parameters deep within mechanical systems such as engines, gearboxes and braking systems that experience extreme temperature and vibration.

"The technical challenges to deliver ultra-low power electronics and battery-free devices involve understanding the fundamental principles of electromagnetics and radio spectrum, propagation modelling and antenna design along with mechanical packaging, sensor integration and advanced system design," said Steve Taylor, senior consultant at TTP.

"As well as using innovative techniques to optimise the circuit designs we have developed new ultra-low power wireless protocols and a patent-pending technique for transmitting data through thick steel walls."

"With predictions that that the Internet of Things (IoT) will connect up to 50 billion devices, powering dumb objects and sensors to give them intelligence and communications is critical," says Dr Allan Carmichael, Business Development Manager at TTP.

"It is simply not feasible or environmentally desirable to use batteries, so harnessing and storing small amounts of energy is the only way to make the IoT work effectively. New battery-free and ultra-low power technologies that complement existing approaches such as NFC, Zigbee and Bluetooth Smart, will open up exciting new opportunities across a wide range of fields from health and smart energy to tracking, active displays and micro payments. The IoT vision is about connected devices improving our lives seamlessly without us knowing - and this will only work if we aren't worried about changing the batteries."

]]> Wed, 12 JUN 2013 00:37:26 AEST Garching, Germany (SPX) Jun 11, 2013 - Laptops could work longer and electric cars could drive farther if it were possible to further increase the capacity of their lithium-ion batteries. The electrode material has a decisive influence on a battery's capacity.

So far, the negative electrode typically consists of graphite, whose layers can store lithium atoms. Scientists at the Technische Universitaet Muenchen (TUM) have now developed a material made of boron and silicon that could smooth the way to systems with higher capacities.

Loading a lithium-ion battery produces lithium atoms that are taken up by the graphite layers of the negative electrode. However, the capacity of graphite is limited to one lithium atom per six carbon atoms.

Silicon could take up to ten times more lithium. But unfortunately, it strongly expands during this process - which leads to unsolved problems in battery applications.

Looking for an alternative to pure silicon, scientists at the Technische Universitaet Muenchen have now synthesized a novel framework structure consisting of boron and silicon, which could serve as electrode material.

Similar to the carbon atoms in diamond, the boron and silicon atoms in the novel lithium borosilicide (LiBSi2) are interconnected tetrahedrally. But unlike diamond they moreover form channels.

"Open structures with channels offer in principle the possibility to store and release lithium atoms," says Thomas Fassler, professor at the Institute of Inorganic Chemistry, Technische Universitaet Muenchen. "This is an important requirement for the application as anode material for lithium-ion batteries."

High-pressure synthesis
In the high-pressure laboratory of the Department of Chemistry and Biochemistry at Arizona State University, the scientists brought the starting materials lithium boride and silicon to reaction.

At a pressure of 100,000 atmospheres and temperatures around 900 degrees Celsius, the desired lithium silicide formed. "Intuition and extended experimental experience is necessary to find out the proper ratio of starting materials as well as the correct parameters," says Thomas Fassler.

Lithium borosilicide is stable to air and moisture and withstands temperatures up to 800 Celsius. Next, Thomas Fassler and his graduate student Michael Zeilinger want to examine more closely how many lithium atoms the material can take up and whether it expands during charging. Because of its crystal structure the material is also expected to be very hard, which would make it attractive as a diamond substitute as well.

Since the framework structure of the lithium borosilicide is unique, Fassler and Zeilinger could give a name to their new framework. In honor of their university, they chose the name "tum."

Cooperation partners of the project were the Department of Physics at University of Augsburg and the Department of Materials and Environmental Chemistry at Stockholm University. The work was funded by the TUM Graduate School, the German Chemical Industry Fund, the German Research Foundation, the Swedish Research Council and the National Science Foundation, USA.

Michael Zeilinger, Leo van Wullen, Daryn Benson, Verina F. Kranak, Sumit Konar, Thomas F. Fassler, and Ulrich Haussermann, LiBSi2: A Tetrahedral Semiconductor Framework from Boron and Silicon Atoms Bearing Lithium Atoms in the Channels, Angewandte Chemie International Edition 2013, 52, 5978-5982. DOI:10.1002/anie.201301540.

