Abstract: A sealing arrangement including a ring gasket having at least one dynamically stressed sealing lip which is in sealing contact with a first machine element. A multipole ring made of a magnetized elastomer material is connected to a carrier ring and is moveable past an rpm sensor for detecting rotational movement of the first machine element relative to a second machine element. The carrier ring has an essentially C-shaped profile which is open axially in the direction of the ring gasket and is connected in a rotationally fixed manner to the first machine element. A first leg of the carrier ring is connected to the first machine element has an end which is adjacent the sealing lip at an axial distance.

Abstract: A radial shaft seal with a sealing disk made of a polymer material which curves towards a space that is sealed as the sealing disk radially approaches a shaft with respect to which it forms a seal. The sealing disk has a first surface profiling on the side facing the shaft and a second surface profiling on the side facing away from the shaft, the first surface profiling being formed by sawtooth recesses arranged adjacent to one another axially at a distance. The first bordering surfaces of the recesses facing the space to be sealed form a smaller angle with the shaft than second bordering surfaces of the recesses facing away from the space to be sealed. The second surface profiling is formed by essentially U-shaped recesses which are open on the side facing away from the shaft and are arranged adjacent to one another with an axial distance between them.

Abstract: Acicular .gamma.-iron(III) oxide is manufactured by reacting an iron(II) salt solution with aqueous solutions of alkali metal hydroxides and oxidizing the resulting suspension of iron(II) hyroxides in 3 stages. In the first stage not more than 8 percent by weight of the iron(II) hydroxide originally present is oxidized over a period of 0.5 to 4 hours, in the second stage from 25 to 55 percent by weight over a period of 1.5 to 6 hours and the remainder thereof in a third stage. Following this oxidation, the goethite formed is reduced to magnetite, which is then oxidized to acicular .gamma.-iron(III) oxide.