Looking Towards Curiosity's Canyon Path: a 4 km Sequence of Gully, Debris Deposits, and Fan/Deltas Which are Bordered by a Sloping Bedform-Capped Plain and Crossed by Lake Shorelines

The Curiosity Rover is headed towards layered outcrops that appear to be rich in phyllosilicates and sulphates with the expectation of an eventual ascent up Mt. Sharp. One likely will take the rover up a well-defined canyon. Inspection of CTX and HiRISE imagery and topography (5 m contour intervals) reveal a rich geomorphic sequence that may be encountered during the journey

Parallel Excluded Volume Tempering for Polymer Melts

We have developed a technique to accelerate the acquisition of effectively uncorrelated configurations for off-lattice models of dense polymer melts which makes use of both parallel tempering and large scale Monte Carlo moves. The method is based upon simulating a set of systems in parallel, each of which has a slightly different repulsive core potential, such that a thermodynamic path from full excluded volume to an ideal gas of random walks is generated. While each system is run with standard stochastic dynamics, resulting in an NVT ensemble, we implement the parallel tempering through stochastic swaps between the configurations of adjacent potentials, and the large scale Monte Carlo moves through attempted pivot and translation moves which reach a realistic acceptance probability as the limit of the ideal gas of random walks is approached. Compared to pure stochastic dynamics, this results in an increased efficiency even for a system of chains as short as $N = 60$ monomers, however at this chain length the large scale Monte Carlo moves were ineffective. For even longer chains the speedup becomes substantial, as observed from preliminary data for $N = 200$

Lithographically cut single-walled carbon nanotubes: Controlling length distribution and introducing end-group functionality

Single-walled carbon nanotubes are efficiently cut to precise submicrometer lengths and very narrow length distributions. Chemical functional groups are placed selectively only at the ends without the nanotube walls being modified or damaged. The new methodology includes lithography to place protective photoresist patterns over the nanotubes and reactive ion etching to remove the unprotected nanostructure. This approach enables critical dimensional and chemical control for integrated nanodevice manufacturing based on chemical self-assembly under ambient conditions