The early Holocene final drainage of glacial Lake Minong is documented by 21 OSL ages on quartz sand from parabolic dunes and littoral terraces and one radiocarbon age from a lake sediment core adjacent to mapped paleoshorelines in interior eastern Upper Michigan. We employ a simple model wherein lake-level decline exposes unvegetated littoral sediment to deflation, resulting in dune building. Dunes formed subsequent to lake-level decline prior to stabilization by vegetation and provide minimum ages for lake-level decline. Optical ages range from 10.3 to 7.7 ka; 15 ages on dunes adjacent to the lowest Lake Minong shoreline suggest final water-level decline ∼ 9.1 ka. The clustering of optical ages from vertically separated dunes on both sides of the Nadoway–Gros Cap Barrier around 8.8 ka and a basal radiocarbon date behind the barrier (8120 ± 40 14C yr BP [9.1 cal ka BP]) support the hypothesis that the barrier was breached and the final lake-level drop to the Houghton Low occurred coincident with (1) high meltwater flux into the Superior basin and (2) an abrupt, negative shift in oxygen isotope values in Lake Huron.

We discuss the role of Configuration Interaction (CI) and the influence of the number ofconfigurations taken into account in the calculations of nickel and iron spectralopacities provided by the OPAC international collaboration, including statisticalapproaches (SCO, CASSANDRA, STA), detailed accounting (OPAS, LEDCOP, OP, HULLAC-v9) orhybrid method (SCO-RCG). Opacity calculations are presented for a temperature T of 27.3 eVand a density of 3.4 mg/cm3, conditions relevant for pulsating stellarenvelopes.

Recent studies by a number of research groups have shown that the structure of epitaxial BiFeO3 (BFO) films changes drastically as a function of substrate-induced biaxial compression, with the crystal structure changing from one being nearly rhombohedral (R-like) to one being nearly tetragonal (T-like), where the “T-like” structure is characterized by a highly enhanced c/a ratio of out-of-plane c to in-plane a lattice parameters. In this work, we show that the critical compressive strain σc necessary to induce this transition can be reduced significantly by substituting 10% Ba for Bi [Bi0.9Ba0.1FeO3−δ (BBFO)] and that the “T-like” phase in both BBFO and BFO is stable up to the decomposition temperatures of the films in air. Furthermore, our results show that the BBFO solid solution shows clear ferromagnetic properties in contrast to its undoped BFO counterpart.

Owing to their sub-Sahelian climate, the Cape Verde Islands, lying off the coast of West Africa, experience severe problems of soil erosion and surface-water loss. Thus the development of this country has included widescale planting of trees, mainly Prosopis juliflora, and the building of contour walls and small dams. Agroforestry species are being tested for both erosion control and the production of wood and timber. The conservation of native crop species, and the use of integrated pestcontrol, have been given priority in Cape Verde's agricultural development.

A new fully three dimensional (3D) ballistic deposition simulator 3D-FILMS has been developed for the modeling of thin film deposition and structure. The simulator may be implemented using the memory resources available to workstations. In order to illustrate the capabilities of 3D-FILMS, we apply it to the growth of engineered porous thin films produced by the technique of GLancing Angle Deposition (GLAD).

We study the ring of invariant Laurent polynomials associated to the action of a finite diagonal group G on the symmetric algebra of a vector space over a field F. Here the characteristic p of the field F necessarily does not divide the order q = |G| of the group, so G is said to be non-modular. For certain representations of such groups, we can characterise generators of the ring of invariant polynomials in the original symmetric algebra, extending results of Campbell, Hughes, Pappalardi and Selick. In particular we obtain a recursive formula for the number of minimal generators for these rings of invariants.

The in situ epitaxial growth of Bi‐Sr‐Ca‐Cu‐O films by molecular beam epitaxy (MBE) is reported. The suitability of ozone to the MBE growth of cuprate superconductors is discussed. Molecular beams of the constituents were periodically shuttered to grow various Bi2Sr2Can‐1CunOx phases, including 2201, 2212,2223,2245, and layered mixtures of these phases. Using these techniques a superconducting film with TC onset near 100 K and Tc (ρ=0) of 81 K was achieved under entirely MBE conditions (Pchamber≤xl0‐4 Torr during growth and cooling). The films are smooth on an atomic scale. The results demonstrate the ability of shuttered MBE growth to selectively grow Bi2Sr2Can‐1CunOx phases.