A Shell-owned ethylene cracker plant on Pulau Bukom, Singapore. Several U.S. states are competing for a similar plant the company plans to build in northern Appalachia. Courtesy of Shell Chemicals hide caption

itoggle caption Courtesy of Shell Chemicals

The town of Nitro has its beginnings in 1917, when the U.S. government created it as a place to locate a munitions plant. Jeff Brady/NPR hide caption

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A woman pays her respects at a statue of Joe Paterno outside Beaver Stadium on the Penn State University campus in State College, Pa., after learning of his death on Sunday. Gene J. Puskar/AP hide caption

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The Syncrude tar sands mine in Alberta, Canada. Alberta's tar sands would supply the oil for the prospective Keystone XL pipeline. Todd Korol/Reuters/Landov hide caption

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The Syncrude tar sands mine north of Fort McMurray, Alberta, is seen in November. Alberta's tar sands would supply the oil for the prospective Keystone XL pipeline. Todd Korol/Reuters/Landov hide caption

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Rick Santorum receives a call at his campaign headquarters during his Senate re-election bid in 2006. The former senator was attempting to keep his Pennsylvania Senate seat, which he later lost to Democrat Bob Casey Jr. Jeff Swensen/Getty Images hide caption

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Distillation towers, tanks and other equipment at Sunoco's sprawling refinery on the banks of the Schuylkill River on Aug. 3, 2009. Sunoco is selling off two refineries and, in September, announced it would get out of the refining business. Richard Richtmyer/AP hide caption

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House Minority Leader Rep. Nancy Pelosi talks to reporters in the U.S. Capitol on Friday. Pelosi was critical of Speaker John Boehner and the GOP leadership for recessing the House without passing extensions of the payroll tax cut and unemployment benefits, both set to expire at the end of the year. Chip Somodevilla/Getty Images hide caption

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Former U.S. Sen. Rick Santorum greets voters this summer in Iowa. The Republican presidential hopeful has spent most of his professional life in politics. Chip Somodevilla/Getty Images hide caption

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A woman casts her ballot during early voting in Toledo, Ohio. Members of the silent generation are more likely to vote for Republicans than for Democrats, according to a recent study by the Pew Research Center. J.D. Pooley/Getty Images hide caption

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Union posters can be found all over the Occupy Philadelphia protest site near City Hall. Protesters and local union leaders meet regularly to discuss tactics and how to involve labor.

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Chapman Corp. is expanding to take advantage of extra business it expects to get in coming decades because of increasing production in the Marcellus Shale play.

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