Sound From Exploding Volcanoes Compared With Jet Engines

Scripps researchers installed an array of microbarometers at Mount St. Helens in November 2004 to collect infrasound near the site

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New research on infrasound from volcanic eruptions shows an unexpected connection with jet engines. Researchers at Scripps Institution of Oceanography at UC San Diego speeded up the recorded sounds from two volcanoes and uncovered a noise very similar to typical jet engines.

These new research findings provide scientists with a more useful probe of the inner workings of volcanic eruptions. Infrasound is sound that is lower in frequency than 20 cycles per second, below the limit of human hearing.
The study led by Robin Matoza, a graduate student at Scripps Oceanography, will be published in an upcoming issue of the journal Geophysical Research Letters, a publication of the American Geophysical Union (AGU). Matoza measured infrasonic sound from Mount St. Helens in Washington State and Tungurahua volcano in Ecuador, both of which are highly active volcanoes close to large population centers.
"We hypothesized that these very large natural volcanic jets were making very low frequency jet noise," said Matoza, who conducts research in the Scripps Laboratory for Atmospheric Acoustics.
Using 100-meter aperture arrays of microbarometers, similar to weather barometers but sensitive to smaller changes in atmospheric pressure and low-frequency infrasonic microphones, the research team tested the hypothesis, revealing the physics of how the large-amplitude signals from eruptions are produced. Jet noise is generated by the turbulent flow of air out of a jet engine. Matoza and colleagues recorded these very large-amplitude infrasonic signals during the times when ash-laden gas was being ejected from the volcano. The study concluded that these large-scale volcanic jets are producing sound in a similar way to smaller-scale man-made jets.
"We can draw on this area of research to speed up our own study of volcanoes for both basic research interests, to provide a deeper understanding of eruptions, and for practical purposes, to determine which eruptions are likely ash-free and therefore less of a threat and which are loaded with ash," said Michael Hedlin, director of Scripps' Atmospheric Acoustics Lab and a co-author on the paper.
Large-amplitude infrasonic signals from volcanic eruptions are currently used in a prototype real-time warning system that informs the Volcanic Ash Advisory Center (VAAC) when large infrasonic signals have come from erupting volcanoes. Researchers hope this new information can improve hazard mitigation and inform pilots and the aviation industry.
"The more quantitative we can get about how the sound is produced the more information we can provide to the VAAC," said Matoza. "Eventually it could be possible to provide detailed information such as the size or flow rate of the volcanic jet to put into ash-dispersal forecasting models."
The paper's co-authors include D. Fee and M A. Garcés, Infrasound Laboratory at the University of Hawaii at Manoa; J.M. Seiner of the National Center for Physical Acoustics at the University of Mississippi; and P.A. Ramón of Instituto Geofisico, Escuela Politecnica Naional. The research study was funded by a National Science Foundation grant.
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Adapted from materials provided by University of California - San Diego.

Rocket Launches May Need Regulation To Prevent Ozone Depletion, Says Study

A Delta rocket launches from NASA's Kennedy Space Center carrying Mars Phoenix lander in 2007.

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The global market for rocket launches may require more stringent regulation in order to prevent significant damage to Earth's stratospheric ozone layer in the decades to come, according to a new study by researchers in California and Colorado.

Future ozone losses from unregulated rocket launches will eventually exceed ozone losses due to chlorofluorocarbons, or CFCs, which stimulated the 1987 Montreal Protocol banning ozone-depleting chemicals, said Martin Ross, chief study author from The Aerospace Corporation in Los Angeles. The study, which includes the University of Colorado at Boulder and Embry-Riddle Aeronautical University, provides a market analysis for estimating future ozone layer depletion based on the expected growth of the space industry and known impacts of rocket launches.
"As the rocket launch market grows, so will ozone-destroying rocket emissions," said Professor Darin Toohey of CU-Boulder's atmospheric and oceanic sciences department. "If left unregulated, rocket launches by the year 2050 could result in more ozone destruction than was ever realized by CFCs."
A paper on the subject by Ross and Manfred Peinemann of The Aerospace Corporation, CU-Boulder's Toohey and Embry-Riddle Aeronautical University's Patrick Ross appeared online in March in the journal Astropolitics.
Since some proposed space efforts would require frequent launches of large rockets over extended periods, the new study was designed to bring attention to the issue in hopes of sparking additional research, said Ross. "In the policy world uncertainty often leads to unnecessary regulation," he said. "We are suggesting this could be avoided with a more robust understanding of how rockets affect the ozone layer."
Current global rocket launches deplete the ozone layer by no more than a few hundredths of 1 percent annually, said Toohey. But as the space industry grows and other ozone-depleting chemicals decline in the Earth's stratosphere, the issue of ozone depletion from rocket launches is expected to move to the forefront.
Today, just a handful of NASA space shuttle launches release more ozone-depleting substances in the stratosphere than the entire annual use of CFC-based medical inhalers used to treat asthma and other diseases in the United States and which are now banned, said Toohey. "The Montreal Protocol has left out the space industry, which could have been included."
Highly reactive trace-gas molecules known as radicals dominate stratospheric ozone destruction, and a single radical in the stratosphere can destroy up to 10,000 ozone molecules before being deactivated and removed from the stratosphere. Microscopic particles, including soot and aluminum oxide particles emitted by rocket engines, provide chemically active surface areas that increase the rate such radicals "leak" from their reservoirs and contribute to ozone destruction, said Toohey.
In addition, every type of rocket engine causes some ozone loss, and rocket combustion products are the only human sources of ozone-destroying compounds injected directly into the middle and upper stratosphere where the ozone layer resides, he said.
Although U.S. science agencies spent millions of dollars to assess the ozone loss potential from a hypothetical fleet of 500 supersonic aircraft -- a fleet that never materialized -- much less research has been done to understand the potential range of effects the existing global fleet of rockets might have on the ozone layer, said Ross.
Since 1987 CFCs have been banned from use in aerosol cans, freezer refrigerants and air conditioners. Many scientists expect the stratospheric ozone layer -- which absorbs more than 90 percent of harmful ultraviolet radiation that can harm humans and ecosystems -- to return to levels that existed prior to the use of ozone-depleting chemicals by the year 2040.
Rockets around the world use a variety of propellants, including solids, liquids and hybrids. Ross said while little is currently known about how they compare to each other with respect to the ozone loss they cause, new studies are needed to provide the parameters required to guide possible regulation of both commercial and government rocket launches in the future.
"Twenty years may seem like a long way off, but space system development often takes a decade or longer and involves large capital investments," said Ross. "We want to reduce the risk that unpredictable and more strict ozone regulations would be a hindrance to space access by measuring and modeling exactly how different rocket types affect the ozone layer."
The research team is optimistic that a solution to the problem exists. "We have the resources, we have the expertise, and we now have the regulatory history to address this issue in a very powerful way," said Toohey. "I am optimistic that we are going to solve this problem, but we are not going to solve it by doing nothing."
The research was funded by the National Science Foundation, NASA and The Aerospace Corporation.
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Adapted from materials provided by University of Colorado at Boulder.

