High-temperature fracture strength and compressive creep of an electrodischarge-machinable composite, Al{sub 2}O{sub 3}-30.9 vol.% SiC whiskers-23 vol.% TiC particles have been studied to 1200 C and 1450 C, respectively, in inert atmosphere. Microstructures of fractured and deformed specimens were examined by scanning and transmission electron microscopy. Fast fracture occurred at T {le} 1200 C. Steady-state creep was achieved for T > 1350 C at stresses < 80 MPa, with the rate-controlling mechanism being partially unaccommodated grain-boundary sliding, with a stress exponent of {approx}1 and an activation energy of {approx}470 kJ/mol.

The purpose of the studies conducted at Argonne National Laboratory is to understand the impact mental representational systems have in identifying how user comfort parameters influence how information is to best be presented. By understanding how each individual perceives information based on the three representational systems (visual, auditory and kinesthetic modalities), it has been found that a different approach must be taken in the design of interfaces resulting in an outcome that is much more effective and representative of the users mental model. This paper will present current findings and future theories to be explored.

Experimental Breeder Reactor-II (EBR-II), an experimental sodium cooled fast breeder reactor located at Argonne National Laboratory-West (ANL-W), was shut down in 1994, and has since been defueled in preparation for final plant closure. Approximately 100,000 gallons of liquid sodium is contained in the primary and secondary cooling systems of the EBR-II plant. The liquid sodium must be drained from the reactor systems during closure of the plant to place the reactor plant in an industrially and radiologically safe condition for long term storage or dismantlement. Because the liquid sodium is a listed waste under the Resource Conservation Recovery Act (RCRA), it is not suitable for disposal. It therefore must be transferred to the Sodium Process Facility (SPF), which is located approximately nine hundred feet from the reactor complex, where it will be processed into a non-reactive form, suitable for land disposal in Idaho. To facilitate this transfer, a heated pipeline for carrying liquid sodium metal from EBR-II to the SPF was designed and installed. The SPF was originally designed and built to process primary sodium from the Fermi-1 reactor. The sodium is stored at ANL-W in 55 gallon drums. Design of the SPF did not originally accommodate processing of EBR-II …

Proteins are remarkable molecular machines that are essential for life. They can do many things ranging from the precise control of blood clotting to synthesizing complex organic compounds. Pictures of protein molecules are in high demand in biotechnology because they are important for applications such as drug discovery and for engineering enzymes for commercial use. X-ray crystallography is the most common method for determining the three-dimensional structures of protein molecules. When a crystal of a protein is placed in an X-ray beam, scattering of X-rays off the ordered molecules produces a diffraction pattern that can be measured on a position-sensitive CCD or image-plate detector. Protein crystals typically contain thousands of atoms and the diffraction data are generally measured to relatively low resolution. Consequently the direct methods approaches generally cannot be applied. Instead, if the crystal is modified by adding metal atoms at specific sites or by tuning the wavelength of the X-rays to cross an absorption edge of a metal atom in the crystal, then the information from these additional measurements is sufficient to first identify the /locations of the metal atoms. This information is then used along with the diffraction data to make a three-dimensional picture of electron densities. …

Lawrence Livermore National Laboratory (LLNL) examined the waste stream from a water jet cutting operation, to evaluate the possible reuse of waste garnet sand. The sand is a cutting agent used to shape a variety of materials, including metals. Nearly 70,000 pounds of waste sand is generated annually by the cutting operation. The Environmental Protection Department evaluated two potential reuses for the spent garnet sand: backfill in utility trenches; and as a concrete constituent. In both applications, garnet waste would replace the sand formerly purchases by LLNL for these purposes. Findings supported the reuse of waste garnet sand in concrete, but disqualified its proposed application as trench backfill. Waste sand stabilized in ac concrete matrix appeared to present no metals-leaching hazard; however, unconsolidated sand in trenches could potentially leach metals in concentrations high enough to threaten ground water quality. A technical report submitted to the San Francisco Bay Regional Water Quality Control Board was reviewed and accepted by that body. Reuse of waste garnet cutting sand as a constituent in concrete poured to form walkways and patios at LLNL was approved.