Fabric, pollution effect

The same applies to mineral oils and greases that are based on cmde oil. Certain greases that are deposited on outdoor cables in aluminium during their fabrication provide effective protection against possible atmospheric corrosion due to moisture and pollution for a very long time (several decades). 

Materials The damage that air pollutants can do to some materials is well known ozone in photochemical smog cracks rubber, weakens fabrics, and fades dyes hydrogen sulfide tarnishes silver smoke dirties laundry acid aerosols ruin nylon hose. Among the most important effects are discoloration, corrosion, the soiling of goods, and impairment of visibility. 

The major effects of air pollution on fabrics are soiling and loss of tensile strength. Sulfur oxides are considered to cause the greatest loss of tensile strength. The most widely publicized example of this type of problem has been damage to women s nylon hose by air pollution, described in newspaper accounts. The mechanism is not understood, but it is postulated that fine droplets of sulfuric acid aerosol deposit on the very thin nylon... 

Materials and Structures. Building materials have become soiled and blackened by smoke, and damage by chemical attack from acid gases in the air has led to the deterioration of many marble statues in western Europe. Metals are also affected by air pollution for example, S02 causes many metals to corrode at a faster rate. Ozone is known to oxidize rubber products, and one of the effects of Los Angeles smog is cracking of rubber tires. Fabrics, leather, and paper are also affected by S02 and sulfuric acid, causing them to crack, become brittle, and tear more easily. 

Yet it seems that emissions of all pollutants, including acid rain precursors, particulates, trace elements, and organics, should be limited as much as possible, even if the interrelationships of cause and effect are not yet clearly defined. The question is, however, how to limit emissions in a timely, economical, and technically effective manner without disrupting the industrial or social fabric of our nation. 

In addition [103,104], a new type of composite that combines DNA with silica components via a sol-gel method was described. The DNA-silica hybrid material is advantageous with respect to its mechanical and chemical stability in both aqueous and organic solvents. Similar to the previously described hybrids, the specific functions of the DNA molecules were retained and maintained the DNA-silica hybrid materials adsorb DNA-interactive chemicals from diluted aqueous solution. In another series of reports [105-109], DNA-loaded PSf microspheres were fabricated by means of a liquid-liquid phase separation technique. The release rate of DNA from the microspheres can be controlled by manipulating the microsphere structure. Increasing the polymer concentration causes lower porosity and smaller pores on the outer surface of the microspheres, and leads to a low release rate of DNA from the microspheres. The DNA-loaded PSf microspheres could effectively accumulate harmful DNA-intercalating pollutants and endocrine disruptors, as described in previous reports. 

Each is discussed in Sec. 17 of this handbook under Gas-Solids Separations. The effectiveness of conventional air-pollution-control equipment for particulate removal is compared in Fig. 22-25. These fractional efficiency curves indicate that the equipment is least efficient in removing particulates in the 0.1- to 1.0-pm range. For wet scrubbers and fabric filters, the very small particulates (0.1 pm) can be efficiently removed by brownian diffusion. The smaller the particulates, the more intense their brownian motion and the easier their collection by diffusion forces. Larger particulates (>1 pm) are collected principally by impaction, and removal efficiency increases with particulate size. The minimum in the fractional efficiency curve for scrubbers and filters occurs in the transition range between removal by brownian diffusion and removal by impaction. 

The chemistry we use in our everyday life is generally beneficial to us for example, processed foods, medicines, pharmaceuticals, scents, detergents, fibres and fabrics, plastics, processed metals, paints and wall coverings, dyestuffs, fuels, bricks and ceramics, improved food production by the use of fertilisers and insecticides, and many more. Society often forgets all of these, and it has become a fashionable thing to blame the scientists for all the pollution in our world. But we, the consumers, decide what we want for a better lifestyle. We want more effective drugs, materials and food processing, etc., but all development requires expensive and tested research. 

Several countries have introduced stringent emission limits (0.1 ng-TE/Nm ) for chlorinated dioxins and furans emitted from combustion sources, in particular solid waste incinerators, because of concerns over their adverse health effects. Technologies for reducing their formation and emission in incineration processes have been studied extensively and can be applied in modern incineration plants. Activated carbon injection and fabric filtration are currently practiced in many installations. However, to minimize capital cost, a more fundamental approach is needed to control and limit formation of these pollutants in incineration processes, e.g., involving the postcombustion zone, the combustion chamber, and waste feeding. ... 

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