Abstract: A piston-in-piston non-compressible unit is disclosed that utilizes an elastic volume to store and release energy with each stroke by varying the non-compressible fluid volumes in and out of the hydraulic unit.

Abstract: It is presented a method for controlling the instantaneous power output from a wind power plant. Wind speed and wind directions are determined, wherein an upper limit power output for the specific wind speed and wind direction is determined from a previously measured power output value at the same wind speed and wind direction, and wherein the power output of the wind power plant is controlled based on the determined upper limit power output. A wind power plant is also presented.

Abstract: A valve tester system is disclosed that comprises a valve tester assembly for rotating a valve stem of a valve. The valve tester assembly may include a support, a rotation element mounted on the support for rotating a valve during a rotation event, a control element for controlling aspects of the rotation event of the valve by the rotation element, and an element for detecting a location of the valve tester assembly during the rotation event of the valve. In some embodiments of the invention, the element for detecting the location of the valve tester assembly includes a Global Positioning Satellite (GPS) receiver. In some embodiments, the GPS receiver is integral with the control element.

Abstract: Improved techniques are provided for drilling a deviated borehole through earth formations utilizing a rotary bit powered by a drill motor, and for obtaining information regarding the borehole or earth formations while drilling. An inclinometer is positioned below the drill motor and within a sealed cavity of a housing fixed to a drill motor sub, and a transmitter within the sealed cavity forwards acoustic or radial wave signals to a receiver provided in a measurement-while-drilling tool. The MWD tool may be provided within a non-magnetic portion of the drill string, and further houses an accelerometer for sensing borehole direction. Both borehole inclination and directional signals are transmitted to the surface by the MWD tool, and the drilling trajectory is altered in response to the signals.