Many oxides tend to form different structures (polymorphs) for small particles. High temperature oxide melt solution calorimetry has been used to measure the enthalpy as a function of polymorphism and surface area for oxides of Al, Ti, and Zr. The results confirm crossovers in polymorph stability at the nanoscale. The energies of internal and external surfaces of zeolitic silicas with open fram...

For the binary liquid systems formic acid + acetic acid, formic acid + propionic acid, and acetic acid + propionic acid, we give the results of new calorimetric measurements of the molar excess enthalpy H at 25 °C, 30 °C, 40 °C, and 60°C, covering the entire range of compositions. H is always positive, increases linearly with the temperature, and is slightly asymmetric with respect to the mole ...

Abstract In the present work, a numerical investigation of Latent Heat Thermal Energy Storage system (LHTESs) is performed on vertical shell and tube geometry, made porous medium filled with phase change material (PCM). The LHTESs cylinder corrugated inner surface at constant temperature above PCM melting temperature; external there are heat losses to outside top bottom surfaces adiabatic. used...

An evident inequality between the enthalpy of crystallization of amorphous selenium, DHx , and the enthalpy difference between the undercooled liquid and the conventional polycrystalline selenium, DHl→c, was observed, which is inconsistent with the widely accepted idea that the two enthalpies should be equal. The inequality between the two enthalpies is attributed to the excess enthalpy of the ...