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131.
Albayari Mohammad Nazal Mazen K. Khalili Fawwaz I. Nordin Norazzizi Adnan Rohana 《Journal of Radioanalytical and Nuclear Chemistry》2021,328(2):669-678
Journal of Radioanalytical and Nuclear Chemistry - In recent years, biochar based adsorbents have been given more attention for organic and inorganic pollutants removal. Therefore, in this study, a... 相似文献
132.
Synthesis, antibacterial, antifungal and antiviral activity evaluation of some new bis-Schiff bases of isatin and their derivatives 总被引:1,自引:0,他引:1
Jarrahpour A Khalili D De Clercq E Salmi C Brunel JM 《Molecules (Basel, Switzerland)》2007,12(8):1720-1730
Twelve new bis-Schiff bases of isatin, benzylisatin and 5-fluoroisatin 3a-3l were prepared by condensation of isatin, benzylisatin and 5-fluoroisatin with primary aromatic amines. The chemical structures of the products were confirmed by 1H- and 13CNMR, IR and mass spectral data. The compounds were screened for antiviral activity against a panel of DNA and RNA viruses. Minimum cytotoxic and minimum virus-inhibitory concentrations of these compounds were determined. Compounds 3c and 3i were the most cytotoxic in HEL cells. These newly synthesized bis-Schiff bases were also tested for their antibacterial and antifungal activities. They did not display activity against S. cerevisiae (ATCC 28383) or C. albicans (CIP 1180-79). 相似文献
133.
As one of the most recently developed membrane separation processes, nanofiltration (NF) has found a number of industrial applications. Ceramic NF membranes are also regarded as the appropriate choice in many applications, due to their higher chemical and physical stability. In this study, the rejection of the chloride ion is investigated using bi-layered γ-Al2O3-TiO2 NF membranes based on α-alumina supports. Compression is used in preparation of the supports and sol-gel dip-coating for the top-layer formation. SEM micrographs, XRD, and nitrogen adsorption/desorption isotherms are used for membrane characterisation. The results show that the calcination temperature (600°C) results in different crystal structures including the brookite phase of TiO2, the γ phase of Al2O3, and a combined phase of aluminium-titanium oxides. The average pore size of the membrane was identified as 1.6 nm using an adsorption/desorption isotherm. The rejection was also studied for the chloride ion, using a cross-flow filtration module. Filtration tests were carried out under different pressures, pH values, and salt concentrations; these showed a smoother behaviour particularly around the isoelectric points (IEPs) due to the dual-layer structure, with the best rejection at pH of approximately 5. 相似文献
134.
Mohammad Ali Rasouli Mohammad Mahdavi Mina Saeedi Parviz Rashidi Ranjbar Abbas Shafiee Alireza Foroumadi 《Journal of heterocyclic chemistry》2015,52(2):386-391
The present study provides an efficient strategy for the preparation of novel N‐substituted‐4‐methyl‐quinolin‐1(2H)‐one derivatives via two‐step Ugi/Heck reaction. The procedure is based on the Ugi coupling between 2‐bromoanilines, various aromatic aldehydes, vinylacetic acid, and isocyanides, and then intramolecular Heck reaction, which leads to the formation of the title compounds in good yields. 相似文献
135.
In this paper, a novel carbon nanotube field effect transistor with linear doping profile channel (LDC-CNTFET) is presented. The channel impurity concentration of the proposed structure is at maximum level at source side and linearly decreases toward zero at drain side. The simulation results show that the leakage current, on-off current ratio, subthreshold swing, drain induced barrier lowering, and voltage gain of the proposed structure improve in comparison with conventional CNTFET. Also, due to spreading the impurity throughout the channel region, the proposed structure has superior performance compared with a single halo CNTFET structure with equal saturation current. Design considerations show that the proposed structure enhances the device performance all over a wide range of channel lengths. 相似文献
136.
We report on a method for trace analysis of the narcotic drugs alfentanil, fentanyl, and sufentanil in plasma and urine. Two?Cphase hollow fiber liquid?Cphase microextraction was combined with GC using nitrogen?Cphosphorus detection. Experimental parameters were optimized to give a viable analytical procedure whose limits of detection range from 8 to 15?ng L?1 (at an S/N of 3). The calibration curves are linear between 0.1 and 50???g L?1, with squared correlation coefficients (r 2) between 0.9953 and 0.9979. Precision values range from 2.4% to 3.3% (intra?Cday RSD) and 3.2 to 6.3% (inter?Cday RSD). The relative recoveries varied from 27.8% to 84.6% (for spiked plasma) and 75 to 85.2% (for spiked urine). The method consumes little solvent, is simple, fast, inexpensive, and well suitable for the analysis of complicated matrices. Figure
Schematic diagram of two phase hollow fiber liquid-phase microextraction (HF-LPME) combined with GC and nitrogen?Cphosphorus detection for trace analysis of the narcotic drugs alfentanil, fentanyl, and sufentanil in plasma and urine. 相似文献
137.
