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open access

HCCI Combustion: Analysis and Experiments

Description: Homogeneous charge compression ignition (HCCI) is a new combustion technology that may develop as an alternative to diesel engines with high efficiency and low NOx and particulate matter emissions. This paper describes the HCCI research activities being currently pursued at Lawrence Livermore National Laboratory and at the University of California Berkeley. Current activities include analysis as well as experimental work. On analysis, we have developed two powerful tools: a single zone model an… more
Date: May 14, 2001
Creator: Aceves, Salvador M.; Flowers, Daniel L.; Martinez-Frias, Joel; Smith, J. Ray; Dibble, Robert; Au, Michael et al.
open access

From plasma immersion ion implantation to deposition: A historical perspective on principles and trends

Description: Plasma immersion techniques of surface modification are known under a myriad of names. The family of techniques reaches from pure plasma ion implantation, to ion implantation and deposition hybrid modes, to modes that are essentially plasma film deposition with substrate bias. In the most general sense, all plasma immersion techniques have in common that the surface of a substrate (target) is exposed to plasma and that relatively high substrate bias is applied. The bias is usually pulsed. In th… more
Date: June 14, 2001
Creator: Anders, Andre
open access

Tc-99 Analysis with Picogram Sensitivity by a Resin-Bead Mass-Spectrometric Isotope-Dilution Technique

Description: This paper describes an improved isotope-dilution mass-spectrometric procedure. Important improvements are a highly selective (yet non-critical) isolation scheme devised primarily from the work of Maeck, et al. and a significant increase in the mass spectrometric ionization efficiency for technetium obtained by analyzing the technetium absorbed on individual anion exchange resin beads.
Date: March 14, 2001
Creator: Anderson, T. J.
open access

Partial (gamma)-Ray Cross Sections for the Reaction 239Pu(n,2n(gamma)i) and the 239Pu(n,2n) Cross Section

Description: Absolute partial {gamma}-ray cross sections for production of discrete {gamma} rays in the {sup 239}Pu(n,2n{gamma}i){sup 238}Pu reaction have been measured. The experiments were performed at LANSCE/WNR on the 60R flight line. Reaction {gamma}-rays were measured using the large-scale Compton-suppressed array of Ge detectors, GEANIE. The motivation for this experiment, an overview of the partial {gamma}-ray cross-section measurement, and an introduction to the main experimental issues will be pre… more
Date: September 14, 2001
Creator: Beacker, J. A.; Bernstein, L. A.; Younes, W.; McNabb, D. P.; Garrett, P. E.; Archer, D. et al.
open access

Numerical simulation of premixed turbulent methane combustion

Description: In this paper we study the behavior of a premixed turbulent methane flame in three dimensions using numerical simulation. The simulations are performed using an adaptive time-dependent low Mach number combustion algorithm based on a second-order projection formulation that conserves both species mass and total enthalpy. The species and enthalpy equations are treated using an operator-split approach that incorporates stiff integration techniques for modeling detailed chemical kinetics. The metho… more
Date: December 14, 2001
Creator: Bell, John B.; Day, Marcus S. & Grcar, Joseph F.
open access

Stochastic algorithms for the analysis of numerical flame simulations

Description: Recent progress in simulation methodologies and new, high-performance parallel architectures have made it is possible to perform detailed simulations of multidimensional combustion phenomena using comprehensive kinetics mechanisms. However, as simulation complexity increases, it becomes increasingly difficult to extract detailed quantitative information about the flame from the numerical solution, particularly regarding the details of chemical processes. In this paper we present a new diagnosti… more
Date: December 14, 2001
Creator: Bell, John B.; Day, Marcus S.; Grcar, Joseph F. & Lijewski, Michael J.
open access

Detailed modeling and laser-induced fluorescence imaging of nitric oxide in a NH(i)-seeded non-premixed methane/air flame

Description: In this paper we study the formation of NO in laminar, nitrogen diluted methane diffusion flames that are seeded with ammonia in the fuel stream. We have performed numerical simulations with detailed chemistry as well as laser-induced fluorescence imaging measurements for a range of ammonia injection rates. For comparison with the experimental data, synthetic LIF images are calculated based on the numerical data accounting for temperature and fluorescence quenching effects. We demonstrate good … more
Date: December 14, 2001
Creator: Bell, John B.; Day, Marcus S.; Grcar, Joseph F.; Bessler, Wolfgang G.; Schulz, Christof; Glarborg, Peter et al.
open access

