Symboles

Description

Valeurs

Unités

Sources

λ

Wave length of radiation blue and red

430 - 460

645 - 665

nm

nm

Standard

h

Planck number

6.626 × 10−34

m2∙kg∙S−1

C

light speed

3 × 108

m∙S−1

N

Avogadro number

6.02 × 1023

mol−1

R

Constant of the perfect gas

8.31

J∙mol−1∙K−1

V e a u

Molar volume of water

18 × 10−3

l∙mol−1

ρ

Density of water in the xylem

103

kg∙m−3

g

Acceleration of gravity

9.81

m∙S−2

r

Radius of the root

5 × 10−4

m

[8]

k x

Axial conductivity of the root

10−9

m4∙Pa−1∙S−1

k r

Radial conductivity of the root

2.5 × 10−7

m∙Pa−1∙S−1