 More fuel flows in to replace the volume previously kept by the waste gas, and the reaction is allowed to continue.A well-known application of ultrahydrophobic surfaces is on heat exchangers, where they can improve droplet shedding and even cause jumping-droplet condensation, with potential for powerplants, heating and air conditioning, and desalination.Rare earth oxides, which are found to exhibit intrinsically hydrophobic surfaces, offer an alternative to surface coatings, allowing the development of thermally stable hydrophobic surfaces for heat exchangers operating at high temperature Ultrahydrophobic desalination membranes for membrane distillation have also been fabricated for improved fouling resistance, which can be fabricated effectively with chemical vapor deposition.