Abstract: A method for manufacturing an ultrasonic transducer for use in a fluid medium is described. The ultrasonic transducer includes at least one transducer core having at least one acoustic-electric transducer element. The ultrasonic transducer furthermore includes at least one housing which at least partially surrounds the transducer core and which has at least one opening facing the fluid medium. In the method, at least one sealing film is stretched and connected to the housing in the stretched state in such a way that the sealing film at least partially seals the opening.

Abstract: An ultrasonic transducer for use in a fluid medium includes at least one housing, e.g., a sleeve, which has at least one interior space, and at least one transducer core having at least one electroacoustic transducer element is accommodated in the interior space. The housing has a housing wall at least partially enclosing the transducer core using at least one hollow space.

Abstract: An ultrasonic transducer for use in a fluid medium includes at least one housing having at least one inner space, at least one transducer core accommodated in the inner space, having at least one electroacoustic transducer element. The housing has at least one opening facing the fluid medium. The opening is covered at least partially by at least one sealing foil. An edge of the sealing foil is sealed by at least one sealing material.

Abstract: A vacuum pump comprises pumping elements arranged in a pumping chamber. An electric motor drives the pumping element. A frequency inverter is provided for changing the rotational speed of the electric motor. The frequency inverter is arranged in a frequency inverter housing immediately connected to the pump housing. An air cooler and a liquid cooler are arranged in the frequency inverter housing to cool the frequency inverter.

Abstract: An ultrasonic flow sensor for detecting a flow of a fluid medium in a flow tube includes at least one first ultrasonic transducer, at least one second ultrasonic transducer, and at least one waveguide configured to conduct ultrasonic waves between the at least one first ultrasonic transducer and the at least one second ultrasonic transducer by reflection on walls of the waveguide, and to enable the fluid medium to flow through. The ultrasonic waves are able to propagate between the first ultrasonic transducer and the second ultrasonic transducer on at least two ultrasonic paths. Sound energies of the ultrasonic waves transmitted on the at least two different ultrasonic paths differ from one another by no more than a factor of 100.

Abstract: An ultrasonic transducer for use in a fluid medium includes at least one transducer core having at least one electroacoustic transducer element, and further includes at least one housing having at least two housing parts. At least one first housing part at least partially encloses the transducer core such that a rear side of the electroacoustic transducer element which faces away from the fluid medium is accessible. Furthermore, at least one second housing part is connected to the first housing part. The ultrasonic transducer is essentially terminated by the second housing part on its side, which faces away from the fluid medium.

Abstract: A method for measuring a propagation time difference includes: sending a transmitted ultrasound pulse, which is provided with a transmission reference instant and which includes an envelope and a carrier frequency, into a spatial region and receiving a received ultrasound pulse that corresponds to the transmitted ultrasound pulse transmitted. A coarse time difference is provided by comparing the transmission reference instant with an envelope of the received ultrasound pulse, for at least two cycles of transmission/reception in opposite directions of transmission. A fine time difference is provided by comparing the transmission reference instant with an instantaneous variation of the received ultrasound pulse, for the at least two cycles of transmission/reception in opposite directions of transmission.

Abstract: An ultrasonic transducer for use in a fluid medium is proposed. The ultrasonic transducer includes at least one transducer core which has at least one acoustic/electric transducer element, in particular a piezoelectric transducer element. The ultrasonic transducer furthermore includes at least one housing, at least one housing opening being at least partially sealed against the fluid medium with the aid of a sealing film which is connected to the transducer core. The sealing film has at least one expansion deformation which is configured to permit a relative movement between the transducer core and the housing.

Abstract: An ultrasonic transducer for use in a fluid medium includes at least one transducer core having at least one acoustic/electric transducer element. The ultrasonic transducer furthermore includes at least one decoupling element which is configured to reduce a structure-borne noise coupling between the transducer core and a housing. The decoupling element includes at least one porous plastic material, in particular a foamed plastic material. The porous plastic material includes at least one thermosetting polymer and/or at least one thermoplastic.

Abstract: A screw vacuum pump, in particular for compression against atmospheric pressure, comprises a pump housing defining a suction chamber. Two meshing screw rotors are arranged in the suction chamber. Further, an overpressure outlet provided, which comprises an overpressure opening in a side wall of the suction chamber. Further, an overpressure valve is arranged in the overpressure outlet. The width (b) of the overpressure opening in the longitudinal direction of the screw rotors is smaller than or equal to a tooth width (B) of the screw rotors.

