Time filter

Source Type

Kolkata, India

Aliah University , is a state government controlled minority autonomous university in Salt Lake, West Bengal, India. Previously known as Mohammedan College of Calcutta, it was elevated to university in 2008. It offers multiple modern day professional undergraduate and postgraduate programs in different Engineering, Arts, Science and Management subjects respectively. Professor Abu Taleb Khan is its present vice chancellor. Wikipedia.

The paper deals with the dynamical behavior of fish and mussel population in a fish farm where external food is supplied. The ecosystem of the fish farm is represented by a set of nonlinear differential equations involving nutrient (food), fish and mussel. We have listed some results already obtained. We have analyzed for the direction of Hopf-bifurcation, stability of the Hopf-bifurcating periodic orbits, and the period of the periodic orbits by using Poincare' normal form and center manifold theory. We have performed numerical simulation to support the analytical results. © 2011 Elsevier Inc. Source

Dalapati S.,University of Calcutta | Jana S.,University of Calcutta | Alam M.A.,Aliah University | Guchhait N.,University of Calcutta
Sensors and Actuators, B: Chemical | Year: 2011

Unsymmetrical azine Schiff base 5-diethylamino-2-[(4-diethylamino- benzylidene)-hydrazonomethyl]-phenol (receptor 1) having multiple binding sites (-NEt2 and -OH group) have been synthesized. The receptor 1 exhibits color change from light yellow to purple and bright yellow in presence of Cu2+ ion and Fe3+ ion, respectively which is detectable by naked-eye. But it shows red color in presence of mixture of all metal ions. The UV-vis spectral investigation of receptor 1 shows a remarkable spectral shift from 410 nm to 527, 572 and 620 nm in presence of Cu2+ ion and 485 nm in presence of Fe3+ ion in acetonitrile solvent. Interestingly, Cu2+ ions generates a new charge transfer emission band at 532 nm in the expense of local emission of receptor at 480 nm, but Fe3+ ion only quenched the local emission. The spectral response of receptor is almost insignificant in presence of other metal ions (Mn2+, Zn2+, Co2+, Ni2+, Cd2+, Hg2+, Li + and Na+ ions). © 2011 Elsevier B.V. All rights reserved. Source

Khan M.A.,Aliah University
International Journal of Modern Physics E | Year: 2015

In this paper, hyperspherical three-body model formalism has been applied for the calculation of energies of the low-lying bound 3S-states of neutral helium and helium like Coulombic three-body systems having nuclear charge (z) in the range 2 ≤ Z ≤ 92. Energies of 1S-states are also calculated for those having nuclear charge in the range 14 ≤ Z ≤ 92. The calculation of the coupling potential matrix elements of the two-body potentials has been simplified by the use of Raynal-Revai Coefficients (RRC). The three-body wave function in the Schrödinger equation when expanded in terms of hyperspherical harmonics (HH), leads to an infinite set of coupled differential equation (CDE) which for practical purposes is truncated to a finite set and the truncated set of CDE's are solved by renormalized Numerov method (RNM) to get the energy (E). The calculated energy is compared with the ones of the literature. © 2015 World Scientific Publishing Company. Source

Datta S.,Sn Bose National Center For Basic Science | Rahaman B.,Aliah University
AIP Advances | Year: 2015

Spin-polarized DFT has been used to perform a comparative study of the geometric structures and electronic properties for isolated M4X4 nano clusters between their two stable isomers - a planar rhombus-like 2D structure and a cubane-like 3D structure with M = Mn, Fe, Co, Ni, Cu; X = O, S. These two structural patterns of the M4X4 clusters are commonly found as building blocks in several poly-nuclear transition metal complexes in inorganic chemistry. The effects of the van der Waals corrections to the physical properties have been considered in the electronic structure calculations employing the empirical Grimme's correction (DFT+D2). We report here an interesting trend in their relative structural stability - the isolated M4O4 clusters prefer to stabilize more in the planar structure, while the cubane-like 3D structure is more favorable for most of the isolated M4S4 clusters than their planar 2D counterparts. Our study reveals that this contrasting trend in the relative structural stability is expected to be driven by an interesting interplay between the s-d and p-d hybridization effects of the constituents' valence electrons. © 2015 Author(s). Source

Khan M.A.,Aliah University
Few-Body Systems | Year: 2014

The energies of the low-lying bound S-states of some two-electron systems (treating them as three-body systems) like negatively charged hydrogen, neutral helium, positively charged-lithium, beryllium, carbon, oxygen, neon, argon and negatively charged muonium and exotic positronium ions have been calculated employing hyperspherical harmonics expansion method. The matrix elements of two-body interactions involve Raynal–Revai coefficients which are particularly essential for the numerical solution of three-body Schrődinger equation when the two-body potentials are other from Coulomb or harmonic. The technique has been applied for to two-electron ions 1H− (Z = 1) to 40Ar16+ (Z = 18), negatively charged-muonium Mu− and exotic positronium ion Ps−(e+e−e−) considering purely Coulomb interaction. The available computer facility restricted reliable calculations up to 28 partial waves (i.e. Km = 28) and energies for higher Km have been obtained by applying an extrapolation scheme suggested by Schneider. © 2014, Springer-Verlag Wien. Source

Discover hidden collaborations