FILE - In this April 13, 2011 file photo, a Mattel's Hot Wheels car from the Larry's Garage Series is shown in Portland, Ore. Mattel Inc. said Tuesday, Jan. 31, 2012, strong holiday demand for toys including Barbie, Hot Wheels and American Girl helped push its fourth-quarter net income up 14 percent. (AP Photo/Rick Bowmer, File)
FILE - In this April 13, 2011 file photo, a Mattel's Hot Wheels car from the Larry's Garage Series is shown in Portland, Ore. Mattel Inc. said Tuesday, Jan. 31, 2012, strong holiday demand for toys including Barbie, Hot Wheels and American Girl helped push its fourth-quarter net income up 14 percent. (AP Photo/Rick Bowmer, File)
NEW YORK (AP) ? Strong holiday demand for toys including Barbie and Monster High dolls helped push Mattel Inc.'s fourth-quarter profit up a better-than-expected 14 percent.
The company also raised its dividend and its shares edged higher in premarket trading.
But there were a few lumps of coal in the report, as U.S. sales dipped and weakness continued at its Fisher-Price unit.
The holiday quarter is crucial for toy makers, who can make up to half of their annual sales during the period.
Mattel, which is the No. 1 U.S. toy maker, reported Tuesday that its net income rose to $370.6 million, or $1.07 per share, for the period ended Dec. 31. That's up from $325.2 million, or 89 cents per share, a year ago.
This beat the $1 per share that analysts polled by FactSet expected.
"Mattel delivered another strong year, our third consecutive year of solid performance, which I am especially pleased about given the soft global economic backdrop and the highly promotional environment, particularly in the U.S.," CEO Bryan G. Stockton said in a statement.
Mattel's quarterly revenue edged up 1 percent to $2.15 billion from $2.12 billion. But that missed Wall Street's estimate of $2.22 billion.
A 2 percent drop in U.S. sales was offset by stronger results overseas, where revenue rose 5 percent.
.Barbie sales rose 6 percent in the quarter. Sales of for Mattel's Wheels segment ? which includes the Hot Wheels, Matchbox and Tyco R/Co brands ? increased 5 percent. American Girl sales rose 4 percent. But sales for Fisher-Price fell 10 percent. The Fisher-Price unit makes pre-school toys such as Power Wheels.
For the year, Mattel reported net income of $768.5 million, or $2.18 per share, up from $684.9 million, or $1.86 per share, a year earlier.
Annual revenue increased 7 percent to $6.27 billion from $5.86 billion.
Mattel, based in El Segundo, Calif., is also raising its annual dividend by 35 percent.
The toy maker will pay a first-quarter cash dividend of 31 cents per share on March 9 to shareholders of record on Feb. 23. Its annualized dividend is expected to be $1.24 per share. The prior-year's dividend was 92 cents per share.
The company said that its $680 million acquisition of HIT Entertainment, the company behind Thomas the Tank Engine and Bob the Builder, is expected to close on Wednesday. Mattel announced the deal in October. It will be the company's biggest acquisition in a decade.
Mattel's chief rival, Hasbro Inc., reports its financial results on Monday.
MONDAY, Jan. 30 (HealthDay News) -- The U.S. Food and Drug Administration on Monday approved a drug to treat the most common form of skin cancer, basal cell carcinoma.
Erivedge (vismodegib) is the first drug sanctioned in the United States to treat basal cell skin cancer that has metastasized, or spread. The once-daily pill is also designed for cases deemed unsuitable for surgery or radiation, the agency said in a news release.
This usually slow-growing, painless form of cancer starts in the epidermis, the top layer of skin. Frequent exposure to sunlight and other forms of ultraviolet radiation are the typical causes, the FDA said.
Researchers evaluated the safety and effectiveness of Erivedge in a clinical study of 96 people with locally advanced or metastatic cancer. Of those with metastatic disease, 30 percent had at least a partial response to the drug, while 43 percent of people with locally advanced basal cell had at least a partial response.
One specialist welcomed the drug's approval.
"Eviredge is an amazing revolutionary approach to treating skin cancer," said Dr. Michele Green, dermatologist at Lenox Hill Hospital in New York City. "I have many patients who are elderly and infirm for whom getting surgery is a major ordeal. Molecular biology has advanced to the point where such an important advance in therapy was unthinkable even a few years ago."
Skin cancer is the most commonly diagnosed cancer in the United States, and it is estimated that one in five Americans will develop it in their lifetime. Caught early, it is highly treatable.
The most frequently cited side effects of Erivedge included muscle spasms, hair loss, weight loss, nausea, diarrhea, fatigue, distorted sense of taste, decreased appetite, constipation and vomiting.
Because of the potential risk for death or severe birth defects to a fetus, the drug will be packaged with a label warning, and doctors will not prescribe it to women who are pregnant, the agency said. Men and women will be advised to use birth control while taking the pills.
Erivedge, marketed by San Francisco-based Genentech, won expedited approval under a priority review program for drugs that may represent a major treatment advance.
More information
The Skin Cancer Foundation has details about basal cell.
Cuba's President Raul Castro, right, and Cuba's Vice-President Jose Ramon Machado Ventura attend the closing ceremony of the Communist Party Conference in Havana, Cuba, Saturday, Jan. 29, 2012. Cuba's Communist leaders vowed not to cede any ground to "the enemy," even as they pledged to fight corruption and continue overhauling the island's listing Marxist economy with an injection of free market reform. (AP Photo/Ismael Francisco, Prensa Latina)
Cuba's President Raul Castro, right, and Cuba's Vice-President Jose Ramon Machado Ventura attend the closing ceremony of the Communist Party Conference in Havana, Cuba, Saturday, Jan. 29, 2012. Cuba's Communist leaders vowed not to cede any ground to "the enemy," even as they pledged to fight corruption and continue overhauling the island's listing Marxist economy with an injection of free market reform. (AP Photo/Ismael Francisco, Prensa Latina)
Cuba's President Raul Castro speaks during the closing ceremony of the Communist Party Conference in Havana, Cuba, Saturday, Jan. 29, 2012. Cuba's Communist leaders vowed not to cede any ground to "the enemy," even as they pledged to fight corruption and continue overhauling the island's listing Marxist economy with an injection of free market reform.(AP Photo/Ismael Francisco, Prensa Latina)
Members of the Communist Party attend the closing ceremony of the Communist Party Conference in Havana, Cuba, Saturday, Jan. 29, 2012. Cuba's Communist leaders vowed not to cede any ground to "the enemy," even as they pledged to fight corruption and continue overhauling the island's listing Marxist economy with an injection of free market reform.(AP Photo/Ismael Francisco, Prensa Latina)
Members of Cuba's Communist Party raise their hands to approve the final document of the Communist Party Conference in Havana, Cuba, Saturday, Jan. 29, 2012. Cuba's Communist leaders vowed not to cede any ground to "the enemy," even as they pledged to fight corruption and continue overhauling the island's listing Marxist economy with an injection of free market reform. (AP Photo/Ismael Francisco, Prensa Latina)
HAVANA (AP) ? President Raul Castro delivered a full-throated defense of Cuba's one-party political system on Sunday, and a sharp warning to Communist Party delegates to fight corruption he said was a greater threat to the revolution than anything the United States could dream up.
