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Heikki Lihavainen - One of the best experts on this subject based on the ideXlab platform.
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the Homogeneous Nucleation of 1 pentanol in a laminar flow diffusion chamber the effect of pressure and kind of carrier gas
Journal of Chemical Physics, 2008Co-Authors: David Brus, Y Viisanen, Vladimír Ždímal, A P Hyvarinen, Jan Wedekind, Jiři Smolik, Heikki LihavainenAbstract:The influence of total pressure and kind of carrier gas on Homogeneous Nucleation rates of 1-pentanol was investigated using experimental method of laminar flow diffusion chamber in this study. Two different carrier gases (helium and argon) were used in the total pressure range from 50to400kPa. Nucleation temperatures ranged from 265to290K for 1-pentanol-helium and from 265to285K for 1-pentanol-argon. Nucleation rates varied between 101 and 106cm−3s−1 for 1-pentanol-helium and between 102 and 105cm−3s−1 for 1-pentanol-argon. Both positive and slight negative pressure effects were observed depending on temperature and carrier gas. The trend of pressure effect was found similar for both carrier gases. Error analysis on thermodynamic properties was conducted, and the lowering of surface tension due to adsorption of argon on nucleated droplets was estimated. A quantitative overview of pressure effect is provided.
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the carrier gas pressure effect in a laminar flow diffusion chamber Homogeneous Nucleation of n butanol in helium
Journal of Chemical Physics, 2006Co-Authors: A P Hyvarinen, Y Viisanen, Vladimír Ždímal, David Brus, Markku Kulmala, Jiři Smolik, Heikki LihavainenAbstract:Homogeneous Nucleation rate isotherms of n-butanol+helium were measured in a laminar flow diffusion chamber at total pressures ranging from 50to210kPa to investigate the effect of carrier gas pressure on Nucleation. Nucleation temperatures ranged from 265to280K and the measured Nucleation rates were between 102 and 106cm−3s−1. The measured Nucleation rates decreased as a function of increasing pressure. The pressure effect was strongest at pressures below 100kPa. This negative carrier gas effect was also temperature dependent. At Nucleation temperature of 280K and at the same saturation ratio, the maximum deviation between Nucleation rates measured at 50 and 210kPa was about three orders of magnitude. At Nucleation temperature of 265K, the effect was negligible. Qualitatively the results resemble those measured in a thermal diffusion cloud chamber. Also the slopes of the isothermal Nucleation rates as a function of saturation ratio were different as a function of total pressure, 50kPa isotherms yielded th...
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Homogeneous Nucleation rate measurements of 1 butanol in helium a comparative study of a thermal diffusion cloud chamber and a laminar flow diffusion chamber
Journal of Chemical Physics, 2005Co-Authors: David Brus, Vladimír Ždímal, A P Hyvarinen, Heikki LihavainenAbstract:Isothermal Homogeneous Nucleation rates of 1-butanol were measured both in a thermal diffusion cloud chamber and in a laminar flow diffusion chamber built recently at the Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, Prague, Czech Republic. The chosen system 1-butanol-helium can be studied reasonably well in both devices, in the overlapping range of temperatures. The results were compared with those found in the literature and those measured by Lihavainen in a laminar flow diffusion chamber of a similar design. The same isotherms measured with the thermal diffusion cloud chamber occur at highest saturation ratios of the three devices. Isotherms measured with the two laminar flow diffusion chambers are reasonably close together; the measurements by Lihavainen occur at lowest saturation ratios. The temperature dependences observed were similar in all three devices. The molecular content of critical clusters was calculated using the Nucleation theorem and compared wit...
