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Table 1 Summary of symbols used in equations

From: Experimental and theoretical simulation of sublimating dusty water ice with implications for D/H ratios of water ice on Comets and Mars

Symbol Units Definition
A molec s kg-1 Constant from Equation (1.a)
A surf m2 Surface area of the frozen sample
A S m2 kg-1 Specific surface area of the regolith available for adsorption
α Pa-1 Langmuir adsorption constant (subscripts refer to the species)
B m3 molec-1 Constant from Equation (1.b)
C kg m molec-1 s-1 Constant from Equation (1.c)
χ dimensionless Mass fraction (subscripts: Z = of dust; H2O = of water)
D eff m2s-1 Diffusivity (subscripts: eff = Effective Diffusivity; 0 = time independent) When bolded represents a 2- element vector with [H2O HDO]
e sys dimensionless Pumping efficiency (pressure ratio between chamber and QMS-inlet)
G dimensionless Rate coefficient matrix
γ Z dimensionless Volume fraction of dust in lag mantle
k dimensionless Rate constant, Superscripts: ads = adsorption, des = desorption, X = cross-reaction substitution by vapor-phase species. When bolded represents a 2- element vector with [H2O HDO]
k B m2 kg s-2 K-1 Boltzmann Constant (1.38 × 10-23)
J molec m-2 s-1 Molecular flux at a point in the apparatus
k s-1 Langmuir adsorption kinetic constant, Subscripts: H2O, HDO, X = substitution; Superscripts: ads = adsorption, des = desorption
l m Thickness of an adsorbed monolayer of water (2.75 × 10-10)
m H2O kg molec-1 Mass of a single water molecule (2.99 × 10-26)
M H2O kg mol-1 Molar Mass (0.01802 for water)
N A molec mol-1 Avogadro's Number (6.02 × 1023)
n molec m-3 Number density of molecules
p Pa Pressure (subscripts: sat = Saturated Vapor Pressure)
R m2K-1s-2 Specific Gas Constant (462 for water)
R u J mol-1 K-1 Universal Gas Constant (8.3145)
ρ kg m-3 Density (subscripts: Z = of dust; reg = of regolith; H2O = of water)
Ψ J m-3 Thermodynamic Adsorption Constant
T K Temperature (subscripts: QMS = the tubing at the throat of the QMS)
t s Time (subscripts: 0 = initial time)
θ dimensionless Fraction of adsorption sites occupied by water molecules when bolded indicates a two-element vector with [H2O HDO]
V m3 s-1 Pumping speed
z m Thickness of dust lag (subscripts: 0 = initial time)