Abstract: A method for metering a reagent into a flowing medium includes adjusting a quantity of a reagent to be metered per unit of time into a flowing medium as a function of a thickness of a reaction zone in a catalytically active material. An apparatus for metering a reagent into a flowing medium includes a control unit, a device associated with the control unit for detecting a thickness of a reaction zone, and a metering device associated with the control unit for introducing a reagent into a flowing medium upstream of a catalytic converter as seen in flow direction of the medium. The control unit adjusts a quantity of the reagent to be metered into the flowing medium per unit of time by the metering device, as a function of a thickness of the reaction zone.

Abstract: A catalytic converter assembly for nitrogen oxide reduction in the exhaust gas of an internal combustion engine, in particular a Diesel engine, includes a catalytic converter through which exhaust gas can flow in a given flow direction. The catalytic converter has a catalyst carrier and a catalytically active layer. The catalytic converter has a reducing agent storage capacity per unit of length being increased in the given flow direction.

Abstract: A method for metering a reagent into a flowing medium includes adjusting a quantity of a reagent to be metered per unit of time into a flowing medium as a function of a thickness of a reaction zone in a catalytically active material. An apparatus for metering a reagent into a flowing medium includes a control unit, a device associated with the control unit for detecting a thickness of a reaction zone, and a metering device associated with the control unit for introducing a reagent into a flowing medium upstream of a catalytic converter as seen in flow direction of the medium. The control unit adjusts a quantity of the reagent to be metered into the flowing medium per unit of time by the metering device, as a function of a thickness of the reaction zone.

Abstract: A method for the controlled introduction of a reducing agent into a nitrogen oxide-containing exhaust gas leaving an internal combustion engine through an exhaust line having a catalytic converter built in for reducing nitrogen oxide, includes detecting at least one operation-relevant parameter of the exhaust gas, of the catalytic converter and optionally of the engine to determine the nitrogen oxide rate. An intermediate value is determined for the reducing agent rate as a function of the nitrogen oxide rate. The intermediate value is reduced by a rate of the reducing agent desorbed by the catalytic converter or raised by a rate of the reducing agent adsorbed by the catalytic converter. An apparatus for performing the method includes a control unit. A device detects at least one operation-relevant parameter of the exhaust gas, of the catalytic converter and optionally of the engine. A reducing agent supply unit introduces the reducing agent into the exhaust line upstream of the catalytic converter.

Abstract: A sensor determines a course of concentration of an adsorbent substance, such as ammonia NH.sub.3, diffusing out of a flow medium through a surface of a sensor material into the sensor material, as a function of a distance from the surface. Individual pairs of contacts are connected to supply leads and are disposed in the sensor material and optionally on the surface of the sensor material, for determining electrical conductivity of the sensor material between the contacts of the individual pairs of contacts.

Abstract: A catalytic converter includes a metal carrier body, an adhesion-promoting intermediate layer in the form of an oxide film applied to the carrier body and a catalytically active layer applied to the intermediate layer. A method for producing a catalytic converter includes heating a metal carrier body in an oxidizing atmosphere to form an adhesion-promoting intermediate layer in the form of an oxide film on the carrier body and applying a catalytically active layer to the intermediate layer.

Abstract: A Catalyst for reducing the nitrogen oxides in flue gases by a reducing agent and a catalytically active composition are described. The catalyst increases resistance to catalyst poisons such as arsenic trioxide. The composition contains 60-90% by weight of titanium, 10-30% by weight of molybdenum, and 0.2-10% by weight of vanadium, as their respective oxides. A very pure titanium dioxide having less than 500 ppm of calcium and less than 100 ppm of iron, being 60% in the anastase modification. It has a mean particle size of 10 to 100 nm, a mean pore radius of 10 to 30 nm and a BET surface of 10 to 80 m.sup.2 per gram. The catalyst is prepared by wet-grinding a suspension of the titanium dioxide with the vanadium pentoxide and molybdenum trioxide in stated proportions. The suspension is then dried and precalcined for several hours at 450.degree. to 550.degree. C. The precalcined material is comminuted to diameters smaller than 180 .mu.m.

Abstract: A catalyst for reducing the nitrogen oxides in flue gases by a reducing agent and a catalytically active composition is described. The catalyst increases resistance to catalyst poisons such as arsenic trioxide. The composition contains 60-90% by weight of titanium, 10-30% by weight of molybdenum, and 0-10% by weight of vanadium, as their respective oxides. A very pure titanium dioxide having less than 500 ppm of calcium and less than 100 ppm of iron, and being 60% in the anastase modification. It has a mean particle size of 10 to 100 nm, a mean pore radius of 10 to 30 nm and a BET surface of 10 to 80 m.sup.2 per gram. The catalyst is prepared by wet-grinding a suspension of the titanium dioxide with the vanadium pentoxide and molybdenum trioxide mill in stated proportions. The suspension is then dried, and precalcined for several hours at 450.degree. to 550.degree. C. The precalcined material is comminuted to smaller than 180 .mu.m.

