Motion-Dependent Fluid Forces Acting on Tube Arrays in Crossflow (open access)

Motion-Dependent Fluid Forces Acting on Tube Arrays in Crossflow

Motion-dependent fluids forces acting on a tube array were measured as a function of excitation frequency, excitation amplitude, and flow velocity. Fluid-damping and fluid-stiffness coefficients were obtained from measured motion-dependent fluid forces as a function of reduced flow velocity and excitation amplitude. The water channel and test setup provide a sound facility for obtaining key coefficients for fluid-elastic instability of tube arrays in crossflow. Once the guideline, based on the unsteady flow theory, can be developed for fluid-elastic instability of tube arrays crossflow.
Date: June 1993
Creator: Chen, Shoei-Sheng; Zhu, S. & Jendrzejczyk, J. A.
Object Type: Report
System: The UNT Digital Library
Experiment on Fluidelastic Instability of Loosely Supported Tube Arrays in Crossflow (open access)

Experiment on Fluidelastic Instability of Loosely Supported Tube Arrays in Crossflow

A tube array supported by baffle plates in crossflow may be subjected to fluid-elastic instability in the tube-support-plate-inactive mode. An experimental study is presented to characterize the tube motion. Three series of tests were performed to measure tube displacements as a function of flow velocity for different clearances. The motion was examined by root-mean-square values of tube displacements, power spectral densities, phase planes, Poincare maps, and Lyapunov exponents. The experimental data agree reasonably well with the analytical model, based on the unsteady flow theory.
Date: June 1993
Creator: Chen, Shoei-Sheng; Zhu, S. & Cai, Y.
Object Type: Report
System: The UNT Digital Library
Users manual for the Chameleon Parallel Programming Tools (open access)

Users manual for the Chameleon Parallel Programming Tools

Message passing is a common method for writing programs for distributed-memory parallel computers. Unfortunately, the lack of a standard for message passing has hampered the construction of portable and efficient parallel programs. In an attempt to remedy this problem, a number of groups have developed their own message-passing systems, each with its own strengths and weaknesses. Chameleon is a second-generation system of this type. Rather than replacing these existing systems, Chameleon is meant to supplement them by providing a uniform way to access many of these systems. Chameleon`s goals are to (a) be very lightweight (low over-head), (b) be highly portable, and (c) help standardize program startup and the use of emerging message-passing operations such as collective operations on subsets of processors. Chameleon also provides a way to port programs written using PICL or Intel NX message passing to other systems, including collections of workstations. Chameleon is tracking the Message-Passing Interface (MPI) draft standard and will provide both an MPI implementation and an MPI transport layer. Chameleon provides support for heterogeneous computing by using p4 and PVM. Chameleon`s support for homogeneous computing includes the portable libraries p4, PICL, and PVM and vendor-specific implementation for Intel NX, IBM EUI (SP-1), and …
Date: June 1993
Creator: Gropp, William & Smith, Barry
Object Type: Report
System: The UNT Digital Library
Preliminary Plan for Treating Mixed Waste (open access)

Preliminary Plan for Treating Mixed Waste

A preliminary waste treatment plan was developed for disposing of radioactive inorganic liquid wastes that contain hazardous metals and/or hazardous acid concentrations at Argonne National Laboratory. This plan, which involves neutralization and sulfide precipitation followed by filtration, reduces the concentration of hazardous metals and the acidity so that the filtrate liquid is simply a low-level radioactive waste that can be fed to a low-level waste evaporator.
Date: June 1993
Creator: Vandegrift, G. F.; Conner, C.; Hutter, Joseph C.; Leonard, R. A.; Nuñez, Luis; Sedlet, J. et al.
Object Type: Report
System: The UNT Digital Library
Health Insurance: The Hawaii Experience (open access)

Health Insurance: The Hawaii Experience

This paper provides a detailed look at the State that is often considered a model for what States can do to help provide universal or near universal health insurance coverage for their residents. The paper discusses the history of health insurance provision in Hawaii, emphasizing two relatively recent State insurance laws: 1) the 1974 law that required employers to offer coverage to most of their employees, and 2) the 1989 law that provided a State subsidy for coverage of those individuals who fell in the gap between employment-based coverage and Medicaid coverage. The paper addresses the difficulties faced in evaluating the impact of Hawaii’s various attempts to provide coverage and access, and speaks to whether all or parts of Hawaii’s experience can be transferred to other States or to the Nation as a whole.
Date: June 1993
Creator: United States. Congress. Office of Technology Assessment.
Object Type: Report
System: The UNT Digital Library
Who Goes There: Friend or Foe? (open access)

Who Goes There: Friend or Foe?

