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Volumn 14, Issue 10, 2014, Pages 5153-5181

Modeling kinetic partitioning of secondary organic aerosol and size distribution dynamics: Representing effects of volatility, phase state, and particle-phase reaction

Author keywords

[No Author keywords available]

Indexed keywords

AEROSOL; AEROSOL FORMATION; ATMOSPHERIC MODELING; DIFFUSION; PARTICLE SIZE; PARTITIONING; PHYSICOCHEMICAL PROPERTY; REACTION KINETICS; REACTION RATE; SIZE DISTRIBUTION; TIMESCALE;

EID: 84901443971     PISSN: 16807316     EISSN: 16807324     Source Type: Journal    
DOI: 10.5194/acp-14-5153-2014     Document Type: Article
Times cited : (121)

References (66)
  • 1
    • 84873303196 scopus 로고    scopus 로고
    • Experimental determination of chemical diffusion within secondary organic aerosol particles
    • Abramson, E., Imre, D., Beránek, J., Wilson, J., and Zelenyuk, A.: Experimental determination of chemical diffusion within secondary organic aerosol particles, Phys. Chem. Chem. Phys., 15, 2983-2991, 2013.
    • (2013) Phys. Chem. Chem. Phys. , vol.15 , pp. 2983-2991
    • Abramson, E.1    Imre, D.2    Beránek, J.3    Wilson, J.4    Zelenyuk, A.5
  • 2
    • 85010186810 scopus 로고
    • Mass Transfer with Chemical Reaction
    • New York
    • Astarita, G.: Mass Transfer with Chemical Reaction. Elsevier, New York, 1967.
    • (1967) Elsevier
    • Astarita, G.1
  • 3
    • 0003944113 scopus 로고    scopus 로고
    • Transport Phenomena
    • revised 2nd Edn.. John Wiley & Hoboken, NJ
    • Bird, R. B., Stewart, W. E., and Lightfoot, E. N.: Transport Phenomena (revised 2nd Edn.). John Wiley & Sons, Inc., Hoboken, NJ, 2007.
    • (2007) Sons, Inc.
    • Bird, R.B.1    Stewart, W.E.2    Lightfoot, E.N.3
  • 4
    • 84880440894 scopus 로고    scopus 로고
    • Kinetic regimes and limiting cases of gas uptake and heterogeneous reactions in atmospheric aerosols and clouds:A general classification scheme
    • doi:10.5194/acp-13-6663-2013
    • Berkemeier, T., Huisman, A. J., Ammann, M., Shiraiwa, M., Koop, T., and Pöschl, U.: Kinetic regimes and limiting cases of gas uptake and heterogeneous reactions in atmospheric aerosols and clouds: a general classification scheme, Atmos. Chem. Phys., 13, 6663-6686, doi:10.5194/acp-13- 6663-2013, 2013.
    • (2013) Atmos. Chem. Phys. , vol.13 , pp. 6663-6686
    • Berkemeier, T.1    Huisman, A.J.2    Ammann, M.3    Shiraiwa, M.4    Koop, T.5    Pöschl, U.6
  • 5
    • 0031543438 scopus 로고    scopus 로고
    • H.: Mathematical model for gas-particle partitioning of secondary organic aerosols
    • Bowman, F. M., Odum, J. R., and Seinfeld, J. H.: Mathematical model for gas-particle partitioning of secondary organic aerosols, Atmos. Environ., 31, 3921-3931, 1997.
    • (1997) Atmos. Environ. , vol.31 , pp. 3921-3931
    • Bowman, F.M.1    Odum, J.R.2    Seinfeld, J.3
  • 6
    • 84880782027 scopus 로고    scopus 로고
    • Particle partitioning potential of organic compounds is highest in the Eastern US and driven by anthropogenic water
    • doi:10.5194/acp-13-10203-2013
    • Carlton, A. G. and Turpin, B. J.: Particle partitioning potential of organic compounds is highest in the Eastern US and driven by anthropogenic water, Atmos. Chem. Phys., 13, 10203-10214, doi:10.5194/acp-13-10203-2013, 2013.