In a stern closing speech to the party's national conference, Castro reiterated a pledge to institute term-limits for Cuban officials, saying a constitutional amendment would be required but that leaders should begin to adopt the practice even before it is formalized.
Castro has spoken previously about limiting high-ranking officials including himself to two, 5-year terms.
The U.S. threat to Cuba and the limits it placed on reform was a continuing theme of the speech. Cuba's president upbraided those who were hoping to see more fundamental changes come out of the two-day meetings ? or any new faces amid the aged upper ranks of the party and government hierarchy.
"There has been no shortage of criticism and exhortations by those who have confused their intimate desires with reality, deluding themselves that this conference would consecrate the beginning of the dismantling of the political and social system the revolution has fought for for more than half a century," he said.
The Cuban leader said those who want to see Cuba restore a multiparty system are forgetting that it is under siege from a Goliath to the north that would stop at nothing to destroy it.
"To renounce the principle of a one-party system would be the equivalent of legalizing a party, or parties, of imperialism on our soil," he said.
Castro was sharply critical of the United States' democratic system, which he said only concentrated power in the hands of the wealthy. He said that while Cuba had only one party, it sought the participation of all citizens through party and workplace meetings.
"We must promote democracy in our society, starting with the party," he said, urging rank-and-file members to speak up when they disagree with something.
The speech included denunciations of Washington's 50-year trade embargo, its support for dissidents and its imprisonment of Cuban agents who had infiltrated anti-Castro groups in Miami.
Castro also poured water on hopes that a new generation of Cuban politicians were any closer to the brass ring of power, saying the island remained without a backbench of young leaders.
The conference was presided over by the 80-year-old Castro and his 81-year-old chief deputy, Jose Ramon Machado Ventura. The island's third ranking leader, Ramiro Valdes, is 79.
Castro and his brother Fidel, now retired, have ruled Cuba since their 1959 revolution. There was no sign of the elder Castro at the confab, which was closed to foreign journalists.
Raul Castro has pushed a series of dramatic economic reforms since taking power in 2008, legalizing the sale of private homes and used cars, allowing hundreds of thousands to go into business for themselves, turning fallow government land over to small-time farms, and extending bank loans to entrepreneurs and others.
But many social and political reforms have not materialized. After promising in July to study changes to immigration laws that keep most Cubans from ever leaving the country, Castro told the nation in December that the time was not yet right, citing the continued threat from Washington.
At a Communist Party Congress in April, Castro and brother Fidel raised hopes that a new generation of leaders would soon appear on the horizon. Nine months later, there have been few visible changes.
A Cuban official told The Associated Press recently that despite the lack of movement among cabinet ministers and other senior leaders, many midlevel government posts have quietly changed hands, with younger officials moving up. The official spoke on condition of anonymity because he was not authorized to discuss the matter publicly, and his assertions could not be independently confirmed.
Castro spent a large part of his 40-minute speech warning delegates about the evils of corruption, saying graft was "the principal enemy of the revolution, much more damaging than the multimillion-dollar subversive and interfering programs of the U.S. government and its allies."
He said the Interior Ministry was in the midst of several high-profile investigations of graft and other violations, which would become known at the appropriate time.
"To win the battle against corruption we must first stop it and then liquidate it," Castro said. "We have warned that within the law, we will be implacable."
BEIJING ? A young man posts his photo with a leaflet demanding freedom for Tibet and telling Chinese police, come and get me. Protesters rise up to defend him, and demonstrations break out in two other Tibetan areas of western China to support the same cause.
Each time, police respond with bullets.
The three clashes, all in the past week, killed several Tibetans and injured dozens. They mark an escalation of a protest movement that for months expressed itself mainly through scattered individual self-immolations.
It's the result of growing desperation among Tibetans and a harsh crackdown by security forces that scholars and pro-Tibet activists contend only breeds more rage and despair.
That leaves authorities with the stark choice of either cracking down even harder or meeting Tibetan demands for greater freedom and a return of their Buddhist spiritual leader, the Dalai Lama ? something Beijing has shown zero willingness to do.
"By not responding constructively when it was faced with peaceful one-person protests, the (Communist) party has created the conditions for violent, large-scale protests," said Robbie Barnett, head of modern Tibetan studies at New York's Columbia University.
This is the region's most violent period since 2008, when deadly rioting in Tibet's capital Lhasa spread to Tibetan areas in adjoining provinces. China responded by flooding the area with troops and closing Tibetan regions entirely to foreigners for about a year. Special permission is still required for non-Chinese visitors to Tibet, and the Himalayan region remains closed off entirely for the weeks surrounding the March 14 anniversary of the riots that left 22 people dead.
Video smuggled out by activists shows paramilitary troops equipped with assault rifles and armored cars making pre-dawn arrests. Huge convoys of heavily armored troops are seen driving along mountain roads and monks accused of sedition being frog-marched to waiting trucks.
For the past year, self-immolations have become a striking form of protest in the region. At least 16 monks, nuns and former clergy set themselves on fire after chanting for Tibetan freedom and the return of the Dalai Lama, who fled to India amid an abortive uprising against Chinese rule in 1959.
China, fiercely critical of the Dalai Lama, says Tibet has been under its rule for centuries, but many Tibetans say the region was functionally independent for most of that time. Anger over cultural and religious restrictions is deepened by a sense that Tibetans have been marginalized economically by an influx of migrants from elsewhere in China.
In a change from the individual protests, several thousand Tibetans marched to government offices Monday in Ganzi prefecture in Sichuan province. Police opened fire into the crowd, killing up to three people, witnesses and activist groups said.
On Tuesday, security forces opened fire on a crowd of protesters in another area of Ganzi, killing two Tibetans and wounding several more, according to the group Free Tibet.
On Thursday in southwestern Sichuan province's Aba prefecture, a youth named Tarpa posted a leaflet saying that self-immolations wouldn't stop until Tibet is free, the London-based International Campaign for Tibet said. He wrote his name on the leaflet and included a photo of himself, saying that Chinese authorities could come and arrest him if they wished, group spokeswoman Kate Saunders said in an email.
Security forces did so about two hours later. Area residents blocked their way, shouting slogans and warning of bigger protests if Tarpa wasn't released, Saunders said. Police then fired into the crowd, killing a a 20-year-old friend of Tarpa's, a student named Urgen, and wounding several others.
The incident, as with most reported clashes in Tibetan areas, could not be independently verified and exact numbers of casualties were unclear because of the heavy security presence and lack of access. The topic is so sensitive that even government-backed scholars claim ignorance of it and refuse to comment.
The government, however, acknowledged Tuesday's unrest, saying that a "mob" charged a police station and injured 14 officers, forcing police to open fire on them. The official Xinhua News Agency said police killed one rioter and injured another.
"The Chinese government will, as always, fight all crimes and be resolute in maintaining social order," Foreign Ministry spokesman Hong Lei said in comments on the incident.
