Abstract: A novel rec-L-N-carbamoylase from Arthrobacter aurescens and its method of use for producing L-amino acids. The recombinantly produced L-carbamoylase is unexpectedly stable, so that an industrial method of producing L-amino acids can be established with it, in contrast to previously known L-carbamoylases.

Abstract: The present invention relates to ionically and covalently cross-linked polymers and polymer membranes having recurrent units of the general formula (1), wherein Q is a link, oxygen, sulfur, (2) or (3) and the R radical is a divalent radical of an aromatic or heteroaromatic compound, and which are characterized in that a) R radical comprises at least partially substituents of general formula (4A), (4B), (4C), (4D), (4E), (4F), (4G) and/or (4H), b) R radical comprises at least partially substituents of the general formula (5A) and/or (5B) and/or the R radical is at least partially a group of the general formula (5C) and/or (5D) and c) the R radical comprises at least partially bridges of the general formula (6) linking at least to R radicals together, R1, R2, R3, R4, R5, M, X, Y, Z and m having the herein-mentioned meanings.

Abstract: The present invention relates to polymer blends and polymer blend membranes which consist of a polymeric sulfonic acid and of a polymer which contains primary, secondary or tertiary amino groups, which are prepared via mixing of a salt of the polymeric sulfonic acid with the polymer which contains primary, secondary or tertiary amino groups. The invention further relates to the use of polymer blend membranes in membrane fuel cells, polymer electrolyte membrane fuel cells (PEM fuel cells) or direct methanol fuel cells (DMFC), in membrane electrolysis, in aqueous or non-aqueous electrodialysis, in diffusion dialysis, in the perstractive separation of alkenes from alkene/alkane mixtures (here the membranes are in the SO3Ag form, where the Ag+ forms a reversible complex with the alkene (→facilitated transport)), in pervaporative separation of water from water/organics mixtures, or in gas separation.

Abstract: A novel rec-L-N-carbamoylase from Arthrobacter aurescens and its method of use for producing L-amino acids. The recombinantly produced L-carbamoylase is unexpectedly stable, so that an industrial method of producing L-amino acids can be established with it, in contrast to previously known L-carbamoylases.

Abstract: The present invention relates to novel compatible binary and ternary cation-exchanger polymer and anion-exchanger polymer blend membranes.

Abstract: The invention relates to a fiber-reinforced ceramic body and a method for producing same. The ceramic body consists of a core and a boundary layer (93, 94) which is joined to the core and has at least one outer surface (96, 97) which can preferably be subjected to tribological stress. The core consists of one or more layers (92) of which at least one is reinforced with long fibers. The boundary layer (93, 94) is reinforced with short fibers. The fibers are preferably reaction-bonded in a matrix by melt infiltration and are made of high-temperature resistant fibers with covalent bonds on the basis of silicon, carbon, boron or nitrogen.

Abstract: A method is described for examining a solidifying and/or hardening material such as cement, concrete or the like, using ultrasound waves emitted by an ultrasound transmitter, which penetrate the solidifying and/or hardening material, are continuously measured and analyzed. During solidification and/or hardening of the material, the signal shapes of the ultrasound waves penetrating the material, are recorded. The change with time of the compression wave velocity and/or the relative energy of the ultrasound waves and/or the frequency spectra of the ultrasound waves is extracted from the ultrasound wave shapes during the entire course of solidification and/or hardening of the material. This change with time of the compression wave velocity and/or the relative energy of the ultrasound waves and/or the frequency spectra of the ultrasound waves is approximated through a compensating function, preferably the Boltzmann function.

Abstract: A diffuser for slowing down a fluid and a method for operating a diffuser is described. A channel of the diffusor has an inlet with a smaller flow cross section than a flow cross section of an outlet and at least one opening for receiving an energizing fluid to be transported selectively into the channel. Pulsations of the impact interface are suppressed effectively at all of the operating points by injecting the energization fluid. Pressures of the fluid moving in the diffusor are measured, and amplitudes and frequencies of the measured pressures are evaluated. Energizing fluid is fed into the diffusor if the amplitudes within a predetermined frequency band exceed a threshold value. The utilization ratio of the inventive diffuser is considerably improved as a result of such a measure.

Abstract: The present invention provides novel, economic processes for preparing nitrated and sulfonated polymers and aminated and sulfonated polymers. Also provided are the polymers prepared by these processes. The invention also provides for membranes comprising the polymers, methods for preparing the membranes and their use in electromembrane processes, particularly in fuel cells.

Abstract: A novel rec-L-N-carbamoylase from Arthrobacter aurescens and its method of use for producing L-amino acids. The recombinantly produced L-carbamoylase is unexpectedly stable, so that an industrial method of producing L-amino acids can be established with it, in contrast to previously known L-carbamoylases.

Abstract: The present invention provides a process for the preparation of ion-exchange membranes for use in electromembrane processes and ion-exchange membranes obtained from the process. The membranes are prepared from a solution, in a dipolar-aprotic solvent, containing (a) a polymeric sulfonic acid or a polymeric sulfonate salt of formula Polymer-SO3X, where X is H or a monovalent cation, and (b) a basic polymer containing primary, secondary or tertiary basic nitrogen. The dissolved polymer blend is spread in a thin layer onto a support, and the solvent is evaporated to form a polymeric film. The films produced by the process are particularly useful as ion-exchange membranes due to improved properties relative to the component polymers with regard to ionic conductivity, swelling permselectivity, and thermal resistance.

Abstract: The penetration depth of a machining laser beam into workpiece is continuously monitored in that a measuring laser beam is directed onto the vapor capillary that is generated in the workpiece by the machining laser beam.

Abstract: A position display instrument for light spot display on a map of the position of vehicles, in particular aircraft or helicopters. The instrument comprises a flat map holder for accommodating and holding map sheets in an exact position, a light transmitter located below the map holder for producing a light spot on the map sheet and movable in two coordinates by positioning means, a microcomputer to which the grid coordinates of the vehicle position are applied from a navigational computer and by which the positioning means are controlled, a memory for storing map data, said memory cooperating with the microcomputer, and display means which is connected to the microcomputer and by which the map sheet or map field required for the respective grid coordinates is displayed.

Abstract: A stepping motor turns 45.degree. for each step in response to a digital control signal different than the signals for other step adjacent thereto. An angle sensor produces a digital position indicating signal for sectors centered about the step positions and of the same magnitude as the angle between motor steps. The position indicating signal for a sector corresponds to the digital signal of the motor step that falls within that sector. An evaluation circuit comprising a microprocessor produces an error signal when, after a predetermined elapsed time after receipt of a control signal, a corresponding position indicating signal is not received. The evaluation circuit also checks for correspondence of signal within a minimum time after receipt of a control signal, and failing to find such correspondence assumes that the motor has not performed the directed step.