Sunday, February 24, 2013

Graphene: A material that multiplies the power of light

Feb. 24, 2013 ? Bottles, packaging, furniture, car parts... all made of plastic. Today we find it difficult to imagine our lives without this key material that revolutionized technology over the last century. There is wide-spread optimism in the scientific community that graphene will provide similar paradigm shifting advances in the decades to come. Mobile phones that fold, transparent and flexible solar panels, extra thin computers... the list of potential applications is endless.

The most recent discovery published in Nature Physics and made by researchers at the Institute of Photonic Science (ICFO), in collaboration with Massachusetts Institute of Technology, USA, Max Planck Institute for Polymer Research, Germany, and Graphenea S.L. Donostia-San Sebastian, Spain, demonstrate that graphene is able to convert a single photon that it absorbs into multiple electrons that could drive electric current (excited electrons) -- a very promising discovery that makes graphene an important alternative material for light detection and harvesting technologies, now based on conventional semiconductors like silicon.

"In most materials, one absorbed photon generates one electron, but in the case of graphene, we have seen that one absorbed photon is able to produce many excited electrons, and therefore generate larger electrical signals" explains Frank Koppens, group leader at ICFO. This feature makes graphene an ideal building block for any device that relies on converting light into electricity. In particular, it enables efficient light detectors and potentially also solar cells that can harvest light energy from the full solar spectrum with lower loss.

The experiment consisted in sending a known number of photons with different energies (different colors) onto a monolayer of graphene. "We have seen that high energy photons (e.g. violet) are converted into a larger number of excited electrons than low energy photons (e.g. infrared). The observed relation between the photon energy and the number of generated excited electrons shows that graphene converts light into electricity with very high efficiency. Even though it was already speculated that graphene holds potential for light-to-electricity conversion, it now turns out that it is even more suitable than expected!" explains Tielrooij, researcher at ICFO.

Although there are some issues for direct applications, such as graphene's low absorption, graphene holds the potential to cause radical changes in many technologies that are currently based on conventional semiconductors. "It was known that graphene is able to absorb a very large spectrum of light colors. However now we know that once the material has absorbed light, the energy conversion efficiency is very high. Our next challenge will be to find ways of extracting the electrical current and enhance the absorption of graphene. Then we will be able to design graphene devices that detect light more efficiently and could potentially even lead to more efficient solar cells." concludes Koppens.

Scientists, industries and the European Commission are so convinced of the potential of graphene to revolutionize the world economy that they promise an injection of ?1.000 million in graphene research.

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The above story is reprinted from materials provided by ICFO-The Institute of Photonic Sciences, via EurekAlert!, a service of AAAS.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. K. J. Tielrooij, J. C. W. Song, S. A. Jensen, A. Centeno, A. Pesquera, A. Zurutuza Elorza, M. Bonn, L. S. Levitov, F. H. L. Koppens. Photoexcitation cascade and multiple hot-carrier generation in graphene. Nature Physics, 2013; DOI: 10.1038/nphys2564

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Source: http://feeds.sciencedaily.com/~r/sciencedaily/matter_energy/electricity/~3/5QHhG2DLkpc/130224142831.htm

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Russia meteor triggered nuclear warning system

The infrasonic waves from the detonation of a meteor over the Ural Mountains earlier this month was detected by 17 nuclear monitoring stations around the globe. ?

By Leonard David,?SPACE.com / February 22, 2013

This dashcam video frame grab shows a meteor streaking across the sky of Russia?s Ural Mountains earlier this month.

Nasha gazeta/www.ng.kz/AP/File

Enlarge

A far-flung system of detectors that make up a Comprehensive Nuclear-Test-Ban Treaty network made its largest ever detection when a meteor exploded over Russia?s Ural mountains last week.

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The Vienna, Austria-based Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) runs the International Monitoring System made up of infrasound stations. Infrasound is low frequency sound with a range of less than 10 Hertz. Humans cannot hear the low frequency waves that were emitted by the?meteor blast over Russia?on Friday (Feb. 15), but they were recorded by the CTBTO?s network of sensors as they travelled across continents.