Abstract: A catalyst material for nitrogen oxide reduction in flue gases in the presence of ammonia, comprising hydrothermal titanium dioxide and the additives of vanadium oxide and one or more oxides of the elements tungsten, phosphorus, sulfur, chromium, zirconium, magnesium, copper, cobalt, iron, and uranium, which hydrothermal titanium dioxide and additives material is activated by grinding.

Abstract: Catalytic material for reducing nitrous oxides in flue gases in the presence of ammonia in which titanium oxide is used as the starting material and the latter is milled together with vanadium oxide and one or more oxides of the elements tungsten, molybdenum, phosphorus, chromium, copper, iron, uranium and is thereafter subjected to at least one thermal treatment. Tungsten and molybdenum are substituted here entirely or partially by phosphorus in the form of its oxides or phosphates.

Abstract: Ceramic cold conductors based on barium titanates having the general formula:(Ba.sub.1-x M.sup.II)O.z(Ti.sub.1-y M.sup.IV y)O.sub.2wherein M.sup.II is selected from the group consisting of Ca, Mg, Sr and Pb; M.sup.IV is selected from the group consisting of Sn and Zr; x and y are numerals, the sum of which does not exceed one and z is a numeral in the range of 1.005 to 1.

Abstract: A low porosity sintered polycrystalline silicon film is produced by grinding initial silicon material in a non-oxygen-containing liquid, such as decahydronaphthalene, to an average grain size corresponding to a specific surface of at least 50 m.sup.2 /g; thickening the so-attained grinding mass with a non-oxygen-containing material, such as polyisobutylene and/or polyethylene in a suitable solvent, so as to attain a viscosity in the resultant slip suitable for drawing a film from such slip, and drawing a film from such slip, optionally dividing the film into desired sized pieces, and sintering the resultant film or pieces.

Abstract: The invention provides an improved method for producing plate-shaped or tape-shaped silicon crystal bodies having pillar-like structures therein which are equivalent to columnar structures comprising conducting the sintering process, for purposes of particle enlargement, in a gas atmosphere comprised of argon and a minimum amount of hydrogen. In a preferred embodiment, the hydrogen concentration in such atmosphere is about 6% by volume. The so-produced silicon bodies are useful for further processing into large-surface solar cells.

Abstract: A capacitor dielectric with inner blocking layers is disclosed wherein the portion of copper located in intermediate layers between the crystallites is enriched toward the crystallite surfaces. The dielectric is produced by a heating speed of 200.degree. to 800.degree. C./h towards a sinter temperature, and a cooling-off speed of 10.degree. to 100.degree. C./h to about 350.degree. C. below the sinter temperature.

Abstract: A capacitor dielectric is disclosed with inner blocking layers in which two crystalline main phases are present in about equal portions in order to achieve an improvement in the loss factor of the insulation resistance, the voltage dependency of the dielectric constants and of the insulation resistance, and to achieve tighter manufacturing tolerances.

Abstract: A capacitor dielectric with inner blocking layers is disclosed wherein the portion of copper located in intermediate layers between the crystallites is enriched toward the crystallite surfaces. The dielectric is produced by a heating speed of 200 to 800.degree. C/h towards a sinter temperature, and a cooling-off speed of 10 to 100.degree. C/h to about 350.degree. C below the sinter temperature.

Abstract: A ceramic compound having the formula (La.sub.x A.sup.+2.sub.1-x).sub.2 (Ti.sub.x B.sup.+5.sub.1-x).sub.2 O.sub.7 wherein A.sup.+2 is a positive divalent element selected from the group consisting of Ba, Ca, Cd, Mg, Sr and mixtures thereof and B.sup.+5 is a positive pentavalent element selected from the group consisting of Sb, Mo, Nb, Ta, W and mixtures thereof and x is a numeral ranging from 0.70 to 0.99. This compound is characterized by a relatively small temperature coefficient of permittivity, a relatively high insulation resistance, a relatively low loss factor and is compatible with relatively low cost noble metals, making it useful for forming dielectric elements in monolithic multi-layer capacitor elements.

Abstract: Ceramic electrical resistors having a positive temperature-resistance coefficient, consisting of barium titanate with an atomic excess of titanium, and having a ferroelectric perowskite structure, the resistor being conductive by the presence therein of a rare earth dopant, the resistor also containing one or more of the following elements: cobalt, chromium, nickel, vanadium, manganese and copper. The resistor composition also desirably containing significant amounts of silicon.