Ice Storms Devastating To Pecan Orchards

This is the aftermath of an ice storm in a pecan grove near Eufaula, Okla.

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Ice storms and other severe weather can have devastating impacts on agricultural crops, including perennial tree crops. Major ice storms occur at least once a decade, with truly catastrophic "icing events" recorded once or twice a century within a broad belt extending from eastern Texas through New England. Ice storms can result in overwhelming losses to orchards and expensive cleanup for producers.
Because the long limbs of pecan trees act as levers and increase the likelihood of breakage, pecan orchards and groves are particularly susceptible to damage from tornadoes, hurricanes, and ice storms. Ice damage is typically more severe in pecan orchards than other orchard crops.

Oklahoma has 85,740 acres of pecans on 2,879 farms. Ice storms struck Oklahoma four times from 2000 through 2007. The crippling ice storm in December 2000, which hit the southeast quarter of Oklahoma, extended into parts of Texas, Louisiana, and Arkansas. An estimated 25,000 to 30,000 acres of pecans were damaged in Oklahoma during this storm alone.
Michael W. Smith from the Department of Horticulture and Landscape Architecture at Oklahoma State University, and Charles T. Rohla of the Samuel Roberts Noble Foundation published a research report in the latest issue of HortTechnology that provides pecan producers, government agencies, and insurance companies with important information concerning orchard management and economics following destructive ice storms.
Cleanup of pecan orchards following ice damage presents enormous challenges for producers. Typical damage, cleanup, and recovery from four ice storms that hit the region from 2000 to 2007 were reported in the study. Trees less than 15 feet tall typically had the least damage; trees 15 to 30 feet tall incurred as much or more damage than larger trees and cleanup costs were greater.
The silver lining: pecan trees are resilient. Most trees can survive and eventually return to productivity following loss of most of their crown. But cleanup costs to ice-damaged pecan orchards are high, ranging from $207 to $419 per acre based on the dollar value in 2008. According to the researchers, these costs were consistent among orchards where the owner supervised the labor and had the resources to obtain equipment necessary to prune and remove debris from the orchard. The cleanup costs paid to "custom operators" for renovating orchards following ice storms were significantly more expensive, ranging from $500 to $800 per acre in 2008 for orchards with similar damage levels.
Explaining the outcomes of the research study, Smith stated; "Following damaging weather events, producers seek information concerning effective cleanup procedures, subsequent management, recovery duration, and economic impact. State and Federal agencies and insurance companies seek guidance concerning economic impact and how to assist producers. Our objective was to provide information for producers and others regarding the impact of an ice storm on pecans."
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Adapted from materials provided by American Society for Horticultural Science, via EurekAlert!, a service of AAAS.

Hollow Gold Nanospheres Show Promise For Biomedical And Other Applications

Partial view of a gold nanosphere (shown), magnified by a factor of one billion, as seen through an electron microscope. The darker ring shows the "wall" of the nanosphere, while the lighter area to the right of the ring shows the interior region of the shell.

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A new metal nanostructure developed by researchers at the University of California, Santa Cruz, has already shown promise in cancer therapy studies and could be used for chemical and biological sensors and other applications as well.
The hollow gold nanospheres developed in the laboratory of Jin Zhang, a professor of chemistry and biochemistry at UCSC, have a unique set of properties, including strong, narrow, and tunable absorption of light. Zhang is collaborating with researchers at the University of Texas M. D. Anderson Cancer Center, who have used the new nanostructures to target tumors for photothermal cancer therapy. They reported good results from preclinical studies earlier this year (Clinical Cancer Research, February 1, 2009).