When the space rock detonated, the blast was detected by 17 infrasound stations in the CTBTO?s network that track atomic blasts across Earth. The furthest station to record the sub-audible sound was some 9,320 miles (15,000 kilometers) away in Antarctica.

Huge infrasound event

Prior to the Russian meteor event, the largest infrasound event registered by 15 stations in the CTBTO?s network was the October 2009 meteor explosion (called a bolide) over Sulawesi, Indonesia. [See video of the intense meteor explosion]

In a CTBTO statement discussing the Russian bolide, Pierrick Mialle, an acoustic scientist for the group said:? "We saw straight away that the event would be huge, in the same order as the Sulawesi event from 2009. The observations are some of the largest that?CTBTO's infrasound stations?have detected."

The Russian meteor blast picked up by the detectors is not a single explosion, Mialle said. Rather, it is burning, traveling faster than the speed of sound. "That's how we distinguish it from mining blasts or volcanic eruptions," he said.

Mialle said that scientists around the world will be using the CTBTO's data to better gauge the object's breakup and discern more about the object's final altitude, energy released and how the meteor disintegrated.

Micropressure changes

There are currently 45 infrasound stations in the CTBTO's network that measure micropressure changes in the atmosphere generated by infrasonic waves. Infrasound is one of the technologies used in the CTBTO?s network of sensors to monitor the globe for violations of the?Comprehensive Nuclear-Test-Ban Treaty?that bans all nuclear explosions.

Infrasound has been used as part of the CTBTO's tools to detect atomic blasts since April 2001 when the first station came online in Germany. Data from the stations is sent in near real time to Vienna, Austria, for analysis at the CTBTO?s headquarters. Both the raw and analyzed data are provided to all Member States of the CTBTO.

CTBTO Member States have spent $1 billion on setting up the CTBTO verification regime.

Just days before the meteor explosion over Russia, the CTBTO's seismic network detected a seismic event in North Korea. That event on Feb. 12 measured 4.9 in magnitude. Later that morning, North Korean officials announced that the country had conducted a nuclear test. The event was registered by 94 seismic stations and two infrasound stations in the CTBTO's network.

Leonard David has been reporting on the space industry for more than five decades. He is former director of research for the National Commission on Space and a past editor-in-chief of the National Space Society's Ad Astra and Space World magazines. He has written for SPACE.com since 1999.

Copyright 2013?SPACE.com, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Source: http://rss.csmonitor.com/~r/feeds/csm/~3/Ed5PcRd996Y/Russia-meteor-triggered-nuclear-warning-system

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Talk of peace with Pakistan Taliban angers victims

In this Thursday, Feb. 21, 2012, photo, Pakistani student Hazratullah Khan, 14, who was injured in a car bombing on December 17, 2012 in Peshawar, poses for a picture in Peshawar, Pakistan. Hazratullah Khan's right leg was amputated below the knee after he survived a car bombing as he was on his way home from school. His response when asked whether peace talks should be held with the Taliban leaders who ordered attacks like the ones that maimed him is simple: Hang them alive. Slice their flesh off their bodies and cut them into pieces. (AP Photo/Muhammed Muheisen)

In this Thursday, Feb. 21, 2012, photo, Pakistani student Hazratullah Khan, 14, who was injured in a car bombing on December 17, 2012 in Peshawar, poses for a picture in Peshawar, Pakistan. Hazratullah Khan's right leg was amputated below the knee after he survived a car bombing as he was on his way home from school. His response when asked whether peace talks should be held with the Taliban leaders who ordered attacks like the ones that maimed him is simple: Hang them alive. Slice their flesh off their bodies and cut them into pieces. (AP Photo/Muhammed Muheisen)