In a commentary Sunday, the nationalist tabloid Global Times repeated accusations that the protests were inspired by Tibetan exile groups and their demands were out of step with the desire for economic development.
Yet, it also conceded that the Dalai Lama retained considerable religious influence over Tibetans, warning this created a dangerous trend of "melding the political and relgious."
The harsh response points to a deep anxiety about the self-immolations, said Youdon Aukatsang, a New Delhi-based member of the Tibetan parliament-in-exile.
"They're worried that there is an underground movement in Tibet that is coming to the surface," she said.
Tibetan desperation has been fed both by the harsh crackdown ? security agents reportedly outnumber monks in some monasteries ? along with a deep fear that the Dalai Lama, probably the most potent symbol of Tibet's separate identity, will never return.
The 76-year-old Nobel Peace Prize laureate handed his political powers to an elected assembly last year. That was intended to ensure the Tibetan cause would live on after him, but was met with considerable anxiety among many Tibetans who saw it as a sign he was giving up his role as leader of their struggle.
Dibyesh Anand, a Tibet expert at London's University of Westminster, said resistance to Chinese rule is likely to grow more fierce.
"Protests will get more radicalized since the Tibetans in the region see no concession, no offer of compromise, no flexibility coming from the government," he said.
FILE- This Nov. 1, 2006 file photograph shows former Boston Mayor Kevin White outside Faneuil Hall in Boston Wednesday, Nov. 1, 2006. Former Mayor Kevin H. White, who led the city for 16 years including racially turbulent times in the 1970s, died Friday, a family spokesman said. He was 82. (AP Photo/Elise Amendola)
FILE- This Nov. 1, 2006 file photograph shows former Boston Mayor Kevin White outside Faneuil Hall in Boston Wednesday, Nov. 1, 2006. Former Mayor Kevin H. White, who led the city for 16 years including racially turbulent times in the 1970s, died Friday, a family spokesman said. He was 82. (AP Photo/Elise Amendola)
In this Tuesday, Nov. 3, 1970, Sen. Edward Kennedy, center, and his wife, Joan, left, greet Boston Mayor Kevin White and his wife, Kathryn White, at their Charles street polling place in Boston Mass. Former Boston Mayor Kevin White died Friday, Jan. 27, 2012. White was diagnosed with Alzheimer?s disease in 2003. A family spokesman says he died at home surrounded by family. He was 82. (AP Photo/Bill Chaplis)
In this, Wednesday, Nov. 1, 2006. file photo, former Boston Mayor Kevin White, center, laughs with current Mayor Thomas Menino, left, and former Mayor Raymond Flynn prior to the unveiling of a bronze statue bearing White's likeness outside Faneuil Hall near Quincy Market in Boston. White died Friday, Jan. 27, 2012. White was diagnosed with Alzheimer?s disease in 2003. A family spokesman says he died at home surrounded by family. He was 82. (AP Photo/Elise Amendola)
In this Wednesday, Nov. 1, 2006 file photo, former Boston Mayor Kevin White laughs with supporter Marie Ostiguy after the unveiling of a bronze statue bearing White's likeness outside Faneuil Hall near Quincy Market in Boston. White, who died Friday, Jan. 27, 2012, was diagnosed with Alzheimer?s disease in 2003. A family spokesman says he died at home surrounded by family. He was 82.(AP Photo/Elise Amendola)
BOSTON (AP) ? Kevin H. White, a four-term mayor who led Boston through years of racial violence and economic stagnation and was credited with putting the city on a path to prosperity, has died. He was 82.
White, who had been diagnosed with Alzheimer's disease in 2003, died Friday night at his Beacon Hill home surrounded by his family, said George Regan, a family spokesman and friend.
"He was a man who built Boston into the world-class city it is today," said Regan, who called his loss "devastating."
White, a white Irish Catholic from a family of politicians, is credited with revitalizing Boston's downtown and seeing the city through court-ordered busing, but he ended his tenure in 1983 under a cloud of ethics suspicions.
The Democrat was elected Massachusetts secretary of state three times before running for mayor for the first time in 1967 against antibusing activist Louise Day Hicks. He defeated her with support from the black community and liberals.
After losing a 1970 bid for governor, White was re-elected mayor in 1971, again defeating Hicks. He won again narrowly in 1975 and 1979.
White was considered as a vice presidential running mate to U.S. Sen. George McGovern of South Dakota in 1972 but was passed over for U.S. Sen. Thomas Eagleton of Missouri, who was later cast aside for R. Sargent Shriver Jr.
After U.S. District Court Judge W. Arthur Garrity ordered busing to desegregate public schools in 1974, White protected schoolchildren from ensuing violence with federal and state assistance during the period of crisis and in 1976 led a march of 30,000 to protest racial violence.
White was never totally comfortable with busing, however, and called Garrity's plan "too severe."
"I wish I knew a way to have taught Garrity or convinced Garrity to be more generous ... or softer in his implementation of that order," White said after his time as mayor.
U.S. Sen. John Kerry of Massachusetts, a fellow Democrat, said White "knew how to wisely wield the power of the mayor's office for the public good."
"For 16 years," Kerry said in a statement, "the mayor shepherded the city through the turbulence of the late '60s and mid-'70s and in the process ushered in the remarkable city we know today."
Current Mayor Thomas Menino, also a Democrat, praised White for his contributions to the city.
"Mayor Kevin White was a great friend and a great leader who left a lasting mark of hope and inspiration on the City of Boston," he said in a statement. "He will be sorely missed."
White's first two terms were known for his Little City Halls in the city's far-flung neighborhoods that gave power to ethnic and racial minorities, but he consolidated his power in his final two terms.
White closed the Little City Halls and instead used a network of ward lieutenants who rewarded the mayor's supporters with city jobs and contracts.
Seven mayoral aides were eventually indicted on fraud and extortion charges. His one-time budget director and an official of the Boston Redevelopment Authority were convicted of fraudulently obtaining city pensions. A deputy commissioner was convicted of tax evasion for failing to report money that prosecutors said he gained from bribes.
White was never implicated. The State Ethics Commission, however, conducted a 10-month investigation that found "reasonable cause" that White had violated conflict-of-interest laws.
The city also wallowed in a financial crisis in the later years of his tenure that led to layoffs of police officers and firefighters and the shutdown of some stations.
The crises were exploited by his critics, who called him King Kevin, and he dropped out of the 1983 mayoral race, eventually won by Raymond Flynn.
"It's no secret that Kevin and I were rivals for many years," Flynn said in a statement. "But underneath that sometimes heated rivalry, rooted in different priorities, was a mutual respect. Kevin and I shared a deep love for this complex, fascinating city of Boston."
A liberal reformer, White appealed to a cross-section of society, including the young.
Once, when the Rolling Stones were arrested on the way to Boston, the mayor released them into his own custody.
"The Stones have been busted, but I have sprung them!" he told an audience at Boston Garden.
While the busing crisis stained Boston's image, White was also credited with revitalizing the city's downtown, especially the shops and restaurants of Quincy Market, which remains one of the city's top tourist attractions. He thought the downtown renaissance would make Boston a "world-class city."