Zhang will describe his lab's work on the hollow gold nanospheres in a talk on Sunday, March 22, at the annual meeting of the American Chemical Society in Salt Lake City.
"What makes this structure special is the combination of the spherical shape, the small size, and the strong absorption in visible and near infrared light," Zhang said. "The absorption is not only strong, it is also narrow and tunable. All of these properties are important for cancer treatment."
Zhang's lab is able to control the synthesis of the hollow gold nanospheres to produce particles with consistent size and optical properties. The hollow particles can be made in sizes ranging from 20 to 70 nanometers in diameter, which is an ideal range for biological applications that require particles to be incorporated into living cells. The optical properties can be tuned by varying the particle size and wall thickness.
In the cancer studies, led by Chun Li of the M. D. Anderson Cancer Center, researchers attached a short peptide to the nanospheres that enabled the particles to bind to tumor cells. After injecting the nanospheres into mice with melanoma, the researchers irradiated the animals' tumors with near-infrared light from a laser, heating the gold nanospheres and selectively killing the cancer cells to which the particles were bound.
Cancer therapy was not the goal, however, when Zhang's lab began working several years ago on the synthesis and characterization of hollow gold nanospheres. Zhang has studied a wide range of metal nanostructures to optimize their properties for surface-enhanced Raman scattering (SERS). SERS is a powerful optical technique that can be used for sensitive detection of biological molecules and other applications.
Adam Schwartzberg, then a graduate student in Zhang's lab at UCSC, initially set out to reproduce work reported by Chinese researchers in 2005. In the process, he perfected the synthesis of the hollow gold nanospheres, then demonstrated and characterized their SERS activity.
"This process is able to produce SERS-active nanoparticles that are significantly smaller than traditional nanoparticle structures used for SERS, providing a sensor element that can be more easily incorporated into cells for localized intracellular measurements," Schwartzberg, now at UC Berkeley, reported in a 2006 paper published in Analytical Chemistry.
The collaboration with Li began when Zhang heard him speak at a conference about using solid nanoparticles for photothermal cancer therapy. Zhang immediately saw the advantages of the hollow gold nanospheres for this technique. Li uses near-infrared light in the procedure because it provides good tissue penetration. But the solid gold nanoparticles he was using do not absorb near-infrared light efficiently. Zhang told Li he could synthesize hollow gold nanospheres that absorb light most efficiently at precisely the wavelength (800 nanometers) emitted by Li's near-infrared laser.
"The heat that kills the cancer cells depends on light absorption by the metal nanoparticles, so more efficient absorption of the light is better," Zhang said. "The hollow gold nanospheres were 50 times more effective than solid gold nanoparticles for light absorption in the near-infrared."
Zhang's group has been exploring other nanostructures that can be synthesized using the same techniques. For example, graduate student Tammy Olson has designed hollow double-nanoshell structures of gold and silver, which show enhanced SERS activities compared to the hollow gold nanospheres.
The ability to tune the optical properties of the hollow nanospheres makes them highly versatile, Zhang said. "It is a unique structure that offers true advantages over other nanostructures, so it has a lot of potential," he said.
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Adapted from materials provided by University of California - Santa Cruz, via EurekAlert!, a service of AAAS.

Inactivity Of Proteins Behind Longer Shelf Life When Freezing

Frozen biological material, for example food, can be kept for a long time without perishing. A new study is close to providing answers as to why.

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Frozen biological material, for example food, can be kept for a long time without perishing. A study by researchers at the University of Gothenburg, Sweden, is close to providing answers as to why.
A cell's proteins are programmed to carry out various biological functions. The protein's level of activity and its ability to successfully carry out these functions is dependent on the amount of water by which it is surrounded. For example, dry proteins are completely inactive. A critical amount of water is required in order for the function to get going, after which point the protein's level of activity increases concurrently with an increase in the amount of water. Proteins achieve full biological activity when the surrounding water has approximately the same weight as the protein.

Researchers at the University of Gothenburg and Chalmers University of Technology have together with a group of American researchers used advanced experimental techniques to study how movements in the water that surrounds the protein cause movements in the protein itself. The study, which is being published in the journal PNAS, indicates that the dynamics in the surrounding water have a direct effect on the protein's dynamics, which, in turn, should affect the activity.
The results explain, for example, why biological material such as foodstuffs or research material can be stored at low temperatures for a long period of time without perishing.
"When the global movements in the surrounding water freeze, then significant movements within the protein also come to a stop. This results in the protein being preserved in a state of minimum energy and biological activity comes to a stop," says researcher Helén Jansson at the Swedish NMR Centre, University of Gothenburg, Sweden.
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Adapted from materials provided by University of Gothenburg.

Rising Sea Levels Set To Have Major Impacts Around The World

Houses along the Mexican Riveria in Cabo San Lucas. The impacts of sea level rise - even in the lower ranges of the current predictions - looks to be severe. Approximately ten percent of the worlds population - 600 million people - live in low lying areas in danger of being flooded.

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Research presented March 10 at the International Scientific Congress on Climate Change in Copenhagen shows that the upper range of sea level rise by 2100 could be in the range of about one meter, or possibly more. In the lower end of the spectrum it looks increasingly unlikely that sea level rise will be much less than 50 cm by 2100.
This means that if emissions of greenhouse gases is not reduced quickly and substantially, even the best case scenario will hit low lying coastal areas housing one in ten humans on the planet hard.
Dr John Church of the Centre for Australian Weather and Climate Research, Hobart, Tasmania, Australia and the lead speaker in the sea level session, told the conference, "The most recent satellite and ground based observations show that sea-level rise is continuing to rise at 3 mm/yr or more since 1993, a rate well above the 20th century average. The oceans are continuing to warm and expand, the melting of mountain glacier has increased and the ice sheets of Greenland and Antarctica are also contributing to sea level rise."

New insights reported include the loss of ice from the Antarctic and Greenland Ice Sheets. "The ice loss in Greenland has accelerated over the last decade. The upper range of sea level rise by 2100 might be above 1m or more on a global average, with large regional differences depending where the source of ice loss occurs", says Konrad Steffen, Director of the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado, Boulder and co-chair of the congress session on sea level rise.
The last assessment report from the IPCC from 2007 projected a sea level rise of 18 - 59 centimeter. However the report also clearly stated that not all factors contributing to sea level rise could be calculated at that time. The uncertainty was centered on the ice sheets, how they react to the effects of a warmer climate and how they interact with the oceans, explains Eric Rignot, Professor of Earth System Science at the University of California Irvine and Senior Research Scientist at NASA's Jet Propulsion Laboratory.
"The numbers from the last IPCC are a lower bound because it was recognized at the time that there was a lot of uncertainty about ice sheets. The numerical models used at the time did not have a complete representation of outlet glaciers and their interactions with the ocean. The results gathered in the last 2-3 years show that these are fundamental aspects that cannot be overlooked. As a result of the acceleration of outlet glaciers over large regions, the ice sheets in Greenland and Antarctica are already contributing more and faster to sea level rise than anticipated. If this trend continues, we are likely to witness sea level rise one meter or more by year 2100", he says.
"Unless we undertake urgent and significant mitigation actions, the climate could cross a threshold during the 21st century committing the world to a sea level rise of metres", said John Church.
"Measurements around the world show that sea level has risen almost 20 centimeters since 1880," explains Professor Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research, who will give the plenary speech on sea level rise at the congress. These data also reveal that the rate of sea level rise is closely linked to temperature: sea level rises faster the warmer it gets. "If sea level keeps rising at a constant pace, we will end up in the middle of that 18-59 cm IPCC range by 2100," says Rahmstorf. "But based on past experience I expect that sea level rise will accelerate as the planet gets hotter."
The impacts of sea level rise - even in the lower ranges of the current predictions - looks to be severe. Approximately ten percent of the worlds population - 600 million people - live in low lying areas in danger of being flooded. A previously released study led by John Church, shows that even a modest sea level rise of 50 centimeters will result in a major increase in the number of coastal flooding events.
"Our study centered on Australia showed that coastal flooding events that today we expect only once every hundred years will happen several times a year by 2100", says John Church.
John Church also brings new results of the current sea level rise to the congress, "Sea level is currently rising at a rate that is above any of the model projections of 18 to 59 cm".
"Different groups may come to slightly different projections, but differences in the details of the projections should not cloud the overall picture where even the lower end of the projections looks to have very serious effects," says Konrad Steffen.

