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Islamabad, Pakistan

Iqbal M.S.,Forman Christian College | Khurshid S.J.,Pakistan Atomic Energy Commission | Muhammad B.,Hazara University
Medicinal Chemistry Research | Year: 2013

Mn(II)-, Fe(II)-, Co(II)-, Ni(II)-, and Zn(II)-Schiff base complexes containing anthranilic acid and aldoses as part of the base were prepared and characterized by microanalytical, thermogravimetric, and spectroscopic data. The complexes were found to be four-coordinate, anhydrous, and ML2 type. The spectral and magnetic data indicate a tetrahedral geometry for Mn(II) and Fe(II) complexes, and a planar geometry for Co(II), Ni(II), and Zn(II) complexes. Mn(II) and Zn(II) complexes showed a significant anti-inflammatory activity against kaolin-paw-edema. All the complexes exhibited selective inhibition of COX-2 in two different cell models. © 2012 Springer Science+Business Media, LLC. Source

Iqbal J.,Pakistan Atomic Energy Commission
Proceedings of the Institution of Civil Engineers: Structures and Buildings | Year: 2014

Structures, systems and components that are essential for the safe operation and shutdown of a nuclear power plant may be subject to a variety of impulsive loads. This paper presents an experimental and numerical evaluation of the influence of ground shock and airblast forces on the structural response of a 1:8 scale reactor containment structure founded on schist. The numerical model, including both free air and schist properties, was programmed and linked to finite-element software as its user-provided subroutines. The numerical and experimental scaled model results demonstrate good agreement with each other. The full-scale simulation of typical reactor containment was subjected to surface explosions through the developed relationship for structural response analysis. The proposed methodology can be employed to evaluate the blast response of a concrete shell type containment structure and to estimate the integrity of containment. Source

Rafique E.,Pakistan National Agricultural Research Center | Mahmood-ul-Hassan M.,Pakistan National Agricultural Research Center | Rashid A.,Pakistan Atomic Energy Commission | Chaudhary M.F.,Quaid-i-Azam University
Journal of Plant Nutrition | Year: 2012

A five-year cotton-wheat rotation field experiment was conducted on two alkaline-calcareous soils, i.e., Awagat (coarse loamy) and Shahpur (fine silty), to investigate the impact of integrated nutrient and crop residue management on soil and crop productivity. Apparent nitrogen (N) balances were developed. Minimum five-year mean yield (Mg ha -1), obtained with Farmers' Fertilizer Use (FFU) treatment was: cotton - Awagat, 2.19; Shahpur, 2.45; wheat - Awagat, 3.03; Shahpur, 3.94. With Balance Nutrient Management (BNM), yields increased (P ≤ 0.05) for cotton, 24% in Awagat and 18% in Shahpur soil; and wheat, 37% in Awagat and 24% in Shahpur soil. Maximum crop yields were obtained with Integrated Nutrient Management (INM), i.e., 3-5% higher than with BNM. Crop residue recycling increased the yields further, cotton by 2-7% and wheat by 2-10%. All nutrient management treatments, except for FFU without crop residue recycling, resulted in positive apparent N balances. INM improved SOM and NO 3-N, contents. © 2012 Copyright Taylor and Francis Group, LLC. Source

Ahmed M.,Pakistan Atomic Energy Commission | Kuhlmann H.C.,Vienna University of Technology
Fluid Dynamics Research | Year: 2012

The linear stability of the two-dimensional steady flow in an infinite cavity with a right-angled triangular cross-section is investigated numerically by the finite-element method. We consider the case when one of the walls enclosing the right angle moves away from it. Neutral curves, eigenmodes and kinetic-energy production rates are computed. Five different instability modes are found, depending on the aspect ratio, i.e. the length ratio of the walls enclosing the right angle. The spatial structure of the kinetic-energy transfer between the basic flow and the critical modes indicates that three of the critical modes for very shallow cavities are due to an elliptic instability mechanism. Two other critical modes, for moderately shallow to deep cavities, arise due to a centrifugal mechanism. The instabilities found are discussed and compared with those arising in rectangular cavities. © 2012 The Japan Society of Fluid Mechanics and IOP Publishing Ltd. Source

Qadeer R.,Pakistan Atomic Energy Commission
Journal of Radioanalytical and Nuclear Chemistry | Year: 2013

The batch kinetics of ruthenium ions adsorption on activated charcoal has been investigated over a wide range of ruthenium ions concentration (0.05-0.40 g/L) at room temperature of 23 ± 1 C in 3 M HNO3 solution. The adsorption process of ruthenium ions proceeds via two stages: the first stage is rather fast, followed by slower one, indicative of boundary layer and intra-particle diffusion effects respectively. The mechanism of the adsorption is predominantly diffusion and the intra-particle diffusion played a significant role in rate determining, but it was not the only main rate determining step throughout the adsorption process. Both intra-particle and boundary layer diffusion seem significant in the rate controlling step. It was also observed that the adsorption of ruthenium ions adsorption process is best accounted for using pseudo second order kinetic model and the overall rate of adsorption process appears to be controlled by more than one step, namely the external mass transfer and intra-particle diffusion mechanism. Moreover, the adsorption of ruthenium ions obeys the Freundlich and the Langmuir isotherms in the concentration range studied. © 2012 Akadémiai Kiadó, Budapest, Hungary. Source

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