It was a natural phenomenon that would have tested the limits of even Mr Muscle.Scientists in Japan have found that clouds generated by a massive dust storm in China's Taklimakan desert in 2007 completed more than one full circle around the planet in just 13 days.And measuring around 1.9 miles vertically and up to 1,242 miles horizontally, the dust cloud - which formed in the northwestern region of Xinjiang - stayed in that formation the whole way. 
(Phenomenal: An enormous dust cyclone swirls over northeastern China)When it reached the Pacific Ocean the second time around, it descended and deposited some of its dust into the sea.'Asian dust is usually deposited near the Yellow Sea, around the Japan area, while Sahara dust ends up around the Atlantic Ocean and coast of Africa,' said Itsushi Uno of Kyushu University's Research Institute for Applied Mechanics.'But this study shows that China dust can be deposited into the (Pacific Ocean). Dust clouds contain 5 per cent iron, that is important for the ocean.'In a report published in Nature Geoscience, scientists described how they used a NASA satellite and mathematical modelling to track and measure the movement of the dust cloud, which formed after the storm between May 8 and 9 in 2007. The researchers found that the dust clouds were lifted 5-6 miles above the earth's surface before racing around the earth.'The most important achievement is that we tracked this through one full circuit round the globe - nobody has done this before,' said Mr Uno. 
(Full circle: Asian dust usually deposits near Japan but this cloud dropped the dust on its second tour of the Pacific, as pictured here)'After half a circuit, usually the dust concentration gets very low and you can't track it.'This means that dust concentration, dust lifetime is very long, more than two weeks.'The reason why the cloud structure was very well maintained was because the dust was uplifted - where the atmosphere is very stable.'Researchers believe dust particles trigger the formation of high-altitude cirrus clouds, although experts have no idea whether such clouds warm or cool the earth.* By DAILY MAIL REPORTER on 22nd July 2009
To truly appreciate how glass can be used structurally, make your way to 233 South Wacker Drive in downtown Chicago. More precisely, make your way 1,353 feet above South Wacker, to the 103rd floor of the Sears Tower.
Once there, take a few steps over to the west wall, where the facade has been cut away. Then take one more step, over the edge. You’ll find yourself on a floor of glass, suspended over the sidewalk a quarter-mile below. If you can’t bear looking straight down past your feet, shift your gaze out or up — the walls are glass, too, as is the ceiling. You’ve stepped into a transparent box, one of four that jut four and a half feet from the tower, hanging from cantilevered steel beams above your head.
The glass walls are connected to the beams, and to the glass floor, with stainless-steel bolts. But what’s really saving you from oblivion is the glass itself.
The boxes, which opened last week as part of an extensive renovation of the tower’s observation deck, are among the most recent, and more outlandish, projects that use glass as load-bearing elements.
But all glass structures have at least a bit of daring about them, as if they are giving a defiant answer to the question: You can’t do that with glass, can you? You can.
Engineers, architects and fabricators, aided by materials scientists and software designers, are building soaring facades, arching canopies and delicate cubes, footbridges and staircases, almost entirely of glass.
They’re laminating glass with polymers to make beams and other components stronger and safer — each of the Sears Tower sheets is a five-layer sandwich — and analyzing every square inch of a design to make sure the stresses are within precise limits. And they are experimenting with new materials and methods that could someday lead to glass structures that are unmarked by metal or other materials.
“Ultimately what we’re all striving for is an all-glass structure,” said James O’Callaghan of Eckersley O’Callaghan Structural Design, who has designed what are perhaps the world’s best-known glass projects, the staircases that are a prominent feature of some AppleStores. Through it all, they’ve realized one thing.
“Glass is just another material,” said John Kooymans of the engineering firm Halcrow Yolles, which designed the Sears Tower boxes. It’s a material that has been around for millennia. Although glass can be made in countless ways to have any number of specific uses — to conduct light as fibers, say, or serve as a backing for electronic circuitry, as in a laptop screen — structural projects almost exclusively use soda-lime glass, made, as it has always been, largely from sodium carbonate, limestone and silica.
“For years, the basic composition of soda-lime glass has not changed much,” said Harrie J. Stevens, director of the Center for Glass Research at Alfred University. It’s the same glass, more or less, that is used for the windows in your home and the jar of jam in your fridge — and that old elixir bottle you bought at an antique store.
It’s basic stuff, but far from simple. “Of course, glass is an unusual material,” said James Carpenter of James Carpenter Design Associates, who has designed glass facades and other structures and was a consultant for the glassmakerCorning in the 1970s. “Since we don’t really know what it is.” Although there has long been debate as to whether glass is a solid or liquid, it is now usually described as an amorphous solid (there is no evidence that it flows, extremely slowly, over time as a liquid).
The noncrystalline structure is achieved by relatively rapid cooling below what is referred to as the glass transition temperature, around 1,000 degrees Fahrenheit for the soda-lime variety. Cooled further and cut, pristine glass is very strong. But like a new car that plummets in value the moment it is driven off the lot, glass starts to lose its strength the instant it’s made.
Tiny cracks begin to form through contact with other surfaces, or even with water vapor and carbon dioxide. “If you take the freshly made surface and blow on it with your breath, you’ve reduced the strength of glass by a factor of two,” said Suresh Gulati, a mechanical engineer and self-described “strength man” who retired in 2000 after 33 years at Corning but still works for the company as a consultant.
Even one gas molecule can break a silicon-oxygen bond in glass, generating a defect, said Carlo G. Pantano, a professor of materials science at Pennsylvania State University. While glass is very strong in compression, tensile stresses will make these tiny fissures start to grow, bond by bond. “That’s what makes glass break,” Dr. Pantano said. “And if it doesn’t break, it weakens it.” Protective coatings are one way to avoid new cracks, although they can affect transparency, which is the main reason for using glass in the first place.
Changing the glass recipe can also make it harder for cracks to form and propagate. “There is some evidence that you can modify the composition to make it innately stronger,” Dr. Stevens said, although that risks altering other properties or making the glass too costly. (And glass projects are not cheap to start with; the glass in the Sears Tower project cost more than $40,000 per box.)
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The manufacturing process can be modified, too, to keep the surfaces of the glass as pristine as possible. In one technique, used for laptop glass, molten glass is pumped into a V-shaped trough, spills over on both sides and flows down the outside of the V, joining together at the bottom into a sheet that continues to move downward as it cools. This way, each side of the sheet is a “melt surface,” exposed only to the air and not touched by any part of the equipment.
For structural purposes, glass is often strengthened the old-fashioned way — by tempering. This puts the surface under compression, so that even more tensile force is needed for cracks to grow. For flat glass, heat tempering is most often used.
William LaCourse, a professor at Alfred, said the process took advantage of one property of glass — that when it cools slowly it becomes denser. By rapidly cooling the exterior of a sheet (usually with air), the surface stays less dense. “Inside it’s still hot, and tries to cool to a more dense structure,” Dr. LaCourse said.
“This pulls the surface into compression.” In chemical tempering, sodium ions in the surface are replaced with potassium ions, which are about 30 percent larger. It’s like taking a suitcase full of summer-weight clothes and replacing the top layer with winter-weight items; the suitcase will bulge at the seams when you try to close it. Glass cannot bulge at the seams, so the surface becomes compressed.
Tempered glass may take longer to crack, but it can still break. Because surface compression must be balanced by interior tension, when tempered glass does break it forms many more smaller pieces than untempered glass, as morefracture lines release more energy. “The more it is strengthened the more pieces it will fly into,” Dr. Gulati said. An extreme example of this is a Prince Rupert’s drop, a small glass ball with a long tail formed by dropping molten glass into water.
You can pound on the ball end with a hammer and it will not break, but snip off the tail and the ball will explode into tiny pieces as the tensile forces are released. In structural applications, breaking into smaller pieces is often preferred, because these have less chance of causing injury. But tempering alone is usually not enough. A primary concern when building with glass is what happens if and when a component breaks — what engineers call “post-failure behavior.”
