April report of the U.S. Congressional Oversight Panel describing their activities and findings regarding the federal government's current strategy in mitigating the effects of the 2007-2008 financial crisis through the Troubled Asset Relief Fund (TARP).

May report of the U.S. Congressional Oversight Panel describing their activities and findings regarding consumer lending to small businesses and households through the Term Asset-Backed Securities Loan Facility program (TALF).

The Accelerated Strategic Computing Initiative (ASCI) Problem Solving Environment (PSE) consists of the tools and libraries needed for the development of ASCI simulation codes on ASCI machines. The recently completed ASCI PSE Milepost demonstrated that this software environment is available and functional at the scale used for application mileposts on ASCI White. As part of the PSE Milepost, we performed extensive performance testing of several critical run-time based systems. In this paper, we present microbenchmark results that compare the MPI [5], Pthreads and OpenMP [7, 8] implementations on ASCI White and ASCI Blue Pacific. Our results demonstrate that these run-time systems on White have improved sufficiently to accommodate the machine's approximately four-fold increase in processing capability over Blue Pacific.

We used synthetic aperture radar interferograms to image ground subsidence that occurred over the Dixie Valley geothermal field during different time intervals between 1992 and 1997. Linear elastic inversion of the subsidence that occurred between April, 1996 and March, 1997 revealed that the dominant sources of deformation during this time period were large changes in fluid volumes at shallow depths within the valley fill above the reservoir. The distributions of subsidence and subsurface volume change support a model in which reduction in pressure and volume of hot water discharging into the valley fill from localized upflow along the Stillwater range frontal fault is caused by drawdown within the upflow zone resulting from geothermal production. Our results also suggest that an additional source of fluid volume reduction in the shallow valley fill might be similar drawdown within piedmont fault zones. Shallow groundwater flow in the vicinity of the field appears to be controlled on the NW by a mapped fault and to the SW by a lineament of as yet unknown origin.

The power of a quantum computer (QC) relies on the fundamental concept of the superposition in quantum mechanics and thus allowing an inherent large-scale parallelization of computation. In a QC, binary information embodied in a quantum system, such as spin degrees of freedom of a spin-1/2 particle forms the qubits (quantum mechanical bits), over which appropriate logical gates perform the computation. In classical computers, the basic unit of information is the bit, which can take a value of either 0 or 1. Bits are connected together by logic gates to form logic circuits to implement complex logical operations. The expansion of modern computers has been driven by the developments of faster, smaller and cheaper logic gates. As the size of the logic gates become smaller toward the level of atomic dimensions, the performance of such a system is no longer considered classical but is rather governed by quantum mechanics. Quantum computers offer the potentially superior prospect of solving computational problems that are intractable to classical computers such as efficient database searches and cryptography. A variety of algorithms have been developed recently, most notably Shor's algorithm for factorizing long numbers into prime factors in polynomial time and Grover's quantum search algorithm. …

The Inner and Outer modules of the Central Solenoid Model Coil (CSMC) were built by US and Japanese home teams in collaboration with European and Russian teams to demonstrate the feasibility of a superconducting Central Solenoid for ITER and other large tokamak reactors. The CSMC mass is about 120 t, OD is about 3.6 m and the stored energy is 640 MJ at 46 kA and peak field of 13 T. Testing of the CSMC and the CS Insert took place at Japan Atomic Energy Research Institute (JAERI) from mid March until mid August 2000. This paper presents the main results of the tests performed.

This letter report is a supplement to the letter reports submitted previously under ECRs No. 2002-600-012 (Borrow Area C) and No. 2002-600-012a (CWC expansion). This letter report covers all areas that may be subject to surface disturbance under Alternative Groups A, B, C, D1, D2, D3, E1, E2, E3, and the No Action Alternative of the Hanford Solid Waste Environmental Impact Statement (HSW EIS), except for the following Low-Level Burial Grounds (LLBGs). The LLBGs proposed for use in the HSW EIS that are not subject of this letter report (218-W-3A, 218-W-3AE, 218-W 4B, 218-W-5, the developed portion of 218-W-4C, and the eastern half [except the northeastern corner] of 218-W-6 in the 200 West Area; and 218-E-10 and 218-E-12B in the 200 East Area) are surveyed annually. Annual letter reports concerning these are currently sent to Mr. Brett M. Barnes of Fluor Hanford, Inc. For the areas of surface disturbance described herein we provide a summary of field survey methods, survey results, and considerations and recommendations based on these results.

