A geometrical multigrid method for solving the linearized matrix equations arising from node-on-face three-dimensional finite element contact is described. The development of an efficient implementation of this combination that minimizes both the memory requirements and the computational cost requires careful construction and storage of the portion of the coarse mesh stiffness matrices that are associated with the contact stiffness on the fine mesh. The multigrid contact algorithm is parallelized in a manner suitable for distributed memory architectures: results are presented that demonstrates the scheme's scalability. The solution of a large contact problem derived from an analysis of the factory joints present in the Space Shuttle reusable solid rocket motor demonstrates the usefulness of the general approach.

Atmospheric aberrations reduce the resolution and contrast in surveillance images recorded over horizontal or slant paths. This paper describes our recent horizontal and slant path imaging experiments of extended scenes as well as the results obtained using speckle imaging. The experiments were performed with an 8-inch diameter telescope placed on either a rooftop or hillside and cover ranges of interest from 0.5 km up to 10 km. The scenery includes resolution targets, people, vehicles, and other structures. The improvement in image quality using speckle imaging is dramatic in many cases, and depends significantly upon the atmospheric conditions. We quantify resolution improvement through modulation transfer function measurement comparisons.

This report documents completion of Milestone A.4-1 "Issue Tank Lay-Up Strategies for WVDP Final Report," in Technical Task Plan RL3-WT21A, "Post-Retrieval and Pre-Closure HLW Tank Lay-Up." This task was a collaborative effort among Pacific Northwest National Laboratory, Jacobs Engineering Group Inc., and West Valley Nuclear Services. The primary objective of the overall task was to develop and evaluate conceptual strategies for preclosure lay-up of the two large high-level waste storage tanks at the West Valley Demonstration Project.

Documents completion of Milestone A.2-1, "Issue Tanks Lay-Up Strategies for WVDP," in Technical Task Plan RL30WT21A, "Post-Retrieval and Pre-Closure HLW Tank Lay-Up." This task is a collabrative effort among Pacific Northwest National Laboratory, Jacobs Engineering Group Inc., and West Valley Nuclear Servies. The primary objective of the overall task is to develop and evaluate conceptual strategies for preclosure lay-up of the two large high-level waste (HLW) storage tanks at the West Valley Demonstration Project (WVDP). Functions and requirements for tank lay-up were developed and previously documented in "Functions and Requirements for WVDP Lay-Up". Theses functions and requirements will serve as decision criteria to support selection of a strategy for safe and cost-effective lay-up of the HLW tanks.

Isotopically enriched xenon isotopes are ideal for tracking the flow of relatively large volumes of groundwater. Dissolved noble gas tracers behave conservatively in the saturated zone, pose no health risk to drinking water supplies, and can be used with a large dynamic range. Different Xe isotopes can be used simultaneously at multiple recharge sources in a single experiment. Results from a tracer experiment at a California water district suggests that a small fraction of tracer moved from the recharge ponds through the thick, unconfined, coarse-grained alluvial aquifer to high capacity production wells at a horizontal velocity of 6 m/day. In contrast, mean water residence times indicate that the average rate of transport is 0.5 to 1 m/day.

This report documents the preliminary needs assessment of high-level waste (HLW) tank lay-up requirements and considerations for the Hanford Site, Idaho Naitonal Engeineering and Environmental Lab (INEEL), Savannah River Site (SRS) and Oak Ridge Reservation (ORR). This assessment includes the development of a high-level requirements and considerations list that evolved from work done for the West Valley Demonstration Project (WVDP) earlier in fiscal year (FY) 2001, and is based on individual site conditions and tank retrieval/tank closure schedules. Because schedules are continually subject to change, this assessment is considered preliminary and needs review and validation by the individual sites. The lay-up decision methodology developed for WVDP was based on standard systems engineering principles, and provided a structured framework for producing an effective, technically-defensible lay-up strategy.

During fiscal year (FY) 2001 as part of a Tanks Focus Area strategic intiative, tank lay-up options were developed and evaluated for the two high-level waste (HLW) storage tanks at the West Valley Demonstration Project. As follow-on task, a list of key waste tank contacts throughout the US Department of Energy complex was developed. Visits were then made to the primary DOE sites with radioactive waste storage tanks to discuss the concept and applicablility of tank lay-up. This report documents the results of individual discussions with tank closure staff at the four DOE Sites concerning tank closure status and plans as well as lay-up options and activities.

Jacobs Engineering Group Inc. is developing and evaluating high-level waste (HLW) tank lay-up strategies in collaboration wiht the Pacific Northwest National Laboratory (PNNL) and West Valley Nuclear Services Company. This work is included in the US Department of Energy (DOE) Tanks Focus Areas (TFA) Technical Test Plan RL3-WT21A, "Post-Retrieval and Pre-Closure HLW Tank Lay-Up".

