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Chakrabarty P.P.,Acharya Prafulla Chandra College | Saha S.,Acharya Prafulla Chandra College | Schollmeyer D.,University at Mainz | Boudalis A.K.,Greek National Center For Scientific Research | And 2 more authors.
Journal of Coordination Chemistry | Year: 2013

A new end-to-end azide-bridged one-dimensional coordination polymer, [MnIII(L)(μ1,3-N3)]n (1) (where L represents the dianionic form of the neutral tetradentate Schiff base H2L obtained by 1 : 2 condensation of ethane-1,2-diamine, and 5-chloro-2- hydroxyacetophenone in methanol), has been synthesized and characterized by elemental analyses, IR spectroscopy, single-crystal X-ray diffraction, and variable temperature magnetic study. X-ray crystal structure determination of 1 reveals that a chain system with the repeating unit [MnIII(L) (μ1,3-N3)]n bridged by μ1,3 azide. Each manganese(III) is a distorted octahedral geometry. Variable-temperature magnetic study (between 2 and 300 K) suggests a moderate antiferromagnetic interaction in this complex, similar to other studies reported. © 2012 Taylor & Francis.

Bhattacharyya S.,Acharya Prafulla Chandra College | Saha J.K.,Indian Association for The Cultivation of Science | Mukherjee T.K.,Narula Institute of Technology
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2015

In this work, the controversy between the interpretations of recent measurements on dense aluminum plasma created with the Linac coherent light source (LCLS) x-ray free electron laser (FEL) and the Orion laser has been addressed. In both kinds of experiments, heliumlike and hydrogenlike spectral lines are used for plasma diagnostics. However, there exist no precise theoretical calculations for He-like ions within a dense plasma environment. The strong need for an accurate theoretical estimate for spectral properties of He-like ions in a strongly coupled plasma environment leads us to perform ab initio calculations in the framework of the Rayleigh-Ritz variation principle in Hylleraas coordinates where an ion-sphere potential is used. An approach to resolve the long-drawn problem of numerical instability for evaluating two-electron integrals with an extended basis inside a finite domain is presented here. The present values of electron densities corresponding to the disappearance of different spectral lines obtained within the framework of an ion-sphere potential show excellent agreement with Orion laser experiments in Al plasma and with recent theories. Moreover, this method is extended to predict the critical plasma densities at which the spectral lines of H-like and He-like carbon and argon ions disappear. Incidental degeneracy and level-crossing phenomena are being reported for two-electron ions embedded in strongly coupled plasma. Thermodynamic pressure experienced by the ions in their respective ground states inside the ion spheres is also reported. © 2015 American Physical Society.

pada Das K.,Indian Statistical Institute | Kundu K.,Acharya Prafulla Chandra College | Chattopadhyay J.,Indian Statistical Institute
Ecological Complexity | Year: 2011

A prey-predator model with disease in both the population is proposed and analyzed. Local stability analysis of biologically feasible equilibrium points is worked out with help of ecological as well as disease basic reproduction numbers. We also explain the community composition of ecosystem by basic reproduction numbers. It is shown that the system is globally stable around the interior equilibrium point under certain parametric conditions. Moreover, the system is persistent under some feasible parametric conditions. Our analysis reveals that force of infection and predation rate are the key parameters on the dynamics of the system. Extensive numerical experiments with hypothetical set of parameters are carried out to substantiate our analytical findings. The oscillatory coexistence of the species which is very common in nature is observed for predator disease free system. The introduction of disease in the predator population enhances the extinction of predator population. We also observe that the system will be disease free and all population will persist through proper predational strategies. © 2010 Elsevier B.V.

Saha J.K.,Narula Institute of Technology | Bhattacharyya S.,Acharya Prafulla Chandra College | Mukherjee P.K.,Visva Bharati | Mukherjee P.K.,Ramakrishna Mission Vivekananda University | Mukherjee T.K.,Narula Institute of Technology
Chemical Physics Letters | Year: 2011

It is shown for the first time that the analytic form of the wavefunction reveals the real reason behind the dominance of fluorescence decay over autoionization for some doubly excited states of helium without entering into detailed calculation of transition rates. It is remarkable that the angular part of the wavefunction for fluorescence active autoionizing states are same as that of the bound states of that particular symmetry. Subsequently, a criteria has been set up to diagnose the fluorescence active doubly excited states of helium. © 2011 Elsevier B.V. All rights reserved.

Bhattacharyya S.,Auburn University | Bhattacharyya S.,Acharya Prafulla Chandra College | Saha J.K.,Narula Institute of Technology | Mukherjee P.K.,Ramakrishna Mission Vivekananda University | Mukherjee T.K.,Narula Institute of Technology
Physica Scripta | Year: 2013

The effect of spherical confinement on the ground state of helium-like ions (Z = 1-5) and the first four (1Se) excited states for Z = 2-5 have been analyzed in detail by using correlated Hylleraas basis sets within the variational framework. The correlated wave functions used here are consistent with the finite boundary conditions due to spherical confinement. The present energy values and the thermodynamic pressure generated for the confined ions as well as the critical values of the confining radii close to the fragmentation limit can be set as a benchmark for future references. © 2013 The Royal Swedish Academy of Sciences.

