Abstract: Apparatus and process for marking a surface with a highly visible and substantive mark comprising mixing a dry granular, free-flowing superabsorbent polymer powder with liquid, preferably water, and dye to form a semi-solid gel and depositing the gel onto the surface to be marked. The marking apparatus comprises a chamber for mixing the gel and a ram used to eject the gel from the chamber without excess mechanical agitation and without causing significant breakdown of the gel. The dye makes the gel very visible, the bulk of the gel makes it more easily visible, the nature of the gel makes it temporary; easily dispersed with time, sunlight or water.

Abstract: A multisensor vehicle-mounted mine detector having one or more sensors leading the vehicle for detecting objects in the ground while moving. A navigational system tracks the coordinates of the detected objects, performs data fusion, declares whether the object is a target worthy of interest and if so, stops the vehicle with a trailing thermal neutron activator sensor (TNA) over the coordinates of the object and interrogating the object with slow neutrons to confirm whether it contains sufficient nitrogen to indeed be a mine. The TNA confirmation is kept brief due to the use of a strong source coupled with means for analysing the resultant pulses and rejecting piled-up pulses. The difference between an integration of the entire pulse and a portion of the pulse is compared against a predetermined difference for a normal pulse wherein variations therebetween are indicative of a piled-up pulse which is then rejected.