The presence of porosity not completely filled by water suggests that the liquid may be squeezed out from the inter-particle region to the unfilled pores as a result of the external applied pressure. However, Liquid Phase Sintering (LPS) can only occur in the presence of an interparticle liquid film (such as the one sketched in Figure 10). Therefore, in this section the applicability of the traditional LPS models to UCS is discussed in the case of porosity not completely filled by water.