Regulating nonlinear environmental systems under Knightian uncertainty

uncertainty;environment;regulations

Cone-manifolds and the density conjecture

We give an expository account of our proof that each cusp-free hyperbolic 3-manifold M with finitely generated fundamental group and incompressible ends is an algebraic limit of geometrically finite hyperbolic 3-manifolds.Comment: 19 Pages, 2 figures; to appear, proceedings of the Warwick Conference: Kleinian Groups and Hyperbolic 3-Manfiolds, September 200

Optimal phosphorus loading for a potentially eutrophic lake

dynamic programming;sustainable development;ecology

Alternate methods of applying diffusants to silicon solar cells

Low-melting phosphate and borate glasses were screen printed on silicon wafers and heated to form n and p junctions. Data on surface appearance, sheet resistance and junction depth are presented. Similar data are reported for vapor phase transport from sintered aluminum metaphosphate and boron-containing glass-ceramic solid sources. Simultaneous diffusion of an N(+) layer with screen-printed glass and a p(+) layer with screen-printed Al alloy paste was attempted. No p(+) back surface field formation was achieved. Some good cells were produced but the heating in an endless-belt furnace caused a large scatter in sheet resistance and junction depth for three separate lots of wafers