A modelling system is provided in which a model generation computer stores within a model database a plurality of principle component analysis models for modelling individuals. The catalysts of the invention generally comprise nickel or a nickel-containing compound and at least one or more of titanium, tantalum, niobium, hafnium, tungsten, yttrium, zinc, zirconium, or aluminum, or a compound containing one or more of such element. The amount of particles is changeable to change the weight of the athletic shoe. In some embodiments, the controlled capacitance bridge connects segments of an input microstrip conductor.