Showing posts with label ocean. Show all posts
Showing posts with label ocean. Show all posts

June 06, 2014

China looking seriously at creating artificial islands that near the scale of Manhattan as they also literally level Mountains for City Space

A new floating city designed by AT Design Office and the Chinese construction firm CCCC, is slated to begin development on a pilot scale next year.

“When the client came to us and talked about this project, I couldn’t believe it was true until I saw their technology,” says Anthony Phan, an architect at AT Design Office. CCCC, which commissioned the design, is currently building a 31-mile long bridge between Hong Kong and Macau using the same type of floating modules that will make up the new city.

Large prefab blocks join together to form the base of the 10-square kilometer island [Manhattan is 59 square kilometers], which will be filled with everything you'd expect on land. In theory, residents could spend all of their time in the new city.

“People won’t need to commute for jobs on land,” says Phan. “Work, apartments, entertainment and parks are all provided in the floating island.”

A large Chinese property investment firm is reviewing the design now and expected to begin testing some of its components in 2015.

China is among the countries which have built the most artificial land; from 1949 to 1990s, the total area of land reclamations from sea of China was about 12,000 km2 Land reclamation, usually known as reclamation, and also known as land fill (not to be confused with a landfill), is the process of creating new land from ocean, riverbeds, or lake. The land reclaimed is known as reclamation ground or land fill.

Tokyo Bay, Japan had 249 square kilometers reclaimed, including the entirety of Odaiba artificial island.

The largest artificial islands from reclaimed land.

April 05, 2014

Enceladus is the most habitable place in the solar system after Earth

Saturn's icy moon Enceladus is emerging as the most habitable spot beyond Earth in the Solar System for life as we know it. "It has liquid water, organic carbon, nitrogen [in the form of ammonia], and an energy source," says Chris McKay, an astrobiologist at NASA's Ames Research Center in Moffett Field, California. Besides Earth, he says, "there is no other environment in the Solar System where we can make all those claims."

A new study suggests that the ocean of Enceladus makes contact with the moon's rocky silicate core, which means that the water may soak up elements like sulfur and phosphorus that are important for life's complex chemical reactions.

"That silicate provides potentially some of the materials necessary for life," says Cornell University astronomer Jonathan Lunine, one of the study's authors. "So it makes, in fact, the interior of Enceladus a very attractive potential place to look for life."

Heat output from the south polar region of Saturn's moon Enceladus is far greater than was previously thought possible, according to a new analysis of data collected by NASA's Cassini spacecraft, published in the Journal of Geophysical Research on March 4. Data from Cassini's composite infrared spectrometer of Enceladus' south polar terrain, which is marked by linear fissures, indicate that the internal heat-generated power is about 15.8 gigawatts, approximately 2.6 times the power output of all the hot springs in the Yellowstone region, or comparable to 20 coal-fueled power stations.

The moon's heat is more than an order of magnitude higher than scientists had anticipated, according to Carly Howett, the lead author of study, at Southwest Research Institute in Boulder, Colo., and a composite infrared spectrometer science team member.

Astrobiology - Follow the Plume: The Habitability of Enceladus

The astrobiological exploration of other worlds in our Solar System is moving from initial exploration to more focused astrobiology missions. In this context, we present the case that the plume of Enceladus currently represents the best astrobiology target in the Solar System. Analysis of the plume by the Cassini mission indicates that the steady plume derives from a subsurface liquid water reservoir that contains organic carbon, biologically available nitrogen, redox energy sources, and inorganic salts. Furthermore, samples from the plume jetting out into space are accessible to a low-cost flyby mission. No other world has such well-studied indications of habitable conditions. Thus, the science goals that would motivate an Enceladus mission are more advanced than for any other Solar System body. The goals of such a mission must go beyond further geophysical characterization, extending to the search for biomolecular evidence of life in the organic-rich plume

Carnival of Space 348

The Carnival of Space 348 is up at Aartscope

Meridiani Journal - The sea of Enceladus: Cassini confirms underground ocean on Saturn’s geyser moon

Researchers have discovered a deep saltwater ocean on one of the many small moons that orbit Saturn, leading scientists to conclude it is the most likely place in the solar system for extraterrestrial life to be found.

Gravitational field measurements taken by Nasa's Cassini space probe revealed that a 10km-deep ocean of water, larger than Lake Superior, lurks beneath the icy surface of Enceladus at the moon's south pole.

