The Experts below are selected from a list of 240 Experts worldwide ranked by ideXlab platform
Ichiro Hanazaki - One of the best experts on this subject based on the ideXlab platform.
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Tristability in the bromate–sulfite–Hydrogencarbonate pH oscillator
Chemical Physics Letters, 2001Co-Authors: K. Chie, N. Okazaki, Yoshifumi Tanimoto, Ichiro HanazakiAbstract:Abstract The system composed of BrO 3 − , SO 3 2− , and HCO 3 − in acidic aqueous solution has been found to exhibit pH oscillations. The state diagram spanned by the initial concentrations of BrO 3 − and HCO 3 − has been determined to exhibit a tristability among the acidic and neutral steady states and the oscillatory state, in addition to several bistability regions. It is suggested that the competition between p K a of H 2 CO 3 and the decrease of pH in the neutral steady state due to the increase of initial concentration of BrO 3 − plays a crucial role in the realization of the complicated state diagram and multistabilities observed.
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tristability in the bromate sulfite Hydrogencarbonate ph oscillator
Chemical Physics Letters, 2001Co-Authors: K. Chie, N. Okazaki, Yoshifumi Tanimoto, Ichiro HanazakiAbstract:Abstract The system composed of BrO 3 − , SO 3 2− , and HCO 3 − in acidic aqueous solution has been found to exhibit pH oscillations. The state diagram spanned by the initial concentrations of BrO 3 − and HCO 3 − has been determined to exhibit a tristability among the acidic and neutral steady states and the oscillatory state, in addition to several bistability regions. It is suggested that the competition between p K a of H 2 CO 3 and the decrease of pH in the neutral steady state due to the increase of initial concentration of BrO 3 − plays a crucial role in the realization of the complicated state diagram and multistabilities observed.
Andrzej Krysztafkiewicz - One of the best experts on this subject based on the ideXlab platform.
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Studies on precipitation of highly dispersed silica from sodium metasilicate–sodium Hydrogencarbonate system
Journal of Chemical Technology & Biotechnology, 2002Co-Authors: Jolanta Żurawska, Teofil Jesionowski, Andrzej KrysztafkiewiczAbstract:A novel procedure is presented for precipitation of highly dispersed silica from sodium metasilicate solution using sodium Hydrogencarbonate. In the course of silica precipitation, hydrophobicity-inducing agents were introduced to the reactor, including derivatives of saturated and unsaturated higher fatty alcohols and nonylphenylpolyoxyethyleneglycol ethers. Silicas of variable physicochemical characteristics were obtained. Analysis of the principal physicochemical properties of the silicas was performed, their surface morphology was examined using scanning electron microscopy while particle size distribution, polydispersity and tendency to form the agglomerate structures were estimated by the dynamic light scattering technique. The zeta potential was also measured by estimation of electrophoretic mobility. Sodium Hydrogencarbonate solution was found to be a very good silica-precipitating agent in solutions of sodium metasilicate. The hydrated silica obtained demonstrated low bulk density and a high capacity to absorb paraffin oil. © 2002 Society of Chemical Industry
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studies on precipitation of highly dispersed silica from sodium metasilicate sodium Hydrogencarbonate system
Journal of Chemical Technology & Biotechnology, 2002Co-Authors: Jolanta żurawska, Teofil Jesionowski, Andrzej KrysztafkiewiczAbstract:A novel procedure is presented for precipitation of highly dispersed silica from sodium metasilicate solution using sodium Hydrogencarbonate. In the course of silica precipitation, hydrophobicity-inducing agents were introduced to the reactor, including derivatives of saturated and unsaturated higher fatty alcohols and nonylphenylpolyoxyethyleneglycol ethers. Silicas of variable physicochemical characteristics were obtained. Analysis of the principal physicochemical properties of the silicas was performed, their surface morphology was examined using scanning electron microscopy while particle size distribution, polydispersity and tendency to form the agglomerate structures were estimated by the dynamic light scattering technique. The zeta potential was also measured by estimation of electrophoretic mobility. Sodium Hydrogencarbonate solution was found to be a very good silica-precipitating agent in solutions of sodium metasilicate. The hydrated silica obtained demonstrated low bulk density and a high capacity to absorb paraffin oil. © 2002 Society of Chemical Industry
K. Chie - One of the best experts on this subject based on the ideXlab platform.
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Tristability in the bromate–sulfite–Hydrogencarbonate pH oscillator
Chemical Physics Letters, 2001Co-Authors: K. Chie, N. Okazaki, Yoshifumi Tanimoto, Ichiro HanazakiAbstract:Abstract The system composed of BrO 3 − , SO 3 2− , and HCO 3 − in acidic aqueous solution has been found to exhibit pH oscillations. The state diagram spanned by the initial concentrations of BrO 3 − and HCO 3 − has been determined to exhibit a tristability among the acidic and neutral steady states and the oscillatory state, in addition to several bistability regions. It is suggested that the competition between p K a of H 2 CO 3 and the decrease of pH in the neutral steady state due to the increase of initial concentration of BrO 3 − plays a crucial role in the realization of the complicated state diagram and multistabilities observed.
