Science & TechnologyS


Bulb

New PV Cell Generates Electricity From UV, Visible, Infrared Lights

Tetsuo Nozawa, Nikkei Electronics
Tech On
Tue, 23 Mar 2010 14:05 UTC
Image
The PV cell prototyped at the Kyoto Institute of Technology by adding cobalt to a p-type GaN thin film and laminating an n-type material (right). The cell with an absorbing layer measures 10 x 10mm. The surrounding thin rectangular patterns are electrodes. And the p-type GaN thin film without cobalt (left).
A Japanese research group prototyped a photovoltaic (PV) cell that can generate electricity from a wide wavelength band of light including ultraviolet light, visible light and infrared light.

The group, which is led by Saki Sonoda, associate professor at the Kyoto Institute of Technology, made the announcement March 19, 2010, at the 57th Spring Meeting of the Japan Society of Applied Physics.

The PV cell was realized by adding "3d transition metals" including manganese (Mn) to transparent composite semiconductors with a wide bandgap such as gallium nitride (GaN). It could enable to develop a highly-efficient PV cell by using a simply-joined cell without making a multi-junction cell.

Currently, the conversion efficiency of the new PV cell is low, but its open voltage (Voc) is as high as 2V.

The research group delivered a 90-minute lecture on the cell under the title "Nitride Semiconductor Added With Transition Metals as a Photoelectric Conversion Material for Ultraviolet, Visible and Infrared Lights ~ In the Aim of Realizing the Next-generation Super-efficient PV Cell With a Simple Element Structure."
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Blackbox

Mysterious radio waves emitted from nearby galaxy

Stephen Battersby
New Scientist
Wed, 14 Apr 2010 14:09 UTC
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© NASA/ESA/STScI/AURASomething in there is producing an unusually regular radio signal
There is something strange in the cosmic neighbourhood. An unknown object in the nearby galaxy M82 has started sending out radio waves, and the emission does not look like anything seen anywhere in the universe before.

"We don't know what it is," says co-discoverer Tom Muxlow of Jodrell Bank Centre for Astrophysics near Macclesfield, UK.

The thing appeared in May last year, while Muxlow and his colleagues were monitoring an unrelated stellar explosion in M82 using the MERLIN network of radio telescopes in the UK. A bright spot of radio emission emerged over only a few days, quite rapidly in astronomical terms. Since then it has done very little except baffle astrophysicists.

It certainly does not fit the pattern of radio emissions from supernovae: they usually get brighter over a few weeks and then fade away over months, with the spectrum of the radiation changing all the while. The new source has hardly changed in brightness over the course of a year, and its spectrum is steady.
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Meteor

Stunning Comet's Size Shocks Scientists


SPACE.com
Wed, 14 Apr 2010 01:13 UTC
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© Patrick BoomerPatrick Boomer, captured these photographs Southwest of Red Deer, Alberta, Canada. These comparison photos of Comet McNaught, taken on Jan. 6th, Jan. 7th and Jan 9th (2007) shows the difference a day makes. Both photos were taken at 5:36pm local time.
Comet McNaught, the so-called Great Comet of 2007, has been identified as the biggest comet measured to date, according to scientists, whose calculations were based on the comet's overall influence in space.

Instead of using the length of the comet's tail to measure the scale of the comet, astronomers used data from the ESA/NASA Ulysses spacecraft to determine the size of the region of space disturbed by the comet's presence - a cosmic wake across the solar system.

Through analysis of magnetometer data, scientists found evidence of a decayed shockwave surrounding the comet, which was created when ionized gas emitted from the comet's nucleus joined the fast-flowing particles of the solar wind. That, in turn, caused the solar wind around the comet to abruptly slow down.
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Pharoah

Biblical plagues really happened say scientists

Richard Gray
The Telegraph
Sat, 27 Mar 2010 17:03 UTC
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© GettyThe arrival of toxic algae would have forced frogs to leave the water where they lived
The Biblical plagues that devastated Ancient Egypt in the Old Testament were the result of global warming and a volcanic eruption, scientists have claimed.

Researchers believe they have found evidence of real natural disasters on which the ten plagues of Egypt, which led to Moses freeing the Israelites from slavery in the Book of Exodus in the Bible, were based.

But rather than explaining them as the wrathful act of a vengeful God, the scientists claim the plagues can be attributed to a chain of natural phenomena triggered by changes in the climate and environmental disasters that happened hundreds of miles away.

Comment: The whole point is that it serves the interests of religions to ascribe to natural disasters the "wrath of God". How would they hold power over the rest of us otherwise?

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Info

Fear of getting fat seen in healthy women's brain scans


Brigham Young University
Tue, 13 Apr 2010 15:11 UTC
A group of women in a new study seemed unlikely to have body image issues - at least their responses on a tried-and-true psychological screening presented no red flags.

That assessment changed when Brigham Young University researchers used MRI technology to observe what happened in the brain when people viewed images of complete strangers.

If the stranger happened to be overweight and female, it surprisingly activated in women's brains an area that processes identity and self-reflection. Men did not show signs of any self-reflection in similar situations.

"These women have no history of eating disorders and project an attitude that they don't care about body image," said Mark Allen, a BYU neuroscientist. "Yet under the surface is an anxiety about getting fat and the centrality of body image to self."

