We have performed the first “high-pressure” XPS study on the palladium, hydrogen and olefin (trans-2-pentene) system in order to gain a better insight into the hydrogenation reaction. We report here data collected using a Pd(111) single crystal and a polycrystalline foil. Hydrogenation was observed on polycrystalline foil (RT and 373 K), but not on Pd(111) single crystal, revealed by on-line ma...

We reported a simple and practical strategy that enables us to control the nucleation density and growth kinetics for graphene grown on the top-surface of metal substrate through gettering the carbon source on the backside of the flat Cu foil, during chemical vapor deposition (CVD). Hitherto, for CVD graphene grown on a flat Cu foil, merely topsurface-based growth mechanism has been emphasized,...

We show experimentally that flapping foil kinematics consisting of a power downstroke and a feathering upstroke together with a properly timed in-line motion, similar to those employed in forelimb propulsion of sea turtles, can produce high thrust and be hydrodynamically as efficient as symmetrically flapping foils. The crucial parameter for such asymmetrically flapping foils is a properly size...

Finnegan, the Massachusetts Institute of Technology Biomimetic Flapping Foil Autonomous Underwater Vehicle (BFFAUV), was developed to explore the use of two degree of freedom oscillating foils as the sole means of propulsion and maneuvering for an underwater vehicle. Two pairs of foils with 0.4m span x 0.1m chord are used, with one pair forward and one pair aft of the center of gravity, with th...

Calcium silicate hydrate (CSH) is the major volume phase in the matrix of Portland cement concrete. Total x-ray scattering measurements with synchrotron x rays on synthetic CSH(I) shows nanocrystalline ordering with a particle diameter of 3.5(5) nm, similar to a size-broadened 1.1 nm tobermorite crystal structure. The CSH component in hydrated tricalcium silicate is found to be similar to CSH(I...

A new physical mechanism or mode of plastic deformation in nanocrystalline metals and ceramics is suggested and theoretically described. The mode represents the cooperative grain boundary (GB) sliding and stress-driven GB migration process. It is theoretically revealed that the new deformation mode is more energetically favorable than "pure" GB sliding and enhances the ductility of nanocrystall...

The International Moth is an ultra-lightweight foiling dinghy class. Foil deflections and dynamic sailor-induced motions are identified as two key areas relating to foiling moth performance that are currently ignored in Velocity Prediction Programs (VPP). The impact of foil deflections is assessed by measuring the tip deflection and twist deformation of a T-foil from an International Moth. The ...

The hydrodynamics and energetics of bioinspired oscillating mechanisms have received significant attentions by engineers and biologists to develop the underwater and air vehicles. Undulating and pure heaving (or plunging) motions are two significant mechanisms which are utilized in nature to provide propulsive, maneuvering, and stabilization forces. This study aims to elucidate and compare the ...

The magnetic compass orientation of birds is light dependent. The respective directional information, originating in radical pair processes, is mediated by the right eye. These findings suggest possible interactions between magnetoreception and vision, in particular with the perception of contours, because the right eye has been found to be dominant in discrimination tasks requiring object visi...