Before revision: α = ΔSf/k(η/v) According to Martin Glicksman in his book Principles of Solidification: An Introduction to Modern Casting and Crystal Growth Concepts (2011): α = ΔSf/Rg(η1/Z) where Rg is the universal gas constant.
After revision: α = ΔSf/k(η/v) According to Martin Glicksman in his book Principles of Solidification: An Introduction to Modern Casting and Crystal Growth Concepts (2011): α = ΔSf/(η1/Z) where Rg is the universal gas constant.