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Heikki Lihavainen - One of the best experts on this subject based on the ideXlab platform.
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Homogenous Nucleation rates of n propanol measured in the laminar flow diffusion chamber at different total pressures
Journal of Chemical Physics, 2014Co-Authors: Hanna Gorke, K. Neitola, Heikki Lihavainen, A P Hyvarinen, Judith Wolk, R Strey, D BrusAbstract:Nucleation rates of n-propanol were investigated in the Laminar Flow Diffusion Chamber. Nucleation temperatures between 270 and 300 K and rates between 100 and 106 cm−3 s−1 were achieved. Since earlier measurements of n-butanol and n‑pentanol suggest a dependence of Nucleation rates on carrier gas pressure, similar conditions were adjusted for these measurements. The obtained data fit well to results available from literature. A small positive pressure effect was found which strengthen the assumption that this effect is attributed to the carbon chain length of the n-alcohol [D. Brus, A. P. Hyvarinen, J. Wedekind, Y. Viisanen, M. Kulmala, V. Ždimal, J. Smolik, and H. Lihavainen, J. Chem. Phys. 128, 134312 (2008)] and might be less intensive for substances in the homologous series with higher equilibrium vapor pressure. A comparison with the theoretical approach by Wedekind et al. [Phys. Rev. Lett. 101, 12 (2008)] shows that the effect goes in the same direction but that the intensity is much stronger in ex...
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Homogenous Nucleation of sulfuric acid and water at close to atmospherically relevant conditions
Atmospheric Chemistry and Physics, 2011Co-Authors: Dagmar Brus, A. P. Hyv̈arinen, Jenni Vanhanen, Tuukka Petaja, Pauli Paasonen, K. Neitola, Mikko Sipilä, Markku Kulmala, Heikki LihavainenAbstract:In this study the homogeneous Nucleation rates in the system of sulfuric acid and water were measured by using a flow tube technique. The goal was to directly compare particle formation rates obtained from atmospheric measurements with Nucleation rates of freshly nucleated particles measured with particle size magnifier (PSM) which has detection efficiency of unity for particles having mobility diameter of 1.5 nm. The gas phase sulfuric acid concentration in this study was measured with the chemical ionization mass spectrometer (CIMS), commonly used in field measurements. The wall losses of sulfuric acid were estimated from measured concentration profiles along the flow tube. The initial concentrations of sulfuric acid estimated from loss measurements ranged from 10(8) to 3 x 10(9) molecules cm(-3). The Nucleation rates obtained in this study cover about three orders of magnitude from 10(-1) to 10(2) cm(-3) s(-1) for commercial ultrafine condensation particle counter (UCPC) TSI model 3025A and from 10(1) to 10(4) cm(-3) s(-1) for PSM. The Nucleation rates and the slopes (dlnJ/dln [H(2)SO(4)]) show satisfactory agreement when compared to empirical kinetic and activation models and the latest atmospheric Nucleation data. To the best of our knowledge, this is the first experimental work providing temperature dependent Nucleation rate measurements using a high efficiency particle counter with a cutoff-size of 1.5 nm together with direct measurements of gas phase sulfuric acid concentration.