Unlike steel or other materials, glass does not deform or otherwise give advance warning of failure. If breakage occurs, maintaining the integrity of the structure is paramount so that people on or below it are safe. That’s where lamination comes in. In a typical project, glass sheets (one-half-inch thick in the Sears Tower project) are bonded with thin polymer interlayers.
The interlayers add strength and, should one of the glass layers break, keep the structure together, and the pieces from falling. But lamination makes fabricating glass for structural uses very difficult. Since cutting into tempered glass causes it to break, each sheet must be polished and drilled for the connecting fittings before it is tempered. Tolerances are extremely small, to avoid potentially destructive stresses in the assembled structure.
“It’s doable,” said Lou Cerny of MTH Industries, who managed the installation at the Sears Tower, where the tolerances were one-sixteenth of an inch. “There’s just not a lot of people who want to get involved in it.” No wonder, then, that those who build with glass look forward to a day when their structures will be unencumbered by metal or other materials. “My goal has always been to reduce the amount of fittings in glass,” said Mr. O’Callaghan, whose Apple staircases use stainless steel and, occasionally, titanium to join the glass components. Already, some engineers are using different glass shapes to reduce the dependence on metal. Rob Nijsse, a professor at the Delft University of Technology in the Netherlands and a structural engineer with the firm ABT Belgium, has used large sheets of corrugated glass, mounted vertically, for window walls in a concert hall in Porto, Portugal, and a museum being built in Antwerp, Belgium. The shape helps stiffen the glass against wind loads. Other designers think about using different kinds of glass. “There are so many amazing types of glass available,” Mr. Carpenter said.
“There’s an enormous potential to transfer some of their characteristics into architectural uses.” Using a glass that does not expand much when heated, for example, would enable components to be welded together, forming, in effect, a continuous piece of glass. Conventional soda-lime glass expands too much, so welding introduces stresses that can lead to failure. Researchers at Delft have experimented with welding glass components. But low-expansion glass is much costlier than soda-lime glass. Other engineers are starting to use adhesives to join glass directly to glass. Lucio Blandini, an engineer with Werner Sobek Engineering and Design in Stuttgart, Germany, used adhesives to create a thin glass dome, 28 feet across, for his doctoral thesis in a clearing in Stuttgart.
“I think adhesives are the most promising connection device,” Dr. Blandini said. “It allows glass to keep its aesthetic qualities.” His firm is using adhesives in parts of structures being built at the University of Chicago and in Dubai. But the long-term strength and reliability of adhesives has not been proved, so most people who work in glass think an all-glued structure is a long way off.
“We have way too many lawyers in this country,” said Mr. Cerny, the installer at the Sears Tower. “It’ll be awhile before we see that.”
* Source: NYT, july 2009
Light-reflective dots attached to Emma Phibbs allowed a sophisticated camera system to capture her movement and display it on a monitor at the University of Delaware. Photo: Jessica Kourkounis for The New York Times
The system allows researchers to mimic skaters' positions during jumps and calibrate the effect of altering angles of the head, torso, arm and leg.
The light-reflective dots were also attached to Ms. Phibbs's skates.
Oxygen mask readings help gauge the aerobic conditioning skaters need, measuring the oxygen their muscles are consuming.
Ms. Phibbs inside a pod that measures fat and muscle composition.
Science is even filtering into recreational skating, with the development of synthetic ice, intended to broaden appeal and year-round interest.
(Photo: Dan Cappellazzo for The New York Times)
A skater on the synthetic ice at Snow Park Niagara Falls.
George Knakal, a former cabinetmaker who sharpens blades in Norwalk, Conn., pays close attention to several factors, including the concavity of the blade. A flat blade helps new skaters, he says.
The wall that faces Mr. Knakal's sharpening machine in his garage.
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Melissa Bulanhagui is a highly ranked figure skater, but two years ago her right ankle failed her. She sprained it twice and tore a ligament, each time during one of her favorite jumps, the triple lutz. Other skaters have suffered similar injuries, and now science is studying why, aiming to help skaters meet the sport’s physical challenges without sacrificing their health.
For one study, Ms. Bulanhagui (pronounced BULL-en-hayg-ee), 18, and other skaters tape to their shins devices called tibial accelerometers, which measure the force of the impact when skaters land a jump.
“A lot of the impacts are really high, 90 to 100 G’s,” said Kat Arbour, a skater turned graduate researcher at the University of Delaware. “If you hit your head that hard, I don’t think you’d survive.”
But she said study results suggested that the issue was not jumping itself, but how well jumps were executed. “If someone is really proficient, they seem to be able to modify their technique to decrease the impact, use muscles differently to absorb that shock,” she said.
The accelerometer study is part of a flowering of research on safety and performance. And it is no coincidence that such research is growing at a time when figure skating, a year-round pursuit for competitive skaters, emphasizes athleticism and endurance more than ever before.
Adjustments to international judging guidelines in 2003 made skating “much more physically and mentally challenging,” said Mitch Moyer, senior director of athlete high performance for United States Figure Skating, which is sponsoring the accelerometer study and others. Each skill in a performance now receives specific points, requiring more focus. And skaters no longer have an incentive to perform all jumps early in a program before they tire — now, jumps done later earn extra points.
“People said, ‘Oh, it’s an art,’ but the reality is it’s a very taxing sport,” said Michelle Provost-Craig, associate professor of exercise physiology at the University of Delaware. “Many skaters end up with stress fractures, knee problems and hip problems at a fairly young age.”
Research could inspire new training recommendations concerning issues like off-ice conditioning and limiting repetitions of jumps during practice. United States Figure Skating now has a sport sciences and medicine director, who works with scientific researchers and helps coaches monitor skaters’ health more closely and pace workouts.
“Coaches are paying a lot more attention to these things,” said Mr. Moyer, who said some concerns were set off by a “trend of hip issues” with skaters like the Olympic champion Tara Lipinski, whose hip injuries required surgery at 18. “I hear a lot more buzz out there — ‘you need to stop jumping, you’ve done enough today.’ ”
Scientists are looking at skating from every angle — biomechanics, physics, muscle conditioning, body fat, oxygen consumption,exercise-induced asthma. Ms. Arbour, of the University of Delaware, has skaters, wearing swimsuits and nose clips, climb into the “bod pod,” an egglike capsule measuring fat and muscle composition. A “bone densitometer” analyzes bone density, which tends to increase with frequent impacts.
“If it’s low, they are at risk for stress fractures in the legs and lumbar spine,” she said. “If it’s too high, they are at risk for osteoarthritisbecause the cartilage is taking a lot of shock absorption.” With Professor Provost-Craig, Ms. Arbour also outfits skaters with “a crazy dungeon thing that goes over the mouth and nose,” measuring oxygen and carbon dioxide in air skaters expel.
Science is even filtering into recreational skating, with the development of synthetic ice, intended to broaden appeal and year-round interest. But most research concerns competitive skaters.
Some researchers are interested, for example, in the sport’s effects on younger skaters, said Mr. Moyer, because “kids develop differently at different ages. If somebody’s injured at 14, was it because of what they were doing at 9 or 10, or at 14?”
Professor Provost-Craig plans to study whether certain jumps generate such physical impact that younger skaters should delay learning them. “A lutz might put more loading on a young skeletal developing frame than a toe loop,” she said. “They may choose, especially during a growth spurt, not to teach a new jump with extensive loading characteristics.”
Some research focuses on training and equipment. James Richards, senior biomechanist for the Human Performance Laboratory at the University of Delaware, designed a skate boot to provide flexibility for pointing toes and maneuvering feet.
Current boots are stiff for support, “comparable to a cast,” said Kelly Lockwood, an associate professor of physical education and kinesiology at Brock University in Ontario, preventing the ankle from absorbing enough impact. Professor Richards’s boot, hinged around the ankle, allowed flexibility but fell apart after about a month, he said. And skaters and coaches thought it unattractive.
“People were willing to give it a try if it was helping in impact and injury,” Mr. Moyer said. He said that Alissa Czisny, currently the national champion, wore the boots for a while, but that she and others “became frustrated with some of the challenges.”
