59 research outputs found
Optical Characterization of Zinc Modified Bismuth Silicate Glasses
Full text linkThe optical characterization of glass samples in the system 40SiO2 · xZnO · (60-x)Bi2O3 with x=0, 5, 10, 15, 20, 25, 30, 35, and 40 prepared by conventional melt-quench technique has been carried out in the light of Hydrogenic Excitonic Model (HEM). The absorption coefficient spectra show good agreement with theoretical HEM for the present glass system and the values of different parameters like Eg, R, Γ1, Γc, and Co have been estimated from fitting of this model. The values of energy band gap estimated from fitting of HEM with experimental data are in good agreement with those obtained from Tauc’s plot for direct transitions. The band gap energy is found to increase with increase of ZnO content. The decrease in values of Urbach energy with increase in ZnO content indicates a decrease in defect concentration in the glass matrix on addition of ZnO content. Optical constants n and k obey k-k consistency and the dielectric response of the studied glass system is similar to that obtained for Classical Electron Theory of Dielectric Materials. The calculated values of the metallization criterion (M) show that the synthesized glasses may be good candidates for new nonlinear optical materials
To study the effect of doping concentration of silver on structural and optical properties of cadmium oxide (CdO) nanostructure
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HPLC and HPTLC methods for simultaneous quantification of Metformin hydrochloride, Vildagliptin and Dapagliflozin propanediol with comparative evaluation by greenness and whiteness assessment tools
No full textThe combination of Vildagliptin, Dapagliflozin propanediol monohydrate and Metformin hydrochloride has been approved by Central Drug Standard Control Organization in March 2023 for conducting Phase III trial for treatment of diabetes mellitus. None of the chromatographic methods are reported for the proposed combination. In context to this, the proposed work aims to develop and validate two chromatographic methods, high HPLC and HPTLC for simultaneous estimation of the said combination followed by validation in accordance to ICH Q2(R2). For HPLC, linearity range were, 300–700, 30–70 and 3–7 µg/ml for Metformin hydrochloride, Vildagliptin and Dapagliflozin propanediol respectively. Good resolution was obtained with the final mobile phase, Acetonitrile: 10 mM potassium dihydrogen phosphate buffer pH 6.5 set with TEA (75:25 %v/v). The flow rate was 1 ml/min and detection wavelength was 214 nm. Rt of Metformin hydrochloride, Vildagliptin and Dapagliflozin propanediol was 2.262, 3.956 and 11.411 min respectively. For HPTLC the linearity range set was 1000–5000, 5000–9000 and 1000–5000 ng/band for Metformin hydrochloride, Vildagliptin and Dapagliflozin propanediol respectively. Separation of all drugs was observed using optimized mobile phase, Toluene: Ethyl acetate: 3% Ammonium acetate: Triethylamine(4: 4: 3: 0.1). Rf for Metformin hydrochloride, Vildagliptin and Dapagliflozin propanediol was 0.19, 0.48 and 0.61 respectively at 214 nm. % Relative Standard Deviation for validation parameters of both methods were found to be <2, which indicates that the methods were validated properly as per guideline. The proposed methods were specific, reliable, precise and can be applicable in routine analysis. Analytical Eco-Scale, Analytical GREEnness metric, and complex Green Analytical Procedure Index were the three methods used to assess the greenness. Furthermore, the quality (R), ecological effect (G), and economic feasibility (B) of the new technique were assessed by RGBfast tool for whiteness assessment and the applicability evaluated by the BAGI metric tool for performance verification
Optimization of HPTLC densitometric method for curcuminoids and polyphenolics in an ayurvedic Emblica officinalis and Curcuma longa based Nishamalaki formulation by Box-Behnken design
No full text719-728The present study focuses on developing a simplified, specific, and accurate high performance thin layer chromatographic (HPTLC) method for the quantitative and qualitative determination of ellagic acid, gallic acid, and curcuminoids (bisdemethoxycurcumin, demethoxycurcumin, and curcumin) in Nishamalaki Ayurvedic formulation. Pre-coated silica gel 60 F254 aluminum-backed plates were used as the stationary phase in the chromatographic technique development, and the optimized mobile phase was toluene: dichloromethane: glacial acetic acid: formic acid (6:4:1.6:0.9% v/v/v/v) with double development in linear ascending mode. The detection wavelength for quantification for ellagic and gallic acid was 280 nm, and curcuminoids (bisdemethoxycurcumin, demethoxycurcumin, and curcumin) were 430 nm. The optimized mobile phase showed optimum separation between peaks for ellagic acid, gallic acid, and curcuminoids (bisdemethoxycurcumin, demethoxycurcumin, and curcumin) at RF of 0.12±0.02, 0.21±0.02, 0.55±0.02, 0.69±0.02 and 0.82±0.02 respectively. Chromatographic conditions were optimized using the Box-Behnken design. Various variables, such as, the volume of formic acid and glacial acetic acid, and chamber saturation time, that are likely to impact RF were identified for further optimization. The volume of glacial acetic acid may be regarded as a critical method parameter, which caused the greatest change in the RF value and was the important factor among the three factors. The linear range was 600-1800 ng/band for all markers (r2 greater than 0.98). The limit of detection (LOD) and quantification (LOQ) measured indicated the method’s sensitivity. For all markers, the recovery percentage reveal acceptable accuracy, and the method was repeatable and reproducible from precision measurements with less than a 2% relative standard deviation. The optimized method was precise, specific, accurate, robust and reproducible for quantifying ellagic acid, gallic acid, and curcuminoids (bisdemethoxycurcumin, demethoxycurcumin, and curcumin) in the quality-control testing of botanical extract along with Nishamalaki ayurvedic formulation
To study the effect of calcinations durations and temperature on optical and structural properties of MgO-CuO nanocomposites
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Effect of music on post-exercise recovery rate in young healthy individuals
Full text linkBackground: Music has been used in exercise classes for many decades. The role of music in increasing the exercise performance is well recognized but there is very little information about effect of music on post-exercise recovery time.Methods: The present study was conducted to see the effect of musical sounds on post-exercise recovery time following moderate exercise with Harvard step test in young healthy volunteers. 30 young healthy volunteers (17 males, 13 females) aged between 17 to 20 years were recruited for the study. Pulse rate, systolic BP, diastolic BP were recorded prior to exercise in lying down position. The participants were subjected to moderate exercise by Harvard step test for 3 minutes on 3 consecutive days. They were allowed to rest in silence on 1st day, rest with hearing slow music on 2nd day and rest with hearing fast music on 3rd day. During the post-exercise relaxation time PR, SBP and DBP were measured immediately and after every 1 min. until the parameters returned to resting values. Data was statistically analysed using ANOVA test and 0.05 level of significance was set prior to the study.Results: The result showed that with slow music, recovery time of pulse rate (5.2 ± 2.1), systolic blood pressure (3.9 ± 1.1) and diastolic blood pressure (3.2 ± 1.7) were significantly faster as compared to both no music and fast music.Conclusion: The study concluded that music hastens post-exercise recovery and slow music has greater relaxation effect than fast or no music.
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