Thermodynamic properties of the actinide oxides solid solutions: A calorimetric study

The work presented in this thesis provides new data on the behaviour of the binary mixed actinide oxides of the following systems: (Th,Pu)O2, (U,Pu)O2, (Th,U)O2, (U,Am)O2. The results were obtained by performing measurements in a large temperature interval, for some compounds the thermodynamic properties were studied in the range from about 2 to...

The role of temperature in nucleation processes

Heat and mass transfers are coupled processes, also in nucleation. In principle, a nucleating cluster would have a different temperature compared to the surrounding supersaturated old phase because of the heat release involved with attaching molecules to the cluster. In turn a difference in temperature across the cluster surface is a driving...

Transport of heat and mass in a two-phase mixture: From a continuous to a discontinuous description

We present a theory that describes the transport properties of the interfacial region with respect to heat and mass transfer. Postulating the local Gibbs relation for a continuous description inside the interfacial region, we derive the description of the Gibbs surface in terms of excess densities and fluxes along the surface. We introduce...

Ca(AlH4)2, CaAlH5, and CaH2+6LiBH4: Calculated dehydrogenation enthalpy, including zero point energy, and the structure of the phonon spectra

The dehydrogenation enthalpies of Ca(AlH4)2, CaAlH5, and CaH2+6LiBH4 have been calculated using density functional theory calculations at the generalized gradient approximation level. Harmonic phonon zero point energy (ZPE) corrections have been included using Parlinski’s direct method. The dehydrogenation of Ca(AlH4)2 is exothermic, indicating...

Thermal and electrical properties of porphyrin derivatives and their relevance for molecule interferometry

The authors present new measurements of thermal and electrical properties for two porphyrin derivatives. They determine their sublimation enthalpy from the temperature dependence of the effusive beam intensity. The authors study H2TPP and Fe(TPP)Cl in matter-wave interferometry. Both molecules have nearly equal de Broglie wavelengths but...