Behaviour of239,240Pu and241Am in the Baltic Sea; Measurements and interpretation in 1980–1984

Concentrations of^239,240Pu and²⁴¹Am in filtered seawater, particulate fraction and sediment were measured. Methods for determination of these nuclides were critically chequed and a new rapid method for²⁴¹Am in sediment was developed. Due to seasonal variation a significant decrease of plutonium and americium concentrations in surface water takes place in summer. Americium is more efficiently associated with particulate matter than plutonium. From May 1980 to September 1984 soluble plutonium in the water was reduced to about half. The residence half-time of^239,240Pu in the water of Baltic Sea is of the order of 5 years. About similar concentrations of^239,240Pu and²⁴¹Am were found in particulates in water as in the surface layer of the sediment. The average K_d-values for plutonium and americium were 10⁵ and 10⁵–10⁶ ml/g, respectively.     

Connections Between Single-Level and Bilevel Multiobjective Optimization

The relationship between bilevel optimization and multiobjective optimization has been studied by several authors, and there have been repeated attempts to establish a link between the two. We unify the results from the literature and generalize them for bilevel multiobjective optimization. We formulate sufficient conditions for an arbitrary binary relation to guarantee equality between the efficient set produced by the relation and the set of optimal solutions to a bilevel problem. In addition, we present specially structured bilevel multiobjective optimization problems motivated by real-life applications and an accompanying binary relation permitting their reduction to single-level multiobjective optimization problems.     

Using a time-delay and integration camera at a non-zero viewing angle under vibration conditions

The use of a TDI camera is restricted to cases of viewing from the direction of the surface normal. Our previous work indicated that a TDI camera can be used with viewing angles up to 30° from the surface normal which extends the usability of TDI for visual inspection applications. The objective of this paper is to examine the use of a TDI camera at a non-zero viewing angle under vibration conditions. The effects caused by vibration of the surface to be viewed become critical when using a TDI camera at non-zero viewing angles. A method of approximating the TDI performance under vibration conditions was determined and evaluated experimentally. The resulting measurements support the approximating method developed here.     

Semi-transparent hadrons from multi-channel absorption effects

We analyze the absorption structure of diffractive dissociation discussing simultaneously the elastic and inelastic processes. This approach is motivated by their close interdependence and mutual influence. We show that the results differ significantly from the standard picture of elastic scattering. In particular, protons are shown to have very rich internal structure coupling both to “black” and “transparent” diffractive scattering eigenstates. Proton matter distribution may well be very different from that suggested by the analysis of Chou and Yang. Finally, the indicated asymptotic behaviour is that of a “grey” instead of a “black” disc limit.     

Measurement of the spin parameters A and Ann in pp elastic scattering in the 1–3 GeV/c region

We have measured the asymmetry parameter A and the spin correlation parameter A_nn in pp elastic scattering, using the Argonne ZGS polarized proton beam and a polarized proton target. Angular distributions of A and A_nn for |t| ? 0.2 (GeV/c)²wereobtainedateightmomentabetween 1.10 and 2if2.75 GeV/c. We find significant structure in both the energy and t-dependence of A_nn at these energies. At p_lab ≈ 1.34 GeV/cA_nn reaches a very large value of about 0.8–0.9 near θ_cm = 90°.