A statue of White was unveiled near Quincy Market in 2006.
Gov. Deval Patrick, a Democrat, said White's stewardship created "a path to prosperity for the city."
White's father and maternal grandfather had been Boston City Council presidents. In 1956, he married Kathryn Galvin, the daughter of another City Council president. He was educated at Tabor Academy, Williams College, Boston College Law School and the Harvard Graduate School of Public Administration.
After handing over the office to Flynn in 1984, White accepted a position at Boston University as a professor of communications and public management.
While mayor in 1970, White had major surgery to remove two-thirds of his stomach. He suffered a heart attack in 2001 while at a Florida restaurant and spent several days in a hospital when he had a pacemaker implanted.
He is survived by his wife of 55 years, Kathyrn Galvin White, five children and several grandchildren.
___
Associated Press Writer Sylvia Wingfield contributed to this report.
At this point in his career, it's safe to put John Earner in the "names as destiny" category. Following a hugely successful run with Playfish, he's leaving the social game developer today to start as an entrepreneur in residence at Accel, according to?sources. A former naval officer, he joined as the company in 2008 as its first game producer, where he shepherded the development of its first big simulation game, Pet Society. Having figured out how to monetize virtual goods with it, he went on to launch the company's next big hit, Restaurant City.
STATE COLLEGE, Pa. ? For decades, Joe Paterno was the public face of Penn State. For almost as long, his near-constant companion, wife Sue, seemingly wielded as much influence.
As tributes flowed this week for the late Hall of Fame coach, the extent of Sue Paterno's sway on her husband, the football program and the university became obvious, for those watching in or outside of Happy Valley.
She served as a host to potential recruits at the family home, a tutor to players, a counselor to concerned parents who entrusted their football-playing sons to her husband, and a prodigious fundraiser for the university and charitable organizations.
While a bronze statue outside Beaver Stadium memorializes the legacy of the winningest coach in major college football, it was Sue Paterno who was her husband's rock.
"For my dad, he never doubted my mother," their son Jay said at Thursday's memorial service for his father. "My mother had it all and continues to have it all. He could do his job and we could share him with Penn State because he knew my mother was in complete command on the home front."
Through the recent months of scandal that engulfed the university and a week's worth of private and public memorials for Penn State's longtime coach, other lasting images of Sue Paterno have emerged:
_She showed her spunk by coming to her husband's defense with a quick callback to a trustee after Joe Paterno was unceremoniously fired via a phone call. "After 61 years he deserved better," Sue Paterno said according to The Washington Post. Then, she hung up.
_A short time after being dismissed, she stood arm in arm with her husband as they stepped outside their modest State College home and greeted hundreds of well-wishers.
_And at the end of an emotional week in State College, Sue Paterno appeared composed, only occasionally fighting back tears, with her arms around some of her grandchildren as about 12,000 people gathered for public memorial. She rose from her seat and joined in a standing ovation as speakers defended his legacy against criticism that he failed to do more when told about an alleged child sexual assault involving one of his former assistants.
The Paternos were about as close to royalty as you can get in Happy Valley ? a modest first family of college football.
"They went everywhere together," former quarterback Daryll Clark said this week. "They were one and one."
Joe Paterno died Sunday at age 85, less than three months after being diagnosed with lung cancer.
"Joe Paterno indeed had an indomitable will with one exception: when his will ran counter to that of his wife and my mother," Jay Paterno said in a light moment from the memorial service for the man who became lovingly known around town as "JoePa."
Save for a few moments, 71-year-old Sue Paterno looked composed for a widow who just lost her husband under already emotional circumstances. Their family announced Paterno had been diagnosed with cancer just 10 days after he was ousted on Nov. 9 as Penn State coach following 46 seasons.
Sue and Joe Paterno were side by side on the family's front walk the night of the dismissal as he tried to console fans upset that he had been fired in the aftermath of child sex abuse charges against retired assistant Jerry Sandusky.
She joined the rest of the crowd at the memorial service giving Phil Knight a standing ovation after the Nike founder and CEO gave the most impassioned defense yet of her husband's legacy in the wake of the firing.
Appearing to nearly tear up at times, she otherwise looked poised during the emotional service that included several video tributes to Paterno, who amassed 409 victories.
Despite their recognition, they led lives similar to others who worked at Penn State. They raised five children in a ranch home next to a local park. There's no fence lining the front yard and no gates guarding the driveway.
The family's phone number is listed in the phone book. It was a way, Sue Paterno has said, for families of players to reach them in an emergency.
Besides tutoring players and helping to counsel players' parents, Sue Paterno was a prodigious fundraiser for the university library that bears the family's name ? it was, after all, where Joe and Sue met, when he was an assistant coach and she a freshman at the school.
He had a degree in English literature from Brown. She was an English student.
Outside of football, they rarely spent a moment apart.
"Besides Joe coaching and being at the football building, those two were inseparable," Clark said. He said the Paternos treated him as if he were one of their own children.
Sue Paterno baked spreads of cookies and desserts when the family hosted recruiting visits. Current and former players still rave about them.
At the memorial service, former receiver Kenny Jackson recounted a conversation Sue Paterno had with his family while he was being recruited. She reinforced the themes Joe Paterno promoted in his "grand experiment" of placing as much emphasis on academics as athletics.
"Sue only promised two things: the first, Kenny will go to class; second, he will get a quality education," Jackson said. "That's all she said. She never talked about anything else but my education. So I thank you Sue. ... You always made sure that was the first priority."
And she's responsible for perhaps one of the most lasting game-day memories of Joe Paterno.
Back in the late `60s, Sue Paterno suggested he raise the cuffs on his pants so mud wouldn't get on his wool slacks while coaching. It wasn't as much a concern when JoePa switched to his trademark khakis ? but Sue Paterno said her husband kept rolling them up anyway as a superstition.
"People don't realize how much she's done for this place," Joe Paterno said in an interview with The Associated Press in 2009. "I've said many times that they won't have any problems replacing me, but if they can find a coach's wife like Sue, they'll hit the jackpot."
The Paternos became renowned in the community for their generosity. They championed Special Olympics and THON, the Penn State student-organized dance marathon charity that raises millions of dollars annually for childhood cancer research and treatment.
They've contributed more than $4 million to the university during his tenure, including $3.5 million in 1998 to endow faculty positions and scholarships, and support two building projects.
Minus endorsements outside his university contract, Paterno made just more than $1 million a year, a relative bargain for a coach with two national championships.
Three years ago, the Paternos pledged $1 million to help build a new wing at Mount Nittany Medical Center, the State College hospital where Joe Paterno died Sunday.
There were no flowers or balloons in the room, Scott Paterno said ? not Joe's style. He suspected his mother had them redirected to other patients in the hospital.
Joe Paterno died less than three months after the emergence of the stunning scandal that led to his dismissal. University trustees ousted him Nov. 9, four days after charges were first filed against Sandusky. He is out on bail and awaiting trial after denying the allegations.
Paterno was a witness before a state grand jury investigating Sandusky, and authorities have said he was not a target of the probe. Paterno had testified he had relayed a 2002 abuse allegation passed on by a graduate assistant to campus superiors, fulfilling his legal obligation.
