Industrial exoskeletons: Need for intervention effectiveness research.

Exoskeleton devices are being introduced across several industry sectors to augment, amplify, or reinforce the performance of a worker's existing body components-primarily the lower back and the upper extremity. Industrial exoskeletons may play a role in reducing work-related musculoskeletal disorders arising from lifting and handling heavy materials or from supporting heavy tools in overhead work. However, wearing an exoskeleton may pose a number of risks that are currently not well-studied.

Ion solvation in a water-urea mixture.

We employ molecular dynamics simulations and the reference interaction site model (RISM) integral equation theory to study the solvation structure and solvation thermodynamics of the transfer process from water to a water-urea mixture. Simple positive and negative ions together with uncharged species of the same size are used as crude models for the hydrophilic and hydrophobic groups of a protein. We find that urea preferentially solvates positively charged species.

A comparative study of unrelaxed surfaces on quartz and kaolinite, using the periodic density functional theory.

To investigate surface properties of fractured silica particles, which are commonly connected to the etiology of silica toxicity, models of low-index unrelaxed surfaces of quartz and kaolinite were constructed and analyzed using the periodic density functional theory calculations. The models were used to investigate surface sites that emerge in the processes of heterolytic and homolytic cleavage of quartz. It is found that the quartz surface is stabilized by two types of interactions.

Reconstruction of pristine and hydrolyzed quartz surfaces.

Reconstruction of the most common pristine and hydrolyzed surfaces of quartz was investigated with periodic density functional theory calculations. Surface energies of reconstructed pristine faces, pertinent to quartz growth morphologies in melts, are found to range from 0.071 eV/A2 for the (101) surface to 0.