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151.
Friedel–Crafts sulfonylation of aromatic compounds was carried out using FeCl3-based ionic liquid. These liquids serve as efficient media as well as Lewis acid catalyst. 相似文献
152.
In this paper 1,3-dipolar cycloaddition reaction has been studied. An efficient synthesis of 4′-[3-methyl-5-thioxo-1H-1,2,4-triazol-4(5H)-yl]-2′,5′-diphenyl-2′,4′-dihydro spiro(indolin-3,3′[1,2,4]triazol)-2-one derivatives using triethylamine in MeCN at room temperature is reported. The structures of the obtained compounds were confirmed by means of elemental analysis, MS and spectral (IR, 1H, and 13C NMR) methods. 相似文献
153.
Milad Pero Mohammad Saeid Yarmand Vahid Samavati 《Journal of Dispersion Science and Technology》2014,35(2):215-222
A model low-fat salad dressing including salep as thickening agent was prepared. In order to obtain an stable salad dressing, different variables each one at three levels like salep content (0.5, 2.0, and 3.5% w/w), oil volume fraction (7.50, 16.25, and 25.00% w/w), pH (3, 5, and 7), salt concentration (0.3, 0.9, and 1.5% w/w), and egg yolk content (2, 4, and 6% w/w) were chosen and their effect on the creaming index of salad dressing was studied. It was observed that samples with highest salep content at pH 3 were the most stable during storage time (15 days). The microstructure of some samples was considered. Rheological measurements were performed for stable samples. Oil fraction and salt content increased zero shear viscosity and G′ modulus of samples. 相似文献
154.
Amir Hossein Haghighi Milad Sheydaei Ahmad Allahbakhsh Marzieh Ghatarband Fatemeh Sadat Hosseini 《Journal of Thermal Analysis and Calorimetry》2014,117(2):525-535
In this study, the influences of expanded graphite oxide (EG) nanosheets presence with and without surfactant on structural and thermal performance of poly(ethylene disulfide) (PEDS)-based nanocomposites are investigated. Sodium dodecylbenzenesulfonate (SDBS) is used as a surfactant for the preparation of modified-EG nanosheets. The structural, morphological, and thermal properties of prepared nanocomposites are studied using X-ray diffraction (XRD), scanning electron microscopy, and differential scanning calorimetry techniques, respectively. XRD patterns of nanocomposites reveal that a high degree of expanded graphite nanosheets dispersion is achieved with and without surface modification using in situ polymerization method. Moreover, the presence of immobilized polysulfide chains near the interface region of nanosheets is suggested as a possible reason for the observed increase in the number of semi-crystalline organic fractions in the structure of PEDS via EG nanosheets incorporation. In addition, the morphology of SDBS-modified-EG loaded nanocomposite shows a smoother fracture surface than unmodified-nanosheets reinforced nanocomposite. Therefore, more interactions between nanosheets and polysulfide chains are expected in the structure of unmodified-EG reinforced nanocomposite. Moreover, thermal resistance and degradation kinetics of prepared nanocomposites are studied using thermogravimetric analysis results and degradation activation energy calculations, respectively. The required activation energy for the degradation process of SDBS-EG loaded nanocomposite is about 140 kJ mol?1 lower than the required degradation activation energy of unmodified-nanosheets reinforced nanocomposite. 相似文献
155.
Magnetic nanoparticles (MNPs) can be used as heat generation source in cancer hyperthermia therapy. While iron oxide nanoparticles (NPs) are the most popular choice for magnetic hyperthermia, adding a surface enhancement can improve its performance. Furthermore, for MNPs to be used in biomedical application their cytotoxicity needs to be evaluated. In this study biocompatibility and also in vivo performance of casein‐coated MNPs were assessed. Cell viability of normal cell lines in all of tests remained above 95% for 0.5 and 1 mg/mL concentration and even the minimum recorded cell viability for normal cell lines was 84.78% at 20 mg/mL concentration. In contrast cell viability of cancer cell lines in contact with casein coated MNPs core‐shell structure except for one sample remained below 85%. By introduction of and alternating magnetic field, cell viability of samples with lower MNP concentration dropped by 20% to 30% while this drop for samples with higher concentration was 10% to 20%. Furthermore, results of in vivo trials show that just 1 week of hyperthermia treatment with casein coated MNPs core‐shell structure can reduce the tumor size of the mice by 33%. Real‐time polymerase chain reaction results further confirmed the effectiveness of this method. Moreover, findings of this study suggest that lower injection speed can improve NPs distribution and treatment effect. Results of this study suggest that core‐shell structure can positively affect the tumor growth and the combination of good biocompatibility, innate hostility toward cancer cells and good heating power makes them a good candidate for hyperthermia cancer therapy applications. 相似文献
156.
