Abstract: A seat having a backrest and a seat cushion is provided with at least one adjusting element on both sides of the longitudinal center plane of the seat. By alternatingly actuating the adjusting elements in the two halves of the seat, mobilization of the spinal column of a seat user occurs. In order to increase the acceptance of such a mobilization, which requires comparatively long stroke lengths of the adjusting elements to achieve a physiological effectiveness, an accustomization phase occurs before the action phase. During the accustomization phase, the adjusting elements exercise, for example, only about half of the stroke during the action phase. Preferably, a transition phase may be interposed between the accustomization phase and the action phase.

Abstract: A seat having a backrest and a seat cushion is provided with at least one adjusting element on both sides of the longitudinal center plane of the seat. By alternatingly actuating the adjusting elements in the two halves of the seat, mobilization of the spinal column of a seat user occurs. In order to increase the acceptance of such a mobilization, which requires comparatively long stroke lengths of the adjusting elements to achieve a physiological effectiveness, an accustomization phase occurs before the action phase. During the accustomization phase, the adjusting elements exercise, for example, only about half of the stroke during the action phase. Preferably, a transition phase may be interposed between the accustomization phase and the action phase.

Abstract: A prewarning device for an induction melting furnace serves for warning of breakouts of molten metal on ceramic furnace linings of melting furnaces. The device has electrodes that may be arranged on the furnace lining in question which are divided into two groups of different polarity and are spaced apart from each other. The electrode groups can be connected to an evaluation unit in order to determine the electrical temperature-dependent resistance of the furnace lining. In order to permit a simple application of the electrodes on the outside of the furnace lining and assure a high reliability of indication of the entire system, at least a high reliability of indication of the entire system, at least one of the electrodes is arranged as an electrode network on a first side on a ceramic foil. Either the first side of the ceramic foil or the opposite side is arranged on the furnace lining.