Particles fumes

Fires - Radioactivity and the Detection of Fires, An electronic detector apparatus responds to changes in current flowing thru an ionization cell containing an o-particle source. The presence of smoke particles, fumes, or vapor in the cell will change the current flowing in the apparatus and activate an alarm... 

In the laboratory you may form mists or aerosols when a bottle of chemical is opened, when the contents of an open bottle are shaken, when chemicals are poured into other vessels, or when a chemical is spilled and hits a solid surface. Fumes are a colloidal suspension of solid or liquid particles. Grinding a metal can generate fiimes when the metal gets hot enough to vaporize but then quickly cools and recondenses to a solid in the form of tiny small particles. Fuming sulfuric acid and fuming nitric acid produce clouds of these acids over the surfaces of the liquids. Dusts are solid particles suspended... 

Aerosol. CoUoidal dispersions of liquids or solids in a gas. Distinctions are made among aerosols of liquid droplets (fog, cloud, drizzle, mist, rain, spray) and aerosols of solid particles (fume and dust). See reference [3]. 

Are there dust particles, fumes, mists, or vapors in the air ... 

After inhalation exposure, the absorption of Cd compotmds varies greatly depending on the physico-chemical properties of the Cd compounds involved, site of deposition in the lungs and particle size [22]. In the Itmgs, deposition, mucociliary clearance, and alveolar clearance determine the absorption of inhaled particles. Large particles, dusts (>10 pm in diameter) tend to be deposited in the upper airways, while small particles, fumes, cigarette smoke (approximately 0.1 pm in diameter) penetrate into the alveoli, which are the major site of absorption. Between 50-100% of Cd in the alveoli are transferred to the blood. In the average... 

Several properties of the filler are important to the compounder (279). Properties that are frequentiy reported by fumed sihca manufacturers include the acidity of the filler, nitrogen adsorption, oil absorption, and particle size distribution (280,281). The adsorption techniques provide a measure of the surface area of the filler, whereas oil absorption is an indication of the stmcture of the filler (282). Measurement of the sdanol concentration is critical, and some techniques that are commonly used in the industry to estimate this parameter are the methyl red absorption and methanol wettabihty (273,274,277) tests. Other techniques include various spectroscopies, such as diffuse reflectance infrared spectroscopy (drift), inverse gas chromatography (igc), photoacoustic ir, nmr, Raman, and surface forces apparatus (277,283—290). 

Finely ground cements often called ultrafine cements, having particles less than 10 p.m and an average size of 4 pm are used to grout soils with fine pore spaces, such as fine sand with a permeabiUty of lO " cm/s. These cements can be made with a wide combination of Pordand cement, slag, or siUca fume (72). 

In a gas stream cariying dust or fume, some degree of particle flocculation will exist, so that both discrete particles and clusters of adhering particles will be present. The discrete particles composing the clusters may be only loosely attached to each other, as by van der Waals forces [Lapple, Chem. Eng., 75(11), 149 (1968)]. Flocculation tends to increase with increases in particle concentration and may strongly influence collector performance. 

Because of their inherently high efficiency on dusts in all particle-size ranges, fabric filters have been used for collection of fine dusts and fumes for over 100 years. The greatest limitation on filter application has been imposed by the temperature limits of available fabric materials. The upper limit for natural fibers is about 90°C (200°F). The major new developments in filter technology that have been made since 1945 have followed the development of fabrics made from glass and synthetic fibers, which has extended the temperature limits to about 230 to 260°C (450 to 500°F). The capabihties of available fibers to resist high temperatures are still among the most severe limitations on the possible applications of fabric filters. 

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