In this Saturday, July 7, 2102, photo, Pakistani daily worker Mufeed Ali, 48, who was injured by a remote control bomb at Lahore train station, on April, 24, 2012, reacts while posing for a picture in Lahore, Pakistan. Hazratullah Khan's right leg was amputated below the knee after he survived a car bombing as he was on his way home from school. His response when asked whether peace talks should be held with the Taliban leaders who ordered attacks like the ones that maimed him is simple: Hang them alive. Slice their flesh off their bodies and cut them into pieces. (AP Photo/Muhammed Muheisen)

In this Thursday, Aug. 2, 2012, photo, Pakistani Kawthar Javaid, 42, who was injured by a remote control bomb in Faisalabad in 2005, poses for a picture in Rawalpindi, Pakistan. Hazratullah Khan's right leg was amputated below the knee after he survived a car bombing as he was on his way home from school. His response when asked whether peace talks should be held with the Taliban leaders who ordered attacks like the ones that maimed him is simple: Hang them alive. Slice their flesh off their bodies and cut them into pieces. (AP Photo/Muhammed Muheisen)

In this Friday, July 27, 2012, photo, Pakistani Gani Abdul Rahman, 32, who was injured on July, 17, 2007, by a bomb blast in Islamabad, poses for a picture in Islamabad, Pakistan. Hazratullah Khan's right leg was amputated below the knee after he survived a car bombing as he was on his way home from school.(AP Photo/Muhammed Muheisen)

HOLD FOR A STROY SLUGGED PAKISTAN TALIBAN'S VICTIMS BY ASIF SHAHZAD, In this Thursday, July 12, 2012, photo, Pakistani student Yaseen Azizul Rahman, 19, who was injured in 2007 by a remote control bomb in Peshawar, poses for a picture, in Peshawar, Pakistan. To many victims of Taliban violence, the idea of negotiating with people responsible for so much human pain is abhorrent. Their voices, however, are rarely heard in Pakistan, a country where people have long been conflicted about whether the Taliban are enemies bent on destroying the state or fellow Muslims who should be welcomed back into the fold after years of fighting.(AP Photo/Muhammed Muheisen)

(AP) ? Hazratullah Khan, who lost his right leg below the knee in a car bombing, answers immediately when asked whether the Pakistani government should hold peace talks with Taliban leaders responsible for attacks like the one that maimed him.

"Hang them alive," said the 14-year-old, who survived the explosion on his way home from school. "Slice the flesh off their bodies and cut them into pieces. That's what they have been doing to us."

Khan, who is from the Khyber tribal region, pondered his future recently at a physical rehabilitation center in Peshawar.

"What was my crime that they made me disabled for the rest of my life?" he asked as he touched his severed limb.

In recent weeks, the Pakistani government and Taliban forces fighting in northwestern tribal areas have expressed an interest in peace talks to end the years-long conflict. An estimated 30,000 civilians and 4,000 soldiers have died in terrorist attacks in Pakistan since Sept. 11, 2001 ? many at the hands of the Pakistani Taliban.

To many victims of Taliban violence, the idea of negotiating with people responsible for so much human pain is abhorrent. Their voices, however, are rarely heard in Pakistan, a country where people have long been conflicted about whether the Taliban are enemies bent on destroying the state or fellow Muslims who should be welcomed back into the fold after years of fighting.

The Associated Press spoke with victims of terrorist attacks in Peshawar, Lahore, Karachi, Quetta and the tribal areas and their families to find out how they felt about negotiating peace with the Taliban.

Khan's classmate, Fatimeen Afridi, who was also injured in the same bombing in Khyber, said he would be happy to see negotiations with the militants ? but only after those who maimed him were punished. Afridi's left leg was amputated below the knee, shattering his dream of becoming a fast bowler on Pakistan's cricket team.

"If I find them, I will throw them in a burning clay oven," he said.

The push for peace talks gained momentum in December when the leader of the Pakistani Taliban offered to negotiate. The government responded positively, and even hinted that the militants would not need to lay down their weapons before talks could begin. That would be a reversal of the government's long-held position that any talks be preceded by a ceasefire.

