Sharif Digital Repository

Governing equilibrium equations of thick-walled spherical vessels made of material following linear strain hardening and subjected to a steady-state radial temperature gradient using elasto-plastic analysis are derived. By considering a maximum plastic radius and using the concept of thermal autofrettage for the strengthening mechanism, the optimum wall thickness of the vessel for a given temperature gradient across the wall thickness is obtained. Finally, in the case of thermal loading on a vessel, the effect of convective heat transfer on the optimum thickness is studied and a general formula for the optimum wall thickness and design graphs for several different cases are presented. © 2008... 

The effect of thickness of TiO2 coating on synergistic photocatalytic activity of TiO2 (anatase)/α-Fe 2O3/glass thin films as photocatalysts for degradation of Escherichia coli bacteria in a low-concentration H2O2 solution and under visible light irradiation was investigated. Nanograined α-Fe2O3 films with optical band-gap of 2.06 eV were fabricated by post-annealing of thermal evaporated iron oxide thin films at 400 °C in air. Increase in thickness of the Fe2O3 thin film (here, up to 200 nm) resulted in a slight reduction of the optical band-gap energy and an increase in the photoinactivation of the bacteria. Sol-gel TiO2 coatings were deposited on the α-Fe2O 3 (200 nm)/glass films, and...