Abstract: In an operating and diagnostic method for an SCR exhaust gas aftertreatment system which has an SCR catalytic converter with ammonia storage capacity, a signal of an exhaust gas sensor that is sensitive to nitrogen oxide and ammonia and is arranged downstream of the SCR catalytic converter, is measured. In a normal operating mode, ammonia is supplied to the SCR catalytic converter corresponding to a filling level model for ammonia stored in the SCR catalytic converter, in such a way that the ammonia filling level of the SCR catalytic converter is held at least approximately at a predefinable nominal value (or value range). The normal operating mode is interrupted if an exhaust gas sensor signal that exceeds a predefinable first limit value, is registered, and the set urea dosing rate is increased by a predefinable degree in relation to the value provided in the normal operating mode.

Abstract: The invention relates to In an operating and diagnostic method for an SCR exhaust gas aftertreatment system which has an SCR catalytic converter with ammonia storage capacity, a signal of an exhaust gas sensor that is sensitive to nitrogen oxide and ammonia and is arranged downstream of the SCR catalytic converter, is measured. In a normal operating mode, ammonia is supplied to the SCR catalytic converter corresponding to a filling level model for ammonia stored in the SCR catalytic converter, in such a way that the ammonia filling level of the SCR catalytic converter is held at least approximately at a predefinable nominal value (or value range). The normal operating mode is interrupted if an exhaust gas sensor signal that exceeds a predefinable first limit value, is registered, and the set urea dosing rate is increased by a predefinable degree in relation to the value provided in the normal operating mode.

Abstract: A method and apparatus for detecting the presence of a prescribed heat exchanger, such as a catalytically active radiator, in a motor vehicle are performed during operation of the motor vehicle. The temperature of a heat-exchanger medium is observed together with further current operationally relevant parameters of the motor vehicle for a prespecified time window. An expected temperature gradient over time of the heat-exchanger medium is detected, as well as the current temperature gradient over time of the temperature of the heat-exchanger medium. The presence of a prescribed heat exchanger is detected taking into account the expected temperature gradient and the current temperature gradient.

Abstract: A method and apparatus for detecting the presence of a prescribed heat exchanger, such as a catalytically active radiator, in a motor vehicle are performed, during operation of the motor vehicle. The temperature of a heat-exchanger medium is observed together with further current operationally relevant parameters of the motor vehicle for a prespecified time window. An expected temperature gradient over time of the heat-exchanger medium is detected, as well as the current temperature gradient over time of the temperature of the heat-exchanger medium. The presence of a prescribed heat exchanger is detected taking into account the expected temperature gradient and the current temperature gradient.

Abstract: In a device for determining an exhaust gas recirculation rate (EGR) in an internal combustion engine, wherein the device includes a sensor unit, which in a first region is exposed to an exhaust-gas atmosphere from an exhaust gas recirculation line and in a second region is exposed to an exhaust gas/fresh air atmosphere in an intake line of the internal combustion engine downstream of a location where the exhaust gas recirculation line opens into the intake line, the sensor unit disposed in the intake line is tubular with the inner side of the sensor unit being exposed to the exhaust gas atmosphere and the outer side of the sensor unit being exposed to the exhaust gas/fresh air atmosphere. The sensor unit is preferably positioned centrally within the intake line away from the wall of the intake line.

Abstract: The invention relates to a nozzle needle 4 of an injection nozzle 1, which is disposed within an injector housing and is biased against a housing shoulder 5 by way of a spring 2. A piezo-element 7 is between the spring 2 and the housing shoulder 5, to determine the nozzle needle path during opening and closing of the nozzle opening 3. For this purpose, the piezo-element 7 has two electrical connectors 8.1, 8.2 in the region of the faces 7.1, 7.2, respectively.

Abstract: A new high-temperature solid electrolyte fuel cell comprising an electrolyte layer between two electrode layers is obtainable by a process comprising the steps: (i) applying electrolyte particles in a screen printing paste on an unsintered electrolyte substrate and sintering the thus produced structure, (ii) depositing a nano-porous electrode thin layer by a sol-gel-process or an MOD-process on the structure obtained according to step (i) and thermal treatment of the thus coated structure. The fuel cell optionally has an electrolyte boundary layer on the structured screen printed electrolyte layer which is applied by an MOD process.

Abstract: In a device for determining an exhaust gas recirculation rate (EGR) in an internal combustion engine, wherein the device includes a sensor unit, which in a first region is exposed to an exhaust-gas atmosphere from an exhaust gas recirculation line and in a second region is exposed to an exhaust gas/fresh air atmosphere in an intake line of the internal combustion engine downstream of a location where the exhaust gas recirculation line opens into the intake line, the sensor unit disposed in the intake line is tubular with the inner side of the sensor unit being exposed to the exhaust gas atmosphere and the outer side of the sensor unit being exposed to the exhaust gas/fresh air atmosphere. The sensor unit is preferably positioned centrally within the intake line away from the wall of the intake line.