The Plutonium Immobilization Program requires development of the process and plant prototypic equipment to immobilize surplus plutonium in ceramic for long-term storage. Because of the hazardous nature of plutonium, it was necessary to develop a remotely operable materials transfer system which can function within the confines of a glovebox. In support of this work at LLNL, such a material transfer system (MTS) was developed. This paper presents both the mechanical and controls parts making up this system, and includes photographs of the key components and diagrams of their assemblies, as well as a description of the control sequence used to validate the MTS capabilities.

The performance of NIF target designs is simulated in three dimensions using the HYDRA multiphysics radiation hydrodynamics code. In simulations of a cylindrical NIF hohlraum that include an imploding capsule, the motion of the wall material inside the hohlraum shows a high degree of axisymmetry. Laser radiation is able to propagate through the entrance hole for the required duration of the pulse. Gross hohlraum energetics in the simulation mirror the results from an axisymmetric simulation. A simulation of a copper-doped beryllium ablator NIF capsule carried out over large solid angle resolved the full spectrum of the most dangerous modes that grow from surface roughness. Hydrodynamic instabilities evolve into the weakly nonlinear regime. There is no evidence of low mode jetting driven by nonlinear mode coupling.

Recent attention has been given to the proper treatment of the planar traction-free surfaces which typically bound a computational box in three-dimensional dislocation dynamics. This paper presents an alternative to the use of the finite-element method for this purpose. Here, to annul the tractions produced by a sub-surface dislocation segment on a finite-area free surface S, a combination of an image dislocation segment, and a distribution of N prismatic rectangular Volterra dislocation loops meshing S is utilized. The image dislocation segment, with the proper sign selection of the Burgers vector components, annuls the shear stresses, and the normal stress component is annulled discretely at N collocation points representing the centers of the loops. The unknowns in this problem are the magnitudes of the N Burgers vectors for the loops. Once these are determined, one can back calculate the Peach-Koehler force acting on the sub-surface segment and representing the effect of the free surface. As expected, the accuracy of the method improves as the loops continuously decrease in size.

This article presents an implementation of periodic boundary conditions (PBC) for Dislocation Dynamics (DD) simulations in three dimensions (3D). We discuss fundamental aspects of PBC development, including preservation of translational invariance and line connectivity, the choice of initial configurations compatible with PBC and a consistent treatment of image stress. On the practical side, our approach reduces to manageable proportions the computational burden of updating the long-range elastic interactions among dislocation segments. The timing data confirms feasibility and practicality of PBC for large-scale DD simulations in 3D.

Confidence-Building Measures (CBMs) under the Comprehensive Nuclear-Test-Ban Treaty (CTBT) address the political goal of alleviating compliance concerns raised by chemical explosions and the technical goal of calibrating the International Monitoring System (IMS; ref. Article IV, E, and Part 111 of the Protocol to the treaty). The term ''calibration'' only appears in the treaty associated with CBMs and On-Site Inspection and has different meanings in each case. This difference can be illustrated through the use of a simple, conceptual equation:

Many non-silica aerogels are notably weak and fragile in monolithic form. Particularly, few monolithic aerogels with densities less than 50kg/m3 have any significant strength. It is especially difficult to prepare uncracked monoliths of pure alumina aerogels that are robust and moisture stable. In this paper, we discuss the synthesis of strong, stable, monolithic, high porosity (>98% porous) alumina aerogels, using a two-step sol-gel process. The alumina aerogels have a polycrystalline morphology that results in enhanced physical properties. Most of the measured physical properties of the alumina aerogels are superior to those for silica aerogels for equivalent densities.