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binary Homogenous Nucleation of sulfuric acid and water mixture experimental device and setup
2007Co-Authors: David Brus, Y Viisanen, Heikki Lihavainen, Anttipekka Hyvarinen, Markku KulmalaAbstract:New particle formation in the atmosphere has received considerable attention lately both from atmospheric scientists and aerosol researchers. Atmospheric new particles have been observed to form by self-condensing or nucleating homogeneously in events lasting a couple of hours nearly all around the world (Kulmala et al., 2004). The first step of new particle formation or any first order phase transition is Nucleation. It has been calculated that in the atmosphere the equilibrium vapor pressure of sulfuric acid is low enough for it to be a likely candidate to nucleate homogeneously, (e.g. Seinfeld and Pandis, 1998). All recent experiments on homogeneous sulfuric acid and water Nucleation have relied on a flow-based measurement technique (e.g. Wyslouzil et al.1991, Viisanen et al., 1997, Ball et al., 1999, Zhang et al., 2004 and Berndt et al., 2006). In general the results are in fair agreement with each other, although somehow dependent on the method of generating the sulfuric acid vapor. A New laminar flow chamber built recently in Finnish Meteorological Institute is presented here. It is designed for homogeneous Nucleation experiments of binary and ternary compounds such as sulfuric acid and water. The laminar flow chamber is positioned vertically and experimental setup consists of an atomizer, a furnace, a mixing unit, a Nucleation chamber and measurement unit. A known amount of studied solution is introduced to furnace with HPLC Pump through a ruby micro-orifice (20 μm). The dispersion is then vaporized in a Pyrex glass tube wrapped with resistant heating wires. The furnace temperature is kept at 380 °C, and the temperature of vapor inside furnace is 235 °C. After furnace, the vapor is filtered with Teflon filter, introduced to mixing unite and cooled by turbulent mixing with particle free air to 60 °C. The vapor gas mixture is then cooled to wanted Nucleation temperature in nucleating chamber which is kept at constant temperature with two liquid circulating baths. The Nucleation chamber is made of stainless steel and its whole length is 200 cm. Temperature of the stream is registered along the Nucleation chamber using six PT100 probes. For Nucleation at room temperature, 25 °C is achieved at a distance approximately 115 cm from the mixing unit. The measured temperature profile is shown in Fig 1.
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homogeneous Nucleation of n pentanol in a laminar flow diffusion chamber
NUCLEATION AND ATMOSPHERIC AEROSOLS 2000: 15th International Conference, 2001Co-Authors: Heikki Lihavainen, Y Viisanen, Markku KulmalaAbstract:As a contribution to the Joint Experiment on Homogenous Nucleation, a version of a laminar flow diffusion chamber was developed for Nucleation rate measurements. The design and operational characteristics of the chamber will be presented. Homogenous Nucleation rates of n-pentanol were measured as a function of saturation ratio in the temperature range between 260 K and 290 K. The results were compared to the classical Nucleation theory. The experimental results were three orders of magnitudes higher than the theoretical predictions. The difference was almost constant over the whole temperature range. The results were compared with results from other experimental devices, they were in good agreement at lower temperatures.
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Homogenous Nucleation of n-butanol in laminar flow diffusion chamber
Journal of Aerosol Science, 2000Co-Authors: Heikki Lihavainen, Y ViisanenAbstract:In this study laminar flow diffusion chamber was developed to measure homogeneous Nucleation rates as a function of saturation and temperature. n-Butanol was chosen for nucleating vapor because its thermodynamic properties are well known.
Y Viisanen - One of the best experts on this subject based on the ideXlab platform.
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binary Homogenous Nucleation of sulfuric acid and water mixture experimental device and setup
2007Co-Authors: David Brus, Y Viisanen, Heikki Lihavainen, Anttipekka Hyvarinen, Markku KulmalaAbstract:New particle formation in the atmosphere has received considerable attention lately both from atmospheric scientists and aerosol researchers. Atmospheric new particles have been observed to form by self-condensing or nucleating homogeneously in events lasting a couple of hours nearly all around the world (Kulmala et al., 2004). The first step of new particle formation or any first order phase transition is Nucleation. It has been calculated that in the atmosphere the equilibrium vapor pressure of sulfuric acid is low enough for it to be a likely candidate to nucleate homogeneously, (e.g. Seinfeld and Pandis, 1998). All recent experiments on homogeneous sulfuric acid and water Nucleation have relied on a flow-based measurement technique (e.g. Wyslouzil et al.1991, Viisanen et al., 1997, Ball et al., 1999, Zhang et al., 2004 and Berndt et al., 2006). In general the results are in fair agreement with each other, although somehow dependent on the method of generating the sulfuric acid vapor. A New laminar flow chamber built recently in Finnish Meteorological Institute is presented here. It is designed for homogeneous Nucleation experiments of binary and ternary compounds such as sulfuric acid and water. The laminar flow chamber is positioned vertically and experimental setup consists of an atomizer, a furnace, a mixing unit, a Nucleation chamber and measurement unit. A known amount of studied solution is introduced to furnace with HPLC Pump through a ruby micro-orifice (20 μm). The dispersion is then vaporized in a Pyrex glass tube wrapped with resistant heating wires. The furnace temperature is kept at 380 °C, and the temperature of vapor inside furnace is 235 °C. After furnace, the vapor is filtered with Teflon filter, introduced to mixing unite and cooled by turbulent mixing with particle free air to 60 °C. The vapor gas mixture is then cooled to wanted Nucleation temperature in nucleating chamber which is kept at constant temperature with two liquid circulating baths. The Nucleation chamber is made of stainless steel and its whole length is 200 cm. Temperature of the stream is registered along the Nucleation chamber using six PT100 probes. For Nucleation at room temperature, 25 °C is achieved at a distance approximately 115 cm from the mixing unit. The measured temperature profile is shown in Fig 1.