1. The rising tide: assessing the risks od climate change and human settlements in low elevation costal zones. Gordon McGranahan, Deborah Balk, and Bridget Anderson; Environment and Urbanization, Apr 2007; vol. 19: pp. 17-37.
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Adapted from materials provided by University of Copenhagen.

40-year Mystery Revisited: Newtonian System Mimics 'Baldness' Of Rotating Black Holes

Clifford Will hopes to learn more about how small black holes orbit around rotating massive black holes in general relativity, where the relativistic Carter constant plays a key role.

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The rotating black hole has been described as one of nature's most perfect objects. As described by the Kerr solution of Einstein's gravitational field equations, its spacetime geometry is completely characterized by only two numbers — mass and spin — and is sometimes described by the aphorism "black holes have no hair.''
A particle orbiting a rotating black hole always conserves its energy and angular momentum, but otherwise traces a complicated twisting rosette pattern with no discernible regularity.
But in 1968, theoretical physicist and cosmologist Brandon Carter showed that the particle's wild gyrations nevertheless hold another variable fixed, which was named the "Carter constant.'' The true meaning of Carter's constant still remains somewhat mysterious 40 years after its discovery.

Now Clifford M. Will, Ph.D., the James S. McDonnell Professor of Physics in Arts & Sciences at Washington University in St. Louis, has shown that, even in Newton's theory of gravitation, arrangements of masses exist whose gravitational field also admits a Carter-like constant of motion, in addition to energy and angular momentum.
What's more, the deviation of the field's shape from being spherical is determined by a set of equations that are identical to those for Kerr black holes.
In his article "Carter-like Constants of the Motion in Newtonian Gravity and Electrodynamics" in the Feb. 12 issue of Physical Review Letters, Will points out that one Newtonian system that exhibits this property is surprisingly simple: two equal point masses at rest separated by a fixed distance.
"I was completely stunned when I saw that the Newtonian condition for a Carter constant was identical to the condition imposed by the black hole no-hair theorems," said Will. "Do I know why this happens? So far, not a clue.
"But what I really hope is that insights gained about this strange constant in the simpler Newtonian context will teach us something about how small black holes orbit around rotating massive black holes in general relativity, where the relativistic Carter constant plays a key role."
This will have implications for gravitational-wave astronomy, he says, because the signal from such events may be detectable by the advanced LIGO-VIRGO-GEO network of ground-based laser interferometric detectors or by the proposed space-based LISA (Laser Interferometer Space Antenna).
Will, who is also a visiting associate at the Institute of Astrophysics in Paris, is a theoretical physicist whose research interests encompass the observational and astrophysical implications of Einstein's general theory of relativity, including gravitational radiation, black holes, cosmology, the physics of curved spacetime and the interpretation of experimental tests of general relativity.
Will's "Was Einstein Right?" (1986) won the American Institute of Physics Science Writing Award. His "Theory and Experiment in Gravitational Physics" (1981) is considered the bible of the field.
His research was supported in part by the National Science Foundation, the National Aeronautics and Space Administration and the Centre National de la Recherche Scientifique, Programme Internationale de la Cooperation Scientifique.
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Adapted from materials provided by Washington University in St. Louis.

Nanoparticles Double Their Chances Of Getting Into Sticky Situations, And Boost Potential Uses

Stefan Bon (left) David Cheung right with image from their paper.

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Chemistry researchers at the University of Warwick have found that tiny nanoparticles could be twice as likely to stick to the interface of two non mixing liquids than previously believed. This opens up a range of new possibilities for the uses of nanoparticles in living cells, polymer composites, and high-tech foams, gels, and paints. The researchers are also working on ways of further artificially enhancing this new found sticking power.
University of Warwick researchers reviewed molecular simulations of the interaction between a non-charged nanoparticle and an "ideal" liquid-liquid interface. They were surprised to find that very small nanoparticles (of around 1 to 2 nanometres) varied considerably in their simulated ability to stick to such interfaces from what was expected in the standard model.

The researchers found that it took up to 50 percent more energy to dislodge the particles from the liquid-liquid interface for the smallest particle sizes. However as the radius of the particles increased this deviation from the standard model gradually faded out.
The researchers, Dr ir Stefan A. F. Bon and Dr David L. Cheung, believe that previous models failed to take into account the action of "capillary waves" in their depiction of the nanoparticles behaviour at the liquid to liquid interfaces.
Dr ir Stefan A. F. Bon said, " This new understanding on the nano-scale gives us much more flexibility in the design of everything from high-tech composite materials, to the use of quantum dots, cell biochemistry, and the manufacture of new "armored" polymer paint particles."

The researchers are now working on ways to build on this newly found natural stickiness of nanoparticles by designing polymer nanoparticles with opposing hydrophobic and hydrophilic surfaces that will bind even more strongly at oil/water liquid interfaces.
The research was funded by the Engineering and Physical Sciences Research Council (EPSRC)

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Adapted from materials provided by University of Warwick.

