N. V. K. Dutt

Quantitative structure-property relationships for normal saturated and unsaturated fatty acids

Quantitative structure-property relationships, a technique of deriving properties of compounds from knowledge of their structures, has been applied to aliphatic carboxylic acids, an industrially important group of compounds. Equations have been developed from the molecular connectivity of the first order and the molar refraction as inputs which, on testing with data of seven properties, yielded average absolute deviations ranging between 0.9 and 6.7%. The compounds studied ranged between C1 and C30 for saturated and C3 to C22 for unsaturated fatty acids. The properties studied are normal melting and boiling points, critical temperature and pressure, and heats of fusion, combustion and formation.

Atomic and Structural Contributions to Molar Refraction and Extension to Mixtures

Abstract Molar refraction of pure liquids has been calculated for well over a thousand substances, from an evaluated set of atomic and structural contributions. On an overall basis, the calculated values are in agreement with the experimental data, showing an average absolute deviation of 0.6%, and an average of maximum deviations of 2.1%. The effect of temperature on molar refraction has also been studied and found to show an average absolute deviation of 0.8%. Molar refraction of binary liquid mixtures has been estimated from the molar refraction of pure liquids (calculated from atomic and structural contributions) and the mole fraction by applying the linear rule. The results for 25 randomly studied mixtures showed an average absolute deviation of 0.4%. The effect of estimating molar refraction of pure liquids (or liquid mixtures) as described above on the values of the various physico–chemical properties, calculated employing molar refraction (or its equivalent for polar substances – molar polarizatio...

Estimation of Solubility of Paraffins in Water by the Method of Neural Nets

Abstract Water solubilities of paraffins have been estimated by the method of artificial neural nets. The method, using the normal boiling point and temperature as the input parameters could estimate the solubilities of 151 paraffins at the temperatures of 298 K and 372 K with an overall deviation of 3.4%, yielding superior results over those obtained by least squares.

Estimation of coal conversion by supercritical solvents using the method of neural nets

Coal conversion by solvent extraction under supercritical conditions was estimated by the method of neural nets, using the experimental temperature (Te) and pressure (Pe), critical temperature (Tc) and critical pressure (Pc), volatile matter (VM) and atomic ratio of hydrogen to carbon (HC) of several coals as inputs. The method, representing the data on 15 solvents including water, with an average absolute deviation of 3.5%, could be used for obtaining reasonable estimates of coal conversion.

Determination of Hagenbach and Coutte Correction Factors for the Flow of Power Law Fluids

Abstract Hagenbach and Couette correction factors (KH and KC), constituents of the excess pressure drop resulting due to the flow of aqueous polymer solutions through a 2 : 1 pipe contraction have been determined. The data obtained in the present work, combined with those reported in the literature have been correlated in terms of the flow behaviour index(n) and the diameter contraction ratio β. While KH could be correlated in terms of n and β with reasonable accuracy, KC could be represented with an overall deviation of 18.9% over a data set of 14 points.

Property correlations for chlorofluoro carbons and alternatives using structural parameters

Because of their wide ranging applications, the properties of chlorofluoro carbons (CFCs) and their alternatives are studied and correlated in terms of the parameters derived from molecular structures. The properties correlated are of physical, thermodynamic and transport in nature. The input parameters include molar refraction (R M), molecular connectivity (χ) and van der Waals equation coefficients (a and b), all of which are easily estimated from molecular structures. The correlations developed for the 11 properties studied showed average absolute deviations ranging between 3.5% and 13.7%. The correlation coefficients calculated for the equations developed ranged between 0.9557 and 0.9921.

Isobaric Vapour Liquid Equilibrium Data for Binary Systems Phenol-Di-Isopropyl Ether and 2,4-Xylenol-Di-Isopropyl Ether

Abstract Motivated by chemical engineering design purposes, isobaric vapour liquid equilibrium data on two binary mixtures has been obtained. The temperature-mole fraction data were measured in a Swietoslawski ebulliometer.