Atmosphere respirable fraction

Experimental studies of oil shale combustion fly ash aerosol under simulated day-time and night-time atmospheric-like conditions were performed at NICPB in a 190m outdoor Teflon film chamber. Continuous monitoring of particle size distributions is performed with various optical and electrical devices. The respiration fraction of particles, which contributes most to the health effects of the aerosols, is studied quantitatively. 

Cahill TA, Ashbaugh LL, Baeone JB, Eldeed RA, Eeeney PJ, Elogghini RG, Goodaet Ch, Shaddoan DJ and Wolle FW (1977) Analysis of respirable fractions in atmospheric particulates via sequentied filtration. J Air Pollut Control Assoc 27 675-678. 

In the above case, the source term means how much airborne Pu02 particulates are released to the atmosphere due to the drop of a container, what is the respirable fraction of the airborne Pu02 particulates. 

Improved control devices now frequently installed on conventional coal-utility boilers drastically affect the quantity, chemical composition, and physical characteristics of fine-particles emitted to the atmosphere from these sources. We recently sampled fly-ash aerosols upstream and downstream from a modern lime-slurry, spray-tower system installed on a 430-Mw(e) coal utility boiler. Particulate samples were collected in situ on membrane filters and in University of Washington MKIII and MKV cascade impactors. The MKV impactor, operated at reduced pressure and with a cyclone preseparator, provided 13 discrete particle-size fractions with median diameters ranging from 0,07 to 20 pm with up to 6 of the fractions in the highly respirable submicron particle range. The concentrations of up to 35 elements and estimates of the size distributions of particles in each of the fly-ash fractions were determined by instrumental neutron activation analysis and by electron microscopy, respectively. Mechanisms of fine-particle formation and chemical enrichment in the flue-gas desulfurization system are discussed. 

Similar terms can be derived for other flux components based on knowledge of the isotopic composition of the source material (e.g., atmospheric CO2, ocean-surface inorganic carbon, soil organic carbon) and knowledge of the associated, process-based, isotopic fractionation (e.g., sp for photosynthesis, cr for respiration). Note also that terms such as 5a -b Sao in Equation (14) are also approximations of A. ... 

Figure 4 The global disequilibrium effect. value of CO2 currently fixed into plants (associated with photosynthetic discrimination, is lower than that of older CO2 respired back to the atmospheric CO2 (no fractionation is assumed). This is due to the rapid decrease in atmospheric associated with fossil fuel emissions, on the one hand, and to the slow turnover of carbon in the biosphere, on the other hand. A similar disequilibrium occurs in the ocean where the atmospheric trend influences the values of newly formed Die, while the ocean mean DIG pool lags behind this equilibrium values due to slow mmover rates (not shown). The atmospheric trend shown is based on the best fit line to the data of Francey et al. (1999) the land organic matter trend is obtained by appl3ung global mean = 18%o, and moving it back in time by 27 yr, the first order estimate of global mean soil carbon turnover time. The resulting 0.6%o disequilibrium for the 1990s is within the range of current estimates for both land and ocean.

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