Big computers are icons: symbols of the culture, and of the larger computing infrastructure that exists at Lawrence Livermore. Through the collective effort of Laboratory personnel, they enable scientific discovery and engineering development on an unprecedented scale. For more than three decades, the Computation Directorate has supplied the big computers that enable the science necessary for Laboratory missions and programs. Livermore supercomputing is uniquely mission driven. The high-fidelity weapon simulation capabilities essential to the Stockpile Stewardship Program compel major advances in weapons codes and science, compute power, and computational infrastructure. Computation's activities align with this vital mission of the Department of Energy. Increasingly, non-weapons Laboratory programs also rely on computer simulation. World-class achievements have been accomplished by LLNL specialists working in multi-disciplinary research and development teams. In these teams, Computation personnel employ a wide array of skills, from desktop support expertise, to complex applications development, to advanced research. Computation's skilled professionals make the Directorate the success that it has become. These individuals know the importance of the work they do and the many ways it contributes to Laboratory missions. They make appropriate and timely decisions that move the entire organization forward. They make Computation a leader in helping LLNL achieve …

This report describes the interpolation package in the Livermore Equation of State (LEOS) system. It is an updated and expanded version of report [1], which described the status of the package as of May 1998, and of [2], which described its status as of the August 2001 release of the LEOS access library, and of [3], which described its status as of library version 7.02, released April 2002. This corresponds to library version 7.11, released March 2003. The main change since [3] has been the addition of the monotone bicubic Hermite (bimond) interpolation method. Throughout this report we assume that data has been given for some function f({rho},T) on a rectangular mesh {rho} = {rho}{sub 0}, {rho}{sub 1}, ..., {rho}{sub nr-1}; T = T{sub 0}, T{sub 1}, ..., T{sub nt-1}. Subscripting is from zero to be consistent with the C code. (Although we use this notation throughout, there is nothing in the package that assumes that the independent variables are actually density and temperature.) The data values are f{sub ij} = f({rho}{sub j},T{sub i}). (This subscript order is historical and reflects the notation used in the program.) There are nr x nt data values, (nr-1) x (nt-1) mesh rectangles (boxes). …

A four-cylinder 1.9 Volkswagen TDI Engine has been converted to run in Homogeneous Charge Compression Ignition (HCCI) mode. The stock configuration is a turbocharged direct injection Diesel engine. The combustion chamber has been modified by discarding the in-cylinder Diesel fuel injectors and replacing them with blank inserts (which contain pressure transducers). The stock pistons contain a reentrant bowl and have been retained for the tests reported here. The intake and exhaust manifolds have also been retained, but the turbocharger has been removed. A heater has been installed upstream of the intake manifold and fuel is added just downstream of this heater. The performance of this engine in naturally aspirated HCCI operation, subject to variable intake temperature and fuel flow rate, has been studied. The engine has been run with propane fuel at a constant speed of 1800 rpm. This work is intended to characterize the HCCI operation of the engine in this configuration that has been minimally modified from the base Diesel engine. The performance (BMEP, IMEP, efficiency, etc) and emissions (THC, CO, NOx) of the engine are presented, as are combustion process results based on heat release analysis of the pressure traces from each cylinder.

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This study investigates the inspection of a particular layer of a multi-layer structure using ultrasonic guided waves. Techniques based on Lamb waves have been developed for the inspection of plate structures and are well understood. Guided waves also exist in multi-layered plates as well. Energy distributions vary across the thickness of a multi-layer structure depending on the mode and frequency. Hence, a potential way to inspect the bottom layer of a structure is to find modes with sufficient energy in the bottom layer.

