Amirkabir University of Technology

About: Amirkabir University of Technology is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Nonlinear system & Finite element method. The organization has 15254 authors who have published 31165 publications receiving 487551 citations. The organization is also known as: Tehran Polytechnic & Tehran Polytechnic University.

Microstructure and failure behavior of dissimilar resistance spot welds between low carbon galvanized and austenitic stainless steels

Abstract: Resistance spot welding was used to join austenitic stainless steel and galvanized low carbon steel. The relationship between failure mode and weld fusion zone characteristics (size and microstructure) was studied. It was found that spot weld strength in the pullout failure mode is controlled by the strength and fusion zone size of the galvanized steel side. The hardness of the fusion zone which is governed by the dilution between two base metals, and fusion zone size of galvanized carbon steel side are dominant factors in determining the failure mode.

Removal of Cu2+, Pb2+ and Cr6+ from aqueous solutions using a chitosan/graphene oxide composite nanofibrous adsorbent

Abstract: A novel electrospun chitosan/graphene oxide (GO) nanofibrous adsorbent was successfully developed by an electrospinning process. The adsorption behaviors of Cu2+, Pb2+ and Cr6+ metal ions from aqueous solutions using chitosan/GO nanofibers were investigated. The composite nanofibers were characterized by FTIR and SEM and TEM analysis. Kinetic and equilibrium studies showed that the experimental data of Cu2+, Pb2+ and Cr6+ were best described by double-exponential kinetic and Redlich–Peterson isotherm models. The maximum monolayer adsorption capacity of Pb2+, Cu2+and Cr6+ metal ions using chitosan/GO nanofibers was found to be 461.3, 423.8 and 310.4 mg g−1 at an equilibrium time of 30 min and temperature of 45 °C. Evaluation of the thermodynamic parameters (ΔG° 0 and ΔS° > 0) showed that the nature of the metal ions sorption by chitosan/GO nanofibers was endothermic and spontaneous. The reusability studies indicated that the chitosan/GO nanofibers could be reused frequently without almost any significant loss in adsorption performance. This study provides a promising chitosan/GO nanofibrous adsorbent with an efficient adsorption property for heavy metal ions removal.