Michael Zeilinger, Daryn Benson, Ulrich Haussermann, Thomas F. Fassler: Single crystal growth and thermodynamic stability of Li17Si4, Chemistry of Materials 2013, 25, 1960-1967.

]]> Wed, 12 JUN 2013 00:37:26 AEST New York (AFP) June 10, 2013 - Shale-based resources increase the world's total potential oil reserves by 11 percent and natural gas by 47 percent, according to a US report released Monday.

In an initial assessment of shale oil resources and an update of shale gas reserves, the US Energy Information Agency said shale deposits could add 345 billion barrels of oil to global reserves, increasing the total to 3,357 billion barrels.

Shale gas adds 7,299 trillion cubic feet of natural gas, or 32 percent of the world total, the EIA report estimated.

The report seeks to quantify the potential global significance of the shale boom, after the exploitation of North American shale deposits transformed the US oil and gas industry.

It said an improvement in geologic data has allowed a better view of global resources. In addition to the United States, other countries with large shale resources include Russia, China, Argentina, Algeria and Libya.

However, the EIA cautioned that the estimates are "highly uncertain and will remain so until they are extensively tested with production wells."

The report also does not assess the economic viability of developing the resources. The cost of some wells internationally could be higher than in the US, potentially marking the "difference between a resource that is a market game changer and one that is economically irrelevant at current market prices."

So far, only the US and Canada produce shale energy in commercial quantities.

The report is an update of a 2011 EIA report on natural gas resources, boosting the global quantity of shale gas by 10.2 percent. The 2011 report did not estimate the global potential of shale oil.

Not all of the drilling data has led to higher estimates on resources.

EIA slashed the estimate for China to 1.1 trillion cubic feet of gas from 1.3 trillion cubic feet in 2011 after acquiring better data that revealed the size of key hydrocarbon fields and their total organic content.

China is estimated to have the world's greatest recoverable shale resources and the third-larges shale oil resources.

The report also cites recent drilling in Argentina, Mexico and Poland as shedding more light on resources. It does not assess prospective shale formations in some regions, such as the Middle East and the Caspian region.

The top six countries in terms of recoverable shale gas resources -- China, Argentina, Algeria, the US, Canada and Mexico -- account for more than 60 percent of the world's recoverable shale gas resources.

The top five countries in terms of recoverable shale oil -- Russia, the US, China, Argentina and Libya -- account for 63 percent of the world's total.

Because of both geology and "above-the-ground conditions," the report said, "the extent to which global technically recoverable shale resources will prove to be economically recoverable is not yet clear."

Key above-ground advantages in the US and Canada that may not apply in other countries include private ownership of subsurface rights "that provide a strong incentive for development," the report said.

EIA also cited the availability of many independent operators and supporting contractors with expertise and drilling rigs and preexisting gathering and pipeline infrastructure.

The report said the jump in US shale oil production played a role recently in keeping a lid on oil prices.

Longer term, the report said the effect of shale oil on oil prices will depend on the Organization of Petroleum Exporting Countries' "ability and willingness" to trim output. A retreat in prices could also boost oil consumption that "would tend to soften any long-term price-lowering effects of increased production."

The US boom has been enabled by the controversial drilling technique of hydraulic fracturing, which involves pumping fluids deep into rock to allow extraction.

Some countries, such as France and Bulgaria, have blocked fracking, while others, such as the Netherlands, are studying the issue.

]]> Wed, 12 JUN 2013 00:37:26 AEST New York (AFP) June 10, 2013 - Oil prices dropped Monday amid renewed concerns about China's appetite for crude oil after a batch of disappointing Chinese economic data.

New York's main contract, West Texas Intermediate for July, closed at $95.77 a barrel, down 26 cents from Friday.

In London trade, Brent North Sea crude for delivery in July fell 61 cents to settle at $103.95 a barrel.

China over the weekend published a slew of lukewarm economic indicators that sparked concerns about slower growth in the world's second-largest economy.

"Poor import data, retail sales that were not great, industrial production numbers that were a little bit lower than the market expected... it is getting the market thinking about how China growth will be doing over the next few months," said Bart Melek of TD Securities.

