468 Matching Results

Search Results

Results: 1 - 24 next
open access

MLE (Maximum Likelihood Estimator) reconstruction of a brain phantom using a Monte Carlo transition matrix and a statistical stopping rule

Description: In order to study properties of the Maximum Likelihood Estimator (MLE) algorithm for image reconstruction in Positron Emission Tomographyy (PET), the algorithm is applied to data obtained by the ECAT-III tomograph from a brain phantom. The procedure for subtracting accidental coincidences from the data stream generated by this physical phantom is such that he resultant data are not Poisson distributed. This makes the present investigation different from other investigations based on computer-si… more
Date: October 1, 1987
Creator: Veklerov, E.; Llacer, J. & Hoffman, E.J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

MTX (Microwave Tokamak Experiment) facility and machine grounding plan

Description: A key issue in the design of fusion research experiments and their related facilities is the control of ground currents. Because of the large magnetic field, high voltages and high currents present in most of these installations, it is essential to avoid ground loops, and to control ground currents during both normal operations and fault conditions. This paper describes the grounding policy that was developed for MTX. The vault area was divided into zones, and each of the four walls was treated… more
Date: October 7, 1987
Creator: Bell, H.H.; Rice, B.W.; Petersen, D.E. & Herrera, C.H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Magnet power system for the Microwave Tokamak Experiment (MTX)

Description: The system configuration, layout, and general philosophy for the MTX magnet power system is described. The vast majority of the magnet power equipment was quite successfully used on the ALCATOR-C experiment at the Massachusetts Institute of Technology. The AC power for the magnet system at MIT was obtained from a 225MVA alternator. The power for the system at LLNL is obtained directly from the local utility's 230 kV line. This installation, therefore, necessitates the addition of a great deal o… more
Date: October 7, 1987
Creator: Jackson, M.C. & Musslewhite, R.C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The effects of halides on the performance of coal gas-fueled molten carbonate fuel cells: Final report, October 1986-October 1987

Description: This report presents the results of a program to determine the probable tolerable limits of hydrogen chloride and hydrogen fluoride present in the fuel and oxidant streams of molten carbonate fuel cells that are operating on gasified coal. A literature survey and thermodynamic analyses were performed to determine the likely effects of halides on cell performance and materials. Based on the results of these studies, accelerated corrosion experiments and electrode half-cell performance tests were… more
Date: October 1, 1987
Creator: Magee, T. P.; Kunz, H. R.; Krasij, M. & Cote, H. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Combustion of ultrafine coal/water mixtures and their application in gas turbines: Final report

Description: The feasibility of using coal-water fuels (CWF) in gas turbine combustors has been demonstrated in recent pilot plant experiments. The demands of burning coal-water fuels with high flame stability, complete combustion, low NO/sub x/ emission and a resulting fly ash particle size that will not erode turbine blades represent a significant challenge to combustion scientists and engineers. The satisfactory solution of these problems requires that the variation of the structure of CWF flames, i.e., … more
Date: October 1, 1987
Creator: Toqan, M.A.; Srinivasachar, S.; Staudt, J.; Varela, F. & Beer, J.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

1987 Oak Ridge model conference: Proceedings

Description: A conference sponsored by the United States Department of Energy (DOE), was held on waste management. Topics included waste management, site remediation, waste minimization, economic and social aspects of waste management, and waste management training. Several case studies of US DOE facilities are included. Individual projects are processed separately for the data bases. (CBS)
Date: October 1, 1987
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

An overview of the IAEA Safety Series on procedures for evaluating the reliability of predictions made by environmental transfer models

Description: The International Atomic Energy Agency is preparing a Safety Series publication on practical approaches for evaluating the reliability of the predictions made by environmental radiological assessment models. This publication identifies factors that affect the reliability of these predictions and discusses methods for quantifying uncertainty. Emphasis is placed on understanding the quantity of interest specified by the assessment question and distinguishing between stochastic variability and lac… more
Date: October 1, 1987
Creator: Hoffman, F. W. & Hofer, E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Aurora status and plans

Description: Aurora is a short wavelength (248 nm) 10 to kJ KrF laser systems in the ICF program at Los Alamos National Laboratory. It is both an experiment in driver technology and a means for studying target performance using KrF laser light. Both features will be used to help evaluate the uv excimer laser as a viable fusion driver. The system has been designed to employ several electron-beam pumped amplifiers in series, with a final aperture of one meter square, to amplify 96 angularly mulitplexed 5 ns b… more
Date: October 1, 1987
Creator: Kristal, R.; Blair, L. S.; Burrows, M. D.; Cartwright, D. C.; Goldstone, P. D.; Greene, D. P. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

Description: AMAX Research Development Center (AMAX R D) has been investigating methods for improving the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hog coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. The reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point in a bench-scale fixed-bed reactor. The durability may… more
Date: October 27, 1987
Creator: Jha, M. C. & Berggren, M. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Reanalysis of Zion risk

Description: As part of the NUREG-1150 efforts, Brookhaven National Laboratory (BNL) has undertaken a risk analysis of Zion Unit 1 adopting the methodology developed at Sandia National Laboratories (SNL) under the Severe Accident Risk Rebaselining Program. Results of the preliminary version of the analysis are reported here. Completion plans for the Zion study are described also.
Date: October 1, 1987
Creator: Park, C.K.; Unwin, S.D.; Cazzoli, E.; Tingle, A. & Chun, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Portable Pbars, traps that travel

