Section time—upper-middle

Figure 3a. Leach rate as a function of time—upper-middle glass section...

Figure 4, Leach rate as a function of time and glass section for Cs and (--------bottom section (- -), upper-middle section (-top section.

Travel time and the longitudinal Fickian transport coefficient can also be evaluated from a continuous injection experiment, in which injection of tracer is initiated at time f=0 at a rate sufficient to establish a chemical concentration Co at the point of injection. Such an experiment is discussed for groimdwater in Section 3.2.5 the equation describing concentrations resulting from a continuous injection in a river is conceptually identical to Eq. (3.18). Equivalently, the injection of tracer can be described as mass per cross-sectional area per imit time (M), in which case the equation presented in the upper middle panel of Fig. 3.19 can also be used for a river, with porosity n equal to 1. 

Noon values are J43a = 4 x 10 and J43b = 1 x 10. The value of the rate coefficient for R48, K48 = 1.5 x 10 [Morris and Niki (177)], has already been discussed (see Section IV.D.2). In the lower troposphere, the two loss paths—photolysis and OH reaction—are comparable, while in the middle and upper troposphere, where n(OH) drops off, photolysis is dominant. At the same time, the destruction of CH by OH, which has a large activation energy, slows greatly, resulting in a significant reduction in the production of H2C=0 and therefore in n(H2C=0) itself. 

Fig. 2. Section of GCxGC-TOFMS TIC-chromatogram of Ips nitidus frass extract Ik range 900-1100 visualized as contour plot (with n-alkane standards in the upper part) and as 3D-view, respectively. Each spot in the upper 2D-chromatographic plane represents a single compound, the intensity of which is colour coded. White, yellow and red represent low, middle and high intensity, respectively. On the plane, the individual compounds are distributed based on their volatilities (X-axis) and polarities (Y-axis). The more polar and less volatile compounds elute at later retention times. The numbers indicate the identity of fhe compounds as lisfed in Table 1.

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