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111.
Omid Jahanmahin Mohammad Mehdi Montazer Rahmati Toraj Mohammadi Jaber Babaee Arash Khosravi 《Chemical Papers》2016,70(7):913-925
In this study, a novel flat-type synergic-supported liquid membrane was evaluated with a mixture of N-methyl-N,N,N-trioctylammonium chloride (Aliquat 336) and tributyl phosphate (TBP) as the carrier and kerosene as the diluent to remove Cr(VI) from synthetic waste water. The main parameters involved in the process were identified and optimised. The parameters were divided into two groups, those that were independent and those having an interaction. The parameters of the carrier/kerosene volumetric proportion and stirring rate were optimised individually due to their nature. The optimal values of these parameters were 0.5 and 500 min?1, respectively, for a constant carrier/kerosene ratio and stirring rate in the designed experiments using the response surface method (RSM). The four parameters of TBP/Aliquat 336, chromium concentration in the feed phase, feed and product pH were optimised using RSM; it was observed that the TBP/Aliquat 336 ratio, feed pH, pH of the stripping phase and interaction of this parameter with feed concentration have the most important effects on the removal of Cr(VI). The optimal levels of these parameters were 0.61, 71.75 mg L?1, 3.5 and 12.66 for the ratio of TBP/Aliquat 336, feed chromium concentration, pH of the feed and pH of the product, respectively. An experimental removal rate of 94.63 % at the optimized levels was obtained. 相似文献
112.
Morteza Afshar Alireza Badiei Hamed Eskandarloo Ghodsi Mohammadi Ziarani 《Research on Chemical Intermediates》2016,42(10):7269-7284
Charge separation plays a key role in the conversion of solar energy into chemical energy for use in the redox reaction and as well as in the photocatalytic activity. In this study, SrTiO3 particles with different morphologies including irregular, tetrahexahedron, and cube were synthesized by an in situ solvothermal method. The photocatalytic activity of the synthesized nanoparticles was investigated in the photocatalytic decomposition of methylene blue under UV light irradiation. Tetrahexahedron SrTiO3 particles exhibited high decomposition activity (70 %), which is about two times higher than those of the irregular and cubic SrTiO3 particles. The high decomposition activity of tetrahexahedron SrTiO3 particles could be attributed to the improvement of charge separation achieved on different crystal facets. To reach a good charge separation, tetrahexahedron SrTiO3/TiO2 coupled nanoparticles were fabricated by impregnation method. Results showed that coupling tetrahexahedron SrTiO3 with TiO2 could produce efficient charge separation between tetrahexahedron SrTiO3 and TiO2 due to their matched band edges. In order to achieve better charge separation, the tetrahexahedron SrTiO3/90 %TiO2 sample was calcined at different temperatures in the 450–750 °C range. Tetrahexahedron SrTiO3/90 %TiO2 coupled nanoparticles calcined at 650 °C show high photocatalytic activity compared with other samples. The prepared samples were characterized by using various techniques such as X-ray diffraction, scanning electron microscopy, photoluminescence emission spectra, and UV–Vis diffuse reflectance spectroscopy. 相似文献
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In the present study, for the first time electromembrane extraction followed by high performance liquid chromatography coupled with ultraviolet detection was optimized and validated for quantification of four gonadotropin‐releasing hormone agonist anticancer peptides (alarelin, leuprolide, buserelin and triptorelin) in biological and aqueous samples. The parameters influencing electromigration were investigated and optimized. The membrane consists 95% of 1‐octanol and 5% di‐(2‐ethylhexyl)‐phosphate immobilized in the pores of a hollow fiber. A 20 V electrical field was applied to make the analytes migrate from sample solution with pH 7.0, through the supported liquid membrane into an acidic acceptor solution with pH 1.0 which was located inside the lumen of hollow fiber. Extraction recoveries in the range of 49 and 71% within 15 min extraction time were obtained in different biological matrices which resulted in preconcentration factors in the range of 82–118 and satisfactory repeatability (7.1 < RSD% < 19.8). The method offers good linearity (2.0–1000 ng/mL) with estimation of regression coefficient higher than 0.998. The procedure allows very low detection and quantitation limits of 0.2 and 0.6 ng/mL, respectively. Finally, it was applied to determination and quantification of peptides in human plasma and wastewater samples and satisfactory results were yielded. 相似文献
116.
The role of molecularly imprinted polymers (MIPs) is changing from academic to applied researches. Challenging problems about MIP will be more highlighted in applicable uses and solving these problems is vital. The controlled/“living” radical polymerization (CLRP) techniques are applicable to solve the challenging problems in MIPs. The “living” nature of CLRP helps to improve the heterogeneity of binding sites in MIPs as a main challenge where precise control over sizes, compositions, and surface functionalities is achieved. Among different techniques of CLRP, reversible addition-fragmentation chain transfer (RAFT) technique presents distinguished benefits such as compatibility and tolerance to a wide range of functional monomers and mild reaction conditions rather than other CLRP techniques. In this review, in order to obtain more insights into the potential benefits of RAFT polymerization in fabrication of nano and micro MIP networks, recent research in advanced MIP materials for different templates with improved morphology, efficiency, and binding capacities with respect to traditional free radical polymerization (FRP) will be discussed. MIPs prepared via RAFT method have advantages of MIPs as high performance molecular recognition devices and CLRP as controllable polymerization mechanism, simultaneously. 相似文献
117.
A modified glassy carbon electrode has been constructed using a 1-benzyl-4-ferrocenyl-1H-[1,2,3]-triazole along with multiwalled carbon nanotubes. The electrochemical behaviour of modified electrode has been investigated by cyclic voltammetry. Electrocatalytic activity of the modified electrode was investigated for the oxidation of hydroxylamine in 0.1 M phosphate-buffered solution of pH 8. The modified electrode showed electrocatalytic response to the oxidation of hydroxylamine at the potential of 330 mV. The linear range and detection limit for the detection of hydroxylamine in the optimum condition were found to be 4.0?×?10?7 to 6.75?×?10?4 M and 28.0?±?1.0 nM, respectively. Finally, the method was employed for the determination of hydroxylamine in water samples. 相似文献
118.
Three new ideas for anisotropic adaption of unstructured triangular grids are presented, with particular emphasis on fluid flow computations. © 1997 John Wiley & Sons, Ltd. 相似文献
119.
Bijan Mohammadi 《国际流体数值方法杂志》1997,25(2):183-203
A new approach for optimal shape design is introduced. The main ingredients are an unstructured CAD-free framework for geometry deformation and automatic differentiation (AD) in reverse mode. Transonic inviscid and viscous turbulent flows are investigated. Both two- and three- dimensional configurations are considered. These cases involve up to several thousand control parameters. © 1997 John Wiley & Sons, Ltd. 相似文献
120.
Sheikhahmadi Haidar Mohammadi Abolhassan Aghamohammadi Ali Harko Tiberiu Herrera Ramón Corda Christian Abebe Amare Saaidi Khaled 《The European Physical Journal C - Particles and Fields》2019,79(12):1-10
The European Physical Journal C - We study the Yukawa model with one scalar and one axial scalar fields, coupled to N copies of Dirac fermions, in curved spacetime background. The theory possesses... 相似文献