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Laser conditioning by raster scanning KDP and DKDP crystals using Nd:YAG and XeCl excimer laser systems was demonstrated. The laser systems were evaluated to determine their respective feasibility of improving the damage thresholds of the harmonic materials for use on the National Ignition Facility (NIF). Crystals were first evaluated using an Nd:YAG laser (355 nm, 7.6 ns) by scanning 2 x 2 cm2 areas with sub-damage threshold fluences and then performing unconditioned (SA) damage tests at 355-nm in the respectively scanned regions. Subsequently, five KDP and DKDP samples of various damage quality were raster scanned in a similar fashion at MicroLas GmbH (Goettingen, Germany) using a commercial Lambda Physik Excimer system (XeCl, {lambda} = 308 nm, 20 ns). The samples treated in Germany were then tested at Livermore National Laboratory (LLNL) at 355 nm to demonstrate the excimer's potentia1 as an alternative conditioning source. The excimer scan results suggest that crystals can be treated at high fluence (50 Ycm2, 308-nm, 204s) levels without noticeable bulk damage. In addition, comparable conditioning is possible even with the fluence set at 30% of the 308-nm damage threshold. The laser damage tests with 355-nrn on the majority of the excimer laser-treated crystals demonstrates the …

Vacuum degrades the transmittance and catastrophic damage performance of fused-silica surfaces, both bare and silica-sol anti-reflective coated. These effects may be important in certain space application of photonics devices. When exposed to hundreds of 355-rim, 10-ns laser pulses with fluences in the 2-15 J/cm{sup 2} range, transmittance loss is due to both increased reflectance and absorption at the surface. Spectroscopic measurements show that the absorbed light induces broadband fluorescence from the visible to infrared and that the peak photoluminescence wavelength depends cumulative fluence. The effect appears to be consistent with the formation of surface SiO{sub x} (x<2) with progressively lower x as cumulative fluence increases. Conversely, low fluence CW UV irradiation of fluorescent sites in air reduces the fluorescence signal, which suggests a photochemical oxidation reaction back to Si0{sub 2}. The occurrence of catastrophic damage (craters that grow on each subsequent pulse) also increases in a vacuum relative to air for both coated and uncoated samples. In both cases, the 50% damage probability for 100 one-mm sites decreases from about 45 to 35 J/cm{sup 2} for superpolished fused silica at pressures in the 10{sup -6} Torr range. The damage probability distribution in 10 Torr of air is close to that …

Oxo-bridged manganese polynuclear complexes have applications in a variety of technologies, such as single-molecule nanomagnets, catalysis and photosynthetic redox chemistry. The reason that these types of compounds are capable of such important and varied technologies is thought to be because they possess ground states with large spin values. However, the electronic, structural and magnetochemical relationships are not well understood and need to be thoroughly investigated to adequately explain why Mn is such an integral part of so many useful processes. X-ray photoemission spectroscopy was used to study the Mn 3p, 3s and valence band electronic behavior as a function of Mn cluster structural properties, where the cluster size and nuclearity are systematically varied. Results show a chemical shift of the Mn 3p{sub 3/2,1/2} spin-orbit pair related to the cluster size and nuclearity. Also, the Mn 3s {sup 7}S and {sup 5}S final state multiplet components shift since it involves the binding energy of a ligand valence electron. In addition, the branching ratio of the {sup 7}S:{sup 5}S states is related to the 3s-3d electron correlation. Specifically, in the {sup 7}S state, the remaining 3s electron is well correlated with 3d electrons of parallel spin, while in the {sup 5}S state …

This article describes the design rationale, a C implementation, and conformance testing of a subset of the new Standard for the BLAS (Basic Linear Algebra Subroutines): Extended and Mixed Precision BLAS. Permitting higher internal precision and mixed input/output types and precisions allows us to implement some algorithms that are simpler, more accurate, and sometimes faster than possible without these features. The new BLAS are challenging to implement and test because there are many more subroutines than in the existing Standard, and because we must be able to assess whether a higher precision is used for internal computations than is used for either input or output variables. We have therefore developed an automated process of generating and systematically testing these routines. Our methodology is applicable to languages besides C. In particular, our algorithms used in the testing code will be valuable to all other BLAS implementors. Our extra precision routines achieve excellent performance--close to half of the machine peak Megaflop rate even for the Level 2 BLAS, when the data access is stride one.

