Despite such opposition, the first meters were installed by the Dual Parking Meter Company beginning in July 1935; they cost a nickel an hour, and were placed at 20-foot intervals along the curb that corresponded to spaces painted on the pavement.
The single solution for everything in your air. Many air cleaning systems filter out particles. Some combat germs, and some fight odors. But only the PureAirâ¢ Air Purification System addresses all three types of indoor air pollutants.
Dissolved air flotation. Dissolved air flotation (DAF) is a water treatment process that clarifies wastewaters (or other waters) by the removal of suspended matter such as oil or solids. The removal is achieved by dissolving air in the water or wastewater under pressure and then releasing the air at atmospheric pressure in a flotation tank basin.