David Stevenson, a planetary scientist at the California Institute of Technology in Pasadena, said the body of water was so large it "may extend halfway or more towards the equator in every direction. It might even extend all the way to the north."

An artist's impression of the interior of Saturn's moon Enceladus, based on data from the Cassini space probe suggesting the moon contains a water ocean beneath its south pole. Illustration: Nasa/JPL-Caltech

Understanding the interior structure of 500 km-diameter Enceladus has been a top priority of the Cassini mission since plumes of ice and water vapour were discovered jetting from ‘tiger stripe’ fractures at the moon’s south pole in 2005.

Science Cassini Plumbs the Depths of the Enceladus Sea

Science - The Gravity Field and Interior Structure of Enceladus

February 25, 2014

Robot Cargo Ships could have 20-50% lower operating costs

Rolls-Royce is designing unmanned cargo ships. Control centers will command hundreds of crewless ships.

Drone ships would be safer, cheaper and less polluting for the $375 billion shipping industry that carries 90 percent of world trade, Rolls-Royce says. They might be deployed in regions such as the Baltic Sea within a decade, while regulatory hurdles and industry and union skepticism about cost and safety will slow global adoption, said Oskar Levander, the company’s vice president of innovation in marine engineering and technology.

Researchers are preparing the prototype for simulated sea trials to assess the costs and benefits, which will finish next year

The company’s schematics show vessels loaded with containers from front to back, without the bridge structure where the crew lives. By replacing the bridge -- along with the other systems that support the crew, such as electricity, air conditioning, water and sewage -- with more cargo, ships can cut costs and boost revenue. The ships would be 5 percent lighter before loading cargo and would burn 12 percent to 15 percent less fuel.

Crew costs of $3,299 a day account for about 44 percent of total operating expenses for a large container ship.

January 24, 2014

China warns foreign planes entering defense zone

The AP reports taht China said Friday it has begun issuing warnings to foreign military planes entering its self-declared air defense zone over the East China Sea amid heightened tensions with its neighbors, especially Japan.

Chinese state media quoted air force spokesman Shen Jinke as saying several kinds of Chinese planes recently patrolled the sweeping zone that was declared in November. He said the planes identified several foreign military aircraft, flew alongside them and issued them warnings. He didn't identify the planes or say when the patrol was conducted.

The zone is a "purely defensive measure that conforms to international practice," Shen said.

The U.S., Japan and other countries denounced the zone's declaration in November as provocative and said they would ignore China's demands that their military aircraft announce flight plans, identify themselves and follow Chinese instructions. China has said it would take unspecified measures against aircraft that disobey.

November 01, 2013

Petrobras will increase oil production capacity by 1 million barrels per day in 2013

This year, Petrobras bring online nine new production units in a single year for the first time; the installed production capacity of the platforms amounts to 1 million barrels per day. The units coming on stream will be essential for the company to double its current production and achieve the target of 4.2 million barrels of oil per day for 2020.

The President also highlighted the growth of the shipbuilding industry in recent years.

September 26, 2013

Chinese telecom billionaire moving to build Nicaragua Canal

A Chinese telecom billionaire has signed a deal with the government of Nicaragua to build a $40 billion canal across Nicaragua.

Panama is now trying to complete a $5.25-billion reconstruction by mid-2015 that will greatly enhance the channel’s capacity. It’s not clear that the world’s largest shipping companies will continue, or resume, using the Panama route.

Earlier this year, Danish-owned Maersk Line, the planet’s biggest fleet of container vessels, announced it would cease traversing Panama owing to a combination of high tolls and uneconomical restrictions on ship size.

The size of container ships is measured in something called “20-foot equivalent units,” or TEUs, each of which approximates the length of a single cargo container. At present, the Panama Canal can handle vessels measuring up to 4,500 TEUs, a benchmark known in the industry by the abbreviation “Panamax.”

With the addition of two new systems of locks as well as the dredging of existing channels, the waterway will be able to handle ships measuring as much as 12,000 TEUs, which insiders already refer to as “New Panamax.”

There are already 18,000 TEUs cargo ships being built, while container ships of the near future may well be as large as 30,000 TEUs. Built from scratch, a Nicaragua canal could be far better equipped to handle the new seaborne giants.

The Nicaragua canal could start construction late in 2014 and complete by 2019.

