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Discovery of the Most Distant Supernovae and the Quest for Omega

Description: A search for cosmological supernovae has discovered a number of a type la supernovae. In particular, one at z = 0.458 is the most distant supernova yet observed. There is strong evidence from measurements of nearby type Ia supernovae that they can be considered as 'standard candles'. We plan to use these supernovae to measure the deceleration in the general expansion of the universe. The aim of our experiment is to try and observe and measure about 30 such distant supernovae in order to obtain … more
Date: May 1, 1994
Creator: Goldhaber, G.; Boyle, B.; Bunclark, P.; Carter, D.; Ellis, R.; Gabi, S. et al.
Partner: UNT Libraries Government Documents Department
open access

['UNT professor offers expertise of Barnes collection', May 22, 1994]

Description: An article from the newspaper the Denton Record-Chronicle written by Tim Leenerts. The piece discusses the lectures given by Dr. R. William McCarter on the Barnes collection, which was being shown at the Kimbell Art Museum in Fort Worth.
Date: May 22, 1994
Creator: Leenerts, Tim
Partner: UNT Libraries Special Collections
open access

UEDGE and DEGAS modeling of the DIII-D scrape-off layer plasma. Revision 1

Description: This paper presents work to develop benchmarked theoretical models of scrape-off-layer (SOL) characteristics in diverted tokamaks by comparing shot simulations using the UEDGE plasma fluid and DEGAS neutral transport codes to measurements of the DIII-D SOL plasma. The experimental data include the radial profiles of n{sub e} T{sub e}, and T{sub i}, the divertor exhaust power, the intensity of H{sub {alpha}} emission, and profiles of the radiated power. A very simple model of the anomalous perpe… more
Date: May 1, 1994
Creator: Fenstermacher, M. E.; Porter, G. D.; Rensink, M. E.; Rognlien, T. D.; Allen, S. L.; Hill, D. N. et al.
Partner: UNT Libraries Government Documents Department
open access

Committee on Interagency Radiation Research and Policy Coordination (CIRRPC)

Description: Enclosed are proceedings of the workshop on Internal Dosimetry held on Atlanta, Georgia in April 1992. The recommendations from the Workshop were considered by the CIRRPC Subpanel on Occupational Radiation Protection Research in identifying those areas to be undertaken by individual Federal Agencies or in cooperative efforts. This document presents summaries of the following sessions: A.1 Applications and limitations of ICRP and other metabolic models, A.2 Applications and implementation of pro… more
Date: May 10, 1994
Partner: UNT Libraries Government Documents Department
open access

Linear-size nonobtuse triangulation of polygons

Description: We give an algorithm for triangulating n-vertex polygonal regions (with holes) so that no angle in the final triangulation measures more than {pi}/2. The number of triangles in the triangulation is only 0(n), improving a previous bound of 0(n{sup 2}), and the worst-case running time is 0(n log{sup 2} n). The basic technique used in the algorithm, recursive subdivision by disks, is new and may have wider application in mesh generation. We also report on an implementation of our algorithm.
Date: May 1, 1994
Creator: Bern, M.; Mitchell, S. & Ruppert, J.
Partner: UNT Libraries Government Documents Department
open access

Structural performance of a Multipurpose Canister shell for HLNW under normal handling conditions

Description: A Multipurpose Canister (MPC) is analyzed for critical stresses that occur during normal handling conditions and accidental scenarios. Linear and Non-linear Finite Element Analysis is performed and the stresses at various critical locations in the MPC and its weldments are studied extensively. Progressive failure analysis of the MPC`s groove and fillet welds, is presented. The structural response of the MPC to dynamic lifting loads, to loads resulting from an accidental slippage of a crane cabl… more
Date: May 1, 1994
Creator: Ladkany, S. G. & Rajagopalan, R.
Partner: UNT Libraries Government Documents Department
open access

Flow visualization for Lagrangian particle methods

Description: In particle methods, each particle represents a finite region over which there is a distribution of the field quantity of interest. The field value at any point is calculated by summing the distribution functions for all the particles. This summation procedure does not require the use of any connectivities to generate continuous fields. Various AVS modules and networks have been developed that enable us to visualize the results from particle methods. This will be demonstrated by visualizing a n… more
Date: May 1, 1994
Creator: Glass, M. W. & Kempka, S. N.
Partner: UNT Libraries Government Documents Department
open access

Critical-state flux-density profiles in type-II superconducting thin-film strips and disks

Description: When a weak magnetic field is applied to a superconducting strip or disk of thickness d (of the order of the penetration depth {lambda}) much less than its width or radius, induced super-currents flow so as to prevent magnetic flux from penetrating the superconductor (except within {lambda} of the edge). A stronger field causes vortices to enter, and the profiles of the macroscopic flux density B are determined by critical-state equations describing bulk pinning. Near the sample edge, where the… more
Date: May 1, 1994
Creator: Clem, J. R.
Partner: UNT Libraries Government Documents Department
open access

