Back to the main page

Archives Of Science Blog

Subscribe To Science Blog RSS Feed  RSS content feed What is RSS feed?


October 3, 2006, 10:02 PM CT

Nanotechnology to Stop Weaponized Anthrax

Nanotechnology to Stop Weaponized Anthrax
Picture a spider web coated with sugar. But instead of luring in unsuspecting creatures, this spider web pulls in deadly anthrax spores, rendering them harmless.

Clemson University chemist Ya-Ping Sun and his research team have developed such a countermeasure strategy to weaponized anthrax, a biological agent used by a terrorist or terrorists that killed five Americans in 2001. The Clemson team's findings are published online in the "Journal of the American Chemical Society".

"For anthrax to be effective, it has to be made into a fine powder that can easily enter the lungs when inhaled. That is what makes it lethal," said Sun. "What we have done is come up with an agent that clings to the anthrax spores to make their inhalation into the lungs difficult".

Anthrax spores are covered with carbohydrates, or simple sugars, that are used to communicate with or attract other biological species. The Clemson team used carbon nanotubes as a platform or scaffolding for displaying sugar molecules that would attract the anthrax spores. Carbon nanotubes are hollow tubes made of carbon atoms. Typically one-hundred thousandth the thickness of a single human hair, nanotubes are formed from intensely heated carbon. When sugar coated, the carbon nanotubes bind with the anthrax spores, creating clusters that are too large to be inhaled -- stopping their infection and destruction.........

Posted by: John      Permalink         Source


October 2, 2006, 10:08 PM CT

Why Ultramarine Blue Fades

Why Ultramarine Blue Fades
The 20-year restoration of Michelangelo's frescoes on the ceiling of the Sistine Chapel has left visitors in awe of the work's original majesty--notably the brilliance of the blue that graces the Last Judgment's sky. Recent investigations into this shade of blue--ultramarine blue--have brought to light the pigment's tendency to fade. Is it possible that the longevity of such a masterpiece as the Last Judgment could be in peril?

Scientists at New York University and Pratt Institute now have the answer to why it fades, which gives the art world direction on how to protect the works of past and future masters.

The natural ultramarine pigment, obtained from the semi-precious stone lapis lazuli, has been one of the most valued pigments by European painters since the late 13th century. Before the 19th century, the only known source of lapis lazuli was in the quarries of Badakhshan (northeastern Afghanistan), a site visited and described by Marco Polo. He wrote: "There is a mountain in that region where the finest azure [lapis lazuli] in the world is found. It appears in veins like silver streaks." Lapis lazuli provided not only a vibrant blue color unmatched by any other pigment available at the time, but it added a divine nature to the artwork in which it was used. Since it was valued more highly than gold, its use typically conveyed the high status of a work's commissioner. Ultramarine was the pigment often reserved to paint the mantel of the Virgin Mary.........

Posted by: Edwin      Permalink         Source


October 2, 2006, 9:29 PM CT

A Magnetic-Semiconductor Sandwich

A Magnetic-Semiconductor Sandwich
Scientists at Ohio University have created an improved magnetic semiconductor that solves a problem spintronics researchers have been investigating for years.

Unlike classic or vintage electronics that operate on electronic charges, spin-based electronics focuses on the spin of electrons to carry and store information. Scientists predict spintronics will revolutionize the electronics industry by making devices faster, improving storage capacity and reducing the amount of power needed to run them.

Spintronics technology has not been widely applied yet, however, because researchers have had difficulty controlling, manipulating and measuring the electrons.

In a paper published online today in Physical Review Letters, a team of Ohio University and Ohio State University researchers led by postdoctoral fellow Erdong Lu have created an effective interface between a semiconductor and ferromagnetic metal. The two-layer "sandwich" of gallium nitride (GaN) and manganese gallium (MnGa) nearly eliminates any intermixing of the two layers and allows the spin to be "tuned".

"We found a way to grow the metal on the semiconductor. The crystalline match between the two materials was nearly perfect. The advantage of this finding is in the growth process. By adjusting the conditions of the growth, we can tune the spin," said Arthur Smith, associate professor of physics and astronomy and director of Ohio University's Nanoscale & Quantum Phenomena Institute.........

Posted by: John      Permalink         Source


October 2, 2006, 8:17 PM CT

How To Make A Wood-plastic Composite?