September 08, 2013

Long term effort to develop capability to drill to the Earth's Mantle

The Integrated Ocean Drilling Program (IODP) is an international marine research program dedicated to advancing scientific understanding of Earth by sampling, instrumenting and monitoring subseafloor environments. Through multiple platforms-JOIDES Resolution, Chikyu and Mission-Specific-Platforms-some of the world's preeminent scientists explore the deep biosphere and subseafloor; environmental change; Earth processes and effects; and solid earth cycles and geodynamics; and other themes.

One of the missions will be to drill 6 km (3.7 miles) beneath the seafloor to reach the Earth's mantle -- a 3000 km-thick layer of slowly deforming rock between the crust and the core which makes up the majority of our planet -- and bring back the first ever fresh samples.

They must first find a way to grind their way through ultra-hard rocks with 10 km-long (6.2 miles) drill pipes.

They have already identified three possible locations -- all in the Pacific Ocean -- where the ocean floor was formed at relatively fast spreading mid-ocean ridges, says Teagle.

The hole they will drill will be just 30 cm in width all the way from the ocean floor to inside the mantle -- a monumental engineering feat.

IODP's initial 10-year, $1.5 billion program is supported by two lead agencies, the U.S. National Science Foundation (NSF) and Japan's Ministry of Education, Culture, Sports, Science, and Technology (MEXT).

If Japanese support can be combined with other funding, Teagle says they could start drilling before the end of the decade, making it possible for humans to finally reach the Earth's mantle by the early 2020s.

May 15, 2013

New metal-organic framework four times better at extracting uranium from seawater

The most advanced system today for extracting uranium from seawater employs plastic fibers with uranium-binding chemical groups grafted onto their surface. Now, researchers led by Wenbin Lin, a professor of chemistry at the University of North Carolina at Chapel Hill, have designed a metal-organic framework (MOF) to collect common uranium-containing ions dissolved in seawater. In lab tests, the material was at least four times better than the conventional plastic adsorbent at drawing the potential nuclear fuel from artificial seawater.

Metal-organic frameworks are considered very promising for certain technological applications, including gas storage and chemical separation. Their structure can be tuned for different purposes. This allows them to be made extremely porous, resulting in very high surface areas—an order of magnitude larger than that of zeolites, a porous material already used in many commercial adsorbents. And like organic polymers, metal-organic frameworks have surfaces that can be modified so as to bind to specific molecules.

There is about 4 billion tons of uranium in the oceans. This is about 600 times the total uranium reserves on land.

April 25, 2013

Lockheed 10 megawatt ocean thermal energy plant could finally be beginning of utility scale commercialization

Lockheed Martin recently entered into an agreement with Beijing based Reignwood Group to develop and build a 10-megawatt Ocean Thermal Energy Conversion (OTEC) pilot power plant off the coast of southern China.

The offshore plant, to be designed by Lockheed Martin, will be the largest OTEC project developed to date, supplying 100 percent of the power needed for a green resort being developed by Reignwood. In addition, the agreement could lay the foundation for the development of several additional OTEC power plants, ranging in size from 10 to 100 megawatts, for a potential multibillion-dollar value.

Southern China is an ideal location for an OTEC plant, which uses the natural temperature differences found in the ocean of tropical regions to drive turbines that create electricity. The energy produced by an OTEC facility is clean, sustainable and well-suited to the ocean conditions found near 80 countries around the world, including in the Asia-Pacific.

Once the plant is operational, the two companies plan to use the knowledge gained to improve the design of the additional commercial-scale plants to be built over the next 10 years.

OTEC has the potential to offer global amounts of energy that are 10 to 100 times greater than other ocean energy options such as wave power. OTEC plants can operate continuously providing a base load supply for an electrical power generation system.

A US Dept of Energy study indicated a maximum for global OTEC power production of 30 terawatts. More modest scenarios show 7 terawatts having little impact.

March 25, 2013

Uranium from Seawater is over 3000 times the energy of Methane Hydrate in the Ocean

Japan has extracted gas from offshore deposits of methane hydrate — sometimes called “flammable ice” — a breakthrough that officials and experts said could be a step toward tapping a promising but still little-understood energy source. Japan hopes to make methane hydrate commercially viable in 5 years.

With specialized equipment, the team drilled into and then lowered the pressure in the undersea methane hydrate reserve, causing the methane and ice to separate. It then piped the natural gas to the surface. The surrounding area in the Nankai submarine trough holds at least 1.1 trillion cubic meters, or 39 trillion cubic feet, of methane hydrate, enough to meet 11 years’ worth of gas imports to Japan.