Rare Decay Results from KTeV and ({rho}{sub CKM}, {eta}{sub CKM})

Description: Rare decay results from KTeV are reviewed, emphasizing modes that in principle provide information about the CKM matrix. The KTeV results shown here are from the 1997 data sample, which consists of about 2.7 x 10{sup 11} K{sub L}{sup 0} decay samples. KTeV also took data in 1999, giving a total data sample about 2.5 times what is presented here for three body decays and about 3.2 times what is presented here for four body decays. A summary of the KTeV detector is in the Appendix. Our recent res… more
Date: February 14, 2001
Creator: Bellantoni, L.
open access

The influence of cut off lows on sulfate burdens over the North Atlantic during April, 1987

Description: The authors have presented examples from a modeling study of the development of sulfur burdens over North America, the North Atlantic Ocean and Europe during April, 1987 using observation-derived meteorological data to represent the actual conditions for this period, focusing on the influence of cut-off lows on SO{sub 2} and sulfate column burdens over the North Atlantic Ocean. The analysis demonstrates that these systems can serve either as sources or sinks of sulfate, and that the major facto… more
Date: January 14, 2001
Creator: Benkovitz, C. M.; Miller, M. A.; Schwartz, S. E. & Kwon, O. U.
open access

Effect of Internal Alpha Radiation on Borosilicate Glass Containing Simulated Radioactive Waste

Description: To evaluate borosilicate glass as a matrix for long-term storage of radioactive waste, samples containing 45 wt. percent simulated waste along with 0.5 wt. percent 244Cm or 1 wt. percent 238Pu as alpha particle emitters were synthesized. A glass containing 238Pu without simulated waste was also made. Effects of internal alpha radiolysis from 244Cm and 238Pu on physical stability, leachability, and dilatation of the glasses were examined. Results confirm that glass may be a desirable matrix for … more
Date: March 14, 2001
Creator: Bibler, N.E.
open access

Ductilization of Cr via Oxide Dispersions

Description: Work by Scruggs et al. in the 1960's demonstrated that up to 20% tensile ductility could be achieved at room-temperature in sintered and extruded powder metallurgical Cr alloyed with MgO. During sintering, much of the MgO converts to a MgCr{sub 2}O{sub 4} spinel, which was hypothesized to getter nitrogen from the Cr, rendering it ductile. Recent efforts at Oak Ridge National Laboratory (ORNL) have succeeded in duplicating this original effect. Preliminary results suggest that the ductilization … more
Date: February 14, 2001
Creator: Brady, M.P.
open access

Waveguide Fabrication in Fused Silica Using Tightly Focused Femtosecond Laser Pulses

Description: Refractive index changes have been induced inside bulk fused silica by using femtosecond (fs) laser pulses tightly focused inside the material. Waveguides have been fabricated inside the glass by scanning the glass with respect to the focal point of the laser beam. The refractive index change is estimated to be {approx} 10{sup -4}. Other more complex three-dimensional structures have also been fabricated (curved waveguides, splitters, and interferometers). We also report on fluorescence spectro… more
Date: December 14, 2001
Creator: Chan, J W; Huser, T; Risbud, S H & Krol, D M
open access

Comparison of Particulate Collection in Probes and on Filters

Description: Major radionuclide emissions from the Department of Energy's Y-12 National Security Complex are nuclides of uranium which are emitted as a particulate. The radionuclide NESHAP regulation requires stack sampling to be conducted in accordance with ANST Standard N13.1, 1969. Appendix B of this standard requires in every case where sampling delivery lines are used that an evaluation should be made of deposition in these lines. A number of Y-12 Complex stacks are fitted with continuous samplers… more
Date: June 14, 2001
Creator: Eaton, J.M. & Humphreys, M.P.
open access

Ultralight Stainless Steel Urban Bus Concept

Description: While stainless steel buses are certainly not new, this study reveals opportunities for substantial improvements in structural performance.The objective of this project was to investigate the mass saving potential of ultra-high strength stainless steel as applied to the structure of a full size urban transit bus.The resulting design for a low floor,hybrid bus has an empty weight less than half that of a conventional transit bus.The reduced curb weight allows for a greater payload,without exceed… more
Date: May 14, 2001
Creator: Emmons, J. Bruce & Blessing, Leonard J.
open access

Advanced Aerodynamic Devices to Improve the Performance, Economics, Handling, and Safety of Heavy Vehicles

