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Mehdipour I.,Islamic Azad University at Buinzahra | Ghazavi M.,K. N. Toosi University of Technology | Moayed R.Z.,Imam Khomeini International University
Geotextiles and Geomembranes | Year: 2013

Geocell reinforced soil may be used in many areas of geotechnical engineering, however, there is little information on analysis of the behavior of geocell reinforced slopes. Due to the height of the geocell, the geocell-reinforced mattress more likely provides a beam or plate effect than a planar membrane effect. The purpose of this paper is to use beam model to simulate the geocell behavior as a flexible slab foundation which can carry both bending and membrane stresses for stability analysis of geocell reinforced slopes. In addition, the interface resistance between the geocell-soil was considered. The Young's modulus of geocell encased soil was obtained from the elastic modulus of the unreinforced soil and the tensile modulus of the geocell reinforcement using an empirical equation. Parametric studies of geocell reinforced slope are carried out by varying placement depth of the geocell layer, number of geocell layers, vertical spacing between reinforcement layers, length, thickness and Young's modulus of the geocell reinforcement. The influence of slope geometry, shear strength properties and soil compaction on the behavior of geocell reinforced slope is also discussed. The obtained results show that geocell reinforcement acts as a wide slab and thus it can restrain the failure surface from developing and redistribute the loads over a wider area. Therefore, under the geocell placement, the lateral deformation and shear strain values of the slope considerably decrease. Furthermore, the effective placement of geocell reinforcements is found to be between the middle of the slope and the middle of critical failure surface of the unreinforced slope. © 2013 Elsevier Ltd.

Nasrollahzadeh M.,University of Qom | Sajadi S.M.,Kurdistan Regional Government | Khalaj M.,Islamic Azad University at Buinzahra
RSC Advances | Year: 2014

This paper reports on the biosynthesis of copper nanoparticles (NPs) using extract of the Euphorbia esula L leaves as reductant and stabilizer without any surfactant. The catalytic efficiency of the prepared Cu NPs for the reduction of 4-nitrophenol and ligand-free Ullmann-coupling reaction is discussed. The Cu NPs were characterized with UV-vis, XRD and TEM methods. This method has the advantages of high yields, simple methodology, and elimination of ligand and easy work up. This journal is © the Partner Organisations 2014.

Gharagheizi F.,Islamic Azad University at Buinzahra
Fluid Phase Equilibria | Year: 2012

In this study, a new eight-parameter equation is presented for calculation/prediction of the normal boiling vaporization enthalpy of pure chemical compounds. The model variables include seven molecular-based descriptors in addition to the normal boiling point temperature. The model is developed using the Genetic-Algorithm-based Multivariate Linear Regression (GA-MLR) method. The GA-MLR is applied to select the parameters of the model from more than 3000 molecular-based parameters in addition to the normal boiling point. To propose a comprehensive and predictive model, 4879 pure chemical compounds are investigated. Furthermore, several statistical methods are implemented to evaluate the predictive power of the model. The root mean square of error and the average absolute deviation of the model are approximately equal to 1.8. kJ/mol and 2.3%. © 2012 Elsevier B.V.

Nasrollahzadeh M.,University of Qom | Enayati M.,University of Qom | Khalaj M.,Islamic Azad University at Buinzahra
RSC Advances | Year: 2014

A new method for the synthesis of N-arylureas and their N-arylation with aryl halides has been developed using copper nanoparticles supported on natural Natrolite zeolite as a reusable heterogeneous catalyst under ligand-free conditions. © 2014 the Partner Organisations.

Nasrollahzadeh M.,University of Qom | Maham M.,Islamic Azad University | Ehsani A.,University of Qom | Khalaj M.,Islamic Azad University at Buinzahra
RSC Advances | Year: 2014

This paper reports on the synthesis and use of palladium on nano-magnetite as a magnetically separable catalyst for copper- and ligand-free Songashira and Stille coupling reactions. The catalyst was characterized using powder XRD, SEM, EDS and VSM techniques. This method has the advantages of high yields, simple methodology and easy work-up. Catalytic efficiency remains unaltered even after several repeated cycles. © 2014 the Partner Organisations.

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