Prices also were under pressure after Friday's strong gain in New York, said Robert Yawger of Mizuho Securities USA.

"We run into trouble every time it gets to the $97-98 level," Yawger said, noting that the market has failed against that level three times since April.

"People are getting out of their position because they have previously not managed to get through that."

The decline in prices was limited by tensions between Sudan and South Sudan, Yawger added.

On Saturday Sudan President Omar al-Bashir shut the pipeline carrying South Sudanese crude for export, and on Sunday Sudan suspended nine security and economic pacts with South Sudan.

South Sudan produces about 350,000 barrels of oil per day but depends on Sudan's export infrastructure.

The two sides had not been able to agree on how much Juba would pay to use the pipeline.

In other oil market news, sit-in protests at Libyan oilfields have cost 250,000 barrels per day in lost production, Oil Minister Abdelbari al-Arussi said Monday.

Demonstrations have been held at the terminals at Al-Harriga in Tobruk and Zueitina in the east, and at the Al-Fil oilfield in Ubari in the south, Arussi said.

The minister gave no details of the reasons for the protests, but said that "these protests are affecting Libya's economy, which depends on oil and gas resources."

]]> Wed, 12 JUN 2013 00:37:26 AEST Barlad, Romania (AFP) June 07, 2013 - As Orthodox priest Vasile Laiu gazes over the picturesque hills of eastern Romania, he prays they will be spared the shale gas wells and drilling rigs dotting some US landscapes.

For months the 50-year-old cleric has been one of the most outspoken opponents to plans by US energy giant Chevron to drill for shale gas in this rural and impoverished region.

Clad in his black cassock, Father Laiu has joined thousands of locals in street protests against a project he says "threatens man, nature and future generations".

Growing up in an oil-producing region, he is not an enemy of the energy industry, he insists.

But like many he opposes the controversial drilling technique known as hydraulic fracturing or "fracking".

It involves injecting huge amounts of water, mixed with sand and chemicals, at high pressures to break up rock formations and release the gas.

Widely used in some US states such as Pennsylvania and Colorado, it has been banned in Vermont as well as in France and Bulgaria because of potential air and water pollution.

When the mayor of the eastern town of Barlad banned a rally against fracking last April, Laiu welcomed the protesters in his church.

"The Church does not interfere in politics but if the health or life of only one of my fellow men is put in danger, it is my duty as a priest to intervene," he told AFP in an interview.

Laiu, the top Orthodox priest in the Barlad region, has spent more than half of his life serving the villages. After the fall of communism in 1989 he watched his parishioners fight for jobs and farmers try to make ends meet in the new capitalist economy.

But since 2011, when Chevron obtained a 600,000-hectare (1.5 million-acre) concession to look for shale gas, the region has been caught in a new battle about its future.

Its promoters say shale gas extraction can create jobs, slash energy prices and provide a boost for the Barlad economy plagued by 10 percent unemployment, the highest rate in Romania.

Others dismiss the shale frenzy as a temporary fad that could cause lasting damage to the environment and public health. Thanks to the globalised world, the Oscar-nominated documentary "Gasland" and testimonies from American families about health problems they believe are linked to shale gas drilling have reached this far-flung corner of Romania.

A 2012 study by Duke University in the US state of North Carolina showed that drinking water wells are at risk of contamination from fracking because of underground pathways.

Father Laiu's main fears are over water. The area suffers from droughts, and fracking needs enormous amounts of water -- up to 20,000 cubic metres (706,000 cubic feet) -- per well, according to industry figures.

-- Four-year-old daughter died from a tumour --

The disposal of wastewater laced with corrosive salts, carcinogens and natural radioactive elements is another worry in an area where villagers grow their own fruit and vegetables and raise livestock.

"I have three children and I want them to grow up in a safe environment with clean water," said Alina Secriaru, a nurse from Barlad.

"Who will be willing to buy wheat, cheese or fruit" if millions of litres of toxic water are handled in the region?, Laiu asks.

Chevron spokeswoman Sally Jones stressed to AFP that it "operates at the highest standards in terms of safety and environmental protection".

The company "remains committed to being a responsible partner in Romania ... actively contributing to the local communities in which it operates", she added.

