A dual band antenna assembly includes a radiating metal strip fabricated on a baseboard. Other aspects of the invention are directed to the use of these compounds to decrease excess sebum secretions and to stimulate hair growth. The iron oxide-based nanoparticles encapsulated in the composite interact with each other to produce a synergistic effect on the amplification of magnetic resonance signals, and thus have an relatively excellent contrast effect compared to when they exist as single particles. The silicon plug has a top portion that is heavily doped with a first type dopant and a bottom portion that is lightly doped with a second type dopant.