The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Ram S. Lokhande - One of the best experts on this subject based on the ideXlab platform.
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Studies on Ion-isotopic exchange reactIons using nuclear grade Ion exchange resins
Ionics, 2011Co-Authors: Ram S. LokhandeAbstract:The present paper deals with the study of iodide and Bromide Ion-isotopic exchange reactIons by applicatIon of radioactive tracer technique. The specific reactIon rate (per minute) of both the reactIons decreases with rise in temperature and increases with concentratIon of Ionic solutIon. It was observed that due to solvatIon effect, the iodide Ion-isotopic exchange reactIon take place at a faster rate than Bromide Ion-isotopic exchange reactIon. Also for iodide Ion-isotopic exchange reactIon, the distributIon coefficient (K d ) values were higher than that for Bromide Ion-isotopic exchange reactIon. The applicatIon of tracer technique was further extended for characterizatIon of two widely used nuclear grade Ion exchange resins TulsIon A-33 and Duolite ARA 9366. It was observed that the values of K d, specific reactIon rate (per minute), amount of Ion exchanged (millimoles), and percentage of Ions exchanged for TulsIon A-33 resins are higher than that for Duolite ARA 9366 resins under identical experimental conditIons.
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ApplicatIon of Br-82 as a radioactive tracer isotope to study Bromide Ion-isotopic exchange reactIon in strongly basic anIon exchange resin Duolite A-161
Russian Journal of Physical Chemistry A, 2009Co-Authors: Ram S. Lokhande, P. U. Singare, S. R. D. TiwariAbstract:In the present investigatIon Br-82 radioactive isotope was used as a tracer to study the kinetics of exchange reactIon taking place between the Ion exchange resin and the external Bromide Ion solutIon. In an attempt to study the reversible Bromide Ion-isotopic exchange reactIon kinetics, it was expected that whether the initial step was the exchange of radioactive Bromide Ions from the solutIon on to the Ion exchange resin (forward reactIon), or from the Ion exchange resin in to the solutIon (reverse reactIon), the two Ion-isotopic exchange reactIons should occur simultaneously, which was further confirmed from the values of specific reactIon rate 0.122 and 0.123 min^−1 respectively obtained under identical experimental conditIons. The radioactive tracer technique employed in the present investigatIon will be useful for characterizatIon of various industrial grade Ion exchange resins.
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applicatIon of radioactive tracer technique to study the kinetics and mechanism of reversible Ion isotope exchange with strongly basic anIon exchange resin indIon 850
Radiochemistry, 2008Co-Authors: Ram S. Lokhande, V V PatilAbstract:The kinetics of reversible Bromide Ion-isotope exchange with IndIon-850 resin was studied in the concentratIons range from 0.0025 to 0.100 M and the temperature varied from 27.0 to 48.0°C. Two sets of experiments were performed: exchange of the inactive resin in the Bromide form with the Bromide solutIon spiked with 82Br tracer and exchange of the labeled resin with an inactive Bromide solutIon. For both forward and reverse Bromide Ion-isotope exchange reactIons, the rate constants, amount of Bromide Ions exchanged, and initial rate of Bromide Ion exchange were calculated. The rate constants of the forward and reverse reactIons are essentially equal. In both cases, the amount of Bromide Ion exchanged and the initial rate of Bromide Ion exchange increase with temperature.
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kinetics of Bromide Ion isotope exchange with weakly basic macroporous resin indIon 860
Radiochemistry, 2008Co-Authors: Ram S. Lokhande, P. U. Singare, S. R. D. TiwariAbstract:Kinetics of Bromide Ion-isotope exchange with weakly basic macroporous resin IndIon-860 was studied. Two sets of experiments were performed. In the first set, inactive Ion-exchange resin samples in the Bromide form were equilibrated with a radioactive Bromide solutIon spiked with 82Br tracer, and in the second set of experiments, labeled radioactive Ion-exchange resin samples in the Bromide form were equilibrated with an inactive Bromide solutIon. The temperature was varied from 25.0 to 40.0°C, and the concentratIon of Bromide Ions in solutIon, from 0.005 to 0.100 M. In separate experiments, performed at a fixed temperature of 25.0°C using 0.0100 M Bromide Ion solutIon, the amount of the labeled radioactive Ion-exchange resin was varied from 0.250 to 1.000 g. Essentially similar rate constants were obtained for the forward and reverse reactIons.
