Entity

Time filter

Source Type


Ahmadian F.,Islamic Azad University at Shahreza
Journal of Alloys and Compounds | Year: 2013

Electronic structure calculations based on density functional (DFT) theory within the generalized gradient approximation (GGA) for the Ti2CoSn Heusler compound have been performed using the self-consistent full-potential linearized augmented plane wave (FPLAPW) method. The Ti2CoSn Heusler alloy was predicted to be a complete half-metal. The total magnetic moment of Ti2CoSn was obtained 3μB per formula unit for the equilibrium lattice parameter which is in agreement with Slater-Pauling rule Mtot = Ztot-18. The minority spin and spin-flip gaps were calculated equal to 0.87 eV and 0.47 eV, respectively. The spin-orbit interaction has a negligible contribution to the half-metallic and magnetic properties of Ti2-CoSb alloy. In addition, the band structure and density of states (DOSs) were studied and the origin of minority band gap was also discussed. The Ti2CoSn Heusler alloy maintains the half-metallic characteristic for lattice constants between 5.68 and 7.02 Å leading to be an interesting material in the field of spintronics. © 2013 Elsevier B.V. All rights reserved. Source


Nezamzadeh-Ejhieh A.,Islamic Azad University at Shahreza | Moazzeni N.,Islamic Azad University at Shahreza
Journal of Industrial and Engineering Chemistry | Year: 2013

Photocatalytic activity of CuS incorporated into an Iranian clinoptilolite (CuS-Cp) was studied for decolorization of a mixture of Methyl Orange and Bromocresol Green under sunlight irradiation. All samples were characterized by XRD, FTIR, DRS and TG/DTG techniques. The effect of some key experimental parameters such as: amount of the catalyst (0.05-5gL-1), initial concentration of dyes (5-30mgL-1), solution pH (1-11) and also dosage of H2O2 and KBrO3 was studied on the decolorization extent. The extent of decolorization was estimated from the residual concentration by spectrophotometrically and it was confirmed by the reduction of chemical oxygen demand (COD). © 2013 The Korean Society of Industrial and Engineering Chemistry. Source


Nezamzadeh-Ejhieh A.,Islamic Azad University at Shahreza | Amiri M.,Islamic Azad University at Shahreza
Powder Technology | Year: 2013

CuO as a semiconductor as incorporated onto an Iranian natural Clinoptilolite zeolite, was prepared by calcination of Cu(II)-ion exchanged Clinoptilolite. The obtained composite was used as a photocatalyst to degrade a p-aminophenol aqueous solution. All raw and modified samples were characterized using XRD, FT-IR, BET and SEM methods. The degradation and mineralization extents were performed by UV-vis spectrophotometry, COD and HPLC. The optimum values of the experimental parameters which affect the degradation efficiency were obtained as: 2.0gL-1 of the photocatalyst, 20ppm of p-aminophenol and pH 6.0. Hydrogen peroxide and potassium bromate considerably increased the rate of degradation. Zeolite bed had considerable role in the photodegradation efficiency, so the proposed catalyst significantly increased the efficiency with respect to CuO and especially Clinoptilolite alone. © 2012 Elsevier B.V. Source


Nezamzadeh-Ejhieh A.,Islamic Azad University at Shahreza | Kabiri-Samani M.,Islamic Azad University at Shahreza
Journal of Hazardous Materials | Year: 2013

In this work an Iranian natural clinoptilolite tuff was pre-treated and changed to the micro (MCP) and nano (NCP) particles by mechanical method. Modification of micro and nano particles and also their Ni-exchanged forms were done by dimethylglyoxime (DMG). The raw and modified samples were characterized by XRD, FT-IR, SEM, BET, TG-DTG and energy dispersive analysis X-ray spectroscopy (EDAX). Removal of Ni(II) by modified and unmodified samples was investigated in batch procedure. It was found that NCP-DMG has higher capacity for removal of Ni(II). The effects of analytical parameters such as pH, dose of DMG, concentration of nickel solution, contact time and selectivity were studied and the optimal operation parameters were found as follows: pHPZC: 7.6, CNi(II): 0.01M, contact time: 360min and DMG dosage: 5mM. The results of selectivity experiments showed that the modified zeolite has a good selectivity for nickel in the presence of different multivalent cations. Langmuir and Freundlich isotherm models were adopted to describe the adsorption isotherms. Adsorption isotherms of Ni(II) ions could be best modelled by Langmuir equation, that indicate the monolayer sorption of Ni(II). Comparison of two kinetic models indicates that the adsorption kinetic can be well described by the pseudo-second-order rate equation that indicates that the rate limiting step for the process involves chemical reaction. The negative δH and δG indicate an exothermic and spontaneously process. The negative δS indicates that the adsorption of nickel cations from solution occurs with lower amount ion replacement, thus chemisorptions due to complex formation are dominant process in nickel removal. © 2013 Elsevier B.V. Source


Mokhtari B.,Islamic Azad University at Shahreza | Pourabdollah K.,Islamic Azad University at Shahreza
Journal of the Electrochemical Society | Year: 2012

Four proton di-ionizable diacid conformers of cone 25,27-di(carboxymethoxy) calix4arene-crown-5, 1,3-alternate 25,27-dicarboxymethoxy-calix4arene-crown-5, cone 25,27-biscarboxymethoxycalix4arene-crown-6 and 1,3-alternate 25,27-dicarboxymethoxy-calix4arene-crown-6 were synthesized and their binding abilities toward alkali and alkaline earth metals as well as some lanthanides were studied by means of differential pulse voltammetry. The novelty of this study was investigation of those nano-baskets by voltammetric behavior of two acidic moieties in each scaffold during complexation of the crown ether ring. Their voltammetric behavior was closely related to the complex formation by entrapment of the cation into the crown ether cavity and ion-dipole interaction between cation and acidic moieties in calixcrowns. The results revealed the selective changes in voltammetric behavior of synthesized scaffolds toward the cations. Moreover, the position of crown ether in 1,3-alternate instead of cone enhanced the domain of binding ability to more cations. Furthermore, it was shown that those carboxylic acid moieties, which were far from the crown ether ring in the 1,3-alternate, were not affected by encapsulated cations in the coordination space of crown ether and showed no voltammetric response. © 2011 The Electrochemical Society. Source

Discover hidden collaborations