How To Make A Wood-plastic Composite? Image courtesy of http://www.omnexus.com/
Wood science scientists in the College of Forestry at Oregon State University have developed new wood-plastic composites that are stronger and less expensive than any similar products now available a major breakthrough for this growing industry.

Wood-plastic composites, often used for such things as outdoor decking, are one of the fastest growing components of the wood composites industry. Some projections have suggested that these products, which were used for less than 1 percent of decking in the mid-1990s, may capture 20 percent of that market by 2010.

"Composite products made from wood and plastic are highly desirable for their low maintenance and ability to resist rot," said Kaichang Li, an associate professor in the OSU Department of Wood Science and Engineering. "But their use has been limited because of high cost and low strength, a result of inadequate adhesion between the wood fibers and plastic".

Fundamentally, Li said, this is because wood and plastic are like oil and water, and do not mix well. Wood is hydrophilic it absorbs water and plastic is hydrophobic, repelling it. A "compatibilizer," typically a polymer that bridges the interface between the wood and plastic in these products, improves stress transfer and increases their strength and stiffness.........

Posted by: John      Permalink         Source


October 1, 2006, 7:10 PM CT

Stellar Birth Control In The Early Universe

Stellar Birth Control In The Early Universe Extremely massive black holes in the centers of galaxies may serve as 'cosmic contraceptives' in the early Universe, suppressing the birth of new stars.
Credit: NASA and the Hubble Heritage Team (STScI/AURA
An international team of astronomers based at Yale and Leiden University in The Netherlands found that "old stars" dominated many large galaxies in the early universe, raising the new question of why these galaxies progressed into "adulthood" so early in the life of the universe.

Every year only a handful of new stars are born out of the gas that fills the space between the stars in galaxies like the Milky Way. To account for the large number of stars in the Universe today, about 400 billion in the Milky Way alone, it was thought that the "stellar birth rate" must have been much higher in the past.

Surprisingly, in this study appearing in the October 2 issue of Astrophysical Journal, astronomers using the 8.1m Gemini telescope in Chile report that many of the largest galaxies in the Universe had a very low stellar birth rate even when the Universe was only about 20 percent of its present age.

"Our new results imply that the stars in many large galaxies were born when the Universe was in its infancy, in the first few billion years after the Big Bang," said team leader Mariska Kriek, a PhD student from Leiden University and Yale. "The results confirm what some astronomers had suspected -- galaxies seem to have some method of 'birth control' that is very effective".........

Posted by: Edwin      Permalink         Source


September 28, 2006, 10:17 PM CT

Watch How Planets Form

Watch How Planets Form
With the VISIR instrument on ESO's Very Large Telescope, astronomers have mapped the disc around a star more massive than the Sun. The very extended and flared disc most likely contains enough gas and dust to spawn planets. It appears as a precursor of debris discs such as the one around Vega-like stars and thus provides the rare opportunity to witness the conditions prevailing prior to or during planet formation.

"Planets form in massive, gaseous and dusty proto-planetary discs that surround nascent stars. This process must be rather ubiquitous as more than 200 planets have now been found around stars other than the Sun," said Pierre-Olivier Lagage, from CEA Saclay (France) and leader of the team that carried out the observations. "However, very little is known about these discs, especially those around stars more massive than the Sun. Such stars are much more luminous and could have a large influence on their disc, possibly quickly destroying the inner part".

The astronomers used the VISIR instrument [1] on ESO's Very Large Telescope to map in the infrared the disc surrounding the young star HD 97048. With an age of a few million years [2], HD 97048 belongs to the Chameleon I dark cloud, a stellar nursery 600 light-years away. The star is 40 times more luminous than our Sun and is 2.5 times as massive.........

Posted by: Edwin      Permalink         Source


September 28, 2006, 8:38 PM CT

Membranes At The Nanoscale

Membranes At The Nanoscale
The composition of lipid membranes, similar to those that surround living cells, can now be mapped at the nanometer scale. The work, by scientists at Stanford University, the Lawrence Livermore National Laboratory and UC Davis, is reported in the Sept. 29 issue of the journal Science.

All living cells are wrapped in a double-layered membrane of fatty lipid molecules. Components of the membrane can move sideways and organize into patches or other structures. This organization can affect, for example, important cell functions and vulnerability to viruses.

