The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Joseph A. Nuth - One of the best experts on this subject based on the ideXlab platform.
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the effect of carrier gas pressure and wall heating on the operation of the thermal diffusion cloud chamber
Journal of Chemical Physics, 2001Co-Authors: Frank T. Ferguson, Richard H Heist, Joseph A. NuthAbstract:Experimental observations indicate that the nucleation behavior within the thermal diffusion cloud chamber (TDCC) changes with increasing carrier gas pressure and applied sidewall heating, even though such an effect is not predicted by typical nucleation theories and it is not seen in typical expansion-based nucleation studies. In this work we present a model of the chamber which shows that both of these effects are likely due to buoyancy-Induced Convection within the TDCC. As the chamber pressure is increased, the calculated critical supersaturation within the chamber decreases. Results from a simple model of the chamber wall heating are also presented. Previously, it was argued that unheated chamber walls result in a significant, radial concentration gradient which lowers the vapor concentration and condensation flux within the chamber center. In contrast, we show that this reduction is due primarily to a convective flow Induced by the sidewall concentration gradient. The model has been applied to recent experimental data for n-pentanol. Results indicate that, with respect to buoyancy-Induced Convection, the typical 1D model should be regarded as an upper limit to the maximum attainable supersaturation within the chamber.
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Buoyancy-Induced Convection in the thermal diffusion cloud chamber
AIP Conference Proceedings, 2000Co-Authors: Frank T. Ferguson, Joseph A. NuthAbstract:An important question currently concerning thermal diffusion cloud chamber operation is what effect, if any, does buoyancy-Induced Convection have on measured supersaturations. In this paper we highlight some of the important results from a model of the chamber which includes such convective effects. The results indicate that the reduction in the maximum attainable supersaturation is likely to be small, but a general method of determining when these effects will become significant is needed.
Frank T. Ferguson - One of the best experts on this subject based on the ideXlab platform.
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the effect of carrier gas pressure and wall heating on the operation of the thermal diffusion cloud chamber
Journal of Chemical Physics, 2001Co-Authors: Frank T. Ferguson, Richard H Heist, Joseph A. NuthAbstract:Experimental observations indicate that the nucleation behavior within the thermal diffusion cloud chamber (TDCC) changes with increasing carrier gas pressure and applied sidewall heating, even though such an effect is not predicted by typical nucleation theories and it is not seen in typical expansion-based nucleation studies. In this work we present a model of the chamber which shows that both of these effects are likely due to buoyancy-Induced Convection within the TDCC. As the chamber pressure is increased, the calculated critical supersaturation within the chamber decreases. Results from a simple model of the chamber wall heating are also presented. Previously, it was argued that unheated chamber walls result in a significant, radial concentration gradient which lowers the vapor concentration and condensation flux within the chamber center. In contrast, we show that this reduction is due primarily to a convective flow Induced by the sidewall concentration gradient. The model has been applied to recent experimental data for n-pentanol. Results indicate that, with respect to buoyancy-Induced Convection, the typical 1D model should be regarded as an upper limit to the maximum attainable supersaturation within the chamber.
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Buoyancy-Induced Convection in the thermal diffusion cloud chamber
AIP Conference Proceedings, 2000Co-Authors: Frank T. Ferguson, Joseph A. NuthAbstract:An important question currently concerning thermal diffusion cloud chamber operation is what effect, if any, does buoyancy-Induced Convection have on measured supersaturations. In this paper we highlight some of the important results from a model of the chamber which includes such convective effects. The results indicate that the reduction in the maximum attainable supersaturation is likely to be small, but a general method of determining when these effects will become significant is needed.
M. A. Tenan - One of the best experts on this subject based on the ideXlab platform.
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Surface tension-Induced Convection as a particle aggregation mechanism
Journal of Colloid and Interface Science, 1992Co-Authors: Omar Teschke, M.u Kleinke, M. A. TenanAbstract:Abstract In the present work it is shown that Convection—diffusion processes cause a peculiar morphology of precipitated iron sulfate on the metal surface. The calculated solution velocity distribution at the electrode surface shows a pattern of square cells. This fluid motion accelerates the aggregation of particles into a preferential square-cell geometry, which was observed on the samples. The samples, which were prepared using a freeze-drying technique, show that the square pattern cell sizes have the same functional dependence on sulfuric acid concentration as on the interfacial tension variation. The stability condition for cell pattern formation and also turbulence threshold are discussed as are the wall effects on the cell nonuniformity distribution.
Richard H Heist - One of the best experts on this subject based on the ideXlab platform.
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the effect of carrier gas pressure and wall heating on the operation of the thermal diffusion cloud chamber
Journal of Chemical Physics, 2001Co-Authors: Frank T. Ferguson, Richard H Heist, Joseph A. NuthAbstract:Experimental observations indicate that the nucleation behavior within the thermal diffusion cloud chamber (TDCC) changes with increasing carrier gas pressure and applied sidewall heating, even though such an effect is not predicted by typical nucleation theories and it is not seen in typical expansion-based nucleation studies. In this work we present a model of the chamber which shows that both of these effects are likely due to buoyancy-Induced Convection within the TDCC. As the chamber pressure is increased, the calculated critical supersaturation within the chamber decreases. Results from a simple model of the chamber wall heating are also presented. Previously, it was argued that unheated chamber walls result in a significant, radial concentration gradient which lowers the vapor concentration and condensation flux within the chamber center. In contrast, we show that this reduction is due primarily to a convective flow Induced by the sidewall concentration gradient. The model has been applied to recent experimental data for n-pentanol. Results indicate that, with respect to buoyancy-Induced Convection, the typical 1D model should be regarded as an upper limit to the maximum attainable supersaturation within the chamber.
Omar Teschke - One of the best experts on this subject based on the ideXlab platform.
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Surface tension-Induced Convection as a particle aggregation mechanism
Journal of Colloid and Interface Science, 1992Co-Authors: Omar Teschke, M.u Kleinke, M. A. TenanAbstract:Abstract In the present work it is shown that Convection—diffusion processes cause a peculiar morphology of precipitated iron sulfate on the metal surface. The calculated solution velocity distribution at the electrode surface shows a pattern of square cells. This fluid motion accelerates the aggregation of particles into a preferential square-cell geometry, which was observed on the samples. The samples, which were prepared using a freeze-drying technique, show that the square pattern cell sizes have the same functional dependence on sulfuric acid concentration as on the interfacial tension variation. The stability condition for cell pattern formation and also turbulence threshold are discussed as are the wall effects on the cell nonuniformity distribution.