[1] We present a global tabulation of black carbon (BC) and primary organic carbon (OC) particles emitted from combustion. We include emissions from fossil fuels, biofuels, open biomass burning, and burning of urban waste. Previous ‘‘bottom-up’’ inventories of black and organic carbon have assigned emission factors on the basis of fuel type and economic sector alone. Because emission rates are highly dependent on combustion practice, we consider combinations of fuel, combustion type, and emission controls and their prevalence on a regional basis. Central estimates of global annual emissions are 8.0 Tg for black carbon and 33.9 Tg for organic carbon. These estimates are lower than previously published estimates by 25–35%. The present inventory is based on 1996 fuel-use data, updating previous estimates that have relied on consumption data from 1984. An offset between decreased emission factors and increased energy use since the base year of the previous inventory prevents the difference between this work and previous inventories from being greater. The contributions of fossil fuel, biofuel, and open burning are estimated as 38%, 20%, and 42%, respectively, for BC, and 7%, 19%, and 74%, respectively, for OC. We present a bottom-up estimate of uncertainties in source strength by combining uncertainties in particulate matter emission factors, emission characterization, and fuel use. The total uncertainties are about a factor of 2, with uncertainty ranges of 4.3–22 Tg/yr for BC and 17–77 Tg/yr for OC. Low-technology combustion contributes greatly to both the emissions and the uncertainties. Advances in emission characterization for small residential, industrial, and mobile sources and topdown analysis combining field measurements and transport modeling with iterative inventory development will be required to reduce the uncertainties further. INDEX TERMS: 0305 Atmospheric Composition and Structure: Aerosols and particles (0345, 4801); 0322 Atmospheric Composition and Structure: Constituent sources and sinks; 0345 Atmospheric Composition and Structure: Pollution—urban and regional (0305); 0360 Atmospheric Composition and Structure: Transmission and scattering of radiation; 0365 Atmospheric Composition and Structure: Troposphere—composition and chemistry; KEYWORDS: emission, black carbon, organic carbon, fossil fuel, biofuel, biomass burning

/pdf/a-technology-based-global-inventory-of-black-and-organic-3mwahkxf6g.pdf

A technology-based global inventory of black and organic carbon emissions from combustion

Preface 1.General Considerations 2.Basic Processes in Atomization 3.Drop Size Distributions of Sprays 4.Atomizers 5.Flow in Atomizers 6.Atomizer Performance 7.External Spray Charcteristics 8.Drop Evaporation 9.Drop Sizing Methods Index

Atomization and Sprays

/pdf/a-comprehensive-review-on-the-applications-of-coal-fly-ash-mt8gcj5phv.pdf

A comprehensive review on the applications of coal fly ash

One of the most important parts of formulating a National Ambient Air Quality Standard is specifying the measurement methods for determining and attaining compliance. The samples taken for compliance are often pushed beyond their original purpose to identify sources, to evaluate the effectiveness of controls, and to determine relationships between pollution levels and public health. A full understanding of available sampling and analysis methods is needed, as well as an analysis of their costs, before acceptable monitoring approached can be specified. This review identifies issues related to measurement methods used to determine compliance with standards, describes current and future measurement methods and their limitations, and determines the extent to which existing technology can meet short-term and long-term needs for measuring compliance.

Measurement Methods to Determine Compliance with Ambient Air Quality Standards for Suspended Particles