School trustees in recent weeks have cited, in part, Paterno's failure to fulfill a moral duty to tell police outside the university as a reason for his dismissal.
A tenure of more than six decades with the football program, including 15 years as an assistant before being promoted to head coach, had come to an end in early November. The cancer diagnosis came several days later.
Sue Paterno was constantly at her husband's side, Scott Paterno said.
One of Scott Paterno's lasting memories from the last few months, as his father fought illness, was the picture of his parents sitting at a table at home, surrounded by their children and 17 grandchildren on Dec. 21 as they celebrated his 85th birthday.
"She's got his hand on him and they're sitting there looking around and they've got their smiles on their faces," Scott Paterno said. "Just two of the most happy and contented people looking around the house, looking at their children and their grandchildren and it was like `You know, this is what our life is, this is what we built.'"
ST. PETERSBURG, Fla. ? A landmark Tampa Bay area hotel claims BP has failed to pay an oil-spill claim of more than $5 million.
The Don Cesar Resort Hotel on St. Pete Beach filed a lawsuit against BP Exploration and Production Tuesday in Houston, where the oil company is based.
The suit claims BP reneged on an agreement to pay the hotel $5.2 million for lost business after the Gulf of Mexico oil spill in April 2010. No oil reached the west-central Florida coast, but businesses suffered because of uncertainty over the spill and the false perception that beaches were fouled.
The suit said the hotel accepted BP's written offer of compensation last fall, but the company has so far failed to pay.
BP officials did not return a call seeking comment Wednesday.
Classic arcade fighting game SoulCalibur has hacked and slashed its way onto the iPhone, with all of the vibrant characters and flashy moves you remember, but there are still a few gaps to fill.
But while the returns have produced no revelations about any improper dealings on Romneys' part, they have continued to raise questions about how and why some of his multiple overseas investments were made in the first place, and why there were not more fully reported on Romney's financial disclosure forms.?
But while the returns have produced no revelations about any improper dealings on Romneys' part, they have continued to raise questions about how and why some of his multiple overseas investments were made in the first place, and why there were not more fully reported on Romney's financial disclosure forms.?
STOCKHOLM, Sweden?? A storm from the broiling sun turned the chilly northernmost skies of Earth into an ever-changing and awe-provoking art show of northern lights on Tuesday night.
Even experienced stargazers were stunned by the intensity of the aurora borealis that swept across the night sky in northern Scandinavia after the biggest solar flare in six years.
"It has been absolutely incredible," British astronomer John Mason cried from the deck of the MS Midnatsol, a cruise ship plying the fjord-fringed coast of northern Norway.
"I saw my first aurora 40 years ago, and this is one of the best," Mason told The Associated Press, his voice nearly drowning in the cheers of awe-struck fellow passengers.
U.S. space weather experts from the National Oceanic and Atmospheric Administration said Tuesday evening that so far they had heard of no problems from the storm that triggered the auroras, which made it as far south as Wales, where the weather often doesn't cooperate with good viewing.
It was part of the strongest solar storm in years, but the sun is likely to get even more active in the next few months and years, said physicist Doug Biesecker at the U.S. Space Weather Prediction Center in Boulder, Colo.
"To me this was a wake up call. The sun is reminding us that solar max is approaching," Biesecker said. "A lot worse is in store for us. We hope that you guys are paying attention. I would say we passed with flying colors."
Those who got to see Tuesday night's colorful display marveled at the brilliance.
"It was the biggest northern lights I've seen in the five, six years that I've worked here," said Andreas Hermansson, a tour guide at the Ice Hotel in the Swedish town of Jukkasjarvi, above the Arctic Circle.
He was leading a group of tourists on a bus tour in the area when a green glow that had lingered in the sky for much of the evening virtually exploded into a spectacle of colors around 10:15 p.m. local time
"We stopped the bus. And suddenly it was just this gigantic display of dancing lights and Technicolor," said Michele Cahill, an Irish psychologist who was on the tour. "It was an absolutely awesome display. It went on for over an hour. Literally one would have to lie on the ground to capture it all."
But in temperatures of 30 below zero Fahrenheit (-35 degrees Celsius), that didn't seem like a good idea.
How auroras arise
An aurora appears when a magnetic solar wind slams into the Earth's magnetic field, exciting electrons of oxygen and nitrogen.
More space news from msnbc.com
Space station sees the southern lights
We've been talking a lot about the northern lights lately, but here's a must-see view of the southern lights, as captured by the crew of the International Space Station on Jan. 3.
Solar storm brings fireworks, but few problems
8 years later, Opportunity still roving on Mars
GOP debate spotlights commercial spaceflight
The northern lights are sometimes seen from northern Scotland, but they were also visible Monday night from northeast England and Ireland, where such sightings are a rarity.
"The lights appear as green and red mist. It's been mostly green the past few nights. I don't know if that's just special for Ireland," said Gerard O'Kane, a 41-year-old taxi driver and vice chairman of the Buncrana Camera Club in County Donegal in Ireland's northwest corner.
He and at least two dozen amateur photographers were meeting after dark at a local beach for an all-night stakeout. They've been shooting the horizon from dozens of locations since Friday night.
Scientists have been expecting solar eruptions to become more intense as the sun enters a more active phase of its 11-year cycle, with an expected peak in 2013.
But in recent years the sun appeared quieter than normal, leading scientists to speculate that it was going into an unusually quiet cycle that seems to happen once a century or so.
Effects on Earth
The electromagnetic burst associated with the start of this week's storm occurred at about 11 p.m. ET Sunday, reaching medlum levels. Then, on Monday and Tuesday, the proton radiation from the eruption hit strong levels, the most powerful since October 2003. That mostly affects astronauts and satellites, but NASA said the crew on the International Space Station was not harmed, and Biesecker said only a few minor problems with satellites were reported.
Some airplane flights over the North Pole were rerouted because of expected communication problems from the radiation.
Geomagnetic storms cause awesome sights, but they can also bring trouble. According to the National Oceanic and Atmospheric Administration, problems can include current surges in power lines, and interference in the broadcast of radio, TV and telephone signals. No such problems were reported Tuesday.
A few more days of fireworks
Peter Richardson, a 49-year-old bar manager and part-time poet at the 17th-century Tan Hill Inn in northern England, said the pub ? normally dead on a Monday night in January ? was thronged until the wee hours of the morning with people who came to look at the lights.
"I just thought: 'Oh my God, this is just absolutely amazing,'" he said. "You do get a lot of spectacular skylines out here, but that was just something out of the ordinary. Very different."
Ken Kennedy, director of the Aurora section of the British Astronomical Association, said the northern lights may be visible for a few more days.
The Canadian Space Agency posted a geomagnetic storm warning Tuesday after residents were also treated to a spectacular show in the night sky. John Manuel, a scientist with the Canadian Space Agency, said there was an increased chance of seeing northern lights over northern Canada.
"It's not likely people in the major Canadian cities further south will see a significant aurora tonight," he said Tuesday. "There's always a possibility but the current forecast is for a good show for people who live further north. It should be a particularly good night tonight."
