Abstract: The exoskeleton (10) for assisting surgical positioning is made of biocompatible material and formed to be substantially form-preserving. The exoskeleton (10) comprises a shell (11) having a coupling surface (15b) fitting to at least a part of a surface of an organ to be operated, and a guiding channel (13) is formed in the shell (11) at a predetermined position, said guiding channel having a predetermined orientation with respect to said shell and a predetermined cross-sectional area for directing a surgical tool to the organ to be operated.

Abstract: A system for handling short circuits on an electrical network comprising parallel operated units which are droop controlled for active and reactive power sharing and connected to each other via impedances and protection switches for detecting and handling a short circuit on the electrical network and for disconnecting the faulty part of the electrical network, said units including a DC-source and a grid forming voltage source inverter controlled by a cascaded control structure with an inner voltage control loop and a short circuit control for limiting the output current by changing the output voltage at the output terminals of the inverter as a function of the measured output current and a desired droop voltage provided by a droop controller for voltage and frequency power sharing.

Abstract: A system for handling short circuits on an electrical network comprising parallel operated units which are droop controlled for active and reactive power sharing and connected to each other via impedances and protection switches for detecting and handling a short circuit on the electrical network and for disconnecting the faulty part of the electrical network, said units including a DC-source and a grid forming voltage source inverter controlled by a cascaded control structure with an inner voltage control loop and a short circuit control for limiting the output current by changing the output voltage at the output terminals of the inverter as a function of the measured output current and a desired droop voltage provided by a droop controller for voltage and frequency power sharing.

Abstract: Disclosed is an optical brightening process for substrates comprising or consisting of synthetic polyamide in which the optical brightener is applied to the substrate by impregnation followed by heat treatment and wherein the brightener is applied in the presence of a compound or mixture of compounds of formula I,rnh.sub.2 iwherein R is --OH, --NR.sub.1 R.sub.2 or ##STR1## X being O, S or NH, and R.sub.1 and R.sub.2 being, independently, hydrogen, C.sub.1-6 alkyl or C.sub.2-4 hydroxyalkyl,Which compounds are in free base or acid addition salt form or, when R is OH, in O-sulphonic acid form, and preparations for use in such process.