Analytical procedures for waste minimization and pollution prevention

Description: Procedures exist for waste characterization, but waste minimization and pollution prevention have not usually played a role in development of these procedures. The US Department of Energy (DOE) expects to require several million characterizations over a 30-year period to accomplish the Department`s goals in environmental restoration and waste management. The waste generated by the analytical procedures used for characterizations is a significant source of new DOE waste. We have begun investigat… more
Date: May 1, 1994
Creator: Green, D. W.; Smith, L. L.; Crain, J. S.; Boparai, A. S. & Schilling, J. B.
Partner: UNT Libraries Government Documents Department
open access

Lightweight CO{sub 2}-resistant cements for geothermal well completions

Description: Alkali metal catalyzed reactions between CO{sub 2}-containing brines and portland cement-based well cements can result in rapid strength reductions, increased permeability and casing corrosion, reduced well life, increased costs, and environmental concerns. Materials formed by acid-base reactions between calcium aluminate compounds and phosphate-containing solutions yield high strength, low permeability and CO{sub 2}-resistant cements when cured in hydrothermal environments. The cementing formu… more
Date: May 1, 1994
Creator: Kukacka, L. E. & Sugama, T.
Partner: UNT Libraries Government Documents Department
open access

Design of the divertor Thomson scattering system on DIII-D

Description: Local measurements of n{sub e} and T{sub e} in the divertor region are necessary for a more complete understanding of divertor physics. We have designed an extension to the existing multipulse Thomson scattering system to measure n{sub e} in the range 5 {times} 10{sup 18} to 5 {times} 10{sup 20} m{sup {minus}3} and T{sub e} 5--500 eV, with 1 cm resolution from 1--21 cm above the floor of the DIII-D vessel, in the region of the X-point for lower single-null diverted plasmas. One of the existing … more
Date: May 1, 1994
Creator: Carlstrom, T. N.; Foote, J. H.; Nilson, D. G. & Rice, B. W.
Partner: UNT Libraries Government Documents Department
open access

Stopping and Fermi/Bose effects in 14.6 A {center_dot} GeV/c nucleus-nucleus collisions

Description: For central p+A and Si+A collisions, the average projectile baryon stopping has been determined. The average rapidity loss of the projectile baryons is 0.85{+-}0.1, 1.35{+-}0.1, 1.50{+-}0.28, 1.66{+-}0.21, 1.88{+-}0.17 and 2.11{+-}0.13 for Si+Al, Si+Au, p+Be, p+Al, p+Cu and p+Au, respectively. For central Si+Au collisions, significant deviations from exponential M{sub {perpendicular}} dependence of the differential cross-sections are found. Protons are suppressed at low P{sub {perpendicular}} a… more
Date: May 1, 1994
Creator: Parsons, C. G.
Partner: UNT Libraries Government Documents Department
open access

DDT modeling and shock compression experiments of porous or damaged energetic materials

Description: In this presentation, we present modeling of DDT in porous energetic materials and experimental studies of a time-resolved, shock compression of highly porous inert and reactive materials. This combined theoretical and experimental studies explore the nature of the microscale processes of consolidation, deformation and reaction which are key features of the shock response of porous or damaged energetic materials. The theoretical modeling is based on the theory of mixtures in which multiphase mi… more
Date: May 1, 1994
Creator: Baer, M. R.; Anderson, M. U. & Graham, R. A.
Partner: UNT Libraries Government Documents Department
open access

Math and science illiteracy: Social and economic impacts

Description: Today`s highly competitive global economy is being driven by increasingly rapid technological development. This paper explores the problems of math and science illiteracy in the United States and the potential impact on our economic survival in this environment during the next century. Established educational methods that reward task performance, emphasize passive lecture, and fail to demonstrate relevance to real life are partly to blame. Social norms, stereotypes, and race and gender bias als… more
Date: May 1, 1994
Creator: Williams, J. L.
Partner: UNT Libraries Government Documents Department
open access

Numerical simulation of dynamic fracture and failure in solids

Description: Numerical simulation of dynamic fracture and failure processes in solid continua using Lagrangian finite element techniques is the subject of discussion in this investigation. The specific configurations in this study include penetration of steel projectiles into aluminum blocks and concrete slabs. The failure mode in the aluminum block is excessive deformation while the concrete slab fails by hole growth, spallation, and scabbing. The transient dynamic finite element code LS-DYNA2D was used fo… more
Date: May 1, 1994
Creator: Chen, E. P.
Partner: UNT Libraries Government Documents Department
open access