He hopes the accelerometer study will indicate whether “one type of boot design or blade design could maybe reduce the stress load.” Professor Lockwood has studied something more rudimentary: how skate blades are sharpened. A blade’s bottom is not flat, but grooved to create two edges that grip the ice. A study with the National Hockey League of groin injuries found that “more than 50 percent of them are due to skate sharpening, way too deep a hollow” in the blade’s groove, which can give a player too much traction instead of allowing easy gliding, she said.
Sharpening, it turns out, is hard to do well, and sharpeners who earn respect from skaters and coaches have become scientists of sorts, too. George Knakal, a 79-year-old retired cabinetmaker turned sharpener in Norwalk, Conn., pays zealous attention to several factors, including the concavity of the blade. “For a new skater, I make it nearly flat because a little kid is very awkward and you want to give them something that will slip so when they fall they don’t get hurt,” he said.
Training when not on ice is another matter altogether, and theories differ about what off-ice conditioning is best.
“It’s a sport where you’re doing contradictory things,” said Deborah King, associate professor of exercise and sport sciences at Ithaca College. “Running or cycling or stair-stepping to improve aerobic capacity — does that translate really well on the ice, or is it better to do something more specific to skating? Do you need a lot of strength training in the gym or training to do the motion while rotating?”
Professor Provost-Craig said skaters should not “bulk up” from strength training because “if they increase girth of shoulders, hips or thighs, that’s going to decrease rotational spin.”
One recent invention for off-ice training is a block of wood topped with rubber, slanted to approximate angles of skaters’ blades on ice. Wearing skates on the block, skaters assume different positions.
“It will freeze-frame any on-ice technique and mimic as close as you possibly can the requirements for balance, that sensation of shifting your weight against momentum,” said its creator, David Lipetz, a physical therapist who is trying to get coaches and skaters to use the device.
Professor Provost-Craig’s oxygen mask readings help gauge the aerobic conditioning skaters need, measuring their “VO2 max,” she said, “oxygen their muscles are consuming” as they skate to increasingly fast music. More is better, improving endurance, for example, to do jumps later in performance. Professor King analyzed jumps in a different way. Studying Olympic skaters, she determined that on triple jumps, they went no higher than on double or single jumps — rather, they rotated faster by pulling in their arms, making their bodies compact.That guides one of Professor Richards’s more elaborate projects. With sophisticated motion-capturing cameras and computer programs, he mimics skaters’ positions during jumps and calibrates the effect of altering angles of the head, torso, arm and leg.
Consider Emma Phibbs, a 22-year-old pairs skater looking to make a comeback after scaling back skating in college. Recently, researchers affixed 38 quarter-size stickers — made from golf ball markers, children’s alphabet beads and reflective tape — all over Ms. Phibbs’s body and sent her skating. Doing triple toe loops and double axels, she wobbled on some landings, occasionally falling.
Rink-side, Professor Richards’s computer displayed an outline of Ms. Phibbs, construed from the reflective stickers.
“Her left arm is higher than her right arm — she’s got to lean to one side to compensate,” he said. Breathless from jumping, Ms. Phibbs reviewed the computer images.
“With my elbow and my trunk being off, my landing will be off and I’ll two-foot it,” she said. Then Tom Kepple, a researcher, displayed an animated avatar of Ms. Phibbs’s jump attempts, calculating that she rotated only 314 degrees. With a few keystrokes, he tucked the left arm in.
“That adds 40 degrees more of revolution,” he said. “If she brought the left leg in a little straighter? You pick up 10 or 15 degrees rotation. But if she brings her leg in too much, the jump goes bad.”
Such analysis works “not just for technique, but also for injury prevention,” Mr. Moyer said. “You can see what your result is going to be before you try it.” That could make a difference for skaters who must train aggressively enough to master moves but not aggressively enough to hurt themselves.
“I always tell my athletes that they’re going to be injured at some point in their career, so it’s more about management of that and also trying to have a minor injury instead of a major injury,” said Tom Zakrajsek, who coaches top skaters. “I have certain jump limitations and restrictions — I always have to pull back my skaters from repetition of jumping.”
In Delaware, after the scientists opined on Ms. Phibbs’s body position, she got back on the ice.
“I focused on keeping my elbow down, and my landings were a lot more solid,” she said. “It definitely proved itself.”
* By PAM BELLUCK, NEWARK, Del. —June 23, 2009
Researchers get help from a venerable number theory and a popular puzzle game to solve genetic medical mysteries 
A 2,000-year-old math theorem, along with Sudoku, may soon help researchers untangle DNA at blazing speeds.Hunting for a particular genetic mutation in hundreds of thousands of specimens can be an expensive and time-consuming process. In the past several years, faster multiplex DNA sequencing machines have sped up the acquisition of data, but researchers have still been hobbled by having to label each sample with a unique molecular identifier (or bar code) for analysis.Scientists at Cold Spring Harbor Laboratory (CSHL) in Long Island, N.Y., are proposing a new take on a very old idea to tackle large data sets simultaneously. The team is applying the Chinese remainder theorem to pinpoint single samples in larger pools, which are arranged in rows and columns.Invented about 2,000 years ago, the theorem is a method for mapping information using prime and co-prime numbers. In the case of DNA sequencing and Sudoku, the theorem is used to organize data points with coordinates in a box, but it can also be used to figure out all sorts of missing information in other domains, such as distant points sensed with high-speed radar, pieces of code, and who that attractive person was that you saw at three out of seven parties on a cruise ship.By using the idea, researchers can deal with whole libraries of genetic information instead of looking at just "one genetic sequence at a time," says Yaniv Erlich, the lead author of the paper, published as the cover story of this month's Genome Research.In Sudoku players must fill every row and column each with all nine numerals, but in applying this to so many genetic samples to search, the researchers call on state-of-the-art robots, machines and programs to do the specimen placing and searching for them. "Every cell in a Sudoku [puzzle] is like a specimen, and every digit is like a genotype," says Erlich, a doctoral student who had used the Chinese remainder theorem in previous work with radar. He brought the idea to the attention of his CSHL professor Greg Hannon.The process allows researchers to pool dozens of samples and assign the pool—rather than individual samples—with a bar-code identifier. After the sequencing machine returns results from a whole pool, a decoder program can use the theorem to work backward and locate a particular specimen. To find a mutation in a cystic fibrosis study, for example, the decoding program would use each pool's results as the constraints to pinpoint the location of the mutated specimen."Think about Sudoku as a pooling theory," he says. "You have a constraint in a row and column [to] have all nine digits. We have the same thing—maybe not as neat—but we have all the sequences in the same pool." From there, he explains, a program can go back and use the same logic to find the mutant DNA.In the future, sequencing and analysis that would have taken months and $10 million could require just a few days of machine time and $50,000 to $80,000, the study authors note. All thanks to ancient Chinese number logic and a popular pen-and-paper puzzle game—which Erlich now plays regularly.By Katherine Harmon (june 2009)
Scientists are turning agricultural leftovers, wood and fast-growing grasses into a huge variety of biofuels—even jet fuel. But before these next-generation biofuels go mainstream, they have to compete with oil at $60 a barrel 
By now it ought to be clear that the U.S. must get off oil. We can no longer afford the dangers that our dependence on petroleum poses for our national security, our economic security or our environmental security. Yet civilization is not about to stop moving, and so we must invent a new way to power the world’s transportation fleet. Cellulosic biofuels—liquid fuels made from inedible parts of plants—offer the most environmentally attractive and technologically feasible near-term alternative to oil.
Biofuels can be made from anything that is, or ever was, a plant. First-generation biofuels derive from edible biomass, primarily corn and soybeans (in the U.S.) and sugarcane (in Brazil). They are the low-hanging fruits in a forest of possible biofuels, given that the technology to convert these feedstocks into fuels already exists (180 refineries currently process corn into ethanol in the U.S.). Yet first-generation biofuels are not a long-term solution. There is simply not enough available farmland to provide more than about 10 percent of developed countries’ liquid-fuel needs with first-generation biofuels. The additional crop demand raises the price of animal feed and thus makes some food items more expensive—though not nearly as much as the media hysteria last year would indicate. And once the total emissions of growing, harvesting and processing corn are factored into the ledger, it becomes clear that first-generation biofuels are not as environmentally friendly as we would like them to be.