It is necessary to place a barrier foil in front of the X-ray converter target to prevent the backstreaming ions. This research note presents the simulations of foil heating using the latest EOS tables. LASNEX simulations are carried out using both DARHT-II and ETA-II beam parameters. Results for all the foils studied here, using the DARHT-II beam parameters, show that the integrated line density along the axis at the end of the 4th pulse remains essentially unchanged even if the foils are heated by beams with relatively small beam spot sizes. The temperature can reach up to 3000 C on graphite foil but can only reach several hundred degree Celsius on Mylar foil. Simulations also show that ETA-II beam can create a ''burn-through'' hole on all the foils except graphite and diamond foils, which may require pre-heat. The threshold beam spot size required for hole formation will be compared with LASNEX simulation for the purpose of code verification.

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The discovery that ultra-intense laser pulses (I > 10{sup 18} W/cm{sup 2}) can produce short pulse, high energy proton beams has renewed interest in the fundamental mechanisms that govern particle acceleration from laser-solid interactions. Experiments have shown that protons present as hydrocarbon contaminants on laser targets can be accelerated up to energies > 50 MeV. Different theoretical models that explain the observed results have been proposed. One model describes a front-surface acceleration mechanism based on the ponderomotive potential of the laser pulse. At high intensities (I > 10{sup 18} W/cm{sup 2}), the quiver energy of an electron oscillating in the electric field of the laser pulse exceeds the electron rest mass, requiring the consideration of relativistic effects. The relativistically correct ponderomotive potential is given by U{sub p} = ([1 + I{lambda}{sup 2}/1.3 x 10{sup 18}]{sup 1/2} - 1) m{sub o}c{sup 2}, where I{lambda}{sup 2} is the irradiance in W{micro}m{sup 2}/cm{sup 2} and m{sub o}c{sup 2} is the electron rest mass.At laser irradiance of I{lambda}{sup 2} {approx} 10{sup 20} W{micro}m{sup 2}/cm{sup 2}, the ponderomotive potential can be of order several MeV. A few recent experiments--discussed in Chapter 3 of this thesis--consider this ponderomotive potential sufficiently strong to accelerate protons from the …

I review recent progress in lattice QCD at finite temperature. Results on the transition temperature will be summarized. Recent progress in understanding in-medium modifications of interquark forces and quarkonia spectral functions at finite temperatures is discussed.

People who know their way around metalworking are no doubt familiar with peening--using a ball-peen hammer to pound a piece of metal into shape and strengthen it against fatigue failure. For the past 50 years, an industrialized equivalent has been shot peening, in which metal or ceramic beads as large as marbles or as small as salt and pepper grains pneumatically bombard a metal surface. Laser peening, a process based on a superior laser technology developed at Lawrence Livermore, replaces the hammer blows and streams of beads with short blasts of laser light. The end result is a piece of metal with significantly improved performance. Lawrence Livermore and Metal Improvement Company, Inc., won a coveted R and D 100 Award for their laser-peening process in 1998 (see S and TR, October 1998, pp. 12-13). Since that time, they've been developing uses for the technology with a number of industries, including automotive, medical, and aerospace. They've also developed an offshoot technique--laser peenmarking{trademark}--which provides a way to easily and clearly identify parts with a mark that is extremely difficult to counterfeit. Another outgrowth is a new peen-forming technology that allows complex contouring of problematic thick metal components such as the thick sections …

The effects of residual polishing slurry on the surface topology of highly-polished, Nd-doped metaphosphate laser glasses are reported. Glass samples were pitched polished using cerium oxide or zirconium oxide slurry at different pHs and then washed by different methods that allowed varying amounts of residual slurry to ''dry'' on the surface. Upon re-washing with water, some of the samples showed surface haze (scatter), which scaled with the amount of residual slurry. Profilometry measurements showed that the haze is the result of shallow surface pits (100 nm - 20 {micro}m wide x {approx}15 nm deep). Chemical analyses of material removed during rewashing, confirmed the removal of glass components as well as the preferential removal of modifier ions (e.g. K{sup 1+} and Mg{sup 2+}). The surface pits appear to result from reaction of the glass with condensed liquid at the slurry particle-glass interface that produces water-soluble phosphate products that dissolves away with subsequent water contact. Aggressive washing, to remove residual slurry immediately following polishing, can minimize surface haze on phosphate glasses. It is desirable to eliminate haze from glass used in high-peak-power lasers, since it can cause scatter-induced optical modulation that can cause damage to downstream optics.

