High Performance Liquid Chromatography (HPLC) method is a potent analytical technique for determining phytoconstituents even in minute quantities particularly that are generally present in traces concentrations in medicinal plants. The concentration of oleanolic acid (OA) in the Gentiana olivieri Griseb.(GOG) flowers is quantitatively determined by a simple, precise and accurate HPLC method. HPLC assay was performed on reversed-phase C18 column and compound was detected at 210 nm with a flow rate of 1.0 ml/min. The mobile phase consisted of methanol (A) and 0.03 mol/L phosphate buffer, pH 2.9 (B) with a ratio of 85:15 (A: B v/v).The method showed good precision and accuracy with overall intra-day and inter-day variation of 0.36-1.33% and 0.43-1.15%, respectively, and overall recoveries of 99.32%. Application of these methods to determine the OA in Gentiana olivieri Griseb showed that the concentration of OA was found more in the flower as compared to the whole aerial part (average amount in flower 1.82 mg/g DW and 0.75 mg/g DW in whole aerial plant). A simple and accurate HPLC method has been developed for quantitative determination of OA in GOG flowers.
The present work encloses structural and optical characterization of copper (I) selenide (Cu2Se) thin films. The films having thickness 85 nm have been deposited using thermal evaporation technique in initial step of work. The structural and morphological studies of deposited thin films are then done by X-ray diffraction (XRD), scanning electron microscope (SEM), and surface profilometer measurements. Later on, ultraviolet-visible-near-infrared (UV-VIS-NIR) spectrophotometer and Raman spectroscopic measurements are performed for optical characterization of films. The structure and morphology measurements reveal that deposited material of films is crystalline. The optical band gap estimated from the optical transmission spectra of the film has been found 1.90 eV. The mean values of refractive index, extinction coefficient, real and imaginary dielectric constant are received 3.035, 0.594, 9.623, and 3.598, respectively. The obtained results are compared and analyzed for justification and application of Cu2Se thin films.
The present article comprises computation of elastic, ultrasonic, and thermo-physical properties of RM (R = Tb, Dy, Ho, Er, Tm; M = Zn, Cu) compounds at 300 K. The second-order elastic constants (SOECs) and elastic moduli are evaluated initially, using potential model approach considering interaction up to second nearest neighbours. The ultrasonic velocities are obtained for wave propagation along <100>, <110>, and <111> crystallographic directions using evaluated SOECs. The Debye temperature, specific heat at constant volume, thermal energy density, thermal conductivity, and thermal relaxation time are also calculated. The obtained results are compared and analysed for justification and application of materials.
The present work is focused on the determination of elastic, mechanical, ultrasonic and thermal properties of ScRu intermetallic under the variation of pressure 0–60 GPa and particle size 5–40 nm. Initially, the second order elastic constants (SOECs) have been computed under a potential model approach, in which interaction potential is defined by Coulomb and Born–Mayer potentials. Later on, the estimation of mechanical, ultrasonic and thermo-physical parameters has been performed using SOECs. The ultrasonic velocities are estimated in the same pressure/particle size range for wave propagation along 〈100〉 crystallographic direction. It is found that elastic constants, ultrasonic velocities, Debye average velocity, specific heat at constant volume, thermal energy density, thermal conductivity and melting point enhance with increase in pressure and decay in particle size in chosen intermetallic. The analysis of the obtained results reveals that the elastic, mechanical and thermal properties of ScRu intermetallic shall enhance effectively under pressure in comparison to decay in particle size.
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