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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.

The regiochemistry of 1,3-dipolar cycloaddition reactions of C,N-diphenyl nitrone with some vinyl sulfox- imines as dipolarophile was investigated using density functional theory (DFT)-based reactivity indexes and activation energy calculations at B3LYP/6-31G(d) level of theory. Analysis of the geometries and bond orders (BOs) at the TS structures associated with the different reaction pathways shows that these 1,3-dipolar cycloaddition reactions occur via an asynchronous concerted mechanism. Analysis of the local electrophilicity and nucleophilicity indexes permits an interpretation about the regioselectivity of these 1,3-dipolar cycloaddition reactions. The theoretical results obtained in the work clearly predict the regiochemistry of the isolated cycloadducts and agree to experimental outcomes. Copyright © 2011 SIOC, CAS, Shanghai & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mollaiy-Berneti S.,Islamic Azad University at Bandar Abbas
Fuel | Year: 2016

Gas injection process is one of the most efficient improved oil recovery methods for conventional oil reservoirs. The efficiency of this process is strongly dependent on minimum miscibility pressure (MMP) which is usually determined through very expensive and time-consuming laboratory tests. So, this paper is concerned with the use of hybrid approach, combining particle swarm optimization and adaptive neuro-fuzzy inference system (ANFIS) with fuzzy c-means clustering technique, aimed at an estimation of injected gas-reservoir oil MMP. The hybrid proposed model makes ANFIS is practical in dealing with complex and high dimensional MMP problem. The process of model building is done by considering the reservoir temperature, crude oil composition, composition of injected CO2 as input parameters and corresponding CO2-oil MMP information as target parameter. The validity of proposed model has been successfully approved by comparing with results obtained by well-known empirical correlations in published literature. The results show that the proposed model significantly outperformed those four correlations with the lowest mean absolute error of 0.0099, the lowest root mean square error of 0.0174, and the highest coefficient of determination of 0.9823. Therefore, the proposed hybrid model can be applied as an alternative method to yield more accurate results in CO2-oil MMP estimation. © 2016 Elsevier Ltd. All rights reserved.

Feili S.,Islamic Azad University at Bandar Abbas | Hamedi H.R.,Vilnius University
Optics Communications | Year: 2014

A novel scheme is proposed to investigate the possible giant Kerr nonlinearity in a crystal of molecular magnets. The crystal is subjected to one dc magnetic field and two probe and coupling ac magnetic fields. By studying the steady-state behavior of the medium, we show that an enhanced Kerr nonlinearity with negligible absorption can be achieved under condition of slow light levels, just by properly adjusting the coupling field. Also, the transient evolution of nonlinear dispersion is proposed. It is found that the frequency detunings of probe and coupling fields, as well as the intensity of coupling field, lead to the large Kerr nonlinearity. Our results can be used as a guideline for optimizing and controlling the switching process in the crystal of molecular magnets, which is much more practical than that in the atomic system because of its flexible design and the long relaxation times. © 2013 Elsevier B.V. All rights reserved.

The mechanism and regioselectivity of 1,3-dipolar cycloaddition of N-[methyl]-C-[5-nitro-2-furyl] nitrilimine with dimethyl 7-oxabicyclo[2,2,1] hepta-2,5-diene-2,3-dicarboxylate were investigated using activation energy calculations and density functional theory-based reactivity indexes. The reaction proceeds by an asynchronous concerted mechanism. The calculations are performed at the B3LYP/6-31G(d) level of theory and the obtained results are in agreement with experimental outcome. © 2010 Chinese Physical Society.

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