Description: The advent of antiproton research utilizing relatively small scale storage devices for very large numbers of these particles opens the possibility of transporting these devices to a research site removed from the accelerator center that produced the antiprotons. Such a portable source of antiprotons could open many new areas of research and make antiprotons available to a new research community. At present antiprotons are available at energies down to 1 MeV. From a portable source these particl… more
Date: October 1, 1987
Creator: Howe, S.D.; Hynes, M.V. & Picklesimer, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Solubility and superconductivity in RE(Ba sub 2-x RE sub x )Cu sub 3 O sub 7+. delta. (RE = Nd, Sm, Eu, Gd, Dy)

Description: Solid solutions of RE(Ba{sub 2-x}RE{sub x})Cu{sub 3}O{sub 7- {delta}}(RE=Nd,Sm,Eu,Gd,Dy) for x=0 to x=0.5 have been investigated. X-ray and resistivity measurements show that there exists a solid solution region, through which, the structure changes from orthorhombic to tetragonal and the superconducting properties are depressed. The solubility limits depend strongly on the size of the rare-earth ion, with the smallest (Dy) showing no appreciable solubility. The superconducting transition tempe… more
Date: October 1, 1987
Creator: Zhang, K.; Dabrowski, B.; Segre, C.U.; Hinks, D.G.; Schuller, I.K.; Jorgensen, J.D. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

[Letter from James R. Miller to Carl L. Yeckel, October 8, 1987]

Description: Letter from James R. Miller to Carl L. Yeckel, of the Carl B. and Florence E. King Foundation, on October 8, 1987, mentioning the recent visit of Julian C. Stanley to the university, and thanking Yeckel for his consideration of their proposal. Stanley's letter of thanks to Alfred Hurley is included.
Date: October 8, 1987
Creator: Miller, James R.
Item Type: Refine your search to only Letter
Partner: Texas Academy of Mathematics and Science
open access

[Letter from Valleau Wilkie, Jr. to James J. Muro, October 8, 1987]

Description: Letter from Valleau Wilkie, Jr. to James J. Muro, on October 8, 1987, informing him that Muro's request for a grant to North Texas State University for the Texas Academy of Mathematics and Science has been denied, although he promises that it will be revisited in early 1988.
Date: October 8, 1987
Creator: Wilkie, Valleau, Jr.
Item Type: Refine your search to only Letter
Partner: Texas Academy of Mathematics and Science
open access

A Review and Analysis of Fortran 8x

Description: The ANSI Standards Subcommittee X3J3 on Fortran has recently completed a draft proposed standard for the Fortran programming language. The draft proposed standard, known informally as Fortran 8x, is a revision of the current standard X3.9-1978, known informally as Fortran 77. This report is a review of Fortran 8x and consists of a series of six articles. The first article gives a general overview of Fortran 8x. The next three articles give brief discussions of the array facilities; the enhanced… more
Date: October 1987
Creator: Smith, Brian T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Application of a Multigrid Method to a Buoyancy-Induced Flow Problem

Description: The numerical prediction of buoyancy-induced flows provides special difficulties for standard numerical techniques associated with velocity-buoyancy coupling. We present a multigrid algorithm based upon a novel relaxation scheme that handles this coupling correctly. Numerical experiments have been performed that show that this approach is reasonably efficient and robust for a range of Rayleigh numbers and a variety of cycling strategies.
Date: October 1987
Creator: Thompson, C. P.; Leaf, G. K. & Vanka, S. P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Performance evaluation of PEP

Description: An investigation of collective effects has been undertaken to assess the possibilities for using the low emittance operating mode of the PEP storage ring as a dedicated source of synchrotron radiation. Beam current limitations associated with longitudinal and transverse instabilities, and the expected emittance growth due to intrabeam scattering have been studied as a function of beam energy. Calculations of the beam lifetime due to Touschek and gas scattering are presented, and the growth time… more
Date: October 1, 1987
Creator: Zisman, M. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Radioactivation in ''quiet'' sections of the SSC (Superconducting Super Collider)

Description: Estimation of induced radioactivity in the ''quiet'' sections of the SSC is approached using elementary methods. Estimates are given of total activity and residual dose rates on the surface of magnets in the quiet regions, as well as estimates of the activation of tunnel concrete. The residual radioactivity produced in the magnets and concrete walls of the ''quiet'' regions of the SSC are found to be quite small and of little radiological impact, but that simple scaling could yield results for … more
Date: October 1, 1987
Creator: Cossairt, J.D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Effect of experimental variables on flash thermal diffusivity data analysis

Description: Flash thermal diffusivity data are usually analyzed with a thermal model which assumes axial heat conduction and uniform illumination of the flashed surface. For high accuracy data reduction, it becomes important to bound to the errors caused by radial heat flow and by non-uniform laser beam profiles. These effects are examined analytically for a case in which the incident laser beam is confined to a radius smaller than the sample radius. The dependence of the output of an averaging detector on… more
Date: October 1, 1987
Creator: Sweet, J.N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

High-field superconducting solenoids for the TIBER II PF (poloidal-field) system

Description: The poloidal-field (PF) coil set for the Tokamak Ignition/Burn Engineering Reactor (TIBER-II) consists of 24 solenoid modules, 16 of which are stacked inside the toroidal-field (TF) system at the center of the machine. These central solenoid modules operate at high-current densities, and maximum fields at the windings approach 14 T. Although TIBER-II is designed for steady-state operation with noninductive current drive, other operating scenarios are also considered. In the pulsed or inductive … more
Date: October 7, 1987
Creator: Kerns, J. A.; Miller, J. R. & Summers, L. T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen