Abstract: Disclosed are a synthetic resin film envelope and a cultivating method for clean agricultural products. The synthetic resin film envelope is formed with a double-layer sectional structure having a thickness of about 0.02 to 0.1 mm and includes 60 to 90 weight percent of polypropylene resin having a melt index of 3 to 10 g/min at a temperature of 185° C., 1 to 20 weight percent of an antifogging agent, 1 to 10 weight percent of an antistatic agent, and 1 to 10 weight percent of white carbon.

Abstract: A tandem-type pump assembly having a first housing and a second housing. A first main pump and a second main pump are coaxially aligned and disposed in the first housing. A first driving shaft having a first end and a second end is rotatably supported in the first housing and coaxially interconnects the first main pump and the second main pump. A driving gear is fixed to the first end of the first driving shaft for rotation therewith. A second driving shaft is rotatably supported in the second housing for driving an auxiliary pump. A driven gear is fixed to the second driving shaft for rotation therewith and directly engages the driving gear.

Abstract: Disclosed is an ozone generator used for an O.sub.3 -TEOS process wherein a temperature regulator includes a sensor for measuring a temperature of an insulating oil and a controller for controlling an operation of a cooling system in response to a signal from the sensor. The cooling system maintains the insulating oil at a constant temperature for cooling discharge cells to prevent damage to the discharge cells when generating ozone.