  It is well-known that the non-supersymmetric D3 brane (a cousin of BPS D3
brane) including its black version of type IIB string theory has a decoupling
limit, where the decoupled geometry is the gravity dual of a
non-supersymmetric, non-conformal (finite temperature) quantum field theory
having some properties similar to QCD. Using the ideas of AdS/CFT we study some
non-perturbative aspects of this quantum field theory. Since in this case we
have a Yang-Mills theory (no quarks) with running coupling (non-constant
dilaton), we compute the gluon condensate in this theory as a function of
temperature and also compute the beta function. The behavior of the gluon
condensate is found to resemble much like the SU(3) lattice QCD result and the
beta function is found to be negative. We further compute both the pseudoscalar
and the scalar glueball mass spectra in this theory using WKB approximation and
find that the mass ratios of the first excited state to the ground state of the
scalar glueball are quite close to the lattice QCD results.
