  We discuss the temperature-dependent thermoelectric transport properties of
semiconductor nanostructures comprising a quantum dot coupled to quantum wires:
the thermal dependence of the electrical conductance, thermal conductance, and
thermopower. We explore the universality of the thermoelectric properties in
the temperature range associated with the Kondo crossover. In this thermal
range, general arguments indicate that any equilibrium property's temperature
dependence should be a universal function of the ratio $T^{*}=T/T_{K}$, where
$T_{K}$ is the Kondo temperature. Considering the particle-hole symmetric,
spin-degenerate Anderson model, the zero-bias electrical conductance has
already been shown to map linearly onto a universal conductance through a
quantum dot embedded or side-coupled to a quantum wire. Employing rigorous
renormalization-group arguments, we calculate universal thermoelectric
transport coefficients that allow us to extend this result to the thermopower
and the thermal conductance. We present numerical renormalization-group results
to illustrate the physics in our findings. Applying the universal
thermoelectric coefficients to recent experimental results of the electrical
conductance and thermo-voltages versus $V_{gate}$, at different temperatures in
the Kondo regime, we calculate all the thermoelectric properties and obtain
simple analytical fitting functions that can be used to predict the
experimental results of these properties. However, we cannot check all of them,
due to the lack of available experimental results over a broad temperature
range.