    • (2013) Atmos. Chem. Phys. , vol.13 , pp. 10203-10214
    • Carlton, A.G.1    Turpin, B.J.2
  • 7
    • 57449092717 scopus 로고    scopus 로고
    • CMAQ model performance enhanced when in-cloud secondary organic aerosol is included: Comparisons of organic carbon predictions with measurements
    • Carlton, A. G., Turpin, B. I., Altieri, K. E., Seitzinger, S. P., Mathur, R., Roselle, S. J., and Weber, R. J.: CMAQ model performance enhanced when in-cloud secondary organic aerosol is included: comparisons of organic carbon predictions with measurements, Environ. Sci. Technol., 42, 8798-8802, 2008.
    • (2008) Environ. Sci. Technol. , vol.42 , pp. 8798-8802
    • Carlton, A.G.1    Turpin, B.I.2    Altieri, K.E.3    Seitzinger, S.P.4    Mathur, R.5    Roselle, S.J.6    Weber, R.J.7
  • 9
    • 0004020231 scopus 로고
    • 2nd ed., Oxford University Press Inc., New York
    • Crank, J.: The Mathematics of Diffusion, 2nd ed., Oxford University Press Inc., New York, 1975.
    • (1975) The Mathematics of Diffusion
    • Crank, J.1
  • 10
    • 0000638818 scopus 로고
    • Absorption and simultaneous diffusion and chemical reaction into particles of various shapes and into falling drops
    • Danckwerts, P. V.: Absorption and simultaneous diffusion and chemical reaction into particles of various shapes and into falling drops, Trans. Faraday Soc., 47, 1014-1023, 1951.
    • (1951) Trans. Faraday Soc. , vol.47 , pp. 1014-1023
    • Danckwerts, P.V.1
  • 11
    • 80051717402 scopus 로고    scopus 로고
    • Theoretical constraints on pure vapor-pressure driven condensation of organics to ultrafine particles
    • doi:10.1029/2011GL048115
    • Donahue, N. M., Trump, E. R., Pierce, J. R., and Riipinen, I.: Theoretical constraints on pure vapor-pressure driven condensation of organics to ultrafine particles, Geophys. Res. Lett., 38, L16801, doi:10.1029/ 2011GL048115, 2011.
    • (2011) Geophys. Res. Lett. , vol.38
    • Donahue, N.M.1    Trump, E.R.2    Pierce, J.R.3    Riipinen, I.4
  • 12
    • 0002728857 scopus 로고
    • Heterogeneous reactions: Analysis, examples, and reactor design
    • Wiley-Interscience, New York
    • Doraiswamy, L. K. and Sharma, M. M.: Heterogeneous Reactions: Analysis, Examples, and Reactor Design, Vol. 2.: Fluid-Fluid-Solid Reactions. Wiley-Interscience, New York, 1984.
    • (1984) Fluid-Fluid-Solid Reactions , vol.2
    • Doraiswamy, L.K.1    Sharma, M.M.2
  • 14
    • 77956319744 scopus 로고    scopus 로고
    • Glyoxal processing by aerosol multiphase chemistry: Towards a kinetic modeling framework of secondary organic aerosol formation in aqueous particles
    • doi:10.5194/acp-10-8219-2010
    • Ervens, B. and Volkamer, R.: Glyoxal processing by aerosol multiphase chemistry: towards a kinetic modeling framework of secondary organic aerosol formation in aqueous particles, Atmos. Chem. Phys., 10, 8219-8244, doi:10.5194/acp-10-8219-2010, 2010.
    • (2010) Atmos. Chem. Phys. , vol.10 , pp. 8219-8244
    • Ervens, B.1    Volkamer, R.2
  • 15
    • 40849124168 scopus 로고    scopus 로고
    • Secondary organic aerosol yields from cloud-processing of isoprene oxidation products
    • doi:10.1029/2007GL031828
    • Ervens, B., Carlton, A. G., Turpin, B. J., Altieri, K. E., Kreidenweis, S. M., and Feingold, G.: Secondary organic aerosol yields from cloud-processing of isoprene oxidation products, Geophys. Res. Lett., 35, L02816, doi:10.1029/2007GL031828, 2008.
