Aerosol, definition

Methane, See also Liquefied natural gas Natural gas, 41, 47, 258, 291, 484 physical properties, 295 vapour pressure, 294 Micro-organisms, 1, 138 Mineral acids, 27, 28 Mineral oils, 15, 159, 166 Mists, See also Aerosols definition, 14 origin, 51... 

Aerosilogel, definition, 7 Aerosol, definition, 7 After-treated synthetic amorphous silicas applications, 490 example, 489/... 

Classically, aerosols are particles or droplets that range from about 0.15 to 5 p.m ia size and are suspended or dispersed ia a gaseous medium such as air. However, the term aerosol, as used ia this discussion, identifies a large number of products which are pressure-dispensed as a Hquid or semisohd stream, a mist, a fairly dry to wet spray, a powder, or even a foam. This definition of aerosol focuses on the container and the method of dispensiag, rather than on the form of the product. 

Aerosol technology may be defined as involving the development, preparation, manufacture, and testing of products that depend on the power of a hquefied or compressed gas to expel the contents from a container. This definition can be extended to iaclude the physical, chemical, and toxicological properties of both the finished aerosol system and the propellants. 

Standardized techniques atomic absorption (AAA) and photometric (FMA) of the analysis and designed by us a technique X-Ray fluorescence of the analysis (XRF) for metals definition in air of cities and the working areas of plants to production of non-ferrous metals are applied. The samples of aerosols were collected on cellulose (AFA-HA) and perchlorovinyl (AFA-VP and FPP) filters (Russia). The techniques AAA and FMA include a stage of an acid-temperature ashing of a loaded filter or selective extraction of defined elements from filter by approaching dissolvent. At XRF loaded filters were specimens. 

For exposure of reasons of observable discrepancy of results of the analysis simulated experiment with application synthetic reference samples of aerosols [1]. The models have demonstrated absence of significant systematic errors in results XRF. While results AAA and FMA depend on sort of chemical combination of an elements, method of an ashing of a material and mass of silicic acid remaining after an ashing of samples. The investigations performed have shown that silicic acid adsorbs up to 40 % (rel.) ions of metals. The coefficient of a variation V, describing effect of the indicated factors on results of the analysis, varies %) for Mn and Fe from 5 up to 20, for Cu - from 10 up to 40, for Pb - from 10 up to 70, for Co the ambassador of a dry ashing of samples - exceeds 50. At definition Cr by a method AAA the value V reaches 70 %, if element presences an atmosphere in the form of Cr O. At photometric definition Cr (VI) the value V is equal 40%, when the element is present at aerosols in the form of chromates of heavy metals. 

Equation (1) points to a number of important particle properties. Clearly the particle diameter, by any definition, plays a role in the behavior of the particle. Two other particle properties, density and shape, are of significance. The shape becomes important if particles deviate significantly from sphericity. The majority of pharmaceutical aerosol particles exhibit a high level of rotational symmetry and consequently do not deviate substantially from spherical behavior. The notable exception is that of elongated particles, fibers, or needles, which exhibit shape factors, kp, substantially greater than 1. Density will frequently deviate from unity and must be considered in comparing aerodynamic and equivalent volume diameters. 

Although carbon has long been recognized as an important constituent of ambient aerosols, the analysis of carbon in its many molecular forms has presented formidable obstacles. An approach taken by many investigators (1-12) has been to separate aerosol carbon into organic, elemental, and carbonate classes. However, at the present time only carbonate carbon has an unequivocal analytical definition. Speciation between organic and elemental car-... 

If the blackness of the particulate matter collected on a filter is due to the graphitic carbon content of the sample, then the Km unit should convert to ambient elemental carbon concentrations. The form of that translation is apparent from the definition of the Km unit. Elemental carbon concentration measurements made by laboratory reflactometers calibrated against heated butane soot standards show that elemental carbon concentrations are linearly related to the log of the reflectance ratio R /R. Aerosol loadings stated in Km units should be directly proportional to elemental carbon concentrations sampled. 

Aerosols are defined as relatively stable suspensions of solid or liquid particles in a gas. Thus aerosols differ from particles in that an aerosol includes both the particles and the gas in which they are suspended. However, while this is the rigorous definition of aerosols, one should note that the term is often used in the atmospheric chemistry literature to denote just the particles. 

Our experiments indicate that cnltnred subconfluent autologons keratinocytes, when applied via aerosol in dermal substitute-grafted full-thickness wonnds, have the ability to snrvive and proliferate in vivo thus contributing to definitive wonnd... 

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