A method for optimizing an ore beneficiation flotation process through which a comminuted ore slurry, which includes a sulphide mineral, passes to produce a final flotation concentrate and a final flotation tail. Antenna elements, which are adapted to receive electromagnetic radiation in a desired portion of the THz region, are electrically coupled the p-channel injector electrodes of the heterojunction thyristor device such the that antenna elements are electrically connected to the p-type modulation doped quantum well interface of the device. This molecule has been named GDNF receptor since it is the first known component of a receptor system. The polymer foam core is preferably an exothermic foam such as polyurethane, and heat generated by the exothermic foam cures the epoxy, thereby causing the fibrous layer to adhere to the foam core. During an emergency operation that is caused by large movements occurring within the vicinity of the expansion joint gap, one or more mechanically fused elements may break away to improve system predictability, or to limit damage to the expansion joint system, the surrounding underlying structural members, or both. The invention can also be described as a method of detecting the presence of an analyte in a fluid using the apparatus and cartridge.