    • (2008) Geophys. Res. Lett. , vol.35
    • Ervens, B.1    Carlton, A.G.2    Turpin, B.J.3    Altieri, K.E.4    Kreidenweis, S.M.5    Feingold, G.6
  • 17
    • 72149099798 scopus 로고    scopus 로고
    • Cloud condensation nuclei in pristine tropical rainforest air of Amazonia: Size-resolved measurements and modeling of atmospheric aerosol composition and CCN activity
    • doi:10.5194/acp-9-7551-2009
    • Gunthe, S. S., King, S. M., Rose, D., Chen, Q., Roldin, P., Farmer, D. K., Jimenez, J. L., Artaxo, P., Andreae, M. O., Martin, S. T., and Pöschl, U.: Cloud condensation nuclei in pristine tropical rainforest air of Amazonia: size-resolved measurements and modeling of atmospheric aerosol composition and CCN activity, Atmos. Chem. Phys., 9, 7551-7575, doi:10.5194/acp-9-7551-2009, 2009.
    • (2009) Atmos. Chem. Phys. , vol.9 , pp. 7551-7575
    • Gunthe, S.S.1    King, S.M.2    Rose, D.3    Chen, Q.4    Roldin, P.5    Farmer, D.K.6    Jimenez, J.L.7    Artaxo, P.8    Andreae, M.O.9    Martin, S.T.10    Pöschl, U.11
  • 19
    • 78249270445 scopus 로고    scopus 로고
    • Oligomer content of pinene secondary organic aerosol
    • Hall,W. A. and Johnston, M. V.: Oligomer content of pinene secondary organic aerosol, Aerosol Sci. Technol, 45, 37-45, 2011.
    • (2011) Aerosol Sci. Technol , vol.45 , pp. 37-45
    • Hallw, A.1    Johnston, M.V.2
  • 20
    • 34548561750 scopus 로고    scopus 로고
    • Oligomers in the early stage of biogenic secondary organic aerosol formation and growth
    • Heaton, K. J., Dreyfus, M. A., Wang, S., and Johnston, M. V.: Oligomers in the early stage of biogenic secondary organic aerosol formation and growth, Environ. Sci. Technol., 41, 6129-6139, 2007.
    • (2007) Environ. Sci. Technol. , vol.41 , pp. 6129-6139
    • Heaton, K.J.1    Dreyfus, M.A.2    Wang, S.3    Johnston, M.V.4
  • 23
    • 84859738666 scopus 로고    scopus 로고
    • Size and time-resolved growth rate measurements of 1 to 5 nm freshly formed atmospheric nuclei
    • doi:10.5194/acp-12-3573-2012
    • Kuang, C., Chen, M., Zhao, J., Smith, J., McMurry, P. H., andWang, J.: Size and time-resolved growth rate measurements of 1 to 5 nm freshly formed atmospheric nuclei, Atmos. Chem. Phys., 12, 3573-3589, doi:10.5194/acp-12-3573- 2012, 2012.
    • (2012) Atmos. Chem. Phys. , vol.12 , pp. 3573-3589
    • Kuang, C.1    Chen, M.2    Zhao, J.3    Smith, J.4    McMurry, P.H.5    Wang, J.6
  • 25
    • 43049158155 scopus 로고    scopus 로고
    • Chemistry of secondary organic aerosol: Formation and evolution of low-volatility organics in the atmosphere
    • Kroll, J. H. and Seinfeld, J. H.: Chemistry of secondary organic aerosol: Formation and evolution of low-volatility organics in the atmosphere, Atmos. Environ., 42, 3593-3624, 2008.
    • (2008) Atmos. Environ. , vol.42 , pp. 3593-3624
    • Kroll, J.H.1    Seinfeld, J.H.2
  • 26
    • 85012473378 scopus 로고
    • Principles of gas absorption
    • Lewis, W. K. and Whitman, W. G.: Principles of gas absorption, Ind. Eng. Chem., 16, 1215-1220, 1924.
    • (1924) Ind. Eng. Chem. , vol.16 , pp. 1215-1220
    • Lewis, W.K.1    Whitman, W.G.2
  • 27
    • 84895946867 scopus 로고    scopus 로고
    • Technical Note: Analytical solution for transient partitioning and reaction of a condensing vapor species in a droplet
    • Liu, A. T., Zaveri, R. A., and Seinfeld, J. H.: Technical Note: Analytical solution for transient partitioning and reaction of a condensing vapor species in a droplet, Atmos. Environ., 89, 651-654, 2014.
