Biomedical Engineering Reference
In-Depth Information
160
200
140
120
100
80
150
100
60
40
20
50
0
0
0
5
10
15
20
25
0
5
10
15
20
A
B
Time (s)
Time (s)
120
100
80
60
40
20
0
0
5
10
15
20
25
C
Time (s)
Figure 10.12
Influence of the carrier gas on the binding of NH
3
to an optical fiber-based evanescent sensor
(
Cao and Duan, 2005
): (a) Air (b) N
2
(c) Ar. When only a solid line (--) is used then a single-fractal
analysis applies. When both a dashed (- - -) and a solid (--) line are used then the dashed line
represents a single-fractal analysis and the solid line represents a dual-fractal analysis.
Figure 10.12b
shows the binding of 145 ppm NH
3
in nitrogen (carrier gas) to the optical
fiber-based evanescent ammonia sensor (
Cao and Duan, 2005
). A dual-fractal analysis is
required to adequately describe the binding kinetics. The values of (a) the binding rate co-
efficient,
k
, and the fractal dimension,
D
f
, for a single-fractal analysis, and (b) the binding rate
coefficients,
k
1
and
k
2
, and the fractal dimensions,
D
f1
and
D
f2
, for a dual-fractal analysis are
given in
Table 10.9
. It is of interest to note that as the fractal dimension increases by a factor
of 2.51 from a value of
D
f1
equal to 0.9568 to
D
f2
equal to 2.40, the binding rate coefficient
increases by a factor of 2.40 from a value of
k
1
equal to 24.885 to
k
2
equal to 59.642.
Figure 10.12c
shows the binding of 145 ppm NH
3
in Ar (carrier gas) to the optical fiber-
based evanescent ammonia sensor (
Cao and Duan, 2005
). A dual-fractal analysis is required
to adequately describe the binding kinetics. The values of (a) the binding rate coefficient,
k
,
and the fractal dimension,
D
f
, for a single-fractal analysis, and (b) the binding rate
coefficients,
k
1
and
k
2
, and the fractal dimensions,
D
f1
and
D
f2
, for a dual-fractal analysis
are given in
Table 10.9
. It is of interest to note that as the fractal dimension increases by a