  Unusual scattering effects from tiny spherical particles may be obtained when
concentric shells are designed by pairing together 'complementary'
double-negative (DNG), single-negative (SNG), and/or standard double-positive
(DPS) materials. By embedding these highly polarizable scatterers in a host
medium one can achieve a bulk medium with interesting effective parameters.
Some physical insights and justifications for the anomalous polarizability of
these concentric spherical nano-particles and the effective parameters of the
bulk composite medium are discussed.