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tristability in the bromate sulfite Hydrogencarbonate ph oscillator
Chemical Physics Letters, 2001Co-Authors: K. Chie, N. Okazaki, Yoshifumi Tanimoto, Ichiro HanazakiAbstract:Abstract The system composed of BrO 3 − , SO 3 2− , and HCO 3 − in acidic aqueous solution has been found to exhibit pH oscillations. The state diagram spanned by the initial concentrations of BrO 3 − and HCO 3 − has been determined to exhibit a tristability among the acidic and neutral steady states and the oscillatory state, in addition to several bistability regions. It is suggested that the competition between p K a of H 2 CO 3 and the decrease of pH in the neutral steady state due to the increase of initial concentration of BrO 3 − plays a crucial role in the realization of the complicated state diagram and multistabilities observed.
James M Anderson - One of the best experts on this subject based on the ideXlab platform.
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Solving complex anion separation problems with a carbonate-Hydrogencarbonate gradient.
Journal of chromatography. A, 2002Co-Authors: Rakesh Bose, Raaidah Saari-nordhaus, James M AndersonAbstract:This paper describes the application of a new suppressor to solve complex anion separation problems with carbonate-Hydrogencarbonate gradients. In addition to suppressing the mobile phase and enhancing the analyte signal like any other ion chromatography suppressor, the new DS-Plus suppressor removes carbonic acid from the suppressor effluent when carbonate-Hydrogencarbonate mobile phases are used. This greatly reduces the background signal, enabling carbonate-Hydrogencarbonate gradients. Since carbonate-Hydrogencarbonate mobile phase has stronger eluting power than hydroxide or tetraborate, only dilute concentrations are needed to separate most anions. By adjusting the carbonate-Hydrogencarbonate ratio in the mobile phase, various anion mixtures including those containing organic and inorganic anions with -1 to -3 charges can be separated on one or two columns, eliminating the needs for columns with special selectivity.
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Recent advances in ion chromatography suppressor improve anion separation and detection.
Journal of chromatography. A, 2002Co-Authors: Raaidah Saari-nordhaus, James M AndersonAbstract:The Alltech DS-Plus suppressor improves and simplifies anion analysis by suppressor-based ion chromatography (IC). In addition to suppressing the mobile phase and enhancing the analyte signal, the DS-Plus suppressor removes carbonic acid from the suppressor effluent when carbonate-Hydrogencarbonate mobile phases are used, reducing the water dip that interferes with early eluting peaks, increasing detection sensitivity, and enabling carbonate-Hydrogencarbonate gradients. The ability to operate with carbonate-Hydrogencarbonate gradients places exceptional separating power in the mobile phase, forgoing the need for expensive columns with special selectivity. Continuous operation and solid-phase chemistry eliminates the need for external regenerants, switching valves, and multiple operating modes.
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New suppressor technology improves trace level anion analysis with carbonate-Hydrogencarbonate mobile phases.
Journal of Chromatography A, 2002Co-Authors: Derick R. Douglas, Raaidah Saari-nordhaus, Philippe Despres, James M AndersonAbstract:Sodium carbonate-Hydrogencarbonate mobile phases are preferred over sodium hydroxide for anion analysis by suppressor-based ion chromatography (IC). Unlike hydroxide, carbonate-Hydrogencarbonate has strong eluting power and its buffering capacity can be used as a selectivity tool for controlling separations. However, carbonate-Hydrogencarbonate mobile phases fell out of favor for trace level analysis because the carbonic acid suppressor effluent has some background conductivity, which reduces sensitivity compared to sodium hydroxide. This paper describes a new suppressor technology that improved anion analysis with carbonate-Hydrogencarbonate mobile phases. In addition to converting the carbonate-Hydrogencarbonate buffer to carbonic acid like other traditional IC suppressors, the new DS-Plus suppressor also removed carbonic acid from the suppressor effluent. Anions are now detected in water background, just like when using sodium hydroxide as the mobile phase. The lower background conductivity improves sensitivity and reduces detection limits. The water-dip often seen with conventional suppressors is greatly reduced, improving fluoride quantification.
N. Okazaki - One of the best experts on this subject based on the ideXlab platform.
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Tristability in the bromate–sulfite–Hydrogencarbonate pH oscillator
Chemical Physics Letters, 2001Co-Authors: K. Chie, N. Okazaki, Yoshifumi Tanimoto, Ichiro HanazakiAbstract:Abstract The system composed of BrO 3 − , SO 3 2− , and HCO 3 − in acidic aqueous solution has been found to exhibit pH oscillations. The state diagram spanned by the initial concentrations of BrO 3 − and HCO 3 − has been determined to exhibit a tristability among the acidic and neutral steady states and the oscillatory state, in addition to several bistability regions. It is suggested that the competition between p K a of H 2 CO 3 and the decrease of pH in the neutral steady state due to the increase of initial concentration of BrO 3 − plays a crucial role in the realization of the complicated state diagram and multistabilities observed.
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tristability in the bromate sulfite Hydrogencarbonate ph oscillator
Chemical Physics Letters, 2001Co-Authors: K. Chie, N. Okazaki, Yoshifumi Tanimoto, Ichiro HanazakiAbstract:Abstract The system composed of BrO 3 − , SO 3 2− , and HCO 3 − in acidic aqueous solution has been found to exhibit pH oscillations. The state diagram spanned by the initial concentrations of BrO 3 − and HCO 3 − has been determined to exhibit a tristability among the acidic and neutral steady states and the oscillatory state, in addition to several bistability regions. It is suggested that the competition between p K a of H 2 CO 3 and the decrease of pH in the neutral steady state due to the increase of initial concentration of BrO 3 − plays a crucial role in the realization of the complicated state diagram and multistabilities observed.