    • (2014) Atmos. Environ. , vol.89 , pp. 651-654
    • Liu, A.T.1    Zaveri, R.A.2    Seinfeld, J.H.3
  • 29
    • 84873031790 scopus 로고    scopus 로고
    • Explicit modeling of volatile organic compounds partitioning in the atmospheric aqueous phase
    • doi:10.5194/acp-13-1023-2013
    • Mouchel-Vallon, C., Brauer, P., Camredon, M., Valorso, R., Madronich, S., Herrmann, H., and Aumont, B.: Explicit modeling of volatile organic compounds partitioning in the atmospheric aqueous phase, Atmos. Chem. Phys., 13, 1023-1037, doi:10.5194/acp-13-1023-2013, 2013.
    • (2013) Atmos. Chem. Phys. , vol.13 , pp. 1023-1037
    • Mouchel, V.C.1    Brauer, P.2    Camredon, M.3    Valorso, R.4    Madronich, S.5    Herrmann, H.6    Aumont, B.7
  • 30
    • 38549083271 scopus 로고    scopus 로고
    • Fulvic-like oligomers: A common process in aqueous and ionic atmospheric particles?
    • Formation of secondary light-absorbing doi:10.1029/2007GL031300
    • Nozière, B., Dziedzic, P., and Córdova, A.: Formation of secondary light-absorbing "fulvic-like" oligomers: A common process in aqueous and ionic atmospheric particles?, Geophys. Res. Lett., 34, L21812, doi:10.1029/2007GL031300, 2007.
    • (2007) Geophys. Res. Lett. , vol.34
    • Nozière, B.1    Dziedzic, P.2    Córdova, A.3
  • 32
    • 0028183902 scopus 로고
    • An absorption model of gas/particle partitioning of organic compounds in the atmosphere
    • Pankow, J. F.: An absorption model of gas/particle partitioning of organic compounds in the atmosphere, Atmos. Environ., 28, 185-188, 1994.
    • (1994) Atmos. Environ. , vol.28 , pp. 185-188
    • Pankow, J.F.1
  • 33
    • 79551486463 scopus 로고    scopus 로고
    • Modeling secondary organic aerosol using a dynamic partitioning approach incorporating particle aqueous-phase chemistry
    • Parikh, H. M., Carlton, A. G., Vizuete, W., and Kamens, R. M.: Modeling secondary organic aerosol using a dynamic partitioning approach incorporating particle aqueous-phase chemistry, Atmos. Environ., 45, 1126-1137, 2011.
    • (2011) Atmos. Environ. , vol.45 , pp. 1126-1137
    • Parikh, H.M.1    Carlton, A.G.2    Vizuete, W.3    Kamens, R.M.4
  • 35
    • 80052490480 scopus 로고    scopus 로고
    • Quantification of the volatility of secondary organic compounds in ultrafine particles during nucleation events
    • doi:10.5194/acp-11-9019-2011
    • Pierce, J. R., Riipinen, I., Kulmala, M., Ehn, M., Petäjä, T., Junninen, H., Worsnop, D. R., and Donahue, N. M.: Quantification of the volatility of secondary organic compounds in ultrafine particles during nucleation events, Atmos. Chem. Phys., 11, 9019-9036, doi:10.5194/acp-11-9019- 2011, 2011.
    • (2011) Atmos. Chem. Phys. , vol.11 , pp. 9019-9036
    • Pierce, J.R.1    Riipinen, I.2    Kulmala, M.3    Ehn, M.4    Petäjä, T.5    Junninen, H.6    Worsnop, D.R.7    Donahue, N.M.8
  • 37
    • 36949008066 scopus 로고    scopus 로고
    • Kinetic model framework for aerosol and cloud surface chemistry and gas-particle interactions-Part 1: General equations, parameters, and terminology
    • doi:10.5194/acp-7-5989-2007
    • Pöschl, U., Rudich, Y., and Ammann, M.: Kinetic model framework for aerosol and cloud surface chemistry and gas-particle interactions-Part 1: General equations, parameters, and terminology, Atmos. Chem. Phys., 7, 5989-6023, doi:10.5194/acp-7-5989-2007, 2007.