More about solar storms:
AP Science Writer Borenstein reported from Washington. AP writers Louise Nordstrom in Stockholm, Shawn Pogatchnik in Dublin, Raphael Satter in London and Rob Gillies in Toronto contributed to this report.
Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
WASHINGTON (Reuters) ? Federal Reserve Chairman Ben Bernanke said on Wednesday the central bank was ready to offer the economy additional stimulus after it announced interest rates would likely remain near zero until at least late 2014.
The Fed also took the historic step of adopting an explicit inflation target, though Bernanke took pains to stress that officials would be flexible about reining in price growth when unemployment was too high.
The late 2014 timeframe for the first rate hike was considerably later than investors had expected and some 18 months later than the Fed had suggested last year, and the announcement prompted a rally in U.S. government bonds.
Speaking at a news conference after a two-day policy meeting, Bernanke was cautious about recent improvements in the U.S. economy and he left the door open to further Fed bond purchases.
"I don't think we're ready to declare that we've entered a new, stronger phase at this point," Bernanke said. "If the situation continues with inflation below target and unemployment declining at a rate which is very, very slow, then ... the logic of our framework says we should be looking for ways to do more."
In response to the deepest recession in generations, the Fed slashed the overnight federal funds rate to near zero in December 2008. It has also more than tripled the size of its balance sheet to around $2.9 trillion through two separate bond purchase programs.
The policy is credited with preventing an even more devastating downturn, but it has been insufficient to bring unemployment down to levels considered normal during good economic times. Many Fed watchers expected a further round of bond buying, likely focusing on mortgage debt.
RANGE OF VIEWS
Fed officials agreed that a goal of 2 percent inflation would be in keeping with their congressional mandate of price stability. By their favorite measure, core inflation is running at about 1.7 percent.
They declined to announce a target for unemployment, saying the job market was often influenced by forces beyond their control.
In another key shift touted as part of an effort toward greater transparency, the Fed for the first time published policymakers' projections for the appropriate path of the benchmark overnight federal funds rate.
These showed a wide range of views, from the three of 17 policymakers who said they thought rates should rise this year to two who want to hold off on any increase until 2016.
Still, the biggest concentration of estimates - five of 17 - was around 2014. The new, later expiration date for the Fed's zero rate policy pushed stock and gold prices higher, and dragged the dollar lower.
In its announcement, the Fed repeated its view that the economy faced "significant downside risks" - an expression that has become code for the threat Europe's debt crisis poses to the United States.
In economic forecasts accompanying the rate projections, the Fed pointed to somewhat weaker economic growth this year and next, compared with estimates published in November. Meanwhile, the unemployment rate, which hit 8.5 percent in December, was seen only coming down slowly.
Economic conditions "are likely to warrant exceptionally low levels for the federal funds rate at least through late 2014," the central bank said. After every previous policy meeting dating to August, the Fed had said rates were not likely to rise until mid-2013.
Richmond Federal Reserve Bank President Jeffrey Lacker, an inflation hawk who rotated into a voting seat this year, dissented against the policy decision, preferring to omit the late-2014 date from the Fed's post-meeting statement.
INFLATION NOT A WORRY
The central bank appeared more sanguine on inflation, saying prices were likely to run close to or just below their target. The statement dropped a reference that said the Fed was monitoring inflation and inflation expectations.
Aside from the 2014 rate pledge, the Fed's statement hewed closely to its last policy pronouncement in mid-December.
It described the unemployment rate as still elevated and, in a slight shift, acknowledged a slowing in business investment.
"I think what they are seeing is that the rate of growth is not sufficient to bring down the unemployment rate," said Brian Dolan, chief strategist at FOREX.com in Bedminster, New Jersey.
In December, the U.S. jobless rate stood at 8.5 percent, and some 13 million Americans were still actively looking for work but could not find it.
While forecasters expect the U.S. economy grew at a 3 percent annual rate in the last three months of 2011, they look for growth of just around 2 percent this year.
WASHINGTON (Reuters) ? President Barack Obama on Tuesday said he was creating an enforcement unit to crack down on unfair trade practices in China and other countries and would beef up border inspections to block imports of counterfeit goods.
"I will go anywhere in the world to open new markets for American products. And I will not stand by when our competitors don't play by the rules," Obama said in his annual State of the Union speech.
The White House said the new enforcement team would bring together resources and investigators from across the federal government to go after unfair foreign trade practices.
Obama said his administration had already brought trade cases against China "at nearly twice the rate as the last administration ... But we need to do more. It's not right when another country lets our movies, music, and software be pirated. It's not fair when foreign manufacturers have a leg up on ours only because they're heavily subsidized."
Republicans vying to take on Obama in this year's presidential race have slammed his handling of China. Former Massachusetts Governor Mitt Romney has promised a tougher approach, begin with labeling China a currency manipulator.
The U.S. trade deficit with China is expected to hit a new record high of about $300 billion in 2011 when figures are released next month.
The U.S. Trade Representative's office has filed five World Trade Organization cases against China since Obama took office in January 2009, compared to seven during the two terms of former President George W. Bush. China joined the WTO in December 2001.
In addition, the Commerce Department is currently investigating U.S. industry charges of unfair pricing practices by Chinese wind and solar energy equipment manufacturers.
Obama did not mention those cases, but urged Congress to pass tax credits to create more U.S. clean energy jobs.
"I will not cede the wind or solar or battery industry to China or Germany because we refuse to make the same commitment here," he said.
A business group representing U.S. companies that do business in China said it welcomed Obama's push to open China's markets to more U.S. exports.
"Direct negotiation with China is the best first approach to dealing with commercial problems American companies have with China. But we also can use other sound legal tools - such as anti-dumping investigations and WTO cases," said John Frisbie, president of the U.S.-China Business Council.
Another group that represents both labor and domestic manufacturers that compete with China also welcomed the initiative, but urged lawmakers to go further.
Congress should pass "a bipartisan bill to stop China's currency manipulation," said Scott Paul, president of the Alliance for American Manufacturing.
Last month, a top U.S. trade official said China continued to fall short on many of its WTO promises including barriers to its agricultural markets, weak intellectual property rights protection, discriminatory industrial policies and barriers in services.
Obama, in his speech to Congress, promised to increase border inspections to stop counterfeit name-brand goods and other pirated or unsafe products from getting into the United States.
The U.S. Chamber of Commerce complains the worldwide trade in fake goods, many of which come from China, costs the United States hundreds of thousands of good-paying jobs.
Obama said the United States cannot afford to stand by when competitors like China offer cheap government financing to help their businesses win sales overseas.
He also appeared to make a subtle pitch for lawmakers to approve "permanent normal trade relations" with Russia in order to ensure that U.S. companies benefit from the market-opening benefits of Moscow's expected accession to the WTO.
"This Congress should make sure that no foreign company has an advantage over American manufacturing when it comes to accessing finance or new markets like Russia. Our workers are the most productive on Earth, and if the playing field is level, I promise you - America will always win," Obama said.