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homogeneous Nucleation of n pentanol in a laminar flow diffusion chamber
NUCLEATION AND ATMOSPHERIC AEROSOLS 2000: 15th International Conference, 2001Co-Authors: Heikki Lihavainen, Y Viisanen, Markku KulmalaAbstract:As a contribution to the Joint Experiment on Homogenous Nucleation, a version of a laminar flow diffusion chamber was developed for Nucleation rate measurements. The design and operational characteristics of the chamber will be presented. Homogenous Nucleation rates of n-pentanol were measured as a function of saturation ratio in the temperature range between 260 K and 290 K. The results were compared to the classical Nucleation theory. The experimental results were three orders of magnitudes higher than the theoretical predictions. The difference was almost constant over the whole temperature range. The results were compared with results from other experimental devices, they were in good agreement at lower temperatures.
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Homogenous Nucleation of n-butanol in laminar flow diffusion chamber
Journal of Aerosol Science, 2000Co-Authors: Heikki Lihavainen, Y ViisanenAbstract:In this study laminar flow diffusion chamber was developed to measure homogeneous Nucleation rates as a function of saturation and temperature. n-Butanol was chosen for nucleating vapor because its thermodynamic properties are well known.
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a theoretical study of binary Homogenous Nucleation of water ammonium chloride particles in the atmosphere
Journal of Aerosol Science, 1997Co-Authors: P Korhonen, Markku Kulmala, Y ViisanenAbstract:Abstract Studies of the Nucleation of new particles in the atmosphere are usually concentrated on the formation of sulfuric acid particles. However, there exist also other trace gas species with the Nucleation capability in the atmosphere. In this paper the formation of water-ammonium chloride particles via Homogenous heteromolecular Nucleation in the atmospheric conditions is studied by using classical Nucleation theory. This study is focused especially at the high relative humidities (90–99%), that can be found in the atmosphere during cloud or fog processes. The Gibbs free energy for the formation of a stable cluster is found to be insensitive to the variations in relative humidity. Instead, according to the results the Nucleation rate is dependent on relative humidity, although the influence of relative humidity on the Nucleation rate is relatively weak at the studied relative humidity range. The significant Nucleation of stable water-ammonium chloride clusters via the studied path is concluded to be possible only in the polluted atmosphere during cloud processes. In the clean (for example remote sea) areas the significant Nucleation of aqueous ammonium chloride particles is found to be highly impropable.
Masao Iwamatsu - One of the best experts on this subject based on the ideXlab platform.
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minimum free energy path of Homogenous Nucleation from the phase field equation
Journal of Chemical Physics, 2009Co-Authors: Masao IwamatsuAbstract:The minimum free-energy path (MFEP) is the most probable route of the Nucleation process on the multidimensional free-energy surface. In this study, the phase-field equation is used as a mathematical tool to deduce the MFEP of homogeneous Nucleation. We use a simple square-gradient free-energy functional with a quartic local free-energy function as an example and study the time evolution of a single nucleus placed within a metastable environment. The time integration of the phase-field equation is performed using the numerically efficient cell-dynamics method. By monitoring the evolution of the size of the nucleus and the free energy of the system simultaneously, we can easily deduce the free-energy barrier as a function of the size of the sub- and the supercritical nucleus along the MFEP.
