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Showing posts from January 18, 2013

Novel Solar Photovoltaic Cells Achieve Record Efficiency Using Nanoscale Structures

Here's how to make a powerful  solar cell from indium and phosphorus: First, arrange microscopic flecks of gold on a semiconductor background. Using the gold as seeds, grow precisely arranged wires roughly 1.5 micrometers tall out of chemically tweaked compounds of indium and phosphorus. Keep the nanowires in line by etching them clean with hydrochloric acid and confining their diameter to 180 nanometers. (A nanometer is one billionth of a meter.) Exposed to the sun, a solar cell employing such nanowires can turn nearly 14 percent of the incoming light into electricity—a new record that opens up more possibilities for cheap and effective  solar power . According to  research published online in  Science —and validated at Germany's Fraunhofer Institute for Solar Energy Systems—this novel nanowire configuration delivered nearly as much electricity as more traditional indium phosphide  thin-film solar cells  even though the nanowires themselves covered only 12 percent of the d

Cassini Spacecraft Reveals Unprecedented Saturn Storm

A true-color image captured by Cassini in February 2011 shows the head of the storm overtaking the fainter, turbulent tail. Credit: NASA/JPL-Caltech/SSI Just as regions of our planet have monsoon season, or tornado season, so too does Saturn have  its own stormy season . Once every Saturn year or so—which corresponds to roughly 30 Earth years—a giant, churning storm works its way through  the clouds  of Saturn’s northern hemisphere, sometimes encircling the entire planet like a belt. Lasting a few dozen days or more, these storms have been documented as far back as 1876. The sixth giant Saturnian storm on record arrived a bit early, kicking off in late 2010, just 20 years after the previous storm. The timing proved fortuitous for planetary astronomers, who currently have a dedicated orbiter called Cassini  stationed at the ringed planet . And Cassini’s ringside seat, so to speak, has afforded the NASA spacecraft quite a show. A new study summarizing Cassini observations

Mainland reaffirms against US-Taiwan arms sales

BEIJING - A Chinese mainland spokesman on Wednesday reaffirmed the country's opposition to arms sales by the United States to Taiwan and urged the superpower to adhere to the one-China policy. "Our stance toward US arms sales, as you are clearly aware, is that we firmly oppose them," Yang Yi, spokesman for the State Council's Taiwan Affairs Office, told a press conference. Responding to a Taiwanese reporter's request for comment on Taiwan leader Ma Ying-jeou's recent intention to continue purchasing US weapons, Yang said, "We also hope that the US strictly abides by the three Sino-American joint communiques and the one-China policy." "Cross-Straits issues have to be eventually settled by Chinese living on both sides," Yang said. "We hope that both the mainland and Taiwan make joint efforts to create a new situation for the development of cross-Straits relations, and benefit compatriots and the Chinese nation." The People's Rep

Bitter winter blast hits the south hard

Cold snaps in southern China have triggered rising vegetable prices, disrupted transport and reignited debate over central heating, as He Na, Hu Yongqi and Zhang Yuchen report. Huang Hui, a 33-year-old English-language teacher at a Shanghai university, once had a coveted job as team leader with a multinational company in Beijing. She may have realized her ambition of becoming a project manager had it not been for her parents, who constantly reminded her it was time to get married and settle down. Clockwise from top: Workers remove ice from a cable in Weining county, Guizhou province. South China was hit by cold weather in early January, with the average price of vegetables rising continuously for 10 weeks. Residents try to clear ice from the street in Chenzhou, Hunan province. Tao Liang / Xinhua He Maofeng / for China Daily Zhan Yan / Xinhua Instead, Hui decided to leave the capital almost three years ago to pursue an academic career, living a quiet but independent lifestyle. However,

No deal seen clinched in UN nuke talks with Iran

(Agencies) VIENNA/DUBAI - The UN nuclear watchdog and Iran appear to have failed again in talks this week to finalise a deal to unblock an investigation into suspected atom bomb research in the Islamic state, a diplomatic source said on Thursday. The UN International Atomic Energy Agency (IAEA) and Iran were expected to hold a further meeting on February 12, following two days of negotiations in Tehran that ended on Thursday, the source added, giving no further details. The apparent absence of a breakthrough in the January 16-17 discussions in the Iranian capital signalled a new setback for efforts to allay mounting international concern over Tehran's atomic aims and help avert the threat of a new Middle East war. The Vienna-based UN agency had hoped to clinch an elusive framework agreement with Iran that would allow the IAEA to resume a long-stalled inquiry into suspected military dimensions to the country's nuclear program. The IAEA, whose mission is to prevent the spread of

Lithium batteries central to Boeing's 787 woes

Lithium batteries that can leak corrosive fluid and start fires have emerged as the chief safety concern involving Boeing's 787 Dreamliner, a problem that apparently is far more serious than government or company officials acknowledged less than a week ago. The Federal Aviation Administration late Wednesday grounded Boeing's newest and most technologically advanced jetliner until the risk of battery fires is resolved. The order applies only to the six Dreamliners operated by United Airlines, the lone U.S. carrier with 787s. But other airlines and civil aviation authorities in other countries will be under pressure to follow suit or face possible accusations of taking unnecessary risks with public safety. Japan's two largest air carriers voluntarily grounded their 787s on Wednesday ahead of the FAA's order following an emergency landing by one of the planes in Japan. The Indian government ordered Air India to ground its fleet of six Boeing 787 aircraft. That means more t

