Multiscale simulation of loading and electrical resistance in silicon nanoindentation

Nanoindentation experiments are an excellent probe of micromechanical properties, but their interpretation is complicated by their multiscale nature. We report simulations of silicon nanoindentation, based on an extended version of the local quasicontinuum model, capable of handling complex Bravais crystals. Our simulations reproduce the experimental load vs displacement curves and provide microscopic information such as the distribution of transformed metallic phases of silicon underneath the indenter. This information is linked to the macroscopic electrical resistance, giving a satisfactory explanation of experimental results.

The Changing Risks of Drowning for Adolescents in the U.S. and Effective Control Strategies.

Drowning is the second leading cause of unintentional injury death among adolescents. The authors describe the epidemiology of adolescent drowning and near-drowning; review the literature with emphasis on what is known about risk factors, treatment, and prevention; and identify the gaps in our knowledge on the circumstances surrounding submersion injuries in this age group.