Various arrangements of a turbine for a rotating coalescer element of a crankcase ventilation system for an internal combustion engine are described. In some arrangements, the turbine is an impulse turbine, which is also known as a pelton turbine or a turgo turbine. The turbine is used to convert hydraulic power from a stream of pressurized fluid to mechanical power that is used to drive the rotating element. The turbine includes a non-wetting surface (e.g., an oleophobic or hydrophobic surface) that repels the pressurized fluid. The non-wetting surface may be achieved through plasma coating, fluoropolymer coating, micro-topography features, and the like. The non-wetting surface increases the power transmission efficiency from the stream of pressurized fluid to the turbine, thereby increasing the rotational speed of the rotating element compared to wettable surfaced turbines, which in turn increases the efficiency of the rotating element.

A method of coating an area of a wind turbine rotor blade comprises: defining an area to be coated on a surface of the blade, applying a first plurality of strips of masking tape to the surface of the blade proximate a first edge region of the defined area such that each strip is arranged adjacent to at least one other strip of said first plurality of strips, spraying a coating layer onto the defined area up to an innermost strip such that the innermost strip defines an edge of the coating layer, removing the innermost strip(s) to expose an uncoated region of the defined area between the edge of the coating layer and an innermost remaining strip and spraying a further coating layer over the previous coating layer and over the uncoated region up to said innermost remaining strip.

Various arrangements of a turbine for a rotating coalescer element of a crankcase ventilation system for an internal combustion engine are described. In some arrangements, the turbine is an impulse turbine, which is also known as a pelton turbine or a turgo turbine. The turbine is used to convert hydraulic power from a stream of pressurized fluid to mechanical power that is used to drive the rotating element. The turbine includes a non-wetting surface (e.g., an oleophobic or hydrophobic surface) that repels the pressurized fluid. The non-wetting surface may be achieved through plasma coating, fluoropolymer coating, micro-topography features, and the like. The non-wetting surface increases the power transmission efficiency from the stream of pressurized fluid to the turbine, thereby increasing the rotational speed of the rotating element compared to wettable surfaced turbines, which in turn increases the efficiency of the rotating element.

A method for sealing a joint gap between mutually joined elements, at least one of which is a sheet, by applying a joint gap seal involves preheating an area of the joined elements to which the joint gap seal is to be applied. A polymer powder is introduced into a plasma jet to form a plasma and powder jet directed towards the preheated region of the elements. Polymer particles melted in the plasma and powder jet are deposited as joint gap seal.