    • (2007) Atmos. Chem. Phys. , vol.7 , pp. 5989-6023
    • Pöschl, U.1    Rudich, Y.2    Ammann, M.3
  • 42
    • 0003996643 scopus 로고    scopus 로고
    • Atmospheric Chemistry and Physics: From Air Pollution to Climate Change
    • 2nd Edn.. John Wiley & Hoboken, NJ
    • Seinfeld, J. H. and Pandis, S. N.: Atmospheric Chemistry and Physics: From Air Pollution to Climate Change (2nd Edn.). John Wiley & Sons, Inc., Hoboken, NJ, 2006.
    • (2006) Sons, Inc.
    • Seinfeld, J.H.1    Pandis, S.N.2
  • 43
    • 0019711102 scopus 로고
    • Mass-transport limitation to the rate of reaction of gases in liquid droplets: Application to oxidation of SO2 in aqueous solutions
    • Schwartz, S. E. and Freiberg, J. E.: Mass-transport limitation to the rate of reaction of gases in liquid droplets: application to oxidation of SO2 in aqueous solutions. Atmos. Environ., 15, 1129-1144, 1981.
    • (1981) Atmos. Environ. , vol.15 , pp. 1129-1144
    • Schwartz, S.E.1    Freiberg, J.E.2
  • 44
    • 84901389155 scopus 로고
    • On mass-transport limitation to the rate of reaction of gases in liquid droplets
    • Shi, B. and Seinfeld, J.H: On mass-transport limitation to the rate of reaction of gases in liquid droplets. Atmos. Environ., 22, 2491-2499, 1991.
    • (1991) Atmos. Environ. , vol.22 , pp. 2491-2499
    • Shi, B.1    Seinfeld, J.H.2
  • 46
    • 84871258925 scopus 로고    scopus 로고
    • Equilibration timescale of atmospheric secondary organic aerosol partitioning
    • doi:10.1029/2012GL054008, 2012b
    • Shiraiwa, M. and Seinfeld, J. H.: Equilibration timescale of atmospheric secondary organic aerosol partitioning, Geophys. Res. Lett., 39, L24801, doi:10.1029/2012GL054008, 2012b.
    • Geophys. Res. Lett. , vol.39
    • Shiraiwa, M.1    Seinfeld, J.H.2
  • 47
    • 84858673026 scopus 로고    scopus 로고
    • Kinetic multilayer model of gas-particle interactions in aerosols and clouds (KM-GAP)
    • linking condensation, evaporation, and chemical reactions of organics, oxidants and water doi:10.5194/acp-12-2777-2012, 2012a
    • Shiraiwa, M., Pfrang, C., Koop, T., and Pöschl, U.: Kinetic multilayer model of gas-particle interactions in aerosols and clouds (KM-GAP): linking condensation, evaporation, and chemical reactions of organics, oxidants and water. Atmos. Chem. Phys., 12, 2777-2794, doi:10.5194/acp-12-2777-2012, 2012a.
    • Atmos. Chem. Phys. , vol.12 , pp. 2777-2794
    • Shiraiwa, M.1    Pfrang, C.2    Koop, T.3    Pöschl, U.4
  • 49
    • 84881115702 scopus 로고    scopus 로고
    • Gasparticle partitioning of atmospheric aerosols: Interplay of physical state, non-ideal mixing and morphology
    • Shiraiwa, M., Zuend, A., Bertram, A. K., and Seinfeld, J. H.: Gasparticle partitioning of atmospheric aerosols: interplay of physical state, non-ideal mixing and morphology, Phys. Chem. Chem. Phys., 15, 11441-11453, 2013b.
    • (2013) Phys. Chem. Chem. Phys. , vol.15 , pp. 11441-11453
    • Shiraiwa, M.1    Zuend, A.2    Bertram, A.K.3    Seinfeld, J.H.4
  • 50
    • 33645942097 scopus 로고    scopus 로고
    • Condensation and activation in sectional cloud microphysical models
    • Simmel, M. and Wurzler, S.: Condensation and activation in sectional cloud microphysical models, Atmos. Res., 80, 218-236, 2006.