But Father Laiu says the villagers are being ignored: "Parishioners found prospecting equipment sinking pipes into fields without prior notice. Then they saw the walls crack" on their buildings, he said.

The priest's steadfast stance has impressed many.

"He stayed with us when politicians who were on our side last year abandoned us," said notary and anti-fracking campaigner Lulu Finaru.

Prime Minister Victor Ponta's centre-left coalition, including the Barlad mayor and local MPs, had initially slammed the previous government's decision to grant shale gas concessions.

Ponta, in power since May 2012, even put a moratorium on drilling.

But since that moratorium expired in December, the PM and rival President Traian Basescu have become leading European supporters of shale energy.

A US study estimated the joint reserves for Romania, Bulgaria and Hungary at around 538 billion cubic metres, possibly making it the biggest deposit in eastern Europe.

"Britain and Poland are looking to exploit shale gas. I do not think they would do something bad for the people," Barlad Mayor Constantin Constantinescu now argues.

But Laiu remains determined to make the voice of the locals heard.

"Years ago, my four-year old daughter died from a tumour. When I asked the doctor why, he answered: 'Only God knows, father. But we are too close to Chernobyl and that could be the cause'.

"I cannot remain indifferent when the environment is concerned. Life is more valuable than any money they offer us," Laiu said.

]]> Wed, 12 JUN 2013 00:37:26 AEST Washington DC (SPX) Jun 06, 2013 - It's not easy going green. For home lighting applications, organic light emitting diodes (OLEDs) hold the promise of being both environmentally friendly and versatile. Though not as efficient as regular light-emitting diodes (LEDs), they offer a wider range of material choices and are more energy efficient than traditional lights. OLEDs can also be applied to flexible surfaces, which may lead to lights or television displays that can be rolled up and stowed in a pocket.

A promising line of research involves combining the OLEDs with inorganic quantum dots, tiny semiconductor crystals that emit different colors of light depending on their size. These "hybrid" OLEDs, also called quantum dot LEDs (QD-LEDs), increase the efficiency of the light-emitting devices and also increase the range of colors that can be produced. But commercially manufacturing this promising green technology is still difficult and costly.

To make OLEDs more cheaply and easily, researchers from the University of Louisville in Kentucky are developing new materials and production methods using modified quantum dots and inkjet printing. The team will discuss its work developing more commercially feasible QD-LED devices at the Conference on Lasers and Electro-Optics (CLEO: 2013) June 9-14 in San Jose, Calif.

According to Delaina Amos, professor at the University of Louisville and principal investigator of the team's efforts, expense of materials and manufacturing processes has been a major barrier to using OLEDs in everyday lighting devices.

To inexpensively apply the quantum dots to their hybrid devices, the Louisville researchers use inkjet printing, popular in recent years as a way to spray quantum dots and OLED materials onto a surface with great precision.

But unlike other groups experimenting with this method, Amos' team has focused on adapting the inkjet printing technique for use in a commercial setting, in which mass production minimizes expense and translates to affordable off-the-shelf products.

"We are currently working at small scale, typically 1 inch by 1 inch for the OLEDs," Amos says. "The process can be scaled up from here, probably to 6 inches by 6 inches and larger."

"There's a reason you don't see OLED lights on sale at the hardware store," says Amos, though she adds that they do find uses in small devices such as cameras, photo frames, and cell phone displays. To bring their QD-LEDs closer to becoming market-ready as household lighting appliances, Amos and her team have been synthesizing new, less expensive and more environmentally friendly quantum dots.

The team has also modified the interfaces between the quantum dots and other layers of the OLED to improve the efficiency with which electrons are transferred, allowing them to produce more efficient light in the visible spectrum.

In addition to their higher efficiency, wider range of colors, and ability to be applied to flexible surfaces, Amos' QD-LEDs also use low-toxicity materials, making them potentially better for the environment.

"Ultimately we want to have low cost, low toxicity, and the ability to make flexible devices," Amos says.

The team has recently demonstrated small working devices, and Amos adds that she hopes to have larger devices within the next several months.

CLEO: 2013 presentation CF1M.3. "Printed Hybrid Quantum Dot Light-Emitting Diodes For Lighting Applications" by Delaina A. Amos is at 9:15 a.m. on Friday, June 14 in the San Jose Convention Center.

