Reliable quantitative prediction of contaminant transport in subsurface environments is critical to evaluating the risks associated with radionuclide migration. As part of the Underground Test Area (UGTA) project, radionuclide transport away from various underground nuclear tests conducted in the saturated zone at the Nevada Test Site (NTS) is being examined. In the near-field environment, reactive transport simulations must account for changes in water chemistry and mineralogy as a function of time and their effect on radionuclide migration. Unlike the K{sub d} approach, surface complexation (SC) reactions, in conjunction with ion exchange and precipitation, can be used to describe radionuclide reactive transport as a function of changing environmental conditions. They provide a more robust basis for describing radionuclide retardation in geochemically dynamic environments. The interaction between several radionuclides considered relevant to the UGTA project and iron oxides and calcite are examined in this report. The interaction between these same radionuclides and aluminosilicate minerals is examined in a companion report (Zavarin and Bruton, 2004). Selection criteria for radionuclides were based on abundance, half-life, toxicity to human and environmental health, and potential mobility at NTS (Tompson et al., 1999). Both iron oxide and calcite minerals are known to be present at NTS in …

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OpenMP is a widely adopted standard for threading directives across compiler implementations. The standard is very successful since it provides application writers with a simple, portable programming model for introducing shared memory parallelism into their codes. However, the standards do not address key issues for supporting that programming model in development tools such as debuggers. In this paper, we present DMPL, an OpenMP debugger interface that can be implemented as a dynamically loaded library. DMPL is currently being considered by the OpenMP Tools Committee as a mechanism to bridge the development tool gap in the OpenMP standard.

In many applications of optical systems, the observed field in the pupil plane has a non-uniform phase component. This deviation of the phase of the field from uniform is called a phase aberration. In imaging systems this aberration will degrade the quality of the images. In the case of a large astronomical telescope, random fluctuations in the atmosphere lead to significant distortion. These time-varying distortions can be corrected using an Adaptive Optics (AO) system, which is a real-time control system composed of optical, mechanical and computational parts. Adaptive optics is also applicable to problems in vision science, laser propagation and communication. For a high-level overview, consult this web site. For an in-depth treatment of the astronomical case, consult these books.

Synthetic ion beams with instantaneous and temporal characteristics appropriate to thermal ionization mass spectrometry (TIMS) were mathematically generated and analyzed to determine the effects of using a mixed {sup 233}U-{sup 236}U spike (double-spike) in the analysis of uranium isotopes. The instantaneous beam characteristics are the intensities (e.g., counts per second) modeled with a Poisson distribution plus a component of random noise that simulates the detection processes. Several beam intensity and mass fractionation vs. time functions were modeled to simulate a range of sample sizes and the commonly employed methods of data collection. These beam profiles were also generated with different noise levels, and signal-to-noise vs. analytical precision diagrams are presented. Modeling focused on natural uranium, where {sup 238}U/{sup 235}U = 137.88, and on the ability of a given method to determine precisely and accurately small variations in this ratio. Practical limits on precision were determined to be 20-30 ppm, which is consistent with precision seen for other elements by state-of-the-art TIMS. The TIMS total evaporation method was compared directly with the double-spike method. While similar analytical precisions are obtained with either method, the double-spike method of correcting for analytical bias gives more accurate results. The results of a total evaporation …

The purpose of this project is to develop a robust scientific and technological framework for the design of high-strength and -ductility nanocrystalline materials for applications of technical importance to the Laboratory. The project couples theory and experiments with an emphasis on materials of macroscopic dimensions (mm to cm) that are composed of nanoscale (<100 nm) grains. There are four major tasks: (1) synthesize nanocrystalline materials with grain size in the 5- to 100-nm range; (2) conduct experimental studies to probe mechanisms of mechanical deformation and failure; (3) use large-scale simulation modeling technologies to provide insight to deformation mechanisms that may not be observable experimentally; and (4) check the results obtained from modeling, comparing experimental observations with results obtained from atomistic and dislocation-based simulations. This project supports efforts within the Stockpile Stewardship Program (SSP) to understand and predict properties of metals such as strength and ductility.