A separate rough estimate by the National Institute of Advanced Industrial Science and Technology has put the total amount of methane hydrate in the waters surrounding Japan at more than 7 trillion cubic meters, or what researchers have long said is closer to 100 years’ worth of Japan’s natural gas needs.

The EIA estimates the naturally occurring gas hydrate resource vary from 10,000 trillion cubic feet to more than 100,000 trillion cubic feet of natural gas. The 100,000 trillion cf would be an energy resource of 105,000 EJ. Tapping such resources would require significant additional research and technological improvements

There is about 4.4 billion tons of uranium in seawater. Deep burn nuclear fission (where reactors that can burn all of the uranium for energy) would enable 217 million EJ of energy to be produced.

There has been progress towards making extracting uranium from seawater affordable.

Japan has found rare earth reserves in the Pacific Seabed that are 1000 times all land based deposits

Japanese scientists have found vast reserves of rare earth metals on the Pacific seabed that can be mined cheaply, a discovery that may break the Chinese monopoly on a crucial raw material needed in hi-tech industries and advanced weapons systems.

"We have found deposits that are just two to four metres from the seabed surface at higher concentrations than anybody ever thought existed, and it won't cost much at all to extract," said professor Yasuhiro Kato from Tokyo University, the leader of the team.

While America, Australia, and other countries have begun to crank up production of the seventeen rare earth elements, they have yet to find viable amounts of the heavier metals such as dysprosium, terbium, europium, and ytterbium that are most important.

Beijing shocked the world when it suddenly began to restrict exports in 2009, prompting furious protests and legal complaints by both the US and the EU at the World Trade Organisation. China claimed that it was clamping down on smuggling and environmental abuse.

"Their real intention is to force foreign companies to locate plant in China. They're saying `if you want our rare earth metals, you must build your factory here, and we can then steal your technology," said professor Kato.

The team of scientists from Japan's Agency for Marine-Earth Science and the University of Tokyo first discovered huge reserves in the mid-Pacific two years ago. These are now thought to be 1000 times all land-based deposits, some of it in French waters around Tahiti.

February 18, 2013

Next Generation Fish Farming will Multiply the Yield

Improvements in fish-farm construction are also expected to boost aquaculture production.

1. Split Ponds for Boosting Yield

Catfish farmers have found success with split-pond designs. Such a design entails separating a smaller area, where the fish are kept, from a much larger area, where the water is treated. Split-pond farming has helped catfish farmers see their yields triple to 15,000 pounds per acre from 5,000 pounds per acre in the last several years, according to Silverstein.

2. Microbial Fish Food

Frequently, farmed fish have to be fed fish oil near the end of their lives to help make them healthier for humans to eat. One of the ways to mitigate that dip in nutrition could be to turn to an alternative source of fish food: microbes.

Researchers are currently trying to perfect the production of various microbes that could bulk up a farmed fish’s diet, thereby cutting the amount of food and agricultural land used indirectly by fish food production.

Margareth Overland, a nutritionist with the Aquaculture Protein Center at the Norwegian University of Life Sciences, said one of the more promising microbial sources for fish food is yeast grown on processed spruce wood. Algae and bacteria are also being studied.

However, microbe-based food is years away from being ready to supply large industries, and researchers still need to conduct taste tests to make sure there's nothing especially fishy about a salmon that's been dining on yeast.

February 04, 2013

An economical way to convert carbon dioxide into calcium carbonate

A chance discovery that sea urchins use Nickel particles to harness carbon dioxide from the sea to grow their exoskeleton could be the key to capturing tonnes of CO2 from the atmosphere.

Experts at Newcastle University, UK, have discovered that in the presence of a Nickel catalyst, CO2 can be converted rapidly and cheaply into the harmless, solid mineral, calcium carbonate.

The process developed by the Newcastle team involves passing the waste gas directly from the chimney top, through a water column rich in Nickel nano-particles and recovering the solid calcium carbonate from the bottom. They are looking for business partners to develop their patented process.

November 26, 2012

Low cost geo-engineering and actual field tests

The cost to construct a Stratospheric Shield with a pumping capacity of 100,000 tons a year of sulfur dioxide would be roughly $24 million, including transportation and assembly. Annual operating costs would run approximately $10 million. The system would use only technologies and materials that already exist—although some improvements may be needed to existing atomizer technology in order to achieve wide sprays of nanometer-scale sulfur dioxide particles and to prevent the particles from coalescing into larger droplets. Even if these cost estimates are off by a factor of 10 (and we think that is unlikely), this work appears to remove cost as an obstacle to cooling an overheated planet by technological means.

