Showing papers by "JoAnn S. Lighty published in 2003"
TL;DR: Diluted exhaust from selected military aircraft ground-support equipment (AGE) was analyzed for particulate mass, elemental carbon (EC) and organic carbon (OC), SO4 2−, and size distributions, and it was shown that the distribution of SO2 2− mass mirrored the Distribution of particle mass.
Abstract: Diluted exhaust from selected military aircraft ground-support equipment (AGE) was analyzed for particulate mass, elemental carbon (EC) and organic carbon (OC), SO4 2−, and size distributions. The experiments occurred at idle and load conditions and utilized a chassis dynamometer. The selected AGE vehicles operated on gasoline, diesel, and JP-8. These military vehicles exhibited concentrations, size distributions, and emission factors in the same range as those reported for nonmilitary vehicles. The diesel and JP-8 emission rates for PM ranged from 0.092 to 1.1 g/kg fuel. The EC contributed less and the OC contributed more to the particulate mass than reported in recent studies of vehicle emissions. Overall, the particle size distribution varied significantly with engine condition, with the number of accumulation mode particles and the count median diameter (CMD) increasing as engine load increased. The SO4 2− analyses showed that the distribution of SO4 2− mass mirrored the distribution of parti...
21 citations
TL;DR: In this paper, a selection of Air Force ground support vehicles was subjected to gravimetric, carbon, and size distribution analyses in September 1999 and the results showed that the relative number count of accumulation mode particles increased with respect to nucleation mode particles as engine rpm increased.
Abstract: Diluted exhaust from a selection of Air Force ground support vehicles was subjected to gravimetric, carbon, and size distribution analyses in September 1999. The vehicles operated on diesel and JP-8 fuels. In most cases, the engines involved were similar to civilian counterparts. The tests involved "low" and "high" idle settings but no external loads were imposed. Particle size distribution data, obtained over the 10 to 352 nanometer diameter range using an SMPS instrument, showed that the relative number count of accumulation mode particles increased with respect to nucleation mode particles as the engine rpm increased. The SMPS distributions often explained the main variations in the integrated PM 2.5 gravimetric mass data. Particulate mass derived from the SMPS data and from cascade impactor measurements were well correlated (regression slope 1.02). Empirically determined "elemental" carbon (EC) and "organic" carbon (OC) were the main constituents of the PM 2.5 gravimetric mass (regression slope 0.89)....
18 citations
01 Oct 2003
TL;DR: In this article, the authors developed and validated innovative techniques for characterizing the amount and composition of PM10, PM2.5 and smaller particles for four major classes of DoD emission sources: aircraft ground support vehicles, rocket motors, aircraft, and sandblasting operations.
Abstract: : This study developed and validated innovative techniques for characterizing the amount and composition of PM10, PM2.5, and smaller particles for four major classes of DoD emission sources: aircraft ground support vehicles, rocket motors, aircraft, and sandblasting operations. The techniques include the coupling of dilution samplers with advanced measurement techniques for composition and size that provide detailed analyses sufficient to complete a material balance. The size-classified analyses include measurement made with the cascade impactor and aerosol time-of-flight mass spectrometer (ATOFMS). A photoelectric aerosol sensor (PAS) was being evaluated for use in rapidly evaluating field emissions of particle-bound polycyclic aromatic hydrocarbons (PAH). In addition, a photoacoustic spectrometer was investigated for use in measuring soot particle concentrations. The objective was to calibrate and enhance these instruments for DOD use. To this end, the devices are being demonstrated at DoD facilities, and the methodologies developed will be transferred to personnel responsible for monitoring emissions at DoD facilities
5 citations