Abstract: An electromagnetic tagging system is provided for remotely detecting and locating polymeric and other non-conductive structures situated behind barriers, such as underground plastic pipes or containers. The system comprises a fluctuating magnetic field source, a pattern of tags embedded in discrete regions of the wall of the polymeric structure, each tag including an amorphous magnetic metal target for generating a Barkhausen response when exposed to the fluctuating magnetic field source, and a portable detection circuit movable along the ground or other control surface for remotely detecting the Barkhausen response. The amorphous magnetic material in each tag is preferably in the form of a plurality of elongated particles having aspect ratios of at least 3 to 1 and arranged end-to-end.

Abstract: A process for removing paint by high pressure waterjet blasting of painted surfaces wherein the waterjet comprises a ferrofluid or other liquid containing tiny magnetic particles suspended therein. The particles may be in colloidal suspension or be suspended by agitation and are preferably polymer coated. The liquid-magnetic particle mixture lends itself to electromagnetic process control, run-off maintenance and waste processing capabilities. Thereby, the process can employ process control and waste remediation options.