Risk management tools for the project designer

Description: Los Alamos National Laboratory uses a variety of continuous improvement methods, one of which is known as a Continuous Quality Improvement (CQI) Team. The CQI Teams and their results are proving to be effective in improving work processes at Los Alamos National Laboratory. The work reported in this paper is centered around the application of information systems to improve a LANL risk management process. The continuous improvement technique as well as its result should have applicability across … more
Date: May 1, 1994
Creator: Stuewe, R. B.; Barnes, M.; Brehm, D.; Rosenberg, D. & Jackson, K.
Partner: UNT Libraries Government Documents Department
open access

Next generation storage facility

Description: With diminishing requirements for plutonium, a substantial quantity of this material requires special handling and ultimately, long-term storage. To meet this objective, we at Los Alamos, have been involved in the design of a storage facility with the goal of providing storage capabilities for this and other nuclear materials. This paper presents preliminary basic design data, not for the structure and physical plant, but for the container and arrays which might be configured within the facilit… more
Date: May 1, 1994
Creator: Schlesser, J. A.
Partner: UNT Libraries Government Documents Department
open access

Comparative risk analysis for the Rocky Flats Plant integrated project planning

Description: The Rocky Flats Plant is developing, with active stakeholder a comprehensive planning strategy that will support transition of the Rocky Flats Plant from a nuclear weapons production facility to site cleanup and final disposition. Final disposition of the Rocky Flats Plant materials and contaminants requires consideration of the interrelated nature of sitewide problems, such as material movement and disposition, facility and land use endstates, costs relative risks to workers and the public, an… more
Date: May 1, 1994
Creator: Jones, M. E. & Shain, D. I.
Partner: UNT Libraries Government Documents Department
open access

Measurement of the asymmetry in the electro-disintegration of tensor polarized deuterons at the Novosibirsk VEPP-3 ring

Description: A series of experiments with an internal tensor polarized deuterium target in the 2 GeV VEPP-3 electron storage ring in Novosibirsk is being performed. This paper describes the first results for a measurement of the tensor asymmetry in the quasi-elastic (e, e{prime}p) reaction. The found results are compared to a non- relativistic calculation by Arenhoevel and Leidemann, including meson-exchange currents, isobar admixtures and final-state interactions.
Date: May 1, 1994
Creator: Theunissen, J. A. P.; de Jager, C. W. & van Leeuwe, J. J.
Partner: UNT Libraries Government Documents Department
open access

TIARA analysis of tritium inventory in Li{sub 2}O

Description: The TIARA code has been developed to predict tritium inventory in Li{sub 2}O breeder ceramic and to predict purge exit flow rate and composition under steady-state operating conditions. Inventory predictions are based on models for bulk diffusion, surface desorption, solubility and precipitation. Parameters for these models are determined from the results of laboratory annealing studies on unirradiated and irradiated Li{sub 2}O and from a limited number (2) of inventory data measured after in-r… more
Date: May 1, 1994
Creator: Billone, M. C.
Partner: UNT Libraries Government Documents Department
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Processing and testing ENDF/B-VI with NJOY and TRANSX

Description: The NJOY Nudear Data Processing System has been used to process the Evaluated Nuclear Data File ENDF/B-VI, including all changes through Release 2, into multigroup cross-section libraries that can be used with many different neutron/photon transport codes and into ACE format for use with the MCNP continuous-energy Monte Carlo code. The ENDF-6 format contains a number of new features of interest to reactor physics, and many of the new evaluations take advantage of these features to provided impr… more
Date: May 1, 1994
Creator: MacFarlane, R. E.
Partner: UNT Libraries Government Documents Department
open access

The development of laser ignited deflagration-to-detonation transition (DDT) detonators and pyrotechnic actuators

Description: The use of laser ignited explosive components has been recognized as a safety enhancement over existing electrical explosive devices (EEDs). Sandia has been pursuing the development of optical ordnance for many years with recent emphasis on developing optical deflagration-to-detonation (DDT) detonators and pyrotechnic actuators. These low energy optical ordnance devices can be ignited with either a semiconductor diode laser, laser diode arrays or a solid state rod laser. By using a semiconducto… more
Date: May 1, 1994
Creator: Merson, J. A. & Salas, F. J.
Partner: UNT Libraries Government Documents Department
open access

Computational analysis of azine-N-oxides as energetic materials

Description: A BKW equation of state in a 1-dimensional hydrodynamic simulation of the cylinder test can be used to estimate the performance of explosives. Using this approach, the novel explosive 1,4-diamino-2,3,5,6-tetrazine-2,5-dioxide (TZX) was analyzed. Despite a high detonation velocity and a predicted CJ pressure comparable to that of RDX, TZX performs relatively poorly in the cylinder test. Theoretical and computational analysis shows this to be the result of a low heat of detonation. A conceptual s… more
Date: May 1, 1994
Creator: Ritchie, J. P.
Partner: UNT Libraries Government Documents Department
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