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Homogeneous Nucleation rate measurements of 1 butanol in helium a comparative study of a thermal diffusion cloud chamber and a laminar flow diffusion chamber
Journal of Chemical Physics, 2005Co-Authors: David Brus, Vladimír Ždímal, A P Hyvarinen, Heikki LihavainenAbstract:Isothermal Homogeneous Nucleation rates of 1-butanol were measured both in a thermal diffusion cloud chamber and in a laminar flow diffusion chamber built recently at the Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, Prague, Czech Republic. The chosen system 1-butanol-helium can be studied reasonably well in both devices, in the overlapping range of temperatures. The results were compared with those found in the literature and those measured by Lihavainen in a laminar flow diffusion chamber of a similar design. The same isotherms measured with the thermal diffusion cloud chamber occur at highest saturation ratios of the three devices. Isotherms measured with the two laminar flow diffusion chambers are reasonably close together; the measurements by Lihavainen occur at lowest saturation ratios. The temperature dependences observed were similar in all three devices. The molecular content of critical clusters was calculated using the Nucleation theorem and compared with the Kelvin equation. Both laminar flow diffusion chambers provided very similar sizes slightly above the Kelvin equation, whereas the thermal diffusion cloud chamber suggests critical cluster sizes significantly smaller. The results found elsewhere in the literature were in reasonable agreement with our results.
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Homogeneous Nucleation of n pentanol in a laminar flow diffusion chamber
Journal of Chemical Physics, 2001Co-Authors: Heikki Lihavainen, Y ViisanenAbstract:Nucleation rate isotherms of n-pentanol were measured in laminar flow diffusion chamber. n-pentanol was chosen for nucleating vapor and helium for carrier gas as a part of a world wide joint experiment on Homogeneous Nucleation. Experimental temperature range was from 260 to 290 K. Experimental Nucleation rate range was from 103 to 107 cm−3 s−1. The results were compared to the classical Nucleation theory and experimental data found in literature. Experimental results were three orders of magnitude higher than predicted by the theory. The difference was constant over the whole experimental range. The saturation ratio dependency of Nucleation rate was well predicted by the theory. The number of molecules in the critical clusters was quite consistent with the theory. The results were in reasonable agreement with data found in literature.
David Brus - One of the best experts on this subject based on the ideXlab platform.
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Homogeneous Nucleation rate measurements in supersaturated water vapor ii
Journal of Chemical Physics, 2008Co-Authors: David Brus, Vladimír Ždímal, Hermann UchtmannAbstract:The Homogeneous Nucleation of water was studied experimentally in this work using a thermal diffusion cloud chamber; droplets were counted by the photomultiplier method and helium was used as a carrier gas. The Nucleation rates range from 3×10−2 to 3×101 cm−3 s−1 and six isotherms from 295 to 320 K with step of 5 K are measured. The experimental setup and obtained data are mutually compared to our previous publication [Brus et al., J. Chem. Phys. 129, 174501 (2008)], where the droplets were counted using digital photography and image processing. The molecular content of the critical clusters was estimated from the slopes of experimental data. The measured isothermal dependencies of the Nucleation rate of water on the saturation ratio were compared with previously published data of others, several theoretical predictions, and the former Nucleation onset data. The aim of the present investigation was to show for the first time that Nucleation results can be quantitatively reproduced with two different exper...
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the Homogeneous Nucleation of 1 pentanol in a laminar flow diffusion chamber the effect of pressure and kind of carrier gas
Journal of Chemical Physics, 2008Co-Authors: David Brus, Y Viisanen, Vladimír Ždímal, A P Hyvarinen, Jan Wedekind, Jiři Smolik, Heikki LihavainenAbstract:The influence of total pressure and kind of carrier gas on Homogeneous Nucleation rates of 1-pentanol was investigated using experimental method of laminar flow diffusion chamber in this study. Two different carrier gases (helium and argon) were used in the total pressure range from 50to400kPa. Nucleation temperatures ranged from 265to290K for 1-pentanol-helium and from 265to285K for 1-pentanol-argon. Nucleation rates varied between 101 and 106cm−3s−1 for 1-pentanol-helium and between 102 and 105cm−3s−1 for 1-pentanol-argon. Both positive and slight negative pressure effects were observed depending on temperature and carrier gas. The trend of pressure effect was found similar for both carrier gases. Error analysis on thermodynamic properties was conducted, and the lowering of surface tension due to adsorption of argon on nucleated droplets was estimated. A quantitative overview of pressure effect is provided.
