The Experts below are selected from a list of 53811 Experts worldwide ranked by ideXlab platform
Sang Eon Park - One of the best experts on this subject based on the ideXlab platform.
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effect of the Average Particle Size and the surface oxidation layer of silicon on the colloidal silica Particle through direct oxidation
Materials Science and Engineering B-advanced Functional Solid-state Materials, 2009Co-Authors: Won Kyun Na, Sang Eon ParkAbstract:Abstract Colloidal silica was prepared using a direct oxidation process of silicon powders with different purities, Average Particle Sizes, and surface oxidation layer thicknesses in a water solvent with the base catalysts. Purities of 97.00–99.96% and Average Particle Sizes of 200 and 500 mesh of silicon starting materials were evaluated. The materials were thermally oxidized for 3, 16, and 30 h to observe the effect of the surface oxidation layer on the formation of colloidal silica. The longer the thermal oxidation time, the higher the oxide layer thickness on the silicon, and the larger the Average Size of silica Particle observed in the product of colloidal silica when silicon Particles had the oxide layer up to approximately 50 nm. When the oxide film was higher than 50 nm, the silica Particle Size did not increase with an increase in the oxide layer of silicon. The dependence of the Average Particle silica Size on the oxide layer thickness of silicon was observed to be smaller in the colloidal silica from the 200 mesh Size of silicon than from the 500 mesh Size. The Average Particle Size of silicon was found to affect the Average Particle Size of silica in the direct oxidation, however the correlation between the purity of silicon and the Average Particle Size of silica was not determined as it fell outside the range of this experiment.
Yuheng Zhang - One of the best experts on this subject based on the ideXlab platform.
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Infrared transmittance spectra of the granular perovskite
Journal of Physics: Condensed Matter, 1998Co-Authors: Kebin Li, Rongsheng Cheng, Shouguo Wang, Yuheng ZhangAbstract:Infrared (IR) transmittance spectra were measured for a series of samples with different Particle Sizes. Two extra absorption peaks appear when the Average Particle Size of the samples is smaller than 60 nm; these peaks can be ascribed to the surface stretching and bending modes of the octahedra. When the Average Particle Size decreases, the absorption strength of the surface modes increases while that of the bulk modes reduces.
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Infrared transmittance spectra of the granular perovskite La2/3Ca1/3MnO3
Journal of Physics Condensed Matter, 1998Co-Authors: Kebin Li, Rongsheng Cheng, Shouguo Wang, Yuheng ZhangAbstract:Infrared (IR) transmittance spectra were measured for a series of ##IMG## [http://ej.iop.org/images/0953-8984/10/19/019/img10.gif] samples with different Particle Sizes. Two extra absorption peaks appear when the Average Particle Size of the samples is smaller than 60 nm; these peaks can be ascribed to the surface stretching and bending modes of the ##IMG## [http://ej.iop.org/images/0953-8984/10/19/019/img11.gif] octahedra. When the Average Particle Size decreases, the absorption strength of the surface modes increases while that of the bulk modes reduces.
Salmah Yusof - One of the best experts on this subject based on the ideXlab platform.
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Optimization of the contents of Arabic gum, xanthan gum and orange oil affecting turbidity, Average Particle Size, polydispersity index and density in orange beverage emulsion
Food Hydrocolloids, 2008Co-Authors: Hamed Mirhosseini, Nazimah Hamid, Salmah YusofAbstract:This paper focuses on the development of an effective methodology to determine the optimum levels of three independent variables leading to (a) maximize turbidity, (b) minimize polydispersity index (PDI) and (c) obtain the target value for Average Particle Size and density of orange beverage emulsion. A three-factor central composite design (CCD) was employed to determine the effect of Arabic gum content (7–13% w/w), xanthan gum content (0.1–0.3% w/w) and orange oil content (6–10% w/w). The emulsion properties studied as response variables were: turbidity (Y1), Average Particle Size (Y2), PDI (Y3) and density (Y4). The response surface analysis was carried out to create efficient empirical models for predicting the changes of response variables. In general, analysis of variance (ANOVA) showed high coefficients of determination values (R2) in the range of 0.922–0.975 for the response surface models, thus ensuring a satisfactory adjustment of the polynomial regression models with the experimental data. The results of regression analysis indicated that more than 92% the response variation could be explained by the models. The results also indicated that the linear term of xanthan gum was the most significant (p
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optimization of the contents of arabic gum xanthan gum and orange oil affecting turbidity Average Particle Size polydispersity index and density in orange beverage emulsion
Food Hydrocolloids, 2008Co-Authors: Hamed Mirhosseini, Nazimah Hamid, Salmah YusofAbstract:This paper focuses on the development of an effective methodology to determine the optimum levels of three independent variables leading to (a) maximize turbidity, (b) minimize polydispersity index (PDI) and (c) obtain the target value for Average Particle Size and density of orange beverage emulsion. A three-factor central composite design (CCD) was employed to determine the effect of Arabic gum content (7–13% w/w), xanthan gum content (0.1–0.3% w/w) and orange oil content (6–10% w/w). The emulsion properties studied as response variables were: turbidity (Y1), Average Particle Size (Y2), PDI (Y3) and density (Y4). The response surface analysis was carried out to create efficient empirical models for predicting the changes of response variables. In general, analysis of variance (ANOVA) showed high coefficients of determination values (R2) in the range of 0.922–0.975 for the response surface models, thus ensuring a satisfactory adjustment of the polynomial regression models with the experimental data. The results of regression analysis indicated that more than 92% the response variation could be explained by the models. The results also indicated that the linear term of xanthan gum was the most significant (p<0.05) variable affecting the overall responses. The multiple optimization results showed that the overall optimum region with high total desirability (D=0.92) was found to be at the combined level of 13.88% w/w Arabic gum content, 0.27% w/w xanthan gum content and 11.27% w/w orange oil content. Under the optimum condition, the corresponding predicted response values for turbidity, Average Particle Size, PDI and density of the desirable orange beverage emulsion were 129.55, 988, 0.261 and 1.03, respectively. For validation of the models, the experimental values were compared with predicted values to check the adequacy of the models. The experimental values were found to be in agreement with those predicted, thus indicating suitability of the models employed using response surface methodology (RSM) for optimizing the physical properties of the orange beverage emulsion.