Estimating unknown system configurations/parameters by combining system knowledge gained from a computer simulation model on one hand and from observed data on the other hand is challenging. An example of such inverse problem is detecting and localizing potential flaws or changes in a structure by using a finite-element model and measured vibration/displacement data. We propose a probabilistic approach based on Bayesian methodology. This approach does not only yield a single best-guess solution, but a posterior probability distribution over the parameter space. In addition, the Bayesian approach provides a natural framework to accommodate prior knowledge. A Markov chain Monte Carlo (MCMC) procedure is proposed to generate samples from the posterior distribution (an ensemble of likely system configurations given the data). The MCMC procedure proposed explores the parameter space at different resolutions (scales), resulting in a more robust and efficient procedure. The large-scale exploration steps are carried out using coarser-resolution finite-element models, yielding a considerable decrease in computational time, which can be a crucial for large finite-element models. An application is given using synthetic displacement data from a simple cantilever beam with MCMC exploration carried out at three different resolutions.

This LDRD project consisted of the development, testing, and prototype application of a new capability to couple atmospheric models of different spatial and temporal scales with a state-of-the-science vegetation-fuel combustion model and a GIs-based analysis system. The research addressed the complex, multi-scale interactions of atmospheric processes, combustion, and vegetative fuel conditions, using a suite of models to simulate their impact on wildfire behavior in areas of complex terrain. During the course of the project, we made substantial progress toward the implementation of a world-class modeling system that could be used as a tool for wildfire risk assessment, wildfire consequence analysis, wildfire suppression planning, fuels management, firefighter training, and public fire-safety education. With one additional year of funding we would have been able conduct combined modeling and field experiments to evaluate the models capability to predict the behavior of prescribed burns before they are ignited. Because of its investment in this LDRD project, LLNL is very close to having a new core capability--likely the world's most generally applicable, most scientifically sound, and most respected wildfire simulation system.

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Magnetohydrodynamics (MHD) turbulence theory, often employed satisfactorily in astrophysical applications, has often focused on parameter ranges that imply nearly equal values of kinetic and magnetic energies and length scales. However, MHD flow may have disparity magnetic Prandtl number, dissimilar kinetic and magnetic Reynolds number, different kinetic and magnetic outer length scales, and strong anisotropy. Here a phenomenology for such ''non-equipartitioned'' MHD flow is discussed. Two conditions are proposed for a MHD flow to transition to strong turbulent flow, extensions of (1) Taylor's constant flux in an inertial range, and (2) Kolmogorov's scale separation between the large and small scale boundaries of an inertial range. For this analysis, the detailed information on turbulence structure is not needed. These two conditions for MHD transition are expected to provide consistent predictions and should be applicable to anisotropic MHD flows, after the length scales are replaced by their corresponding perpendicular components. Second, it is stressed that the dynamics and anisotropy of MHD fluctuations is controlled by the relative strength between the straining effects between eddies of similar size and the sweeping action by the large-eddies, or propagation effect of the large-scale magnetic fields, on the small scales, and analysis of this balance in principle …

We have developed a conceptual design for a 50 TW/20 J short-pulse laser for performing high-energy-density plasma physics experiments at the Nevada Terawatt Facility of the University of Nevada, Reno. The purpose of the laser is to develop proton and x-ray radiography techniques, to use these techniques to study z-pinch plasmas, and to study deposition of intense laser energy into both magnetized and unmagnetized plasmas. Our design uses a commercial diode-pumped Nd:glass oscillator to generate 3-nJ. 200-fs mode-locked pulses at 1059 m. An all-reflective grating stretcher increases pulse duration to 1.1 ns. A two-stage chirped-pulse optical parametric amplifier (OPCPA) using BBO crystals boosts pulse energy to 12 mJ. A chain using mixed silicate-phosphate Nd:glass increases pulse energy to 85 J while narrowing bandwidth to 7.4 nm (FWHM). About 50 J is split off to the laser target chamber to generate plasma while the remaining energy is directed to a roof-mirror pulse compressor, where two 21 cm x 42 cm gold gratings recompress pulses to {approx}350 fs. A 30-cm-focal-length off-axis parabolic reflector (OAP) focuses {approx}20 J onto target, producing an irradiance of 10{sup 19} W/cm{sup 2} in a 10-{micro}m-diameter spot. This paper describes planned plasma experiments, system performance requirements, the laser …