1/20th Scale Testing of Aerosols to the Stratosphere was funded but the actual test called off

British researchers supported by the U.K. government were attempt to pump water a kilometer into the air using little more than a helium balloon and a rubber hose. The experiment, which was to take place at a military airfield along England's east coast, was meant as a test of a proposed geoengineering technique for offsetting the warming effects of greenhouse gases. If the balloon and hose could handle the water's weight and pressure, similar pipes rising 20 kilometers could pump tons of reflective aerosols into the stratosphere.

In May 2012 this first field test was cancelled altogether in agreement of all project partners. Dr. Matthew Watson, the project´s lead scientist, named two reasons for the cancellation: First, involved scientists had submitted patents for similar technology, presenting a potentially significant conflict of interest. In addition to that, concerns about the lack of government regulation of such geoengineering projects were raised Although the field testing was cancelled, the project panel decided to continue the lab-based elements of the project.

October 21, 2012

Rogue Geoengineering to create algae bloom ten times larger than past tests

Guardian UK - An American businessman conducted a massive ocean fertilisation test, dumping around 100 tonnes of iron sulphate off Canada's coast, it has emerged the Canadian government may have known about the geoengineering scheme and not stopped it.

Satellite images appear to confirm the claim by Californian Russ George that the iron has spawned an artificial plankton bloom as large as 10,000 square kilometres. The intention is for the plankton to absorb carbon dioxide and then sink to the ocean bed – a geoengineering technique known as ocean fertilisation that he hopes will net lucrative carbon credits.
The algae bloom was apparently ten times larger than any previous test.

September 17, 2012

Strait of Hormuz and other Oil Chokepoints

In January, 2012 we had looked at what would happen the Straits of Hormuz an oil movement if there was war with Iran and the economic impact of Iran attempting to shut the Straits of Hormuz. This is an update.

Iran currently is not exporting much, about 1 million barrels per day.

So an attack that shutdown Iranian exports would be less impactful than the Libyan situation last year.

Iran would attempt to mine and shutdown the straits of hormuz. 17 million barrels goes through the Straits of Hormuz.

Pentagon officials estimate if Iran was foolish enough to try and close the Strait of Hormuz using its estimated arsenal of 2,000 mines, the US Navy and allied nations would be able to clear it in five to ten days. That's just long enough to likely cause massive spikes in worldwide oil prices, disrupt global shipping traffic. "If they wanted to close the Strait of Hormuz, they could do it, but they would only be able to do it one time," Christopher Harmer, a retired Navy commander who served as director of future operations at U.S. 5th Fleet headquarters in Bahrain, told KTLA

September 16, 2012

Path to Affordable uranium from seawater

IEEE Spectrum - Our oceans contain an estimated 4.5 billion metric tons of uranium, diluted down to a minuscule 3.3 parts per billion. The idea of extracting uranium from seawater has been kicking around for decades now, but the materials and processes to do so may finally be economically viable.

The best method works like this: A polymer substrate—basically, plastic—is irradiated, and then chemicals with an affinity for uranium are grafted onto it. The material is woven into 60-meter-long braids, and these are then brought out by boat to water at least 100 meters deep. The braids are chained to the ocean floor and allowed to float passively in the water, like an artificial kelp forest. After about 60 days, the boat returns and pulls in the adsorbent materials—now sporting a healthy yellow tint from the uranium. The plastic is then brought back to shore, and the uranium is eluted off.

August 24, 2012

Abstracts from the Extracting Uranium from Seawater Conference

Here is the link to all of the presentations and abstracts from papers for the ACS Extraction of Uranium from Seawater conference

1. American Chemical Society Meeting - "Life cycle cost and energy balance of uranium recovered by a braid adsorbent system" paper by Erich Schneider

Life cycle discounted cash flow and inventory analysis methods are used to estimate the production cost and energy return on investment (EROI) of uranium recovered from seawater via a polyethelene-based braid type adsorbent. The estimates are built on original assessments of the cost and energy intensity of materials, capital equipment, labor and other inputs to the uranium production chain. If fresh adsorbent achieves a capacity of 2 grams of uranium (g U) / kg ads, as in trials off the coast of Japan, and the adsorbent may be reused 6 times with capacity degradation of 5% per recycle, the U production cost is estimated at $1230/kg U with a 95% confidence interval of [$1030/kg U, $1430/kg U]. If this uranium is used in a once-through fuel cycle, the EROI is found to be 22. Improving the capacity of the multi-recycled adsorbent to 6 g U/kg ads would reduce the cost by approximately a factor of three, as would attaining a very high capacity -- 20 g U/kg ads -- in a single-use adsorbent.