    • (2006) Atmos. Res. , vol.80 , pp. 218-236
    • Simmel, M.1    Wurzler, S.2
  • 51
    • 43449119484 scopus 로고    scopus 로고
    • Chemical composition of atmospheric nanoparticles formed from nucleation in Tecamac, Mexico: Evidence for an important role for organic species in nanoparticle growth
    • doi:10.1029/2007GL032523
    • Smith, J. N., Dunn, M. J., VanReken, T. M., Iida, K., Stolzenburg, M. R., McMurry, P. H., and Huey, L. G.: Chemical composition of atmospheric nanoparticles formed from nucleation in Tecamac, Mexico: Evidence for an important role for organic species in nanoparticle growth, Geophys. Res. Lett., 35, L04808, doi:10.1029/2007GL032523, 2008.
    • (2008) Geophys. Res. Lett. , vol.35
    • Smith, J.N.1    Dunn, M.J.2    Vanreken, T.M.3    Iida, K.4    Stolzenburg, M.R.5    McMurry, P.H.6    Huey, L.G.7
  • 54
    • 79952129020 scopus 로고    scopus 로고
    • Evaporation kinetics and phase of laboratory and ambient secondary organic aerosol
    • Vaden, T. D., Imre, D., Beránek, J., Shrivastava, M., and Zelenyuk, A.: Evaporation kinetics and phase of laboratory and ambient secondary organic aerosol, Proc. Nat. Acad. Sci. USA, 108, 2190-2195, 2011.
    • (2011) Proc. Nat. Acad. Sci. USA , vol.108 , pp. 2190-2195
    • Vaden, T.D.1    Imre, D.2    Beránek, J.3    Shrivastava, M.4    Zelenyuk, A.5
  • 56
    • 77950436195 scopus 로고    scopus 로고
    • Atmospheric nanoparticles formed from heterogeneous reactions of organics
    • Wang, L., Khalizov, A. F., Zheng, J., Xu, W., Ma, Y., Lal, V., and Zhang, R.: Atmospheric nanoparticles formed from heterogeneous reactions of organics, Nature Geoscience, 3, 238-242, 2010.
    • (2010) Nature Geoscience , vol.3 , pp. 238-242
    • Wang, L.1    Khalizov, A.F.2    Zheng, J.3    Xu, W.4    Ma, Y.5    Lal, V.6    Zhang, R.7
  • 60
    • 0013486568 scopus 로고    scopus 로고
    • Development and evaluation of a comprehensive tropospheric chemistry model for regional and global applications
    • Ph.D. thesis, Virginia Polytech Blacksburg, Virginia
    • Zaveri, R. A.: Development and evaluation of a comprehensive tropospheric chemistry model for regional and global applications, Ph.D. thesis, Virginia Polytech. Inst. and State Univ., Blacksburg, Virginia, 1997.
    • (1997) Inst. and State Univ.
    • Zaveri, R.A.1
  • 61
    • 49049087110 scopus 로고    scopus 로고
    • Model for Simulating Aerosol Interactions and Chemistry (MOSAIC)
    • doi:10.1029/2007JD008782
    • Zaveri, R. A., Easter, R. C., Fast, J. D., and Peters, L. K.: Model for Simulating Aerosol Interactions and Chemistry (MOSAIC), J. Geophys. Res., 113, D13204, doi:10.1029/2007JD008782, 2008.
    • (2008) J. Geophys. Res. , vol.113
    • Zaveri, R.A.1    Easter, R.C.2    Fast, J.D.3    Peters, L.K.4
  • 64
    • 84862286621 scopus 로고    scopus 로고
    • Diffusion-limited versus quasi-equilibrium aerosol growth
    • doi:10.1080/02786826.2012.679344
    • Zhang, X., Pandis, S. N., and Seinfeld, J. H.: Diffusion-limited versus quasi-equilibrium aerosol growth, Aerosol Science and Technology, 46, 874-885, doi:10.1080/02786826.2012.679344, 2012.
    • (2012) Aerosol Science and Technology , vol.46 , pp. 874-885
    • Zhang, X.1    Pandis, S.N.2    Seinfeld, J.H.3
  • 65
    • 84871828554 scopus 로고    scopus 로고
    • Kinetics, products, and mechanisms of secondary organic aerosol formation
    • Ziemann, P. J. and Atkinson, R.: Kinetics, products, and mechanisms of secondary organic aerosol formation, Chem. Soc. Rev., 41, 6582-6605, 2012.
    • (2012) Chem. Soc. Rev. , vol.41 , pp. 6582-6605
    • Ziemann, P.J.1    Atkinson, R.2


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