]]> Wed, 12 JUN 2013 00:37:26 AEST Washington (AFP) June 04, 2013 - China and India on Wednesday were again exempted from US sanctions aimed at choking off Iran's oil exports after significantly cutting back on purchases of crude from the Islamic republic.

"The United States and the international community stand shoulder to shoulder in maintaining pressure on the Iranian regime until it fully addresses concerns about its nuclear program," US Secretary of State John Kerry said.

He said in a statement that Beijing and New Delhi were among 20 countries which "have again qualified for an exception to sanctions" due to "significant reductions in the volume of their crude oil purchases from Iran or for reducing those purchases to zero and remaining there."

Other countries also granted exemptions from any sanctions were Malaysia, South Korea, Singapore, South Africa, Sri Lanka, Turkey and Taiwan, with the rest coming from Europe.

The US administration ruled that the economies concerned had taken steps to reduce imports of Iranian oil, so their financial institutions would not face measures under US law aimed at curbing Tehran's nuclear program.

Under US sanctions legislation the administration is bound by law to reconfirm the exemptions every six months.

"The message to the Iranian regime from the international community is clear: take concrete actions to satisfy the concerns of the international community, or face increasing isolation and pressure," Kerry said.

Under a 2011 law approved last year, the United States threatened to penalize foreign financial institutions over transactions with Iran's central bank, which handles sales of the country's key export.

There have been 10 failed meetings between the International Atomic Energy Agency (IAEA) and Iran over the past 18 months, as negotiators aim to get Tehran to rein in its suspect nuclear program.

On Wednesday the six world powers engaged in the stalled talks said it was "essential and urgent for Iran to engage with the agency on the substance of its concerns."

Western countries and Israel have accused Iran of seeking to develop atomic weapons, while Tehran insists its nuclear program is entirely peaceful.

]]> Wed, 12 JUN 2013 00:37:26 AEST Sydney (UPI) Jun 5, 2013 - Australia may have more than a sextillion cubic feet of shale gas resources, a new study indicates, more than double the size of current estimates.

But the researchers say additional environmental assessment and robust regulatory procedures are needed before the country can benefit from the potential shale gas bonanza.

The Australian Council of Learned Academies, the federal government's top research council, in its "Engineering Energy: Unconventional Gas Production" report released Wednesday, said obstacles to Australian shale development include lack of available pipelines, meaning shale gas would cost about $6 to $9 per gigajoule to produce, compared with less than $4 in the United States.

Report co-author Professor Peter Cook cautioned rigorous background work on Australia's shale gas is needed to avoid the controversy that has plagued the country's coal seam gas sector.

"You need a regulatory regime that is transparent," he told Guardian Australia. "You need to know what the impact is going to be, rather than rely on a high degree of speculation. That has caused angst around coal seam gas."

Community opposition in New South Wales has led the government to ban coal-seam gas exploration or production in many parts of the state.

The report said energy companies are planning to invest an estimated $500 million in shale exploration in the next few years. Santos is already producing shale gas in the Cooper Basin in central Australia and is planning more wells there and in the Northern Territory, The Age reports.

Groundwater, Cook said, "clearly needs to be safeguarded" to prevent contamination from hydraulic fracturing, or fracking. Fragmentation of landscapes with roads and drilling is also of concern.

"We won't see a shale gas boom here as we have in North America. It will be more modest growth, but what might really push it along is the oil associated with the gas," he said.

"Oil is what is driving the industry in North America. Gas is almost a byproduct. Things will move very quickly if they find oil amongst the shale gas here, because Australia doesn't have much oil. But we just don't know what's down there yet."

Meanwhile, Australia's high dollar, green tape, and escalating labor and construction costs have hindered investment in resource projects.

Speaking in Adelaide last month, Australian Resources Minister Gary Gray said development of shale "will drive once again prosperity through a manufacturing sector and it will drive prosperity through downward pressure on domestic gas prices."

]]> Wed, 12 JUN 2013 00:37:26 AEST Subscribe to our daily selection of space, military, environment and energy newsletters responseText http://visitor.constantcontact.com/manage/optin/ea?v=0016gbbKsaiGSpQFojVO8ZoHw%3D%3D