Documents completion of Milestone A.3-1, "Issue Decision Plan for WVDP Tank Lay-Up," in Technical Task Plan RL30WT21A, "Post-Retrieval and Pre-Closure HLW Tank Lay-Up." This task is a collaborative effort among, Pacific Northwest National Laboratory, Jacobs Engineering Group Inc., and West Valley Nuclear Services. Thi primary objective of the overall task is to develop and evaluate conceptual strategies for preclosure lay-up of the two large high-level waste storage tanks at the West Valley Demonstration Project. Functions and requirments for tank lay-up were developed and previously documented in "Functions and Requirements for WVDP Lay-Up". These functions nad requirments served as the basis for cristeria to evaluate potential aly-up options documented in "West Valey High-Level Waste Tank Lay-Up Strategies".

This document provides background information and a list of questions to be addressed during an information-gathering visit by Jacobs Engineering Group Inc personnel. Jacobs has been funded by the Tanks Focus Area to complete a task "Pre-closure Interim Tanks Maintenance." The overall objective of this task is to develop a central informaion center of site conditions, site requirements, alternative technical and other approaches, closure plans and activities, regulatory drivers and methodolgies for decision-making to assist site decisdion-makers in teh evaluation of alternative high-level waste (HLW) tank lay-up configureations. Lay-up is the term used for the period between intial decontamination and decommissioning of the tanks and final closure. Successful lay-up will place the tanks in a safe, stable, and minimum-maintenance mode until final closure.

Thin films of Ti-Cr-Al-O are produced for use as an electrical resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O{sub 2}. Vertical resistivity values from 10{sup 4} to 10{sup 10} Ohm-cm are measured for Ti-Cr-Al-O films. The film resistivity can be design selected through control of the target composition and the deposition parameters. The Ti-Cr-Al-O thin film resistor is found to be thermally stable unlike other metal-oxide films.

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Documents completion of Milstone A.1-1, "Issue Functions and Requirements for WVDP Tank Lay-Up," in Technical Task Plan TTP RL3-WT21A - "Post-Retrival and Pre-Closure HLW Tank Lay-Up." This task is a collaborative effort among Pacific Northwest National Laboratory, Jacobs Engineering Group Inc., and West Valley Nuclear Services (WVNS). Because of the site-specific nature oft his task, the involvement of WVNS personnel is critical to the success of this task.

Adaptive mesh refinement selectively subdivides the elements of a coarse user supplied mesh to produce a fine mesh with reduced discretization error. Effective use of adaptive mesh refinement coupled with an a posteriori error estimator can produce a mesh that solves a problem to a given discretization error using far fewer elements than uniform refinement. A geometric multigrid solver uses increasingly finer discretizations of the same geometry to produce a very fast and numerically scalable solution to a set of linear equations. Adaptive mesh refinement is a natural method for creating the different meshes required by the multigrid solver. This paper describes the implementation of a scalable adaptive multigrid method on a distributed memory parallel computer. Results are presented that demonstrate the parallel performance of the methodology by solving a linear elastic rocket fuel deformation problem on an SGI Origin 3000. Two challenges must be met when implementing adaptive multigrid algorithms on massively parallel computing platforms. First, although the fine mesh for which the solution is desired may be large and scaled to the number of processors, the multigrid algorithm must also operate on much smaller fixed-size data sets on the coarse levels. Second, the mesh must be repartitioned as …

We investigate how well a coupled biosphere-atmosphere model, CCM3-IBIS, can simulate the functioning of the terrestrial biosphere and the carbon cycling through it. The simulated climate is compared to observations, while the vegetation cover and the carbon cycle are compared to an offline version of the biosphere model IBIS forced with observed climatic variables. The simulated climate presents some local biases that strongly affect the vegetation (e.g., a misrepresentation of the African monsoon). Compared to the offline model, the coupled model simulates well the globally averaged carbon fluxes and vegetation pools. The zonal mean carbon fluxes and the zonal mean seasonal cycle are also well represented except between 0{sup o} and 20{sup o}N due to the misrepresentation of the African monsoon. These results suggest that, despite regional biases in climate and ecosystem simulations, this coupled atmosphere-biosphere model can be used to explore geographic and temporal variations in the global carbon cycle.

Radiochemical diagnostics play an important role in helping scientists understand the detonation of a nuclear device. Sometimes some elements or isotopes are inserted as radiochemical detectors at various locations in the nuclear device. During the detonation of the device, these detectors are subjected for a short time to the intense flux of neutrons emitted through fission and possibly through fusion of light elements (usually deuterium and tritium). After the detonation, the radiochemical detectors and their long-lived activation products are retrieved from the area where the underground explosion took place. These radiochemical samples are analyzed to extract information about how the device operated. A large amount of such radiochemical data exist from past nuclear-device tests.

