June 10, 2008, 8:15 PM CT

Lost Reds In Homer Painting

More than 30 years ago, when Northwestern University chemist Richard Van Duyne developed a powerful new sensing technique, he never thought he would be using it to learn more about treasures in the Art Institute of Chicago's collection -- including a watercolor recently featured in the museum's exhibition "Watercolors by Winslow Homer: The Color of Light".

In Homer's watercolor "For to be a Farmer's Boy," painted in 1887, some of the red and yellow pigments have faded in the sky, leaving that area virtually without color. Van Duyne, Charles E. and Emma H. Morrison Professor of Chemistry in the Weinberg College of Arts and Sciences, is working with Francesca Casadio, a conservation scientist at the Art Institute, to determine what the original colors were.

To solve this mystery, they are using surface enhanced Raman spectroscopy (SERS), the analytical technique pioneered by Van Duyne in 1977. SERS uses laser light and nanoparticles of precious metals to interact with molecules to show the chemical make-up of a particular dye.

SERS is a variation of Raman spectroscopy, a widely used technique first developed in the 1920s. What sets SERS apart is its ability to analyze extremely minute samples of organic dyes; some samples are so small they cannot be seen by the naked eye......... Posted by: Sarah      Read more         Source

June 9, 2008, 8:02 PM CT

New research refutes myth of pure Scandinavian race

team of forensic researchers at the University of Copenhagen has studied human remains found in two ancient Danish burial grounds dating back to the iron age, and discovered a man who appears to be of arabian origin. The findings suggest that human beings were as genetically diverse 2000 years ago as they are today and indicate greater mobility among iron age populations than was previously thought. The findings also suggest that people in the Danish iron age did not live and die in small, isolated villages but, on the contrary, were in constant contact with the wider world.

On the southern part of the island of Zealand in Denmark, lie two burial grounds known as Bøgebjerggård and Skovgaarde, which date back to the Danish iron age (c. 0-400 BC). Linea Melchior and forensic researchers from the University of Copenhagen analysed the mitocondrial DNA of 18 individuals buried on the sites and observed that there was as much genetic variation in their remains as one would expect to find in individuals of the present day. The research team also found DNA from a man, whose genetic characteristics indicate a man of Arabian origin.

The ancestors of the Danes were in contact with the wider world.

Archeologists and anthropologists know today that the concept of a single scandinavian genetic type, a scandinavian race that wandered to Denmark, settled there, and otherwise lived in complete isolation from the rest of the world, is a fallacy......... Posted by: William      Read more         Source

June 4, 2008, 10:49 PM CT

Prototype Hydrogen Storage Tank

A cryogenic pressure vessel developed and installed in an experimental hybrid vehicle by a Lawrence Livermore National Laboratory research team can hold liquid hydrogen for six days without venting any of the fuel.

Unlike conventional liquid hydrogen (LH2 tanks in prototype cars, the LLNL pressure vessel was parked for six days without venting evaporated hydrogen vapor.

The LLNL development has significantly increased the amount of time it takes to start releasing hydrogen during periods of long-term parking, as in comparison to today's liquid hydrogen tanks capable of holding hydrogen for merely two to four days.

LH2 tanks hold super-cold liquid hydrogen at around -420 Fahrenheit. Like water boiling in a tea kettle, pressure builds as heat from the environment warms the hydrogen inside. Current automotive LH2 tanks must vent evaporated hydrogen vapor after being parked three to four days, even when using the best thermal insulation available (200 times less conductive than Styrofoam insulation).

In recent testing of its prototype hydrogen tank onboard a liquid hydrogen (LH2) powered hybrid, LLNL's tank demonstrated a thermal endurance of six days and the potential for as much as 15 days, helping resolve a key challenge facing LH2 automobiles......... Posted by: Sarah      Read more         Source

June 3, 2008, 10:14 PM CT

Alaska Space Grant program launches B.E.A.R.

AlaskaThe Alaska Space Grant Program and the Arctic Amateur Radio Club formed the Balloon Experiment And Research Programor B.E.A.R. for shortin December 2007. The program's aim was to launch a high altitude balloon equipped with two amateur radio signals and more from Poker Flat Research Range in the spring of 2008. On May 10, BEAR participants met to inflate and launch their first balloon. It flew as high as 95,327 feet above Fairbanks in three hours, capturing more than 100 photos and video during its flight.

