Reusable and Efficient Polystyrene Immobilized Ionic Liquid Catalyst for Batch and Flow Methylation of Hydroquinone

Catalysis Letters - An environmentally benign process for synthesizing 4-methoxyphenol through methylation of hydroquinone using polystyrene immobilized Bronsted acidic ionic liquid is presented....     

Design of Smart Door Closer System with Image Classification over WLAN

Wireless Personal Communications - A dual purpose system is presented in this paper which serves not only as a door closer, but is equally effective for surveillance purposes. The currently...     

PRATIT: a CNN-based emotion recognition system using histogram equalization and data augmentation

Multimedia Tools and Applications - Emotions are spontaneous feelings that are accompanied by fluctuations in facial muscles, which leads to facial expressions. Categorization of these facial...     

ROLE OF COMPOSITION ON THE VISCOSITY AND SHEAR STRESS TEMPERATURE BEHAVIOUR OF SOME LUBE OIL BASE STOCKS

Lubricating oil base stocks differ greatly in their chemical composition and consequently in their physical properties and applications. Influence of waxes and various hydrocarbon type constituents viz saturates and aromatic components on the viscosity and shear stress as a function of temperature in different lube oil base stocks has been studied in the present paper.     

Analysis of laser source nonlinearity due to longitudinal mode-hopping

The nonlinearity of a frequency-ramped single-mode laser source to be used in optical heterodyne interferometry has been investigated. The analysis is based on mode-hopping due to variation in injection current, temperature and mismatch reflections.     

Purification, kinetic characterization and involvement of tryptophan residue at the NADPH binding site of xylose reductase from Neurospora crassa

Xylose reductase (XR) from Neurospora crassa was purified to homogeneity and was found to be specific to NADPH (nicotinamide adenine dinucleotide phosphate). The purified enzyme showed M(r) of 60 and 29 kDa by gel filtration and SDS-PAGE indicating the presence of two subunits. The kinetic mechanism of xylose reductase is 'iso-ordered bi bi'. Inactivation of XR by N-bromosuccinimide (NBS) was found to be biphasic with second-order rate constants of 2.5 x 10(2) and 80 M-1S-1 for the fast (kf) and slow phase (ks), respectively. NADPH protected 90% of XR activity against inhibition by NBS. The fluorescence and circular dichroism (CD) studies revealed that inactivation was not due to gross conformational change in the enzyme. Analysis of the modified Stern-Volmer plot indicated that 49% of the tryptophanyl fluorescence was available for quenching which was completely abolished in the presence of NADPH confirming the involvement of tryptophan at the coenzyme binding site. Experimental evidence presented here serves to implicate the involvement of a tryptophan residue at the low-affinity NADPH binding site and the nature of this site has been assessed by using the hydrophobic probe ANS.     

Methacrylic acid and dodecyl methacrylate (MAc‐DMA) hydrogel for enhanced catalytic activity of lipase of Bacillus coagulans MTCC‐6375

An alkaline thermotolerant bacterial lipase of Bacillus coagulans MTCC‐6375 was purified and immobilized on a methacrylic acid and dodecyl methacrylate (MAc‐DMA) hydrogel. The lipase was optimally bound to the matrix after 20 min of incubation at 55°C and pH 9 under shaking conditions. The matrix‐bound lipase retained approximately 50% of its initial activity at 70–80°C after 3 h of incubation. The immobilized lipase was highly active on medium chain length p‐nitrophenyl acyl ester (C: 8, p‐nitrophenyl caprylate) than other p‐nitrophenyl acyl esters. The presence of Fe³⁺, NH₄⁺, K⁺, and Zn²⁺ ions at 1 mM concentration in the reaction mixture resulted in a profound increase in the activity of immobilized lipase. Most of the detergents partially reduced the activity of the immobilized lipase. The immobilized lipase performed ～62% conversion in 12 h at temperature 55°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1420–1426, 2006     

Model development and validation: Co-combustion of residual char, gases and volatile fuels in the fast fluidized combustion chamber of a dual fluidized bed biomass gasifier

A one-dimensional steady state model has been developed for the combustion reactor of a dual fluidized bed biomass steam gasification system. The combustion reactor is operated as fast fluidized bed (riser) with staged air introduction (bottom, primary and secondary air). The main fuel i.e., residual biomass char (from the gasifier), is introduced together with the circulating bed material at the bottom of the riser. The riser is divided into two zones: bottom zone (modelled according to modified two phase theory) and upper zone (modelled with core-annulus approach). The model consists of sub-model for bed hydrodynamic, conversion and conservation. Biomass char is assumed to be a homogeneous matrix of C, H and O and is modelled as partially volatile fuel. The exit gas composition and the temperature profile predicted by the model are in good agreement with the measured value.     

IEVCA: An efficient image encryption technique for IoT applications using 2-D Von-Neumann cellular automata

Multimedia Tools and Applications - Present era is marked by exponential growth in transfer of multimedia data through internet. Most of the Internet-of-Things(IoT) applications send images to...