Amateur prospector finds 5kg gold nugget

MELBOURNE: An amateur prospector has made the find of a lifetime in southern Australia, unearthing a gold nugget weighing about five kilograms (11 pounds) just outside the town of Ballarat, reports said yesterday. The Y-shaped deposit was found with a hand-held metal detector at a depth of a little over 60 centimetres (24 inches), according to a video of the find posted on YouTube. "The prospector said it sounded like the bonnet of a car through the headphones," wrote TroyAurum, who uploaded the video. "It was lying flat (broad side up) and he carefully dug it up." The find, made on Wednesday at a popular prospecting site outside Ballarat 110 kilometres from Melbourne, was confirmed by the owner of the town's gold shop, Cordell Kent. "A lot of people think Victoria's goldfields are dead and that there's none left, but he (the prospector) has worked in an area where a lot of people have worked in the past but he persisted and he's been rewarded,&

30 hostages killed as Algeria crisis ends

ALGIERS: Thirty hostages were killed last night when Algerian forces stormed a remote desert gas plant occupied by militants in retaliation for French intervention in Mali, an Algerian security official said. Of these, eight were Algerians and seven were foreigners, including two British, two Japanese and a French national. Some eight hours after the army assault began, the Algerian state media said it was over. At least 11 militants including their leader were killed in the operation. Two Algerians, including the group's leader Tahar Ben Cheneb, a prominent commander in the region, were among the dead, along with three Egyptians, two Tunisians, two Libyans, a Malian and a French citizen. Western leaders expressed anger they had not been consulted before the operation and scrambled for word of their citizens. Algeria said its troops had been forced to act to free them due to the "diehard" attitude of their captors. Al Qaeda-linked militants seized the Ain Amenas installat

Afghanistan: My Enemy's Enemy

Will a local anti-Taliban revolt in the south affect the future course of the country when NATO forces exit in 2014? In the summer of 2012, something remarkable appeared to be happening in Afghanistan; something that both the central government and its NATO backers had been hopeful of for more than a decade – an uprising against the Taliban by local people. Over a few weeks in the Andar district of Ghazni province, about 150km south of Kabul, the inhabitants managed to do what NATO and the Afghan army had failed to do in years; they kicked their former overlords out of their own backyard. The revolt was hailed by some optimistic Western observers as a turning point in the long struggle against the Taliban, so far-reaching in its implications that it might even determine what happens nationwide after US troops withdraw in 2014. Others have since been more sceptical, arguing that all was not as it seemed. The 'uprising' was really just one faction fighting against another, said

US officially recognises Somalia government

The United States has recognised Somalia's government for the first time in more than two decades. Hillary Rodham Clinton, the US secretary of state, made the announcement on Thursday alongside Somali President Hassan Sheikh Mohamud. President Barack Obama was reported by the AP news agency as having met privately with the Somali leader at the White House. Washington had not recognised a Somali government since warlords toppled dictator Mohamed Siad Barre in 1991. American intervention failed two years later after militants shot down two US helicopters and killed 18 American servicemen. Clinton said times have changed, citing the armed group al-Shabab's retreat from every major Somali city. The US provided $780m to African forces to help that effort. The White House also expressed optimism about Somalia's future and pledged to work with the country's new government to promote peace and security, improve the economy and boost social services. Obama also urged his Somali

Lawyer of Afghan massacre suspect claims PTSD

US soldier charged with killing 16 Afghans suffered brain injuries and post-traumatic stress disorder, say defence team. A US soldier charged with capital murder in the slayings of 16 civilians near his military post in Afghanistan was diagnosed as suffering from post-traumatic stress disorder (PTSD) and traumatic brain injury prior to the killings, his lawyer has claimed. The disclosure that Robert Bales was diagnosed with PTSD followed a hearing on Thursday in which defence lawyers told a military judge they were preparing a possible "mental health defence". Prosecutors are seeking the death penalty against Bales, a decorated veteran of four combat tours in Iraq and Afghanistan who is accused of gunning down the villagers, mostly women and children, in cold blood during two rampages through their family compounds in Kandahar province in March of last year. The judge, Colonel Jeffery Nance, said such a defence would require a formal psychiatric evaluation and he would orde

Uncertainty over missing Algeria hostages

Fate of hostages unclear after reports that at least 30 were killed in military operation that ended a 36-hour standoff. At least 30 hostages and 11 members of an al-Qaeda-affiliated group were killed when Algerian forces stormed a desert gas plant to free the captives, drawing international attention to al-Qaeda in North Africa. Eight Algerians and seven foreigners, including two British, two Japanese and a French national, were among the dead, an Algerian security source said. Nine foreign nationals have been released but the fate of a number of those who had been held by the fighters remains unclear. Stephen McFaul from the Republic of Ireland is one of the nine foreign nationals released. The hostages included Algerians, as well as foreigners from at least nine countries - including the US, Britain and Japan. Japanese Prime Minister Shinzo Abe cut short a visit to Indonesia on Friday, reports said, to fly home and deal with the hostage crisis in Algeria in which numerous Japanese a