This report discusses the problem of fratricide, or “friendly fire” casualties among combat units. The House Armed Services Committee requested that OTA assess the technology and techniques available to reduce this tragic loss of life.
Date: June 1993
Creator: United States. Congress. Office of Technology Assessment.
Object Type: Report
System: The UNT Digital Library
Advanced Network Technology (open access)

Advanced Network Technology

This background paper analyzes technologies for tomorrow’s information superhighways. Advanced networks will first be used to support scientists in their work, linking researchers to supercomputers, databases, and scientific instruments. The paper also describes six test networks that are being funded as part of the High Performance Computing and Communications Program.
Date: June 1993
Creator: United States. Congress. Office of Technology Assessment.
Object Type: Report
System: The UNT Digital Library
An Inconsistent Picture: A Compilation of Analyses of Economic Impacts of Competing Approaches to Health Care Reform by Experts and Stakeholders (open access)

An Inconsistent Picture: A Compilation of Analyses of Economic Impacts of Competing Approaches to Health Care Reform by Experts and Stakeholders

This report reviews numerous analyses of the economic impacts of the major approaches to health care reform addressed in this Report-Single Payer, Play-or-Pay, Individual Vouchers or Tax Credits, and Managed Competition and identifies some of the key issues and significant assumptions behind the estimates provided in these analyses.
Date: June 1993
Creator: United States. Congress. Office of Technology Assessment.
Object Type: Report
System: The UNT Digital Library
The 73rd Texas Legislature, Summary of Significant Legislation (open access)

The 73rd Texas Legislature, Summary of Significant Legislation

This document is comprised of five sections; an overview of major issues; a list of all enrolled bill; sunset legislation; constitutional amendments; and gubernatorial vetoes. The section listing enrolled bills has been expanded this year to include the author/sponsors, relating clauses, and effective dates of the bills." (Foreword).
Date: June 1993
Creator: Texas. Legislature. Senate. Research Center.
Object Type: Report
System: The Portal to Texas History
Pilot study risk assessment for selected problems at the Nevada Test Site (NTS) (open access)

Pilot study risk assessment for selected problems at the Nevada Test Site (NTS)

The Nevada Test Site (NTS) is located in southwestern Nevada, about 105 km (65 mi) northwest of the city of Las Vegas. A series of tests was conducted in the late 1950s and early 1960s at or near the NTS to study issues involving plutonium-bearing devices. These tests resulted in the dispersal of about 5 TBq of [sup 239,24O]Pu on the surficial soils at the test locations. Additionally, underground tests of nuclear weapons devices have been conducted at the NTS since late 1962; ground water beneath the NTS has been contaminated with radionuclides produced by these tests. These two important problems have been selected for assessment. Regarding the plutonium contamination, because the residual [sup 239]Pu decays slowly (half-life of 24,110 y), these sites could represent a long-term hazard if they are not remediated and if institutional controls are lost. To investigate the magnitude of the potential health risks for this no-remediation case, three basic exposure scenarios were defined that could bring individuals in contact with [sup 239,24O]Pu at the sites: (1) a resident living in a subdivision, (2) a resident farmer, and (3) a worker at a commercial facility -- all located at a test site. The predicted cancer risks …
Date: June 1, 1993
Creator: Daniels, J.I. (ed.)
Object Type: Report
System: The UNT Digital Library
Determination of the energy of suprathermal electrons during lower hybrid current drive on PBX-M (open access)

Determination of the energy of suprathermal electrons during lower hybrid current drive on PBX-M

Suprathermal electrons are diagnosed by a hard x-ray pinhole camera during lower hybrid current drive on PBX-M. The experimental hard x-ray images are compared with simulated images, which result from an integration of the relativistic bremsstrahlung along lines-of-sight through the bean-shaped plasma. Images with centrally peaked and radially hollow radiation profiles are easily distinguished. The energy distribution of the suprathermal electrons is analyzed by comparing images taken with different absorber foils. An effective photon temperature is derived from the experimental images, and a comparison with simulated photon temperatures yields the energy of the suprathermal electrons. The analysis indicates that the energy of the suprathermal electrons in the hollow discharges is in the 50 to 100 key range in the center of the discharge. There seems to exist a very small higher energy component close to the plasma edge.
Date: June 1, 1993
Creator: Von Goeler, S.; Bernabei, S.; Davis, W.; Ignat, D.; Kaita, R.; Roney, P. et al.
Object Type: Article
System: The UNT Digital Library
Recovery and purification of nickel-63 from HFIR-irradiated targets (open access)

