Formation and evolution of ultrafine particles produced by radiolysis and photolysis

Madelaine, G.; Perrin, M.L.; Renoux, A.

doi:10.1029/jc085ic12p07471

Cited by 5 publications

(3 citation statements)

References 7 publications

(9 reference statements)

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“…A higher value of 0.045 cm2 s-' was found at a higher flow rate of 3.5 L min-' . These ultrafine particles have high mobility and can coagulate rapidly to large clusters (Madelaine et al 1980). The parabolic flow velocity profile will not be fully developed before 22nRn injection if the flow rate exceeds 2 L min-', and the entrance effect may lead to an inaccurate result.…”

Section: Discussionmentioning

confidence: 99%

Experimental Measurements of the Diffusion Coefficient of 212Pb

Newton²,

Cheng³

et al. 1989

Health Physics

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Knowledge of the diffusion coefficient of Rn progeny is necessary for assessing the radiation exposure resulting from exposure to Rn and its progeny. The diffusion coefficient for 220Rn progeny was determined in ambient air by two independent methods, measuring deposition using a cylindrical tube or screens. A sampling train consisting of a diffusion tube and a screen-type diffusion battery was used for the experimental study. A range of flow rates and relative humidities was investigated. For 35% less than or equal to RH less than or equal to 85%, results from the two systems agree with each other. The diffusion coefficient of 212Pb was 0.036 +/- 0.002 cm2 s-1 and 0.037 +/- 0.004 cm2 s-1 for the tube and screen penetration methods, respectively. In low humidity air (RH less than 30%), a linear relationship between the diffusion coefficient of 212Pb and relative humidity was observed. The observed diffusion coefficient is strongly affected by the amount of material agglomerated onto the 212Pb atom. Further studies on the effects of trace gases and organics are required to fully understand the results.

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Section: Discussionmentioning

confidence: 99%

Experimental Measurements of the Diffusion Coefficient of 212Pb

Newton²,

Cheng³

et al. 1989

Health Physics

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“…Laboratory experiments demonstrated that alpha decay of short-lived actinon ( 219 Rn, half-life of 3.9 s) had a well pronounced influence on the aerosol particle nucleation and its evolution in time [20]. Repeated injection of 219 Rn resulted in formation of the bimodal aerosol particle size distribution.…”

Section: Introductionmentioning

confidence: 99%

“…Repeated injection of 219 Rn resulted in formation of the bimodal aerosol particle size distribution. Madelaine et al [20] considered coagulation of newly nucleated aerosol particles as a main process governing the aerosol particle growth toward larger diameters. Winklymayr et al [21] studied radiolytically induced aerosol nucleation processes in a N 2 -SO 2 -H 2 O mixture using 241 Am as an ionization source.…”

Section: Introductionmentioning

confidence: 99%

Impact of krypton-85 beta radiation on aerosol particle formation and transformation

Ulevičius¹,

Butkus²,

Plauškaitė³

et al. 2009

Lithuanian J. Phys.

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In this study the effect of the air ionization by 85 Kr beta radiation on the new particle formation and evolution of aerosol particle size distribution in the experimental chamber was investigated. During the experiments the interaction between air ionization and gas-to-particle conversion processes was distinctly observed. Results showed that the amplitude of the ionic current was dependent both on the chemical impurity concentration and the ionization source activity. Calculated values of parameters (growth and formation rates) of the particle nucleation process were larger when in the experimental chamber concentrations of SO2 and 85 Kr were higher. The growth rate values (42.1 and 45.3 nm/h) were by one order of magnitude higher than the environmental ones (1.2-9.9 nm/h at the Preila station, Lithuania). Experimental data showed that after injection of high SO2 and 85 Kr concentrations in the chamber during the 20 min interval nanometre-size particles created by nucleation were produced in large amounts. Thus, a larger amount of SO2 significantly influenced the formation of new particles. During the first 5 min the concentration of 10 nm particles increased by 3 orders of magnitude with the formation rate of 7.47 cm −3 s −1 . The formation rate of 0.06 cm −3 s −1 in the experiment with the average ambient SO2 concentration (2-3 µg/m3 ) was analogous to the environmental one (0.14 cm −3 s −1 ). The coagulation sink (CoagS 1,2,3 ) was higher in the experiment with the ambient SO2 concentration and resulted in the lower concentration of particles. The smaller values of the coagulation sink at the higher concentration of SO2 gas have shown that these nano-particles in the air could persist for a longer time, probably in a stable size due to the ion charge.

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Tropospheric Aerosol Formation: Processes, Observations and Simulations

Turco

2000

Chemistry and Radiation Changes in the Ozone Layer

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Formation and evolution of ultrafine particles produced by radiolysis and photolysis

Cited by 5 publications

References 7 publications

Experimental Measurements of the Diffusion Coefficient of 212Pb

Experimental Measurements of the Diffusion Coefficient of 212Pb

Impact of krypton-85 beta radiation on aerosol particle formation and transformation

Tropospheric Aerosol Formation: Processes, Observations and Simulations

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