Abstract: Nanoscale, pyrogenically produced oxides and/or mixed oxides having a BET surface area of between 1 m2/g and 600 m2/g and a chloride content of less than 0.05 wt. % are produced by converting organometallic and/or organometalloid substances into the oxides at temperatures of above 200° C. The oxides may be used as a polishing agent in the electronics industry (CMP).

Abstract: Nanoscalar, pyrogenically produced yttrium-zirconium mixed oxide which has a BET surface area of between 1 and 600 m2/g, a total chloride content of less than 0.05 wt. % and does not exhibit a conversion into the monoclinic phase during storage is produced by atomizing yttrium compounds and zirconium compounds and reacting them in a flame. The mixed oxide can be used as ceramic raw material.

Abstract: Hydrophobic, pyrogenically produced oxides having a ratio of dimethylsilyl groups to monomethylsilyl groups of 100:0 to 50:50 are prepared by using siloxanes or methylsiloxane mixtures D3 to D9 as hydrophobing agent.

Abstract: Nanoscale, pyrogenically produced oxides and/or mixed oxides having a BET surface area of between 1 and 600 m2/g and a chloride content of less than 0.05 wt. % are produced by converting organometallic and/or organometalloid substances into the oxides at temperatures of above 200° C.

Abstract: Silica with the following physico-chemical properties:______________________________________ Specific surface m.sup.2 /g 80-400 Primary particle size nm 7-40 Tapped density g/l 50-300 pH value 3-10 Carbon content % 0.1-15 DBP number % <200 ______________________________________is produced by spraying a silica under intensive mixing, optionally with water or dilute acid at first and then with a surface-modifying reagent or a mixture of several surface-modifying reagents, then mixing, tempering, and subsequently destructuring/compressing and grinding.

Abstract: A system for controlling actuating members in the doors of motor vehicles has at least one electromotive actuating drive and at least one actuating element (switch, button) in the door of the motor vehicle, as well as a control unit located in the vehicle itself. The system employs only a two-wire connection between control unit and actuating drive. The control unit, in addition to an ordinary pole-reversing and evaluation circuit, furthermore contains a source of alternating voltage as well as means for connecting the alternating voltage and a decoder. At least two passive components (resistor, capacitor, coil) of different size are provided to be connected by the actuating element in parallel with the actuating drive into the two-wire connection.

Abstract: In a method and a circuit for the monitoring of electromotive setting elements which are connected to a bridge output stage, the actual values of the currents in the branches of the bridge are compared with the desired values which apply to the corresponding state of switching. Depending on the result of the comparison and the state of switching of the bridge output stage, an error possibly present is read from a table. It should be emphasized, in particular, in this connection that with only one bridge circuit, two motors which are connected in parallel can be completely monitored.