Coarse particulates

Fig. 6. Size distribution of an urban aerosol showing the three modes containing much of the aerosol mass. The fine mode contains particles produced by condensation of low volatility gases. The mid-range, or accumulation mode, results from coagulation of smaller aerosols and condensation of gases on preexisting particles. Coarse particulates, the largest aerosols, are usually generated mechanically.

The main objective of air quality guidelines and standards is the protection of human health. Since fme particulates (PM,) are more likely to cause adverse health effects than coarse particulates, guidelines and standards referring to fine particulate concentrations are preferred to those referring to TSP, which includes coarse particulate concentrations. Scientific studies provide ample evidence of the relationship between exposure to short-term and long-term ambient particulate concentrations and human mortality and morbidity effects. However, the dose-response mechanism is not yet fully understood. Furthermore, according to the WHO, there is no safe threshold level below which health damage does not occur. 

Fine particulates Coarse particulates Sulfur oxides Reduced sulfur gases Volatile organic compounds Nitrogen oxides... 

Calcining (lime kiln) Lime mud Lime Fine and coarse particulates Air... 

Recovery furnaces and boilers Air Fine and coarse particulates, nitrogen oxides, SO2... 

Sources, Composition, and Health Effects of Coarse Particulate Matter... 

Concrete is commonly thought of simply as a mixture of a cement with some coarsely particulate material or aggregate, but it is more than that components of the paste bind chemically to the surface of the aggregate, giving added strength to the whole. The nature of this bonding seems to be similar to that occurring within the paste itself. 

Because of the labor-intensive nature of annular denuder sampling, alternative techniques deserve further scrutiny. The DDM, relying on Teflon-nylon filter packs (or nylon filters alone) and an anodized aluminum annular denuder ahead of one of a pair of modified dichotomous samplers (46), merits evaluation for the influence of potential interferents (e.g., HONO). The DDM with NaCl-coated denuders would probably be nearly free of interference from HONO, but this conclusion requires evaluation. Because coarse particulate N03 must be excluded to achieve improved accuracy for HN03 and fine particulate N03, supplementary samplers are needed to obtain improved estimates of total as well as coarse particulate... 

Almeida SM, Pio CA, Freitas MC, Reis MA, Trancoso MA (2005) Source apportionment of fine and coarse particulate matter in a sub-urban area at the Western European Coast. Atmos Environ 39 3127-3138... 

Yoon, Y.H. and Brimblecomhe, P. (2001) The distribution of soiling by coarse particulate matter in the museum environment. Indoor Air, 11, 232 10. 

Ames, M., Gullu, G. and Olmez, I. (1998) Atmospheric mercury in the vapor phase, and in fine and coarse particulate matter at Perch River, New York. Atmos. Environ., 32,865-872. 

In the basic system the mobile phase is contained in a reservoir. This reservoir may or may not be pressurized (to approximately 3-6 psi). The mobile phase should be prefiltered before being placed into this reservoir, yet a filter is usually placed in the reservoir to be a sinker to hold the inlet at the bottom of the reservoir and to remove any accidental contamination of coarse particulate matter (20-30 /um) before it reaches the solvent delivery system (the pump). Since this is a low-pressure line, Teflon tubing (1 in. OD or larger) is usually used to ensure that sufficient volume of mobile phase reaches the solvent delivery system. Addition considerations for mobile phase preparation are given in Chapter 6. 

The relationship between alkalinity and FSS concentration and Andean source waters was expected because > 80% of suspended materials and dissolved solids in transport in the Amazon are derived from Andean regions (Gibbs 1972, Stallard 1980, Meade et al. 1985). Although the Andes are also the dominant source of CSS, its seasonal cycle is tied more to the river surface slope than the percent Andean water. In fact, the seasonal pattern of river slope has a nearly identical shape to CSS concentration (Devol et al. 1995). Deposition occurs during periods of low slope (low turbulence), whereas resuspension predominates during high slope (Meade et al. 1985). This changing balance would also explain the relationships between coarse particulate... 

As the printed circuit boards used in electrical equipment for automobiles and airplanes are exposed to severe environments involving coarse particulates, rapid temperature variations, high temperature and high humidity, for example, there is the possibility of mechanical damage or the occurrence of electrical problems in board components. An environmentally resistant conformal coating is used to protect board surfaces. 

Coarse particulate boron carbide is produced by reacting boron/oxygen compounds with carbon. Its worldwide production in 1995 was 600 t/a... 

The lamp black process produces particularly coarse particulate carbon black with a high density ( heavy black ). Due to the broad particle size distribution of 60 to 200 nm, it has not been possible to replace lamp black with furnace black in some applications. 

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