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排序方式: 共有559条查询结果,搜索用时 15 毫秒
21.
Mona Hosseini-Sarvari 《Catalysis Letters》2011,141(2):347-355
Abstract
An eco-friendly catalytic amount (10 mol%) of nanocrystalline ZnO has been explored in the synthesis of new series of ferrocenyl aminophosphonic esters by a three-component reaction of ferrocene carbaldehyde, an amine, and a dialkyl phosphate. The nano ZnO catalyzed the selective synthesis of ferrocenyl aminophosphonates and no intermediate formation of either an imines or α-hydroxy phosphonate were observed. This is one of the fundamental aspects in green chemistry for simple experimental and product isolation protocol. 相似文献22.
A new additive cationic surfactant for drilling fluid was synthesized by alkylation of coal tar phenol with tetradecyl alcohol;
then, the alkyl phenol reacts with formaldehyde and amine to produce the Mannich base product. This product was reacted with
sodium chloroacetate to produce the cationic surfactant; the structure of the synthesized surfactant was confirmed by FTIR
analysis, evaluation of the prepared surfactant by surface properties such as surface tension, emulsification power, and wetting
power. The prepared cationic surfactant showed good results when utilized in the formulation of both oil-based mud and synthetic-based
mud as the primary emulsifier. 相似文献
23.
An agriglass composition containing different oxides acts as a slow release for macro and micro nutrients and was chosen to improve maize yield under most important abiotic stresses which affecting agriculture development; salinity and drought. A field experiment was performed in salt affected soil (EC =?7.5 dSm??1) by using different water deficit rates (I1 = 100, I2 = 85 and I3 = 70% of maize water requirements). Irrigation levels were located in main plots. Every main-plot divided into six sub-plots contained glassy fertilizer treatments [F1 = 55 kg fed?1 with 1/2 mm diameter of agriglass (fed. =?4200 m2), F2 = 55 kg fed?1 with 1 mm diameter, F3 = 80 kg fed?1 with 1/2 mm diameter, F4 = 80 kg fed?1 with 1 mm diameter, F5 = Recommendations of Ministry of Agriculture and F6 = control]. The experimental results demonstrated that, ears, straw, grains and biological yields increased with increasing both water and agriglass rates. Application of agriglass as a slow release fertilizer improved yield more than mineral fertilizer. Some growth parameters, water use efficiency (IWUE), macronutrients concentration and their relations were included. Other studies on residual effect of agriglass and the annual application rates to withstand salinity and drought stress by strategic crops are required. 相似文献
24.
25.
Mohamed N. Aboul-Enein Aida A. El-Azzouny Mohamed I. Attia Yousreya A. Maklad Mona E. Aboutabl Fatma Ragab Walaa H. A. Abd El-Hamid 《International journal of molecular sciences》2014,15(9):16911-16935
Synthesis and anticonvulsant potential of certain new 6-aryl-9-substituted-6,9-diazaspiro[4.5]decane-8,10-diones (6a–l) and 1-aryl-4-substituted-1,4-diazaspiro[5.5]undecane-3,5-diones (6m–x) are reported. The intermediates 1-[(aryl)(cyanomethyl)amino]cycloalkanecarboxamides (3a–f) were prepared via adopting Strecker synthesis on the proper cycloalkanone followed by partial hydrolysis of the obtained nitrile functionality and subsequent N-cyanomethylation. Compounds 3a–f were subjected to complete nitrile hydrolysis to give the respective carboxylic acid derivatives 4a–f which were cyclized under mild conditions to give the spiro compounds 5a–f. Ultimately, compounds 5a–f were alkylated or aralkylated to give the target compounds 6a–i and 6m–u. On the other hand, compounds 6j–l and 6v–x were synthesized from the intermediates 5a–f through alkylation, dehydration and finally tetrazole ring formation. Anticonvulsant screening of the target compounds 6a–x revealed that compound 6g showed an ED50 of 0.0043 mmol/kg in the scPTZ screen, being about 14 and 214 fold more potent than the reference drugs, Phenobarbital (ED50 = 0.06 mmol/kg) and Ethosuximide (ED50 = 0.92 mmol/kg), respectively. Compound 6e exhibited an ED50 of 0.019 mmol/kg, being about 1.8 fold more potent than that of the reference drug, Diphenylhydantoin (ED50 = 0.034 mmol/kg) in the MES screen. Interestingly, all the test compounds 6a–x did not show any minimal motor impairment at the maximum administered dose in the neurotoxicity screen. 相似文献
26.
Mona Iravaninia Mojtaba Mirfendereski Toraj Mohammadi 《Chemical Engineering Research and Design》2012
In this work, separation of toluene/n-heptane mixtures via pervaporation using a composite membrane was investigated. Effects of operating conditions such as feed temperature, feed composition and downstream pressure on the membrane performance were studied. Experimental results were obtained at different feed compositions (10–40 wt.%), operating temperatures (25–85 °C) and downstream pressures (2–32 mbar g). The membrane selectivity for toluene was found to be greater than that for n-heptane. According to the results, it was observed that increasing toluene concentration in the feed and operating temperature enhance the membrane swelling and increase the polymeric chain mobility. Therefore, feed concentration and temperature have the same effects on toluene selectivity and permeation flux of the membrane. Permeation flux increases and toluene selectivity decreases with increasing feed concentration and temperature. In contrary, the membrane performance enhances with decreasing downstream pressure. It was found out that for a feed with 10 wt.% of toluene, at a temperature of 85 °C and a downstream pressure of 2 mbar g, the highest PSI value of 18.371 kg/m2 h (in which permeation flux = 4.610 kg/m2 h and toluene selectivity = 4.985) is achieved. 相似文献
27.