So far, there have been few concrete developments, and it's unclear whether Pakistan's powerful military supports negotiations.

Skeptics doubt the militants truly want peace and point to past agreements with the Taliban that fell apart after giving militants time to regroup. Others say negotiations are the only option since numerous military operations against the Taliban have failed.

The biggest question ? especially for many of the Taliban's victims ? is whether the Taliban will have to pay any price for the people they are believed to have killed and wounded. The government hasn't said whether it would offer the Taliban amnesty for past offenses.

Many of the victims feel forgotten, saying no one has asked their opinion about holding peace talks. They have to fight for what little health care they can obtain, and there's almost no assistance for dealing with psychological trauma caused by the attacks.

Dr. Mahboob-ur-Rehman runs a private medical complex in Peshawar, a large facility that houses a prosthetic workshop and a therapy school, where both Khan and Afridi are being treated. Rehman said the Pakistani army has a state-of-the-art facility to treat its soldiers while there is little help for civilians. He estimated that roughly 10,000 civilians have been permanently disabled after losing limbs in Pakistani Taliban attacks.

In the southern city of Karachi, 12-year-old Mehzar Fatima was shot in the back when a gunman killed her father, a Shiite Muslim. The sectarian groups often accused of carrying out such attacks are closely aligned with the Pakistani Taliban. The gunshot left her unable to move her legs and feet and she fears she might never use them again.

Her mother, Kishwar Fatima, said she's being pressured to leave the hospital where the girl is being treated because there's no government assistance to help pay her bills.

Those wounded in the violence feel further victimized because many Pakistanis don't even agree on who is to blame for their suffering.

Despite the huge loss of life and property, the views of many Pakistanis are influenced by right-wing, anti-American propaganda that spawns conspiracy theories about the terrorist attacks. Fellow Muslims could never commit acts of violence against their own people, they say, so someone else must be to blame. Some theories suggest U.S. and Indian intelligence agencies support the Taliban and other militant groups to destabilize Pakistan.

Some people who support the militants think the Taliban are better than many of Pakistan's corrupt politicians who have failed to deliver good governance. Many Pakistanis also say the militant problems in the tribal areas are a result of the U.S. military presence in Afghanistan and when the U.S. leaves, the Pakistani Taliban will also stop fighting.

Even some of the victims aren't sure who is to blame.

The Taliban claimed responsibility for a Feb. 2 suicide attack that killed 23 people in the northwestern city of Lakki Marwat. But Mohammad Shafi, whose 24-year-old son was among nine soldiers killed in the explosion, isn't convinced the attackers were members of the Taliban. He says Muslims would never hurt a fellow Muslim.

Instead, Shafi thinks his son ? a boxer who never lost a fight before he was shot seven times during the attack on an army post ? was killed by Hindu agents that archrival India sent, with U.S. assistance, to destabilize Pakistan. He said Pakistan should sever ties with the U.S. to abolish terrorism.

"If my son was killed by infidels, he has been martyred and will go to heaven," he said.

Confusion over who is responsible for the deadly violence also has some victims wondering if the Pakistani government makes peace with the Taliban, will it also make peace with other militant groups.

Will the government, for instance, hold talks with Lashkar-e-Jhangvi, a group linked to al-Qaida that is accused of killing more than 175 Shiite Muslims during the past two months in the southwestern city of Quetta?

Ghazanfar Ali lost his 24-year-old son in one of these attacks on Jan. 10 in Quetta. Another of his sons survived the same attack after three major surgeries.

Ali broke down in tears as he recalled sifting through rubble and identifying his son's body by the ring he had on his finger because his head and face were wounded beyond recognition.

"There can't be peace with the Taliban," he said. "They slaughter a son in front of his father and then chant 'God is great!'"

