Laser heating of an aqueous aerosol particle

Sageev, Gideon; Seinfeld, John H.

doi:10.1364/ao.23.004368

Cited by 31 publications

(8 citation statements)

References 11 publications

(15 reference statements)

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“…The relative partial molal enthalpy and heat capacity are calculated for NaCl solution using the formulas (Sageev & Seinfeld, 1984;Gibbard et al, 1974) The uptake of water and growth of the particle can change the density of particles. Consequently, the particle deposition efficiency through impaction and sedimentation also may change.…”

Section: For a Solution Droplet X D (T D ) ≈ A W (T D )X 0 (T D )mentioning

confidence: 99%

Particle deposition in human respiratory system: Deposition of concentrated hygroscopic aerosols

Varghese

Gangamma

2009

Inhalation Toxicology

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In the nearly saturated human respiratory tract, the presence of water-soluble substances in the inhaled aerosols can cause change in the size distribution of the particles. This consequently alters the lung deposition profiles of the inhaled airborne particles. Similarly, the presence of high concentration of hygroscopic aerosols also affects the water vapor and temperature profiles in the respiratory tract. A model is presented to analyze these effects in human respiratory system. The model solves simultaneously the heat and mass transfer equations to determine the size evolution of respirable particles and gas-phase properties within human respiratory tract. First, the model predictions for nonhygroscopic aerosols are compared with experimental results. The model results are compared with experimental results of sodium chloride particles. The model reproduces the major features of the experimental data. The water vapor profile is significantly modified only when a high concentration of particles is present. The model is used to study the effect of equilibrium assumptions on particle deposition. Simulations show that an infinite dilution solution assumption to calculate the saturation equilibrium over droplet could induce errors in estimating particle growth. This error is significant in the case of particles of size greater than 1 mum and at number concentrations higher than 10(5)/cm(3).

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Section: For a Solution Droplet X D (T D ) ≈ A W (T D )X 0 (T D )mentioning

confidence: 99%

Particle deposition in human respiratory system: Deposition of concentrated hygroscopic aerosols

Varghese

Gangamma

2009

Inhalation Toxicology

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“…Many researchers have conducted condensation/evapomtion experiments in electrodynamic chambers (e.g., Davis et al, 1978;Zhang and Davis, 1987;Sageev and Seinfeld, 1984). Others have studied charged particle fission as highly charged, evaporating droplets approach the Rayleigh charge limit (e. g., Taflin et al, 1989;Doyle et al, 1964).…”

Section: Effect Of Charge On Balance Resultsmentioning

confidence: 99%

Vapor scavenging by atmospheric aerosol particles

Andrews¹

1996

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Particle growth due to vapor scavenging was studied using both experimental and computational techniques. Vapor scavenging by particles is an important physical process in the atmosphere because it can result in changes to particle properties (e.g., size, shape, composition, and activity) and, thus, influence atmospheric phenomena in which particles play a role, such as cloud formation and long range transport. In the modelling portion of this thesis, the influence of organic vapor on the evolution of a particle mass size distribution was investigated using a modified version of MAEROS (a multicomponent aerosol dynamics code) (Gelbard and Seinfeld, 1984). The modelling study attempted to identify the sources of organic aerosol observed by Novakov and Penner (1993) in a field study in Puerto Rim. Potential sources were hypothesized to be organic vapor emissions from either forest vegetation near the sampling site OT from the ocean's surfactant layer followed by gas-to-particle conversion. Comparison of model parameters with literature values suggested that the observed organic aerosol was fomed by nucleation and condensation of terpene vapor emissions onto a pre-existing typical marine aerosol size distribution. Organic vapor emissions from the ocean were found to be an unlikely source of the observed organic aerosol. Experimentally, vapor scavenging and particle growth were investigated using two techniques. The influence of the presence of organic in a particle on the particle's hydroscopicity was investigated using an electrodynamic balance. It was found that, far a Tween8O/NaCl system, having organic associated with an inorganic salt particle slowed the deliquescence rate of the particle. Additionally, for the Tween80/NaC1 system the deliquescence humidity was lowered due to the presence of organicsuggesting an increase in particle hydroscopicity. It was also shown bat the presence of an organic carbon (e.g., azelaic acid, Tween80 or dodecyl sulfate sodium salt) on a carbon black particle made the carbon black particle Rygrophilic, while a pure carbon black particle was observed to be hydrophobic. The charge on a particle (which is required for study of a particle in the eleclmdynamic balance) was investigated theoretically and experimentally. Particle charge was found to have a negligible effect on particle growth in electrodynamic balance studies. A prototype apparatusthe refhctive index thermal diffusion chamber (RITDC)was developed to study multiple particles in the same environment at the same time. Proof of concept experiments showed that it is possible to determine particle composition with rime from changes in particle refractive index measured using the RITDC. Further refinements to the apparatus were suggested.

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“…Assuming steady state conditions, flux and gradient terms in the Eq. (1) are given by (Williams, 1965;Sageev and Seinfeld, 1984) ( )…”

Section: Methodsmentioning

confidence: 99%