James Webb Space Telescope's Actual 'Spine' Now Being Built

Scientists and engineers at Northrop Grumman work with the Backplane Structure Test Article" (BSTA) or "spine" of the Webb Telescope. The BSTA is only 1/6 the size of the backplane that will fly on the telescope.

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Scientists and engineers who have been working on the James Webb Space Telescope mission for years are getting very excited, because some of the actual pieces that will fly aboard the Webb telescope are now being built. One of the pieces, called the Backplane, is like a "spine" to the telescope. The Backplane is now being assembled by Alliant Techsystems at its Magna, Utah facility.
The Webb telescope stands as big as a two-story house, and the Backplane is a core part of the design as it will support the telescope’s 21-foot diameter (6.5 meter) primary mirror. Not only will the Backplane be carrying a large mirror, but it will be supporting a lot of weight. It will be carrying 7,500 lbs (2400 kg) of telescope optics and instruments during space launch to the telescope’s operational position 990,000 miles (1,584,000 km) from Earth.
"The Webb telescope’s ultimate ability to discover the first stars and galaxies is critically dependent on the mirror backplane performing to fantastically demanding standards," said Eric Smith, Webb Telescope program scientist at NASA Headquarters, Washington.

Being the "spine" of the mirror requires it to essentially be motionless while the mirrors move to see far into deep space. Imagine holding the handle of a magnifying glass to see a tiny object. If your hand shakes a lot, it will be hard to focus on the object. So, just as you have to hold the magnifying glass handle steady with your hand, the Webb backplane has to hold the telescope mirrors steady, to allow them to focus.
This structure is also designed to provide unprecedented thermal stability performance at temperatures colder than -400°F (-240°C). That means it is engineered to move less than 32 nanometers, which is 1/10,000 the diameter of a human hair in the extreme cold of space.
Alliant Techsystems' (ATK’s) Backplane represents an improvement in dimensional stability performance of 1000-times, a threefold increase in size, and operational capability at temperatures far colder than any prior space telescope.
The Backplane is made with advanced graphite composite materials mated to titanium and invar fittings and interfaces. Invar is a nickel steel alloy notable for its uniquely low changes due to thermal expansion. It will be completed and delivered to Northrop Grumman in late 2010 for integration into the Webb telescope.
The James Webb Space Telescope is expected to launch in 2013. By observing in infrared light, it will be able to see faint and very distant objects, explore distant galaxies, formation of star systems, and nearby planets and stars. Webb will be able to see "back in time" to the first light after the Big Bang. The information it will send back to Earth will give scientists clues about the formation of the universe and the evolution of our own solar system.

ATK is an aerospace and defense company under contract to Northrop Grumman Aerospace Systems for the engineering, design, fabrication, and testing of the Webb telescope’s composite components and subsystems. ATK is a key partner with Northrop Grumman.
NASA's Goddard Space Flight Center in Greenbelt, Md. is managing the overall development effort for the Webb telescope. The telescope is a joint project of NASA and many U.S. partners, the European Space Agency and the Canadian Space Agency.
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Adapted from materials provided by NASA.

Ice Declining Faster Than Expected In Both Arctic And Antarctic Glaciers

Polar bear mother with two cubs on sea ice.

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Multidisciplinary research from the International Polar Year (IPY) 2007-2008 provides new evidence of the widespread effects of global warming in the polar regions. Snow and ice are declining in both polar regions, affecting human livelihoods as well as local plant and animal life in the Arctic, as well as global ocean and atmospheric circulation and sea level.
These are but a few findings reported in “State of Polar Research”, released February 25 by the World Meteorological Organization (WMO) and the International Council for Science (ICSU). In addition to lending insight into climate change, IPY has aided our understanding of pollutant transport, species’ evolution, and storm formation, among many other areas.

The wide-ranging IPY findings result from more than 160 endorsed science projects assembled from researchers in more than 60 countries. Launched in March 2007, the IPY covers a two-year period to March 2009 to allow for observations during the alternate seasons in both polar regions. A joint project of WMO and ICSU, IPY spearheaded efforts to better monitor and understand the Arctic and Antarctic regions, with international funding support of about US$ 1.2 billion over the two-year period.
IPY has provided a critical boost to polar research during a time in which the global environment is changing faster than ever in human history. It now appears clear that the Greenland and Antarctic ice sheets are losing mass contributing to sea level rise. Warming in the Antarctic is much more widespread than it was thought prior to the IPY, and it now appears that the rate of ice loss from Greenland is increasing.
Researchers also found that in the Arctic, during the summers of 2007 and 2008, the minimum extent of year-round sea ice decreased to its lowest level since satellite records began 30 years ago. IPY expeditions recorded an unprecedented rate of sea-ice drift in the Arctic as well. Due to global warming, the types and extent of vegetation in the Arctic shifted, affecting grazing animals and hunting.
Other evidence for global warming comes from IPY research vessels that have confirmed above-global-average warming in the Southern Ocean. A freshening of the bottom water near Antarctica is consistent with increased ice melt from Antarctica and could affect ocean circulation. Global warming is thus affecting Antarctica in ways not previously identified.
IPY research has also identified large pools of carbon stored as methane in permafrost. Thawing permafrost threatens to destabilize the stored methane -a greenhouse gas- and send it into the atmosphere. Indeed, IPY researchers along the Siberian coast observed substantial emissions of methane from ocean sediments.
In the area of biodiversity, surveys of the Southern Ocean have uncovered a remarkably rich, colourful and complex range of life. Some species appear to be migrating poleward in response to global warming. Other IPY studies reveal interesting evolutionary trends such as many present-day deep-sea octopuses having originated from common ancestor species that still survive in the Southern Ocean.
IPY has also given atmospheric research new insight. Researchers have discovered that North Atlantic storms are major sources of heat and moisture for the polar regions. Understanding these mechanisms will improve forecasts of the path and intensity of storms. Studies of the ozone hole have benefited from IPY research as well, with new connections identified between the ozone concentrations above Antarctica and wind and storm conditions over the Southern Ocean. This information will improve predictions of climate and ozone depletion.
Many Arctic residents, including indigenous communities, participated in IPY’s projects. Over 30 of these projects addressed Arctic social and human science issues, including food security, pollution, and other health issues, and will bring new understanding to addressing these pressing challenges. “IPY has been the catalyst for the development and strengthening of community monitoring networks across the North” said David Carlson, Director of the IPY International Programme Office. “These networks stimulate the information flow among communities and back and forth from science to communities.”
The increased threats posed by climate change make polar research a special priority. The “State of Polar Research” document not only describes some of the striking discoveries during IPY, it also recommends priorities for future action to ensure that society is best informed about ongoing polar change and its likely future evolution and global impacts. A major IPY science conference will take place in Oslo in June 2010.
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Adapted from materials provided by International Council for Science (ICSU).