A detailed model was developed for emulsion polymerization of styrene in batch reactor to predict the evolution of the product particle size distribution. The effect of binary surfactant systems (ionic/non-ionic surfactants) with different compositions was studied. The zero–one kinetics was employed for the nucleation rate, with the model comprising a set of rigorously developed population balance equations. The modeling incorporated particle formation by both nucleation and coagulation phenomena. The partial differential equations describing the particle population were discretized using finite volume elements. Binary surfactant systems, comprising sodium dodecyl sulfate (SDS) as anionic, and a commercial polyether polyol (Brij35®) as non-ionic surfactants, were examined with different mass ratios. Increasing non-ionic surfactant mass fraction in binary surfactant system showed the decrease of particle number due to intensifying the coagulation between particles. Broader particle size distributions with greater average particle size were obtained with non-ionic surfactant comparing those obtained with anionic one. 相似文献
28.
Mahdi Mohammadi Ghaleni Elham Tavakoli Mona Bavarian Siamak Nejati 《American Institute of Chemical Engineers》2020,66(11):e17019
Membranes with asymmetric wettability-Janus membranes-have recently received considerable attention for a variety of critical applications. Here, we report on a simple approach to introduce asymmetric wettability into hydrophilic porous domains. Our approach is based on the physicochemical-selective deposition of polytetrafluoroethylene (PTFE) on hydrophilic polymeric substrates. To achieve selective deposition of PTFE, we inhibit the polymerization reaction within the porous domain. We prefill the substrates with glycerol, containing a known amount of free radical inhibitor, and utilize initiated chemical vapor deposition (iCVD) for the polymerization of PTFE. We show that the glycerol/inhibitor mixture hinders the deposition of PTFE within the membrane pores. As a result, the surface of the substrates remains open and porous. The fabricated Janus membranes show stable wetting-resistant properties, evaluated through sessile drop contact angle measurements and direct contact membrane distillation (DCMD). 相似文献
29.
Ahmed M. Awad Abouelata S. M. Aly Abdallah Mohamed H. Sorour Nourhan A. Shawky Mona A. Abdel-Fatah 《应用聚合物科学杂志》2020,137(39):49190
Hollow fiber membrane (HF) is considered one of the prevalent materials for water treatment; its effectiveness is controlled by permeation and mechanical characteristics. In this study, HF membrane surface was stimulated using electrochemical technique, where binary system of stainless steel cylinder and graphite rod electrodes was used into electrolytic solution of sodium acetate 0.1 M as electrolyte. Two pH of acidic medium (pH = 3.5) and alkaline medium (pH = 8.5) were prepared and different potential between 2 and 10 V were applied. EDX analysis of HF membrane surface revealed the formation of sodium ions on the surface of HF membrane with maximum content of Na+ ions 1.84%. Also, HF membrane surface showed variation of roughness (R a) as, HF membrane surface may undergo distortion by using aggressive conditions of high electric potential (7.5–10 V), The measured raw HF membrane (R a) was 34.8 nm, while, after electrochemical modification in alkaline medium R a showed higher values 36, 37, and 41 nm using 2, 2.5, and 5 V, respectively. While, after electrochemical modification in acidic medium (R a) showed 35, 39, 42, 49, 52 nm for 2, 2.5, 5, 7.5, and 10 V, respectively. Moreover, tensile strength Young's modulus, break stress and break strain were measured after electrochemical modification in both acidic and alkaline mediums and maximum porosity value 76.84% was observed after 30 min in acidic medium. 相似文献
30.
Dalia Heggo Shinichi Ookawara Teruhisa Ohno Toru Nakai Yoshihisa Matsushita Mona Gamal Eldin Masahiro Ohshima 《加拿大化工杂志》2020,98(1):119-126
Dense photocatalyst slurry was employed for the synthesis of p-anisaldehyde under solar light irradiation. An Fe-modified rutile TiO 2 (Fe-TiO 2, 34.5 m 2/g) photocatalyst was used as a visible-light-responsive photocatalyst. A conventional TiO 2 (P25, 35 m 2/g) photocatalyst was also examined as a reference catalyst. XRD patterns and diffuse reflectance spectra showed that Fe-TiO 2 consists of 100 % rutile phase and absorbs more visible light compared to P25, respectively. The catalyst powder was suspended in an ethyl acetate solution of p-methoxytoluene in the mini-reactor, with oxygen bubbling, under a solar simulator, visible light, and UV LEDs. p-anisaldehyde, as a reaction product, was analyzed by sampling using gas-chromatograph. Regardless of the light source, Fe-TiO 2 always outperformed P25 in terms of both generation rates (GR) of p-anisaldehyde and energy requirements (ER). It was demonstrated that the highly dense Fe-TiO 2 slurry was efficient for the synthesis under solar light owing to the small size of the reactor. The small amount of Pt and ZrO 2 cocatalysts significantly enhanced the GR under solar light. By adopting a visible light responsive Fe-TiO 2 photocatalyst, the mini slurry-bubble reactor under solar light achieved a high GR per catalyst mass (CM), which is one to two orders higher than that reported by most previous studies with high-power lamps. 相似文献