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the kinetics and mechanism of Bromide Ion isotope exchange reactIon in strongly basic anIon exchange resin duolite a 162 determined by the radioactive tracer technique
Russian Journal of Physical Chemistry A, 2007Co-Authors: Ram S. Lokhande, P. U. Singare, P KarthikeyanAbstract:In the present investigatIon, 82Br radioactive isotope was used as a tracer to study the kinetics and mechanism of exchange reactIon between an Ion exchange resin and an external Bromide Ion solutIon. In an attempt to study the reversible Bromide Ion isotopic exchange reactIon kinetics, it was expected that whether the initial step was the exchange of radioactive Bromide Ions from the solutIon into the Ion exchange resin (forward reactIon) or from the Ion exchange resin into the solutIon (reverse reactIon), two Ion isotopic exchange reactIons should occur simultaneously, which was further confirmed by the experimental specific reactIon rates of 0.130 and 0.131 min−1, respectively. The results can be used to standardize process parameters so as to optimize the utilizatIon of Ion exchange resins in various industrial applicatIons.
Jo Shu Chang - One of the best experts on this subject based on the ideXlab platform.
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surfactant ctab assisted flower like bi2wo6 through hydrothermal method unintentIonal Bromide Ion doping and photocatalytic activity
Catalysis Communications, 2017Co-Authors: Heshan Zheng, Wanqian Guo, Renli Yin, Xiaochi Feng, Nanqi Ren, Jo Shu ChangAbstract:Abstract In additIon to morphology control, the unnoticed doping effect of adding surfactant CTAB in hydrothermal synthesis of visible-light driven photocatalyst was also found. In the meantime of assisting the microstructure assembling to higher ‘surface accessibility’, a small amount of doped Br-lowered the band gap of Bi2WO6 and expanded its optical absorptIon in visible light regIon and thus further improved the photocatalytic performance. To our knowledge, this is the first study reporting this doping effect of surfactants. We expect to provide new insights into the roles of surfactants participating in photocatalyst synthesis.
P. U. Singare - One of the best experts on this subject based on the ideXlab platform.
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Studies on kinetics and thermodynamics of Ion adsorptIon reactIons by applicatIons of short-lived radioactive tracer isotopes
Ionics, 2016Co-Authors: P. U. SingareAbstract:The short-lived radiotracer isotopes were applied to study the kinetics and thermodynamic feasibility of iodide as well as Bromide Ion adsorptIon reactIons using industrial-grade resin materials. Free energy of activatIon (Δ G ^‡) and energy of activatIon ( E _a) were calculated by using Arrhenius equatIon, enthalpy of activatIon (Δ H ^‡), and entropy of activatIon (Δ S ^‡) calculated by using the Eyring-Polanyi equatIon. These parameters were used to predict the thermodynamic feasibility of the two Ion adsorptIon reactIons performed by using Dowex SBR LC and IndIon-810 resins. It was observed that during iodide Ion adsorptIon reactIons, the values of energy of activatIon (−18.79 kJ mol^−1), enthalpy of activatIon (−21.37 kJ mol^−1), free energy of activatIon (58.13 kJ mol^−1), and entropy of activatIon (−0.26 kJ K^−1 mol^−1) calculated for IndIon-810 resins were lower than the respective values of −4.28 kJ mol^−1, −6.87 kJ mol^−1, 64.97 kJ mol^−1, and −0.23 kJ K^−1 mol^−1 calculated for Dowex SBR LC under similar experimental conditIons. Identical trends were observed for the two resins during Bromide Ion adsorptIon reactIons. The low values of different thermodynamic parameters obtained for IndIon-810 resins during both the Ion adsorptIon reactIons indicate that the reactIons are thermodynamically more feasible using IndIon-810 resins as compared to Dowex SBR LC resins. It is expected here that the present nondestructive technique can be extended further for different Ions in the solutIon in order to predict the thermodynamic feasibility of different Ion adsorptIon reactIons for the range of resins which are widely used for treatment of industrial waste water effluent.
