Abstract: Preparation of optionally substituted dihydroisoquinolines. The present invention relates to a process for the preparation of optionally substituted dihydroi-soquinolines of the formula I.

Abstract: A method (100,200) of reducing a noise emitted by at least one of rotor blades of a wind turbine and a tower of the wind turbine, the wind turbine further including a drivetrain connected to the rotor blades via a hub of the wind turbine, the drivetrain comprising a gearbox, a generator, and a high speed shaft; wherein the gearbox and the generator are coupled by the high speed shaft; the method (100,200) including determining (110,210) an occurrence of the noise, and applying (120,230) a braking torque upon determining the noise, wherein the braking torque is applied to the high speed shaft during normal operation of the wind turbine to reduce the noise.

Abstract: A system and method for reducing audible tonality of a wind turbine caused by vibrations generated by the drivetrain assembly thereof includes a plurality of damping elements mounted at a plurality of locations on an inner surface of a tower of the wind turbine. The plurality of locations have vibration levels above a predetermined threshold. Thus, during operation of the wind turbine, the damping elements are configured to damp vibrations of the tower so as to reduce noise generated thereby.

Abstract: The present disclosure is directed to a system and method for reducing audible tonality of a wind turbine caused by vibrations generated by the drivetrain assembly thereof. The system includes a plurality of damping elements mounted at a plurality of locations on an inner surface of a tower of the wind turbine, the plurality of locations having vibration levels above a predetermined threshold. Thus, during operation of the wind turbine, the plurality of damping elements are configured to damp vibrations of the tower so noise generated thereby.