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41.
Farhad Ahmadi Maryam Rajabi Forozan Faizi Mehdi Rahimi-Nasrabadi Bozorgmehr Maddah 《International journal of environmental analytical chemistry》2013,93(11):1123-1138
Fe3O4-SiO2-C18 paramagnetic nanoparticles have been synthesised and used as magnetic solid-phase extraction (MSPE) sorbent for the extraction of Zineb from agricultural aqueous samples under ultrasonic condition and quantified through a first-derivative spectrophotometric method. The produced magnetic nanoparticles were characterised by using scanning electron microscopy, X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy and zeta potential reader. The Fe3O4-SiO2-C18 paramagnetic nanoparticles had spherical structures with diameters in the range of 198–201 nm. Further, MSPE was performed by dispersion of Fe3O4-SiO2-C18 paramagnetic nanoparticles in a buffered aqueous solution accompanied by sonication. Next, the sorbents were accumulated by applying an external magnetic field and were washed with 4-(2-pyridylazo) resorcinol-dimethyl sulfoxide solution, for the purpose of desorbing the analyte. The extraction conditions (sample pH, washing and elution solutions, amount of sorbents, time of extraction, sample volume and effect of diverse ions), as well as Zineb-PAR first-order derivative spectra, were also evaluated. The calibration curve of the method was linear in the concentration range of 0.055–24.3 mg L?1 with a correlation coefficient of 0.991. The limit of detection and limit of quantification values were 0.022 and 0.055 mg L?1, respectively. The precision of the method for 0.27 mg L?1 solution of the analyte was found to be less than 3.2%. The recoveries of three different concentrations (0.27, 1.37 and 13.7 mg L?1) obtained 98.3%, 98.5% and 96.0%, respectively. The proposed Fe3O4-SiO2-C18 paramagnetic nanoparticles were found to have the capability of reusing for 7.0 times. 相似文献
42.
Synthesis and computational study of two new glycoluril clips containing benzocrown ether side walls
Esmail Rezaei-Seresht Sirous Salemi Mahnaz Ahmadi Sara Taghizadeh 《Journal of inclusion phenomena and macrocyclic chemistry》2013,76(1-2):69-74
Two new glycoluril-derived molecular clips containing benzocrown ether side walls have been synthesized via reaction of a glycoluril scaffold with two bromomethylated benzocrown ethers. The molecular geometry of their most stable structures were investigated with density functional theory at the B3LYP level of theory using STO-3G, 6-31G, and 6-311G basis sets. Then based on the obtained computer-optimized structures, the binding properties of one clip with some 5-substituted resorcinols have been calculated. 相似文献
43.
Mohammad-Ali Ahmadi Seyed Reza Shadizadeh 《Journal of Dispersion Science and Technology》2014,35(11):1537-1542
More than 50% of oil is trapped in petroleum reservoirs after applying primary and secondary recovery methods for removal. Thus, to produce more crude oils from these reservoirs, different enhanced oil recovery (EOR) approaches should be performed. In this research, the effect of hydrophilic nanoparticles of SiO2 at 12 nm size, in (EOR) from carbonate reservoir is systematically investigated. Using this nanoparticle, we can increase viscosity of the injection fluid and then lower the mobility ratio between oil and nanofluid in carbonate reservoirs. To this end, a core flooding apparatus was used to determine the effectiveness and robustness of nanosilica for EOR from carbonate reservoirs. These experiments are applied on the reservoir carbonate core samples, which are saturated with brine and oil that was injected with nanoparticles of SiO2 at various concentrations. The output results depict that, with increasing nanoparticle concentration, the viscosity of the injection fluid increases and results in decreased mobility ratio between oil and nanofluid. The results confirm that using the nanoparticle increases the recovery. Also, increasing the nanoparticle concentration up to 0.6% increases the ultimate recovery (%OOIP), but a further increase to 1.0 does not have a significant effect. 相似文献
44.
Soraia Meghdadi Mehdi Amirnasr Maryam Bagheri Fatemeh Ahmadi Najafabadi Kurt Mereiter Kurt Joß Schenk Fahimeh Ziaee 《Journal of the Iranian Chemical Society》2014,11(4):985-991
Nickel(II) and copper(II) complexes of two unsymmetrical tetradentate Schiff base ligands [Ni(Me-salabza)] (1), [Cu(Me-salabza)] (2) and [Ni(salabza)] (3), {H2salabza = N,N′-bis[(salicylidene)-2-aminobenzylamine] and H2Me-salabza = N,N′-bis[(methylsalicylidene)-2-aminobenzylamine]}, have been synthesized and characterized by elemental analysis and spectroscopic methods. The crystal structures of 2 and 3 complexes have been determined by single crystal X-ray diffraction. Both copper(II) and nickel(II) ions adopt a distorted square planar geometry in [Cu(Me-salabza)] and [Ni(salabza)] complexes. The cyclic voltammetric studies of these complexes in dichloromethane indicate the electronic effects of the methyl groups on redox potential. 相似文献
45.