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study on distributIon coefficient of Bromide Ions from aqueous solutIon on Ion exchange resins indIon 850 indIon 860 and indIon ff ip
European Journal of Chemistry, 2010Co-Authors: P. U. Singare, R S Lokhande, Vinayak Patil, Tirtha Prabhavalkar, Santoshi TiwariAbstract:The Ion exchange resin IndIon-850, IndIon-860 and IndIon FF-IP, in Bromide form were equilibrated separately with the labeled radioactive Bromide Ion solutIon of different concentratIons varying from 0.005 M to 0.100 M in the temperature range of 25.0 oC to 45.0 oC. The Kd values of Bromide Ions were observed to be high for IndIon-850 and least for IndIon 860, while IndIon FF-IP shows intermediate Kd values under identical experimental conditIons. The difference in Kd values of Bromide Ions for the three resins is mainly because of the swelling pressure which depends on their water holding capacities.
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applicatIon of radioactive tracer technique for characterizatIon of strongly basic anIon exchange resins duolite a 101d and duolite a 102d1
Radiochemistry, 2010Co-Authors: R S Lokhande, P. U. Singare, A R KolteAbstract:The radioactive 82Br was used as a tracer to study the Bromide self-diffusIon reactIons. The effect of temperature, concentratIon of Ionic solutIon, and amount of Ion-exchange resin on the kinetics of exchange reactIons was examined. Under identical experimental conditIons, the specific reactIon rate, amount of Bromide Ions exchanged, and initial rate of Bromide Ion exchange calculated for Duolite A 101D resin were higher than those calculated for Duolite A 102D resin. The difference in the values calculated for the two resins was attributed to their water-holding capacities. The probable mechanism of Bromide isotope exchange reactIon was also predicted by comparing the specific reactIon rate of rapid and slow exchange process. It is expected that the same technique can be employed to assess the efficiency of various Ion exchangers under different operating conditIons.
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ApplicatIon of Br-82 as a radioactive tracer isotope to study Bromide Ion-isotopic exchange reactIon in strongly basic anIon exchange resin Duolite A-161
Russian Journal of Physical Chemistry A, 2009Co-Authors: Ram S. Lokhande, P. U. Singare, S. R. D. TiwariAbstract:In the present investigatIon Br-82 radioactive isotope was used as a tracer to study the kinetics of exchange reactIon taking place between the Ion exchange resin and the external Bromide Ion solutIon. In an attempt to study the reversible Bromide Ion-isotopic exchange reactIon kinetics, it was expected that whether the initial step was the exchange of radioactive Bromide Ions from the solutIon on to the Ion exchange resin (forward reactIon), or from the Ion exchange resin in to the solutIon (reverse reactIon), the two Ion-isotopic exchange reactIons should occur simultaneously, which was further confirmed from the values of specific reactIon rate 0.122 and 0.123 min^−1 respectively obtained under identical experimental conditIons. The radioactive tracer technique employed in the present investigatIon will be useful for characterizatIon of various industrial grade Ion exchange resins.
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kinetics of Bromide Ion isotope exchange with weakly basic macroporous resin indIon 860
Radiochemistry, 2008Co-Authors: Ram S. Lokhande, P. U. Singare, S. R. D. TiwariAbstract:Kinetics of Bromide Ion-isotope exchange with weakly basic macroporous resin IndIon-860 was studied. Two sets of experiments were performed. In the first set, inactive Ion-exchange resin samples in the Bromide form were equilibrated with a radioactive Bromide solutIon spiked with 82Br tracer, and in the second set of experiments, labeled radioactive Ion-exchange resin samples in the Bromide form were equilibrated with an inactive Bromide solutIon. The temperature was varied from 25.0 to 40.0°C, and the concentratIon of Bromide Ions in solutIon, from 0.005 to 0.100 M. In separate experiments, performed at a fixed temperature of 25.0°C using 0.0100 M Bromide Ion solutIon, the amount of the labeled radioactive Ion-exchange resin was varied from 0.250 to 1.000 g. Essentially similar rate constants were obtained for the forward and reverse reactIons.
