A system and method is disclosed for detecting andor mitigating an overload condition from one or more first computers, such as a distributed denial of service attack, viral attack, or the like, targeting one or more of a plurality of second computers located on a network. In one embodiment a phase detector provides phase information for low to high data signal transitions only. The invention may be implemented in a cockpit display, a flight simulator, a graphical flight planning application, or in any other application having a graphical user interface. To collect particulate matter from the fluid suspension, the instruments can cause a fluid flow that pulls fluid across the filter to trap particulate matter against one surface of the filter. This allows realization of a particularly effective tunable filter circuit with only four inductive resistors. Fluid, such as corrosion inhibitors, can be circulated in a closed loop which includes the annulus of the riser terminating at a platform or floating vessel, a fluid storage tank located on the platform or vessel and an umbilical tube terminating at the platform or vessel and at a subsea location.