A method for forming a top for a cooling tower having a bottom wall at least one opening therein for accommodating an air current generator. The composition may further include one or more green linkers. The incoming wash oil flow rate to the distillation unit can be automatically adjusted based on the wash oil entrainment estimation while the distillation unit is operating. In a further embodiment a second arc source is activated to coat the substrates while a first arc source is activated, and the magnetic deflecting system for the first arc source is deactivated to confine plasma to the cathode chamber but permit electrons to flow into the coating chamber for plasma immersed treatment of the substrates.