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 & Fuzzy logic. The organization has 15254 authors who have published 31165 publications receiving 487551 citations. The organization is also known as: Tehran Polytechnic & Tehran Polytechnic University.

Thermal buckling of temperature dependent FG-CNT reinforced composite plates

Abstract: Thermally induced bifurcation buckling of rectangular composite plates reinforced with single walled carbon nanotubes is investigated in this research. Distribution of CNTs across the thickness of the plate is considered to be uniform or functionally graded. Thermomechanical properties of the constituents are considered to be temperature dependent. Equivalent properties of the composite media are obtained by means of a modified rule of mixtures approach. First order shear deformation plate theory is used to formulate the governing equations. An energy based Ritz method is used to obtain the algebraic presentation of the stability equations. Due to their fast convergence feature, Chebyshev polynomials are adopted as the basis of the shape functions. Various combinations of clamped, simply supported, sliding supported and free boundary conditions with normal to edge immovable or movable features are considered. An iterative process is applied to obtain the critical buckling temperature of composite plates with temperature dependent material properties. Numerical result are given to explore the influences of various parameters such as characteristics of CNTs, geometrical characteristics of the plate and boundary conditions. It is shown that, in most of the cases, FG-X pattern of the CNTs is the most influential case since it results in higher critical buckling temperatures.

Cellulose-graft-polyacrylamide/hydroxyapatite composite hydrogel with possible application in removal of Cu (II) ions

Abstract: Cellulose- graft -polyacrylamide/hydroxyapatite composite hydrogels of different weight ratios were prepared through a suspension polymerization method. Physical and chemical characteristics of the composite were investigated by Fourier transform infrared spectroscopy and scanning electron microscopy. The swelling behaviors of the composite hydrogels were investigated under varying conditions of time, temperature and pH. The optimized swelling capacity in standard conditions was found to be 5197% per gram of the hydrogel. The prepared hydrogel has the potential to be used for ion adsorption in water treatment. Such a possibility was examined through adsorption of copper (II) ions from an aqueous solution. The effects on adsorption of varying the time, pH, and initial concentration of copper (II) solution as well as some thermodynamic parameters were also investigated. The maximum adsorption capacity was found to be 175 mg per gram of composite hydrogel in dried state. The mechanism of adsorption was well presented using a pseudo-second-order kinetic model. Finally, the mercury-loaded hydrogel was regenerated without losing its original activity and stability.