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the carrier gas pressure effect in a laminar flow diffusion chamber Homogeneous Nucleation of n butanol in helium
Journal of Chemical Physics, 2006Co-Authors: A P Hyvarinen, Y Viisanen, Vladimír Ždímal, David Brus, Markku Kulmala, Jiři Smolik, Heikki LihavainenAbstract:Homogeneous Nucleation rate isotherms of n-butanol+helium were measured in a laminar flow diffusion chamber at total pressures ranging from 50to210kPa to investigate the effect of carrier gas pressure on Nucleation. Nucleation temperatures ranged from 265to280K and the measured Nucleation rates were between 102 and 106cm−3s−1. The measured Nucleation rates decreased as a function of increasing pressure. The pressure effect was strongest at pressures below 100kPa. This negative carrier gas effect was also temperature dependent. At Nucleation temperature of 280K and at the same saturation ratio, the maximum deviation between Nucleation rates measured at 50 and 210kPa was about three orders of magnitude. At Nucleation temperature of 265K, the effect was negligible. Qualitatively the results resemble those measured in a thermal diffusion cloud chamber. Also the slopes of the isothermal Nucleation rates as a function of saturation ratio were different as a function of total pressure, 50kPa isotherms yielded th...
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Homogeneous Nucleation rate measurements of 1 propanol in helium the effect of carrier gas pressure
Journal of Chemical Physics, 2006Co-Authors: David Brus, Vladimír Ždímal, Frank StratmannAbstract:Kinetics of Homogeneous Nucleation in supersaturated vapor of 1-propanol was studied using an upward thermal diffusion cloud chamber. Helium was used as a noncondensable carrier gas and the influence of its pressure on observed Nucleation rates was investigated. The isothermal Nucleation rates were determined by a photographic method that is independent on any Nucleation theory. In this method, the trajectories of growing droplets are recorded using a charge coupled device camera and the distribution of local Nucleation rates is determined by image analysis. The Nucleation rate measurements of 1-propanol were carried out at four isotherms 260, 270, 280, and 290K. In addition, the pressure dependence was investigated on the isotherms 290K (50, 120, and 180kPa) and 280K (50 and 120kPa). The isotherm 270K was measured at 25kPa and the isotherm 260K at 20kPa. The experiments confirm the earlier observations from several thermal diffusion chamber investigations that the Homogeneous Nucleation rate of 1-propano...
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Homogeneous Nucleation rate measurements of 1 butanol in helium a comparative study of a thermal diffusion cloud chamber and a laminar flow diffusion chamber
Journal of Chemical Physics, 2005Co-Authors: David Brus, Vladimír Ždímal, A P Hyvarinen, Heikki LihavainenAbstract:Isothermal Homogeneous Nucleation rates of 1-butanol were measured both in a thermal diffusion cloud chamber and in a laminar flow diffusion chamber built recently at the Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, Prague, Czech Republic. The chosen system 1-butanol-helium can be studied reasonably well in both devices, in the overlapping range of temperatures. The results were compared with those found in the literature and those measured by Lihavainen in a laminar flow diffusion chamber of a similar design. The same isotherms measured with the thermal diffusion cloud chamber occur at highest saturation ratios of the three devices. Isotherms measured with the two laminar flow diffusion chambers are reasonably close together; the measurements by Lihavainen occur at lowest saturation ratios. The temperature dependences observed were similar in all three devices. The molecular content of critical clusters was calculated using the Nucleation theorem and compared wit...
Vladimír Ždímal - One of the best experts on this subject based on the ideXlab platform.
