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Cooperative sentry vehicles and differential GPS leapfrog

Description: As part of a project for the Defense Advanced Research Projects Agency, Sandia National Laboratories Intelligent Systems and Robotics Center is developing and testing the feasibility of using a cooperative team of robotic sentry vehicles to guard a perimeter, perform a surround task, and travel extended distances. This paper describes the authors most recent activities. In particular, this paper highlights the development of a Differential Global Positioning System (DGPS) leapfrog capability th… more
Date: June 7, 2000
Creator: Feddema, John T.; Lewis, Christopher L. & LaFarge, Robert A.
Partner: UNT Libraries Government Documents Department
open access

ITER CS Model Coil and CS Insert Test Results

Description: 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 … more
Date: September 7, 2000
Creator: Martovetsky, N.; Michael, P.; Minervini, J.; Radovinsky, A.; Takayasu, M.; Thome, R. et al.
Partner: UNT Libraries Government Documents Department
open access

Surface chemistry effects in finite element modeling of heat transfer in (micron)-fuel cells

Description: 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 m… more
Date: December 7, 2000
Creator: Havstad, M
Partner: UNT Libraries Government Documents Department
open access

Dynamics of Supersymmetric SU(n_c) and USp(2n_c) Gauge Theories

Description: We study dynamical flavor symmetry breaking in the context of a class of N=1 supersymmetric SU(n_c) and USp(2 n_c) gauge theories, constructed from the exactly solvable N=2 theories by perturbing them with small adjoint and generic bare hypermultiplet (quark) masses. We find that the flavor U(n_f) symmetry in SU(n_c) theories is dynamically broken to $U(r)\times U(n_f-r)$ groups for $n_f \leq n_c$. In the r=1 case the dynamical symmetry breaking is caused by the condensation of monopoles in the… more
Date: January 7, 2000
Creator: Carlino, Giuseppe; Konishi, Kenichi & Murayama, Hitoshi
Partner: UNT Libraries Government Documents Department
open access

Plutonium Disposition by Immobilization

Description: The ultimate goal of the Department of Energy (DOE) Immobilization Project is to develop, construct, and operate facilities that will immobilize between 17 to 50 tonnes (MT) of U.S. surplus weapons-usable plutonium materials in waste forms that meet the ''spent fuel'' standard and are acceptable for disposal in a geologic repository. Using the ceramic can-in-canister technology selected for immobilization, surplus plutonium materials will be chemically combined into ceramic forms which will be … more
Date: March 7, 2000
Creator: Gould, T.; DiSabatino, A. & Mitchell, M.
Partner: UNT Libraries Government Documents Department
open access

High Energy Gamma Rays from p+X, X=Cu, Ag, Au at 34 MeV

Description: In this paper we present results from the measurement of the gamma ray yield in the reaction of 34-MeV protons on Cu, Ag and Au. The protons were produced by the University of Washington superconducting linac. The gamma rays were measured using a large NaI and two large BaF{sub 2} detectors. Angular distributions were obtained for each of the three targets. Data for the Cu and Ag target were taken at six lab angles between 35 and 135 degrees, while data were taken at eight lab angles between 35… more
Date: March 7, 2000
Creator: Luke, S. J.; Dietrich, F. S.; Chadwick, M. B.; Gossett, C. A.; Kaplan, M. S.; McLain, B. T. et al.
Partner: UNT Libraries Government Documents Department
open access

Debris Characterization Diagnostic for the National Ignition Facility

Description: Generation of debris from targets and by x-ray ablation of surrounding materials will be a matter of concern for experimenters and the operations staff at the National Ignition Facility (NIF). Target chamber and final optics protection, for example debris shield damage, and efficient facility operation drive the interest for the NIF staff. Experimenters are primarily concerned with diagnostic survivability, separation of mechanical versus radiation induced test object response in the case of ef… more
Date: June 7, 2000
Creator: Miller, M. C.; Celeste, J. R.; Suter, L. J.; Tobin, M. T.; Grun, J.; Davis, J. F. et al.
Partner: UNT Libraries Government Documents Department
open access

Laboratory Astrophysics using a Spare XRS Microcalorimeter

Description: The XRS instrument on Astro-E is a fully self-contained microcalorimeter x-ray instrument capable of acquiring, optimally filtering, and characterizing events for 32 independent pixels. We have recently integrated a full engineering model XRS detector system into a laboratory cryostat for use on the electron beam ion trap (EBIT) at Lawrence Livermore National Laboratory. The detector system contains a microcalorimeter array with 32 instrumented pixels heat sunk to 60 mK using an adiabatic demag… more
Date: August 7, 2000
Creator: Porter, F. S.; Audley, M. D.; Beiersdorfer, P.; Boyce, K. R.; Brekosky, R. P.; Brown, G. V. et al.
Partner: UNT Libraries Government Documents Department
open access