Recovery and purification of nickel-63 from HFIR-irradiated targets

The production of large quantities of high-specific-activity [sup 63]Ni (>10 Ci/g) requires both a highly enriched [sup 62]Ni target and a long irradiation period at high neutron flux. Trace impurities in the nickel and associated target materials are also activated and account for a significant fraction of the discharged activity and essentially all of the gamma activity. While most of these undesirable activation products can be removed as chloride complexes during anion exchange, chromium, present at [sup 51]Cr, and scandium, present as [sup 46]Sc, are exceptions and require additional processing to achieve the desired purity. Optimized flowsheets are discussed based upon the current development and production experience.
Date: June 1, 1993
Creator: Williams, D. F.; O'Kelley, G. D.; Knauer, J. B.; Porter, C. E. & Wiggins, J. T.
Object Type: Report
System: The UNT Digital Library
Digital control systems in nuclear power plants: Failure information, modeling concepts, and applications (open access)

Digital control systems in nuclear power plants: Failure information, modeling concepts, and applications

This report briefly describes some current applications of advanced computerized digital display and control systems at US commercial nuclear power plants and presents the results of a literature search that was made to gather information on the reliability of these systems. Both hardware and software reliability were addressed in this review. Only limited failure rate information was found, with the chemical process industry being the primary source of information on hardware failure rates and expert opinion the primary source for software failure rates. Safety-grade digital control systems are typically installed on a functional like-for-like basis, replacing older analog systems without substantially changing interactions with other plant systems. Future work includes performing a limited probabilistic risk assessment of a representative DCS to assess its risk significance.
Date: June 23, 1993
Creator: Galyean, W.J.
Object Type: Report
System: The UNT Digital Library
Pacific Northwest Laboratory Annual Report for 1992 to the DOE Office of Energy Research (open access)

Pacific Northwest Laboratory Annual Report for 1992 to the DOE Office of Energy Research

This report summarizes progress in OHER biological research and general life sciences research programs conducted at PNL in FY 1992. The research develops the knowledge and fundamental principles necessary to identify, understand, and anticipate the long-term health consequences of energy-related radiation and chemicals. Our continuing emphasis is to decrease the uncertainty of health risk estimates from energy-related technologies through an increase understanding of the ways in which radiation and chemicals cause biological damage. Descriptors of individual research projects as detailed in this report one separately abstracted and indexed for the database.
Date: June 1, 1993
Creator: Kreml, S. A. (ed.) & Park, J. F.
Object Type: Report
System: The UNT Digital Library
Computation and graphics in mathematical research (open access)

Computation and graphics in mathematical research

Current research is described on: grain boundaries and dislocations in compound polymers, boundary value problems for hypersurfaces constant Gaussian curvature, and discrete computational geometry. 19 refs, 4 figs.
Date: June 1, 1993
Creator: Hoffman, D.A. & Spruck, J.
Object Type: Report
System: The UNT Digital Library
The European nuclear power industry: Restructuring for combined strength and worldwide leadership (open access)

The European nuclear power industry: Restructuring for combined strength and worldwide leadership

The European nuclear power industry is being restructured from an industry drawn along national lines to a European-wide industry. This, in part, reflects growth of the European Economic Community, but it also reflects changes in the international nuclear power industry. The objectives of the participants, beyond better integration of the nuclear industry in Western Europe, are to (1) obtain European leadership of the worldwide commercial nuclear power industry, (2) improve medium- and long-term safety of Eastern Europe and the former Soviet Union (FSU) power reactors, and (3) reduce domestic concerns about nuclear power. The activities to achieve these goals include (1) formation of Nuclear Power International (a joint venture of the German and French nuclear power plant vendors for design and construction of nuclear power plants), (2) formation of a utility group to forge agreement throughout Europe on what the requirements are for the next generation of nuclear power plants, and (3) agreement by regulators in multiple European countries to harmonize regulations. This is to be achieved before the end of the decade. These changes would allow a single design of nuclear power plant to be built anywhere in Europe. The creation of European-wide rules (utility requirements, engineering standards, and …
Date: June 18, 1993
Creator: Forsberg, C.W.; Norman, R.E.; Reich, W.J. & Hill, L.J.
Object Type: Report
System: The UNT Digital Library
Conical geometry for sagittal focusing as applied to X rays from synchrotrons (open access)

