The main objective of the work is to develop numerical method for improving design/simulation tools and answering to specific questions related with heat and mass transfer inside a pressurized volumetric receiver (PVR), providing fundamental basis to design new receivers for the DAHAN project...

Surface phase diagrams of a semi-infinite simple cubic spin 12 Ising system in a random surface field are investigated by the use of effective-field theory with correlations. Surface tricritical behavior is found, when the enhanced surface exchange interaction takes a large value.