Effective density of inhaled environmental and engineered nanoparticles and its impact on the lung deposition and dosimetry.

Background: Airborne environmental and engineered nanoparticles (NPs) are inhaled and deposited in the respiratory system. The inhaled dose of such NPs and their deposition location in the lung determines their impact on health. When calculating NP deposition using particle inhalation models, a common approach is to use the bulk material density, ρ, rather than the effective density, ρ.

Toward Elimination of Soot Emissions from Jet Fuel Combustion.

Soot from jet fuel combustion in aircraft engines contributes to global warming through the formation of contrail cirrus clouds that make up to 56% of the total radiative forcing from aviation. Here, the elimination of such emissions is explored through N injection (containing 0-25 vol % O) at the exhaust of enclosed spray combustion of jet fuel that nicely emulates aircraft soot emissions. It is shown that injecting N containing 5 vol % of O enhances the formation of polyaromatic hydrocarbons (PAHs) that adsorb on the surface of soot.