The balloon had three payloads in tow, all built and designed by Dan Wietchy of the Fairbanks-based Arctic Amateur Radio Club. The packages performed well, allowing B.E.A.R. participants to track and document the balloon's flight, and its subsequent recovery. The balloon was found less than seven miles from where it was launched at Poker Flat Research Range.

The Alaska Space Grant Program intends to expand B.E.A.R. into a larger program that will allow University of Alaska Fairbanks students the opportunity to fly payloads of their own design, and to conduct atmospheric research in the spring and fall. Faculty from the Geophysical Institute already are interested in designing graduate-level courses that will take advantage of this new arena to bolster hands-on student research......... Posted by: Tyler      Read more         Source

May 27, 2008, 9:37 PM CT

Robots go Where Scientists Fear to Tread

Researchers are diligently working to understand how and why the world's ice shelves are melting. While most of the data they need (temperatures, wind speed, humidity, radiation) can be obtained by satellite, it isn't as accurate as good old-fashioned, on-site measurement and static ground-based weather stations don't allow researchers to collect info from as a number of locations as they'd like.

Unfortunately, the locations in question are volatile ice sheets, possibly cracking, shifting and filling with water - not exactly a safe environment for scientists.

To help researchers collect the more detailed data they need without risking scientists' safety, scientists at the Georgia Institute of Technology, working with Pennsylvania State University, have created specially designed robots called SnoMotes to traverse these potentially dangerous ice environments. The SnoMotes work as a team, autonomously collaborating among themselves to cover all the necessary ground to gather assigned scientific measurements. Data gathered by the Snomotes could give researchers a better understanding of the important dynamics that influence the stability of ice sheets.

"In order to say with certainty how climate change affects the world's ice, researchers need accurate data points to validate their climate models," said Ayanna Howard, lead on the project and an associate professor in the School of Electrical and Computer Engineering at Georgia Tech. "Our goal was to create rovers that could gather more accurate data to help researchers create better climate models. It's definitely science-driven robotics."........ Posted by: Kevin      Read more         Source

May 22, 2008, 10:22 PM CT

Continued turbulence in Jupiter's atmosphere

Berkeley -- Increased turbulence and storms first observed on Jupiter more than two years ago are still raging, as per astronomers from the University of California, Berkeley, and the W. M. Keck Observatory in Hawaii, who snapped high-resolution pictures of the planet earlier this month.

Captured with NASA's Hubble Space Telescope (HST) and the 10-meter Keck II telescope, this so-called "major upheaval" on Jupiter involves stunning changes in the planet's atmosphere, said lead astronomer Imke de Pater, professor of astronomy at UC Berkeley.

The images are available on NASA's Web site, http://hubblesite.org/news/2008/23.

The upheaval was heralded in December 2005 by a color change from white to red of a large oval near the Great Red Spot, earning it the moniker Red Spot Jr. This oval, formally known as Oval BA, formed six years earlier through a merger of three large white ovals just south of the Great Red Spot - storms that formed in the early 1930s and were prominent in the Voyager era.

The new images, the first since Jupiter emerged from its passage behind the Sun, may show that Jupiter indeed is undergoing a major climate change, as predicted four years ago.

"One of the most notable changes we observe in both the Hubble and Keck images is the change from a rather bland, quiescent band surrounding the Great Red Spot just over a year ago to one that is incredibly turbulent at both sides of the spot," de Pater said. "During all prior HST observations and spacecraft encounters, starting with Voyager in 1979, such turbulence was seen only on the west or left side of the spot."........ Posted by: Brooke      Read more         Source

May 22, 2008, 10:03 PM CT

Pacific coast turning more acidic

An international team of researchers surveying the waters of the continental shelf off the West Coast of North America has discovered for the first time high levels of acidified ocean water within 20 miles of the shoreline, raising concern for marine ecosystems from Canada to Mexico.

Scientists aboard the Wecoma, an Oregon State University research vessel, also discovered that this corrosive, acidified water that is being upwelled seasonally from the deeper ocean is probably 50 years old, suggesting that future ocean acidification levels will increase since atmospheric levels of carbon dioxide have increased rapidly over the past half century.

Results of the study were published this week in Science Express.