Contact: Michael Mullaney mullam@rpi.edu 518-276-6161 Rensselaer Polytechnic Institute
Engineers at Rensselaer Polytechnic Institute and Rice University discover how the extreme thinness of graphene enables near-perfect wetting transparency
Troy, N.Y. Graphene is the thinnest material known to science. The nanomaterial is so thin, in fact, water often doesn't even know it's there.
Engineering researchers at Rensselaer Polytechnic Institute and Rice University coated pieces of gold, copper, and silicon with a single layer of graphene, and then placed a drop of water on the coated surfaces. Surprisingly, the layer of graphene proved to have virtually no impact on the manner in which water spreads on the surfaces.
Results of the study were published Sunday in the journal Nature Materials. The findings could help inform a new generation of graphene-based flexible electronic devices. Additionally, the research suggests a new type of heat pipe that uses graphene-coated copper to cool computer chips.
The discovery stemmed from a cross-university collaboration led by Rensselaer Professor Nikhil Koratkar and Rice Professor Pulickel Ajayan.
"We coated several different surfaces with graphene, and then put a drop of water on them to see what would happen. What we saw was a big surprisenothing changed. The graphene was completely transparent to the water," said Koratkar, a faculty member in the Department of Mechanical, Aerospace, and Nuclear Engineering and the Department of Materials Science and Engineering at Rensselaer. "The single layer of graphene was so thin that it did not significantly disrupt the non-bonding van der Waals forces that control the interaction of water with the solid surface. It's an exciting discovery, and is another example of the unique and extraordinary characteristics of graphene."
Results of the study are detailed in the Nature Materials paper "Wetting transparency of graphene." See the paper online at: http://dx.doi.org/10.1038/NMAT3228
Essentially an isolated layer of the graphite found commonly in our pencils or the charcoal we burn on our barbeques, graphene is single layer of carbon atoms arranged like a nanoscale chicken-wire fence. Graphene is known to have excellent mechanical properties. The material is strong and tough and because of its flexibility can evenly coat nearly any surface. Many researchers and technology leaders see graphene as an enabling material that could greatly advance the advent of flexible, paper-thin devices and displays. Used as a coating for such devices, the graphene would certainly come into contact with moisture. Understanding how graphene interacts with moisture was the impetus behind this new study.
The spreading of water on a solid surface is called wetting. Calculating wettability involves placing a drop of water on a surface, and then measuring the angle at which the droplet meets the surface. The droplet will ball up and have a high contact angle on a hydrophobic surface. Inversely, the droplet will spread out and have a low contact angle on a hydrophilic surface.
The contact angle of gold is about 77 degrees. Koratkar and Ajayan found that after coating a gold surface with a single layer of graphene, the contact angle became about 78 degrees. Similarly, the contact angle of silicon rose from roughly 32 degrees to roughly 33 degrees, and copper increased from around 85 degrees to around 86 degrees, after adding a layer of graphene.
These results surprised the researchers. Graphene is impermeable, as the tiny spaces between its linked carbon atoms are too small for water, or a single proton, or anything else to fit through. Because of this, one would expect that water would not act as if it were on gold, silicon, or copper, since the graphene coating prevents the water from directly contacting these surfaces. But the research findings clearly show how the water is able to sense the presence of the underlying surface, and spreads on those surfaces as if the graphene were not present at all.
As the researchers increased the number of layers of graphene, however, it became less transparent to the water and the contact angles jumped significantly. After adding six layers of graphene, the water no longer saw the gold, copper, or silicon and instead behaved as if it was sitting on graphite.
The reason for this perplexing behavior is subtle. Water forms chemical or hydrogen bonds with certain surfaces, while the attraction of water to other surfaces is dictated by non-bonding interactions called van der Waals forces. These non-bonding forces are not unlike a nanoscale version of gravity, Koratkar said. Similar to how gravity dictates the interaction between the Earth and sun, van der Waals forces dictate the interaction between atoms and molecules.
In the case of gold, copper, silicon, and other materials, the van der Waals forces between the surface and water droplet determine the attraction of water to the surface and dictate how water spreads on the solid surface. In general, these forces have a range of at least several nanometers. Because of the long range, these forces are not disrupted by the presence of a single-atom-thick layer of graphene between the surface and the water. In other words, the van der Waals forces are able to "look through" ultra-thin graphene coatings, Koratkar said.
If you continue to add additional layers of graphene, however, the van der Waals forces increasingly "see" the carbon coating on top of the material instead of the underlying surface material. After stacking six layers of graphene, the separation between the graphene and the surface is sufficiently large to ensure that the van der Waals forces can now no longer sense the presence of the underlying surface and instead only see the graphene coating. On surfaces where water forms hydrogen bonds with the surface, the wetting transparency effect described above does not hold because such chemical bonds cannot form through the graphene layer.
Along with conducting physical experiments, the researchers verified their findings with molecular dynamics modeling as well as classical theoretical modeling.
"We found that van der Waals forces are not disrupted by graphene. This effect is an artifact of the extreme thinness of graphenewhich is only about 0.3 nanometers thick," Koratkar said. "Nothing can rival the thinness of graphene. Because of this, graphene is the ideal material for wetting angle transparency."
"Moreover, graphene is strong and flexible, and it does not easily crack or break apart," he said. "Additionally, it is easy to coat a surface with graphene using chemical vapor deposition, and it is relatively uncomplicated to deposit uniform and homogeneous graphene coatings over large areas. Finally, graphene is chemically inert, which means a graphene coating will not oxidize away. No single material system can provide all of the above attributes that graphene is able to offer."
A practical application of this new discovery is to coat copper surfaces used in dehumidifiers. Because of its exposure to water, copper in dehumidifier systems oxidizes, which in turn decreases its ability to transfer heat and makes the entire device less efficient. Coating the copper with graphene prevents oxidation, the researchers said, and the operation of the device is unaffected because graphene does not change the way water interacts with copper. This same concept may be applied to improve the ability of heat pipes to dissipate heat from computer chips, Koratkar said.
"It's an interesting idea. The graphene doesn't cause any significant change to the wettability of copper, and at the same time it passivates the copper surface and prevents it from oxidizing," he said.
###
Along with Koratkar and Ajayan, co-authors of the paper are Yunfeng Shi, assistant professor in the Department of Materials Science and Engineering at Rensselaer; Rensselaer mechanical engineering graduate students Javad Rafiee, Abhay Thomas, and Fazel Yavari; Rensselaer physics graduate student Xi Mi; and Rice mechanical and materials engineering graduate student Hemtej Gullapalli.
This research was supported in part by the Advanced Energy Consortium (AEC); the National Science Foundation (NSF); and the Office of Naval Research (ONR) graphene Multidisciplinary University Research Initiative (MURI).
For more information on Koratkar's graphene research at Rensselaer, visit:
Contact
Michael Mullaney
Rensselaer Polytechnic Institute
Troy, NY
518-276-6161
mullam@rpi.edu
www.rpi.edu/news
Visit the Rensselaer research and discovery blog: http://approach.rpi.edu
Follow us on Twitter: www.twitter.com/RPInews
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AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.
