Water and Solute Permeability of Plant Cuticles: Measurement and ...

Appendix A 277
Symbols (continued)
Symbol Quantity Magnitude
∆H Enthalpy change kJmol −1
η viscosity Pa s
J Mass flux kgm −2 s −1
Jv Volume flux of gas or vapour m 3 (STP)m −2 s −1
Js Solute flux molm −2 s −1
Jw Mass flux of water kgm −2 s −1
Jwv Mass flux of water vapour kgm −2 s −1
K Partition coefficient –
KHg Water partition coefficient calculated as
PHg/D
–
Kw Water partition coefficient cm 3 liquid water cm −3 polymer
Kwrec
Solute partition coefficient between CM, MX,
or wax and aqueous solutions
Kwv Water vapour partition coefficient cm 3 vapour cm −3 polymer
Kow Octanol/water partition coefficient –
Kcw CM/water partition coefficient –
Kmxw MX/water partition coefficient –
Kcuw Cutin/water partition coefficient –
Kww Wax/water partition coefficient –
k Mass transfer coefficient s−1 k ∗
UDOS mass transfer coefficient s−1 k ∗
o UDOS mass transfer coefficient of a solute
having zero molar volume
s−1 k ∗
infinite Pre-exponential factor of the Arrhenius
equation ln k ∗ vs.1/T
s−1 k Slope of the Freundlich isotherm
k ′ Slope of the modified Freundlich isotherm
ℓ Membrane thickness m
λ Mean free path of solute in polymers m
m Mass kg
M Amount mol
µ Chemical potential of solvent or solute –
N Mole fraction –
P Permeability of a membrane of 1 m thickness m 2 s −1
Pw
Water permeability of a membrane having
1 m thickness calculated using aw as
driving force
–
m 2 s −1
Pwv Water vapour permeability of a membrane
having 1 m thickness calculated using Cwv
as driving force
P Permeance of a membrane ms−1 PHg Permeance calculated using a vapour pressure
of 1 cm Hg as driving force. Usually for a
membrane having ℓ = 1cm
Water permeance calculated using aw as ms−1 Pw
Pwv
driving force
Water vapour permeance calculated using
water vapour concentration (Cwv) as
driving force
m 2 s −1
cm 3 vapour (STP) cm −2 s −1
ms −1
(continued)