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minimum free energy path of Homogenous Nucleation from the phase field equation
arXiv: Materials Science, 2009Co-Authors: Masao IwamatsuAbstract:The minimum free-energy path (MFEP) is the most probable route of the Nucleation process on the multidimensional free-energy surface. In this study, the phase-field equation is used as a mathematical tool to deduce the minimum free-energy path (MFEP) of homogeneous Nucleation. We use a simple square-gradient free-energy functional with a quartic local free-energy function as an example and study the time evolution of a single nucleus placed within a metastable environment. The time integration of the phase-field equation is performed using the numerically efficient cell-dynamics method. By monitoring the evolution of the size of the nucleus and the free energy of the system simultaneously, we can easily deduce the free-energy barrier as a function of the size of the sub- and the super-critical nucleus along the MFEP.
Markku Kulmala - One of the best experts on this subject based on the ideXlab platform.
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Homogenous Nucleation of sulfuric acid and water at close to atmospherically relevant conditions
Atmospheric Chemistry and Physics, 2011Co-Authors: Dagmar Brus, A. P. Hyv̈arinen, Jenni Vanhanen, Tuukka Petaja, Pauli Paasonen, K. Neitola, Mikko Sipilä, Markku Kulmala, Heikki LihavainenAbstract:In this study the homogeneous Nucleation rates in the system of sulfuric acid and water were measured by using a flow tube technique. The goal was to directly compare particle formation rates obtained from atmospheric measurements with Nucleation rates of freshly nucleated particles measured with particle size magnifier (PSM) which has detection efficiency of unity for particles having mobility diameter of 1.5 nm. The gas phase sulfuric acid concentration in this study was measured with the chemical ionization mass spectrometer (CIMS), commonly used in field measurements. The wall losses of sulfuric acid were estimated from measured concentration profiles along the flow tube. The initial concentrations of sulfuric acid estimated from loss measurements ranged from 10(8) to 3 x 10(9) molecules cm(-3). The Nucleation rates obtained in this study cover about three orders of magnitude from 10(-1) to 10(2) cm(-3) s(-1) for commercial ultrafine condensation particle counter (UCPC) TSI model 3025A and from 10(1) to 10(4) cm(-3) s(-1) for PSM. The Nucleation rates and the slopes (dlnJ/dln [H(2)SO(4)]) show satisfactory agreement when compared to empirical kinetic and activation models and the latest atmospheric Nucleation data. To the best of our knowledge, this is the first experimental work providing temperature dependent Nucleation rate measurements using a high efficiency particle counter with a cutoff-size of 1.5 nm together with direct measurements of gas phase sulfuric acid concentration.
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binary Homogenous Nucleation of sulfuric acid and water mixture experimental device and setup
2007Co-Authors: David Brus, Y Viisanen, Heikki Lihavainen, Anttipekka Hyvarinen, Markku KulmalaAbstract:New particle formation in the atmosphere has received considerable attention lately both from atmospheric scientists and aerosol researchers. Atmospheric new particles have been observed to form by self-condensing or nucleating homogeneously in events lasting a couple of hours nearly all around the world (Kulmala et al., 2004). The first step of new particle formation or any first order phase transition is Nucleation. It has been calculated that in the atmosphere the equilibrium vapor pressure of sulfuric acid is low enough for it to be a likely candidate to nucleate homogeneously, (e.g. Seinfeld and Pandis, 1998). All recent experiments on homogeneous sulfuric acid and water Nucleation have relied on a flow-based measurement technique (e.g. Wyslouzil et al.1991, Viisanen et al., 1997, Ball et al., 1999, Zhang et al., 2004 and Berndt et al., 2006). In general the results are in fair agreement with each other, although somehow dependent on the method of generating the sulfuric acid vapor. A New laminar flow chamber built recently in Finnish Meteorological Institute is presented here. It is designed for homogeneous Nucleation experiments of binary and ternary compounds such as sulfuric acid and water. The laminar flow chamber is positioned vertically and experimental setup consists of an atomizer, a furnace, a mixing unit, a Nucleation chamber and measurement unit. A known amount of studied solution is introduced to furnace with HPLC Pump through a ruby micro-orifice (20 μm). The dispersion is then vaporized in a Pyrex glass tube wrapped with resistant heating wires. The furnace temperature is kept at 380 °C, and the temperature of vapor inside furnace is 235 °C. After furnace, the vapor is filtered with Teflon filter, introduced to mixing unite and cooled by turbulent mixing with particle free air to 60 °C. The vapor gas mixture is then cooled to wanted Nucleation temperature in nucleating chamber which is kept at constant temperature with two liquid circulating baths. The Nucleation chamber is made of stainless steel and its whole length is 200 cm. Temperature of the stream is registered along the Nucleation chamber using six PT100 probes. For Nucleation at room temperature, 25 °C is achieved at a distance approximately 115 cm from the mixing unit. The measured temperature profile is shown in Fig 1.
