Accurate solutions to the equations governing the natural convection of air in a cubic cavity, thermally driven on two vertically opposite faces, are given for Rayleigh number values up to 10 7. These solutions are obtained with a pseudo-spectral Chebyshev algorithm based on the projection-diffusion method with a spatial resolution supplied by polynomial expansions, which go up to 111times111times111. The solutions are believed to be accurate-better than (0.03, 0.05)% in relative global error for the corresponding Rayleigh number (Ra) range (10 3, 10 7). This clearly indicates a non-monotonic evolution of the flow structure as Ra increases

Abstract Scaffolds are three-dimensional substrates that allow cell differentiation, proliferation and growth. In order to achieve properties such as biocompatibility, adequate porosity and interconnectivity, ideal rates of degradation and mechanical properties, the main objective of this study was the production of =CE=B2-tricalcium phosphate (=CE=B2-TCP) scaffolds by freeze casting method. Through the variation of the solids content, it was possible to evaluate its influence on the microstructure and the physical and mechanical properties of the =CE=B2-TCP scaffolds. The porosity varied between 85 and 55% for solids contents of 10 and 30 vol%, respectively. The pore morphology was characterized by a lamellar pattern, similar to ice crystals. By increasing solid content in the ceramic suspension, it was possible to observe a reduction of the number of lamellar pores. Mechanical compressive strength values ranged from 0.10 to 0.71 MPa. The scaffolds that presented the highest compressive strength value were characterized by degradation test. The results revealed that the weight loss increased with the immersion time. The highest value of the weight loss was 2.9=C2=B10.64% for the period of 28 days. The =CE=B2-TCP scaffolds show great potential to use in tissue engineering.=09