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Homogeneous Nucleation rate measurements in supersaturated water vapor ii
Journal of Chemical Physics, 2008Co-Authors: David Brus, Vladimír Ždímal, Hermann UchtmannAbstract:The Homogeneous Nucleation of water was studied experimentally in this work using a thermal diffusion cloud chamber; droplets were counted by the photomultiplier method and helium was used as a carrier gas. The Nucleation rates range from 3×10−2 to 3×101 cm−3 s−1 and six isotherms from 295 to 320 K with step of 5 K are measured. The experimental setup and obtained data are mutually compared to our previous publication [Brus et al., J. Chem. Phys. 129, 174501 (2008)], where the droplets were counted using digital photography and image processing. The molecular content of the critical clusters was estimated from the slopes of experimental data. The measured isothermal dependencies of the Nucleation rate of water on the saturation ratio were compared with previously published data of others, several theoretical predictions, and the former Nucleation onset data. The aim of the present investigation was to show for the first time that Nucleation results can be quantitatively reproduced with two different exper...
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the Homogeneous Nucleation of 1 pentanol in a laminar flow diffusion chamber the effect of pressure and kind of carrier gas
Journal of Chemical Physics, 2008Co-Authors: David Brus, Y Viisanen, Vladimír Ždímal, A P Hyvarinen, Jan Wedekind, Jiři Smolik, Heikki LihavainenAbstract:The influence of total pressure and kind of carrier gas on Homogeneous Nucleation rates of 1-pentanol was investigated using experimental method of laminar flow diffusion chamber in this study. Two different carrier gases (helium and argon) were used in the total pressure range from 50to400kPa. Nucleation temperatures ranged from 265to290K for 1-pentanol-helium and from 265to285K for 1-pentanol-argon. Nucleation rates varied between 101 and 106cm−3s−1 for 1-pentanol-helium and between 102 and 105cm−3s−1 for 1-pentanol-argon. Both positive and slight negative pressure effects were observed depending on temperature and carrier gas. The trend of pressure effect was found similar for both carrier gases. Error analysis on thermodynamic properties was conducted, and the lowering of surface tension due to adsorption of argon on nucleated droplets was estimated. A quantitative overview of pressure effect is provided.
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the carrier gas pressure effect in a laminar flow diffusion chamber Homogeneous Nucleation of n butanol in helium
Journal of Chemical Physics, 2006Co-Authors: A P Hyvarinen, Y Viisanen, Vladimír Ždímal, David Brus, Markku Kulmala, Jiři Smolik, Heikki LihavainenAbstract:Homogeneous Nucleation rate isotherms of n-butanol+helium were measured in a laminar flow diffusion chamber at total pressures ranging from 50to210kPa to investigate the effect of carrier gas pressure on Nucleation. Nucleation temperatures ranged from 265to280K and the measured Nucleation rates were between 102 and 106cm−3s−1. The measured Nucleation rates decreased as a function of increasing pressure. The pressure effect was strongest at pressures below 100kPa. This negative carrier gas effect was also temperature dependent. At Nucleation temperature of 280K and at the same saturation ratio, the maximum deviation between Nucleation rates measured at 50 and 210kPa was about three orders of magnitude. At Nucleation temperature of 265K, the effect was negligible. Qualitatively the results resemble those measured in a thermal diffusion cloud chamber. Also the slopes of the isothermal Nucleation rates as a function of saturation ratio were different as a function of total pressure, 50kPa isotherms yielded th...
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Homogeneous Nucleation rate measurements of 1 propanol in helium the effect of carrier gas pressure
Journal of Chemical Physics, 2006Co-Authors: David Brus, Vladimír Ždímal, Frank StratmannAbstract:Kinetics of Homogeneous Nucleation in supersaturated vapor of 1-propanol was studied using an upward thermal diffusion cloud chamber. Helium was used as a noncondensable carrier gas and the influence of its pressure on observed Nucleation rates was investigated. The isothermal Nucleation rates were determined by a photographic method that is independent on any Nucleation theory. In this method, the trajectories of growing droplets are recorded using a charge coupled device camera and the distribution of local Nucleation rates is determined by image analysis. The Nucleation rate measurements of 1-propanol were carried out at four isotherms 260, 270, 280, and 290K. In addition, the pressure dependence was investigated on the isotherms 290K (50, 120, and 180kPa) and 280K (50 and 120kPa). The isotherm 270K was measured at 25kPa and the isotherm 260K at 20kPa. The experiments confirm the earlier observations from several thermal diffusion chamber investigations that the Homogeneous Nucleation rate of 1-propano...