__

Associated Press writers Riaz Khan and Rasool Dawar in Peshawar; Zaheer Babar in Lahore; Abdul Sattar in Quetta; and Adil Jawad in Karachi, Pakistan contributed to this report.

Associated Press

Source: http://hosted2.ap.org/APDEFAULT/3d281c11a96b4ad082fe88aa0db04305/Article_2013-02-23-Pakistan-Taliban's%20Victims/id-e6827998eac649378590feb2d5c1f759

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Saturday, February 23, 2013

Fishermen follow instincts to rescue 2 girls

PORTLAND, Ore. (AP) ? As their mother lay dead in the middle of the night, a 4-year-old Oregon girl dragged her seriously injured younger sister from a crashed car and the two huddled under a blanket ? and waited.

With the mangled car stuck deep in the woods, and no skid marks on the highway, the crash site was nearly impossible to detect.

In fact, authorities estimate the sisters were alone in the frigid woods for several hours early Wednesday as many motorists passed it by.

The children finally got help after two commercial fishermen spotted what appeared from a distance to be a basketball-sized gash in an alder tree along State Highway 401 between Astoria, Ore., and Naselle, Wash. Kraai McClure and Scott Beutler travel the two-lane road frequently, and had a gut feeling something was wrong.

The men slowed down, discussed the situation and decided to turn around and go take a look. McClure said he called 911 to see if there had been any reports of a wreck during the night. There weren't.

Beutler, who was a first responder when he lived in Mississippi, went into the brush and signaled McClure to alert authorities.

"I don't know exactly what told us to turn around, but I'm just really thankful we did," McClure said Thursday.

The men spotted the wrecked car a few hundred feet from the road. Nearby were the two young girls, scared and confused. "They could say their names but were totally in shock," McClure said.

The Washington State Patrol said the girls' mother, 26-year-old Jessica Rath of Astoria, probably was asleep when she veered off the road and struck the tree shortly after midnight. She died at the scene.

McClure and Beutler discovered the crash site around 8:30 a.m.

The 2-year-old, who had serious leg injuries, was flown to a Portland hospital. The 4-year-old was treated at an Astoria hospital and released.

An Oregon Health & Science University spokeswoman confirmed that the younger sister, Lylah Huff, was at Doernbecher Children's Hospital. The girls' father, Keaton Huff, declined interview requests Thursday and asked the hospital not to release his daughter's condition.

Trooper Russ Winger said investigators believe the 4-year-old, Aryanna Huff, pulled her sister from the vehicle and helped her to a spot about 20 feet away, where the fishermen found them. Winger said keeping warm with the blanket was vital with temperatures in the low 40s.

"Hypothermia sets in very quickly with something like that," Winger said. "They could have very well not been found and died of exposure."

Winger described the fishermen as heroes for acting on their hunch. McClure, however, gave the credit to Aryanna for helping Lylah out of the car and keeping her warm.

"She saved her sister," McClure said. "She was sharp enough. I don't know how she did it or anything else, but something was watching over those little girls."

"It was amazing that the little 4-year-old ? I have a little 4-year-old, too, she's almost 5 ? was able to get her little sister out and do that," he added. "It just blows my mind that she could do that in that situation. I don't know if she waited until morning, when they could see, but, you know, it just makes me want to cry."

Winger said investigators have yet to determine how fast Rath was driving, or whether there were any other factors in the crash. The crime blotter in the Jan. 26 edition of The Longview Daily News indicates Rath was sentenced to 10 days in jail for heroin possession and third-degree theft.

Source: http://news.yahoo.com/fishermen-acting-gut-crash-2-girls-220529931.html

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Oscar Pistorius bail hearing nearing decision

PRETORIA, South Africa (AP) ? A magistrate may rule Friday in Oscar Pistorius' bail hearing, deciding if the double-amputee athlete can be freed before trial or if he has to remain in custody over the shooting death of Reeva Steenkamp.

The prosecution was expected to complete its arguments opposing bail as the hearing, which should have been completed Wednesday, goes into a fourth day.

