The invention concerns a system comprising at least two panels, particularly floor panels for forming a covering. The invention enables the preparation of stable suspo-emulsions containing a variety of active ingredients and components and containing large quantities of oily components. Each sensor includes a resilient top portion having at least one resilient conductive member, and a resilient lower portion having active sections and resilient lower portion conductive members channeled and interconnected through the lower portion, the lower portion conductive members being separated by non-conductive material. For each DNA spot image: background and signal intensity levels are extracted from image characteristic values for the spot image, and difference values between the background intensity levels and signal intensity levels are determined. The nozzle needle of the injector is associated with a piston element which encourages the closing movement of the nozzle needle and counteracts its opening movement. The present invention further provides enantiomerically pure –tomoxetine –mandelate prepared from racemic tomoxetine.