scholarly journals Lateral gas phase diffusion length of boron atoms over Si/B surfaces during CVD of pure boron layers

AIP Advances ◽  
2016 ◽  
Vol 6 (2) ◽  
pp. 025103
Author(s):  
V. Mohammadi ◽  
S. Nihtianov
Keyword(s):  
Gas Phase ◽  
Diffusion Length ◽  
Phase Diffusion

scholarly journals Theoretical analysis of ultra-lean premixed flames in porous inert media

2010 ◽  
Vol 657 ◽  
pp. 285-307 ◽  
Author(s):  
F. M. PEREIRA ◽  
A. A. M. OLIVEIRA ◽  
F. F. FACHINI
Keyword(s):  
Heat Transfer ◽  
Energy Conservation ◽  
Gas Phase ◽  
Diffusion Length ◽  
Length Scale ◽  
Interphase Heat Transfer ◽  
Phase Diffusion ◽  
Phase Temperature ◽  
Porous Inert Media ◽  
Inner Region

The structure of stationary adiabatic premixed flames within porous inert media under intense interphase heat transfer is investigated using the asymptotic expansion method. For the pore sizes of interest for combustion in porous inert media, this condition is reached for extremely lean mixtures where lower flame velocities are found. The flame structure is analysed in three distinct regions. In the outer region (the solid-phase diffusion length scale), both phases are in local thermal equilibrium and the problem formulation is reduced to the one-equation model for the energy conservation. In the first inner region (the gas-phase diffusion length scale), there is local thermal non-equilibrium and two equations for the energy conservation are required. In this region, the gas-phase temperature at the flame is limited by the interphase heat transfer. In the second inner region (the reaction length scale), the chemical reaction occurs in a very thin zone where the highest gas-phase temperature is found. The results showed that superadiabatic effects are reduced for leaner mixtures, smaller pore sizes and smaller fuel Lewis numbers. The results also show that there is a minimum superadiabatic temperature for the flame propagation to be possible, which corresponds to the lean flammability limit for the premixed combustion in porous inert media. A parameter that universalizes the leading-order flame properties is identified and discussed.

scholarly journals Combined surface and gas phase diffusion through plugs of porous adsorbent in transition diffusion region.

1981 ◽  
Vol 14 (1) ◽  
pp. 13-19 ◽  
Author(s):  
MASASHI ASAEDA ◽  
JIRO WATANABE ◽  
YASUSHI MATONO ◽  
KOJI KOJIMA ◽  
RYOZO TOEI
Keyword(s):  
Gas Phase ◽  
Diffusion Region ◽  
Phase Diffusion ◽  
Porous Adsorbent

What is effective ΔPO2 in a gas-phase diffusion system?

1981 ◽  
Vol 45 (1) ◽  
pp. 9-11 ◽  
Author(s):  
C.V. Paganelli ◽  
A. Ar ◽  
H. Rahn
Keyword(s):  
Gas Phase ◽  
Diffusion System ◽  
Phase Diffusion

Numerical analysis of gas-phase diffusion resistance in a droplet train apparatus

2002 ◽  
Vol 362 (1-2) ◽  
pp. 56-62 ◽  
Author(s):  
Masakazu Sugiyama ◽  
Seiichiro Koda ◽  
Akihiro Morita
Keyword(s):  
Numerical Analysis ◽  
Gas Phase ◽  
Diffusion Resistance ◽  
Phase Diffusion

NEW METHOD FOR PREDICTION OF BINARY GAS-PHASE DIFFUSION COEFFICIENTS

1966 ◽  
Vol 58 (5) ◽  
pp. 18-27 ◽  
Author(s):  
Edward N. Fuller ◽  
Paul D. Schettler ◽  
J. Calvin. Giddings
Keyword(s):  
Gas Phase ◽  
Diffusion Coefficients ◽  
New Method ◽  
Phase Diffusion

scholarly journals Technical note: Determination of binary gas-phase diffusion coefficients of unstable and adsorbing atmospheric trace gases at low temperature – arrested flow and twin tube method

2020 ◽  
Vol 20 (6) ◽  
pp. 3669-3682 ◽  
Author(s):  
Stefan Langenberg ◽  
Torsten Carstens ◽  
Dirk Hupperich ◽  
Silke Schweighoefer ◽  
Ulrich Schurath
Keyword(s):  
Gas Phase ◽  
Diffusion Coefficients ◽  
Trace Gases ◽  
Heterogeneous Reactions ◽  
Viscosity Data ◽  
Atmospheric Conditions ◽  
Binary Diffusion ◽  
Phase Diffusion ◽  
Flow Method ◽  
Binary Diffusion Coefficients

Abstract. Gas-phase diffusion is the first step for all heterogeneous reactions under atmospheric conditions. Knowledge of binary diffusion coefficients is important for the interpretation of laboratory studies regarding heterogeneous trace gas uptake and reactions. Only for stable, nonreactive and nonpolar gases do well-established models for the estimation of diffusion coefficients from viscosity data exist. Therefore, we have used two complementary methods for the measurement of binary diffusion coefficients in the temperature range of 200 to 300 K: the arrested flow method is best suited for unstable gases, and the twin tube method is best suited for stable but adsorbing trace gases. Both methods were validated by the measurement of the diffusion coefficients of methane and ethane in helium and air as well as nitric oxide in helium. Using the arrested flow method the diffusion coefficients of ozone in air, dinitrogen pentoxide and chlorine nitrate in helium, and nitrogen were measured. The twin tube method was used for the measurement of the diffusion coefficient of nitrogen dioxide and dinitrogen tetroxide in helium and nitrogen.

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