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Homogeneous Nucleation rate measurements of 1 butanol in helium a comparative study of a thermal diffusion cloud chamber and a laminar flow diffusion chamber
Journal of Chemical Physics, 2005Co-Authors: David Brus, Vladimír Ždímal, A P Hyvarinen, Heikki LihavainenAbstract:Isothermal Homogeneous Nucleation rates of 1-butanol were measured both in a thermal diffusion cloud chamber and in a laminar flow diffusion chamber built recently at the Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, Prague, Czech Republic. The chosen system 1-butanol-helium can be studied reasonably well in both devices, in the overlapping range of temperatures. The results were compared with those found in the literature and those measured by Lihavainen in a laminar flow diffusion chamber of a similar design. The same isotherms measured with the thermal diffusion cloud chamber occur at highest saturation ratios of the three devices. Isotherms measured with the two laminar flow diffusion chambers are reasonably close together; the measurements by Lihavainen occur at lowest saturation ratios. The temperature dependences observed were similar in all three devices. The molecular content of critical clusters was calculated using the Nucleation theorem and compared wit...
Y Viisanen - One of the best experts on this subject based on the ideXlab platform.
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the Homogeneous Nucleation of 1 pentanol in a laminar flow diffusion chamber the effect of pressure and kind of carrier gas
Journal of Chemical Physics, 2008Co-Authors: David Brus, Y Viisanen, Vladimír Ždímal, A P Hyvarinen, Jan Wedekind, Jiři Smolik, Heikki LihavainenAbstract:The influence of total pressure and kind of carrier gas on Homogeneous Nucleation rates of 1-pentanol was investigated using experimental method of laminar flow diffusion chamber in this study. Two different carrier gases (helium and argon) were used in the total pressure range from 50to400kPa. Nucleation temperatures ranged from 265to290K for 1-pentanol-helium and from 265to285K for 1-pentanol-argon. Nucleation rates varied between 101 and 106cm−3s−1 for 1-pentanol-helium and between 102 and 105cm−3s−1 for 1-pentanol-argon. Both positive and slight negative pressure effects were observed depending on temperature and carrier gas. The trend of pressure effect was found similar for both carrier gases. Error analysis on thermodynamic properties was conducted, and the lowering of surface tension due to adsorption of argon on nucleated droplets was estimated. A quantitative overview of pressure effect is provided.
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the carrier gas pressure effect in a laminar flow diffusion chamber Homogeneous Nucleation of n butanol in helium
Journal of Chemical Physics, 2006Co-Authors: A P Hyvarinen, Y Viisanen, Vladimír Ždímal, David Brus, Markku Kulmala, Jiři Smolik, Heikki LihavainenAbstract:Homogeneous Nucleation rate isotherms of n-butanol+helium were measured in a laminar flow diffusion chamber at total pressures ranging from 50to210kPa to investigate the effect of carrier gas pressure on Nucleation. Nucleation temperatures ranged from 265to280K and the measured Nucleation rates were between 102 and 106cm−3s−1. The measured Nucleation rates decreased as a function of increasing pressure. The pressure effect was strongest at pressures below 100kPa. This negative carrier gas effect was also temperature dependent. At Nucleation temperature of 280K and at the same saturation ratio, the maximum deviation between Nucleation rates measured at 50 and 210kPa was about three orders of magnitude. At Nucleation temperature of 265K, the effect was negligible. Qualitatively the results resemble those measured in a thermal diffusion cloud chamber. Also the slopes of the isothermal Nucleation rates as a function of saturation ratio were different as a function of total pressure, 50kPa isotherms yielded th...
