scholarly journals Prediction of phase equilibria in water-salt systems

2020 ◽  
Vol 61 (3) ◽  
pp. 86-91
Author(s):  
Evgeny S. Mironovich ◽  
◽  
Alexander V. Kolyado ◽  
Ivan K. Garkushin ◽  
Evgeny A. Kleymenov ◽  
...  
Keyword(s):  
Melting Point ◽  
Phase Equilibria ◽  
Calculated Data ◽  
Hydrogen Phosphate ◽  
Calculation Algorithm ◽  
Eutectic Melting ◽  
Average Deviation ◽  
Potassium Hydrogen ◽  
Water Salt ◽  
Salt Systems

Produced review scientific and technical reference books on individual substances and the two-component systems forming part of the water-salt system K2HPO4 – (NH2)2CO – H2O. To predict phase equilibria in a real system, a mathematical model is proposed that allows one to determine the dependence of the activity coefficient of a substance or ion on the concentration and temperature of the solution. The solution of the system of equations was carried out in the environment of the table processor Microsoft Excel as a result, in terms of potassium hydrogen phosphate, the following characteristics of the eutectic alloy with the calculated content of components in the eutectic were obtained: 36.5 % wt. K2HPO4, 11.5 % wt. (NH2)2CO, 52.0 % wt. H2O, melting point 250.6 K (-22.6 C). In order to search for a composition with a minimum crystallization temperature in the ternary urea – potassium hydrogen phosphate – water system, the simplex K2 HPO46H2O – (NH2)2 was studied CO – H2O by visual polythermal method. The eutectic in the studied system crystallizes at a temperature of minus 28 С and contains 8 % wt. carbamide, 35 % wt. potassium hydrogen phosphate, 57 % wt. water. An analysis of the data obtained by experimental and computational methods showed satisfactory convergence. The average deviation of the calculated data from the experimental ones was 18.9% in composition and 2.3% in terms of the eutectic melting point. The proposed calculation algorithm can be used to predict the characteristics of eutectics in ternary water - salt systems for planning the experiment.

Phase equilibria in water–salt systems from sodium, magnesium, and calcium nitrates and deicing properties of nitrate compositions

2017 ◽  
Vol 51 (4) ◽  
pp. 523-526 ◽  
Author(s):  
E. A. Frolova ◽  
D. F. Kondakov ◽  
L. I. Avdyushkina ◽  
A. V. Bykov ◽  
A. N. Shkarupin ◽  
...  
Keyword(s):  
Phase Equilibria ◽  
Sodium Magnesium ◽  
Water Salt ◽  
Salt Systems

Investigation of Phase Equilibria in Quinary Water–Salt Systems

2018 ◽  
Vol 63 (3) ◽  
pp. 598-612 ◽  
Author(s):  
Sherali Tursunbadalov ◽  
Lutfullo Soliev
Keyword(s):  
Phase Equilibria ◽  
Water Salt ◽  
Salt Systems

Phase Equilibria in Water-Salt Systems Consisting of Potassium, Sodium, and Ammonium Carbonates and Anti-Icing Properties of Carbonate Compositions

2018 ◽  
Vol 52 (4) ◽  
pp. 587-590
Author(s):  
E. A. Frolova ◽  
D. F. Kondakov ◽  
L. I. Avdyushkina ◽  
A. V. Bykov ◽  
A. N. Shkarupin ◽  
...  
Keyword(s):  
Phase Equilibria ◽  
Potassium Sodium ◽  
Water Salt ◽  
Salt Systems

Phase Equilibria in Multicomponent Water–Salt Systems

2016 ◽  
Vol 61 (7) ◽  
pp. 2209-2220 ◽  
Author(s):  
Sherali Tursunbadalov ◽  
Lutfullo Soliev
Keyword(s):  
Phase Equilibria ◽  
Water Salt ◽  
Salt Systems

Melting and Crystallization of Poly(oxyethylene) Mixtures

1995 ◽  
Vol 60 (11) ◽  
pp. 1855-1868 ◽  
Author(s):  
Ivo Lapeš ◽  
Josef Baldrian ◽  
Ján Biroš ◽  
Julius Pouchlý ◽  
Hanes Mio
Keyword(s):  
Melting Point ◽  
Lamellar Structure ◽  
Composition Dependence ◽  
Eutectic Phase ◽  
Eutectic Melting ◽  
Pure Polymer ◽  
X Ray ◽  
Long Period ◽  
Solid Liquid ◽  
Melting And Crystallization

Solid-liquid eutectic phase diagrams of mixtures of poly(oxyethylene) (M.w. 2 000) with hydroxy and methoxy endgroups, crystallizing in extended-chain macroconformation only, with glutaric acid, benzoic acid or 1,2-diphenylethane are given. The composition dependence of the melting temperature can be fitted by the Flory-Huggins equation. Interaction parameters X and interaction energy densities B evaluated from the diluent branch of the phase diagram are consistent with those obtained from the polymer branch provided the calorimetric value of enthalpy of polymer fusion is used in the latter computation. Measurements of small- and wide-angle X-ray scatterings showed a stacked lamellar structure of POE. Below the eutectic melting point, the long period of the polymer is almost independent of the diluent concentration. On raising temperature gradually from this melting point to the melting point of pure polymer, the increasing long period indicates the penetration of the diluent between the lamellae. As follows from SAXS measurements, the crystallinity of poly(oxyethylene) in the mixtures remains unchanged compared to that of the pure polymer.

Study on Optimization of Fermentation Condition for Nitrilase-Producer Escherichia Coli BL21 (DE3)/pET-Nit

2011 ◽  
Vol 175-176 ◽  
pp. 192-196 ◽  
Author(s):  
Li Li Feng ◽  
Jian Fei Zhang ◽  
Hui Luo ◽  
Zheng Li ◽  
Hong Jie Zhang
Keyword(s):  
Escherichia Coli ◽  
Recombinant Strain ◽  
Culture Medium ◽  
Culture Conditions ◽  
Fermentation Condition ◽  
Hydrogen Phosphate ◽  
Strain Bl21 ◽  
Initial Ph ◽  
Potassium Hydrogen ◽  
Optimization Of Fermentation

The paper concentrated on the optimization of the recombinant strain BL21 (DE3)-PE7-Nit. The component of culture medium and the culture conditions were optimized. The optimized medium was: yeast extract 10 g/l, L-glutamate sodium 8 g/l, MgSO4.7H2O 0.7 g/l, Isopropyl-β-D-thiogalactopyranoside 0.3 mmol/L, potassium hydrogen phosphate 0.5 g / L, phosphate Potassium 0.5 g / L and the culture condition was: initial pH 7.0, inoculum 2%. The result showed that the activity of nitrilase prepared with these conditions increased by 130.37 % through optimization.

Sign in / Sign up

Export Citation Format

Share Document