Second-generation biofuels made from cellulosic material—colloquially, “grassoline”—can avoid these pitfalls. Grassoline can be made from dozens, if not hundreds, of sources: from wood residues such as sawdust and construction debris, to agricultural residues such as cornstalks and wheat straw, to “energy crops”—fast-growing grasses and woody materials that are grown expressly to serve as feedstocks for grassoline. The feedstocks are cheap (about $10 to $40 per barrel of oil energy equivalent), abundant and do not interfere with food production. Most energy crops can grow on marginal lands that would not otherwise be used as farmland. Some, such as the short-rotation willow coppice, will decontaminate soil that has been polluted with wastewater or heavy metals as it grows.
Huge amounts of cellulosic biomass can be sustainably harvested to produce fuel. According to a study by the U.S. Department of Agriculture and the Department of Energy, the U.S. can produce at least 1.3 billion dry tons of cellulosic biomass every year without decreasing the amount of biomass available for our food, animal feed or exports. This much biomass could produce more than 100 billion gallons of grassoline a year—about half the current annual consumption of gasoline and diesel in the U.S. Similar projections estimate that the global supply of cellulosic biomass has an energy content equivalent to between 34 billion to 160 billion barrels of oil a year, numbers that exceed the world’s current annual consumption of 30 billion barrels of oil. Cellulosic biomass can also be converted to any type of fuel—ethanol, ordinary gasoline, diesel, even jet fuel.Scientists are still much better at fermenting corn kernels than they are at breaking down tough stalks of cellulose, but they have recently enjoyed an explosion of progress. Powerful tools such as quantum-chemical computational models allow chemical engineers to build structures that can control reactions at the atomic level. Research is done with an eye toward quickly scaling conversion technologies up to refinery scales. And although the field is still young, a number of demonstration plants are already online, and the first commercial refineries are scheduled for completion in 2011. The age of grassoline may soon be at hand.
The Energy LockBlame evolution. Nature designed cellulose to give structure to a plant. The material is made out of rigid scaffolds of interlocking molecules that provide support for vertical growth and stubbornly resist biological breakdown. To release the energy inside it, scientists must first untangle the molecular knot that evolution has created.
In general, this process involves first deconstructing the solid biomass into smaller molecules, then refining these products into fuels. Engineers generally classify deconstruction methods by temperature. The low-temperature method (50 to 200 degrees Celsius) produces sugars that can be fermented into ethanol and other fuels in much the same way that corn or sugar crops are now processed. Deconstruction at higher temperatures (300 to 600 degrees C) produces a biocrude, or bio-oil, that can be refined into gasoline or diesel. Extremely high temperature deconstruction (above 700 degrees C) produces gas that can be converted into liquid fuel.So far no one knows which approach will convert the maximum amount of the stored energy into liquid biofuels at the lowest costs. Perhaps different pathways will be needed for different cellulosic biomass materials. High-temperature processing might be best for wood, say, whereas low temperatures might work better for grasses.
Hot FuelThe high-temperature syngas approach is the most technically developed way to generate biofuels. Syngas—a mixture of carbon monoxide and hydrogen—can be made from any carbon-containing material. It is typically transformed into diesel fuel, gasoline or ethanol through a process called Fischer-Tropsch synthesis (FTS), developed by German scientists in the 1920s. During World War II the Third Reich used FTS to create liquid fuel out of Germany’s coal reserves. Most of the major oil companies still have a syngas conversion technology that they may introduce if gasoline becomes prohibitively expensive.
The first step in creating a syngas is called gasification. Biomass is fed into a reactor and heated to temperatures above 700 degrees C. It is then mixed with steam or oxygen to produce a gas containing carbon monoxide, hydrogen gas and tars. The tars must be cleaned out and the gas compressed to 20 to 70 atmospheres of pressure. The compressed syngas then flows over a specially designed catalyst—a solid material that holds the individual reactant molecules and preferentially encourages particular chemical reactions. Syngas conversion catalysts have been developed by the petroleum chemistry primarily for converting natural gas and coal-derived syngas into fuels, but they work just as well for biomass.
Although the technology is well understood, the reactors are expensive. An FTS plant built in Qatar in 2006 to convert natural gas into 34,000 barrels a day of liquid fuels cost $1.6 billion. If a biomass plant were to cost this much, it would have to consume around 5,000 tons of biomass a day, every day, for a period of 15 to 30 years to produce enough fuel to repay the investment. Because significant logistic and economic challenges exist with getting this amount of biomass to a single location, research in syngas technology focuses on ways to reduce the capital costs.
Bio-OilEons of subterranean pressure and heat transformed Cambrian zooplankton and algae into present-day petroleum fields. A similar trick—on a much reduced timescale—could convert cellulosic biomass into a biocrude. In this scenario, a refinery heats up biomass to anywhere from 300 to 600 degrees C in an oxygen-free environment. The heat breaks the biomass down into a charcoal-like solid and the bio-oil, giving off some gas in the process. The bio-oil that is produced by this method is the cheapest liquid biofuel on the market today, perhaps $0.50 per gallon of gasoline energy equivalent (in addition to the cost of the raw biomass).The process can also be carried out in relatively small factories that are close to where biomass is harvested, thus limiting the expense of biomass transport. Unfortunately, this crude is highly acidic, is insoluble with petroleum-based fuels and contains only half the energy content of gasoline. Although you can burn biocrude directly in a diesel engine, you should attempt it only if you no longer have a need for the engine.
Oil refineries could convert this biocrude into a usable fuel, however, and many companies are studying how they could adapt their existing hardware to the task. Some are already producing a different form of green diesel fuel, suggesting that refineries could handle cellulosic biocrude as well. At the moment, the facilities co-feed vegetable oils and animal fats with petroleum oil directly into their refinery. ConocoPhillips recently demonstrated this approach at a refinery in Borger, Tex., creating more than 12,000 gallons of biodiesel a day out of beef fat shipped from a nearby Tyson Foods slaughterhouse.
Researchers are also figuring out ways to carry out the two-stage process using the chemical engineering equivalent of one-pot cooking—converting the solid biomass to oil and then the oil into fuel inside a single reactor. One of us (Huber) and his colleagues are developing an approach called catalytic fast pyrolysis. The “fast” in the name comes from the initial heating—once biomass enters the reactor, it is cooked to 500 degrees C in a second, which breaks down the large molecules into smaller ones. Like eggs in an egg carton, these small molecules are now the perfect size and shape to fit into the surface of a catalyst.
Once ensconced inside the catalyst’s pores, the molecules go through a series of reactions that change them into gasoline—specifically, the high-value aromatic components of gasoline that increase the octane [see box on page 55]. (High-octane fuels allow engines to run at higher internal pressures, which increases efficiency.) The entire process takes just two to 10 seconds. Already the start-up company Anellotech is attempting to scale up this process from the laboratory to the commercial level. It expects to have a commercial facility in operation by 2014.
Sugar SolutionThe route that has attracted most of the public and private investment thus far relies on a more traditional mechanism—unlock the sugars in plants, then ferment these sugars into ethanol or other biofuels. Scientists have studied literally dozens of possible ways to break down the digestion-resistant cellulose and hemicellulose—the fibers that bind cellulose together inside the cells—to their constituent sugars. You can heat the biomass, irradiate it with gamma rays, grind it into a fine slurry, or subject it to high-temperature steam. You can douse it with concentrated acids or bases or bathe it in solvents. You can even genetically engineer microbes that will eat and degrade the cellulose.