Pistorius is charged with one count of premediated murder over the Feb. 14 killing of Steenkamp. He says the shooting was accidental because he thought there was a dangerous intruder inside his home.

Pistorius' coach, Ampie Louw, says he's considering putting Pistorius back in training if he's bailed to allow him to "get his mind kind of clear."

Chief Magistrate Desmond Nair will decide if Pistorius is freed with conditions.

Source: http://news.yahoo.com/oscar-pistorius-bail-hearing-nearing-decision-073333252--oly.html

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Metal Gear Rising out now in Japan and Europe

I haven't commented in a couple days, been busy playing this game. Just finished it and WOW. This game has so many visually badass moments. There is never a cutscene where you say "I wish I could play that" you pretty much play it all. I'm really happy Kojima passed the development to P* this game wouldn't have been the samewithout them. Japan / Europe Enjoy! if anyone reading is on the fence about getting it. Get off the fence! pick it up

Source: http://n4g.com/news/1178212/metal-gear-rising-out-now-in-japan-and-europe

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Friday, February 22, 2013

Filmmaker fights AIDS his way ? Region ? Traverse City Record-Eagle

TRAVERSE CITY ? Max Fisher has a problem.

About two years ago, the Traverse City filmmaker began an AIDS documentary that focuses on the young generation of AIDS activists, but he can?t seem to turn off the camera. Their stories are just too compelling.

?The producer is telling me I need to stop, and I say, ?No. I have to keep recording these amazing stories,? he said. ?If they don?t make it in the movie, they?ll make it somewhere else.?

But at some point, it will be time to ?shut up and edit,? Fisher said.

Fisher has taken the lead of his activist mom, Mary Fisher, who recently appeared on the Today Show to talk about her newest and sixth book, ?Messenger: A Self Portrait.?

Fisher tells her story through the promise she made in her famous speech at the Republican National Convention in 1992: ?I want my children to know that their mother was not a victim. She was a messenger.?

Her poignant, 13-minute speech turned the image of AIDS on its head. Here was a classic beauty and daughter of a prominent Republican family. She worked as the first woman ?advance man? in the Gerald Ford White House. But Mary learned she had contracted AIDS from her husband, whom she divorced in 1991.

She pleaded for a more compassionate world unafraid to say the word AIDS.

?I will not hurry to leave you, my children,? she said. ?But when I go, I pray that you will not suffer shame on my account.?

Max, four at the time, said his mom was prepared to die, but shielded him and his brother from a sense of pending doom. As it turns out, the development of antiretroviral therapies has allowed her a long life.

AIDS awareness became her life?s cause. Her latest message: AIDS medications can?t help the hundreds of thousands who can?t afford them or tolerate the side effects. And there is still no cure. The World Health Organization reported close to 2 million died in 2010.

Max and his brother tested negative for H.I.V., yet lived with its reality every day. Max said his mother was honest about the disease, but never made him fearful.

Mary never thought she?d see Max get married, and breast cancer last year complicated the picture. But last September, she witnessed his marriage vows to Susan Borke.

Max fondly regards Borke as his ?voice of reason? and biggest supporter for FishSoup Films, his full-service film production company. Michael Moore brought the couple together. Fisher worked post-production on Moore?s film, ?Capitalism: A Love Story.? Borke works as an executive assistant for the Traverse City Film Festival, which Moore co-founded.

Max said his mother enthusiastically supports his documentary, yet he is realistic. His mom?s speech was seen by 27 million people. A documentary on pain and dying just won?t have the same pull, he said.

?I don?t ever expect to shine as much as she does,? he said. ?But if I can make even a small impact in one area, I?m happy with that.?

There are still many young people who struggle with shame, particularly those who live in the Bible Belt.

?They don?t want to be ostracized by their church and family so they shrivel up and die, without getting tested,? he said.

?

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Source: http://record-eagle.com/local/x1746091211/Filmmaker-fights-AIDS-his-way

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