The National Ignition Facility Project: An Update

Description: The National Ignition Facility (NIT) consists of 192 forty-centimeter-square laser beams and a 10-m-diameter target chamber. Physical construction began in 1997. The Laser and Target Area Building and the Optics Assembly Building were the first major construction activities, and despite several unforeseen obstacles, the buildings are now 92% complete and have been done on time and within cost. Prototype component development and testing has proceeded in parallel. Optics vendors have installed f… more
Date: December 7, 2000
Creator: Hogan, W.J.; Moses, E.; Warner, B.; Sorem, M.; Soures, J. & Hands, J.
Partner: UNT Libraries Government Documents Department
open access

Part 1: Participatory Ergonomics Approach to Waste Container Handling Utilizing a Multidisciplinary Team

Description: This multidisciplinary team approach to waste container handling, developed within the Grassroots Ergonomics process, presents participatory ergonomic interpretations of quantitative and qualitative aspects of this process resulting in a peer developed training. The lower back, shoulders, and wrists were identified as frequently injured areas, so these working postures were a primary focus for the creation of the workers' training. Handling procedures were analyzed by the team to identify commo… more
Date: February 7, 2000
Creator: Zalk, D.M.; Tittiranonda, P.; Burastero, S.; Biggs, T.W.; Perry, C.M.; Tageson, R. et al.
Partner: UNT Libraries Government Documents Department
open access

Risk-Based Management of Contaminated Groundwater: The Role of Geologic Heterogeneity, Exposure and Cancer Risk in Determining the Performance of Aquifer Remediation

Description: The effectiveness of aquifer remediation is typically expressed in terms of a reduction in contaminant concentrations relative to a regulated maximum contaminant level (MCL), and is usually confined by sparse monitoring data and/or simple model calculations. Here, the effectiveness of remediation is examined from a risk-based perspective that goes beyond the traditional MCL concept. A methodology is employed to evaluate the health risk to individuals exposed to contaminated household water that… more
Date: April 7, 2000
Creator: Maxwell, R. M.; Carle, S. F. & Tompson, A. F. B.
Partner: UNT Libraries Government Documents Department
open access

Preconditioning Newton-Krylor Methods for Variably Saturated Flow

Description: In this paper, we compare the effectiveness of three preconditioning strategies in simulations of variably saturated flow. Using Richards' equation as our model, we solve the nonlinear system using a Newton-Krylov method. Since Krylov solvers can stagnate, resulting in slow convergence, we investigate different strategies of preconditioning the Jacobian system. Our work uses a multigrid method to solve the preconditioning systems, with three different approximations to the Jacobian matrix. One … more
Date: January 7, 2000
Creator: Woodward, C. S. & Jones, J. E.
Partner: UNT Libraries Government Documents Department
open access

Pthreads vs MPI Parallel Performance of Angular-Domain Decomposed S

Description: Two programming models for parallelizing the Angular Domain Decomposition (ADD) of the discrete ordinates (S{sub n}) approximation of the neutron transport equation are examined. These are the shared memory model based on the POSIX threads (Pthreads) standard, and the message passing model based on the Message Passing Interface (MPI) standard. These standard libraries are available on most multiprocessor platforms thus making the resulting parallel codes widely portable. The question is: on a f… more
Date: May 7, 2000
Creator: Azmy, Y. Y. & Barnett, D. A.
Partner: UNT Libraries Government Documents Department
open access

Nondestructive evaluation and assay for the plutonium ceramification test facility

Description: Lawrence Livermore National Laboratory (LLNL) has conducted design and testing activities of the Nondestructive Assay/Evaluation (NDA/NDE) system that will be installed to support the Plutonium Ceramification Test Facility (PuCTF). PuCTF immobilizes plutonium using the ceramic can-in-canister technology. The overall function of the NDA/NDE System is to ensure that sintered pucks contain the appropriate materials for ceramification process control, special nuclear materials (SNM) accountability,… more
Date: March 7, 2000
Creator: Mitchell, M.; Pugh, D. & Wang, T. F.
Partner: UNT Libraries Government Documents Department
open access