Unfortunately, many techniques that work in the lab have no chance of succeeding in commercial practice. To be commercially viable, the pretreatments must generate easily fermentable sugars at high yields and concentrations and be implemented with modest capital costs. They should not use toxic materials or require too much energy input to work. They must also be able to produce grassoline at a price that can compete with gasoline.The most promising approaches involve subjecting the biomass to extremes of pH and temperature. We are developing a strategy that uses ammonia—a strong base—in one of our laboratories (Dale’s). In this ammonia fiber expansion (AFEX) process, cellulosic biomass is cooked at 100 degrees C with concentrated ammonia under pressure. When the pressure is released, the ammonia evaporates and is recycled. Subsequently, enzymes convert 90 percent or more of the treated cellulose and hemicellulose to sugars. The yield is so high in part because the approach minimizes the sugar degradation that often occurs in acidic or high-temperature environments. The AFEX process is “dry to dry”: biomass starts as a mostly dry solid and is left dry after treatment, undiluted with water. It thus can provide large amounts of highly concentrated, high-proof ethanol.AFEX also has the potential to be very inexpensive: a recent economic analysis showed that, assuming biomass can be delivered to the plant for around $50 a ton, AFEX pretreatment, combined with an advanced fermentation process called consolidated bioprocessing, can produce cellulosic ethanol for approximately $1 per gallon of equivalent gasoline energy content, probably selling for less than $2 at the pump.The Cost of ChangeCost, of course, will be the primary determinant of how fast the use of grassoline will grow. Its main competitor is petroleum, and the petroleum industry has been reaping the technological benefits of dedicated research programs for more than a century. Moreover, most petroleum refineries now in use have already paid off their initial capital costs; grassoline refineries will require investments of hundreds of millions of dollars, a cost that will have to be integrated into the price of the fuel it produces through the years.Grassoline, on the other hand, enjoys several major advantages over fuels from petroleum and other petroleum alternatives such as oil sands and liquefied coal. First, the raw feedstocks are far less expensive than raw crude, which should help keep costs down once the industry gets up and running. Grassoline will be domestically produced, with the national security benefits that confers. And it is far better for the environment than any fossil fuel–based alternative.
In addition, new analytical tools and computer-modeling techniques will let researchers build better, more efficient biorefinery operations at a rate that would have been unattainable to petroleum engineers just a decade ago. We are gaining a deeper understanding of the properties of our raw feedstocks and the processes we can use to convert them into fuel at an ever increasing pace. The U.S. government’s support for research into alternative forms of energy should help this process to accelerate even further. The stimulus bill signed into law by President Barack Obama earlier this year contained $800 million in funding for the Department of Energy’s Biomass Program, which will accelerate advanced biofuels research and development and provide funding for commercial-scale biorefinery projects. In addition, the bill contained $6 billion in loan guarantees for “leading edge biofuel projects” that will commence construction by October 2011.
Indeed, if the U.S. maintains its current commitment to biofuels, the logistical and conversion challenges the industry now faces should be readily overcome. Over the next five to 15 years, biomass conversion technologies will move from the laboratory to the market, and the number of vehicles powered by cellulosic biofuels will grow dramatically. This move toward grassoline can fundamentally change the world. It is a move that is now long overdue.
The Fat of the Matter There is a new drive to make fuel off the fat of the land. In April, High Plains Bioenergy opened a biorefinery next to a pork-processing plant in Guymon, Okla. The refinery takes pork fat—an abundant, low-value by-product of the industrial butchering process—and converts it, along with vegetable oil, into biodiesel. The plant is expected to turn 30 million pounds of lard into 30 million gallons of biodiesel a year. In 2010 the High Plains facility will be joined by a plant in Geismar, La., that will be run by Dynamic Fuels, a joint venture between Tyson Foods and energy company Syntroleum. That plant will use the fat from Tyson’s beef, chicken and pork operations to create 75 million gallons of biodiesel and jet fuel annually.
Yet the biodiesel industry has been battered recently, with many plants sitting idle for lack of demand. Low oil prices have made petroleum-based diesel fuel less expensive than biodiesel, which in the U.S. is typically made from soy and vegetable oils. A $1 per gallon federal tax credit for biodiesel has helped soften the blow, but that credit is set to expire at the end of the year. Some manufacturers worry that if the credit disappears, so will their business. Tyson had earlier partnered with ConocoPhillips to produce biodiesel at an existing ConocoPhillips refinery in Borger, Tex. But insecurity about the status of the tax break has put the project on hold.By George W. Huber and Bruce E. Dale (June 2009)
The melting Arctic is releasing vast quantities of methane. How big is this greenhouse threat? What can be done? 
A young scientist with curly, reddish hair tucked beneath a knit cap stepped gingerly onto the three-day-old ice of a remote lake in northeastern Siberia. Coating the black depths like cellophane, the thin film held no promise to bear her weight, but a sudden dunk in the frigid water was a risk she had to take. Searching the lake by rickety rowboat all summer had failed, and any day winter’s first big snow would engulf the region, obscuring the lake’s surface until spring.
She could not afford to wait that long.The woman shivered in her worn, blue down jacket and glanced up at the overcast sky. After one more cautious step, she spotted her quarry: a cluster of platter-size bubbles frozen into the ice. Those pockets of gas, which had risen from thawing permafrost—formerly frozen soil—at the lake’s bottom, were the aim of her doctoral research. Long elusive, they suddenly stood out like white stars against a night sky, though less serenely. With a small pick she cracked the icy skin of one of the bubbles and remained unfazed when it hissed back like a punctured gas pipe. Leaning forward, she apprehensively struck a match just above the broken bubble and flames as high as her head burst skyward. The flammable substance was methane, a greenhouse gas that could cause more global warming than carbon dioxide (CO2).
Today, nearly seven years after igniting that first bubble, Katey Walter finds herself center stage in an environmental drama playing out across the frozen north. Now a 33-year-old assistant professor at her alma mater, the University of Alaska–Fairbanks, Walter was the first to explain the mysterious methane emissions from Arctic lakes. She isn’t shy about touting their significance as a ticking time bomb. In a complete Arctic thaw, these lakes could discharge a whopping 50 billion tons of methane: 10 times the amount already helping to heat the planet.
Whether a total or more moderate release is in store is still anyone’s guess. But pound for pound, methane in the atmosphere traps 25 times more of the sun’s heat than CO2 does. Consequently, even a modest thaw of the perennially frozen soil that lies under these ephemeral lakes and caps the dry land around them could trigger a vicious cycle: warming releases methane and creates lakes, which thaw permafrost and liberate more gas, which intensifies warming, which creates more lakes, and so on. Some Arctic lakes are growing larger, and researchers are eyeing them suspiciously as a reason why global methane concentrations shot up in 2007 and have stayed high ever since. Other signs indicate that permafrost thawing on the Arctic seafloor may be loosening the cap on large pockets of methane stored deeper down.
Walter is sounding the alarm even louder than before because global warming is taking a special toll across the far north. The region is heating up twice as quickly as the rest of the globe, rapidly melting sea ice in the Arctic Ocean as well as the permafrost, which underlies 8.8 million square miles of the Northern Hemisphere. Leading climate models already suggest greenhouse warming as a result of most of the Arctic’s permafrost thawing by 2100—and the estimates do not yet include the potentially vast additional warming imparted by methane bubbling up out of chilly waters. Walter and others are trying to determine just how much methane could be released into the atmosphere, how soon, how aggressively that release would accelerate the earth’s warming and whether anything can be done to temper the escalating threat.
Burps and BelchesScientists know with great certainty how much methane is in the earth’s atmosphere at any given time from sampling its concentration weekly at dozens of sites worldwide. By plugging these measurements into global climate models, they know methane is responsible for a third of the current warming trend. Exactly how much gas comes from where is harder to say, which is why the Arctic lake bubbles were so long overlooked.
Methane is emitted anywhere organic matter ferments—be that a cow’s belly or frozen soil that starts to thaw. Permafrost, which averages 80 feet thick, is chock-full of dead plant and animal matter that has been locked in cold storage for thousands of years. Conventional wisdom long held that permafrost should take thousands of years to melt away, so researchers expected it to play a negligible role in climate change. But recent findings—Walter’s lake discovery in particular—have wrecked that prediction.
