This work estimates the critical activity concentrations of 90Sr and the alpha-emitting isotopes of Pu, Am and Cm in soil and pasture vegetation that would be required to exceed the action levels for foodstuffs recommended by the IAEA. The results show that the common detection limits for environmental analysis of these nuclides may be increased by orders of magnitude if the aim of the analysis...

which commute with the flow defined by (0.1) (we set τ1 = z and τ2 = τ). The important fact is that the right hand sides Pn of equations (0.2) are polynomials in v and its derivatives, i.e., differential polynomials in v. This fact allows us to treat the KdV hierarchy (0.2) in the following way. Consider the ring R = C[v]n≥0 of polynomials in the variables v (n) (we shall write v for v(0)). Let...