NOVELTY - The turbine has a turbine wheel connected to a turbine shaft provided with a magnetic coupling. An output shaft is provided with another coupling, where the couplings are arranged such that rotation of one of the couplings induces rotation of the other coupling. A fluid cooled barrier (73) is provided between the couplings and provided with conduits (69), which allow coolant i.e. refrigerant/organic fluid, to be delivered into the barrier and to be removed from the barrier. The conduits are connected to a chamber (95) within the barrier, where the chamber is located within a cylindrical wall.    USE - Axial turbine for use in a waste heat recovery system i.e. closed loop organic sub-critical/super-critical rankine cycle system, for an internal combustion engine i.e. diesel engine, of an engine assembly (all claimed) in a vehicle i.e. heavy duty diesel truck, for generating electricity.    ADVANTAGE - The barrier can prevent the coolant from flowing directly from the coolant inlet conduit to the coolant outlet conduit, where a passage for the coolant through the barrier transfers heat from the barrier to cool the barrier, and the coolant can prevent the barrier from overheating, thus preventing damage being caused to the barrier due to overheating and failure of the turbine. The barrier isolates pressurized lubricant at an interior side of the barrier from the turbine at an exterior side of the barrier, thus preventing leakage of the lubricant into the turbine.    DETAILED DESCRIPTION - The conduit includes a coolant inlet conduit (82) and a coolant outlet conduit (83). INDEPENDENT CLAIMS are also included for the following:    (1) a method for transferring power from a turbine shaft to an output shaft    (2) a method for using a turbine shaft to generate electricity.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic cross-sectional view of a barrier forming part of a turbine.    Conduits (69)    Fluid cooled barrier (73)    Flange (76)    Coolant inlet conduit (82)    Coolant outlet conduit (83)    Upper and lower surfaces of barrier (93, 94)    Chamber (95)