Walter’s work revealed that the relatively warm lake bed was indeed thawing the frozen earth directly below it, down several dozen feet. Thawing a block of permafrost is like taking a package of frozen hamburger out of the freezer and leaving it on the kitchen counter. As the meat warms, ravenous microbes consume it, giving off a gas as a by-product. On dry land, microbes convert the dead animal and plant matter primarily into CO2. But in the wet, oxygen-starved depths of a lake, they instead release methane. Walter’s best guess is that researchers have been underestimating methane emissions from Arctic wetlands by as much as 63 percent.
This methane alert, which Walter raised first in her doctoral thesis, captured the attention of the U.S. Council of Graduate Schools, which in 2006 granted her the nation’s most prestigious honor for doctoral dissertations. She credits her discovery to living lakeside from one season to the next. Most scientists tend to be in the field only during the summer, when the bubbling seeps of gas are hard to spot in open water, or in the winter, when the lake is buried under six feet of snow. The same camouflage deterred Walter until that overcast afternoon in October 2002, when she decided to remain lakeside during Siberia’s brief transition from summer to winter. By the spring of 2003 she knew exactly what she needed to do: place her gas traps directly over known seeps. Her results have since riveted attention on how drastically thawing permafrost could speed up global warming.
Trapping the DemonDuring four years of doctoral work, Walter spent 20 months in the Siberian wilderness, often alone or with only one loyal field assistant. She hiked up to eight miles a day across sodden tundra and braved icy waters on several occasions, deliberately as well as accidentally. She knew exactly what she was getting into; as a high school exchange student to Russia nine years earlier, Walter had learned the language and was deeply touched by the harsh conditions of post-Soviet life.
She jumped at the chance to return.Headquarters for much of those four years was the so-called Northeast Science Station, a small outpost in Cherskii, about 90 miles south of the Arctic Ocean. The station’s director, legendary ecologist Sergey Zimov, who had published his suspicions about the role of lake emissions in climate change, helped to define Walter’s straightforward goal: find a way to quantify the methane release and determine what fraction could be attributed to thawing permafrost. Walter’s first challenge was to invent a way to capture the gas. She knew she would eventually need hundreds of contraptions to adequately sample the two large lakes in her study, so her design needed to be simple—and cheap. Walter and her Siberian field assistant spent weeks cobbling together traps in the station’s cramped attic, mostly from recycled trash they found at abandoned Soviet military bases and along dusty dirt roads. For each trap, they secured an inverted plastic bottle to the center of an umbrella-shaped plastic skirt, which was held open by a hoop of wire to funnel bubbles upward. They made 75 of them in all.
During her first excursions, Walter dutifully placed the traps randomly across the lakes’ unfrozen surface, according to standard scientific protocol. “We put a lot of hard work in that, and I was frustrated,” Walter says. “We could see the bubbles, but we weren’t catching much gas.” It wasn’t until she walked out onto the freshly frozen ice for the first time and saw the disparate collections of bubbles that she realized the methane was rising up at discrete points. She made an executive decision, a bit nervously and without the consent of her thesis advisers, to set the traps directly over seeps when the lakes thawed the following spring. So, in 2003, she set about anchoring many of her traps right near the lake bottom—a job that called for a snorkel and wet suit. Locating a seep and setting the necessary tripod of weights and ropes for a single trap required two and a half hours submerged in lake water still gripped by winter chill.
That same spring Walter’s colleague at Fairbanks, Vladimir Romanovsky, whose computer simulations are some of those predicting a dramatic thaw this century, made an unrelated visit to Cherskii and observed Walter swimming in the icy lakes: “She’s a tough girl,” he says simply. By summer Walter found herself in the hospital with pneumonia. “But a couple of months later, and with a good dose of Russian antibiotics, I was back in the lakes,” she recalls. When winter came again, the drill changed from snorkeling to shoveling. For hours at a time Walter dug away at the snow atop the ice, clearing paths above the seeps and marking them with flags as she went. “The Siberians were laughing their heads off at how much money we were spending to come to Siberia to shovel snow off the frozen lakes,” she says. But no one was laughing when the world learned about her hard-won findings.
Proof for a SpikeWalter’s intimate relationship with a handful of Siberian lakes initially brought lake emissions into the limelight, but it was her analysis of their global importance, which she reported in two major scientific journals in 2007, that really turned heads. The potential for emissions to increase dramatically became clear through her work with paleoecologist Mary Edwards of the University of Southampton in England, who has studied the life histories of Arctic lakes. Together they showed that methane bubbling out of Arctic lakes could have been responsible for up to 87 percent of the spike in methane emissions that helped the planet warm from the most recent ice age. At that time, roughly 11,400 years ago, global methane concentrations rose 50 percent in less than 200 years.Many scientists are keen to determine whether such a dramatic spike might happen again. A steady march of global warming, spread out over hundreds or thousands of years, could set off the gaseous Arctic time bomb slowly. But a quicker thaw could ignite a runaway outgassing of methane.
For about a decade it has been clear that the ongoing loss of sea ice is accelerating the Arctic’s rapid warming, says climate modeler David Lawrence of the National Center for Atmospheric Research in Boulder, Colo. When summer ice retreated to a record minimum in 2007 and again last year, the outlook seemed to worsen by the month. New estimates, published in April by the National Oceanic and Atmospheric Administration, predict nearly ice-free summers by 2037—three times sooner than earlier models indicated. The prospect of more open water has nations scrambling to stake oil and gas claims to the Arctic seabed [see “Arctic Landgrab,” by Jessa Gamble; Scientific American Earth 3.0, Vol. 19, No. 1, 2009], but the backlash for climate change could be severe. Dark seawater absorbs more of the sun’s heat than white ice does, thus warming the region’s air and thereby the soil, putting permafrost at risk. Lawrence’s newest global climate simulations predict that warming associated with spells of particularly rapid loss of sea ice could lead directly to faster permafrost thaw.
During such episodes, which would last five or 10 years, autumn temperatures might increase by as much as nine degrees Fahrenheit along Arctic shorelines, and the heat penetrating inland would more than triple the average warming rates previously assumed.Rising inland temperatures are fueling another dramatic change “potentially as profound as the loss of sea ice,” says Matthew Sturm of the U.S. Army’s Cold Regions Research and Engineering Laboratory in Fort Wainwright, Alaska. Shrubs are taking over great swaths of the tundra. During the summer, shrubs absorb more sunlight than does the mossier, grassier vegetation they replace, warming the ground further. And in the winter they create snowdrifts that help the ground hold on to summer heat. Sturm’s extensive comparison of 6,000 aerial photographs taken across northern Alaska for oil exploration during the 1940s to present-day surveys of the same locations shows significant shrub expansion, now covering 77,000 square miles.
Double the EmissionsSome Arctic scientists are quick to point out that certain environmental changes could slow warming rather than speed it up, however. Sturm has also found areas where shrubs are not expanding and soils are colder. In other regions, the conversion of mossy tundra to thin forest, not shrubland, offsets some rise in greenhouse gases by storing more carbon in trees. Still, the consensus is that warming will dominate. “The question is whether this is a weak positive or a strong positive,” Lawrence says. “It may take a long time to get the numbers right.”
Even now, though, Lawrence is willing to offer a lower bound of methane release. It is easy, he says, to envision conditions that double methane emissions from the Arctic by the end of the 21st century simply by activating more microbes in those uppermost few feet of Arctic soil that thaw every summer, the so-called active layer. But more lakes formed because of thawing would send that estimate skyrocketing. Walter’s work suggested that the lakes near Cherskii expanded significantly between 1974 and 2000 and that as they did, they ate into the permafrost along their shorelines. She found that methane rises up most vigorously at these outer edges, which fueled her 2006 estimate that an expansion of thaw lakes increased methane emissions in the region by 58 percent.Going back to Siberia as a professor in 2008 made her wonder if it was time to update that estimate. The banks of the lake where she lit her first methane bubble in 2002 had advanced greatly. “The dramatic changes to my study sites really made my eyebrows go up,” she says. “I couldn’t even recognize the lake margins. Some ponds appeared to have doubled or tripled in size.” If other lakes experienced similar growth they may have contributed to the global methane spike that began two years ago.
