The size at which nonplanar isomers of neutral, pristine gold nanoclusters become energetically favored over planar ones is still debated amongst theoreticians and experimentalists. Spectroscopy confirms planarity is preferred at sizes up to Au7, however, starting with Au8, the uncertainty remains for larger nanoclusters. Au8 computational studies have had different outcomes: the planar D4h "cl...

Friction stir welding, a solid state innovative joining technique, is widely being used to join aluminium alloys for aerospace, marine automotive and many other applications of commercial importance. FSW trials were carried out using a vertical machining centre (VMC) on AA6061 alloy. The main objective of the present work was to evaluate the weld processing parameter of friction stir weld (FSW)...

In a spatial regression context, scientists are often interested in a physical interpretation of components of the parametric covariance function. For example, spatial covariance parameter estimates in ecological settings have been interpreted to describe spatial heterogeneity or “patchiness” in a landscape that cannot be explained by measured covariates. In this article, we investigate the inf...

Vivek A. Sujan Steven Dubowsky Massachusetts Institute of Technology Department of Mechanical Engineering Cambridge, Massachusetts 02139 Abstract. The basic technology for a robotic system is developed to automate the packing of polycrystalline silicon nuggets into fragile fused silica crucible in Czochralski (melt pulling) semiconductor wafer production. The highly irregular shapes of the nugg...