Vanadium compounds as anti-proliferative agents. An intermediate inspection is performed about presenceabsence of any defect in the clad metal using the control surface. , and the plasticizer is an aromatic benzenesulphonamide represented by the general formula . This circuit uses the failure of a portion of the circuit which generates at least one input control signal, so as to change the overall circuit characteristics as the circuit ages. In one embodiment, a drill leg is coated and then exposed to a carbon-rich environment at an elevated temperature. Identical symmetrical secondary circuits on the transformers have a rectifier stage electrically connected to an inductor in series with an upper capacitor to form an upper low pass filter, and a high speed semiconductor switch coupled to a node between the inductor and rectifier stage provides a return path to ground.