J.j.t.i. Boesten - One of the best experts on this subject based on the ideXlab platform.
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movement of water Bromide and the pesticides ethoprophos and bentazone in a sandy soil the vredepeel data set
Agricultural Water Management, 2000Co-Authors: J.j.t.i. BoestenAbstract:The aim of this study was to collect a data set suitable for testing pesticide leaching models in the case of a Dutch sandy soil with a shallow groundwater table. The movement of water, Bromide Ion and the behaviour of the pesticides ethoprophos and bentazone was studied. The substances were applied after sowing winter wheat in autumn 1990. This late applicatIon time is unusual for bentazone: it was selected on scientific grounds (without agricultural purpose). Rainfall, groundwater level and soil temperature were monitored continuously at the experimental field (80 m long and 54 m wide) until spring 1992. Soil profiles were sampled at 1, 103, 278 and 474 days after applicatIon (16 profiles at each date). In the laboratory, pesticide transformatIon rates were measured with soil material from 0–25, 50–100 and 100–200 cm depth. SorptIon isotherms were measured with material from 0–25 cm depth. ConcentratIon profiles showed that mobility increased in the sequence ethoprophos — bentazone — Bromide Ion. Ethoprophos movement was limited to the top 25 cm layer whereas bentazone leached to below 1 m depth. At the end of the study, the concentratIons of ethoprophos and bentazone were below the detectIon limit (0.2–2 μg dm−3) in all soil layers between 25 and 120 cm depth. Recommended values for the most important input parameters of pesticide leaching models are presented.
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movement of water Bromide Ion and the pesticides ethoprophos and bentazone measured in a sandy soil in vredepeel the netherlands
1999Co-Authors: J.j.t.i. BoestenAbstract:The aim of this study was to collect a data set suitable for testing pesticide leaching models in the case of a Dutch sandy soil with a shallow groundwater table. The movement of water, Bromide Ion and the behaviour of the pesticides ethoprophos and bentazone was studied. The substances were applied after sowing winter wheat in autumn 1990. This late applicatIon time is unusual for bentazone: it was selected on scientific grounds (without agricultural purpose). Rainfall, groundwater level and soil temperature were monitored continuously at the experimental field (80 m long and 54 m wide) until spring 1992. Soil profiles were sampled at 1, 22, 42, 103, 214, 278 and 474 d after applicatIon (16 profiles at each date). In the laboratory, pesticide transformatIon rates were measured with soil material from 0-25, 50-100 and 100-200 cm depth. SorptIon isotherms were measured with material from 0-25 cm depth. ConcentratIon profiles showed that mobility increased in the sequence ethoprophos - bentazone - Bromide Ion. Ethoprophos movement was limited to the top 25 cm layer whereas bentazone leached to below 1 m depth. At the end of the study, the concentratIons of ethoprophos and bentazone were below the detectIon limit (0.2-2 g dm-3) in all soil layers between 25 and 120 cm depth.
Michael L Klein - One of the best experts on this subject based on the ideXlab platform.
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an ab initio study of water molecules in the Bromide Ion solvatIon shell
Journal of Chemical Physics, 2002Co-Authors: Simone Raugei, Michael L KleinAbstract:The solvatIon shell structure and dynamics of Br− in an aqueous solutIon of HBr (1.6 M) was studied, under ambient conditIons, by ab initio molecular dynamics using the Car–Parrinello approach. The present calculatIons indicate that Br− is asymmetrically solvated by water. The calculated residence time of water in the inner Br− anIon solvatIon shell agrees well with the most recent experimental estimate. Analysis indicates that the large anIon scarcely influences the molecular dipole moment of solvatIon shell molecules.
