Thermodynamics,
Gabriela Lisa; Iuliana Bîrgăuanu; Catalin Lisa; Alexandra Bargan; Silvia Curteanu
Abstract
This paper evaluates the following properties: surface tension and refractive index in an area of composition influenced by component miscibility, four temperatures: 293.15, 303.15, 313.15 and 323.15 K and atmospheric pressure (0.1 MPa), for binary and ternary systems of benzyl alcohol, n-hexanol and ...
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This paper evaluates the following properties: surface tension and refractive index in an area of composition influenced by component miscibility, four temperatures: 293.15, 303.15, 313.15 and 323.15 K and atmospheric pressure (0.1 MPa), for binary and ternary systems of benzyl alcohol, n-hexanol and water, less studied in the literature. There was an increase in surface tension with increasing temperature for the n-hexanol-water binary system and the ternary system. Given that the refractive index is determined much easier and with a lower consumption of substances than the surface tension, in this paper the statistical processing of experimental data with multiple linear regression method (MLR) was applied and the following model was obtained: exc= 478.5+101.514⸱X1+58.389⸱X2+ 47.083⸱(T/273.15)-416.897⸱n. It correlates the excess surface tension (exc) with the composition (X1 and X2), the normalized temperature and the refractive index (n). Modelling with neural networks was also performed. The multilayer perceptrons (MLP) neuronal model (4:20:12:1) performs better than the MLR model, but the advantage of the latter is that it provides a mathematical expression that can be easily used by chemical engineers to predict excess surface tension based on experimental measurements of refractive index.
Modeling and Simulation
mohsen pirdashti; kamyar movagharnejad; silvia Curteanu; Florin Leon; Farshad Rahimpour
Volume 13, Issue 4 , November 2016, , Pages 14-32
Abstract
Guanidine hydrochloride has been widely used in the initial recovery steps of active protein from the inclusion bodies in aqueous two-phase system (ATPS). The knowledge of the guanidine hydrochloride effects on the liquid-liquid equilibrium (LLE) phase diagram behavior is still inadequate and no comprehensive ...
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Guanidine hydrochloride has been widely used in the initial recovery steps of active protein from the inclusion bodies in aqueous two-phase system (ATPS). The knowledge of the guanidine hydrochloride effects on the liquid-liquid equilibrium (LLE) phase diagram behavior is still inadequate and no comprehensive theory exists for the prediction of the experimental trends. Therefore the effect the guanidine hydrochloride on the phase behavior of PEG4000+ potassium phosphate+ water system at different guanidine hydrochloride concentrations and pH was investigated in this study. To fill the theoretical gaps, the typical of support vector machines was applied to the k-nearest neighbor method in order to develop a regression model to predict the LLE equilibrium of guanidine hydrochloride in the above mentioned system. Its advantage is its simplicity and good performance, with the disadvantage of an increase the execution time. The results of our method are quite promising: they were clearly better than those obtained by well-established methods such as Support Vector Machines, k-Nearest Neighbour and Random Forest. It is shown that the obtained results are more adequate than those provided by other common machine learning algorithms.