Abstract: A Francis turbine includes a waterway, an impeller disposed in the waterway, a distributor apparatus disposed in the waterway and an additional element for adjusting the flow of water through the turbine. The additional element is disposed in the waterway upstream of the impeller in the water flow direction, and the additional element includes a perforated metal sheet that may be brought into the waterway. A method for operating such a turbine is also provided.

Abstract: A Francis turbine includes a waterway, an impeller disposed in the waterway, a distributor apparatus disposed in the waterway and an additional element for adjusting the flow of water through the turbine. The additional element is disposed in the waterway upstream of the impeller in the water flow direction, and the additional element includes a perforated metal sheet that may be brought into the waterway. A method for operating such a turbine is also provided.

Abstract: The invention relates to an impeller for a Kaplan turbine, comprising the following features or components: a shaft, a plurality of blades; a hollow hub which is located on the free end of the shaft and which carries the blades; an adjustment device for rotating the blades around axes of rotation perpendicular to the axis of rotation of the shaft. The invention is characterized by the following features: the interior of the hub is connected to a source of compressed air; branch lines are provided inside the hub to supply the compressed air to bearings or other lubrication points for the adjustment device.

Abstract: An optical component includes an optical element, a mount for the optical element, and a temperature control device configured to control a temperature of a part of the mount based on at least one parameter selected from the group consisting of a coefficient of expansion of a substrate of the optical element, and a coefficient of expansion of a material of the mount.

Abstract: An optical component comprises at least one optically effective optical element which heats up when irradiated with light, and at least one holding element for the at least one optical element for holding the at least one optical element in a carrier structure, wherein the at least one optical element is connected to the at least one holding element in heat conducting fashion, and wherein the at least one holding element is at least partially provided with an active cooling system for carrying off heat from the at least one optical element. Additionally or alternatively, a temperature control device is provided which controls the temperature of at least a part of the mount of the optical element.

Abstract: An optical component comprises at least one optically effective optical element which heats up when irradiated with light, and at least one holding element for the at least one optical element for holding the at least one optical element in a carrier structure, wherein the at least one optical element is connected to the at least one holding element in heat conducting fashion, and wherein the at least one holding element is at least partially provided with an active cooling system for carrying off heat from the at least one optical element. Additionally or alternatively, a temperature control device is provided which controls the temperature of at least a part of the mount of the optical element.

Abstract: An optical component comprises at least one optically effective optical element which heats up when irradiated with light, and at least one holding element for the at least one optical element for holding the at least one optical element in a carrier structure, wherein the at least one optical element is connected to the at least one holding element in heat conducting fashion, and wherein the at least one holding element is at least partially provided with an active cooling system for carrying off heat from the at least one optical element. Additionally or alternatively, a temperature control device is provided which controls the temperature of at least a part of the mount of the optical element.

Abstract: An optical component comprises at least one optically effective optical element which heats up when irradiated with light, and at least one holding element for the at least one optical element for holding the at least one optical element in a carrier structure, wherein the at least one optical element is connected to the at least one holding element in heat conducting fashion, and wherein the at least one holding element is at least partially provided with an active cooling system for carrying off heat from the at least one optical element. Additionally or alternatively, a temperature control device is provided which controls the temperature of at least a part of the mount of the optical element.