Simulating the behavior of geologic materials under impact loading conditions requires the use of a constitutive model that includes the effects of bulking, yielding, damage, porous compaction and loading rate on the material response. This paper describes the development, implementation and calibration of a thermodynamically consistent constitutive model that incorporates these features. The paper also describes a computational study in which the model was used to perform numerical simulations of PILE DRIVER, a deeply-buried underground nuclear explosion detonated in granite at the Nevada Test Site. Particle velocity histories, peak velocity and peak displacement as a function of slant range obtained from the code simulations compare favorably with PILE DRIVER data. The simulated attenuation of peak velocity and peak displacement also agrees with the results from several other spherical wave experiments in granite.

We present a proposal for lowering the overhead of interface contract checking for science and engineering applications. Run-time enforcement of assertions is a well-known technique for improving the quality of software; however, the performance penalty is often too high for their retention during deployment, especially for long-running applications that depend upon iterative operations. With an efficient adaptive approach the benefits of run-time checking can continue to accrue with minimal overhead. Examples from scientific software interfaces being developed in the high performance computing research community will be used to measure the efficiency and effectiveness of this approach.

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As the threat to computer systems increases with the increasing use of computers as a tool in daily business activities, the need to securely configure those systems becomes more important. There are far too many intruders with access to the Internet and the skills and time to spend compromising systems to not spend the time necessary to securely configure a system. Hand-in-hand with the increased need for security are an increased number of items that need to be securely configured. Windows 2000 has about seven hundred security related policy settings, up from seventy two in Windows NT. While Windows 2000 systems are an extension of the Windows NT 4 architecture, there are considerable differences between these two systems, especially in terms of system and security administration. Operational policy, system security, and file security are other areas where Windows 2000 has expanded considerably beyond the domain model of Windows NT 4. The Windows NT 4 Domain model consists of domains of workstations that, with a single login, share resources and are administered together. The database of user settings and credentials resides in the domain server. Domains can trust other domains to expand the sharing of resources between users of multiple domains. …

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

Mercury continuous emissions monitoring systems (CEMs) are being implemented in over 800 coal-fired power plant stacks throughput the U.S. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor calibrators/generators. These devices are used to calibrate mercury CEMs at power plant sites. The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005 and vacated by a Federal appeals court in early 2008 required that calibration be performed with NIST-traceable standards. Despite the vacature, mercury emissions regulations in the future will require NIST traceable calibration standards, and EPA does not want to interrupt the effort towards developing NIST traceability protocols. The traceability procedures will be defined by EPA. An initial draft traceability protocol was issued by EPA in May 2007 for comment. In August 2007, EPA issued a conceptual interim traceability protocol for elemental mercury calibrators. The protocol is based on the actual analysis of the output of each calibration unit at several concentration levels ranging initially from …

Sulphate-reducing bacteria are anaerobes readily found in oxic-anoxic interfaces. Multiple defence pathways against oxidative conditions were identified in these organisms and proposed to be differentially expressed under different concentrations of oxygen, contributing to their ability to survive oxic conditions. In this study, Desulfovibrio vulgaris Hildenborough cells were exposed to the highest concentration of oxygen that sulphate-reducing bacteria are likely to encounter in natural habitats, and the global transcriptomic response was determined. 307 genes were responsive, with cellular roles in energy metabolism, protein fate, cell envelope and regulatory functions, including multiple genes encoding heat shock proteins, peptidases and proteins with heat shock promoters. Of the oxygen reducing mechanisms of D. vulgaris only the periplasmic hydrogen-dependent mechanism is up-regulated, involving the [NiFeSe]hydrogenase, formate dehydrogenase(s) and the Hmc membrane complex. The oxidative defence response concentrates on damage repair by metal-free enzymes. These data, together with the down regulation of the Fur operon, which restricts the availability of iron, and the lack of response of the PerR operon, suggest that a major effect of this oxygen stress is the inactivation and/or degradation of multiple metalloproteins present in D. vulgaris as a consequence of oxidative damage to their metal clusters.