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a laminar flow diffusion chamber for Homogeneous Nucleation studies
Journal of Physical Chemistry B, 2001Co-Authors: Y ViisanenAbstract:A new version of laminar flow diffusion chamber was developed for unary Homogeneous Nucleation from vapor to liquid studies. The developed laminar flow diffusion chamber can quantitatively measure Nucleation rates as a function of saturation ratio and temperature. A numerical model was developed for calculations of temperature and saturation ratio profiles inside the laminar flow diffusion chamber. Several experiments were made to ensure the proper and reliable operation of the device and the numerical model. Nucleation rates of n-hexanol were measured using helium as a carrier gas from 265.0 to 295.0 K. The measured Nucleation rate range was from 103 to 107 cm-3 s-1. Temperature and saturation ratio dependencies were compared to the classical Nucleation theory. The saturation ratio dependency was well predicted by the theory. Results were compared to the measurements made by others. They were in reasonable agreement at the lower end of the temperature range of this study. The carrier gas effect was also ...
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Homogeneous Nucleation of n pentanol in a laminar flow diffusion chamber
Journal of Chemical Physics, 2001Co-Authors: Heikki Lihavainen, Y ViisanenAbstract:Nucleation rate isotherms of n-pentanol were measured in laminar flow diffusion chamber. n-pentanol was chosen for nucleating vapor and helium for carrier gas as a part of a world wide joint experiment on Homogeneous Nucleation. Experimental temperature range was from 260 to 290 K. Experimental Nucleation rate range was from 103 to 107 cm−3 s−1. The results were compared to the classical Nucleation theory and experimental data found in literature. Experimental results were three orders of magnitude higher than predicted by the theory. The difference was constant over the whole experimental range. The saturation ratio dependency of Nucleation rate was well predicted by the theory. The number of molecules in the critical clusters was quite consistent with the theory. The results were in reasonable agreement with data found in literature.
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measurement of the molecular content of binary nuclei ii use of the Nucleation rate surface for water ethanol
Journal of Chemical Physics, 1994Co-Authors: Y Viisanen, Aatto Laaksonen, Reinhard Strey, Markku KulmalaAbstract:In a preceding paper we determined the molecular contents of binary nuclei from Homogeneous Nucleation rate measurements studing ethanol–hexanol as a nearly ideal model system. Here we report the analogous measurements for the nonideal water–ethanol system known from previous investigations to display surface enrichment of ethanol in the nuclei. The Nucleation pulse technique applied allows accurate measurements of Homogeneous Nucleation rates in the range 105
Homogeneous Nucleation rates of mixed droplets in supersaturated water–ethanol vapor mixtures with argon as the carrier gas. The experiments were performed as functions of the water and ethanol gas phase activities, a1 and a2, respectively, ranging from pure water to pure ethanol with ten intermediate activity ratios at T=260 K. The experimental data shape a Nucleation rate surface in three‐dimensional J–a1–a2 space from which the critical activities for a rate of Jc=107 cm−3 s−1 were determined. The critical activi...
A P Hyvarinen - One of the best experts on this subject based on the ideXlab platform.
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the Homogeneous Nucleation of 1 pentanol in a laminar flow diffusion chamber the effect of pressure and kind of carrier gas
Journal of Chemical Physics, 2008Co-Authors: David Brus, Y Viisanen, Vladimír Ždímal, A P Hyvarinen, Jan Wedekind, Jiři Smolik, Heikki LihavainenAbstract:The influence of total pressure and kind of carrier gas on Homogeneous Nucleation rates of 1-pentanol was investigated using experimental method of laminar flow diffusion chamber in this study. Two different carrier gases (helium and argon) were used in the total pressure range from 50to400kPa. Nucleation temperatures ranged from 265to290K for 1-pentanol-helium and from 265to285K for 1-pentanol-argon. Nucleation rates varied between 101 and 106cm−3s−1 for 1-pentanol-helium and between 102 and 105cm−3s−1 for 1-pentanol-argon. Both positive and slight negative pressure effects were observed depending on temperature and carrier gas. The trend of pressure effect was found similar for both carrier gases. Error analysis on thermodynamic properties was conducted, and the lowering of surface tension due to adsorption of argon on nucleated droplets was estimated. A quantitative overview of pressure effect is provided.