a time as one year after leaving the Rehabilitation Unit, and about one quarter were not in competitive jobs but were in sheltered employment. Only just over one quarter were still working in ordinary jobs. Their average wage was £8 I is. 6d. Furthermore if one compares the type of work these patients were able to perform there was a definite decline from their premorbid position. The social class grouping before and after rehabilitation was Class II, i-i, Class III, 9-3, Class IV, 4-6, and Class V, IO-I4. Indeed the authors report that 'even the least handicapped of these patients presented continuous problems . . .' and it is noted that such a programme requires special personnel and a great deal of work. Comparing these results with the extra cost in personnel, time, and effort (which could be directed elsewhere) a Doctor Beeching of the psychiatric services would probably scrap such a rehabilitation service before it even started. But is this the right way of looking at it? The authors point out that such a programme, if applied throughout the country, would affect about 6,ooo patients. If the failure rate were the same as in this experiment, about I,500 would be rescued from a disabled life in a mental hospital and once more returned to an at least partially useful and, one assumes, more satisfying life. Obviously more is involved here than mere economics. We were interested to read that as regards behaviour at the Rehabilitation Centre and during the follow-up year 'There were no outstanding differences' between the schizophrenic and the non-schizophrenic rehabilitees. It appears that the group of schizophrenics had difficulties in social adjustment which were even greater than those of work adjustment. '. . . the men concerned had greater difficulty in living outside hospital, than in working outside hospital. If, however, adequate arrangements are made to cater for these various needs, there seems to be every reason to expect that a small selected group of long stay schizophrenic patients can be successfully resettled in work.' The experiment and the report show the high standards we have come so confidently to expect from Dr. Wing and his colleagues, and the publication will be read with interest, not only by psychiatrists, but by all those concemed with rehabilitation problems of chronically disabled patients. J. HOENIG

https://oem.bmj.com/content/oemed/23/2/161.2.full.pdf

The Mechanics of Aerosols

A study of the physical and morphological properties of four fractions of size-classified coal fly ash is reported. Volume medium diameters of the four size fractions are 2.2, 3.2, 6.3, and 20 millimicron, respectively. The size distributions of the four fractions are compared to isokinetically collected samples. Density variations and results of three standard particle sizing techniques are discussed in terms of particle size and morphological properties. Eleven morphological particle types are quantified by light microscopy. Relative abundances of the 11 morphological particle types within each size cut appear to be particle size dependent. The finest fraction is composed of 87% nonopaque solid spheres and 7.9% cenospheres in contrast to the coarsest fraction composed of 26% nonopaque solid spheres and 41% cenospheres. The density variation with particle size is explained in terms of the relative abundances of predominant particle types. On the basis of morphological appearance, a coal fly ash morphogenesis scheme is developed. /Author/

Physical and morphological studies of size-classified coal fly ash

Large particle collection characteristics of ambient aerosol samplers

A technical basis has been developed which justifies using two nondimensional parameters: the ratio of the cutpoint particle diameter to the cyclone diameter, (D 0.5 /D c ) and the flow Reynolds numbers, Ref. An improved method has also been developed for the design of single-inlet aerosol sampling cyclones using these parameters in a semiempirical functional relation. This allows predictions to be made of aerodynamic equivalent particle (AED) cutpoint diameter for a Stairmand cyclone which has had an alteration to its outlet tube diameter. The correlation coefficient for the functional relationship is r 2 >0.99. Using a particular cyclone, a designer can hold the airflow rate constant and then predict how the particle cutpoint will change as the outlet tube diameter is changed

Performance modeling of single-inlet aerosol sampling cyclones

Particle collection characteristics of a single-stage dichotomous sampler

A wetted wall bioaerosol sampling cyclone with an aerosol sampling flow rate of 1250 L/min and a continuous liquid outflow rate of about 1 mL/min was developed by upgrading an existing system. The aerosol-to-hydrosol collection efficiency curve for the upgraded device was shown to have a cutpoint of 1.2 μ m aerodynamic diameter (AD) and an average collection efficiency of 90% over the size range of 2 to 10.2 μ m AD. Tests with near-monodisperse cells and clusters of Bacillus atrophaeus (aka BG) spores showed an average aerosol-to-hydrosol collection efficiency of 98% over the size range from 1.7 to 9.8 μ m AD. Pressure drop across the cyclone, which is also the ideal specific power, was 5.5 kPa (22 inches H2O). Stokes scaling was used to design geometrically similar cyclones with nominal air sampling flow rates of 100 and 300 L/min. Extensive tests were performed with the 100 L/min unit and check tests with the 300 L/min. Results with the scaled units showed similar, although somewhat lower collection eff...

https://www.tandfonline.com/doi/pdf/10.1080/02786820903555552

Andrew R. McFarland

Papers

Physical and morphological studies of size-classified coal fly ash

Large particle collection characteristics of ambient aerosol samplers

Performance modeling of single-inlet aerosol sampling cyclones

Particle collection characteristics of a single-stage dichotomous sampler

Wetted Wall Cyclones for Bioaerosol Sampling