Fatemeh Sabermahani Mohammad Ali Taher Habibe Bahrami Zahra Hassani 《International journal of environmental analytical chemistry》2013,93(3):265-278
A column, solid phase extraction (SPE), preconcentration method was developed for determination of silver by using alumina coated with 1-((5-nitrofuran-2-yl)methylene)thiosemicarbazide and determination by flame atomic absorption spectrometry. The separation/preconcentration conditions for the quantitative recovery were investigated. At pH 2, the maximum sorption capacity of Ag+ was 7.5?mg?g?1. The linearity was maintained in the concentration range of 0.02–11.0?µg?mL?1 in the final solution or 0.14–1.10?×?104?ng?mL?1 in the original solution for silver. The preconcentration factor of 140 and relative standard deviation of ±1.4% was obtained, under optimum conditions. The limit of detection (LOD) was calculated as 0.112?ng?mL?1, based on 3σbl/m (n?=?8) in the original solutions. The proposed method was successfully applied to the determination trace amounts of silver in the environmental samples such as tea, rice and wheat flour, mint, and real water samples. 相似文献
157.
Pure and binary adsorption equilibrium data of ethylene and ethane on zeolite 5A were collected with a volumetric method for the temperature range 283 K to 323 K and pressure up to 950 kPa. The applicability of the binary adsorption prediction by the vacancy solution theory (VST) was investigated. Further individual adsorption and selectivity were obtained by VST prediction. According to the experimental results, zeolite 5A has a high adsorption capacity and selectivity for ethylene in the ethylene/ethane system. VST predicts that ethylene selectivity increases with pressure; it also shows that the amount of ethylene separated by zeolite 5A increases as the temperature decreases at a specified pressure. 相似文献
158.
The kinetics of the permanganic oxidation process of L ‐norleucine, L ‐leucine, L ‐iso‐leucine, and L ‐tert‐leucine in strong acid medium has been investigated using a spectrophotometric technique. Conclusive evidences have proven autocatalytic activity of Mn(II) for these reactions in strong acid medium analogous to weak acid medium, but in the former, ratio of Mn(II) to amino acid concentration must reach a certain amount for autocatalytic phenomenon to emerge, which we call “critical ratio.” This critical ratio depends on the nature of the amino acid employed. Thus considering “delayed autocatalytic behavior” of Mn(II) ions, rate equations satisfying observations for both catalytic and noncatalytic routes have been presented. Kinetic data in a noncatalytic pathway have been fitted to a biparametric equation including inductive, steric, and hyperconjugation correction effects, and it is determined that by shifting the side branch on a carbon chain toward an α‐carbon atom (adjacent to amino acid's functional group) and also adding branches to the α‐carbon atom, the reaction rate in the noncatalytic pathway decreases. Inductive and steric hindrance factors in amino acid's carbon chain are effective on processes' rate both in catalytic and noncatalytic pathways. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 38: 1–11, 2006 相似文献
159.
A series of novel polyfunctionalized acyclic and heterocyclic dye precursors and their respective azo (hydrazone) counterpart dyes and dye precursors based on conjugate enaminones and/or enaminonitrile moieties were synthesized. The dyes and their precursors are based on 2-cyano-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-acetamide, 2-ethoxycarbonyl-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-acetamide or 2-phenylcarbamoyl-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-acetamide systems as precursors. The latter compounds were used to synthesize polyfunctional thiophene-, thiazole-, pyrazole, pyridine-, pyrimidine-, oxazine-, as well as acyclic moieties. The dyes and dye precursors were characterized by elemental analysis and spectral methods. All dyes and their precursors were screened in vitro and evaluated for both their antibacterial and antifungal activities. MIC data of the novel dye systems and their respective precursors showed significant antimicrobial activity against most tested organisms. Some compounds exhibited comparable or even higher efficiency than selected standards. Dyes were applied at 5% depth for disperse dyeing of nylon, acetate and polyester fabrics. Their spectral characteristics and fastness properties were measured and evaluated. 相似文献
160.
Hojjat Nadi Mahdi Sadeghi Milad Enferadi Parvin Sarabadani 《Journal of Radioanalytical and Nuclear Chemistry》2011,289(2):361-365
In the present study, ytterbium-169 was produced via the 169Tm(p, n)169Yb nuclear process at the AMIRS (Cyclone-30, IBA, Belgium) cyclotron, irradiating Tm2O3 with proton particles of 15 MeV primary energy and 20 μA current for 20 min. Deposition of Tm2O3 on Cu substrate was carried out via by the sedimentation method. The 543 mg of thulium(III)oxide with 108 mg of ethyl cellulose
and 8 mL of acetone were used to prepare a Tm2O3 layer of 11.69 cm2. Yields of about 0.643 MBq 169Yb per μAh were experimentally obtained. 169Yb was separated in 80 ± 5% radiochemical yield using liquid–liquid extraction. Solvent extraction of no-carrier-added 169Yb from irradiated thulium(III)oxide target hydrochloric solution was investigated using di-(2-ethylhexyl)phosphoric acid
(HDEHP). 相似文献