Eisazadeh A.,University of Technology Malaysia |
Eisazadeh H.,Shomal University |
Kassim K.A.,University of Technology Malaysia
Synthetic Metals | Year: 2013
In this research, natural sand and clay coated with polyaniline and iron oxide were used to remove Pb(II) from contaminated water. Fixed bed column and batch studies were performed to evaluate the influence of various experimental parameters such as pH, adsorbent dosage, and contact time. Based on the results, optimum conditions for Pb(II) removal were found to be pH 11, adsorbents dosage of 10 g/L, and contact time of 45 min. In addition, the morphology and chemical structure of the adsorbents were studied via scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The column tests were conducted with a flow rate of 4 mL/min with different bed depths of 10 and 25 cm. It was found that when iron oxide/clay, iron oxide/sand, polyaniline/clay and polyaniline/sand were used as adsorbent in a fixed-bed column method, the removal percentages of Pb(II) were 97.50, 99.24, 72.99, 68.80% and for the completely mixed batch reactor (CMBR) method were 99.84, 99.89, 93.91 and 90.77%, respectively. These results indicated that iron oxide coated sand and clay are an attractive source of adsorbents that can be used for removal of Pb(II) in water treatment processes. © 2013 Elsevier B.V. All rights reserved.
Seyedpoor S.M.,Shomal University
Advances in Structural Engineering | Year: 2011
An efficient method is proposed to detect the multiple damages of structural systems. Natural frequency changes of a structure are considered as a criterion for damage presence. Finite element method is also employed to evaluate the required natural frequencies. A multi-stage optimization approach based on the swarm intelligence algorithm is presented to accurately identify the locations and extent of eventual damages. Test example results demonstrate the computational advantages of the proposed method to precisely determine the sites and extent of multiple structural damages.
Saadati R.,Amirkabir University of Technology |
Saadati R.,Shomal University |
Park C.,Hanyang University
Computers and Mathematics with Applications | Year: 2010
Lee et al. considered the following quadratic functional equation f(lx+y)+f(lx-y)=2l2f(x)+2f(y) and proved the HyersUlamRassias stability of the above functional equation in classical Banach spaces. In this paper, we prove the HyersUlamRassias stability of the above quadratic functional equation in non-Archimedean L-fuzzy normed spaces. © 2010 Elsevier Ltd. All rights reserved.
Seyedpoor S.M.,Shomal University
International Journal of Non-Linear Mechanics | Year: 2012
A two-stage method is proposed here to properly identify the site and extent of multiple damage cases in structural systems. In the first stage, a modal strain energy based index (MSEBI) is presented to precisely locate the eventual damage of a structure. The modal strain energy is calculated using the modal analysis information extracted from a finite element modeling. In the second stage, the extent of actual damage is determined via a particle swarm optimization (PSO) using the first stage results. Two illustrative test examples are considered to assess the performance of the proposed method. Numerical results indicate that the combination of MSEBI and PSO can provide a reliable tool to accurately identify the multiple structural damage. © 2011 Elsevier Ltd. All rights reserved.
Bayat M.,Shomal University |
Abdollahzadeh G.,Babol Noshirvani University of Technology
Latin American Journal of Solids and Structures | Year: 2011
The usefulness of supplementary energy dissipation devices is now quite well-known in earthquake structural engineering for reducing the earthquake-induced response of structural systems. The seismic behavior of structures with supplemental ADAS devices is concerned in this study. In this paper, the ratio of the hysteretic energy to input energy is compared in different structural systems. The main purpose of this paper is to evaluate the behavior of structures equipped with yielding dampers (ADAS), located in far fields based on energy concepts. In order to optimize their seismic behavior, the codes and solutions are also presented. Three cases including five, ten and fifteen-story three-bay Concentric Braced Frames (CBF) with and without ADAS were selected. The PERFORM 3D.V4 software along with three earthquake records (Northridge, Imperial Valley and Tabas) is used for nonlinear time history analysis and the conclusions are drawn upon energy criterion. The effect of PGA variation and height of the frames are also considered in the study. Finally, to increase the energy damping ability and reduce the destructive effects in structures on an earthquake event, so that a great amount of induced energy is damped and destruction of the structure is prevented as much as possible by using ADAS dampers.