Government Vyt Pg Autonomous College

Durg, India

Government Vyt Pg Autonomous College

Durg, India

Time filter

Source Type

Soni A.,Government Vyt Pg Autonomous College | Tiwari A.,Government Vyt Pg Autonomous College | Bajpai A.K.,Robertson College, Jabalpur
Research on Chemical Intermediates | Year: 2014

Malachite green adsorption characteristics of magnetic beads have been investigated by batch and column methods. The maximum removal percentage of malachite green (93.9 %) was obtained at pH 7-8. The Langmuir and Freundlich isotherms were used to investigate the adsorption equilibrium. It was found that the Freundlich model provides the best correlation with the equilibrium. In the column method, the BDST model was used to obtain an empirical relationship for the design of the adsorption column. The characterization of the prepared magnetic beads has been accomplished by FTIR, SEM, and XRD measurements. © Springer Science+Business Media Dordrecht 2013.


Shrivastava R.,ICFAI University, Tripura | Kaur J.,Government VYT PG Autonomous College
Ferroelectrics | Year: 2016

Ca2MgSi2O7 doped with Eu/Dy, with varying concentration of Dy3+ (0.5, 1.0, 1.5, 2.0 mol%), keeping the concentration of Eu2+ constant have been prepared using conventional high temperature solid state reaction technique. Sample prepared with specific concentration of Dy3+ (1.5 mol%) was characterized by X-ray diffraction (XRD) technique, Scanning Electron Microscopy (SEM), and TG/DTG (Thermal Gravimetry/Differential Thermogravimetry). XRD pattern of the sample confirmed the proper preparation of the sample. Scanning Electron Microscope image of the sample was taken to investigate the morphology of the sample. For judging the stability of the sample, TG/DTG (Thermal Gravimetry/Differential Thermogravimetry) studies were performed. Sample was given excitation energy from a ultra-violet source of wavelength 365 nm for 10 minutes, after which its afterglow intensity was recorded with respect to time. Phosophorence decay curves exhibited, single exponential decay with fairly good decay rates. The major cause for the persistent afterglow is the number of electrons captured in the traps created either by Dy3+ ions or oxygen vacancies and its depths from the bottom of the conduction band of host material. © 2016 Taylor & Francis Group, LLC.


Shrivastava R.,ICFAI University, Tripura | Kaur J.,Government VYT PG Autonomous College | Dash M.,ICFAI University, Tripura
Superlattices and Microstructures | Year: 2015

Abstract Present paper reports the preparation of Sr2MgSi2O7 doped with Dy3+ ions by modified high temperature solid state reaction technique. Samples were prepared for different concentration of Dy3+ (0.5, 1.0, 1.5, 2.0 and 2.5 mol%). Sample with optimum photoluminescence intensity was characterized by X-ray diffraction (XRD) technique. Observed XRD spectrum matched with crystallographic open database card specifically appeared for Sr2MgSi2O7 phosphor. This is a confirmation of proper preparation of the sample. Photoluminescence studies of these samples were done. Emission spectra exhibited 5 prominent peaks at 480, 490, 575, 590 and 660 nm respectively. In this case Dy3+ acts as an activator. Peaks centered at 480 and 490 nm are due to the transition 4F9/2 → 6H15/2 (blue color) of Dy3+ ions occupied at different sites. Similarly 575 and 590 nm peaks are originated due to transition 4F9/2 → 6H13/2 (yellow-orange color) of Dy3+ ions occupied at different sites. Emission at 660 nm is due to transition 4F9/2 → 6H11/2 (red color). CIE coordinates have been calculated for each sample and its value exhibited that, overall emission is near white light. In order to investigate the suitability of the samples as white color light sources for industrial uses, correlated color temperature (CCT) and color rendering index (CRI) were calculated. Values of CCT and CRI were found, well within the defined acceptable range. © 2015 Elsevier Ltd. All rights reserved.