National Ignition Facility Project: An Update

Description: The National Ignition Facility (NIF) consists of 192 forty-centimeter-square laser beams and a 10-m-diameter target chamber. Physical construction began in 1997. The Laser and Target Area Building and the Optics Assembly Building were the first major construction activities, and despite several unforeseen obstacles, the buildings are now 92% complete and have been done on time and within cost. Prototype component development and testing has proceeded in parallel. Optics vendors have installed f… more
Date: December 7, 2000
Creator: Hogan, W J; Moses, E; Warner, B; Sorem, M; Soures, J & Hands, J
Partner: UNT Libraries Government Documents Department
open access

Evidence of biogenic corrosion of titanium after exposure to a continuous culture of thiobacillus ferrooxidans grown in thiosulfate medium

Description: Experiments were undertaken to evaluate extreme conditions under which candidate materials intended for use in a proposed nuclear waste repository might be susceptible to corrosion by endogenous microorganisms. Thiobucillus ferrooxidans, a sulfur-oxidizing bacterium, was grown in continuous culture using thiosulfate as an energy source; thiosulfate is oxidized to sulfate as a metabolic endproduct by this organism. Culture conditions were optimized to produce a high-density, metabolically active… more
Date: December 7, 2000
Creator: Horn, J M; Martin, S I & Masterson, B
Partner: UNT Libraries Government Documents Department
open access

Chemical Kinetics of Hydrocarbon Ignition in Practical Combustion Systems

Description: Chemical kinetic factors of hydrocarbon oxidation are examined in a variety of ignition problems. Ignition is related to the presence of a dominant chain branching reaction mechanism that can drive a chemical system to completion in a very short period of time. Ignition in laboratory environments is studied for problems including shock tubes and rapid compression machines. Modeling of the laboratory systems are used to develop kinetic models that can be used to analyze ignition in practical sys… more
Date: July 7, 2000
Creator: Westbrook, C.K.
Partner: UNT Libraries Government Documents Department
open access

Separations technologies supporting the development of a deployable ATW system

Description: A program has been initiated for the purpose of developing the chemical separations technologies necessary to support a large Accelerator Transmutation of Waste (ATW) system capable of dealing with the projected inventory of spent fuel from the commercial nuclear power stations in the United States. The first several years of the program will be directed toward an elucidation of related technical issues and to the establishment, by means of comprehensive trade studies, of an optimum configurati… more
Date: January 7, 2000
Creator: Laidler, J. J.
Partner: UNT Libraries Government Documents Department
open access

Experimental study of sin 2 {beta} and sin 2 {alpha}

Description: Detailed measurements of CP violation in B meson decay are on the horizon. Here the author reviews the status of current measurements of sin 2{beta} made at LEP and CDF. These yield an average of sin 2{beta} = 0.82 {+-} 0.39, giving 97% confidence that {beta} is greater than 0, evidence that CP violation occurs in B decay. He reviews predictions for the precision one can expect on sin 2{beta} and sin 2{alpha} in the next few years.
Date: March 7, 2000
Creator: Truschuk, W.
Partner: UNT Libraries Government Documents Department
open access

Thermal stability of electrodes in Lithium-ion cells

Description: Differential scanning calorimetry (DSC) analysis was used to identify thermal reactions in Sony-type lithium-ion cells and to correlate these reactions with interactions of cell constituents and reaction products. An electrochemical half-cell was used to cycle the anode and cathode materials and to set the state-of-charge (SOC). Three temperature regions of interaction were identified and associated with the SOC (degree of Li intercalation) of the cell. Anodes were shown to undergo exothermic r… more
Date: February 7, 2000
Creator: Roth, Emanuel P. & Nagasubramanian, Ganesan
Partner: UNT Libraries Government Documents Department
open access

Diffraction results from the Tevatron

Description: Recent results on dijet production in single diffraction and double pomeron exchange at the Tevatron are presented. Single diffraction results are compared with predictions from Monte Carlo models and expectations from results obtained in diffractive deep inelastic scattering experiments at HERA. Double pomeron exchange results are compared with corresponding single diffraction results to test factorization.
Date: June 7, 2000
Creator: Hatakeyama, Ken
Partner: UNT Libraries Government Documents Department
open access

Investigation of gas flow in long and narrow channels

Description: To minimize the viscous flow losses in a microsystem for chemical analysis, the authors have investigated gas flow in long capillary tubes and microchannels to characterize the flow behavior. Both experimental results and theoretical predictions indicate that gas flow in long and narrow channels, as in capillary tubes or rectangular channels, compressibility effect is very important. This leads to a higher mass flow rate than predicted by the incompressible flow model. Different computational f… more
Date: February 7, 2000
Creator: WONG,CHUNGNIN C.; ZOELLER,TRACIE L.; ADKINS,DOUGLAS R. & SHADID,JOHN N.
Partner: UNT Libraries Government Documents Department
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