Walter still spends four months or more each year walking the lakes in dogged pursuit of answers. Her collaborators and study sites have expanded considerably. To date, she and her colleagues have visited 60 lakes in Siberia and Alaska, but that is still only the tip of the proverbial iceberg. With no hope of visiting every Arctic thaw lake in person, her team is now working on a technique to spot methane seeps from space. One new high-resolution German satellite, TerraSAR-X, is making it possible to identify distinct patches of bubbles on the surfaces of frozen lakes—and to keep track of which patches are growing.
One More Reason to Cut BackOnce a given helping of permafrost starts to thaw and a gas leak starts, not much can be done about it. Local villages could capture the bubbling methane gas and use it to replace diesel fuel (technologies already exist for capturing methane released from landfills). But that is a “very small fix,” Walter concedes. The only real solution is to slow the thaw itself.
Those of us living at lower latitudes can make the greatest difference. The model linking permafrost thaw to loss of sea ice predicts that both processes could be slowed considerably if humanity stabilizes CO2 emissions soon, slowing the atmospheric warming that is generating the methane. “It’s not a runaway train,” Lawrence says. Not yet, anyway, Walter and others warn. Lawrence sounds optimistic when he says, “Perhaps we have to reduce emissions by 80 percent rather than 70 percent by 2050.” But such dramatic reductions won’t be easy. Since 2000 human activities have raised CO2 concentrations much faster than expected.Even if humanity finds the resolve to slow warming, too much thawing in the wrong place could tap submerged caverns of methane. Just below the permafrost layer in many locations lurk large pockets of pure gas that formed millions of years ago. Some of the pockets are run-of-the-mill natural gas reserves, but others are so-called methane hydrates, massive deposits of ice that contain large amounts of gas within their crystalline structure.
Some scientists suspect that permafrost acts as a cap that protects hydrates from melting, particularly in the shallow Arctic seafloor, where the hydrates are found only a few tens of feet deep. The more that sea or lake waters thaw the permafrost below, the more likely this cap is to blow suddenly, releasing jets of methane up through the water and into the atmosphere. A team that included two of Walter’s colleagues at Fairbanks found such plumes rising up from the shallow continental shelf of Siberia in 2008. Possibly, these releases have been happening for a long time, and we are only now noticing them. But the discoverers point out that the Siberian shelf alone holds an estimated 1.4 trillion tons of methane in the form of gas hydrates—equivalent to the newest estimates of the total greenhouse gases that would be released during a complete permafrost thaw.Many researchers note that methane hydrates exist below the permafrost on land as well. The deposits are generally assumed to be too deep to be at risk of thawing. But that assumption, like others before it, has been cast in doubt. If Walter confirms indications from a field excursion earlier this year that Arctic lakes are tapping a methane source even older and greater than permafrost, her alerts would have to be cranked up considerably. And those bubbles she lights would take on an even more sinister glow.
More beasts, less burden: Large animals could help keep permafrost frozen.Strangely enough, one way to slow the thawing of permafrost is to reintroduce massive herds of large, plant-eating animals to the Arctic landscape to mimic the days when millions of mammoths roamed the Siberian steppes. Although the idea may sound like science fiction, it is based in sound ecology. “Snow is like a down jacket that keeps the ground warm,” University of Alaska–Fairbanks researcher Katey Walter points out. “As the activity of animals compresses the snow or removes it through their foraging, the cold winter temperatures can penetrate deeper into the ground and keep the permafrost frozen.” Indeed, ecologist Sergey Zimov, director of the Northeast Science Station in Cherskii, Siberia, has hired local villagers to fashion that solution with their own hands. They have fenced off a 625-square-mile ranch Zimov calls Pleistocene Park and stocked it with moose, reindeer and Yakutian horses. Zimov has mimicked mammoths by driving around a military tank to crush the ground, too. He argues that the climate is still optimal for grassland, which would also insulate the permafrost below, if animals can thrive to cultivate it. Hunting, not climate, he points out, is blamed for the mammoth’s demise.
· By Sarah Simpson (June 2009)
No direct impact caused Paul McQuigg’s brain injury in Iraq three years ago. And no wound from the incident visibly explains why Mr. McQuigg, now an office manager at a California Marine base, can get lost in his own neighborhood or arrive at the grocery store having forgotten why he left home.But his blast injury — concussive brain trauma caused by an explosion’s invisible force waves — is no less real to him than a missing limb is to other veterans. Just how real could become clearer after he dies, when doctors slice up his brain to examine any damage.
Mr. McQuigg, 32, is one of 20 active and retired members of the military who recently agreed to donate their brain tissue upon death so that the effects of blast injuries — which, unlike most concussions, do not involve any direct contact with the head — can be better understood and treated. The research will be conducted by the Sports Legacy Institute, a nonprofit organization based in Waltham, Mass., and by the Boston University Center for the Study of Traumatic Encephalopathy, whose recent examination of the brains of deceased football players has found damage linked to cognitive decline and depression. Whether single, non-impact blasts in battle can cause the same damage as the years of repetitive head bashing seen in football is of particular interest to researchers. The damage, primarily toxic protein deposits and tangled brain fibers, cannot be detected through noninvasive procedures like M.R.I.’s and CT scans.“We don’t know much about the medium- or long-term effects of head trauma experienced by our military,” said Robert Stern, co-director of the Boston University center as well as its Alzheimer’s Disease Clinical and Research Program. “We know that there are some immediate effects in terms of blast injury on cognition and behavior. But we do not yet know whether there are any long-term effects.”“Does that single blow result in something that doesn’t go away,” he added, “or perhaps sets off a cascade of events that leads to a progressive degenerative brain disease?”Mr. McQuigg may be finding out the cruelest way. In February 2006, he was on combat patrol when his Humvee was hit by a roadside bomb, knocking him unconscious, shattering his jaw and damaging his right eye. His helmet could not protect him from a severe concussion that doctors told him was caused solely by the bomb’s force waves, not direct impact.Now he is experiencing headaches, short-term memory problems and trouble with balance that have only worsened.“With prosthetics, you can replace an arm or a leg and can still throw a football with your kid,” said Mr. McQuigg, who works at Camp Pendleton, north of San Diego. “If you have a severe brain injury, you might not be able to live on your own.” “And people don’t know what’s wrong with you,” he added. “People know if you’re missing an arm, something happened. If it happened to your brain, they can’t tell.” An estimated 320,000 soldiers have experienced some form of traumatic brain injury during their service in Iraq or Afghanistan, according to a 2008 RAND Corp. study. Blast injuries have risen in prominence in recent years because improvements in armor and medical treatment allow soldiers to survive explosions, then experience any delayed effects.Blast injuries result from waves of air pressure that can travel several times as fast as hurricane winds. Those waves can not only throw a soldier dozens of feet in the air into other objects — causing a conventional concussion as the brain crashes inside the skull — but may also subject brain tissue to sudden pressure variations that can cause similar damage.
Repeated brain trauma among some football players and boxers has been linked to the subsequent appearance of toxic proteins and neurofibrillary tangles in the brain — a disease known as chronic traumatic encephalopathy, or C.T.E. Many athletes who were found after death to have had the disease experienced memory loss, depression and oncoming dementia as early as their 30s, decades before afflictions like Alzheimer’s appear in the general population.
Just as researchers at the Boston University center and elsewhere have linked some athletes’ later-life emotional problems to their on-field brain trauma, the research on military personnel will try to determine whether some soldiers with post-traumatic stress disorder — a psychological diagnosis — actually retain physical brain damage caused by battlefield blasts. Some signs of P.T.S.D., particularly depression, erratic behavior and the inability to concentrate, appear similar to those experienced by concussed athletes.