Kaur J.,Government VYT PG Autonomous College | Shrivastava R.,ICFAI University, Tripura | Dubey V.,Bhilai Institute of Technology | Parganiha Y.,Government VYT PG Autonomous College
Journal of Display Technology | Year: 2016

Di-barium magnesium silicate doped with Eu2+ and Tm phosphors were prepared for different concentrations of Tm2+ ions keeping the concentration of Eu2+ as 0.5 mol%. Photoluminescence (PL) studies of prepared samples were carried out. Emission spectra exhibited optimum green color emission at 509 nm when Tm2+ was 1.5 mol%. Emission is expected to arise due to the transition of Eu2+ ions from any of the sublevels of 4d6 5f1 to its ground state (8S7/2. This sample with 1.5 mol% of Tm is taken for X-ray diffraction analysis. XRD pattern confirmed that the sample follows monoclinic structure with C 1 2/c 1 (15) space group. Scanning Electron Microscope image of the sample exhibited the uniform morphology with average particle size of 222.54 μm. Thermoluminescence (TL) glow curves of the sample for different UV irradiation were also recorded which presented single broaden peak centered at about 91°C. Phosphorescence decay curve was indicative of presence of dual exponential decaying section with a fast decay followed by a long decaying part. © 2005-2012 IEEE.


Upadhyay K.,Government Vyt Pg Autonomous College | Asthana A.,Government Vyt Pg Autonomous College | Tiwari N.,Government Vyt Pg Autonomous College
Asian Journal of Pharmaceutical and Clinical Research | Year: 2012

A simple and sensitive solid phase extractive spectrophotometric method for the determination of three sulfa drugs in bulk, in pharmaceutical dosage forms and in biological fluids was developed. The method is based upon coupling of diazotized sulfa drug with phloroglucinol in an acidic medium. The resulting yellow dye has absorption maximum at 420nm and the resulting dye is stable for several days. The Beer's law range for sulfamethoxazole, sulfacetamide and sulfadiazine in aqueous medium are 0.2-2.0, 0.2-2.0 and 0.1-1.0 μg mL -1 respectively and in extractive medium range for above drugs are 0.02-0.2, 0.02-0.2, and 0.01-0.1 μg mL-1. The molar absorptivity for the sulfa drugs is 9.21x 10 5, 7.79 x 10 5 and 1.820 x10 6 L mol -1 cm -1 respectively. The developed method is free from the interference of common excipients used in pharmaceutical dosage. The method was also used for the determination of sulfa drugs in pharmaceutical dosage as well as in human serum and urine samples.


Shrivastava R.,Government VYT PG Autonomous College | Kaur J.,Government VYT PG Autonomous College
Chinese Chemical Letters | Year: 2015

Di-barium magnesium silicate phosphors doped with europium and dysprosium were prepared under a weak reducing atmosphere. X-ray diffraction pattern of the sample was also done that confirmed the proper preparation of the phosphor. Scanning electron microscope (SEM) images confirmed that the sample has regular surface and uniform grain size distribution. Comparative studies of phosphorescence decay of Ba2MgSi2O7:Eu2+, Dy3+ phosphors with different concentration of Dy3+ were done. The phosphor with 0.5/1.5mol% of Eu/Dy, exhibited optimum green color afterglow properties. This emission is expected to arise due to transition of Eu2+ ions from any of the sublevels of 4f65d1 configuration to 8S7/2 level of the 4f7 configuration. For a suitable trap depth, the trap concentration is expected to be proportional to the concentration of Dy3+. These traps are responsible for holding the charge career for a reasonable time, subsequently for increasing the time of afterglow. Hence, optimum Dy3+ concentration produces the longer afterglow duration with higher intensity of luminescence signals. Trap depth were also calculated using thermoluminescence glow curve which was indicative of formation of traps suitable for long afterglow. © 2015 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.


Sharma N.,Government Vyt Pg Autonomous College | Tiwari A.,Government Vyt Pg Autonomous College
Desalination and Water Treatment | Year: 2016

The present research focuses on the adsorptive efficiency of nanomagnetite-loaded poly (acrylamide-co-itaconic acid) hydrogel for manganese removal from aqueous and contaminated solution by batch as well as column adsorption technique. The influence of pH, contact time, adsorbent dose, temperature, metal ion concentration, bed depth, feed flow rate and inlet metal ion concentration on the sensitivity of the removal process was inspected. The copolymer was synthesized and magnetized in situ. The sorption data was analyzed and fitted to linearized adsorption isotherm of the Langmuir and Freundlich equations, respectively. Equilibrium data fitted very well to the Freundlich model. The kinetics of sorption was analyzed using pseudo-first-order and pseudo-second-order kinetic models. Kinetic parameters, rate constants, equilibrium sorption capacities, and related correlation coefficients for each kinetic model were calculated. Different thermodynamic parameters i.e. ΔG0, ΔH0, and ΔS0 were also evaluated which proved the sorption to be feasible, spontaneous, and exothermic in nature. This hydrogel has been found to be an efficient adsorbent for manganese removal from water (>99% removal) and could be regenerated efficiently for further experiments. © 2015 Balaban Desalination Publications. All rights reserved.