Abstract: An ultrasonic transducer for use in a fluid medium includes at least one piezoelectric transducer element, at least one matching body for the promotion of a vibrational coupling between the piezoelectric transducer element and the fluid medium, and at least one compensating body situated between the piezoelectric transducer element and the matching body for the reduction of thermal stresses, the compensating body having a coefficient of thermal expansion that is between a coefficient of thermal expansion of the piezoelectric transducer element and a coefficient of thermal expansion of the matching body.

Abstract: A method for treating a fluid is provided using a particulate material in the form of a deposited layer having an upstream side and a downstream side wherein a flow of the fluid is directed through the deposited layer from the upstream to the downstream side at a first temperature. The method includes reconditioning the deposited layer and then resuming treatment of the fluid, wherein reconditioning comprises heating the deposited layer to a second temperature; and cooling the deposited layer to a third temperature at an average cooling rate in the range of up to about 20° C./min.

Abstract: An ultrasonic transducer is described for use in a fluid medium. The ultrasonic transducer includes at least one piezoelectric transducer element and at least one matching element for promoting an oscillation injection between the piezoelectric transducer element and the fluid medium. The ultrasonic transducer also includes a housing (112), the piezoelectric transducer element being inserted in the housing. The housing has at least one opening facing the fluid medium, the matching element being inserted at least partially into the opening. The ultrasonic transducer also has at least one sealing element, which seals at least one intervening space between the matching element and the housing in such a way that an inner space of the housing is at least largely sealed from the fluid medium.

Abstract: A method for manufacturing an ultrasonic transducer for use in a fluid medium is described. The ultrasonic transducer includes at least one transducer core having at least one acoustic-electric transducer element. The ultrasonic transducer furthermore includes at least one housing which at least partially surrounds the transducer core and which has at least one opening facing the fluid medium. In the method, at least one sealing film is stretched and connected to the housing in the stretched state in such a way that the sealing film at least partially seals the opening.

Abstract: A printing press includes a first rotary body with a first bearer ring and a second rotary body with an axle which eccentrically supports a second bearer ring. The second bearer ring is in rolling contact with the first bearer ring and is rotatably coupled to the second rotary body.

Abstract: A method for gluing components is provided, forming an adhesive layer which is capable of functioning, at least in a temperature range of ?100° C. to ?160° C., wherein the adhesive layer is obtained from a curable reactive resin system. The reactive resin system includes an epoxy resin component and polymer particles dispersed in the epoxy resin component, the dispersed polymer particles furthermore including addition-crosslinked silicone elastomer. Also provided is the use of a reactive resin system for gluing piezoelectric ceramics and/or permanent magnets including rare earth elements and a component configuration including a piezoelectric ceramic, an impedance matching layer and an adhesive layer in contact with the piezoelectric ceramic and the impedance matching layer.

Abstract: A device for producing a current pulse includes supply terminals for providing a power supply voltage, and a switch which is situated in a control current branch between the supply terminals, which switch is configured to switch a control current through the control current branch as a function of an actuation signal. The device also has a current mirror having a control transistor and a signal transistor, the control transistor being situated in series to the first switch in the control current branch, and the signal transistor being configured to provide the current pulse as a function of the control current through the control transistor.

Abstract: An ultrasonic transducer for use in a fluid medium includes at least one transducer core having at least one acoustic/electric transducer element. The ultrasonic transducer furthermore includes at least one decoupling element which is configured to reduce a structure-borne noise coupling between the transducer core and a housing. The decoupling element includes at least one porous plastic material, in particular a foamed plastic material. The porous plastic material includes at least one thermosetting polymer and/or at least one thermoplastic.

Abstract: A method which allows especially the extrapolation of the measured value at the upper and lower end of a measuring range where normally no direct measurement range where normally no direct measurement is possible by superposition of interfering signals, for example by reflection on a radar antenna. In the presence of strong interference signals, for example by reflection of a radar antenna. In the presence of strong interference signals, which are for example caused by the natural resonance of the container or neck in which the measuring device is mounted, the direct level indicator signal can be regularly used if it has a high amplitude caused by a superposition with the interfering signal lies between two interfering signals and does not extend beyond these, the level indicator value can be interpolated by the shift of the signals from the point of reflection.

Abstract: Method for preparing (S)(+)phenyl acetic acid derivatives having the general formula (I): wherein R1 is a linear or branched alkyl group with 1-6 carbon atoms or substituted benzyl group, and R2 is methyl, ethyl or propyl group said method, characterised in that a compound of the general formula (II): wherein R1 is as given above, and R3 is a nucleofuge, or a suitable salt of a compound of the general formula (II) is reacted with a compound having the general formula (III): wherein R2 is as given above, and R4 is hydrogen or a nucleofuge that can be removed hydrolytically, and the protective group R4 that may be present, may be subsequently removed hydrolytically.