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Faculty of Applied Sciences

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    Synthesis, characterization and thermophysical properties of ionic liquid N-methyl-N-(2′,3′-epoxypropyl)-2-oxopyrrolidinium chloride and its binary mixtures with water or ethanol at different temperatures
    (Elsevier, 2016) Vasanthakumar, Arumugam; Bahadur, Indra; Redhi, Gan G.; Gengan, Robert Moonsamy; Anand, Krishnan
    A novel ionic liquid, namely, N-methyl-N-(2′,3′-epoxypropyl)-2-oxopyrrolidiniumchloride [Epmpyr]+[Cl]− was synthesized and characterized by different techniques such as NMR (1H and 13C), FTIR, and elemental analysis. The water content of the ionic liquid was checked by Karl Fisher titration. Further, the density, ρ, and speed of sound, u, were measured for the above ionic liquid and the corresponding binary systems with water or ethanol at different temperatures ranging from (293.15 to 313.15) K. The derived thermodynamic properties for instance excess molar volumes, VE m isentropic compressibility, κs, and deviation in isentropic compressibility, Δκs, were investigated from the density and speed of sound data, respectively. It is noted that density and speed of sound of the ionic liquid and its binary mixtures were decreased with increase in temperature, whereas excess molar volume, isentropic compressibility, and deviation in isentropic compressibility values increased. Derived properties such as excess molar volumes, and deviation in isentropic compressibility data were fitted to the Redlich-Kister polynomial equation. The measured and calculated data were interpreted in terms of intermolecular interfaces and structural effects between similar and dissimilar molecules upon mixing.
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    Apparent molar volume and apparent molar isentropic compressibility for the binary systems {methyltrioctylammoniumbis(trifluoromethylsulfonyl)imide + ethyl acetate or ethanol} at different temperatures under atmospheric pressure
    (Elsevier, 2013-05-20) Bahadur, Indra; Deenadayalu, Nirmala
    The density (d) and speed of sound (u) for the binary systems were measured at 298.15, 303.15, 308.15, and 313.15 K under atmospheric pressure. The binary systems contained the ionic liquid (IL): methyltrioctylammoniumbis(trifluoromethylsulfonyl)imide ([MOA]+[Tf2N]−). The binary systems were ([MOA]+[Tf2N]− + ethyl acetate or ethanol). The apparent molar volume, Vφ, and the apparent molar isentropic compressibility, kφ, have been evaluated from the experimental density and speed of sound data, respectively. A Redlich–Mayer equation was fitted to the apparent molar volume and apparent molar isentropic compressibility data. The partial molar volume, View the MathML source, and partial molar isentropic compressibility, View the MathML source, of the binary mixtures have also been calculated at each temperature. The partial molar volume indicates that the intermolecular interactions for (IL + ethanol) are stronger than for (IL + ethyl acetate) at all temperatures and View the MathML source for both systems increases with an increase in temperature. The values of the infinite dilution apparent molar expansibility, View the MathML source, decreases with an increase in temperature. The isentropic compressibilities, ks, increases with an increase in temperature for both binary systems. Positive View the MathML source, for both binary systems can be attributed to the predominance of solvent intrinsic compressibility over the solute intrinsic effect.
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    Improvement of ethanol production from sugarcane molasses through enhanced nutrient supplementation using Saccharomyces cerevisiae
    (Academic Journals, 2012-03) Nofemele, Zuko; Shukla, Pratyoosh; Trussler, Arthur; Permaul, Kugen; Singh, Suren
    Saccharomyces cerevisiae as a yeast cream was utilized for alcoholic fermentation using sugar cane molasses. In the present study, fermentation was optimized for urea and yeast hydrolysate (YH) dosage and the combined effect was evaluated. Total sugars as inverts (TSAI) composition of molasses were -1 determined by HPLC as 39% (m/v). Urea concentrations of 4, 2 and 3 gl showed optimal ethanol -1 production at 30, 35 and 40°C respectively. A YH concentration of 0.5 gl resulted in an ethanol yield of 8.7% (m/v) with a fermentation efficiency of 85.12%. Under optimized conditions (35°C) significant improvements were noticed with ethanol yield of 7.8% (m/v) and efficiency of 76.3%.