In this project I apply the concepts and techniques learned in Applied Computational Harmonic Analysis (ACHA) to my research. I am currently developing fast wave-front reconstruction techniques for high-order Adaptive Optics systems. The fast reconstruction technique which we plan on using is based on the DFT. Reconstruction and optional filtering occur in the frequency domain. This is a significantly different approach than current methods of wave-front reconstruction, which use a matrix multiply to do the reconstruction. The latest advances in these methods use modal control, which effectively seeks to control individual modes (or basis functions) as opposed to the signal on a point-by-point basis. These techniques can be adapted to incorporate statistical knowledge. My research task to is figure out how to do such a modal approach with my fast reconstructor. This project report is divided into several sections. In the first section I summarize Adaptive Optics concepts and discuss the problem of wave-front reconstruction in greater detail. Following this is a brief summary of the most applicable concepts and techniques from ACHA that will be applied to the problem. The application of these techniques is then discussed.

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The Stochastic Engine (SE) is a data driven computer simulation tool for predicting the characteristics of complex systems. The SE integrates accurate simulators with the Monte Carlo Markov Chain (MCMC) approach (a stochastic inverse technique) to identify alternative models that are consistent with available data and ranks these alternatives according to their probabilities. Implementation of the SE is currently cumbersome owing to the need to customize the pre-processing and processing steps that are required for a specific application. This project widens the applicability of the Stochastic Engine by generalizing some aspects of the method (i.e. model-to-data transformation types, configuration, model representation). We have generalized several of the transformations that are necessary to match the observations to proposed models. These transformations are sufficiently general not to pertain to any single application. This approach provides a framework that increases the efficiency of the SE implementation. The overall goal is to reduce response time and make the approach as ''plug-and-play'' as possible, and will result in the rapid accumulation of new data types for a host of both earth science and non-earth science problems. When adapting the SE approach to a specific application, there are various pre-processing and processing steps that are typically …

A Working Group Meeting on Heavy Vehicle Aerodynamic Drag was held in Portland, Oregon on July 1, 2004. The purpose of the meeting was to provide a summary of achievements, discuss pressing issues, present a general overview of future plans, and to provide a forum for dialogue with the Department of Energy (DOE) and industry representatives. The meeting was held in Portland, because the DOE Aero Team participated in an exclusive session on Heavy Truck Vehicle Aerodynamic Drag at the 34th AIAA Fluid Dynamics Conference and Exhibit in Portland on the morning of July 1st, just preceding our Working Group meeting. Even though the paper session was on the last day of the Conference, the Team presented to a full room of interested attendees.

An experimental procedure is reported to perform shear tests on specimens held under moderately high hydrostatic pressures (on the order of 10 GPa). The mechanical behavior of materials subjected to such pressures, varies substantially from that observed at atmospheric pressure or even pressures typically attained during industrial processing. These differences must be incorporated into models such as the Steinberg-Guinan hardening model or discrete dislocation dynamics simulations. The goal of the proposed research is to develop and implement testing procedures that experimentally determine pressure-dependent dislocation mobilities in oriented single crystals of the BCC transition metals. These experiments will provide calibration data for models of materials subjected to extreme pressures and will assist in model validation. This paper reports the development of the experimental procedures. A thin foil of polycrystalline Ta was used to perform the initial experiments under hydrostatic pressures ranging from 2.1 to 4.2 GPa. Both yielding and hardening behavior are observed to be sensitive to the imposed pressure.

We develop a model-based processor (MBP) for a micro-cantilever array sensor to detect target species in solution. After discussing the generalized framework for this problem, we develop the specific model used in this study. We perform a proof-of-concept experiment, fit the model parameters to the measured data and use them to develop a Gauss-Markov simulation. We then investigate two cases of interest: (1) averaged deflection data, and (2) multi-channel data. In both cases the evaluation proceeds by first performing a model-based parameter estimation to extract the model parameters, next performing a Gauss-Markov simulation, designing the optimal MBP and finally applying it to measured experimental data. The simulation is used to evaluate the performance of the MBP in the multi-channel case and compare it to a ''smoother'' (''averager'') typically used in this application. It was shown that the MBP not only provides a significant gain ({approx} 80dB) in signal-to-noise ratio (SNR), but also consistently outperforms the smoother by 40-60 dB. Finally, we apply the processor to the smoothed experimental data and demonstrate its capability for chemical detection. The MBP performs quite well, though it includes a correctable systematic bias error. The project's primary accomplishment was the successful application of model-based processing …