Overview. This document and the accompanying manuscripts summarize the technical accomplishments of our one-year LDRD-ER effort, a project that has since been incorporated into a larger LDRD-SI for FY05. The objective of this effort was to develop a predictive synthetic capability for the preparation of materials with cellular architectures (sub-micron pore or cell sizes and relative densities less than 10% of full density) not attainable by conventional methods. The ability to reliably prepare these nanocellular materials and control their bulk physical properties (e.g. mechanical strength) would be a considerable advance in the areas of porous materials and its impact would cut across many existing LLNL investments. One significant area related to the Laboratory mission that would benefit is the design of new materials for high energy density physics (HEDP) targets. Current synthetic techniques do not allow for the preparation of foams that meet all of the current and projected compositional and mechanical requirements of these experiments. This project focused on two main types of materials: inorganic sol-gel materials and nanocellular metal foams. The following sections describe the project goals for these two types of materials as well as the progress made towards these goals in FY04. These sections also provide …

Current designs for inertial confinement fusion capsules for the National Ignition Facility (NIF) consist of a solid deuterium-tritium (D-T) fuel layer inside of a copper doped beryllium capsule. Phase contrast enhanced x-ray imaging is shown to render the D-T layer visible inside the Be(Cu) capsule. Phase contrast imaging is experimentally demonstrated for several surrogate capsules and validates computational models. Polyimide and low density divinyl benzene foam capsules were imaged at the Advanced Photon Source synchrotron. The surrogates demonstrate that phase contrast enhanced imaging provides a method to characterize surfaces when absorption imaging cannot be used. Our computational models demonstrate that a rough surface can be accurately reproduced in phase contrast enhanced x-ray images.

General frameworks for distributed computing are slowly evolving out of Grid, Peer Architecture, and Web Services. The following results from a summer long survey into distributing computing practices have revealed three things. One, that Legion and Cactus-G have achieved the most in terms of providing an all-purpose application environment. Two, that extending a local programming environment to operate in a highly distributed fashion can be facilitated with toolkits like Globus. Three, that building a new system from the ground up could be realized, in part, by using some of the following components; an Object Oriented Database, Tapestry, JXTA, BOINC, Globus, component architecture technology, XML and related libraries, Condor-G, Proteus, and ParMETIS.

Perturbations on an interface driven by a strong blast wave grow in time due to a combination of Rayleigh-Taylor, Richtmyer-Meshkov, and decompression effects. In this paper, we present the first results from a computational study of such a system under drive conditions to be attainable on the National Ignition Facility. Using the multiphysics, AMR, higher order Godunov Eulerian hydrocode, Raptor, we consider the late nonlinear instability evolution for multiple amplitude and phase realizations of a variety of multimode spectral types. We show that compressibility effects preclude the emergence of a regime of self-similar instability growth independent of the initial conditions by allowing for memory of the initial conditions to be retained in the mix-width at all times. The loss of transverse spectral information is demonstrated, however, along with the existence of a quasi-self-similar regime over short time intervals. The initial conditions are shown to have a strong affect on the time to transition to the quasi-self-similar regime.

Phase stability and aging mechanisms in a water-quenched (WQ) U-6wt% Nb (U-14at% Nb) alloy artificially aged at 200 C and naturally aged at ambient temperature for 15 years have been investigated and studied using Vickers-hardness measurement, X-ray diffraction (XRD) analysis, and transmission electron microscopy (TEM) techniques. Age hardening/softening phenomenon is recorded from the artificially aged samples based upon the microhardness measurement. The age hardening can be readily rationalized by the occurrence of fine-scaled Nb segregation, or spinodal decomposition, within the {alpha}'' domains, which results in the formation of a modulated structure containing nano-scaled Nb-rich and Nb-lean domains. Prolonged aging leads to age softening of the alloy by coarsening of the modulated structure. Chemical ordering, or disorder-order phase transformation, is found within the naturally aged alloy according to TEM observations of antiphase domain boundaries (APBs) and superlattice diffraction patterns. A possible superlattice structure for the ordered {alpha}'' phase observed in the naturally aged sample and underlying low-temperature aging mechanisms are proposed.

Equations for modeling surface chemical kinetics by the interaction of gaseous and surface species are presented. The formulation is embedded in a finite element heat transfer code and an ordinary differential equation package is used to solve the surface system of chemical kinetic equations for each iteration within the heat transfer solver. The method is applied to a flow which includes methane and methanol in a microreactor on a chip. A simpler more conventional method, a plug flow reactor model, is then applied to a similar problem. Initial results for steam reforming of methanol are given.

