a two-dimensional model of al, si ordering in alkali feldspar is formulated and used to calcul~tea ccurately the configurational entropy for the model. for this purpose, a new method called independent basic unit or ibu is introduced. to compare the results with the exact values, this method is applied to the onedimensional model of albite. the results given by ibu are found to be accurate to t...

A two-dimensional single particle finite element model was used to examine the effects of particle fragmental pattern on the average molecular weights, polymerization rate and particle overheating in heterogeneous Ziegler-Natta olefin polymerization. A two-site catalyst kinetic mechanism was employed together with a dynamic two-dimensional molecular species in diffusion-reaction equation. The i...

in an open bounded domain Ω ⊂ R2, where u(t, x) > 0, ω(t, x) ∈ R2 and E denote the population density, the average velocity of dispersing individuals, and the individual net reproduction rate, respectively. In this model, the individuals are assumed to disperse randomly in space (δ ∆u) with a bias −∇ · (u ω) in the direction of increasing reproduction rate, the term ε ∆ω acting as a mollifier t...

in this research a three dimensional model is explained which simulate the oil spill behavior inseas. this model is the developed version of previous two-dimensional study of aghajanloo et al., 2013.because of three-dimensional nature of the oil dispersion/movement in water, this is a more realistic model of oil spill transport and fate in marine environment. the model is based on eulerian appr...