A detector bar, a detector formed from a number of detector bars, and a computed-tomography unit including such a detector is disclosed, each detector bar being formed from a number of individual modules. A first drive mechanism is provided to rotate an assembly of the plates so that a selected column of conveyors is in alignment with the receiving area and, for each plate, a second drive mechanism is provided to operate the conveyor that is in the transferring orientation so that an article, or prize, on the conveyor is transferred to the receiving area. Such an index may be implemented as a bitmap index. 01 to 3 parts of a cross-linking agent per 100 parts the weight sum of all monomers; and wherein the polymerization reaction product is substantially free of solvent.