Dust and smoke

Ranz and Wong (8S-1 OS) have made a detailed investigation of the impaction of dust and smoke particles on surface and body collectors, and have developed a mathematical statement of the problem. They include an outline of the history of jet impaction work. 

A particular, and unusual, atmospheric application of such data involves the formation of noctilucent clouds (NLC s) in the vicinity of the mesopause (at 82 km, in the summer hemisphere, where temperatures can fall as low as 130 K, and ice can exist even at the miniscule ambient water vapor concentrations found there). The presence of laige water-aggregated hydronium ions led to the suggestion [e.g., 63-65] that these provide condensation sites for ice particles. Detailed simulation studies bore out the likely relationship between positive ion nucleation and the behavior of some NLC s [66], notwithstanding a strong possibility that meteoritic dust and smoke also had a dominant role [67], ITie contribution to NLC formation of hydronium-ion/electron... 

Concern regarding the exposure of pregnant women to tobacco dust and smoke has existed since at least the middle of the nineteenth century. During the subsequent years many studies have reported the association of cigarette smoking with numerous problems of pregnancy. One of the most important observations in experimental... 

An assessment of the potential exposure to dust and smoke among the residential and commuter populations was conducted and samples were taken from three undisturbed protected locations to the east of the WTC site (on Cor-tlandt. Cherry, and Market Streets). Analysis of samples provided for the determination of (a) chemical and physical characteristics of the material present in the dust and smoke... 

McCracken M., The climate effects of dust and smoke. International Seminar on Nuclear War , August 19-24, 1983, Erice (Sicily), Italy (to be published in the proceedings) (1983). 

Atmospheric aerosols are important nuclei for the condensation of water droplets (cloud, rain, fog). The dissolution of the water-soluble aerosol components contributes to the composition of the aqueous phase [e.g., NH4NO3, (NH4)2S04]. Aerosols may contain, in addition to the absorbed gases, a substantial fraction of atmospheric components that return ultimately to the earth surface by dry or wet deposition. The particle diameter ranges from 0.01 nm up to a few hundred micrometers. Primary atmospheric aerosols consist of dust and smoke particles while secondary aerosols are made up of constituents of the gas phase. 

A radiological attack is likely to entail use of what is often called a dirty bomb, in which conventional explosives are used to disperse radioactive material quickly across a wide area. Beyond the risk of immediate injury from the explosion itself, the primary initial danger is inhaling the radioactive material that is suspended within the dust and smoke from the explo-... 

Earth dust and smoke ----------------- blocked the sun for a long time. 

DeVan TD, Koh WP, Lee HP, et al. Vapor dust and smoke exposure in relation to adult-onset asthma and chronic respiratory symptoms The Singapore Chinese health study. Am J Epidemiol 2006 163(12) 1118—28. 

Two years later, the Mt. Sinai research group published three papers on their findings in three different medical journals.2 To sum up their conclusions The cause of intrauterine growth retardation in the infants was apparently not dust and smoke inhaled by the pregnant mothers, but maternal psychological stress and cortisol secretion effects, as indicated by measures of below-normal cortisol levels in their infants. 

Dust and smoke Metal oxides, PAH, soot Metal production, waste incineration, firing systems in general... 

It is remarkable that basically all sub-global air pollution problems (dust and smoke, sulfur and nitrogen pollution) in connection with fossil fuel combustion have been (or can be) solved by end-of-pipe technologies. Hence, the last and apparently insoluble problem remains CO2 emissions and the subsequent increase in the greenhouse effect. CCS technology is another end-of-pipe approach and far from any sustainable chemistry. But it seems the only practical way to start the abatement of CO2 emissions. 

Millions of tons of soot, dust, and smoke particles are emitted into the atmosphere of the United States each year. The average suspended particulate concentrations in the United States vary from about 0.00001 g/m of air in rural areas to about six times as much in urban locations. In heavily polluted areas, concentrations of particulates may increase to 0.002 g/m . 

In addition, certain devices are used for pollution control in industry. They either destroy contaminants or remove them (from an exhaust stream) so they are not emitted into the atmosphere. Several examples are provided. An electrostatic precipitator removes (collects) particles from a flowing gas, using the force of an induced electrostatic charge. It can remove fine particles such as dust and smoke from a stream of air. 

Process equipment items, in which material is transformed physically or chemically, for example crushers, reactors, screens, heaters, and heat exchangers. The process equipment is required to effect the physical and chemical changes and separations necessary to produce the desired products, and also to deal with any unwanted by-products, including waste, spillage, dust, and smoke. 

Others, one about 90 m east and some 60 m north of the main office building, described a cloud of dust and smoke coming round the southern end of Section 27 (Colquhoun, 1974). Another, some 500 m to the west, observed the development of the cloud from its initiation as a whisper of steam to its enlargement into a roaring jet going up river (i.e., south) and ending up like a fog across the car park (Ayre, 1974). 

High dust Failure of electrostatic precipitator/dust control equipment Dust and smoke pollution... 

It should be noted that other metal oxides used in humidity sensors did not show parameters comparable with parameters of Al Oj-based devices (Chen and Lu 2005). It was also found that metal oxide ceramics are highly sensitive to contaminants such as dust and smoke (Clayton et al. 1985 Nakajima et al. 1999). This means that they require maintenance, e.g., by heating them from time to... 

One difference between dry fine powders and colloids in liquids is that the low viscosity of air (and other gases) make hydrodynamic drag forces minimal for dry powders in many instances, except when the particles have very low density (such as dust and smoke) or the gas velocity is very high. However, fine particles in liquids are strongly influenced by hydrodynamic drag forces as described in Chapter 2 because the viscosity of liquids is much greater than that of gases. 

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