Dose constant

Auger-L = L-shell Auger electron b ce-K = K-shell conversion electron yray c A = Equilibrium absorbed — dose constant... 

The pseudo-first order rate constant (k1) is sometimes referred to as a dose constant. Because continuous irradiations are generally performed at constant dose rate, it may also be expressed with respect to absorbed radiation dose (kGy () rather than time (s ). It then represents the concentration of solute removed per unit dose. 

The use of the pseudo-first-order dose constant assumes that the removal of solutes is exponential, which is common in waste-treatment applications [10]. For example, the concentration of OH calculated from Eq. (16) for absorbed doses between 1 and 10 kGy is 0.28 to 2.8 mM. Under these conditions the loss of the solutes (at typical solute concentrations in the micromolar range) is pseudo-first-order, with respect to absorbed dose, and can be described by the following ... 

Alternately, for a solute decreasing in concentration in exponential fashion, G at any dose may be found from the empirical dose constant and Eq. (26) ... 

Table 4 Pseudo-First-Order Dose Constants for the e-Beam Irradiation of Aromatic Compounds in Water (1) and Wastewater (2)... 

In can be seen from Table 4 that wastewater has similar or lower dose constants for solute degradation than potable water. This was expected due to the higher concentrations of radical scavengers in wastewater. Decomposition of all the studied solutes occurred with higher efficiency at low solute concentrations. At higher solute concentrations, only benzene showed a decreased dose constant in wastewater. This may indicate successful competition for radicals by the higher solute concentration. 

Gehringer irradiated TCE contaminated waters in the presence and absence of ozone [52]. The use of ozone dramatically increased the rate of 100 ppb TCE decomposition, as shown in Fig. 6 and in Table 7. It was also found that the Z)10 (and thus dose constant) values were independent of initial TCE concentration over a wide range, indicating that the mechanism of decomposition was constant. Thus, the factors for reduction in Dw shown in Table 7 are useful predictive process parameters. 

Many of the larger sizes of boom sprayer used to treat arable crops in Northern European conditions have a control system that adjusts the volume output rate depending upon measured forward speed, so as to keep the delivered dose constant over a range of operating speeds. 

The average P particle energy of In-114m is 773 keV with a total equilibrium dose constant of 1.66 rad g pCi h Isomeric transition of to In takes place with... 

O Table 47.4 lists examples of absorbed fractions for liver as the source organ. For determination of the absorbed dose by the form (O 47.18) additionally the equilibrium dose constant (A,) is to be used. The constant depends on the y-yield and -energy emitted by the radionuclide and the value of Tc takes zl = 7.2 x 10 Gy h per MBq kg . ... 

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