World's Smallest Periscopes Peer At Cells From Several Sides At Once

The mirrored pyramidal wells device captures the images of four sides of a single grain of pollen from the sunflower in the lower right.

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A team of Vanderbilt scientists have invented the world's smallest version of the periscope and are using it to look at cells and other micro-organisms from several sides at once.
"With an off-the-shelf laboratory microscope you only see cells from one side, the top," says team member Chris Janetopoulos, assistant professor of biological sciences. "Not only can we see the tops of cells, we can view their sides as well – something biologists almost never see."
The researchers have dubbed their devices "mirrored pyramidal wells." As the name implies, they consist of pyramidal-shaped cavities molded into silicon whose interior surfaces are coated with a reflective layer of gold or platinum. They are microscopic in dimension – about the width of a human hair – and can be made in a range of sizes to view different-sized objects. When a cell is placed in such a well and viewed with a regular optical microscope, the researcher can see several sides simultaneously.

"This technology is exciting because these mirrored wells can be made at very low cost, unlike other, more complex methods for 3D microscopy," says Assistant Professor of the Practice of Biomedical Engineering Kevin Seale.
According to Ron Reiserer, "This could easily become as ubiquitous as the microscope slide and could replace more expensive methods currently used to position individual cells." Reiserer is a lab manager at the Vanderbilt Institute for Integrative Biosystems Research and Education (VIIBRE) who helped design the protocol used to make the micropyramids.
The Vanderbilt group is not the first to make microscopic pyramidal wells, but it is the first to apply them to make 3D images of microorganisms. In 2006, a group of scientists in England created pyramidal micromirrors and applied them to trapping atoms. And last spring researchers at the National Institute of Standards and Technology used similar structures to track nanoparticles.
The Vanderbilt researchers reported their achievement last September in the Journal of Microscopy. Dmitry A. Markov and Igor Ges, research associates in biomedical engineering; undergraduate researcher Charlie Wright and John P. Wikswo, Gordon A. Cain University Professor and Director of VIIBRE, participated in the development with Janetopoulos, Seale and Reiserer.
So far, the researchers have used the mirrored wells to examine how protozoa swim and cells divide. "The method is particularly well suited for studying dynamic processes within cells because it can follow them in three dimensions," says Janetopoulos. Researchers in his lab have used the wells to track the 3D position of the centrosome – the specialized region of a cell next to the nucleus that is the assembly point where the microscopic polymer tubes that serve as part of the cell's cytoskeleton are assembled before cell division and broken down afterwards.
The mirrored pyramidal wells provide a high resolution, multi-vantage-point form of microscopy that also makes it easier for researchers to measure a number of important cell properties. For his senior thesis, for example, Wright explored how the technique can be used to measure the volume of individual yeast cells with unprecedented accuracy. In addition, Wikswo and Markov plan to create mirrored microchannels to measure how cells are deformed under stress induced by fluid flowing through hair-width channels in order to determine how fluid flow affects cell behavior and attachment.
A popular method for studying biological processes uses genetic engineering to attach genes that produce fluorescent molecules to different cell structures such as specific surface receptors. This procedure makes the targeted cell structures light up when illuminated by ultraviolet light, but strong UV light also has the potential to damage the structures. If the engineered cell structures are put in a micropyramidal well, the fluorescent light that is emitted toward the mirrored sides is reflected upward toward the microscope, allowing the researchers to reduce the intensity of the UV light and its potential for damaging the engineered cells.
According to Janetopoulos, the micropyramids also have a major advantage for single molecule studies. Optical noise is a constant problem when working at the low light levels involved. Being able to pinpoint actual light sources in two or three dimensions allows the researchers to reject spurious signals. This should be useful in quantitative fluorescence or bioluminescence studies: Cells can be genetically modified to glow in the dark to provide a measure of cellular metabolic activity or the expression of a specific gene.
The research was funded in part by a grant from the Air Force Office of Scientific Research. Vanderbilt University has applied for a patent on the use of the pyramidal mirrored wells for simultaneous, multi-vantage-point imaging.
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Adapted from materials provided by Vanderbilt University.

Next Generation Digital Maps Are Laser Sharp

The dynamics of rivers and streams can be more clearly identified using new laser-guided mapping technology, or lidar. This figure shows a segment of Maine’s Sheepscot River in a traditional digital topographic contour map (a); a lidar map (b); and the identification of Atlantic salmon spawning habitat (c). Airborne lidar mapping provides far greater resolution and allows researchers to connect the slope of the river with spawning habitat.

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Restoring habitat for spawning species of fish, such as Atlantic salmon, starts with a geological inventory of suitable rivers and streams, and the watershed systems that support them. But the high-tech mapping tools available to geologists and hydrologists have had their limits.

Now, lasers beamed from planes overhead are adding greater clarity to mapping streams and rivers and interpreting how well these bodies of water can help maintain or expand fish stocks, according to a new study.
"It's kind of like going from your backyard telescope to the Hubble telescope," says Boston College Geologist Noah P. Snyder. "Restoring fish habitat is just one example. For the fisherman, backpacker, forester, land use planner or developer – anyone who uses map data – this new technology is the next revolution in mapping."