This document reports the results of the 25 Can Verification Run. The 25 Can Verification Run was performed as outlined in Section 1.d of SRS Acceptance Criteria (Reference 1). The run was performed over the period of February 16 to the 28, 2001. Each of these cans was welded with a dummy Inner Can containing about 5 kg of surrogate material. The cans were then analyzed using radiography and metallography of samples taken at four locations of the weld. The radiographs were examined for porosity. The micrographs of the metallurgical samples were examined for porosity, cracks, and lack of fusion. The results were reviewed by Derrill Rikard (a level 3 inspector at LLNL) and by Ken Durland (a level 3 inspector from WSRC). These reviews did not find anything of concern. Therefore we are submitting these results to SRS for concurrence.

This ICN documents the installation of three additional downgradient monitoring wells and one additional upgradient well. It updates the monitoring network and the stratigraphy of the aquifer.

The effects of microbiological activities on the surface composition of Alloy 22 was investigated. Prior studies suggesting microbially-generated selective dissolution of chromium from Alloy 22 were based solely on analyzing solubilized Alloy 22 elements. These and other investigations point to the insufficiencies of analyzing solubilized (or solubilized and reprecipitated) alloying elements to discern between homogeneous/stoichiometric dissolution and selective/non-stoichiometric dissolution of alloying elements. Therefore, an approach using X-ray Photoelectron Spectroscopy (XPS) to interrogate the surface layers of treated Alloy 22 specimens was taken to resolve this issue. Sputtering into the surface of the samples, coupled with XPS analysis at given intervals, allowed a high resolution quantitative elemental evaluation of the alloy as a function of depth. Biotically-incubated Alloy 22 show a region that could be depleted of chromium. Surfacial XPS analysis of these same coupons did not detect the presence of re-precipitated Alloy 22 component elements, also supporting the possible occurrence of non-stoichiometric dissolution. Thus, these preliminary data do not exclude the possibility of selective dissolution. It also appears that this experimental approach shows promise to unequivocally resolve this issue. Further tests using smoother-surface, more highly polished coupons should allow for better resolution between surface layers to permit a decisive determination …

The effect of preparation conditions on the structural and optical properties of silicon nanoparticles is investigated. Nanoscale reconstructions, unique to curved nanosurfaces, are presented for silicon nanocrystals and shown to have lower energy and larger optical gaps than bulk-derived structures. We find that high-temperature synthesis processes can produce metastable non-crystalline nanostructures with different core structures than bulk-derived crystalline clusters. The type of core structure that forms from a given synthesis process may depend on the passivation mechanism and time scale. The effect of oxygen on the optical of different types of silicon structures is calculated. In contrast to the behavior of bulk-like nanostructures, for non-crystalline and reconstructed crystalline structures surface oxygen atoms do not decrease the gap. In some cases, the presence of oxygen atoms at the nanocluster surface can significantly increase the optical absorption gap, due to decreased angular distortion of the silicon bonds. The relationship between strain and the optical gap in silicon nanoclusters is discussed.

Three sets of LX-04 samples of 0.18 and 0.49 mm nominal thicknesses were all dynamically loaded by Sandia's Z-accelerator with a ramp compression wave with a 200 ns rise time and about 150 kb peak stress. The LX-04/lithium fluoride samples interface velocities were measured using VISAR's. Comparisons of experimental and computational results are given. Compression and release isentropes both show some reaction and kinetic behavior of the LX-04. Experiments were also performed on fine-grained TATB. Future experiments on single crystals of HMX that are designed to measure the phase transition at high pressures is discussed.

In looking at simulations for the x-ray microscope the question ''Is it necessary to use the multislice method to adequately model the transmission of x-rays through the target?'' has been raised. Another question that has been raised is ''Is it necessary to include diffraction effects in our simulations?'' The purpose of this report is to lay these questions to rest. The short answer to both of these questions is ''No''. The multislice method (also known as the beam propagation method (BPM)) is used to solve the paraxial wave equation. The paraxial wave equation is what the Helmholtz equation reduces to in the limit of small index of refraction deviations and small angular deviations. It lies in the middle ground between full wave simulation and ray tracing (a short wavelength limit). The BPM takes a region and cuts it into strips. The method then propagates a wavefront through the region one strip at a time. For each strip, the method first propagates the wavefront the width of the strip as if through free space (diffraction step), then the method applies a phase correction based on the index of refraction distribution in the strip (refraction step). In this way the method marches …