Descriptions of new fishes from Panama

The following preliminary descriptions are of new fishes obtained by the authors during their first season's work on the Biological Survey of the Canal Zone, the ichthyological work of which is being conducted cooperatively by the Field Museum of Natural History and the Smithsonian Institution. (2 page document

Discrete Hubbard-Stratonovich transformations for systems with orbital degeneracy

A discrete Hubbard-Stratonovich transformation is presented for systems with an orbital degeneracy $N$ and a Hubbard Coulomb interaction without multiplet effects. An exact transformation is obtained by introducing an external field which takes $N+1$ values. Alternative approximate transformations are presented, where the field takes fewer values, for instance two values corresponding to an Ising spin.Comment: 4 pages, revtex, 1 eps figure, additional material avalable at http://librix.mpi-stuttgart.mpg.de/docs/ANDERSEN/fullerene

Surface nutrient enrichment in a long-term zero-till soil

Non-Peer Reviewe

Relationships among crop yield, protein, soil properties, and response to nitrogen fertilizer application in an undulating landscape in south central Saskatchewan

Non-Peer Reviewe

Relationship of crop yield and protein content to soil properties in an undulating landscape in south central Saskatchewan

Non-Peer Reviewe

An Unusual Root Injury on Jersey-type Sweetpotatoes in 1962

Volume: 4

Underwater radiated noise levels of a research icebreaker in the central Arctic Ocean

U.S. Coast Guard Cutter Healy\u27s underwater radiated noise signature was characterized in the central Arctic Ocean during different types of ice-breaking operations. Propulsion modes included transit in variable ice cover, breaking heavy ice with backing-and-ramming maneuvers, and dynamic positioning with the bow thruster in operation. Compared to open-water transit, Healy\u27s noise signature increased approximately 10 dB between 20 Hz and 2 kHz when breaking ice. The highest noise levels resulted while the ship was engaged in backing-and-ramming maneuvers, owing to cavitation when operating the propellers astern or in opposing directions. In frequency bands centered near 10, 50, and 100 Hz, source levels reached 190–200 dB re: 1 μPa at 1 m (full octave band) during ice-breaking operations

Comparison of Two Bulk Energy Approaches for the Phasefield Modeling of Two-variant Martensitic Laminate Microstructure

The unusual thermomechanical properties of shape memory alloys are closely connected to the formation and evolution of their microstructure. At lower temperatures, shape memory alloys typically consists of martensitic laminates with coherent twin boundaries. We propose a large strain phasefield model for the formation and dissipative evolution of such two-variant martensitic twinned laminate microstructures. Our model accounts for the coherence-dependence of the interface energy density and contains a Ginzburg-Landau type evolution equation. We introduce two conceptually different modeling approaches for the regularized bulk energy, i.e. external and internal mixing. We construct a suitable gradient-extended incremental variational framework for the proposed formulation and discretize it by use of finte elements. Finally, we demonstrate the modeling capabilities of our formulation by means of two-dimensional finite element simulations of laminate formation in two-phasic martensitic CuAlNi and compare the energetic modeling properties of the two proposed bulk energy approaches