Adiabatic calorimeter as an ultra-low frequency spectrometer
High themdl stability and temperature resolution of the adiabatic calorimetry mke it possible to study freezing process of disorder existing in coladensed mtters. liquids around their glass transition regions. It turned out that the enthalpy relaxatim phenanenon occurreed also in crystalline materials associated with the freezing of relevant degree of freedam Since the measurement is based on the time evolution of enthalpy through the observation of temperature change under adiabatic condition, the adiabatic calorimetry belongs to time-danain spectroscopy corresponding to the frequency range between 10 mHz and 1 pHz. applicability to a wide range of substances indepndently of the chenical nature and physical state. occurring in several crystals are reviewed here with their implications. This was first demonstrated for
This paper considers a transient heat conduction problem for an infinite medium with two non-overlapping circular cavities. Suddenly applied, steady Dirichlet type boundary conditions are assumed. The approach is based on superposition and the use of the general solution to the problem of a single cavity. Application of the Laplace transform results in a semi-analytical solution for the temperature in the form of a truncated Fourier series. The large-time asymptotic formulae for the solution are obtained by using the analytical solution in the Laplace domain. The method can be extended to problems with multiple cavities and inhomogeneities.