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homogeneous Nucleation of n pentanol in a laminar flow diffusion chamber
NUCLEATION AND ATMOSPHERIC AEROSOLS 2000: 15th International Conference, 2001Co-Authors: Heikki Lihavainen, Y Viisanen, Markku KulmalaAbstract:As a contribution to the Joint Experiment on Homogenous Nucleation, a version of a laminar flow diffusion chamber was developed for Nucleation rate measurements. The design and operational characteristics of the chamber will be presented. Homogenous Nucleation rates of n-pentanol were measured as a function of saturation ratio in the temperature range between 260 K and 290 K. The results were compared to the classical Nucleation theory. The experimental results were three orders of magnitudes higher than the theoretical predictions. The difference was almost constant over the whole temperature range. The results were compared with results from other experimental devices, they were in good agreement at lower temperatures.
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a theoretical study of binary Homogenous Nucleation of water ammonium chloride particles in the atmosphere
Journal of Aerosol Science, 1997Co-Authors: P Korhonen, Markku Kulmala, Y ViisanenAbstract:Abstract Studies of the Nucleation of new particles in the atmosphere are usually concentrated on the formation of sulfuric acid particles. However, there exist also other trace gas species with the Nucleation capability in the atmosphere. In this paper the formation of water-ammonium chloride particles via Homogenous heteromolecular Nucleation in the atmospheric conditions is studied by using classical Nucleation theory. This study is focused especially at the high relative humidities (90–99%), that can be found in the atmosphere during cloud or fog processes. The Gibbs free energy for the formation of a stable cluster is found to be insensitive to the variations in relative humidity. Instead, according to the results the Nucleation rate is dependent on relative humidity, although the influence of relative humidity on the Nucleation rate is relatively weak at the studied relative humidity range. The significant Nucleation of stable water-ammonium chloride clusters via the studied path is concluded to be possible only in the polluted atmosphere during cloud processes. In the clean (for example remote sea) areas the significant Nucleation of aqueous ammonium chloride particles is found to be highly impropable.
Katrin Schaber - One of the best experts on this subject based on the ideXlab platform.
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Effect of a gas-gas-heater on H2SO4 aerosol formation: implications for mist formation in amine based carbon capture
International Journal of Greenhouse Gas Control, 2015Co-Authors: Jan Mertens, Purvil Khakharia, Earl Goetheer, Bernd Schallert, R. Bruns, Nathalie Faniel, W. Albrecht, Julien Blondeau, Katrin SchaberAbstract:This study is to our knowledge the first to describe the effect of a Gas-Gas Heater (GGH) of a coal fired power plant's has on (i) the H2SO4 concentration and (ii) the particle/aerosol number concentration and particle size distribution present in the flue gas. In the absence of a GGH, Homogenous Nucleation takes places inside the Wet Flue Gas Desulphurisation (WFGD) converting the gaseous H2SO4 into aerosol H2SO4. This leads to a high aerosol number concentration behind the WFGD with 80% of the aerosols being smaller than 0.02 μm. This implies that an amine based carbon capture (CC) installation treating this flue gas can suffer from amine mist formation due to the high amount of available nuclei (i.e., H2SO4 aerosols) resulting in high amine emissions. In contrast, in the presence of a GGH not only 70% of the H2SO4 is removed from the flue gas (measured at the Nijmegen powerplant), but also Homogenous Nucleation in the WFGD is prevented resulting in low particle number concentrations. The flue gas leaving the GGH will not create any mist formation issues in an amine based CC installation due to the low amount of nuclei present in the flue gas. It is not the reduction in H2SO4 concentration by 70% inside the GGH as such that prevents mist formation but absence of H2SO4 in its aerosol form. These results are most likely quite widely transformable to other power plants that burn low sulfur coal i.e., around 0.7 weight%. This information will serve future pilot and demo CC installation around the world; in particular when retrofitted on power plants that have a GGH.