Tayyebeh Madrakian Abbas Afkhami Nahid Rezvani-jalal Mazaher Ahmadi 《Journal of the Iranian Chemical Society》2014,11(2):489-498
The potential removal and preconcentration of lead(II), cadmium(II), and chromium(III) ions from wastewaters were investigated and explored. Magnetite nanoparticles were chemically modified with p-nitro aniline. The aniline-coated magnetite nanoparticles (ANMNPs) were fully characterized by FT-IR, XRD, SEM, and TEM measurements. Batch studies were performed to address various experimental parameters for the removal and determination of these ions. ANMNPs showed high tendency to investigated metal ions, in this order: Cr(III) > Cd(II) > Pb(II), owing to the strong contribution of surface loaded aniline. The potential applications of ANMNPs adsorbent for removal and preconcentration of Pb(II), Cr(III), and Cd(II) from wastewaters as well as drinking tap water samples were successfully accomplished giving recovery values of (98–101 %), without any noticeable interference of the wastewater or drinking tap water matrices. 相似文献
46.
Shiva Tavakoli Sayed Ali Ahmadi Dadkhoda Ghazanfari Enayatollah Sheikhhosseini 《印度化学会志》2022,99(7):100561
In recent years, fullerene nanoparticles have received extensive attention due to their unique physical and chemical properties. Properly modified fullerene nanoparticles have excellent biocompatibility and significant anti-tumor activity and anti-depression, which makes them have broad application prospects in the field of cancer anti-depression. The present study used the density functional theory (DFT) calculations to perform a theoretical examination of the interaction of fluoxetine (F) as medicine with the functionalized fullerene O and NO (F–O and F–NO surface in gas phase physiological media. According to DFT calculations, adsorption energies were ?3396.6350645, ?3540.2952907, ?6778.526894, and ?6952.251487 kJ for F/P complexes (fullerene O and NO (F–O and F–NO surface) respectively, proposing the possibility of the adsorption process of F molecule onto the fullerene surface concerning the energetic perspective. Calculations of electronic parameters aimed at determining the molecule's reactivity. Bandgap of F–O and F–NO were 0.03715, 0.04328 respectively, by this value we can recognize the reactivity of complexes. 相似文献
47.
Kumar Ravinder Ahmadi Mohammad H. Rajak Dipen Kumar 《Journal of Thermal Analysis and Calorimetry》2021,145(5):2625-2631
Journal of Thermal Analysis and Calorimetry - The present paper deals with the economic viability of a coal-fired power plant (CFPP) situated in the northern part of India. The plant with a... 相似文献
48.
Fatemeh Saghatchi Ebrahim Ahmadi Zahra Mohamadnia Hassan Hajifatheali Hashem Tabebordbar Farnoosh Karimi 《Chemical Papers》2014,68(11):1555-1560
This study is aimed at atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) using a novel catalyst. The bis-(2-dodecylsulfanyl-ethyl)-amine (SNS) tridentate ligand with mixed donor atoms was synthesized in high purity using inexpensive reagents and was reacted with copper(I) bromide to produce the CuBr/SNS catalyst. The catalyst mediated living polymerization of MMA yielding polymers with controlled molecular masses and narrow molecular mass distributions (PDI < 1.25). Also, the kinetic plot exhibited a linear increase of ln([M]0/[M]) versus time, indicating constant concentration of propagating radicals during the polymerization. The products were characterized by 1H NMR, 13C NMR, FT-IR, UV-VIS, GC and elemental analyses (CHNS) and by GPC. 相似文献
49.
50.
Three‐dimensional (3D) printing becomes an attractive technique to fabricate tissue engineering scaffolds through its high control on fabrication and repeatability using the printing parameters. This technique can be combined by the finite element method (FEM), and tissue‐specific scaffolds with desirable morphological and mechanical properties can be designed and manufactured. In this study, the influential 3D printing parameters on the morphological and mechanical properties of polycaprolactone (PCL) filament and scaffold were studied experimentally and numerically. First, the effects of printing parameters and process on the properties of extruded PCL filament were investigated. Then, using FEM, the effects of filament specifications on the overall characteristics of the scaffold were evaluated. Results showed that both the printing process in terms of resting time and remaining time and the printing parameters like pressure, printing speed, and printing path length have influenced the filament properties. In addition, both the filament diameter and elastic modulus had significant effects on the properties of scaffold especially, a 20% increase in the filament diameter caused the scaffold compressive elastic modulus to rise by around 72%. It is concluded that the printing parameters and process must be tuned very well in fabricating scaffolds with the desired morphology and mechanical property. 相似文献