Ghasemzadeh M.A.,Islamic Azad University at Qom
Quimica Nova | Year: 2017
In this research a highly efficient one-pot preparation of tricarboxamide derivatives via five-component reactions of isocyanides, aldehydes Meldrum's acid and 2equiv. of amines have been developed in the presence of Fe3O4@SiO2-OSO3H nanocomposite. Nano-Fe3O4 encapsulated-silica particles bearing sulfonic acid was readily recovered using an external magnet and could be reused several times without significant loss of reactivity. The catalyst was fully characterized by VSM, FT-IR, SEM, XRD, EDX and TEM analysis.
Nasrollahzadeh M.,University of Qom |
Zahraei A.,Islamic Azad University at Qom |
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 a nanopolymer supported copper(ii) complex, as a separable catalyst for the formamidation of arylboronic acids under aerobic conditions. The catalyst was characterized using powder XRD, SEM, EDS, TGA-DTG and FT-IR spectroscopy. This method has the advantages of high yields, elimination of homogeneous catalysts, simple methodology and easy work up. Catalytic efficiency remains unaltered even after several repeated cycles. The synthesized catalyst is found to be more highly toxic towards Gram-positive bacteria than Gram-negative bacteria. This journal is © the Partner Organisations 2014.
Ghasemzadeh M.A.,Islamic Azad University at Qom |
Elyasi Z.,Islamic Azad University at Qom
Iranian Journal of Catalysis | Year: 2017
This study introduces a green and efficient method for preparation of biologically-active substituted 4H-pyrans using the onepot three-component reaction of aromatic aldehydes, dimedone and malononitrile in the presence of cobalt oxide nanoparticles. Co3O4 nanoparticles were used as an efficient catalyst for the synthesis of polyhydroquinoline derivatives by the reaction of aromatic aldehydes, ethyl acetoacetate, dimedone and ammonium acetate. The preparation and use of Co3O4 as a powerful and reusable nanocatalyst under solvent-free conditions is described. The catalyst was characterized by spectral techniques including XRD, FE-SEM, FT-IR, VSM, EDX and TEM analysis. This method offers the advantages of high yield, short reaction time, comfortable work-up and reusability of the catalyst.
Yusofi E.,Islamic Azad University at Tehran |
Mohsenzadeh M.,Islamic Azad University at Qom
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014
Recent Planck results motivated us to use non-Bunch-Davies vacuum. In this paper, we use the excited-de Sitter mode as non-linear initial states during inflation to calculate the corrected spectra of the initial fluctuations of the scalar field. First, we consider the field in de Sitter space-time as background field and for the non-Bunch-Davies mode, we use the perturbation theory to the second order approximation. Also, unlike conventional renormalization method, we offer de Sitter space-time as the background instead Minkowski space-time. This approach preserve the symmetry of curved space-time and stimulate us to use excited mode. By taking into account this alternative mode and the effects of trans-Planckian physics, we calculate the power spectrum in standard approach and Danielsson argument. The calculated power spectrum with this method is finite, corrections of it is non-linear, and in de Sitter limit corrections reduce to linear form that obtained from several previous conventional methods. © 2014 Elsevier B.V.
Mollaamin F.,Islamic Azad University at Qom |
Monajjemi M.,Islamic Azad University at Tehran
Journal of Computational and Theoretical Nanoscience | Year: 2012
Polymer composites, in general, are made by incorporating filler particles into a polymer matrix. These materials are of major interest, especially when a combination of properties which cannot be obtained in a single material is required. carbon-nanotube (CNT) polymer composites have been a fertile area for modeling studies of microwave dynamics, percolation, and elasticity network formation. Nanocomposite materials have become increasingly important due to their extraordinary properties, which arise from the synergism between the properties of the parent components and their unique interfacial characteristics. Polymer Nanocomposites considerable interest because of the potential applications of these composites in many areas where a certain level of conductivity is required. The ubiquitous research that focus on multiscale modeling has broached different disciplines including solid mechanics, fluid mechanics, materials science, physics, mathematics, biological, and chemistry. In this work, the model has been considered for conductivity of carbonnanotube polymer composites (CNTC) focused on such polymer nanocomposites that can conduct electrical currents upon percolation theory and fractals. Copyright © 2012 American Scientific Publishers.
