Embedding problems of division algebras

A finite group G is called admissible over a given field if there exists a central division algebra that contains a G-Galois field extension as a maximal subfield. We give a definition of embedding problems of division algebras that extends both the notion of embedding problems of fields as in classical Galois theory, and the question which finite groups are admissible over a field. In a recent work by Harbater, Hartmann and Krashen, all admissible groups over function fields of curves over complete discretely valued fields with algebraically closed residue field of characteristic zero have been characterized. We show that also certain embedding problems of division algebras over such a field can be solved for admissible groups.Comment: 19 page

Long wavelength semiconductor lasers development for infrared heterodyne applications

PbSnTe single crystals were grown in a new 3 zone furnace. Molecular beam epitaxy (MBE) growth parameters have been established, including beam flux vs. temperature, and growth rates and dopant vs. PbTe flux ratios for the various effusion sources involved. Lattice matching studies were conducted and doping studies were completed. Broad area Pb(1-x)Sn(x)Te double heterostructure lasers were fabricated with active layer compositions up to x equals 0.04 at percent Sn in the active layers. Electrical and optical test data are presented

Coulomb versus nuclear break-up of 11Be halo nucleus in a non perturbative framework

The 11Be break-up is calculated using a non perturbative time-dependent quantum calculation. The evolution of the neutron halo wave function shows an emission of neutron at large angles for grazing impact parameters and at forward angles for large impact parameters. The neutron angular distribution is deduced for the different targets and compared to experimental data. We emphasize the diversity of diffraction mechanisms, in particular we discuss the interplay of the nuclear effects such as the towing mode and the Coulomb break-up. A good agreement is found with experimental data.Comment: 9 figures, this paper was accepter in Nuclear Physics A on sept, 200

Cultural Resources Survey of the Towne Lake Detention Basin and Outfall

This report presents the results of an archeological survey of a proposed detention basin and outflow structures along Cypress Creek in Harris County, Texas. The project was sponsored by the Harris County Municipal Utility District (MUD) 502, and required consultation with the United States Army Corps of Engineers (USACE) under Section 404 of the Clean Water Act. This necessitated compliance with Section 106 of the National Historic Preservation Act (Section 106) and the Antiquities Code of Texas (ACT). Acacia Heritage Consulting conducted the archeological survey under Texas Antiquities Permit No. 8932. The survey involved visual inspection and subsurface testing in the form of 10 shovel tests and 4 backhoe trenches. Archeologists documented no artifacts or cultural material in any of the subsurface tests. No cultural material was observed on the surface either. Approximately one third of the project area was previously disturbed from vegetation clearing and soil borrowing, possibly to create an expedient flood detention basin. This report recommends that no further archeological work is warranted prior to construction of the Towne Lake detention basin and outfall. No artifacts were collected. All notes and records will be curated at the Center for Archaeological Studies in San Marco

Cultural Resources Survey along Mill Creek near Magnolia, Montgomery County, Texas

This report presents the results of an archeological survey for a 12-acre tract near Mill Creek, south of Farm-to-Market (FM) road 1488 in Montgomery County, Texas. The Montgomery County Municipal Utility District (MUD) 131 is proposing to build public utilities and make modifications to a tributary of Mill Creek on the 12-acre property, which requires consultation with the United States Army Corps of Engineers (USACE) under Section 404 of the Clean Water Act. This also necessitates compliance with Section 106 of the National Historic Preservation Act (Section 106) and the Antiquities Code of Texas (ACT). Acacia Heritage Consulting conducted the archeological survey under Texas Antiquities Permit No. 9007. The survey involved visual inspection and subsurface testing in the form of eight shovel tests. Archeologists documented no artifacts or cultural material in any of the subsurface tests. No cultural material was observed on the surface either. The majority of the project area had recently been disturbed from tree removal and burning as part of the site preparation work done by the developer. As a result, surface visibility was nearly 100 percent across the project area and no artifacts or archeological materials were observed anywhere on the surface of this property. This report recommends that no further archeological work is warranted prior to construction of the 12-acre property. No artifacts were collected. All notes and records will be curated at the Center for Archaeological Studies in San Marcos