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Applying Gradient theory to calculate nucleation rates and compare with data. Nora Al-Zubi Dr. Abdalla Obeidat Department of Physics JUST
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Outline Metastability and nucleation Temperature dependence of classical theories DFT and the road to GT (why GT?) Applications to GT Conclusions
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The binodal curve (solid dome)separates one-phase and two-phase states T C = critical temperature The spinodal curve (dashed dome) separates metastable and unstable states One true horizontal isotherm is shown Adapted from Davis (1996) gas liquid fluid critical point binodal spinodal Metastable and unstable regions for the van der Waals fluid
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Classical nucleation rates are too low at low T; too high at high T.
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Chain of Rotators Equation of state for Ethanol and Methanol
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DFT and the road to GT
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Density Gradient theory
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The ingredients for GT
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GT Why? DFT Adv. –S–S–S–Statistical Mechanical approach disAdv. –D–D–D–Depends on intermolecular potential GT disAdv. –A–Approximation to DFT Adv. –S–Semi form of DFT –D–Depends on EOS
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Applications to GT using JA and CPHB Density profiles Thicknesses Number of molecules Radius of droplets Work formation Nucleation rates
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Density Profiles
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Nucleation rates of H2O based on CPHB
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Conclusions Gradient theory is promising theory to improve the temperature dependence of nucleation rates.
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Thank You
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