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Batra N.,GGDSD College | Singh J.,Panjab University | Joshi A.,Shri Guru Gobind Singhji Institute of Engineering and Technology | Bhatia S.,Panjab University
International Journal of Biological Macromolecules | Year: 2011

Bacillus coagulans RCS3 isolated from hot water springs secreted five isozymes i.e. β-gal I-V of β-galactosidase β-gal III isozyme was purified using DEAE cellulose and Sephadex G 100 column chromatography. Its molecular weight characterization showed a single band at 315kD in Native PAGE, while two subunits of 50.1 and 53.7kD in SDS PAGE. β-Gal III had pH optima in the range of 6-7 and temperature optima at 65°C. It preferred nitro-aryl-β-d-galactoside as substrate having K m of 4.16mM with ONPG. More than 85% and 80% hydrolysis of lactose (1-5%, w/v) was recorded within 48h of incubation at 55°C and 50°C respectively and pH range of 6-7. About 78-86% hydrolysis of lactose in various brands of standardized milk was recorded at incubation temperature of 50°C. These results marked the applications of β-gal III in processing of milk/whey industry. © 2011 Elsevier B.V. Source


Kumar R.,GGDSD College | Sekhon S.S.,Guru Nanak Dev University | Sekhon S.S.,University of the West Indies
Ionics | Year: 2013

The addition of polymer to liquid electrolytes containing trifluoromethanesulfonic acid (HCF3SO3) in propylene carbonate (PC) has been found to result in an increase in conductivity of gel electrolytes. The increase in conductivity has been observed to be due to the dissociation of ion aggregates present in the electrolytes which has also been supported by Fourier transform infrared studies. The maximum ionic conductivity (at 25 °C) of 7.55 × 10-3 S/cm has been observed for polymer gel electrolytes containing 1.5 wt% polymethylmethacrylate in 0.5 M solution of HCF3SO3 in PC. Polymer gel electrolytes have been found to be thermally stable up to a temperature of 125 °C by simultaneous differential scanning calorimetry/thermogravimetric analysis studies. The conductivity of polymer gel electrolytes does not show any appreciable change over a limited period of time. © 2013 Springer-Verlag Berlin Heidelberg. Source


Singh J.,Panjab University | Sinha S.,Panjab University | Batra N.,GGDSD College | Joshi A.,Shri Guru Gobind Singhji Institute of Engineering and Technology
Environmental Technology | Year: 2012

Peroxidases have been known to polymerize phenolic compounds and precipitate them from solution. Sapindus peroxidases (SPases) were extracted from the leaves of Sapindus mukorossi and precipitated with four volumes of chilled methanol. Soluble, encapsulated and cross-linked forms of enzymes were used for the removal of phenolic compounds (initial concentration 1.0 mM) in a stirred batch reactor. Calcium alginate beads were prepared using sodium alginate and calcium chloride at 1.5% and 5.0% (w/v), respectively. Sodium alginate and glutaraldehyde at 1.0% (w/v) and 0.8% (v/v), respectively, were optimized for cross-linking of SPases. The maximal removal of 2-chlorophenol was found in the buffers of pH range 4-7 and at 30-60 °C in the presence of 1.2mM H 2O 2 by soluble enzymes, but encapsulated and cross-linked enzymes worked well at pH 5 and at 50 °C in the presence of 0.8mM H 2O 2. The optimized doses of soluble, encapsulated and cross-linked SPases were 1.2, 4.2 and 1.2 mg/mL, respectively, for the removal of phenolic compounds. Encapsulated and cross-linked enzymes showed a lower efficiency than soluble enzyme but can be reused in multiple cycles for the removal of phenolic compounds. © 2012 Taylor & Francis. Source


Dogra S.,GGDSD College | Sharma M.L.,University of Punjab | Singh J.,University of Punjab
Comptes Rendus Chimie | Year: 2015

Various ionic liquids (ILs) were screened for their phase-transfer catalytic (PTC) activity using the N-alkylation of nitrogen heterocycles as the model reaction. Immobilized ILs behaved extremely well and proved to be far better catalysts than conventional homogeneous PTCs in terms of their stability, easy recovery, and reusability. The investigation also demonstrated that quaternary tetraalkylammonium salts offer very high catalytic activity, whereas aromatic heterocyclic tetravalent nitrogen catalysts (imidazolium- and pyridinium-based salts) were poorly active. © 2015 Académie des sciences. Source


Sharma V.K.,Panjab University | Goyal A.,GGDSD College | Raju T.S.,Karunya University | Kumar C.N.,Panjab University | Panigrahi P.K.,Indian Institute of Science
Optical Fiber Technology | Year: 2015

We investigate modulational instability (MI) in a planar dual-core waveguide (DWG), with a Kerr and non-Kerr polarizations based on coupled nonlinear Schrödinger equations in the presence of linear coupling term, coupling coefficient dispersion (CCD) and other higher order effects such as third order dispersion (TOD), fourth order dispersion (FOD), and self-steepening (ss). By employing a standard linear stability analysis, we obtain analytically, an explicit expression for the MI growth rate as a function of spatial and temporal frequencies of the perturbation and the material response time. Pertinently, we explicate three different types of MI-spatial, temporal, and spatio-temporal MI for symmetric/antisymmetric continuous wave (cw), and spatial MI for asymmetric cw, and emphasize that the earlier studies on MI in DWG do not account for this physics. Essentially, we discuss two cases: (i) the case for which the two waveguides are linearly coupled and the CCD term plays no role and (ii) the case for which the linear coupling term is zero and the CCD term is nonzero. In the former case, we find that the MI growth rate in the three different types of MI, seriously depends on the coupling term, quintic nonlinearity, FOD, and ss. In the later case, the presence of quintic nonlinearity, CCD, FOD, and ss seriously enhances the formation of MI sidebands, both in normal as well as anomalous dispersion regimes. For asymmetric cw, spatial MI is dependent on linear coupling term and quintic nonlinearity. Copyright © 2015 Elsevier Inc. All rights reserved. Source

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