Airborne laser elevation (or lidar) surveys provide a 10-fold improvement in the precision with which topographical features are measured.
Lidar represents the latest technology to improve digital topographical maps – known as digital elevation models, or DEMs. Pulsing laser beams released by a lidar device from a plane overhead bounce off of rocks, trees, soil, even water, and send signals back to the device, which makes topographical calculations based on the time it takes the laser signal to return at the speed of light.
Hundreds of beams produce a dynamic topographical picture, Snyder says. In the case of streams and rivers, the technology means that channel features such as water surface, bank edges, floodplains, even the slope of a stream, can be measured, he reports in the journal.
In addition, lidar provides new types of data about the vegetation that covers a particular watershed, such as the height and density of the tree canopy, Snyder says.
"We can look at much finer scale features in streams using a remote mapping technique, as opposed to field work over the entire lengths of streams," says Snyder, chairman of the steering committee of the National Center for Airborne Laser Mapping. "Digitally, we can now connect topographical features to habitat characteristics or the habitat that needs to be restored."
That means geologists and other earth scientists will be able to digitally search large swaths of lidar-mapped territory for a particular feature of interest – like salmon habitat or particularly steep sections of streams – then narrow down likely candidates for field study.
"I don't think this will replace field investigations, but it will allow us to better focus our field investigations," says Snyder, an expert in river geology, with a particular focus on restoration.
DEM technology, which digitized topographical maps in the early 1990s, led to breakthroughs in research ranging from the relationship between hillside and stream processes to the response of rivers to climate change. But the technology did reveal some limits, such as difficult profiling relatively smooth landscapes.
Traditional DEMs offer a resolution that provides one measure of elevation value for every 10-square meters of ground. Lidar mapping offers one measure of elevation value for each square meter, reports Snyder, whose research was funded by the National Science Foundation.
The amount of land currently mapped using lidar is gradually expanding. The state of Connecticut is the only stated entirely mapped via lidar. Pennsylvania has embarked on a lidar mapping project. Researchers, government agencies and private companies are increasingly using the technology to speed the creation of the next generation of maps, Snyder says.

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Adapted from materials provided by Boston College, viaEurekAlert!, a service of AAAS.

'Quantum Data Buffering' Scheme Demonstrated; Potentially Useful For Quantum Computers

Closeup of two "quantum images" created with the help of a "pump" laser beam. The two images are "entangled," so that if there is a change in the intensity in one region ("pixel") of the image, there would be an identical change in the intensity in the corresponding pixel in the second image. In this experiment, one of the images is delayed on its arrival to a detector, so that the correlations between the two images can be out of sync by up to 27 nanoseconds, something that is potentially useful for managing data to a future "quantum computer."

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Pushing the envelope of Albert Einstein's "spooky action at a distance," known as entanglement, researchers at the Joint Quantum Institute (JQI) of the Commerce Department's National Institute of Standards and Technology (NIST) and the University of Maryland have demonstrated a "quantum buffer," a technique that could be used to control the data flow inside a quantum computer. Quantum computers could potentially speed up or expand present capabilities in decrypting data, searching large databases, and other tasks.
The new research is published in the Feb. 12 issue of the journal Nature.
"If you want to set up some sort of communications system or a quantum information-processing system, you need to control the arrival time of one data stream relative to other data streams coming in," says JQI's Alberto Marino, lead author of the paper. "We can accomplish the delay in a compact setup, and we can rapidly change the delay if we want, something that would not be possible with usual laboratory apparatus such as beamsplitters and mirrors," he says.

This new work follows up on the researchers' landmark creation in 2008 of pairs of multi-pixel quantum images. A pair of quantum images is "entangled," which means that their properties are linked in such a way that they exist as a unit rather than individually. In the JQI work, each quantum image is carried by a light beam and consists of up to 100 "pixels." A pixel in one quantum image displays random and unpredictable changes say, in intensity, yet the corresponding pixel in the other image exhibits identical intensity fluctuations at the same time, and these fluctuations are independent from fluctuations in other pixels. This entanglement can persist even if the two images are physically disconnected from one another.
By using a gas cell to slow down one of the light beams to 500 times slower than the speed of light, the group has demonstrated that they could delay the arrival time of one of the entangled images at a detector by up to 27 nanoseconds. The correlations between the two entangled images still occur—but they are out of sync. A flicker in the first image would have a corresponding flicker in the slowed-down image up to 27 nanoseconds later.
While such "delayed entanglement" has been demonstrated before, it has never been accomplished in information-rich quantum images. Up to now, the "spooky action at a distance" has usually been delayed in single-photon systems.
"What gives our system the potential to store lots of data is the combination of having multiple-pixel images and the possibility of each pixel containing 'continuous' values for properties such as the intensity," says co-author Raphael Pooser.
To generate the entanglement, the researchers use a technique known as four-wave mixing, in which incoming light waves are mixed with a "pump" laser beam in a rubidium gas cell to generate a pair of entangled light beams. In their experiment, the researchers then send one of the entangled light beams through a second cell of rubidium gas where a similar four-wave mixing process is used to slow down the beam. The beam is slowed down as a result of the light being absorbed and re-emitted repeatedly in the gas. The amount of delay caused by the gas cell can be controlled by changing the temperature of the cell (by modifying the density of the gas atoms) and also by changing the intensity of the pump beam for the second cell.
This demonstration shows that this type of quantum buffer could be particularly useful for quantum computers, both in its information capacity and its potential to deliver data at precisely defined times.
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Adapted from materials provided by National Institute of Standards and Technology.

Materials Science Mystery Of 'Hidden Order' Solved: How A New Phase Arises And Why

How does a new phase arise, and why? New research points to an explanation of what has up until now been an unsolved riddle in materials science.

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“One of the most important problems in materials science solved,” reports Professor Peter Oppeneer of Uppsala University. Together with three colleagues, he has managed to explain the hitherto unsolved riddle in materials science known as ‘the hidden order' - how a new phase arises and why.
This is a discovery that can be of great importance to our understanding of how new material properties occur, how they can be controlled and exploited in the future.
For a long time researchers have attempted to develop the superconducting materials of the future that will be able to conduct energy without energy losses, something of great importance to future energy production. But one piece of the puzzle has been missing. There are several materials that evince a clear phase shift in all thermodynamic properties when the temperature falls below a certain transitional temperature, but no one has been able to explain the new collective order in the material. Until now, it has been called the hidden order.

