Variability in muscle activity and wrist motion measurements among workers performing non-cyclic work.

Appropriate sampling strategies for estimation of exposure to physical risk factors require knowledge of exposure variability over time. Limited information is available about the variability of exposure to physical risk factors for upper extremity musculoskeletal disorders, especially during non-cyclic work activities. We investigated the magnitude and relative contributions of several sources of variance to the total exposure variance among office, custodial, or maintenance workers (N = 5 per group).

Enhanced permanganate in situ chemical oxidation through MnO2 particle stabilization: evaluation in 1-D transport systems.

In situ chemical oxidation using permanganate is an increasingly employed approach to organic contaminant remediation at hazardous waste sites. Manganese dioxide (MnO2) particles form as a by-product of the reaction of permanganate with contaminants and naturally-reduced subsurface materials. These particles are of interest because they have the potential to deposit in the subsurface and impact the flow regime in/around permanganate injection, including the well screen, filter pack, and the surrounding subsurface formation.