Such a link could have effects beyond medicine. Disability benefits for veterans can vary depending on whether an injury is considered psychological or physical. And veterans with P.T.S.D. alone do not receive the Purple Heart, the medal given to soldiers wounded or killed in enemy action, because it is not a physical wound. Dr. Stern, at Boston University, said that blast injuries could be seen as this generation’s version of exposure to Agent Orange, the herbicide used in the Vietnam War.
“During exposure to Agent Orange, it wasn’t known what long-term effects there would be, but through scientific study, long-term study of veterans, those effects have been more clearly understood,” he said. “We need to know if these individuals with blast injuries are going to require long-term care and treatment.”The Boston University center and the Sports Legacy Institute will compare findings from the brains of military personnel with those from their athlete program, which has signed up more than 120 donors in less than a year, and other brain banks around the world. The two centers, not the military, are paying for the registry, storage and examination of brain tissue.
But Col. Michael S. Jaffee, national director of the Defense and Veterans Brain Injury Center, said the Defense Department supported the spirit of the research and could assist in approaching active and retired soldiers to register for brain donation.“Having a brain bank to allow us to study what these brains look like will help us correlate this with other emerging research findings,” said Colonel Jaffee, who is a physician. But he cautioned: “Whenever we’re talking about organ donation for the sake of science, we’re dealing with a lot of sensitive and cultural issues. We ask people to consider and realize that asking family and individuals to remove the brain from the body, many cultures and traditions may not find that acceptable. So it’s always a challenge to balance the benefits, which are real and will come, with a way to maintain the dignity and respect of people who have made the ultimate sacrifice.”
Benefits of the research on military personnel could extend to the general population, said Dr. Daniel P. Perl, director of neuropathology at the Mount Sinai School of Medicine in New York. Even though civilians are rarely subjected to anything close to the devastating waves that burst from battle explosions, the characteristics of blast injuries could lend insight into brain damage caused by single impacts in automobile accidents, for example.
If protein deposits and tangles appear in the hippocampus area of the brain, for instance, then they would affect short-term memory; appearance in the frontal lobes could impair executive function, and in the cerebellum coordination and balance. The researchers will also be looking at possible genetic factors.
“I wouldn’t be surprised if there was a great deal of overlap between examples of this from the sports arena and the military, but we don’t know,” Dr. Perl said. “The forces are different and presumably the mechanisms are somewhat different. If this research and the examinations are done right, they have the potential to contribute significantly. It could tell us what happens, which we’re not going to get otherwise.”
By ALAN SCHWARZ June 23, 2009
"Metal organic frameworks" look like rocks, act like sponges
To capture the carbon dioxide generated by coal plants, chemical companies like Dow Chemical Co. and energy giants like Alstom SA have been betting big on liquid solvents like amine, a corrosive derivative of ammonia that has a thirst for binding with CO2.
Problem is, once the two are bound, they never want to part.In an attempt to circumvent the huge energy demands needed to separate amines from CO2, which can take up to 25 percent of the energy generated by a coal plant, scientists -- many funded by the Department of Energy -- are developing a new generation of porous solids that can trap CO2 and then, almost as easily, let it go.Such solids come in various forms: carbon derived from sugars and tattooed with microscopic holes; molecular sieves that sift and separate chemicals; and elaborate, Tinkertoy-like molecules that form massive skeletons capable of trapping and holding specific chemicals.
At the forefront of this last field is the laboratory of Omar Yaghi at the University of California, Los Angeles, which over the past decade has helped create a new realm of massive, crystalline molecules called metal organic frameworks, or MOFs. With an acronym that sounds like the name of a fuzzy rodent, different species of MOFs may become the basis for hydrogen fuel tanks, drug-delivery devices and CO2 scrubbers.
Now, the lab has created a new generation of MOFs that have close to the same storage capacity and preference for CO2 as amines do, while only weakly bonding with the molecule. The research will be published later this year; the lab's previous reports on the subject have appeared in Science and Nature.
To the naked eye, MOFs look "kind of like a rock," said Bo Wang, a researcher in Yaghi's lab. But at the molecular level, these seeming solids look like a massive series of circular cages, almost like a honeycomb or molecular sponge, he said.Amines, once they have chemically reacted with CO2, must be cooked at 120 degrees Celsius for one to two hours before they let go of their load. According to Wang, it takes two minutes at 60 degrees Celsius for 1 gram of the new MOFs to drop their CO2 and be ready for further use.
The MOFs' secret is that their frameworks -- which are built out of metal ion clusters connected by organic links -- are easily modified. Yaghi's lab has made thousands of different versions of the molecules, testing to see which had the proper shape to selectively admit CO2.
"The genius of the materials that Professor Yaghi has developed is their enormous capacity for CO2," said Joseph Hupp, a chemist at Northwestern University who has developed MOFs that separate CO2 from methane.Carbon dioxide has a moment where its electrons are not distributed evenly among the molecule, called its quadropole moment, Hupp said. This signature is distinctive from many other gases and allows MOFs, through their arrangement of atoms, to be selective.Hupp is uncertain that MOFs will easily be applied to the steamy industrial environment of the coal plant. "I think it's conceivable, but I'm not so sure," he said.
Wang thinks he has a molecule that will be ready to scale up to industrial levels in an affordable way. Already, Yaghi's lab has partnered with the chemical giant BASF SE to mass-produce three simple MOFs, called Basolite, which are used to absorb a wide range of chemicals.Once you have the recipe down, MOFs are simple to assemble, Wang said."It's easy as shake and bake," he said. You have these metals and organic linkers, and you "dump these into the solvent and cook it. And when it cools down you will see crystals. ... It's more like self-assembly."
It remains to be seen if MOFs will be able to compete commercially with liquid solvents, which offer a less complicated chemistry. Wang points out that BASF has already lowered the price of its Basolite line to about €10 per kilogram. "That's already competitive," he said.Takes one to know oneThe Department of Energy is spreading its bets on porous solids and recently announced funding support of $2 million for a research project at TDA Research Inc., a private firm based in Wheat Ridge, Colo., in the shadow of the National Renewable Energy Laboratory.
TDA has proposed using a proprietary form of activated carbon for capturing CO2. Typically, activated carbon, which is hugely porous -- 1 gram contains almost the surface area of a basketball court -- is used to absorb poisons and in groundwater remediation or sewage treatment.The carbon developed by Steven Dietz, a researcher at TDA, has two different sizes of pores, which he calls mesopores and micropores. The larger mesopores act as channels to the micropores, greatly increasing the rate at which TDA's carbon absorbs CO2, compared to activated carbon.
Most activated carbon is derived from "carbonized" -- or burnt up -- plants like coconut shells, which still limits one to the plant's structure, Dietz said. TDA can now develop activated carbon from sugars, which means there is less junk floating around the compound. It is essentially synthetic.Dietz at first wanted to use the carbon for ultracapacitors, which quickly soak up electricity. Then he noticed how basic his mesocarbon was, meaning it could be perfect for soaking up acidic carbon dioxide. So last fall, he wandered down the hall to Gokhan Alptekin, a TDA engineer, and they did a few lab experiments and said, "Yeah, these look interesting."Research into many other solid adsorbents is under way -- some possibly closer to industrial use than MOFs or TDA's carbon -- and all share the challenge of working in the harsh environment of the coal plant, said Timothy Fout, a project manager at DOE's National Energy Technology Laboratory."The types of experiments and setups that are used in the laboratory to determine reaction rates and particle properties often do not translate directly into large-scale equipment," he said.
This scale-up is easier with liquids, which explains much of the attraction of amines and Selexol, a solvent that will likely be used to capture CO2 in coal plants designed from the ground up for carbon capture. DOE estimates that the cost of electricity produced from plants using Selexol will increase by 30 percent.In the future, the agency hopes technologies like solid adsorbents will replace liquid solvents. But neither Wang nor Dietz is so bold as to think their solids provide the only way forward."But it could be an alternative," Wang said.* By Paul Voosen (june 2009)
(Phenomenal: An enormous dust cyclone swirls over northeastern China)
(Full circle: Asian dust usually deposits near Japan but this cloud dropped the dust on its second tour of the Pacific, as pictured here)
