Abstract: A method for monitoring a semiconductor element in a semiconductor module, wherein the semiconductor module has feed lines contacting the semiconductor element, includes arranging a magneto-optical sensor in a region of the semiconductor element or of at least one of the feed lines, reflecting a polarized light signal from the magneto-optical sensor or transmitting a polarized light signal through the magneto-optical sensor, and determining a current from a polarization of the reflected or transmitted light signal.

Abstract: A reactor configured to clean ballast water on ships includes a reactor housing having an inlet and an outlet and a reactor tube in the reactor housing providing a fluid connection between the inlet and the outlet. The reactor tube includes an inner wall having a plurality of rounded recesses extending longitudinally from a first end of the reactor tube to a second end of the reactor tube, and the rounded recesses each have a substantially constant cross section from the first end of the reactor tube to the second end of the reactor tube. A radially inwardly projecting ridge extends between each circumferentially adjacent pair of the rounded recesses.