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the carrier gas pressure effect in a laminar flow diffusion chamber Homogeneous Nucleation of n butanol in helium
Journal of Chemical Physics, 2006Co-Authors: A P Hyvarinen, Y Viisanen, Vladimír Ždímal, David Brus, Markku Kulmala, Jiři Smolik, Heikki LihavainenAbstract:Homogeneous Nucleation rate isotherms of n-butanol+helium were measured in a laminar flow diffusion chamber at total pressures ranging from 50to210kPa to investigate the effect of carrier gas pressure on Nucleation. Nucleation temperatures ranged from 265to280K and the measured Nucleation rates were between 102 and 106cm−3s−1. The measured Nucleation rates decreased as a function of increasing pressure. The pressure effect was strongest at pressures below 100kPa. This negative carrier gas effect was also temperature dependent. At Nucleation temperature of 280K and at the same saturation ratio, the maximum deviation between Nucleation rates measured at 50 and 210kPa was about three orders of magnitude. At Nucleation temperature of 265K, the effect was negligible. Qualitatively the results resemble those measured in a thermal diffusion cloud chamber. Also the slopes of the isothermal Nucleation rates as a function of saturation ratio were different as a function of total pressure, 50kPa isotherms yielded th...
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Homogeneous Nucleation rate measurements of 1 butanol in helium a comparative study of a thermal diffusion cloud chamber and a laminar flow diffusion chamber
Journal of Chemical Physics, 2005Co-Authors: David Brus, Vladimír Ždímal, A P Hyvarinen, Heikki LihavainenAbstract:Isothermal Homogeneous Nucleation rates of 1-butanol were measured both in a thermal diffusion cloud chamber and in a laminar flow diffusion chamber built recently at the Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, Prague, Czech Republic. The chosen system 1-butanol-helium can be studied reasonably well in both devices, in the overlapping range of temperatures. The results were compared with those found in the literature and those measured by Lihavainen in a laminar flow diffusion chamber of a similar design. The same isotherms measured with the thermal diffusion cloud chamber occur at highest saturation ratios of the three devices. Isotherms measured with the two laminar flow diffusion chambers are reasonably close together; the measurements by Lihavainen occur at lowest saturation ratios. The temperature dependences observed were similar in all three devices. The molecular content of critical clusters was calculated using the Nucleation theorem and compared wit...
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Homogeneous Nucleation rate measurements of 1 butanol in helium a comparative study of a thermal diffusion cloud chamber and a laminar flow diffusion chamber
Journal of Chemical Physics, 2005Co-Authors: David Brus, Vladimír Ždímal, A P Hyvarinen, Heikki LihavainenAbstract:Isothermal Homogeneous Nucleation rates of 1-butanol were measured both in a thermal diffusion cloud chamber and in a laminar flow diffusion chamber built recently at the Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, Prague, Czech Republic. The chosen system 1-butanol-helium can be studied reasonably well in both devices, in the overlapping range of temperatures. The results were compared with those found in the literature and those measured by Lihavainen in a laminar flow diffusion chamber of a similar design. The same isotherms measured with the thermal diffusion cloud chamber occur at highest saturation ratios of the three devices. Isotherms measured with the two laminar flow diffusion chambers are reasonably close together; the measurements by Lihavainen occur at lowest saturation ratios. The temperature dependences observed were similar in all three devices. The molecular content of critical clusters was calculated using the Nucleation theorem and compared with the Kelvin equation. Both laminar flow diffusion chambers provided very similar sizes slightly above the Kelvin equation, whereas the thermal diffusion cloud chamber suggests critical cluster sizes significantly smaller. The results found elsewhere in the literature were in reasonable agreement with our results.