Nanofluids are used to improve the thermal conductivity of heat transfer fluids. This study examined the effects on thermal conductivity of zinc oxide (ZnO)/ethylene glycol + water nanofluids as increasing concentrations of ZnO nanopartilces were added to the solution. A Thermal Constants Analyzer (TPS) measured the thermal conductivity of the nanofluids using the Transient Plane Source (TPS) method. As expected, the thermal conductivities of the solutions increased with nanoparticle concentration, ...