Interdisciplinary research concerning the nature and properties of ceramic materials

Interdisciplinary research on properties of ceramic materials with emphasis on refractory surface insulatio

Interdisciplinary research concerning the nature and properties of ceramic materials Semiannual status report, 16 Jun. - 15 Dec. 1969

Research status reports in ceramic materials including chemical, mechanical, atomic, and molecular propertie

Multidisciplinary research activity in the materials sciences with emphasis on ceramic materials Semiannual status report, Jun. 16 - Dec. 15, 1967

Effects of various energy environments on zirconium-oxygen-carbon system, solid state ceramics, surface properties, and ceramic materials processin

Multidisciplinary research activity in the materials sciences with emphasis on ceramic materials Semiannual status report, 16 Dec. 1966 - 15 Jun. 1967

Ceramic materials science - chemical effects, surface phenomena, solid state ceramics, and processin

Structural mechanics of deformation and fracture Quarterly progress report

Structural mechanics of deformation and fracture - responses of model viscoelastic materials to impac

Nucleosynthesis in Primordial Hypernovae

We investigate the relationship between explosion energy and nucleosynthesis in Population III supernovae and provide nucleosynthetic results for the explosions of stars with progenitor masses of $15\,\mathrm{M}_\odot$, $20\,\mathrm{M}_\odot$, $30\,\mathrm{M}_\odot$, $40\,\mathrm{M}_\odot$, $60\,\mathrm{M}_\odot$, and $80\,\mathrm{M}_\odot$, and explosion energies between approximately $10^{50}$ erg and $10^{53}$ erg. We find that the typical abundance pattern observed in metal-poor stars are best matched by supernovae with progenitor mass in the range $15\,\mathrm{M}_\odot$ - $30\,\mathrm{M}_\odot$, and explosion energy of $\sim$ ($5$ - $10$) $\times$ $10^{51}$ erg. In these models, a reverse shock caused by jumps in density between shells of different composition serves to decrease synthesis of chromium and manganese, which is favourable to matching the observed abundances in metal-poor stars. Spherically symmetric explosions of our models with progenitor mass $\geq$ $40\,\mathrm{M}_\odot$ do not provide yields that are compatible with the iron-peak abundances that are typically observed in metal-poor stars, however, by approximating the yields that we might expect from these models in highly aspherical explosions, we find indications that explosions of stars $40\,\mathrm{M}_\odot$ - $80\,\mathrm{M}_\odot$ with bipolar jets may be good candidates for the enrichment sources of metal-poor stars with enhanced carbon abundances

SECOR observations in the Pacific

Geometric adjustment technique for Pacific SECOR observations based on least squares metho

Pair density waves and vortices in an elongated two-component Fermi gas

We study the vortex structures of a two-component Fermi gas experiencing a uniform effective magnetic field in an anisotropic trap that interpolates between quasi-one dimensional (1D) and quasi-two dimensional (2D). At a fixed chemical potential, reducing the anisotropy (or equivalently increasing the attractive interactions or increasing the magnetic field) leads to instabilities towards pair density waves, and vortex lattices. Reducing the chemical potential stabilizes the system. We calculate the phase diagram, and explore the density and pair density. The structures are similar to those predicted for superfluid Bose gases. We further calculate the paired fraction, showing how it depends on chemical potential and anisotropy.Comment: 6 pages, 3 figure

Global satellite triangulation and trilateration for the National Geodetic Satellite Program (solutions WN 12, 14 and 16)

A multi-year study and analysis of data from satellites launched specifically for geodetic purposes and from other satellites useful in geodetic studies was conducted. The program of work included theoretical studies and analysis for the geometric determination of station positions derived from photographic observations of both passive and active satellites and from range observations. The current status of data analysis, processing and results are examined