Abstract: A height-adjustable actuation device comprises a drive for height adjustment of the actuation device; a casing having a longitudinal axis; a hollow spindle arranged in the casing for displacement of a first lid arranged on the hollow spindle along the longitudinal axis; an internal spindle arranged inside the hollow spindle for displacement of a second lid arranged on the internal spindle along the longitudinal axis, with the hollow spindle and the internal spindle being non-rotatably connected to each other in terms of a rotation about the longitudinal axis, and with the hollow spindle and the internal spindle being displaceable relative to each other along the longitudinal axis.

Abstract: The present invention relates to a mixture comprising at least one fluorescent whitening agent and at least one chelating agent, a composition for the surface treatment of paper or cardboard comprising said mixture, a process for the treatment of paper or cardboard by means of said composition and paper or cardboard obtainable through said process.

Abstract: A height-adjustable actuation device comprises a drive for height adjustment of the actuation device; a casing having a longitudinal axis; a hollow spindle arranged in the casing for displacement of a first lid arranged on the hollow spindle along the longitudinal axis; an internal spindle arranged inside the hollow spindle for displacement of a second lid arranged on the internal spindle along the longitudinal axis, with the hollow spindle and the internal spindle being non-rotatably connected to each other in terms of a rotation about the longitudinal axis, and with the hollow spindle and the internal spindle being displaceable relative to each other along the longitudinal axis.

Abstract: The invention provides a reflector antenna, especially for a communications satellite, having at least one fixed main reflector (102) with an essentially circular aperture. A fixed feed system (118) includes a horn radiator (108) with a rotationally symmetric radiation diagram and a fixed polarization direction. An auxiliary reflector may be arranged to be rotationally positionable around a main axis (E) and has a reflecting surface that is shaped as a partial surface of a nonrotationally symmetric ellipsoid with a low numerical eccentricity, which illuminates main reflector (102) elliptically with an ellipticity that is essentially constant regardless of the rotational position.

Abstract: A crash damper for vehicles comprises two securing elements, by way of which it can be secured to the bumper on the one hand and to the body of the vehicle on the other hand. In order to be able to compensate manufacturing tolerances of the body of the vehicle, an adjustment device is provided for adjusting the distance between the securing elements.

Abstract: A horn radiator with a grooved inner surface has a mode coupler for a TE.sub.01 wave and includes four cavity resonators embedded in the grooved surface of the horn and interconnected by an annular rectangular wave guide extending around the outer surface of the horn.