World Nuclear News - previous experiments have collected uranium from ocean currents by submerging long fibrous mats embedded with specially designed adsorbent compounds that chemically bind to uranium. After a few weeks in the sea, the mats are washed in mild acid to release the uranium and go on to be reused several times. Although these trials proved the principle of uranium extraction from seawater, the cost was prohibitively high - perhaps around $260 per pound. This compares badly to today's most economic mines on land, which produce uranium at around $20 per pound, while resources at higher costs up to about $115 per pound have already been identified that would last more than a century.

The latest research on seawater extraction was discussed at an American Chemical Society's (ACS's) meeting in Philadelphia and two groups presented new fibre technologies that stand to dramatically boost uranium recovery.

Conducting research for the US Department of Energy, Oak Ridge National Laboratory has worked with Florida firm Hills Inc to develop new adsorbent materials. Mats made from so-called 'HiCap' fibres, featuring high surface-areas, are irradiated and then reacted with chemical compounds that have an affinity for uranium. After an exposure period and extraction of uranium the mats require acid washing and conditioning with potassium hydroxide before re-use.

Oak Ridge said the fibres delivered five-times higher adsorption capacity, faster uptake and higher selectivity than the previous best. "These results clearly demonstrate that higher surface areas fibres translate to higher capacity," said Chris Janke, who led the project.

Another project presented at the ACS meeting concerned the use of fibres based on chitin - a long chain biopolymer that can be obtained from shrimp shells. Scientists at the University of Alabama led by Robin Rogers have been working to create a high-surface-area sorbent material from chitin resins sourced from the fishing industry. Rogers hopes the fibre may further help extraction of uranium from seawater.

The ACS summarised the session saying that the new techniques might reduce the cost of uranium from seawater to around $135 per pound. While this price remains uneconomic, the cost of nuclear fuel makes up only about 5% of the final cost of nuclear power. In this context, the feasibility of vastly increasing available supplies of uranium by tapping seawater, even at higher cost, assures nuclear power a feasible fuel supply for millennia to come. Further extensions to the resource timeframe could also be made by recycling uranium from used nuclear fuel, using advanced reactors that run on materials currently thought of as waste, or units that produce fissile fuel from non-fissile elements as they operate.

August 23, 2012

Uranium from seawater idea boosted with shrimp shells

BBC News - A report at the 244th meeting of the American Chemical Society described a new technique using uranium-absorbing mats made from discarded shrimp shells. The oceans hold billions of tonnes of uranium at tiny concentrations, but extracting it remains uneconomical.

Although these trials proved the principle of uranium extraction from seawater, the cost was prohibitively high - perhaps around $260 per pound. This compares badly to today's most economic mines on land, which produce uranium at around $20 per pound, while resources at higher costs up to about $115 per pound have already been identified that would last more than a century. The ACS summarised the session saying that the new techniques might reduce the cost of uranium from seawater to around $135 per pound.

Previously Japanese researchers had a design of a mat of plastic fibres impregnated with molecules that both lock onto the fibres and preferentially absorb uranium. That work culminated in a 2003 field test that netted a kilogram of the metal.

The mats can reach 100m in length, suspended underwater at depths up to 200m. They are withdrawn and rinsed with an acid solution that frees the uranium, and the cycle is repeated.

New research has focussed on improving both the braided fibres of the mat and the "ligand" that captures the uranium, which has most often been a molecule called poly-acrylamidoxime.

Several groups at the conference said they had been working on variations on this molecular theme, or variants of porous "nanoparticles" made of silica (the stuff of sand) or carbon.

Robin Rogers of the University of Alabama, who organised the symposium, outlined an improvement developed in his own group: seafood shells.

He said that in the wake of both Hurricane Katrina and the BP oil spill in the region, "we began working with the Gulf Coast Agricultural and Seafood Co-operative... and with the shrimpers and crabbers there, and found they were paying hundreds of thousands of dollars to get rid of their waste [shells]".

"We discovered an 'ionic liquid' - a molten salt - could extract a very important polymer called chitin directly from shrimp shells," he added.