Allen makes his report with grad student Tyler Owens and BYU psychology professor Diane Spangler in the May issue of the psychological journal Personality and Individual Differences.
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Info

First Direct Recording Made of Mirror Neurons in Human Brain


Science Daily
Tue, 13 Apr 2010 14:57 UTC
Mirror Neuron
© University of California - Los AngelesMirror neurons, many say, are what make us human.
Mirror neurons, many say, are what make us human. They are the cells in the brain that fire not only when we perform a particular action but also when we watch someone else perform that same action.

Neuroscientists believe this "mirroring" is the mechanism by which we can "read" the minds of others and empathize with them. It's how we "feel" someone's pain, how we discern a grimace from a grin, a smirk from a smile.

Problem was, there was no proof that mirror neurons existed -- only suspicion and indirect evidence. Now, reporting in the April edition of the journal Current Biology, Dr. Itzhak Fried, a UCLA professor of neurosurgery and of psychiatry and biobehavioral sciences, Roy Mukamel, a postdoctoral fellow in Fried's lab, and their colleagues have for the first time made a direct recording of mirror neurons in the human brain.
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Telescope

Baby stars in the Rosette cloud


European Space Agency
Mon, 12 Apr 2010 18:50 UTC
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© ESA/PACS & SPIRE Consortium/HOBYS Key Programme ConsortiaThe Rosette molecular cloud, seen by Herschel.
Herschel's latest image reveals the formation of previously unseen large stars, each one up to ten times the mass of our Sun. These are the stars that will influence where and how the next generation of stars are formed. The image is a new release of 'OSHI', ESA's Online Showcase of Herschel Images.

The Rosette Nebula resides some 5,000 light years from Earth and is associated with a larger cloud that contains enough dust and gas to make the equivalent of 10,000 Sun-like stars. The Herschel image shows half of the nebula and most of the Rosette cloud. The massive stars powering the nebula lie to the right of the image but are invisible at these wavelengths. Each colour represents a different temperature of dust, from - 263ºC (only 10ºC above absolute zero) in the red emission to - 233ºC in the blue.
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Magnify

Deciphering the mysteries of an ancient seafloor goliath

Kristin Ludwig
Integrated Ocean Drilling Program Management International
Mon, 12 Apr 2010 18:40 UTC
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© John Beck, IODP/TAMUCurator Chad Broyles (IODP-USIO/Texas A&M University; back to camera), Expedition Project Manager and Staff Scientist Jörg Geldmacher (IODP-USIO/Texas A&M University), Co-Chief Scientist Takashi Sano (National Museum of Nature and Science, Tokyo, Japan), and Co-Chief Scientist Will Sager (Texas A&M University, USA) discuss a core recovered from Shatsky Rise.
The eruptions of "supervolcanoes" on Earth's surface have been blamed for causing mass extinctions, belching large amounts of gases and particles into the atmosphere, and re-paving the ocean floor. The result? Loss of species, increased greenhouse gases in the atmosphere, and changes in ocean circulation. Despite their global impact, the origin and triggering mechanism of these eruptions remain poorly understood. New data collected during a recent Integrated Ocean Drilling Program (IODP) scientific research expedition in the Pacific Ocean may provide clues to unlocking this unsolved mystery in Earth's geologic record.

In fall 2009, an international team of scientists participating in IODP Expedition 324 "Shatsky Rise Formation," drilled five sites in the ocean floor to study the origin of the 145 million-year-old Shatsky Rise volcanic mountain chain. Located approximately 1500 kilometers (930 miles) east of Japan, Shatsky Rise measures roughly the size of California. This underwater mountain chain represents one of the largest supervolcanoes in the world: the top of Shatsky Rise lies three and a half kilometers (about two miles) below the sea surface, while its base plunges to nearly six kilometers (four miles) below the surface. Shatsky Rise is composed of layers of hardened lava, with individual lava flows that are up to 23 meters (75 feet) thick
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Pistol

New Technique Turns T-Shirts into Body Armor

Michelle Bryner
TechNewsDaily
Mon, 12 Apr 2010 18:33 UTC
Those bulky, bulletproof vests could become a thing of the past. Their replacement: Your T-shirt, but with a special coating.

Bulletproofing can be done in one of two ways. The first, old-school approach relies on hard plates of metal or ceramic, which deflect oncoming bullets. A more elegant way, perhaps, is the use of a network of fibers - the approach taken by Kevlar - to "catch" the bullet, much like a hockey goalie catches a flying puck.

Kevlar has made its mark in body armor, as the technology is used in vests, helmets, and other gear for law enforcement, corrections officers and the military. However, it's expensive, which limits its use to those who can drop hundreds of dollars for protection.
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Cloud Lightning

Sun Rules Earth's Mysterious "Night Shining" Clouds


New Scientist
Mon, 12 Apr 2010 06:00 UTC
Noctilucent CLouds
© FLPAMysterious 'night shining' clouds have a solar controller.
The comings and goings of noctilucent or "night shining" clouds in the extreme upper atmosphere may be linked to the sun's rotation.

Noctilucent clouds appear about 80 kilometres above the Earth in each hemisphere's summer. Their extent and brightness varies over days, weeks and years, but no one knows why.

Now Charles Robert of the University of Bremen, Germany, and colleagues think they have an answer. By measuring changes in the light reflected from the clouds, they found that the clouds appear to wax and wane in prevalence over a 27-day cycle. As the sun takes 27 days to rotate around its axis, the team suggest a link (Journal of Geophysical Research, DOI: 10.1029/2009jd012359).
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