In an interesting paper in a recent issue (vol 17, issue 14) of the journal, Enstrom examined the association between fine particulate matter (PM) pollution and mortality in a cohort of elderly Californians. The analyses used proportional hazards regression and after adjusting for age, sex, cigarette smoking, and other potential confounders, Enstrom concluded, “These epidemiologic results do no...

The effect of fine particles on turbulence damping and reduction of flow friction coefficient in ribleted pipes, have been investigated experimentally. Tests have been conducted in a ribleted pipe with hydraulic diameter of 18.6 mm, and 20 stream wise riblets of 1.8 mm depth, along the pipe. Flows of water tap with Reynolds number from 5000 to 30000 were compared with flows containing silt-clay...

the removal of fine particles less than 2.5 μm in diameter generated from industrial plantsrepresents a serious challenge in air pollution abatement. these particles can penetrate deeply into the lungs and are difficult to remove by cyclones, electrostatic precipitators, and other conventional separation devices. in this paper, the influence of acoustic waves on removing aerosol particles from ...