The invention relates to a method of treating water with activated sludge containing micro-organisms. An empty switch is disposed within the secondary fuel tank and generates a second signal. Examples are described in which the resonant near-fields of a large-area replica molded photonic crystal efficiently couples light from a laser to dielectric-metal \u201cpost-cap\u201d nanostructures deposited on the photonic crystal surface by a glancing angle evaporation technique, achieving a high SERS enhancement factor. In one form, the customized deflection model helps to obtain a compact, linear, and flexible analytical model with non-iterative solution, multiple continuous elastic foundations, third-order displacement fields, simple stress-field determination, and capability to compute dynamic deflection characteristics.