Can Erkey - One of the best experts on this subject based on the ideXlab platform.
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control of Average Particle Size of carbon aerogel supported platinum nanoParticles by supercritical deposition
Microporous and Mesoporous Materials, 2017Co-Authors: şansim Bengisu Barim, Ayse Bayrakceken, Selmi Erim Bozbag, Lichun Zhang, Riza Kizilel, M Aindow, Can ErkeyAbstract:Abstract Supercritical deposition was used to syntheSize Pt/carbon aerogel (Pt/CA) electrocatalysts. CAs with Average pore diameters of 6, 8 and 19 nm (CA6, CA8 and CA19, respectively) were syntheSized and impregnated with Pt(cod)me 2 precursor using supercritical carbon dioxide followed by the thermal conversion of the Pt precursor into its metallic form under N 2 atmosphere at various temperatures between 200 and 1000 °C. All of the prepared CAs have high surface areas with very sharp pore Size distributions. XRD and TEM results show increased Pt Particle Size with increasing conversion temperature with a homogenous distribution of nanoParticles on the CA supports. Cyclic voltammetry was used to determine the effect of CA pore properties on electrocatalytic activity. At a conversion temperature of 400 °C, the highest and lowest electrochemical surface area values were obtained for Pt/CA19 and Pt/CA6 of (126 and 36 m 2 /g, respectively). Furthermore, Pt/CA19 showed good mass activity whereas Pt/CA6 and Pt/CA8 had lower activity values towards the Oxygen Reduction Reaction (ORR). The mass activity values for Pt/CA19 increased with increasing conversion temperature, except for the sample converted at 1000 °C which exhibited the lowest mass activity. The specific activity increased significantly with the conversion temperature up to 600 °C which gave a value six times that obtained at 200 °C. At 800 °C, the specific activity decreased slightly, probably due to a change in the CA structure at this elevated conversion temperature. The Pt/CA19 sample converted at 600 °C exhibited the best performance with a mass activity of 0.1 A/mg Pt and a specific activity of 0.24 mA/cm 2 .
Won Kyun Na - One of the best experts on this subject based on the ideXlab platform.
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effect of the Average Particle Size and the surface oxidation layer of silicon on the colloidal silica Particle through direct oxidation
Materials Science and Engineering B-advanced Functional Solid-state Materials, 2009Co-Authors: Won Kyun Na, Sang Eon ParkAbstract:Abstract Colloidal silica was prepared using a direct oxidation process of silicon powders with different purities, Average Particle Sizes, and surface oxidation layer thicknesses in a water solvent with the base catalysts. Purities of 97.00–99.96% and Average Particle Sizes of 200 and 500 mesh of silicon starting materials were evaluated. The materials were thermally oxidized for 3, 16, and 30 h to observe the effect of the surface oxidation layer on the formation of colloidal silica. The longer the thermal oxidation time, the higher the oxide layer thickness on the silicon, and the larger the Average Size of silica Particle observed in the product of colloidal silica when silicon Particles had the oxide layer up to approximately 50 nm. When the oxide film was higher than 50 nm, the silica Particle Size did not increase with an increase in the oxide layer of silicon. The dependence of the Average Particle silica Size on the oxide layer thickness of silicon was observed to be smaller in the colloidal silica from the 200 mesh Size of silicon than from the 500 mesh Size. The Average Particle Size of silicon was found to affect the Average Particle Size of silica in the direct oxidation, however the correlation between the purity of silicon and the Average Particle Size of silica was not determined as it fell outside the range of this experiment.
