Mon premier blog

Diffusion in Solids Paul Shewmon
Publisher: Wiley

Copper and nickel powder sintering is essentially the interface diffusion and migration process. Imperfections: role of surface defect on crack propagation etc – Mode of plastic deformation: mechanism of slip & twinning, dislocation climb & cross slip, dislocation sources, frank-read source – Diffusion in solids, fick's laws, applications. We see that the reaction rates strongly constraint the depth of the column affected by the CO2 diffusion. Diffusion is obvious in gases and liquids, but diffusion in solids rather than of solids is more likely. Solids do not flow and do not have a defined shape. Finally the amount of CO2 trapped as solid carbonate (siderite) was compared for the base case and reduced reactive surface area (d). Once sorbed, energy input forces bulk or surface diffusion into or out of a porous solid--a process also driven by a concentration gradient. Solids expand when heated and contract when cooled. Diffusion is a slow process and is not dependent on a 'living system'. This project will be performed at the NMR centers at the Universities of Aveiro (solids NMR) and Nova de Lisboa (liquids NMR).