The aim of this paper is to survey interlaboratory studies of performance data to produce highly permeable thin‐film composite (TFC) polyamide nanofiltration (NF) membrane in the form of flat sheet at bench scale. TFC polyamide NF membranes were fabricated via interfacial polymerization of 1,3‐phenylenediamine and trimesoyl chloride on porous polyethersulfone (PES) membrane. The NF membranes were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), and cross‐flow filtration. The AFM and SEM analyses indicated that a rough and dense film was formed on the PES support membrane. The permeability and NaCl rejection of the NF membrane prepared at the presence of camphor sulfonic acid as pH regulator and triethylamine as accelerator in the aqueous solution were 21 l m?2 h?1 and 70%, respectively. In order to estimate the repeatability and reproducibility standard deviations, the development of an interlaboratory study was conducted by measurements of permeation flux and salt rejection of the synthesized membranes. Repeatability standard deviation of the permeation flux data for the membrane based on optimum formulation was 1.99, and reproducibility standard deviation was 3.55. Also based on this trend, repeatability standard deviation of the salt rejection data was 1.57, and reproducibility standard deviation was 4.11. The American Society for Testing and Materials standard E691‐05 was used for data validation of the repeatability and reproducibility standard deviations and consistency statistics. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
138.
Badri Z Foroutan-Nejad C Rashidi-Ranjbar P 《Physical chemistry chemical physics : PCCP》2012,14(10):3471-3481
The influence of various all-electron basis sets and effective core potentials employed along with several DFT functionals (B3LYP, B3PW91, BLYP, BP86 and M06) on the magnitude of nucleus independent chemical shift (NICS) values in different metallic nano-clusters and hydrocarbons is studied. In general, it is demonstrated that the NICS values are very sensitive to the applied method/basis set; however, the method/basis set dependence is more prominent for computed NICS values in transition metal clusters. In hydrocarbons, medium-size basis sets perform roughly similar to large basis sets in most cases. It is also found that NICS(0) values are more sensitive to the method/basis set variation compared to the NICS values computed at 1 or 2 ? above the ring plane. However, in many cases, no broad-spectrum regulation is found for the effect of basis set/method on the magnitude of NICS values. A detailed study showed that bond length alternation in a molecule has an insignificant effect on the magnitude of NICS values so the influence of method/basis sets on the magnitude of NICS values mostly arises from the different predicted ring current intensities at various computational levels. 相似文献
139.
Humenny WJ Mitzinger S Khadka CB Najafabadi BK Vieira I Corrigan JF 《Dalton transactions (Cambridge, England : 2003)》2012,41(15):4413-4422
The ligation of a N-heterocyclic carbene (NHC) to group 11 metal salts (Cu, Ag) was explored as an alternative to PR(3) ligands for the formation of copper- and silver-chalcogenolate cluster complexes. AgOAc and CuCl salts ligate with the NHC 1,3-di-isopropylbenzimidazole-2-ylidene ((i)Pr(2)-bimy) forming [Ag(OAc)((i)Pr(2)-bimy)] 1, [Ag(OAc)((i)Pr(2)-bimy)(2)] 2, [CuCl((i)Pr(2)-bimy)](2)3 and [CuCl((i)Pr(2)-bimy)(2)] 4 depending on the ratio of ligand to metal used. These have been characterized via spectroscopic and crystallographic methods. Complexes 1 and 3 were reacted with S(Ph)SiMe(3) and Se(Ph)SiMe(3) to form the polynuclear metal-chalcogenolates [Ag(4)(μ-EPh)(4)((i)Pr(2)-bimy)(4)] (5, E = S; 6, E = Se) and [Cu(3)(μ-EPh)(3)((i)Pr(2)-bimy)(3)] (7, E = S; 8, E = Se) in good yields. The structures of 5-8, as determined by single crystal X-ray crystallography, are described. 相似文献
140.
Donya Rahmani Reza Ramezanian Parviz Fattahi Mahdi Heydari 《Applied Mathematical Modelling》2013,37(20-21):8957-8971
Production planning (PP) is one of the most important issues carried out in manufacturing environments which seeks efficient planning, scheduling and coordination of all production activities that optimizes the company’s objectives. In this paper, we studied a two-stage real world capacitated production system with lead time and setup decisions in which some parameters such as production costs and customer demand are uncertain. A robust optimization model is developed to formulate the problem in which minimization of the total costs including the setup costs, production costs, labor costs, inventory costs, and workforce changing costs is considered as performance measure. The robust approach is used to reduce the effects of fluctuations of the uncertain parameters with regards to all the possible future scenarios. A mixed-integer programming (MIP) model is developed to formulate the related robust production planning problem. In fact the robust proposed model is presented to generate an initial robust schedule. The performance of this schedule could be improved against of any possible occurrences of uncertain parameters. A case from an Iran refrigerator factory is studied and the characteristics of factory and its products are discussed. The computational results display the robustness and effectiveness of the model and highlight the importance of using robust optimization approach in generating more robust production plans in the uncertain environments. The tradeoff between solution robustness and model robustness is also analyzed. 相似文献