Configuration Interaction calculations of positron binding to Be(3Po)

The Configuration Interaction method is applied to investigate the possibility of positron binding to the metastable beryllium (1s^22s2p 3Po) state. The largest calculation obtained an estimated energy that was unstable by 0.00014 Hartree with respect to the Ps + Be^+(2s) lowest dissociation channel. It is likely that positron binding to parent states with non-zero angular momentum is inhibited by centrifugal barriers.Comment: 12 pages, 2 figures, Elsevier tex format, In press Nucl.Instrum.Meth.Phys.Res.B positron issu

Convergence of the partial wave expansion of the He ground state

The Configuration Interaction (CI) method using a very large Laguerre orbital basis is applied to the calculation of the He ground state. The largest calculations included a minimum of 35 radial orbitals for each l ranging from 0 to 12 resulting in basis sets in excess of 400 orbitals. The convergence of the energy and electron-electron delta-function with respect to J (the maximum angular momenta of the orbitals included in the CI expansion) were investigated in detail. Extrapolations to the limit of infinite in angular momentum using expansions of the type Delta X_J = A_X/(J+1/2)^p + B_X/(J+1/2)^(p+1) + ..., gave an energy accurate to 10^(-7) Hartree and a value of accurate to about 0.5%. Improved estimates of and , accurate to 10^(-8) Hartree and 0.01% respectively, were obtained when extrapolations to an infinite radial basis were done prior to the determination of the J -> infty limit. Round-off errors were the main impediment to achieving even higher precision since determination of the radial and angular limits required the manipulation of very small energy and differences.Comment: 11 pages, 7 figures, revtex format, submitted to Int.J.Quantum Chemistr

\u3cem\u3eThe U-Boat Hunters: The Royal Canadian Navy and the Offensive Against Germany’s Submarines\u3c/em\u3e by Marc Milner [Review]

Review of Marc Milner, The U-Boar Hunters: The Royal Canadian Navy and the Offensive Against Germany\u27s Submarines. Toronto: University of Toronto Press, 1994

BALANCING POLICY FOR ENVIRONMENT AND ECONOMIC DEVELOPMENT

Environmental Economics and Policy,

A BARGAINING FRAMEWORK FOR THE GLOBAL COMMONS

The global commons represents a class of environmental problems that require international cooperation. Global environmental problems arise because the actions of some individuals or governments in one location hold serious implications for individuals and governments in other locations. There are global environmental policy problems because adversely-affected individuals (and governments) attempt to alter the behaviors of those responsible for global pollution. We develop a framework with which to analyze such global environmental problems. Our goal is to craft a resource management policy that will satisfy both those who seek a change and those who prefer the current situation. This environmental incentive policy will align the interests of the two parties. Incentive alignment is the policy problem in the global commons. That is, we must find ways to align interests through realigning incentives for individual and group behaviors.Environmental Economics and Policy,

Land Use Policy as Volitional Pragmatism

Land-use conflicts highlight several myths about property rights. The central myth is that property rights are linked to natural rights, that property rights are durable and unchanging, and that any interference with these property rights requires public compensation. However, particular settings and circumstances lead to conflicting rights claims which the courts must sort through to determine where the more compelling rights claim resides. Situations are not protected because they have property rights. Rather, those situations found worthy of protection by the courts acquire the status of a property right. Property rights are not discovered, but are created by the courts. Applied economists must build models of property rights conflicts predicated upon an epistemology of volitional pragmatism.Land Economics/Use,

Convergence of an s-wave calculation of the He ground state

The Configuration Interaction (CI) method using a large Laguerre basis restricted to l = 0 orbitals is applied to the calculation of the He ground state. The maximum number of orbitals included was 60. The numerical evidence suggests that the energy converges as Delta E^N approx A/N^(7/2) + B/N^(8/2) + >... where N is the number of Laguerre basis functions. The electron-electron delta-function expectation converges as Delta delta^N approx A/N^(5/2) + B/N^(6/2) + ... and the variational limit for the l = 0 basis is estimated as 0.1557637174(2) a_0^3. It was seen that extrapolation of the energy to the variational limit is dependent upon the basis dimension at which the exponent in the Laguerre basis was optimized. In effect, it may be best to choose a non-optimal exponent if one wishes to extrapolate to the variational limit. An investigation of the Natural Orbital asymptotics revealed the energy converged as Delta E^N approx A/N^6 + B/N^7 + ... while the electron-electron delta-function expectation converged as Delta delta^N approx A/N^4 + B/N^5 + >... . The asymptotics of expectation values other than the energy showed fluctuations that depended on whether $N$ was even or odd.Comment: 12 pages, 10 figures, revtex format, submitted to Int.J.Quantum Chemistr