Jadavpur University

About: Jadavpur University is a education organization based out in Kolkata, India. It is known for research contribution in the topics: Population & Fuzzy logic. The organization has 10856 authors who have published 27678 publications receiving 422069 citations. The organization is also known as: JU & Jadabpur University.

Efficient allylic oxidation of cyclohexene catalyzed by immobilized Schiff base complex using peroxides as oxidants

Abstract: Allylic oxidation of cyclohexene was carried out over a Schiff base copper complex and its immobilized analogue supported on organically modified silica. The immobilized complex has been characterized by using atomic absorption spectrophotometry (AAS), FT-IR, EPR and UV–vis spectroscopic studies and SEM image analysis. The catalytic oxidation of cyclohexene was carried out over this copper complex and the immobilized analog with different oxidants like dilute aqueous hydrogen peroxide and tert-butyl hydroperoxide at ambient conditions. Acetonitrile and water was used as solvent and dispersion medium, respectively, with or without additional acid in different sets of oxidation reactions. 2-Cyclohexen-1-one was obtained as the major product with small amounts of cyclohexene oxide, 2-cyclohexen-1-ol and 1,2-cyclohexane-diol. The activity of the immobilized catalyst remains nearly the same after two cycles, suggesting the true heterogeneous nature of the catalyst.

Tailoring the Magnetic and Optical Characteristics of Nanocrystalline BiFeO3 by Ce Doping

Abstract: The Ce-doped BiFeO3 (BFO) nanoparticles (NPs) were synthesized using a facile solgel route with varying Ce concentrations in the range of 15 mol%. Ferroelectric transition temperature was found to shift from 723 degrees C +/- 5 degrees C for pristine BFO NPs to 534 degrees C +/- 3 degrees C for 5 mol% Ce-doped BFO NPs. UVVis absorption spectra of BFO NPs showed a significant blue shift of similar to 100 nm on Ce doping. The Fourier transformed infrared (FTIR) spectrum centered similar to 550 cm(-1) becomes considerably broadened on Ce doping which is due to additional closely spaced vibrational peaks as revealed by the second derivative FTIR analysis. High-frequency EPR measurements indicated that clustering occurs at high dopant levels, and that Fe is present as Fe(3+)corroborating Mossbauer measurements. The values of saturation and remanent magnetization for 3% Ce-doped BFO NPs are 3.03 and 0.49 emu/g, respectively, which are quite significant at room temperature, making it more suitable for technological applications.

Electronic nose for black tea quality evaluation by an incremental RBF network

Abstract: Black Tea is conventionally tested by human sensory panel called “Tea Tasters”, who assign quality scores to different teas. Electronic nose-based studies aimed at co-relation of sensor array output signature with Tea Tasters’ scores have already been accomplished by the authors with good accuracy [N. Bhattacharyya, R. Bandyopadhyay, M. Bhuyan, B. Tudu, D. Ghosh, A. Jana, Electronic nose for black tea classification and correlation of measurements with “Tea Taster” marks, IEEE Trans. Instrum. Meas. 57 (2008) 1313–1321], where a number of conventional neural network topologies have been explored. One of the principal problems encountered in the above studies is collection of tea samples as tea industries in India are spread over dispersed locations and quality of tea varies considerably on agro-climatic condition, type of plantation, season of flush and method of manufacturing. As a result, the entire dataset is not available at a time and training the conventional neural network models becomes difficult. In this regard, classifiers having the incremental learning ability can be of great benefit by automatically including the newly presented patterns in the training dataset without affecting class integrity of the previously trained system. In the presented paper, the radial basis function (RBF) neural network with the incremental learning feature is used in the pattern recognition algorithm for black tea aroma classification with electronic nose.

Synthesis, Structural Characterization, Photophysical, Electrochemical, and Anion-Sensing Studies of Luminescent Homo- and Heteroleptic Ruthenium(II) and Osmium(II) Complexes Based on Terpyridyl-imidazole Ligand

Abstract: A series of hetero- and homoleptic tridentate ruthenium(II) and osmium(II) complexes of compositions [(tpy-PhCH3)Ru(tpy-HImzphen)](ClO4)2 (1), [(H2pbbzim)Ru(tpy-HImzphen)](ClO4)2 (2), and [M(tpy-HImzphen)2](ClO4)2 [M = RuII (3) and OsII (4)], where tpy-PhCH3 = 4′-(4-methylphenyl)-2,2′:6′,2″-terpyridine, H2pbbzim = 2,6-bis(benzimidazole-2-yl)pyridine and tpy-HImzphen = 2-(4-[2,2′:6′,2″]terpyridine-4′-yl-phenyl)-1H-phenanthro[9,10-d]imidazole, have been synthesized and characterized by using standard analytical and spectroscopic techniques. X-ray crystal structures of three complexes 2, 3, and 4 have been determined. The absorption spectra, redox behavior, and luminescence properties of the complexes have been thoroughly investigated. All of the complexes display moderately strong luminescence at room temperature with lifetimes in the range of 10–55 ns. The effect of solvents on the absorption and emission spectral behavior of the complexes has also been studied in detail. The anion sensing properties of al...

The in situ formation of platinum nanoparticles and their catalytic role in electroactive phase formation in poly(vinylidene fluoride): a simple preparation of multifunctional poly(vinylidene fluoride) films doped with platinum nanoparticles

Abstract: A simple route for in situ platinum nanoparticles (Pt-NPs) synthesis is described. A trace amount (0.048 mM) of platinum precursor promotes the electroactive phase transformations (α → β and γ-phase) in poly(vinylidene fluoride) (PVDF) implying a new catalytic role of Pt-NPs. Furthermore, a complete conversion (∼99%) to the electroactive phase is achieved by simply controlling the platinum precursor amount. The PVDF film doped with Pt-NPs exhibits various functionalities, i.e., human touch response, enhanced ferroelectric remnant polarization and intense photoluminance in the UV-region. Apart from conventional piezoelectric sensors and actuators, it naturally lends itself to futuristic applications as a vibration based energy harvester, a ferroelectric non-volatile memory element and a large area coverage lightweight foldable optoelectronic device.