Abstract: The present invention relates to a detection unit comprising detection means for detecting the occurrence of an event. The detection unit further comprises processing means for controlling the operation of the detection unit and communication means for transmitting and receiving activation signals for interacting with further detection units. The processing means are designed for placing the detection unit into active mode upon receipt of an incoming activation signal, and furthermore for transmitting, in the active mode, an outgoing activation signal to at least one of said further detection units upon detection of an event and placing the detection unit into passive mode. The invention further relates to a detection system comprising a multitude of detection units as described and to a method for controlling a detection unit.

Abstract: The present invention relates to an aqueous dispersion based on a polymer and a crosslinker, a method for applying a coating to a substrate, and a substrate provided with such a coating. One aspect of the present invention is to provide a formulation for an aqueous dispersion that can be used to obtain a coating that will not turn yellow and is resistant to hydrolysis.

Abstract: A method for producing optical rod-shaped graded-index polymer preform by making the composition of the preform near the core differ from the composition of the shell of the preform by polymerization with rotation of a mixture containing the starting substances, whereby a mixture comprising various monomers is rotated and that after achieving a distribution of the monomers, the polymerization is carried out with rotation of the mixture, or that a monomer and thermoplastic polymer-containing mixture, whereby said monomer is different from the monomer from which said polymer has been prepared, is rotated and that, after achieving a distribution of said monomer and polymer, the monomer present in said mixture is subsequently polymerized with rotation, in which both cases the rotation is carried out with a diameter dependent rotation velocity, represented by the following general equation: rpm>10,000 d.sup.-0.5 wherein: rpm=rotation velocity, revolutions per minute d=diameter of the preform (cm).