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Associated Press
President Barack Obama and Joint Center for Energy Storage Research Director Dr. George Crabtree walk past a hybrid Chevy Volt vehicle used for testing during the president's tour of the Argonne National Laboratory in Argonne, Ill., Friday, March 15, 2013. Argonne is the first US science and engineering research national laboratory, and it remains on of the nation’s largest. (AP Photo/Pablo Martinez Monsivais)

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