Abstract: A method for measuring process parameters in liquid cultures in a plurality of microreactors of at least one microtiter plate includes continuously agitating the liquid cultures using an orbital agitator at least until the reaction is completed in all the microreactors. In order to allow process parameters also of such substances which themselves do not have any fluorescence activity to be measured with relatively low complexity and within a short time, 2D fluorescence spectra are recorded in a plurality of in particular different liquid cultures in the microreactors of agitated microplates. A device for carrying out the method is also disclosed.

Abstract: The invention puts forward a bidirectional DC-DC converter for high voltages that is as simple as possible and that entails as few losses as possible. The bidirectional DC-DC converter (1) converter comprises an input stage (2) to convert a DC input voltage into first AC voltage, a transformer (3) to transform the first AC voltage into a second AC voltage, and an output stage (4) to convert the second AC voltage into a DC output voltage, whereby, in order to provide the first and/or second AC voltage, at least one of the input stages (2) and/or output stages (4) comprises a branch of a multi-level converter (5) with a first number of active first semiconductor switches (61).

Abstract: A DC-DC converter having a primary side comprising at least three actively switched primary voltage bridges with several active switches for converting a DC input voltage into primary alternating voltages for each of the primary voltage bridges, and having a secondary side comprising at least three actively switched secondary voltage bridges with several active switches for converting the secondary alternating voltages into a shared DC output voltage for each of the secondary voltage bridges. The primary and secondary alternating voltages are each shifted by a phase angle ? with the periods T, and each of the primary and secondary voltage bridges is coupled to an appertaining phase via one or more transformers.

Abstract: There is provided a method for the activation of a fuel cell. An exemplary method comprises operating the fuel cell entirely or partially at least briefly in an electrolysis regimen during galvanic operation.

Abstract: The techniques described herein relate to a solar collector with variable heat release and to a method for operating such solar collectors. The solar collector comprises a housing and an absorber arranged in the housing for purposes of releasing heat to a heat-transfer medium that flows at least partially through the housing, whereby the housing has at least one transparent cover to allow incident sunlight to pass through onto the absorber and to modify the heat release to the environment, whereby the cover is arranged in the housing in such a way that at least the mean distance between the cover and the absorber can be varied in order to adjust the heat release. Increasing the mean distance leads to a decrease of the heat release to the environment, while reducing the mean distance leads to an increase of the heat release to the environment.

Abstract: The invention relates to a device for determining the mechanical leg axis of a femur. Said device is provided with a shaft (3) that comprises, on one of its ends, a securing device (5) that is connected to the shaft and that can be blocked at various angles, in order to obtain a fastening that can be blocked in an angle stable manner and that fastens the shaft (3) to the knee joint of a femur, and comprises a gripping element (10) on its other end. A force-torque measuring device (14) is arranged between the gripping element (10) and the shaft (3), said device enabling the longitudinal and/or transversal force components of force (Fz) exerted via the shaft (3) upon the knee joint to be measured by means of the gripping element (10) and/or torque produced thereby. The invention also relates to a method for determining the mechanical leg axis of a femur by means of the above mentioned device.

Abstract: The invention relates to a device for determining the mechanical leg axis of a femur. Said device is provided with a shaft (3) that comprises, on one of its ends, a securing device (5) that is connected to the shaft and that can be blocked at various angles, in order to obtain a fastening that can be blocked in an angle stable manner and that fastens the shaft (3) to the knee joint of a femur, and comprises a gripping element (10) on its other end. A force-torque measuring device (14) is arranged between the gripping element (10) and the shaft (3), said device enabling the longitudinal and/or transversal force components of force (Fz) exerted via the shaft (3) upon the knee joint to be measured by means of the gripping element (10) and/or torque produced thereby. The invention also relates to a method for determining the mechanical leg axis of a femur by means of the above mentioned device.

Abstract: A device (10) for acquiring data in the mouth of a patient, wherein the device (10) comprises an ultrasound sensor (20) and a support structure. The ultrasound sensor (20) is stored by means of the support structure when not in use and contains ultrasound deflection means (12) which are movable. A coupling body (21) is provided, which is arranged between the ultrasound deflection means (12) and a tooth area (1, 2, 3) or remaining tooth area to be swept over Excitation signals (14) are sent to the ultrasound sensor (20) and the ultrasound deflection means (12) are moved in order to thus produce an ultrasonic wave which sweeps over at least part of the tooth area (1, 2, 3) or remaining tooth area.