Description: Research is being conducted at the Georgia Tech Research Institute (GTRI) to develop advanced aerodynamic devices to improve the performance, economics, stability, handling and safety of operation of Heavy Vehicles by using previously-developed and flight-tested pneumatic (blown) aircraft technology. Recent wind-tunnel investigations of a generic Heavy Vehicle model with blowing slots on both the leading and trailing edges of the trailer have been conducted under contract to the DOE Office of H… more
Date: May 14, 2001
Creator: Englar, Robert J.
open access

Detector Requirements to Curb Nuclear Smuggling

Description: The problem of stopping nuclear smuggling of terrorist nuclear devices is a complex one, owing to the variety of pathways by which such a device can be transported. To fashion new detection systems that improve the chances of detecting such a device, it is important to know the various requirements and conditions that would be imposed on them by both the types of devices that might be smuggled and by the requirement that it not overly interfere with the transportation of legitimate goods. Requi… more
Date: November 14, 2001
Creator: Erickson, S A
open access

Tapered undulator for SASE FELs

Description: We discuss the use of tapered undulators to enhance the performance of free-electron lasers (FELs) based upon self-amplified spontaneous emission (SASE), where the radiation tends to have a relatively broad bandwidth, limited temporal phase coherence, and large amplitude fluctuations. Using the polychromatic FEL simulation code GINGER, we numerically demonstrate the effectiveness of a tapered undulator for parameters corresponding to the existing Argonne low-energy undulator test line (LEUTL) F… more
Date: September 14, 2001
Creator: Fawley, William M.; Huang, Zhirong; Kim, Kwang-Je & Vinokurov, Nikolai A.
open access

The deuteron: structure and form factors

Description: A brief review of the history of the discovery of the deuteron in provided. The current status of both experiment and theory for the elastic electron scattering is then presented.
Date: February 14, 2001
Creator: Garcon, M. & Orden, J.W. Van
open access

A Preliminary Study of Energy Recovery in Vehicles by Using Regenerative Magnetic Shock Absorbers

Description: Road vehicles can expend a significant amount of energy in undesirable vertical motions that are induced by road bumps, and much of that is dissipated in conventional shock absorbers as they dampen the vertical motions. Presented in this paper are some of the results of a study aimed at determining the effectiveness of efficiently transforming that energy into electrical power by using optimally designed regenerative electromagnetic shock absorbers. In turn, the electrical power can be used to … more
Date: May 14, 2001
Creator: Goldner, R. B.; Zerigian, P. & Hull, J. R.
open access

Gauge unification in higher dimensions

Description: A complete 5-dimensional SU(5) unified theory is constructed which, on compactification on the orbifold with two different Z{sub 2}'s (Z{sub 2} and Z{sub 2}{prime}), yields the minimal supersymmetric standard model. The orbifold accomplishes SU(5) gauge symmetry breaking, doublet-triplet splitting, and a vanishing of proton decay from operators of dimension 5. Until 4d supersymmetry is broken, all proton decay from dimension 4 and dimension 5 operators is forced to vanish by an exact U(1){sub R… more
Date: January 14, 2001
Creator: Hall, Lawrence & Nomura, Yasunori
open access

Safety Grounding Approach for the National Ignition Facility Power Conditioning System

Description: This paper describes a set of analyses and tests performed to evaluate approaches to provide a safe and robust grounding approach for the main Power Conditioning System (PCS) in the National Ignition Facility (NIF) facility presently under construction at the Lawrence Livermore National Laboratory (LLNL). The Power Conditioning System consists of up to 192 capacitor bank modules, each storing 2.2 MJ and capable of producing a peak current over 500 kA. The grounding system must minimize touch po… more
Date: June 14, 2001
Creator: Hammon, J; E, Fulkerson S; Gagnon, B & Anderson, R
open access

Phase Transformation Hysteresis in a Plutonium Alloy System: Modeling the Resistivity during the Transformation

Description: We have induced, measured, and modeled the {delta}-{alpha}' martensitic transformation in a Pu-Ga alloy by a resistivity technique on a 2.8-mm diameter disk sample. Our measurements of the resistance by a 4-probe technique were consistent with the expected resistance obtained from a finite element analysis of the 4-point measurement of resistivity in our round disk configuration. Analysis by finite element methods of the postulated configuration of {alpha}' particles within model {delta} grains… more
Date: November 14, 2001
Creator: Haslam, J. J.; Wall, M. A.; Johnson, D. L.; Mayhall, D. J. & Schwartz, A. J.
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