Abstract: A turbine includes a rotor having at least two rotor members for rotating in a plane, the rotor members being substantially diametrically arranged and attached to an axis situated substantially transversely to the plane, and drive unit coupled to the axis, wherein the rotor members include a fluid contact member, that is hingingly connected to an arm which is attached to the axis, characterized in that the fluid contact members are adapted to hinge between a fluid-active position in which the members project transversely to the plane and a fluid-transparent position in which the members extend mainly parallel to the plane.

Abstract: A traffic device (1), such as roadside post, provided with an indication element (3) having a visible area (2) and with a cleaning device (4) for cleaning the indication element (3), in which the cleaning device (4) comprises a plurality of cleaning elements (5), in which each cleaning element (5) comprises an elongate and flexible body (6) which, at one end, is attached to the traffic device (1) and from there extends in an unsupported manner and in which the body (6) of the cleaning elements (5) in each case extends along the visible area (2) in such a manner that the body (6) can swish across the visible area (2) with its length in order to clean it.

Abstract: An installation for increasing the daylight yield in a stadium provided with a playing surface, stands, and optionally a covering, includes an essentially vertical light-reflecting body to guide the light incident on the body towards the playing surface in the stadium. Preferably the reflecting body is arranged along the free peripheral edge of the covering of the stadium. In one embodiment the reflecting body includes a multi-layer construction of two corrugated sheets with a light-reflecting foil between them. The installation can increase the light yield in a covered stadium by between 30% and 50%.