Conical geometry for sagittal focusing as applied to X rays from synchrotrons

The authors describe a method for simultaneously focusing and monochromatization of X rays from a fan of radiation having up to 15 mrad divergence in one dimension. This geometry is well suited to synchrotron radiation sources at magnifications of one-fifth to two and is efficient for X-ray energies between 3 and 40 keV (0.48 and 6.4 fJ). The method uses crystals bent to part of a cone for sagittal focusing and allows for the collection of a larger divergence with less mixing of the horizontal into the vertical divergence than is possible with X-ray mirrors. They describe the geometry required to achieve the highest efficiency when a conical crystal follows a flat crystal in a nondispersive two-crystal monochromator. At a magnification of one-third, the geometry is identical to a cylindrical focusing design described previously. A simple theoretical calculation is shown to agree well with ray-tracing results. Minimum aberrations are observed at magnifications near one. Applications of the conical focusing geometry to existing and future synchrotron radiation facilities are discussed.
Date: June 1, 1993
Creator: Ice, G. E. & Sparks, C. J.
Object Type: Report
System: The UNT Digital Library
Dynamic impact and pressure analysis of the insensitive munitions container PA103 with modified design features (open access)

Dynamic impact and pressure analysis of the insensitive munitions container PA103 with modified design features

This report presents analytical analyses of the insensitive munitions container PA103, with modified design features for a static internal pressure of 500 psi and for a dynamic impact resulting from a 7-ft free fall onto a rigid surface. The modified design features addressed by the analyses were the inclusion of a score pattern on the container cylindrical body and a plastic plate (fuse) sandwiched between metal flanges on the container end. The objectives of both the pressure and impact analyses were to determine if the induced stresses at the score patterns in the cylindrical body of the container were sufficient to induce failure. Analytical responses of the container to the imposed loads were obtained with finite element analysis methodology. The computer codes ABAQUS and VEC/DYNA3D were used to obtain the results. Results of the pressure analysis indicate that failure of the container body would be expected to occur at the score pattern for a static internal pressure of 500 psi. Also, results from three impact orientations for a 7-ft drop indicate that membrane stresses in the vicinity of the score pattern are above critical crack growth stress magnitudes, especially at low ([minus]60[degrees]F) temperatures.
Date: June 1, 1993
Creator: Handy, K.D.
Object Type: Report
System: The UNT Digital Library
Measurements of the total CO[sub 2] concentration and partial pressure of CO[sub 2] in seawater during WOCE expeditions in the South Pacific Ocean (open access)

Measurements of the total CO[sub 2] concentration and partial pressure of CO[sub 2] in seawater during WOCE expeditions in the South Pacific Ocean

During the first year of the grant, we participated in three WOCE expeditions (a total of 152 days at sea) in the South Pacific Ocean, and the field phase of the proposed investigation has been successfully completed. The total CO[sub 2] concentration and pCO[sub 2] were determined at sea in 4419 water samples collected at 422 stations. On the basis of the shipboard analyses of SIO Reference Solutions for CO, and a comparison with the results of previous expeditions, the overall precision of our total CO[sub 2] determinations is estimated to be about [plus minus]2 uM/kg. The deep water data indicate that there is a CO[sub 2] maximum centered about 2600 meters deep. This appears to represent a southward return flow from the North Pacific. The magnitude and distribution of the CO, maximum observed along the 135.0[degrees]W meridian differ from those observed along the 150.5[degrees]W meridian due to Tuamotu Archipelago, a topographic high which interferes with the southward return flow. The surface water pCO[sub 2] data indicate that the South Pacific sub-tropical gyre water located between about 15[degrees]S and 50[degrees]S is a sink for atmospheric CO[sub 2].
Date: June 29, 1993
Creator: Takahashi, T.; Goddard, J. G.; Chipman, D. W. & Rubin, S. I.
Object Type: Report
System: The UNT Digital Library
NREL Solar Radiation Resource Assessment Project: Status and Outlook, FY 1992 Annual Progress Report (open access)

NREL Solar Radiation Resource Assessment Project: Status and Outlook, FY 1992 Annual Progress Report

This annual report summaries the activities and accomplishments of the Solar Radiation Resource Assessment Project during fiscal year 1992 (1 October to 30 September 1992). Managed by the Analytic Studies Division of the National Renewable Energy Laboratory, this project is the major activity of the US Department of Energy's Resource Assessment Program.
Date: June 1, 1993
Creator: Renne, D.; Maxwell, E.; Stoffel, T.; Marion, B.; Rymes, M.; Wilcox, S. et al.
Object Type: Report
System: The UNT Digital Library
The three-point function as a probe of models for large-scale structure (open access)

