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Yasmen M. Moghazy Magda F. Fathalla Nagwa M. M. Hamada Yasser R. Elmarassi Ezzat A. Hamed 《国际化学动力学杂志》2020,52(5):341-355
Reactions of aniline derivatives in dimethyl sulfoxide with phenyl 1-(2,4-dinitronaphthyl) ether yield aryl 1-(2,4-dinitronaphthyl) amine, which results in substitution of the phenoxy groups at the naphthyl ipso carbon atom. Rate constants were measured spectrophotometrically, and reaction proton transfer was rate limiting. The values of the rate coefficients indicate a rate-limiting proton transfer mechanism with significant substituent effects. The calculated activation parameters were of regular variation with substituents in 4- and 3-position in the aniline nucleophile, and the reaction proceeded through a common mechanism. Hammett's reaction constant showed that the reaction rate constants depend on the electron density of the nitrogen atom of aniline derivative, whereas the coefficient value obtained from the Brönsted relation indicated that the reaction was significantly associative and quite zwitterion like. Computational studies of the substitution were carried out based on density functional theory, and theoretical to the experimental agreement was achieved. 相似文献
23.
Mostafa M. Hamed 《Journal of Radioanalytical and Nuclear Chemistry》2014,300(1):303-313
In nuclear power plants and nuclear laboratories, laundry wastewater is generated from decontaminating polluted instruments, worker’s clothes and taking shower after work. Laundry wastewater contains radionuclides and surfactants. The surfactants included in laundry wastewater affect the extraction of radionuclides. Therefore, surfactants should be removed before extraction of radionuclides. The objective of the present work is to assess the ability of commercial charcoal for the removal of nonionic surfactants, where, commercial charcoal is a commonly available adsorbent for treatment. Charcoal was characterized using different analytical techniques. The isotherm models and thermodynamic parameters were evaluated. Charcoal was applied to the removal of surfactant from liquid radioactive waste. The data obtained can be used for designing a plant for treatment of surfactant rich water and wastewater economically. 相似文献
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Abdel-Kader Maged Saad Alam Prawez Alqarni Mohammed Hamed Salkini Mohamad Ayman 《平面色谱法杂志一现代薄层色谱法》2017,30(3):211-215
JPC – Journal of Planar Chromatography – Modern TLC - A novel, simple, and sensitive high-performance thin-layer chromatography (HPTLC) method has been successfully developed and... 相似文献
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Hadi Amiri Amir Charkhi Mohammad Ali Moosavian Seyyed Javad Ahmadi Hamed Nourian 《Chemical Papers》2017,71(9):1587-1596
The polydimethylsiloxane (PDMS) mixed matrix membrane with dispersed phase of nanozeolite silicalite-1 has been synthesized on polyethersulphone (PES) as a support, and its performance in the gas separation of xenon and krypton has been studied. For this purpose, nanozeolite silicalite-1 is synthesized by the hydrothermal clear solution method and is characterized by XRD and SEM analysis. In this research, the separation performance of MMM has also been compared with the polymeric PDMS membrane. Furthermore, the effect of feed pressure and loading percentage of nanozeolite in the polymeric matrix are evaluated. The results indicate that the addition of nanozeolite to the polymeric matrix improves its separation performance, and that the changes of the feed pressure have no major effect. The average permeability of the krypton and xenon gases through the PDMS polymeric membrane is calculated as 1.25 × 10?9 and 1.78 × 10?9 cm mol/(cm2 s kPa), respectively, while by adding only 5 wt% of nanosilicalite-1 to the polymeric matrix of the membrane, this amount increased to 1.82 × 10?9 and 8.07 × 10?9 cm mol/(cm2 s kPa), respectively. In addition, the presence of nanosilicalite-1 as the filler leads to an increase in the selectivity of xenon to krypton up to 4.38. 相似文献
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Mohammad Mehdi Rashidi Hamed Shahmohamadi 《Communications in Nonlinear Science & Numerical Simulation》2009,14(7):2999-3006
In this letter, we will consider variational iteration method (VIM) and Padé approximant, for finding analytical solutions of three-dimensional viscous flow near an infinite rotating disk. The solutions is compared with the numerical (fourth-order Runge–Kutta) solution. The results illustrate that VIM–Padé is an appropriate method in solving the systems of nonlinear equations. It is predicted that VIM–Padé can have wide application in engineering problems (especially for boundary-layer and natural convection problems). 相似文献
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Issa Yavari Abdolali Alizadeh Hamed Mohebbi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1741-1746
The reactive 1:1 intermediate produced in the addition reaction between trimethyl-phosphite and dibenzoylacetylene was trapped by SH- or NH-acids such as 4-nitroimidazole, 4-methyl-5-nitroimidazole, succinimide, or mercaptoacetic acid to produce 2-substituted 1,4-diphenylbutane-1,4-diones. 相似文献
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Abbas Afkhami Farzaneh Soltani-Felehgari Tayyebeh Madrakian Hamed Ghaedi Majid Rezaeivala 《Analytica chimica acta》2013
A new chemically modified carbon paste electrode was constructed and used for rapid, simple, accurate, selective and highly sensitive simultaneous determination of cadmium, copper and mercury using square wave anodic stripping voltammetry (SWASV). The carbon paste electrode was modified by N,N′-bis(3-(2-thenylidenimino)propyl)piperazine coated silica nanoparticles. Compared with carbon paste electrode, the stripping peak currents had a significant increase at the modified electrode. Under the optimized conditions (deposition potential, −1.100 V vs. Ag/AgCl; deposition time, 60 s; resting time, 10 s; SW frequency, 25 Hz; pulse amplitude, 0.15 V; dc voltage step height, 4.4 mV), the detection limit was 0.3, 0.1 and 0.05 ng mL−1 for the determination of Cd2+, Cu2+ and Hg2+, respectively. The complexation reaction of the ligand with several metal cations in methanol was studied and the stability constants of the complexes were obtained. The effects of different cations and anions on the simultaneous determination of metal ions were studied and it was found that the electrode is highly selective for the simultaneous determination of Cd2+, Cu2+ and Hg2+. Furthermore, the present method was applied to the determination of Cd2+, Cu2+ and Hg2+ in water and some foodstuff samples. 相似文献
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