We are developing new software component technology for high-performance parallel scientific computing to address issues of complexity, re-use, and interoperability for laboratory software. Component technology enables cross-project code re-use, reduces software development costs, and provides additional simulation capabilities for massively parallel laboratory application codes. The success of our approach will be measured by its impact on DOE mathematical and scientific software efforts. Thus, we are collaborating closely with library developers and application scientists in the Common Component Architecture forum, the Equation Solver Interface forum, and other DOE mathematical software groups to gather requirements, write and adopt a variety of design specifications, and develop demonstration projects to validate our approach. Numerical simulation is essential to the science mission at the laboratory. However, it is becoming increasingly difficult to manage the complexity of modern simulation software. Computational scientists develop complex, three-dimensional, massively parallel, full-physics simulations that require the integration of diverse software packages written by outside development teams. Currently, the integration of a new software package, such as a new linear solver library, can require several months of effort. Current industry component technologies such as CORBA, JavaBeans, and COM have all been used successfully in the business domain to reduce software development …

At 650 C, Si freely intermixes with Ge in the dome islands causing a reduction in the strain of the islands and an increase in island size. The shape reversal of Ge/Si domes to pyramids is investigated by analysis of the strain and size changes that occur on an island by island basis. This was carried out for anneal times of 0, 20, 40 and 60 minutes. Transition islands were observed consistent with previous work, which are partially domes and partially pyramids. These islands demonstrated a strain gradient, having a slightly lower strain on the side that has transformed to a pyramid. Cross-sectional STEM was then used to show that this strain gradient is associated with a non-uniform Si intermixing in the islands.

The microrheology of dry soap foams subjected to large, quasistatic, simple shearing deformations is analyzed. Two different monodisperse foams with tetrahedrally close-packed (TCP) structure are examined: Weaire-Phelan (A15) and Friauf-Laves (C15). The elastic-plastic response is evaluated by calculating foam structures that minimize total surface area at each value of strain. The minimal surfaces are computed with the Surface Evolver program developed by Brakke. The foam geometry and macroscopic stress are piecewise continuous functions of strain. The stress scales as T/V{sup 1/3} where T is surface tension and V is cell volume. Each discontinuity corresponds to large changes in foam geometry and topology that restore equilibrium to unstable configurations that violate Plateau's laws. The instabilities occur when the length of an edge on a polyhedral foam cell vanishes. The length can tend to zero smoothly or abruptly with strain. The abrupt case occurs when a small increase in strain changes the energy profile in the neighborhood of a foam structure from a local minimum to a saddle point, which can lead to symmetry-breaking bifurcations. In general, the new foam topology associated with each stable solution branch results from a cascade of local topology changes called T1 transitions. Each T1 cascade produces …

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X-ray absorption spectroscopy (XAS) has been used to investigate the structure and valence of thorium (Th{sup 4+}) and uranyl (UO{sub 2}{sup 2+}) cations exchanged into two classes of microporous aluminosilicate minerals: zeolites and smectite clays. XAS is also employed to examine the fate of the exchanged cations after modification of the mineral surface using self-assembled organic films and/or exposure to hydrothermal conditions. These treatments serve as models for the forces that ultimately determine the chemical fate of the actinide cations in the environment. The speciation of the cations depends on the pore size of the aluminosilicate, which is fixed for the zeolites and variable for the smectites.

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO provided information on the Department of Justice's (DOJ) policy and guidance for selecting structured settlement brokers, focusing on: (1) the policies and guidance for selecting structured settlement brokers used by DOJ and six selected agencies; and (2) a list of the structured settlement brokerage companies used by DOJ and the number of settlements awarded to each company since May 1997."

The authors have studied the temperature stability of M41S class siliceous mesoporous materials loaded with carbonaceous material by temperature programmed small-angle X-ray scattering (TPSAXS) techniques. Results show the thermal structural instability of large pore pure silica sieve material with carbonaceous material (such as coal extracts) occluded within the pores of mesoporous 31 {angstrom} M41S materials. Unfilled pore M41S materials do not show thermal-related structural instability.

Radioactive wastes from processing irradiated uranium fuels have been stored as alkaline slurries in underground tanks at the Hanford Site. Single-shell tanks (SST) and double-shell tanks (DST) of various sizes were used for waste storage. Of the total 177 tanks, there are 28 DSTs. DSTs are located in AN, AP, AW, AY, AZ, and SY tank farms in the 200 East (200E) and 200-West (200W) Areas. The storage capacities of the DSTs vary from 980,000 to 1,140,000 gal. DSTs are designed and constructed as an integral steel structure, i.e., an inner shell within an outer shell, so that any leak from the inner shell is confined within the annulus without impacting the environment. The inner shell provides primary containment for the wastes and the outer shell provides secondary containment in the form of an annulus. The annulus of a DST is equipped with a pump pit, leak detection probes, and other accessories. The existing annulus pumps in the DSTs need to be revamped with a new system to reduce operating costs and reduce the time to deploy a pumping system. The new pumping system will minimize the likelihood of a release of waste into the environment; improve capability of waste …

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RL30437: Water Quality Initiatives and Agriculture Claudia Copeland Specialist in Resources and Environmental Policy Resources, Science, and Industry Division February 16, 2000 ABSTRACT Agriculture, which has been a relatively minor component of national water quality policies and programs, especially regulatory policies, is currently involved with several recent Administration water quality initiatives. This report provides background on three ongoing initiatives with potential to affect agriculture: the Clean Water Action Plan, the Unified National Animal Feeding Operations Strategy, and implementation of the Total Maximum Daily Load (TMDL) provisions of the Clean Water Act. The report includes a glossary of terms and a chronology of the key deadlines in the initiatives and identifies other CRS reports for additional information. It will be updated as developments warrant. Summary Congress most recently enacted amendments to the nation's water quality law, the Clean Water Act (CWA), in 1987. But national water quality policy has evolved in the intervening years, as a result of implementation of the 1987 amendments and related Administration initiatives intended to fulfill the requirements and meet the goals and objectives of the Act. Agriculture, which has been a relatively minor component of national water quality policies and programs, especially regulatory policies, is now …