Panahi-Kalamuei M.,University of Kashan |
Mousavi-Kamazani M.,Islamic Azad University at Kashan |
Salavati-Niasari M.,University of Kashan |
Hosseinpour-Mashkani S.M.,Islamic Azad University at Qom
Ultrasonics Sonochemistry | Year: 2015
Selenium (Se) nanostructures were synthesized by a sonochemical method using SeCl4 as a new precursor for Se nanostructures. Moreover, hydrazine, potassium borohydride, and thioglycolic acid were used as reducing reagents in aqueous solution. Ultrasonic power, irradiation time, reducing agent, solvent, HCl, NaOH, and the surfactant were changed in order to investigate the effect of preparation parameters on the morphology and particle size of selenium. The obtained Se with different morphologies and sizes was characterized by XRD, SEM, TEM, EDS, and DRS. The selenium nanostructures exhibited enhanced photocatalytic activity in the degradation of methylene blue (MB) under visible light irradiation. Furthermore, to examine the solar cell application of as-synthesized selenium nanostructure, FTO/TiO2/Se/Pt-FTO and FTO/Se/CdS/Pt-FTO structures were created by deposited selenium film on top of the TiO2 layer and FTO glass prepared by Doctor's blade method, respectively. © 2014 Elsevier B.V. All rights reserved.
Mollaamin F.,Islamic Azad University at Qom
Journal of Computational and Theoretical Nanoscience | Year: 2014
A Nano biofuel cell employing a Boron nitride nanotube (BNNT) and flavin adenine dinucleotide (FAD) based on the direct electron transfer principle has been investigated using HF and DFT theoretical methods. FAD was immobilized on the BNNT together by combining water molecules in box model. We have performed the quantum chemical model to evaluate the effect of BNNT in direction of electron transfer, stability, electric properties including resistance, voltage, current, conductivity, limiting conductivity, power and nuclear magnetic resonance parameters and thermochemical properties as a biofuel cell. The data exhibited that the BNNT biofuel cell model can be applied for generating electric power in lower resistances with the best agreement in linear correlation of voltage-current directly from sustainable fuel substrate such as FAD. In this paper, the results illustrated that together with the feasibility of using BNNT and FAD to become the norm in electrochemical bio system applications.Copyright © 2014 American Scientific Publishers Copyright © 2014 American Scientific Publishers.
Najafi G.R.,Islamic Azad University at Qom
Chinese Chemical Letters | Year: 2010
Primary and secondary benzylic alcohols were oxidized to the corresponding carbonyl compounds in good to high yields by environmentally friendly and green oxidant, H2O2 catalyzed by Montmorillonite-K10 supported manganese(II) chloride. © 2010 Gholam Reza Najafi.
Sharif M.A.,Islamic Azad University at Qom |
Najafi G.R.,Islamic Azad University at Qom
Acta Chimica Slovenica | Year: 2013
[Cd(C7H3NO4)(H2O)1.5] n or [Cd(2,6-pydc)(H2O)1.5] n, (1) (2,6-pydc = pyridine-2,6-dicarboxylate) was obtained from the reaction of pyridine-2,6-dicarboxylic acid and 4-hydroxypyridine-2,6-dicarboxylic acid with cadmium(II) nitrate tetrahydrate in the presence of piperazine and characterized by elemental analysis, IR spectra and X-ray single crystal diffraction. Complex (1) is a novel carboxylate-bridged one-dimensional pincer-shaped helical chain of cadmium(II) polymer. Each Cd atom is seven-coordinate and exhibits an approximately pentagonal-bipyramidal CdNO6 coordination geometry. The metal fragments are linked via the central four-membered Cd2O2 ring and the structural analysis showed that 4-hydroxypyridine-2,6-dicarboxylic acid and piperazine do not appear in the structure.
Farahani F.,Islamic Azad University at Qom
Plant Archives | Year: 2014
Although, several pineapple micropropagation protocols have already been published, significant improvement could be achieved, if the stages of in vitro culture were better defined. Our work concerned several experiments aiming at the mass production of high quality plantlets. Tissue culture experiments were therefore conducted to develop rapid multiplication procedures for Ananas comosus L. (Merr). Terminal buds from suckers were treated with 0.025% (w/v) mercuric chloride for 2 minutes and placed in different media. Explants were transferred to MS medium supplemented with NAA (2 mgl-1) and BA (0, 1, 2, 3, 4, 5, 6, 7 mgl-1) and kept for 2-4 months under 16/8 h photoperiod (40 μmol m-2 s-1) and 25 plusmn; 2°C. Results showed that higher multiplication rates for Ananas comosus L. were obtained with BA concentrations of 5 mgl-1 at 3 months. The in vitro proliferated shoots produced roots with maximum frequency (84%) on MS medium without growth regulator at 6 weeks intervals. Using the protocol described in this work, it is possible to obtain 1 million rooted plantlets after 12 months from a single bud, with a 45 day subculture interval.