The three-point function as a probe of models for large-scale structure

The authors analyze the consequences of models of structure formation for higher-order (n-point) galaxy correlation functions in the mildly non-linear regime. Several variations of the standard [Omega] = 1 cold dark matter model with scale-invariant primordial perturbations have recently been introduced to obtain more power on large scales, R[sub p] [approximately]20 h[sup [minus]1] Mpc, e.g., low-matter-density (non-zero cosmological constant) models, [open quote]tilted[close quote] primordial spectra, and scenarios with a mixture of cold and hot dark matter. They also include models with an effective scale-dependent bias, such as the cooperative galaxy formation scenario of Bower, et al. The authors show that higher-order (n-point) galaxy correlation functions can provide a useful test of such models and can discriminate between models with true large-scale power in the density field and those where the galaxy power arises from scale-dependent bias: a bias with rapid scale-dependence leads to a dramatic decrease of the hierarchical amplitudes Q[sub J] at large scales, r [approx gt] R[sub p]. Current observational constraints on the three-point amplitudes Q[sub 3] and S[sub 3] can place limits on the bias parameter(s) and appear to disfavor, but not yet rule out, the hypothesis that scale-dependent bias is responsible for the extra power observed …
Date: June 19, 1993
Creator: Frieman, J.A. (Fermi National Accelerator Lab., Batavia, IL (United States)) & Gaztanaga, E. (Univ. of Oxford (United Kingdom))
Object Type: Report
System: The UNT Digital Library
Performance of production SRF cavities for CEBAF (open access)

Performance of production SRF cavities for CEBAF

Construction of the Continuous Electron Beam Accelerator Facility recirculating linac represents the largest scale application of superconducting rf (SRF) technology to date. Over 250 of the eventual 338 SRF 1497 MHz cavities have been assembled into hermetic pairs and completed rf testing at 2.0 K. Although the rf performance characteristics well exceed the CEBAF baseline requirements of Q[sub 0] = 2.4[times]10[sup 9] at 5 MV/m, the usual limiting phenomena are encountered field emission, quenching, Q-switching, will occasional multipacting. An analysis of the occurrence conditions and severity of these phenomena during production cavity testing is presented. The frequency with which performance is limited by quenching suggests that additional material advances may be required for applications which require the reliable achievement of accelerating gradients of more than 15 MV/m. The distributions of frequency and Q for a higher-order mode are also presented.
Date: June 1, 1993
Creator: Reece, C.; Benesch, J.; Kneisel, P.; Kushnick, P.; Mammosser, J. & Powers, T.
Object Type: Article
System: The UNT Digital Library
Macro material flow modeling for analyzing solid waste management options (open access)

Macro material flow modeling for analyzing solid waste management options

A Macro Material Flow Modeling (MMFM) concept and approach are being adopted to develop a predictive modeling capability. This capability is intended to provide part of the basis for evaluating potential impacts from various solid waste management system configurations and operating scenarios, as well as evaluating the impacts of various policies on solid waste quantities and compositions. The MMFM capability, as part of a broader Solid Waste Initiative at Pacific Northwest Laboratory, is intended to provide an increased understanding of solid waste as a disposal, energy, and resource problem on a national and global scale, particularly over the long term. This model is a macro-level simulation of the flows of the various materials through the solid waste management system, and also through the associated materials production and use system. Inclusion of materials production and use within the modeling context allows a systems approach to be used, providing a much more complete understanding of the origins of the solid waste materials and also of possible options for materials recovery and reuse than if a more traditional end-of-pipe'' view of solid waste is adopted. The MMFM is expected to be useful in evaluating longer-term, broader-ranging solid waste impacts than are traditionally evaluated …
Date: June 1, 1993
Creator: Holter, G. M.; Pennock, K. A. & Shaver, S. R.
Object Type: Article
System: The UNT Digital Library
Characterization of nanoscale oxide and oxyhydroxide powders using EXAFS spectroscopy (open access)

Characterization of nanoscale oxide and oxyhydroxide powders using EXAFS spectroscopy

Extended x-ray absorption fine structure (EXAFS) spectroscopy has been used to determine the structural environment local to iron(HI) and zircorium(IV) cations in respectively, nanoscale iron oxyhydroxide and nanoscale zirconium oxide powders. The iron oxyhydroxide powder, produced by the modified reverse micelle (MRM) technology, was found to have a short-range structure most similar to that of goethite ([alpha]-FeOOH). The short-range structure of the zirconium oxide powder, produced using the rapid thermal decomposition of solutes (RTDS) technology, was found to be a mixture of monoclinic zirconia and cubic zirconia environments.
Date: June 1, 1993
Creator: Darab, J.G.; Linehan, J.C.; Matson, D.W. (Pacific Northwest Lab., Richland, WA (United States)) & Ma, Y. (Washington Univ., Seattle, WA (United States). Dept. of Physics)
Object Type: Article
System: The UNT Digital Library