In the coherent X-ray diffraction imaging experiments, samples will be injected or placed in the beam and a two-dimensional diffraction pattern will be collected for a single pulse. This is repeated for a large number of pulses, with the data being read out of the detector each pulse, and stored if the data meets a requirement of enough total recorded counts. There must be sufficient pixels in the detector to over-sample the diffraction pattern, which depends on the sample size and desired resolution, as described below. The scattering from the sample covers a large dynamic range: it is strong very close to the central core and at high angles there will be much less than one photon per pixel. Since the technique relies upon classifying and averaging a large number of patterns, the read noise must be considerably less than the photon count per pixel averaged over these patterns. Estimates of the noise level and dynamic range are given below, after first listing the requirements of pixel count and sampling.

The two year LDRD-ER-089 project Electromagnetic Imaging of CO{sub 2} Sequestration at an Enhanced-Oil-Recovery Site used a dual track approach to imaging and interpreting the effectiveness and migration of CO2 injection at an enhanced oil recovery site. Both field data and laboratory data were used together to aid in the interpretation and understanding of CO{sub 2} flow in a heavily fracture enhanced oil recovery site. In particular, project highlights include; {lg_bullet} The development of a low-noise digital field system to measure the EM induction response to CO{sub 2} in a variety of field conditions. Central to this system is a low-noise induction receiver antenna that can measure the low-energy response of the CO{sub 2}. This system has consistently measured a shallow pseudo-miscible CO{sub 2} flood at source frequencies between 2.0 kHz and 10 kHz. In addition, the existing and added oil and brine in the formation have also been characterized. {lg_bullet} Comparisons of cross-well images with induction logs acquired before drilling suggest the EM induction resolution for CO2 imaging is equivalent with applications to waterflood imaging completed at LLNL. {lg_bullet} The development and use of laboratory equipment to conduct fluid and gas time-lapsed injection studies of core samples using fluids …

We have developed new techniques based on atomic force microscopy (AFM) to image, and to quantify the strength of, specific receptor sites on the membrane of a living cell. AFM has developed rapidly during the past decade, providing nanometer scale resolution in the imaging of biological materials ranging in size from single molecules to intact cells. By monitoring the cantilever deflection during approach-retraction cycles (i.e. force-volume curves), the unbinding forces have been determined for various ligand-receptor pairs. It is now possible to use a single receptor molecule bound to the tip of an AFM cantilever to map the locations of ligands bound on solid surfaces, opening the door for new ''recognition mapping'' methods. The goal of our project was to develop recognition mapping for living cells and cell membranes, a major step forward.

An efficient inversion algorithm has been developed forthree-dimensional (3D) interpretations for single-hole electromagnetic(EM) logging data based on a modified extended Born approximation (MEBA)scheme. The single-hole data was collected at an oil field undergoing CO2injection in southern California using a tool, Geo-BILT, developed byElectromagnetic Instruments, Inc (EMI). The tool is equipped with amulti-component source, and an array of multi-component receivers atdifferent separations. The inversion result provides a reasonableelectrical conductivity image to a distance of 10 m from the well, andillustrates several zones with lateral conductivity variations that couldnot be resolved with traditional induction logging tools. The computercost of the inversion processes can be further reduced using a trivialmulti-grid methodology.

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The critical height for DNAPL entry into a partially watersaturated, dead-end fracture is derived and compared to laboratoryobservations. Experiments conducted in an analog, parallel-plate fracturedemonstrate that DNAPL accumulates above the water until the height ofthe DNAPL overcomes the sum of the capillary forces at the DNAPL-airinterface and at the DNAPL-water interface. These experiments also showthat DNAPL preferentially enters the water at locations where DNAPL haspreviously entered, and the entry heights for these subsequent entriesare lower than the heights measured for the initial invasion. The wettingcontact angle at the DNAPL-water interface becomes larger at thelocations where the DNAPL has already entered the water because ofresidual DNAPL on the fracture walls, which results in lowering thecritical entry height at those locations. The experiments alsodemonstrate that a DNAPL lens can remain nearly immobile above the waterfor a period of time before eventually redistributing itself and enteringthe water.