Operation of the Next Generation Nuclear Plant (NGNP) with reduced reactor outlet temperature at full power was investigated for the High Temperature Electrolysis (HTE) hydrogen-production application. The foremost challenge for operation at design temperature is achieving an acceptably long service life for heat exchangers. In both the Intermediate Heat Exchanger (IHX) and the Process Heat Exchanger (PHX) (referred to collectively as high temperature heat exchangers) a pressure differential of several MPa exists with temperatures at or above 850 C. Thermal creep of the heat exchanger channel wall may severely limit heat exchanger life depending on the alloy selected. This report investigates plant performance with IHX temperatures reduced by lowering reactor outlet temperature. The objective is to lower the temperature in heat transfer channels to the point where existing materials can meet the 40 year lifetime needed for this component. A conservative estimate for this temperature is believed to be about 700 C. The reactor outlet temperature was reduced from 850 C to 700 C while maintaining reactor power at 600 MWt and high pressure compressor outlet at 7 MPa. We included a previously reported design option for reducing temperature at the PHX. Heat exchanger lengths were adjusted to reflect the …

Pacific Northwest National Laboratory (PNNL) obtained a Mettler Toledo floor scale for the purpose of testing it to determine whether it can replace the International Atomic Energy Agency’s (IAEA) cumbersome, hanging load cell. The floor scale is intended for use as a subsystem within PNNL’s nascent UF6 Cylinder Portal Monitor. The particular model was selected for its accuracy, size, and capacity. The intent will be to use it only for 30B cylinders; consequently, testing did not proceed beyond 8,000 lb.

This response demonstrates that the comment by Peeters et al. contains an incorrect and misleading interpretation of our paper [Hahm et al., Phys. Plasmas 15, 055902 (2008)] regarding the density gradient dependence of momentum pinch and the turbulent equipartition (TEP) theory.

Transmission system operators require near real time knowledge of reactive power capability to reliably operate large electric power transmission systems. Reactive power produced by, or capable of being produced by, a power generator is often estimated based on a series of mega volt amperes (MVA) capability curves for the generator. These curves indicate the ability of the generator to produce real and reactive power under a variety of conditions. In transmission planning and operating studies, it is often assumed, based on estimates for these capability curves, that the generator can provide its rated MVA capability output when needed for system stability However, generators may not always operate at levels depicted by the maximum MVA capability curve due to present constraints. Transmission system operators utilizing the generators’ capability curves for operation decisions regarding transmission system stability or for planning horizons may overestimate the capability of the generators to supply reactive power when required. Southern Company has enhanced GenVARR(TM), the system of plant data query, retrieval, and analysis and calculates the actual – not estimated -- remaining reactive power output capability. The remaining reactive output is considered spinning reserve and is displayed graphically to transmission control center and generating plant operators to …

PNNL developed a material balance assessment methodology based on conservation of mass for detecting leaks and mis-routings in pipeline transfer of double-shell tank waste at Hanford. The main factors causing uncertainty in these transfers are variable property and tank conditions of density, existence of crust, and surface disturbance due to mixer pump operation during the waste transfer. The methodology was applied to three waste transfers from Tanks AN-105 and AZ-102.

Validation is the process of determining whether the models in a computer code can describe the important phenomena in applications of interest. This report describes past work and proposed future work for validating the Gas Plant Analyzer and System Simulator (G-PASS) code. The G-PASS code was developed for simulating gas reactor and chemical plant system behavior during operational transients and upset events. Results are presented comparing code properties, individual component models, and integrated system behavior against results from four other computer codes. Also identified are two experiment facilities nearing completion that will provide additional data for individual component and integrated system model validation. The main goal of the validation exercise is to ready a version of G-PASS for use as a tool in evaluating vendor designs and providing guidance to vendors on design directions in nuclear-hydrogen applications.