But it is very difficult to study these structures because they are so small, measured in tens of nanometers, said Marjorie Longo, professor of chemical engineering and materials science at UC Davis. A nanometer is a billionth of a meter, or about a thirty-millionth of an inch. Researchers want to address questions such as how dynamic or active the membrane is and how small the lipid patches are, she said. An atomic force microscope, which uses a fine needle to probe surfaces, can give a contour map of the surface but without chemical information.

The research group, led by Steven Boxer of Stanford University, used a highly focused beam of charged particles to scan the surface of artificial lipid membranes containing lipid patches developed in Longo's lab. Components of the membrane were previously labeled with heavy isotopes of carbon and nitrogen, mounted on silicon wafers and flash-freeze-dried to preserve structure.........

Posted by: John      Permalink         Source


September 28, 2006, 5:14 PM CT

Robomower To Mow Your Lawn

Robomower To Mow Your Lawn
From: popgadget:.

This reminds me of the iRobot vacuum cleaner, except this is for your lawn. The RoboMower RL850 features a "battery-powered three-blade, 21-inch (56cm) powerful cutting system equivalent to a 5.5 HP gas mower".

It cuts your lawn in a systematic crisscross pattern, travelling several times over the grass to make sure it gets every last blade.

How does it work, you ask? You need to install a special electric perimeter wire around your lawn, attached to the surface of the lawn with pegs every few feet. The wire is connected to a small battery powered current source called the Perimeter Switch. The RoboMower has a special senor so it stays inside the electronic fence. Charge it between uses and it's always at your command.

Oh yeah, it's $1,175.99, at Vacation Gadgets.........

Posted by: Edna      Permalink         Source


September 27, 2006, 8:57 PM CT

Glue Made From Ethanol More Than The Fuel Itself

Glue Made From Ethanol  More Than The Fuel Itself
Mixing up a batch of ethanol from alfalfa or switchgrass isn't nearly as efficient as creating it from corn, but that doesn't mean growing grass crops for fuel won't pay, says Paul Weimer.

Rather than dwelling on finding ways to squeeze extra ethanol out of biomass from crops such as switchgrass, Weimer is concentrating his research on the leftovers. He thinks that the large heap of fermentation residue from the ethanol-making process - what a number of people consider a byproduct - could be far more valuable than the ethanol itself.

"A lot of people want to do the same thing with biomass material that we've been doing with corn," says Weimer, a research microbiologist at the USDA-ARS Dairy Forage Research Center and associate professor of bacteriology at the University of Wisconsin-Madison. "They want to hit it with enzymes to break it down into sugars, and ferment those sugars into ethanol.

The problem with this, he explains, is that the enzymes needed to break down celluose biomass are very expensive, and they don't work nearly as effectively as the enzymes used to convert starch.

In fact, Weimer adds, both corn and cellulosic biomass must be subjected to costly pretreatment to maximize the ethanol yield.

"Our philosophy is a little bit different," Weimer says. "We believe that the fermentation residue may actually be more valuable than the ethanol. And it may mean that we can do without pretreatment".........

Posted by: John      Permalink         Source


September 27, 2006, 8:45 PM CT

More Efficiency In Harvest And Handling

More Efficiency In Harvest And Handling
Kevin Shinners wants farmers to put less energy into harvesting and handling biofuel crops - less fuel, less time and less labor.

As a field machinery specialist, Shinners has worked to improve the efficiency of harvesting forage for animals. Harvesting biomass crops poses similar challenges, he says.

"The biggest problem is there are way too many operations in the field," says Shinners, a professor of biological systems engineering and mechanical engineering at the University of Wisconsin-Madison. "Every time we handle this material, it costs real money".

Much of Shinners' research to date has focused on corn stover, the stalks and leaves left behind when grain is harvested. He has also embarked on a similar line of research on cost-effective harvesting of forage grasses, such as switchgrass, for both feed and fuel production.

Corn stover is usually left in the field or used as animal fodder, but it has tremendous potential as a cellulosic source of ethanol - if the shredding, drying, raking, bailing and transporting can be made less costly and less labor-intensive.

The U.S. Department of Energy predicts that this type of biomass will sell for $30-$40 per ton. Although this price is low compared to high-quality alfalfa, which can sell for $100-$120 per ton, the high-value corn grain provides stover with a valuable co-product, he notes.........

Posted by: Nora      Permalink         Source


Older Blog Entries   Older Blog Entries   1   2   3   4   5   6   7   8   9   10   11   12   13   14   15   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31