  We show that the effect of size dependence of the melting temperature of
nanocrystals may be used to govern anomalies of thermodynamic properties of
nanocrystals in the premelting range. For example, if temperature of
nanocrystals is near the melting point, their mechanical contact should result
in a change of the temperature and release of some heat. We discuss fundamental
possibility of construction of a "heat pump" to extract thermal energy from a
low-temperature medium.
