Malekzadeh P.,Persian Gulf University
Composite Structures | Year: 2011
The thermal buckling analysis of functionally graded (FG) arbitrary straight-sided quadrilateral plates is presented. The material properties are assumed to be temperature-dependent and graded in the thickness direction. The thermal buckling equilibrium equations are based on the three-dimensional (3D) elasticity theory. The differential quadrature method as an efficient and accurate numerical tool is adopted to discretize the governing equations. The principle of virtual work in conjunction with the geometric mapping technique is used to derive the equilibrium equations and the related boundary conditions. After discretizing the governing equations, the resulting nonlinear eigenvalue system of equations is solved by an iterative procedure. The convergence of the method is shown through different examples and its accuracy is demonstrated by comparing the obtained solutions with the existing results in literature for FG plates. Finally, the effects of temperature dependence of material properties, temperature field, volume fraction index, geometrical parameters and the boundary conditions on the thermal buckling characteristic of the FG plates of various shapes are studied. © 2010 Elsevier Ltd.
Shekouhy M.,Islamic Azad University at Bandar Abbas |
Hasaninejad A.,Persian Gulf University
Ultrasonics Sonochemistry | Year: 2012
A catalyst-free one-pot four component methodology for the synthesis of 2H-indazolo[2,1-b]phthalazine-triones under ultrasonic irradiation at room temperature using 1-butyl-3-methylimidazolium bromide, [Bmim]Br, as a neutral reaction medium is described. A broad range of structurally diverse aldehydes (aromatic aldehydes bearing electron withdrawing and/or electron releasing groups as well as heteroaromatic aldehydes) were applied successfully, and corresponding products were obtained in good to excellent yields without any byproduct. © 2011 Elsevier B.V. All rights reserved.
Gheisari R.,Persian Gulf University
Nuclear Fusion | Year: 2010
The emission of tμ atoms in a two-layer arrangement consisting of H/T and D2 is investigated with an alternative kinetic model. The slowing down of tμ(1s) atoms in pure deuterium and their falling down into resonance regions force chemical confinement fusion (μCF). By considering the resonance escape probability of tμ(1s) atoms, point kinematic equations are numerically solved to obtain the muon conversion efficiency and also the cycling coefficient. Under the optimal condition we show that the μ-cycling coefficient and the efficiency equal 104.5 ± 2.5 and ∼0.7%, respectively. Our model is compared with previous suggestions. The muon conversion efficiency is estimated for a possible design and compared with recent experimental results for H/T ⊕ D/T. © 2010 IAEA, Vienna.
Hashemi M.,Persian Gulf University
Journal of Organometallic Chemistry | Year: 2015
The structures of [Pt(bpy)R2] complexes (bpy = 2,2′-bipyridine, R = Me, Ph, 4-MeC6H4, 4-MeOC6H4, 3-MeOC6H4, 4-NMe2C6H4, 4-FC6H4, 3-FC6H4, 4-ClC6H4, CCH, CCPh, CF3, CN) were optimized. Energy of neutral, cationic and anionic forms of these complexes were calculated at the B3LYP/6-311G(d,p) level of theory. Nucleophilicity indexes and electron-donating powers were calculated for these complexes. A relatively good correlation for nucleophilicity index and a very good correlation for electron-donating power were found between these descriptors and logk2 (when available) (k2 is the second order rate constants for oxidative addition of methyl iodide on these complexes). Also a good correlation was found between the energy of platinum dZ2 orbital and logk2. The condensed-to-atom Fukui functions for nucleophilic and electrophilic attacks on these complexes show that in all of these complexes, Pt center is the especially preferable site for electrophilic attack. These observations support the mechanism of SN2 type for oxidative addition of polar organic reagents on organoplatinum(II) complexes. © 2014 Elsevier B.V. All rights reserved.
Spectrophotometric simultaneous determination of metal ions in cows' milk and vegetables with the aid of artificial neural networks using synthetic 2-benzylspiro[isoindoline-1,5'-oxazolidine]-2',3,4'-trione
Abbasi-Tarighat M.,Persian Gulf University
Journal of the Science of Food and Agriculture | Year: 2014
BACKGROUND: A simple, selective and sensitive multi-component method for the simultaneous determination of Zn2+, Mn2+ and Fe3+ based on complex formation with 2-benzylspiro[isoindoline-1,5'-oxazolidine]-2',3,4'-trione using artificial neural networks is proposed. RESULTS: The analytical data showed that metal-to-ligand ratios in Zn2+ and Fe3+ complexes was 1:1 and for Mn2+ complex was 1:2. It was found at pH 6.5 and 5 min after mixing, the complexation reactions were completed. The coloured complexes exhibited absorption bands in the wavelength range 200-400 nm. The results showed that Zn2+, Mn2+ and Fe3+ could be determined in the range 0.1-18.0, 0.3-10.0 and 0.5-20.0 mg L-1, respectively. CONCLUSION: The data obtained from synthetic mixtures of metal ions were processed by radial basis function networks (RBFNs) and back-propagation neural network. The optimal conditions of the neural networks were obtained by adjusting various parameters. Satisfactory precision and accuracy were obtained with all networks, although, because of surprisingly lower root mean square error (%) values, RBFNs were the preferred approach. The proposed approach was tested by analysing the composition of the different mixtures containing Zn2+, Mn2+ and Fe3+. The proposed method was successfully applied to the simultaneous determination of Zn2+, Mn2+ and Fe3+ ions in milk and vegetable samples. © 2013 Society of Chemical Industry.