Building and Breaking Bonds by Homogenous Nucleation in Glass-Forming Melts Leading to Transitions in Three Liquid States

The thermal history of melts leads to three liquid states above the melting temperatures Tm containing clusters—bound colloids with two opposite values of enthalpy +Δεlg × ΔHm and −Δεlg × ΔHm and zero. All colloid bonds disconnect at Tn+ > Tm and give rise in congruent materials, through a first-order transition at TLL = Tn+, forming a homogeneous liquid, containing tiny superatoms, built by short-range order. In non-congruent materials, (Tn+) and (TLL) are separated, Tn+ being the temperature of a second order and TLL the temperature of a first-order phase transition. (Tn+) and (TLL) are predicted from the knowledge of solidus and liquidus temperatures using non-classical homogenous nucleation. The first-order transition at TLL gives rise by cooling to a new liquid state containing colloids. Each colloid is a superatom, melted by homogeneous disintegration of nuclei instead of surface melting, and with a Gibbs free energy equal to that of a liquid droplet containing the same magic atom number. Internal and external bond number of colloids increases at Tn+ or from Tn+ to Tg. These liquid enthalpies reveal the natural presence of colloid–colloid bonding and antibonding in glass-forming melts. The Mpemba effect and its inverse exist in all melts and is due to the presence of these three liquid states.

H₂SO₄–H₂O binary and H₂SO₄–H₂O–NH₃ ternary homogeneous and ion-mediated nucleation: lookup tables version 1.0 for 3-D modeling application

Formation of new particles in the atmosphere has important implications for air quality and climate. Recently, we have developed a kinetically based H2SO4–H2O–NH3-ion nucleation model which well captures the absolute values of nucleation rates as well as dependencies of nucleation rates on NH3 and H2SO4 concentrations, ionization rates, temperature, and relative humidity observed in the well-controlled Cosmics Leaving Outdoor Droplets (CLOUD) measurements. Here we employ the aforementioned recently developed kinetic nucleation model to generate nucleation rate lookup tables for H2SO4–H2O binary homogenous nucleation (BHN), H2SO4–H2O–NH3 ternary homogeneous nucleation (THN), H2SO4–H2O-ion binary ion-mediated nucleation (BIMN), and H2SO4–H2O–NH3-ion ternary ion-mediated nucleation (TIMN). A comparison of nucleation rates calculated using the lookup tables with CLOUD measurements of BHN, BIMN, THN, and TIMN is presented. The lookup tables cover a wide range of key parameters controlling binary, ternary, and ion-mediated nucleation in the Earth's atmosphere and are a cost-efficient solution for multidimensional modeling. The lookup tables and FORTRAN codes, made available through this work, can be readily used in 3-D modeling. The lookup tables can also be used by experimentalists involved in laboratory and field measurements for a quick assessment of nucleation involving H2SO4, H2O, NH3, and ions.

H₂SO₄-H₂O binary and H₂SO₄-H₂O-NH₃ ternary homogeneous and ion-mediated nucleation: Lookup tables for 3-D modeling application

Formation of new particles in the atmosphere have important implications for air quality and climate. Recently, we have developed a kinetically-based H2SO4-H2O-NH3-Ions nucleation model which captures well the absolute values of nucleation rates as well as dependencies of nucleation rates on NH3 and H2SO4 concentrations, ionization rates, temperature, and relative humidity observed in the well-controlled Cosmics Leaving OUtdoor Droplets (CLOUD) measurements. Here we employ the aforementioned recently developed kinetic nucleation model to generate nucleation rate look-up tables for H2SO4-H2O binary homogenous nucleation (BHN), H2SO4-H2O-NH3 ternary homogeneous nucleation (THN), H2SO4-H2O-Ions binary ion-mediated nucleation (BIMN), and H2SO4-H2O-NH3-Ions ternary ion-mediated nucleation (TIMN). A comparison of nucleation rates calculated using the lookup tables with CLOUD measurements of BHN, BIMN, THN, and TIMN is presented. The lookup tables cover a wide range of key parameters controlling binary, ternary and ion-mediated nucleation in the Earth’s atmosphere, and are a cost-efficient solution for multi-dimensional modeling. The lookup tables and FORTRAN codes, made available through this work, can be readily used for BHN, THN, BIMN, and TIMN simulations in 3-D modeling. The lookup tables can also be used by experimentalists involved in laboratory and field measurements for a quick assessment of nucleation involving H2SO4, H2O, NH3, and Ions.

Computational fluid dynamics simulation of the supersonic steam ejector using different condensation model

This paper addresses the non-equilibrium condensation (NEC) in supersonic steam ejector under the assumptions of no slip velocity between the droplets and vapor phase and homogenous nucleation. The experimental data carried out by Moore has been used to verify the numerical results. It is illustrated that the maximum value of the flow mach number of the NEC model is lower than that of the equilibrium condensation model, and NEC model increases the ejector?s entrainment ratio in comparison equilibrium condesation model. When using the NEC model, the nucleation characteristics such as subcooling degree, nucleation rate could be obtained in ejector flow field.