Dufour effect[¦dü·fȯr i′fekt]
the inverse phenomenon of thermal diffusion. If two chemically different nonreacting gases or liquids, which were initially at the same temperature, are allowed to diffuse into each other, then there arises a difference of temperatures in the system. In gases this difference can reach several degrees (for example, for nitrogen with hydrogen), while in liquids it measures approximately 103°C. The difference in temperatures is retained if a concentration gradient is maintained. The effect was first observed by the Swiss physicist L. Dufour in 1873.