A hybrid nodal-integral/finite-analytic method (NI-FAM) is developed for time-dependent, incompressible flow in two-dimensional arbitrary geometries. In this hybrid approach, the computational domain is divided into parallelepiped and wedge-shaped space-time nodes (cells). The conventional nodal integral method (NIM) is applied to the interfaces between adjacent parallelepiped nodes (cells), while a finite analytic approach is applied to the interfaces between parallelepiped and wedge-shaped nodes (cells). In this paper, the hybrid method is formally developed and an application of the NI-FAM to fluid flow in an enclosed cavity is presented. Results are compared with those obtained using a commercial computational fluid dynamics code.

We utilize weak motion recordings to evaluate the site response at the U1A hole, Nevada Test site to determine the effect on potential ground motion at the drift of the U1A hole 962 ft deep. We estimated the site response amplification of ground motion at the surface relative to the drift with the spectral ratio method. We utilized Fourier amplitude and absolute acceleration response spectra, and confined our study to frequencies of 0.5 to 25.0 Hz (.04 to 2.0 s periods). We identified 8 earthquakes in the area that were recorded at the bottom and top of the hole that were used for spectral ratios. We calculated the average and one standard deviation of ratios from all the events. Examining the data, we found that: (1) Fourier amplitude spectral ratios provided more detailed information on the site response than the absolute acceleration response that can be directly related to the effect of large earthquakes. (2) plots of the Fourier amplitude spectra for most of the recorded earthquakes show evidence for a spectral hole in the downhole recordings. This is due to downward reflected energy from the surface. This is not evident in absolute acceleration response records. (3) Fourier amplitude spectral …

Newsletter of the Texas Department of Health discussing the news, activities, and events of the organization and other information related to health in Texas.

The Delaware Basin Drilling Surveillance Program (DBDSP) is designed to monitor drilling activities in the vicinity of the Waste Isolation Pilot Plant (WIPP). This program is based on Environmental Protection Agency (EPA) requirements. The EPA environmental standards for the management and disposal of transuranic (TRU) radioactive waste are codified in 40 CFR Part 191 (EPA 1993). Subparts B and C of the standard address the disposal of radioactive waste. The standard requires the Department of Energy (DOE) to demonstrate the expected performance of the disposal system using a probabilistic risk assessment or performance assessment (PA). This PA must show that the expected repository performance will not release radioactive material above limits set by the EPA's standard. This assessment must include the consideration of inadvertent drilling into the repository at some future time.

Determine seasonal and interannual patterns of net ecosystem CO2 flux from wet coastal and moist tussock tundra.

Charge transport in composites of inorganic nanorods and aconjugated polymer is investigated using a photovoltaic device structure.We show that the current-voltage (I-V) curves in the dark can be modelledusing the Shockley equation modified to include series and shuntresistance at low current levels, and using an improved model thatincorporates both the Shockley equation and the presence of a spacecharge limited region at high currents. Under illumination, theefficiency of photocurrent generation is found to be dependent on appliedbias. Furthermore, the photocurrent-light intensity dependence was foundto be sublinear. An analysis of the shunt resistance as a function oflight intensity suggests that the photocurrent as well as the fill factoris diminished as a result of increased photoconductivity of the activelayer at high light intensity. By studying the intensity dependence ofthe open circuit voltage for nanocrystals with different diameters andthus ! band gaps, it was inferred that Fermi-level pinning occurs at theinterface between the aluminum electrode and the nanocrystal.

A design study was undertaken to develop a ''first cut'' integrated mechanical design concept of the final focusing region for a conceptual IFE power plant that considers the major issues which must be addressed in an integrated driver and chamber system. The conceptual design in this study requires a total of 120 beamlines located in two conical arrays attached on the sides of the target chamber 180 degrees apart. Each beamline consists of four large-aperture superconducting quadrupole magnets and a dipole magnet. The major interface issues include radiation shielding and thermal insulation of the superconducting magnets; reaction of electromagnetic loads between the quadrupoles; alignment of the magnets; isolation of the vacuum regions in the target chamber from the beamline, and assembly and maintenance.

Demand response programs are often quickly and poorlycrafted in reaction to an energy crisis and disappear once the crisissubsides, ensuring that the electricity system will be unprepared whenthe next crisis hits. In this paper, we propose to eliminate theevent-driven nature of demand response programs by considering demandresponsiveness a component of the utility obligation to serve. As such,demand response can be required as a condition of service, and theoffering of demand response rates becomes a requirement of utilities asan element of customer service. Using this foundation, we explore thecosts and benefits of a smart thermostat-based demand response systemcapable of two types of programs: (1) a mandatory, system-operatorcontrolled, contingency program, and (2) a voluntary, customercontrolled, bill management program with rate-based incentives. Anydemand response program based on this system could consist of either orboth of these components. Ideally, these programs would be bundled,providing automatic load management through customer-programmed priceresponse, plus up to 10 GW of emergency load shedding capability inCalifornia. Finally, we discuss options for and barriers toimplementation of such a program in California.