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561.
562.
This is for the first time that application of complex nanostructure is reported as pH indicator in PVC matrix. This new optical pH sensor was constructed based on incorporation of ZnLI2 complex nanostructure in PVC matrix. The synthesized nanostructure ZnLI2 complex was characterized by SEM and XRD technique. The membrane solution was speared on the glass plate to provide thin film and the membrane surface morphology was investigated via field emission scanning microscope (FE‐SEM) technique. Central composite design (CCD) combined with desirability function (DF) was applied to find the best experimental composition of membrane providing the highest absorbance. These conditions were found in correspondence with 3 mg of pH indicator, 3 mg of ionic additive and 1.5 mg/mg of DBP/PVC weight ratio. Under optimum conditions, the proposed pH sensor has two linear working ranges of 4 ‐ 8 at 393 nm (R2 = 0.9897) and 5 ‐ 8 (R2 = 0.9982) at 570 nm with response time of 4 min. The pKa of proposed pH optical sensor was calculated through three methods that found to be 5.63. The present optical sensor shows stability after 2 months without any significant divergence in response properties (less than 5% RSD). Furthermore, current pH optode was exhibited good repeatability (RSD = 1.14%) as well as reproducibility (RSD = 4.06%). No significant variation was observed on sensor response with increasing the ionic strength in the range of 0.0–0.5 M of sodium chloride. All above features indicated that the proposed sensor can be successfully used for detection of pH in solutions with different ionic strength. 相似文献
563.
Ahmad Tahershamsi Hassan Rahimzadeh Morteza Monshizadeh Hamed Sarkardeh 《Meccanica》2018,53(13):3269-3277
In the present research, hydrodynamic behavior of free surface vortices including surface displacement of the vortex core as a function of the vortex stability, relationship between the intake hydraulic parameters and vortex strength and characteristics of the vortex vertical stretching as a function of the intake hydraulic parameters were experimentally investigated in a horizontal intake. Relationship between the vortex-induced air and vortex strength was also evaluated and compared with the previous researches. In this regard, by defining a non-dimensional parameter as intake number, relationships between intake hydraulic parameters and other investigated dynamic aspects of free-surface vortices were discussed. 相似文献
564.
565.
Ahangar Zonouzi Sajjad Khodabandeh Rahmatollah Safarzadeh Habibollah Aminfar Habib Mohammadpourfard Mousa Ghanbarpour Morteza 《Journal of Thermal Analysis and Calorimetry》2020,140(6):2805-2816
Journal of Thermal Analysis and Calorimetry - In this study, the subcooled boiling heat transfer of a Fe3O4/water magnetic nanofluid flowing through a vertical tube has been investigated... 相似文献
566.
Morteza Gholami 《Natural product research》2019,33(1):126-129
Khat (Catha edulis Forsk) is a narcotic plant which contains significant amounts of amphetamines, like alkaloids. Herein, analysis of the essential oil composition showed that Khat has useful volatile chemicals in addition to its alkaloids. Results indicated that among 35 identified constituents including mono and sesquiterpenes, the diterpene kaurene, comprises the major part of the essential oil, around 50 percent of total. Kaurene is known as a potent biological agent for the treatment of cancer patients. The presence of kaurene at high levels indicates that the essential oil of Catha edulis can potentially be more effectively exploited rather than its narcotic stimulant amphetamine-like alkaloids. 相似文献
567.
568.
The interaction of oxygen of water and central oxygen of ozone produces stable H2O‐O3 complex with no barrier. With decomposition of this complex through H‐abstraction by O3 and O‐abstraction by H2O, four possible product channels have been found. The reaction of mercury and the products of water‐ozone reaction have been studied. All geometrical and AIM parameters of intermediate, transition states, and the products of reactions are calculated and thermodynamic parameters are obtained. The negative value of free energy show that channels Hg+H2OO, Hg+H2O2 and Hg+H2O4 in hydrogen tetroxide form (HTO) may be the main reaction channels. 相似文献
569.
Mahnaz Ghambarian Yadollah Yamini Ali Esrafili Najmeh Yazdanfar Morteza Moradi 《Journal of chromatography. A》2010,1217(36):5652-5658
A new concept of liquid–liquid–liquid microextraction (LLLME) was introduced based on applying two immiscible organic solvents in lumen and wall pores of hollow fiber (HF). With this methodology, analytes of interest can be extracted from aqueous sample, into a thin layer of organic solvent (dodecane) sustained in the pores of a porous hollow fiber, and further into a μL volume of organic acceptor (acetonitrile or methanol) located inside the lumen of the hollow fiber. Some chlorophenols (CPs) were selected as model compounds for developing and evaluating of the method performance. The analysis was performed by gas chromatography–electron capture detection (GC–ECD) without derivatization. The factors affecting the HF-LLLME of target compounds were investigated and the optimal extraction conditions were established. Under the optimum conditions, preconcentration factors in a range of 208–895 were obtained. The performance of the proposed method was studied in terms of linear dynamic ranges (LDRs from 0.02 to 100 ng mL−1), linearity (R2 ≥ 0.995), precision (RSD % ≤ 8.1) and limits of detection (LODs in the range of 0.006–0.2 ng mL−1). In addition to preconcentration, HF-LLLME also served as a technique for sample clean-up. 相似文献
570.
Babak Mokhtarani Ali Sharifi Hamid Reza Mortaheb Mojtaba Mirzaei Morteza Mafi Fatemeh Sadeghian 《The Journal of chemical thermodynamics》2009,41(3):323-329
Densities and viscosities of two pyridinium-based ionic liquids, 1-butylpyridinium tetrafluoroborate [BuPy][BF4] and 1-octylpyridinium tetrafluoroborate [OcPy][BF4], and their binaries with water at atmospheric pressure and temperatures from (283.15 to 348.15) K were determined. The densities and viscosities of pure ionic liquids were correlated successfully by empirical equations. The Vogel–Fulcher–Tammann equations can fit the experimental viscosities for pure and binary of both IL systems. Excess molar volume and viscosity deviation were calculated for the binaries. The excess molar volumes have positive deviation from ideal solution while the viscosity deviations have negative values. 相似文献