  Medium effects on charged-particle production are studied using three
analysis techniques. We find angular collinearity and number correlations on
$p_t$ at moderate $p_t<3$ GeV/$c$. In this $p_t$ range abundant multiplicities
enable precision measurements of correlations of non-identified hadrons for
kinematic variables ($p_t$,$\eta$,$\phi$). Methods include (1) direct
construction of two-particle correlation functions, (2) inversion of the
bin-size dependence of non-statistical multiplicity fluctuations and (3)
two-dimensional discrete wavelet analysis. Two-particle correlations on $p_t$
exceed expectations from a model of equilibrated events with fluctuating global
temperature. A correlation excess at higher $p_t$ is interpreted as final-state
remnants of initial-state semi-hard collisions. Lower-$p_t$ correlations
exhibit a saddle structure varying with centrality. Variations in the forms and
strengths of low and high $p_t$ correlations with centrality suggest transport
of semi-hard collision products into the lower $p_t$ region as a manifestation
of in-medium dissipation of minijets. Correlations on $p_t$ can be associated
with angular correlations on ($\eta$,$\phi$), using analysis methods (1), (2)
or (3). In particular, wavelet analysis (3) is performed in the ($\eta$,$\phi$)
space in bins of $p_t$ ($<2$ GeV/$c$). Observed angular correlation structures
include those attributed to quantum correlations and elliptic flow, as well as
a localized structure, increasing in amplitude with $p_t$, and presumed to
originate with minijets. That structure evolves with increasing centrality in a
way which also suggests dissipation, including an increased correlation length
on $\eta$ which may be related to the influence of a longitudinally expanding
medium on minijet fragmentation.
