The large-scale production of high-quality graphene layers is one of the main challenges to be overcome for successful application of this material. Epitaxial growth on ruthenium substrate produces homogeneous domains of single- and double-layer graphene on the scale of several tens of micrometres. The electronic properties of the second layer show great potential for applications.
Democrat Barack Obama's appeal to  centrist voters has further opened the door to Republican claims his message of change only applies to the positions he has taken in the past.
AP - Iran indicated Saturday that it has no plans to meet a key Western demand that it stop enriching uranium, a day after Tehran sent the European Union a response to an international offer of incentives for halting enrichment.
AP - The call girl involved in a scandal that brought down New York's former governor has dropped a lawsuit claiming "Girls Gone Wild" founder Joe Francis exploited her image and name on the Internet.
