A preformed hanger rod stiffening clip that improves the strength and stability of hanger rods to withstand compression forces. A 2-pattern photonic crystal has a large, complete photonic band gap. The ventilator processes a respiratory airflow signal, a respiratory effort signal and their respective rates of change to determine a phase using standard fuzzy logic methods. The pivoting unit is located between the first socket and the second socket. The carbon which would pollute the catalyst is eliminated by means of a catalyst regeneration phase with steam, which generates a reaction gas that can be re-used as a source of energy . The interface circuitry is selected to interface with the selected switch size according to the desired voltage and current range.