"The hidden order was discovered 24 years ago, and for all these years scientists have tried to find an explanation, but so far no one has succeeded. This has made the question one of the hottest quests in materials science. And now that we can explain how the hidden order in materials occurs, in a manner that has never been seen before, we have solved one of the most important problems of our day in this scientific field," says Professor Peter Oppeneer.
Four physicists from Uppsala University, led by Peter Oppeneer and in collaboration with John Mydosh from the University of Cologne, who discovered the hidden order 24 years ago, show through large-scale calculations how the hidden order occurs. Extremely small magnetic fluctuations prompt changes in the macroscopic properties of the material, so an entirely new phase arises, with different properties.
"Never before have we seen the so-called ‘magnetic spin excitations' produce a phase transition and the formation of a new phase. In ordinary material this excitation cannot change the phase and properties of the material because it is too weak. But now we have shown that this is in fact possible," says Peter Oppeneer.
What explains in detail all of the physical phenomena in the hidden order is a computer-based theory. Among other applications, it can be used to better understand high-temperature superconducting materials and will thus be important in the development of new superconducting materials and future energy production.
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Adapted from materials provided by Uppsala Universitet.

Taking The Stress Out Of Magnetic Field Detection

Transmission electron microscope (TEM) images show sections of a continuous 400-nanometer-thick magnetic film of a nickle-iron-copper-molybdenum alloy (top) and a film of the same alloy layered with silver every 100 nanometers (bottom). By relieving strain in the film, the silver layers promote the growth of notably larger crystal grains in the layered material as compared to the monolithic film (several are highlighted for emphasis). Electron diffraction patterns (insets) tell a similar story—the material with larger crystal grains display sharper, more discrete scattering patterns. (Color added for clarity.)

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Researchers at the National Institute of Standards and Technology (NIST) have discovered that a carefully built magnetic sandwich that interleaves layers of a magnetic alloy with a few nanometers of silver “spacer” has dramatically enhanced sensitivity—a 400-fold improvement in some cases.

This material could lead to greatly improved magnetic sensors for a wide range of applications from weapons detection and non-destructive testing to medical devices and high-performance data storage.
Those applications and many others are based on thin films of magnetic materials in which the direction of magnetization can be switched from one orientation to another. An important characteristic of a magnetic film is its saturation field, the magnitude of the applied magnetic field that completely magnetizes the film in the same direction as the applied field—the smaller the saturation field, the more sensitive the device.

The saturation field is often determined by the amount of stress in the film—atoms under stress due to the pull of bonds with neighboring atoms are more resistant to changing their magnetic orientation. Metallic films develop not as a single monolithic crystal, like diamonds, but rather as a random mosaic of microscopic crystals called grains. Atoms on the boundaries between two different grains tend to be more stressed, so films with a lot of fine grains tend to have more internal stress than coarser grained films. Film stress also increases as the film is made thicker, which is unfortunate because thick films are often required for high magnetization applications.
The NIST research team discovered that magnetic film stress could be lowered dramatically by periodically adding a layer of a metal, having a different crystal structure or lattice spacing, in between the magnetic layers. Although the mechanism isn’t completely understood, according to lead author William Egelhoff Jr., the intervening layers disrupt the magnetic film growth and induce the creation of new grains that grow to be larger than they do in the monolithic films. The researchers prepared multilayer films with layers of a nickel-iron-copper-molybdenum magnetic alloy each 100 nanometers (nm) thick, interleaved with 5-nm layers of silver. The structure reduced the tensile stress (over a monolithic film of equivalent thickness) by a factor of 200 and lowered the saturation field by a factor of 400.
The work has particular application in the design of “flux concentrators,” magnetic structures that draw in external magnetic field lines and concentrate them in a small region. Flux concentrators are used to amplify fields in compact magnetic sensors used for a wide variety of applications.
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Adapted from materials provided by National Institute of Standards and Technology.

Hydrogen Fuel From Woodchips And Other Non-food Sources

Wood chips. Tomorrow's fuel-cell vehicles may be powered by enzymes that consume cellulose from woodchips or grass and exhale hydrogen.

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Tomorrow's fuel-cell vehicles may be powered by enzymes that consume cellulose from woodchips or grass and exhale hydrogen.
Researchers at Virginia Tech, Oak Ridge National Laboratory (ORNL), and the University of Georgia have produced hydrogen gas pure enough to power a fuel cell by mixing 14 enzymes, one coenzyme, cellulosic materials from nonfood sources, and water heated to about 90 degrees (32 degrees Celsius).
The group announced three advances from their "one pot" process: 1) a novel combination of enzymes, 2) an increased hydrogen generation rate -- to as fast as natural hydrogen fermentation, and 3) a chemical energy output greater than the chemical energy stored in sugars – the highest hydrogen yield reported from cellulosic materials. "In addition to converting the chemical energy from the sugar, the process also converts the low-temperature thermal energy into high-quality hydrogen energy – like Prometheus stealing fire," said Percival Zhang, assistant professor of biological systems engineering in the College of Agriculture and Life Sciences at Virginia Tech.

"It is exciting because using cellulose instead of starch expands the renewable resource for producing hydrogen to include biomass," said Jonathan Mielenz, leader of the Bioconversion Science and Technology Group at ORNL.
The researchers used cellulosic materials isolated from wood chips, but crop waste or switchgrass could also be used. "If a small fraction – 2 or 3 percent – of yearly biomass production were used for sugar-to-hydrogen fuel cells for transportation, we could reach transportation fuel independence," Zhang said. (He added that the 3 percent figure is for global transportation needs. The U.S. would actually need to convert about 10 percent of biomass – which would be 1.3 billion tons of usable biomass).
The research is supported by the Air Force Office of Scientific Research; Zhang's DuPont Young Professor Award, and the U.S. Department of Energy.
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Adapted from materials provided by Virginia Tech, viaEurekAlert!, a service of AAAS.