Das A.,Acharya Prafulla Chandra College | Bhadra S.,Acharya Prafulla Chandra College | Saha S.,Sarojini Naidu College for Women
Quantum Information Processing | Year: 2015

Quantum phase transition in dimerised antiferromagnetic Heisenberg spin chain has been studied. A staircase structure in the variation of concurrence within strongly coupled pairs with that of external magnetic field has been observed indicating multiple critical (or critical like) points. Emergence of entanglement due to external magnetic field or magnetic entanglement is observed for weakly coupled spin pairs too in the same dimer chain. Though closed dimerised isotropic XXX Heisenberg chains with different dimer strengths were mainly explored, analogous studies on open chains as well as closed anisotropic (XX interaction) chains with tilted external magnetic field have also been studied. © 2015, Springer Science+Business Media New York.

Bhattacharyya S.,Acharya Prafulla Chandra College
Journal of Physics: Conference Series | Year: 2015

Helium-like ions of carbon, aluminum and argon surrounded by strongly coupled plasma have been studied in the framework of ion-sphere potential. A methodology for evaluating two-electron correlated integrals in finite domain have been developed for this purpose. © Published under licence by IOP Publishing Ltd.

Das A.,Acharya Prafulla Chandra College
Environmental Modeling and Assessment | Year: 2015

Copula functions are useful in constructing multivariate distributions using various marginal distributions and non-linear dependence structures. This paper uses copula functions to construct multivariate distributions with one-sided marginal distributions and copula-based regression to estimate the arsenic exposure in urine using arsenic intake through water and diet as potential covariates in a study in West Bengal, India. As arsenic concentration in urine, water, and diet takes only positive values and negative amount of arsenic concentration in urine, water, and diet are impossibility, one-sided distribution with positive real line support is assumed for these characteristics. Gaussian and Farlie-Gumbel-Morgenstern (FGM) families of copula are considered to capture the non-linear association among these variables. The maximum likelihood method is applied to estimate the parameters of the models. The estimation result suggests that the covariates significantly affect the urinary arsenic exposure, and arsenic intake through diet was a potential contributor of urinary arsenic exposure even when arsenic intake through water was reduced significantly in this arsenic-affected region of West Bengal. © 2014, Springer International Publishing Switzerland.

Chakrabarty P.P.,Acharya Prafulla Chandra College | Biswas D.,Acharya Prafulla Chandra College | Garcia-Granda S.,University of Oviedo | Jana A.D.,Behala College | Saha S.,Acharya Prafulla Chandra College
Polyhedron | Year: 2012

Syntheses, characterization and crystal structures of three new sodium based heterotrinuclear ionic clusters [(CuL1) 2Na(ClO 4-O,O′)(OH 2)]·C 8H 8O 2 (1), [(CuL2) 2Na(ClO 4-O,O′) ] (2) and [{Cu(L3) 2} 2Na] +·ClO 4 - (3) derived from three different Schiff bases (L1 = 1:2 condensation of 1,2-propane diamine and o-hydroxy acetophenone, L2 = 1:2 condensation of 1,2-propane diamine and 2-hydroxy-5-methoxy acetophenone and L3 = 1:1 condensation of 2-amino pyridine and 3-ethoxy salicylaldehyde) are reported herein. The crystal structure analysis reveals that the square-planar Cu-ligand complexes act as building block for the trinuclear complex in which Na + ion guides the orientation of Cu(II) Schiff-base complexes into a scissor like architecture in 1 and 2. The unique assembling feature of Na + ion is also evident in complex 3 where even in the presence of a widely different Schiff-base ligand, Na + guides two Cu(II)(L3) 2 complexes to assemble around it in a crown ether like environment. In complexes 1 and 2 the square planar metal coordination provide suitable sites for chelate ring π···π interaction and Cu···π interaction which ensures columnar assembly of trinuclear units at the supramolecular level. The present study reveals the unique nature of the self-assembly of square-planar Cu(II) Schiff-base complexes around Na +. © 2012 Elsevier Ltd. All rights reserved.

PubMed | Acharya Prafulla Chandra College and Manipur University
Type: | Journal: Radiation protection dosimetry | Year: 2017

The suitability of the second derivative method for locating component peaks in complex thermoluminescence (TL) glow curves has been investigated in this work by considering both numerically simulated and experimental TL peaks. This technique is useful to acquire knowledge of the number of component peaks in a complex TL curve which in turn serves as a basic information before applying the deconvolution technique to the glow curve. To check the consistency of the results so obtained, we have also applied the first derivative technique to TL glow curves. It is well-known that kinetic order formalism fails for saturated TL peaks with heavy retrapping. Such peaks are usually broad and, to the best of our knowledge, have not yet been observed experimentally. The present derivative technique has been used to detect whether such broad peaks are truly single or not by considering a number of numerically simulated saturated glow curves with heavy retrapping where the conventional peak shape method fails. In all the cases considered here, the second derivative technique proves to be a potential candidate for estimating the number of peaks and their respective locations in a complex TL glow curve.

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