Contact: Michael Mullaney mullam@rpi.edu 518-276-6161 Rensselaer Polytechnic Institute
Engineers at Rensselaer Polytechnic Institute and Rice University discover how the extreme thinness of graphene enables near-perfect wetting transparency
Troy, N.Y. Graphene is the thinnest material known to science. The nanomaterial is so thin, in fact, water often doesn't even know it's there.
Engineering researchers at Rensselaer Polytechnic Institute and Rice University coated pieces of gold, copper, and silicon with a single layer of graphene, and then placed a drop of water on the coated surfaces. Surprisingly, the layer of graphene proved to have virtually no impact on the manner in which water spreads on the surfaces.
Results of the study were published Sunday in the journal Nature Materials. The findings could help inform a new generation of graphene-based flexible electronic devices. Additionally, the research suggests a new type of heat pipe that uses graphene-coated copper to cool computer chips.
The discovery stemmed from a cross-university collaboration led by Rensselaer Professor Nikhil Koratkar and Rice Professor Pulickel Ajayan.
"We coated several different surfaces with graphene, and then put a drop of water on them to see what would happen. What we saw was a big surprisenothing changed. The graphene was completely transparent to the water," said Koratkar, a faculty member in the Department of Mechanical, Aerospace, and Nuclear Engineering and the Department of Materials Science and Engineering at Rensselaer. "The single layer of graphene was so thin that it did not significantly disrupt the non-bonding van der Waals forces that control the interaction of water with the solid surface. It's an exciting discovery, and is another example of the unique and extraordinary characteristics of graphene."
Results of the study are detailed in the Nature Materials paper "Wetting transparency of graphene." See the paper online at: http://dx.doi.org/10.1038/NMAT3228
Essentially an isolated layer of the graphite found commonly in our pencils or the charcoal we burn on our barbeques, graphene is single layer of carbon atoms arranged like a nanoscale chicken-wire fence. Graphene is known to have excellent mechanical properties. The material is strong and tough and because of its flexibility can evenly coat nearly any surface. Many researchers and technology leaders see graphene as an enabling material that could greatly advance the advent of flexible, paper-thin devices and displays. Used as a coating for such devices, the graphene would certainly come into contact with moisture. Understanding how graphene interacts with moisture was the impetus behind this new study.
The spreading of water on a solid surface is called wetting. Calculating wettability involves placing a drop of water on a surface, and then measuring the angle at which the droplet meets the surface. The droplet will ball up and have a high contact angle on a hydrophobic surface. Inversely, the droplet will spread out and have a low contact angle on a hydrophilic surface.
The contact angle of gold is about 77 degrees. Koratkar and Ajayan found that after coating a gold surface with a single layer of graphene, the contact angle became about 78 degrees. Similarly, the contact angle of silicon rose from roughly 32 degrees to roughly 33 degrees, and copper increased from around 85 degrees to around 86 degrees, after adding a layer of graphene.
These results surprised the researchers. Graphene is impermeable, as the tiny spaces between its linked carbon atoms are too small for water, or a single proton, or anything else to fit through. Because of this, one would expect that water would not act as if it were on gold, silicon, or copper, since the graphene coating prevents the water from directly contacting these surfaces. But the research findings clearly show how the water is able to sense the presence of the underlying surface, and spreads on those surfaces as if the graphene were not present at all.
As the researchers increased the number of layers of graphene, however, it became less transparent to the water and the contact angles jumped significantly. After adding six layers of graphene, the water no longer saw the gold, copper, or silicon and instead behaved as if it was sitting on graphite.
The reason for this perplexing behavior is subtle. Water forms chemical or hydrogen bonds with certain surfaces, while the attraction of water to other surfaces is dictated by non-bonding interactions called van der Waals forces. These non-bonding forces are not unlike a nanoscale version of gravity, Koratkar said. Similar to how gravity dictates the interaction between the Earth and sun, van der Waals forces dictate the interaction between atoms and molecules.
In the case of gold, copper, silicon, and other materials, the van der Waals forces between the surface and water droplet determine the attraction of water to the surface and dictate how water spreads on the solid surface. In general, these forces have a range of at least several nanometers. Because of the long range, these forces are not disrupted by the presence of a single-atom-thick layer of graphene between the surface and the water. In other words, the van der Waals forces are able to "look through" ultra-thin graphene coatings, Koratkar said.
If you continue to add additional layers of graphene, however, the van der Waals forces increasingly "see" the carbon coating on top of the material instead of the underlying surface material. After stacking six layers of graphene, the separation between the graphene and the surface is sufficiently large to ensure that the van der Waals forces can now no longer sense the presence of the underlying surface and instead only see the graphene coating. On surfaces where water forms hydrogen bonds with the surface, the wetting transparency effect described above does not hold because such chemical bonds cannot form through the graphene layer.
Along with conducting physical experiments, the researchers verified their findings with molecular dynamics modeling as well as classical theoretical modeling.
"We found that van der Waals forces are not disrupted by graphene. This effect is an artifact of the extreme thinness of graphenewhich is only about 0.3 nanometers thick," Koratkar said. "Nothing can rival the thinness of graphene. Because of this, graphene is the ideal material for wetting angle transparency."
"Moreover, graphene is strong and flexible, and it does not easily crack or break apart," he said. "Additionally, it is easy to coat a surface with graphene using chemical vapor deposition, and it is relatively uncomplicated to deposit uniform and homogeneous graphene coatings over large areas. Finally, graphene is chemically inert, which means a graphene coating will not oxidize away. No single material system can provide all of the above attributes that graphene is able to offer."
A practical application of this new discovery is to coat copper surfaces used in dehumidifiers. Because of its exposure to water, copper in dehumidifier systems oxidizes, which in turn decreases its ability to transfer heat and makes the entire device less efficient. Coating the copper with graphene prevents oxidation, the researchers said, and the operation of the device is unaffected because graphene does not change the way water interacts with copper. This same concept may be applied to improve the ability of heat pipes to dissipate heat from computer chips, Koratkar said.
"It's an interesting idea. The graphene doesn't cause any significant change to the wettability of copper, and at the same time it passivates the copper surface and prevents it from oxidizing," he said.
###
Along with Koratkar and Ajayan, co-authors of the paper are Yunfeng Shi, assistant professor in the Department of Materials Science and Engineering at Rensselaer; Rensselaer mechanical engineering graduate students Javad Rafiee, Abhay Thomas, and Fazel Yavari; Rensselaer physics graduate student Xi Mi; and Rice mechanical and materials engineering graduate student Hemtej Gullapalli.
This research was supported in part by the Advanced Energy Consortium (AEC); the National Science Foundation (NSF); and the Office of Naval Research (ONR) graphene Multidisciplinary University Research Initiative (MURI).
For more information on Koratkar's graphene research at Rensselaer, visit:
Contact
Michael Mullaney
Rensselaer Polytechnic Institute
Troy, NY
518-276-6161
mullam@rpi.edu
www.rpi.edu/news
Visit the Rensselaer research and discovery blog: http://approach.rpi.edu
Follow us on Twitter: www.twitter.com/RPInews
[ | E-mail | Share ]
?
AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.
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Public release date: 23-Jan-2012
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