Demo lower owning & operating costs by recovering exhaust energy Demo lower emissions by integrating w/diesel low NO{sub x} systems

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Evaluate performance of near-term exhaust emissions control technologies on a modern diesel vehicle over transient drive cycles; Phase 1: Independent (separate) evaluations of engine-out, OEM catalysts, CDPF, and NOx adsorber (Completed March 2000); Phase 2: Combine NOx adsorber and CDPF to evaluate/demonstrate simultaneous reduction of NOx and PM (Underway--interim results available); Establish potential for these technologies to help CIDI engines meet emission reduction targets; and Investigate short-term effects of fuel sulfur on emissions performance

To determine the impact of diesel fuel sulfur levels on emissions control devices that could lower emissions of oxides of nitrogen (NOX) and particulate matter (PM) from on-highway trucks and buses in the 2002-2004 model years. West Virginia University is evaluating: - Diesel Oxidation Catalysts - Lean NOX Catalysts

Demonstrate applicability of the CRT TM to both new 4-stroke and older 2-stroke diesel engines Document the emissions reductions available using CRT TM retrofits in conjunction with reduced sulfur diesel fuel Evaluate the durability of CRTs in rigorous New York City bus service Apply new measurement and monitoring technologies for PM and toxic emissions Compare diesel-CRTTM with CNG and diesel-electric hybrid buses

Experimental understanding of the diesel spray and combustion process at the fundamental level has helped advance the virtual lab simulation tools. The computational fluid dynamics (CFD)-based simulation has been globally verified in many engines, providing substantial credibility to the use of this technology in advanced engine development. This paper highlights the common aspects and differences between the smallbore HSDI and the larger displacement heavy-duty truck engine spray and combustion processes. Implications for combustion system strategies will be delineated. Detroit Diesel integrated ''Wired'' approach will be explained with pointers towards future tool enhancements.

This study included engine cell and vehicle tests. The engine cell tests are aimed at determining NOX reduction using the US transient and OICA emissions test cycles. These cycles will be included in future US HD emissions standards. The vehicle tests will show urea-SCR system performance during real-world operation. These tests will prove that the technology can be successfully implemented and demonstrated over-the-road. The program objectives are to: (a) apply urea-SCR to a US HD diesel engine; (b) determine engine cell emissions reduction during US-transient and OICA cycles; (c) apply urea-SCR to a US HD diesel truck; and (d) determine NOX reduction and urea consumption during over-the-road operation.

Ambient Toxics Monitoring Toxics Emissions Inventory Modeling/Risk Assessment.

Substantial progress has been made in reducing emissions and improving the performance of Diesel engines. Appears to be a lower limit for engine-out NOX of about 1 g/hp-hr. Serious difficulty in meeting Tier II or newly proposed H-D standards. Homogeneous charge compression ignition (HCCI) is an alternative IC engine combustion process that has the potential to: Provide diesel-like or higher efficiencies. Very low engine-out NOX due to low combustion temperatures. Very low particulate (PM) emissions. HCCI engine combustion is not well understood, and research is required to resolve technical barriers, including:

Evaluate the effects of diesel fuel sulfur on the performance of low temperature and high temperature Lean-NOx Catalysts. Evaluate the effects of up to 250 hours of aging on the performance of the Lean-NOx Catalysts with different fuel sulfur contents.

As evidenced by recent lawsuits brought against operators of large diesel truck fleets [1] and by the Consent Decree brought against the heavy-duty diesel manufacturers [2], the environmental and health effects of diesel engine emissions continue to be a significant concern. Reduction of diesel engine emissions has traditionally been achieved through a combination of fuel system, combustion chamber, and engine control modifications [3]. Catalytic aftertreatment has become common on modern diesel vehicles, with the predominant device being the diesel oxidation catalytic converter [3]. To enable advanced after-treatment devices and to directly reduce emissions, significant recent interest has focused on reformulation of diesel fuel, particularly the reduction of sulfur content. The EPA has man-dated that diesel fuel will have only 15 ppm sulfur content by 2007, with current diesel specifications requiring around 300 ppm [4]. Reduction of sulfur will permit sulfur-sensitive aftertreatment devices, continuously regenerating particulate traps, NOx control catalysts, and plasma assisted catalysts to be implemented on diesel vehicles [4]. Another method of reformulating diesel fuel to reduce emissions is to incorporate oxygen in the fuel, as was done in the reformulation of gasoline. The use of methyl tertiary butyl ether (MTBE) in reformulated gasoline has resulted in contamination of …

Determine the impact of fuel sulfur levels on emission control systems that could be implemented to lower emissions of NOx and PM from on-highway trucks in the 2002-2004 time frame.

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