The current plans for the Yucca Mountain (YM) repository project (YMP) use steel structures to stabilize the disposal drifts and connecting tunnels that are collectively over 100 kilometers in length. The potential exist to reduce the underground construction cost by 100s of millions of dollars and improve the repository's performance. These economic and engineering goals can be achieved by using the appropriate cementitious materials to build out these tunnels. This report describes the required properties of YM compatible cements and reviews the literature that proves the efficacy of this approach. This report also describes a comprehensive program to develop and test materials for a suite of underground construction technologies.

The design and analysis of measurements performed with organic scintillators rely on the use of Monte Carlo codes to simulate the interaction of neutrons and photons, originating from fission and other reactions, with the materials present in the system and the radiation detectors. MCNP-PoliMi is a modification of the MCNP-4c code that models the physics of secondary particle emission from fission and other processes realistically. This characteristic allows for the simulation of the higher moments of the distribution of the number of neutrons and photons in a multiplying system. The present report describes the recent additions to the MCNP-PoliMi post-processing code. These include the simulation of detector dead time, multiplicity, and third order statistics.

This report summarizes the accomplishments toward project goals during the first twelve months of the project to assess the properties and performance of coal based products. These products are in the gasoline, diesel and fuel oil range and result from coal based jet fuel production from an Air Force funded program. Specific areas of progress include generation of coal based material that has been fractionated into the desired refinery cuts, acquisition and installation of a research gasoline engine, and modification of diesel engines for use in evaluating diesel produced in the project. The desulfurization of sulfur containing components of coal and petroleum is being studied so that effective conversion of blended coal and petroleum streams can be efficiently converted to useful refinery products. Equipment is now in place to begin fuel oil evaluations to assess the quality of coal based fuel oil. Coal samples have procured and are being assessed for cleaning prior to use in coking studies.

An analysis of the links between high impact technologies and publicly funded scientific research.

This report describes FY 2003 technical studies conducted by the Chemical Biology and Nuclear Science Division (CBND) at Lawrence Livermore National Laboratory (LLNL) in support of the Hydrologic Resources Management Program (HRMP) and the Underground Test Area (UGTA) Project. These programs are administered by the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) through the Defense Programs and Environmental Restoration Divisions, respectively. HRMP-sponsored work is directed toward the responsible management of the natural resources at the Nevada Test Site (NTS), enabling its continued use as a staging area for strategic operations in support of national security. UGTA-funded work emphasizes the development of an integrated set of groundwater flow and contaminant transport models to predict the extent of radionuclide migration from underground nuclear testing areas at the NTS. The present report is organized on a topical basis and contains five chapters that reflect the range of technical work performed by LLNL-CBND during FY 2003. Although we have emphasized investigations that were led by CBND, we also participated in a variety of collaborative studies with other UGTA and HRMP contract organizations including the Energy and Environment Directorate at LLNL (LLNL-E&E), Los Alamos National Laboratory (LANL), the Desert Research …

Core Leak-off tests are commonly used to ascertain the ability of a drilling fluid to seal permeable rock under downhole conditions. Unfortunately, these tests are expensive and require a long time to set up. To monitor fluid invasion trends and to evaluate potential treatments for reducing fluid invasion on location, a simpler screening test is highly desirable. The Capillary Suction Time (CST) Test has been used since the 1970's as a fast, yet reliable, method for characterizing fluid filterability and the condition of colloidal materials in water treatment facilities and drilling fluids. For the latter, it has usually been applied to determine the state of flocculation of clay-bearing fluids and to screen potential shale inhibitors. In this work, the CST method was evaluated as a screening tool for predicting relative invasion rates of drilling fluids in permeable cores. However, the drilling fluids examined--DRILPLEX, FLOPRO, and APHRON ICS--are all designed to generate low fluid loss and give CST values that are so high that fluid invasion comes to be dominated by experimental artifacts, such as fluid evaporation. As described in this work, the CST procedure was modified so as to minimize such artifacts and permit differentiation of the fluids under investigation.