When the upwelled water was last at the surface, it was exposed to an atmosphere with much lower CO₂ (carbon dioxide) levels than todays, pointed out Burke Hales, an associate professor in the College of Oceanic and Atmospheric Sciences at Oregon State University and an author on the Science study. The water that will upwell off the coast in future years already is making its undersea trek toward us, with ever-increasing levels of carbon dioxide and acidity.

The coastal ocean acidification train has left the station, Hales added, and there not much we can do to derail it......... Posted by: Tyler      Read more         Source

May 21, 2008, 9:48 PM CT

Earth may hide a lethal carbon cache

CARBON buried in the Earth could ultimately determine the fate of our planets atmosphere. So concluded a pioneering meeting last week about the Earths long-neglected deep carbon cycle.

Carbon is locked away down in the Earths crust: in magma and old carbonate rocks buried by plate tectonics, in fossil fuels like coal and oil, and in ice lattices beneath the ocean bed. It has long been assumed that this carbon was largely cut off from the surface, and could safely be ignored when analysing the effect of greenhouse gases on climate.

Now it seems there may be much more deep carbon ready to spew out than we thought.

This realisation could have profound implications for our climate, argues Robert Hazen of the Carnegie Institution, who organised the meeting at the institutions Geophysical Laboratory in Washington DC. We may be on the verge of a transformational momenta glimpse of new, unexplored scientific territory, he says.

Perhaps the greatest threat of an unexpected release of carbon from the deep comes from an indirect effect of human-made CO2. Global warming could destabilise some deep carbon reserves, notably in clathrates - ice lattices which are found beneath the ocean floor and continental permafrost, and even under freshwater lakes like Lake Baikal in Siberia (pictured). These ice structures may hold trillions of tonnes of methane......... Posted by: Tyler      Read more         Source

May 20, 2008, 9:56 PM CT

New process could cause titanium price to tumble

Whether for stopping cars or bullets, titanium is the material of choice, but it has always been too expensive for all but the most specialized applications.

That could change, however, with a non-melt consolidation process being developed by Oak Ridge National Laboratory and industry partners. The new processing technique could reduce the amount of energy mandatory and the cost to make titanium parts from powders by up to 50 percent, making it feasible to use titanium alloys for brake rotors, artificial joint replacements and, of significant interest now, armor for military vehicles.

"We recently exhibited the new low-cost titanium alloy door made by ORNL for the Joint Light Tactical Vehicle, which is a next-generation combat vehicle," said Bill Peter, a researcher in ORNL's Materials Science and Technology Division. "By using a titanium alloy for the door, BAE Systems was able to reduce the weight of its vehicle yet at the same time decrease the threat of armor-piercing rounds."

The lightweight titanium alloy also improves the operation of the door and increases mobility of the vehicle, making it even more useful to the military.

Peter noted that the non-melt approach, which includes roll compaction for directly fabricating sheets from powder, press and sinter techniques to produce net shape components and extrusion, offers a number of advantages over traditional melt processing......... Posted by: Sarah      Read more         Source

May 20, 2008, 9:33 PM CT

Seeing clearly despite the clouds

Satellites taking atmospheric measurements might now be able to see blue skies as clearly as optimists do. Scientists have found a way to reduce cloud-induced glare when satellites measure blue skies on cloudy days, by as much as ten-fold in some cases. The result might lead to more accurate estimates of the amount of sunlight penetrating the atmosphere. Because clouds represent one of the largest areas of uncertainty, eventually this could lead to improved climate models.

Sunlight bouncing off clouds blinds satellites trying to determine how much the blue sky between is actually reflecting. Scientists at the Department of Energy's Pacific Northwest National Laboratory have observed that using an indirect measurement of that reflected light can bring the measurements of cloud-bordered blue skies to within about 10 percent of what other instruments indicate, the scientists report March 28 in Geophysical Research Letters.

"When scientists try to apply satellite technology originally developed for clear skies to partly cloudy conditions, they find additional light reflected from clouds," says PNNL atmospheric scientist Evgueni Kassianov. "We can't use the same technology we use for clear skies for complex cloudy skies".

Blue skies might seem empty, but they are full of naked-to-the-eye particles called aerosols, which are made up of water and bits of matter. These aerosols reflect sunlight. The more aerosols, the more sunlight is reflected back to the satellite. But on cloudy days, clouds bounce sunlight all around and make nearby aerosols seem brighter than they really are. Prior research has shown that clouds can brighten aerosols even up to three kilometers (almost two miles) away......... Posted by: Tyler      Read more         Source