Effect of Extrinsic Disorder on the Magnetoresistance Response of Gated Single-Layer Graphene Devices.

Analogous to the case of classical metal oxide semiconductor field-effect transistors, transport properties of graphene-based devices are determined by scattering from adventitious charged impurities that are invariably present. The presence of charged impurities renders experimental graphene samples "extrinsic" in that their electrical performances also depend on the environment in which graphene operates. While the role of such an extrinsic disorder component has been studied for conventional charge transport in graphene, its impact on the magnetotransport remains unexplored.

Ultrastructures and Mechanics of Annealed Major Ampullate Silk.

The semicrystalline protein structure and impressive mechanical properties of major ampullate (MA) spider silk make it a promising natural alternative to polyacrylonitrile (PAN) fibers for carbon fiber manufacture. However, when annealed using a similar procedure to carbon fiber production, the tensile strength and Young's modulus of MA silk decrease. Despite this, MA silk fibers annealed at 600 °C remain stronger and tougher than similarly annealed PAN but have a lower Young's modulus.