Abstract: In a method and an evaluation device for the evaluation of projection data of an object being examined, which are determined along a trajectory in a multiplicity of projection positions relative to a co-ordinate origin, a particular trajectory function is determined for the projection positions, for each of a multiplicity of positions from a reconstruction region of dimension n by establishing an offset (d) and a direction vector at the co-ordinate origin, establishing a hyperplane of dimension n?1 which runs perpendicular to the direction vector and has an offset to the co-ordinate origin, establishing a number of intersection points where the hyperplane intersects the trajectory, establishing a derivative vector of the trajectory according to its trajectory path and calculating the derivative vector in the projection position, and establishing an absolute value of a scalar product between the derivative vector and the position and dividing the absolute value by the number.

Abstract: The invention relates to an optical sensor comprising an optical waveguide (1) and a light-sensitive element (4) for detecting light coupled out of the waveguide (1) and also various ring resonators (2), the ring resonators (2) being coupled optically to the mentioned waveguide (1) and, with the exception of at most one of the ring resonators (2), each having a means (5) for adjusting resonance frequencies of the respective ring resonator (2) and/or of the coupling between the ring resonator (2) and the waveguide (1) and at least two of the ring resonators (2) having different optical lengths in an initial state and being disposed for having their resonance frequencies influenced by means of different variables to be measured which are specific for each of these ring resonators (2). The invention refers furthermore to a method which can be implemented with a sensor of this type for detecting molecules of at least one substance.

Abstract: The invention relates to a reader antenna for use with radio frequency identification (RF ID) transponders. A reader and the transponder are connected to one another via a wireless interface. It is the object of the invention to provide a reader antenna for RFID systems whose transmission range is increased in comparison with a transmission range in a normal air environment without metallic influence with otherwise the same electrical and electromagnetic parameters. The reader antenna in accordance with the invention is provided with an antenna which is formed with a coil having at least one winding. The coil lies on a side of a carrier remote from a transponder and the carrier is made exclusively of a soft magnetic material.

Abstract: Aerodynamic window for a gas laser, whose active chamber emits a focussed ser beam and is flow connected by means of a beam passage opening with a window chamber connected to a vacuum pump and which has a beam exit opening in an outer area which is preferably under atmospheric pressure. In order to reduce the pumping power necessary for the aerodynamic window and improve the laser beam quality, the window is so constructed that the laser beam emitted by the active chamber has a first focus in the vicinity of the beam passage opening and is deflected onto a focussing mirror arranged in the window chamber and which gives the laser beam leaving the latter a second focus located in the vicinity of the beam exit opening.