Sharma N.,Government Vyt Pg Autonomous College | Tiwari A.,Government Vyt Pg Autonomous College
Desalination and Water Treatment | Year: 2016

The present research focuses on the adsorptive efficiency of nano-ZnO-loaded poly (acrylamide-co-itaconic acid) hydrogel for iron removal from synthetic as well as contaminated water by batch and column adsorption techniques. The influence of pH, contact time, adsorbent dose, temperature, and metal ion concentration on the sensitivity of the removal process was inspected. The copolymer was synthesized and nano-ZnO particles were incorporated within the polymeric matrix by in situ technique. The size, structure, and coating of nano-ZnO particles were characterized by TEM, SEM, Fourier transform infrared spectroscopy, and AFM analysis, respectively. The sorption data were analyzed and fitted to linearized adsorption isotherm of the Langmuir, Freundlich, and Temkin equations, respectively. Equilibrium data fitted very well to the Freundlich model. The kinetics of sorption was analyzed using pseudo-first-order and pseudo-second-order kinetic models. Kinetic parameters, rate constants, equilibrium sorption capacities, and related correlation coefficients for each kinetic model were calculated. Different thermodynamic parameters, i.e. ΔG°, ΔH° and ΔS° were also evaluated which proved the sorption to be feasible, spontaneous, and exothermic in nature. This hydrogel has been found to be an efficient adsorbent for iron removal from water (>99% removal) and could be regenerated efficiently for further experiments. © 2015 Balaban Desalination Publications. All rights reserved.


Sharma N.,Government Vyt Pg Autonomous College | Tiwari A.,Government Vyt Pg Autonomous College
Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry | Year: 2016

The present research focuses on removal efficiency of superparamagnetic nano iron oxide loaded poly (styrene-co-Acrylic acid) hydrogel for Zn2+ ions from aqueous solution by batch adsorption technique. The influence of pH, contact time, adsorbent dose, temperature, and metal ion concentration on the sensitivity of the removal process was inspected. Out of various kinetic models proposed, the pseudo second order seems to fit in the experimental data in the best way. Different thermodynamic parameters ΔG0, ΔH0, and ΔS0 have also been evaluated. The maximum percentage removal of Zn2+ ions (95%) was obtained at pH 7 in 120 min at room temperature (25°C). © 2016 © Taylor & Francis Group, LLC.


Upadhyay K.,Government Vyt Pg Autonomous College | Asthana A.,Government Vyt Pg Autonomous College | Tiwari N.,Government Vyt Pg Autonomous College
Research on Chemical Intermediates | Year: 2013

Two simple and sensitive spectrophotometric methods have been developed for analysis of the antipsychotic drug olanzapine in pharmaceuticals. Method A is based on liberation of iodine by reaction between the drug and potassium iodate, followed by reaction with leuco crystal violet (LCV), the color of oxidized LCV being measured at 598 nm. Method B is based on oxidation of olanzapine with chloramine-T (CAT) in acidic medium, the unconsumed CAT being determined with rhodamine B, measuring the absorbance at 550 nm. Calibration graphs were linear over the ranges of 0.05-2.0 and 0.1-1.6 μg mL-1 olanzapine for method A and B, respectively. The molar absorptivity, Sandell's sensitivity, detection limit, and quantitation limit were found to be 1.59 × 10 5, 0.00132, 0.038, and 0.117, respectively, for method A and 0.953 × 105, 0.00221, 0.064, and 0.192, respectively, for method B. The optimum conditions and other analytical parameters were evaluated. The proposed methods have been applied successfully for analysis of olanzapine in pure form and its dosage forms, and no interference was observed from common excipients present in pharmaceutical formulations. © 2012 Springer Science+Business Media B.V.

Loading Government Vyt Pg Autonomous College collaborators
Loading Government Vyt Pg Autonomous College collaborators