Biomedical Engineering Reference
In-Depth Information
Figure 5.9
Wall concentration of immobilized nanoparticles (particles/
m
m
2
) as a function of
time—a comparison between measurements (dots), Ilkovic's solution, and numerical results. Before
2
( 2)
e
, all the results are close together. After the time
t
, the Ilkovic solution
departs from the experimental results whereas the numerical results still agree with the experimental
results.
t
2166
s
< =
=
4
D
5.3.6 Radial Diffusion
In the case of a purely radial diffusion from a source point or a central sphere (Fig-
ure 5.11), the diffusion equation is
é
2
ù
¶
c
¶
c
2
¶
c
=
D
+
(5.27)
ê
ú
2
¶
t
r
¶
r
¶
r
ë
û
Figure 5.10
Vertical profiles of concentration
c
/
c
0
versus time.
