scholarly journals A model of aerosol evaporation kinetics in a thermodenuder

2010 ◽  
Vol 3 (3) ◽  
pp. 579-592 ◽  
Author(s):  
C. D. Cappa
Keyword(s):  
Gas Phase ◽  
Quantitative Agreement ◽  
Evaporation And Condensation ◽  
Heating Section ◽  
Calculated Mass ◽  
Quantitative Understanding ◽  
Pass Through ◽  
Kinetics Of ◽  
Measured Mass ◽  
Evaporation Kinetics

Abstract. Aerosol thermodenuders provide a measure of particle volatility. The information provided by a thermodenuder is fundamentally related to the kinetics of evaporation and condensation within the device. Here, a time-dependent, multi-component model of particle and gas-phase mass transfer in a thermodenuder is described. This model empirically accounts for the temperature profile along the length of a typical thermodenuder and distinguishes between the influence of the heating section and of the adsorbent denuder section. It is shown that "semi-volatile" aerosol is particularly sensitive to the inclusion of an adsorbent denuder in the model. As expected, the mass loss from evaporation of particles as they pass through the thermodenuder is directly related to the compound vapor pressure, although the assumptions regarding the enthalpy of vaporization are shown to also have a large influence on the overall calculated mass thermograms. The model has been validated by comparison with previously measured mass thermograms for single-component aerosols and is shown to provide reasonable semi-quantitative agreement. The model that has been developed here can be used to provide quantitative understanding of aerosol volatility measurements of single and multi-component aerosol made using thermodenuders that include adsorbent denuder sections.

scholarly journals A model of aerosol evaporation kinetics in a thermodenuder

2009 ◽  
Vol 2 (5) ◽  
pp. 2749-2779 ◽  
Author(s):  
C. D. Cappa
Keyword(s):  
Gas Phase ◽  
Quantitative Agreement ◽  
Enthalpy Of Vaporization ◽  
Evaporation And Condensation ◽  
Heating Section ◽  
Calculated Mass ◽  
Quantitative Understanding ◽  
Kinetics Of ◽  
Measured Mass ◽  
Evaporation Kinetics

Abstract. Aerosol thermodenuders provide a measure of particle volatility. The information provided by a thermodenuder is fundamentally related to the kinetics of evaporation and condensation within the device. Here, a time-dependent, multi-component model of particle and gas-phase mass transfer in a thermodenuder is described. This model explicitly accounts for the temperature profile along the length of a typical thermodenuder and distinguishes between the influence of the heating section and of the adsorbent denuder section. It is shown that "semi-volatile" aerosol is particularly sensitive to the inclusion of the adsorbent denuder in the model. As expected, the mass loss from particles through the thermodenuder is directly related to the compound vapor pressure, although the assumptions regarding the enthalpy of vaporization are shown to also have a large influence on the overall calculated mass thermograms. The model has been validated by comparison with previously measured mass thermograms for single-component aerosols and is shown to provide reasonable semi-quantitative agreement. The model that has been developed here can be used to provide quantitative understanding of aerosol volatility measurements of single and multi-component aerosol made using thermodenuders.

scholarly journals Dissecting the self-assembly kinetics of multimeric pore-forming toxins

2016 ◽  
Vol 13 (114) ◽  
pp. 20150762 ◽  
Author(s):  
A. A. Lee ◽  
M. J. Senior ◽  
M. I. Wallace ◽  
T. E. Woolley ◽  
I. M. Griffiths
Keyword(s):  
Single Molecule ◽  
Self Assembly ◽  
Quantitative Agreement ◽  
Time Resolved ◽  
Biologically Relevant ◽  
Low Concentrations ◽  
Assembly Kinetics ◽  
Quantitative Understanding ◽  
Mechanism And Kinetics ◽  
Kinetics Of

Pore-forming toxins are ubiquitous cytotoxins that are exploited by both bacteria and the immune response of eukaryotes. These toxins kill cells by assembling large multimeric pores on the cell membrane. However, a quantitative understanding of the mechanism and kinetics of this self-assembly process is lacking. We propose an analytically solvable kinetic model for stepwise, reversible oligomerization. In biologically relevant limits, we obtain simple algebraic expressions for the rate of pore formation, as well as for the concentration of pores as a function of time. Quantitative agreement is obtained between our model and time-resolved kinetic experiments of Bacillus thuringiensis Cry1Ac (tetrameric pore), aerolysin, Staphylococcus aureus α -haemolysin (heptameric pores) and Escherichia coli cytolysin A (dodecameric pore). Furthermore, our model explains how rapid self-assembly can take place with low concentrations of oligomeric intermediates, as observed in recent single-molecule fluorescence experiments of α-haemolysin self-assembly. We propose that suppressing the concentration of oligomeric intermediates may be the key to reliable, error-free, self-assembly of pores.

Evaporation kinetics of a polydisperse ensemble of drops

2021 ◽  
Vol 379 (2205) ◽  
pp. 20200309 ◽  
Author(s):  
Alexander A. Ivanov ◽  
Irina V. Alexandrova ◽  
Dmitri V. Alexandrov
Keyword(s):  
Gas Phase ◽  
Condensed Matter ◽  
Planck Equation ◽  
Decisive Role ◽  
Cooling Power ◽  
Theme Issue ◽  
Diffusion Term ◽  
Liquid Drops ◽  
Kinetics Of ◽  
Evaporation Kinetics

A mathematical model of the evaporation of a polydisperse ensemble of drops, with allowance for a nonlinear ‘diffusion’ term in the kinetic equation for the population density distribution function, is developed. The model describes the interaction of a gas phase with vaporizing drops: it has great potential for application in condensed matter physics, thermophysics and engineering devices (e.g. spray drying, cooling, power engineering). The kinetics of heat transfer between phases is theoretically studied. An analytical solution to the integro-differential equations of the process of droplet evaporation is found in a parametric form. Analytical solutions in the presence and absence of the ‘diffusion’ term are compared. It is shown that the fluctuations in particle evaporation rates (‘diffusion’ term in the Fokker–Planck equation) play a decisive role in the evolutionary behaviour of a polydisperse ensemble of vaporizing liquid drops. This article is part of the theme issue ‘Transport phenomena in complex systems (part 1)’.

scholarly journals The evaporation kinetics of pure water droplets at varying drying rates and the use of evaporation rates to infer the gas phase relative humidity

2018 ◽  
Vol 20 (36) ◽  
pp. 23453-23466 ◽  
Author(s):  
Yong-yang Su ◽  
Rachael E. H. Miles ◽  
Zhi-ming Li ◽  
Jonathan P. Reid ◽  
Jiang Xu
Keyword(s):  
Relative Humidity ◽  
Gas Phase ◽  
Aerosol Particles ◽  
Pure Water ◽  
Analytical Models ◽  
Volatile Components ◽  
Water Droplets ◽  
Drying Rates ◽  
Kinetics Of ◽  
Evaporation Kinetics

Numerous analytical models have been applied to describe the evaporation/condensation kinetics of volatile components from aerosol particles for use in many applications.

Diffusion model for deposition of epitaxial GaAs layers prepared by the MOCVD method

1991 ◽  
Vol 56 (10) ◽  
pp. 2020-2029
Author(s):  
Jindřich Leitner ◽  
Petr Voňka ◽  
Josef Stejskal ◽  
Přemysl Klíma ◽  
Rudolf Hladina
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Kinetic Model ◽  
Gas Phase ◽  
Substrate Surface ◽  
Deposition Process ◽  
Hydrogen Atmosphere ◽  
Epitaxial Gaas ◽  
Kinetics Of ◽  
Good Agreement

The authors proposed and treated quantitatively a kinetic model for deposition of epitaxial GaAs layers prepared by reaction of trimethylgallium with arsine in hydrogen atmosphere. The transport of gallium to the surface of the substrate is considered as the controlling process. The influence of the rate of chemical reactions in the gas phase and on the substrate surface on the kinetics of the deposition process is neglected. The calculated dependence of the growth rate of the layers on the conditions of the deposition is in a good agreement with experimental data in the temperature range from 600 to 800°C.

Gas-Phase Anionic Metal Clusters are Model Systems for Surface Oxidation: Kinetics of the Reactions of Mn– with O2 (M = V, Cr, Co, Ni; n = 1–15)

2021 ◽  
Vol 125 (10) ◽  
pp. 2069-2076
Author(s):  
Brendan C. Sweeny ◽  
David C. McDonald ◽  
Nicholas S. Shuman ◽  
Albert A. Viggiano ◽  
Juergen Troe ◽  
...  
Keyword(s):  
Gas Phase ◽  
Oxidation Kinetics ◽  
Metal Clusters ◽  
Surface Oxidation ◽  
Model Systems ◽  
Kinetics Of

Theoretical study of the mechanisms for the homogenous gas-phase elimination kinetics of some 2-hydroxynitroalkanes

2006 ◽  
Vol 19 (12) ◽  
pp. 836-840 ◽  
Author(s):  
Rafael Añez ◽  
Rodolfo Izquierdo ◽  
Alba Vidal ◽  
Tania Cordova ◽  
Aníbal Sierraalta ◽  
...  
Keyword(s):  
Gas Phase ◽  
Theoretical Study ◽  
Elimination Kinetics ◽  
Kinetics Of ◽  
Phase Elimination
Sign in / Sign up

Export Citation Format

Share Document