Brillouin scattering from magnetic excitations in coupled layered systems and dots. (open access)

Brillouin scattering from magnetic excitations in coupled layered systems and dots.

None
Date: May 18, 1998
Creator: Grimsditch, M.
Object Type: Article
System: The UNT Digital Library
Characterization and durability testing of a glass-bonded ceramic waste form. (open access)

Characterization and durability testing of a glass-bonded ceramic waste form.

Argonne National Laboratory is developing a glass bonded ceramic waste form for encapsulating the fission products and transuranics from the conditioning of metallic reactor fuel. This waste form is currently being scaled to the multi-kilogram size for encapsulation of actual high level waste. This paper will present characterization and durability testing of the ceramic waste form. An emphasis on results from application of glass durability tests such as the Product Consistency Test and characterization methods such as X-ray diffraction and scanning electron microscopy. The information presented is based on a suite of tests utilized for assessing product quality during scale-up and parametric testing.
Date: May 18, 1998
Creator: Johnson, S. G.
Object Type: Article
System: The UNT Digital Library
The Congressional Budget Process Timetable (open access)

The Congressional Budget Process Timetable

The Congressional Budget Act (CBA) of 1974 (P.L. 93-344), as amended, establishes the congressional budget process, which coordinates the legislative activities on the budget resolution, appropriations bills, reconciliation legislation, revenue measures, and other budgetary legislation. Section 300 of this act provides a timetable (see Table 1) so that Congress may complete its work on the budget by the start of the fiscal year on October 1.
Date: May 18, 1998
Creator: Heniff, Bill, Jr.
Object Type: Report
System: The UNT Digital Library
Design and performance of a laser guide star system for the Keck II telescope (open access)

Design and performance of a laser guide star system for the Keck II telescope

A laser system to generate sodium-layer guide stars has been designed, built and delivered to the Keck Observatory in Hawaii. The system uses frequency doubled YAG lasers to pump liquid dye lasers and produces 20 W of average power. The design and performance results of this laser system are presented.
Date: May 18, 1998
Creator: Friedman, H. W., LLNL
Object Type: Article
System: The UNT Digital Library
Development of mixed-conducting ceramic membranes for hydrogen separation. (open access)

Development of mixed-conducting ceramic membranes for hydrogen separation.

SrCeO{sub 3}- and BaCeO{sub 3}-based proton conductors have been prepared and their transport properties have been investigated by impedance spectroscopy in conjunction with open circuit voltage and water vapor evolution measurements. BaCe{sub 0.8}Y{sub 0.2}O{sub 3-{delta}} exhibits the highest conductivity in a hydrogen-containing atmosphere; however, its electronic conductivity is not adequate for hydrogen separation in a nongalvanic mode. In an effort to enhance ambipolar conductivity and improve interfacial catalytic properties, BaCe{sub 0.8}Y{sub 0.2}O{sub 3-{delta}} cermets have been fabricated into membranes. The effects of ambipolar conductivity, membrane thickness, and interfacial resistance on permeation rates have been investigated. In particular, the significance of interfacial resistance is emphasized.
Date: May 18, 1998
Creator: Guan, J.
Object Type: Article
System: The UNT Digital Library
"Digital Era Copyright Enhancement Act": Analysis of H.R. 3048 (open access)

"Digital Era Copyright Enhancement Act": Analysis of H.R. 3048

None
Date: May 18, 1998
Creator: Shrader, Dorothy
Object Type: Report
System: The UNT Digital Library
Facility effluent monitoring plan for the tank farm facility (open access)

Facility effluent monitoring plan for the tank farm facility

A facility effluent monitoring plan is required by the US Department of Energy in DOE Order 5400.1 for any operations that involve hazardous materials and radioactive substances that could impact employee or public safety or the environment. This document is prepared using the specific guidelines identified in A Guide for Preparing Hanford Site Facility Effluent Monitoring Plans, WHC-EP-0438. This facility effluent monitoring plan assesses effluent monitoring systems and evaluates whether they are adequate to ensure the public health and safety as specified in applicable federal, state, and local requirements.
Date: May 18, 1998
Creator: Crummel, G. M.
Object Type: Report
System: The UNT Digital Library
A general kinetic-flow coupling model for FCC riser flow simulation. (open access)

A general kinetic-flow coupling model for FCC riser flow simulation.

A computational fluid dynamic (CFD) code has been developed for fluid catalytic cracking (FCC) riser flow simulation. Depending on the application of interest, a specific kinetic model is needed for the FCC flow simulation. This paper describes a method to determine a kinetic model based on limited pilot-scale test data. The kinetic model can then be used with the CFD code as a tool to investigate optimum operating condition ranges for a specific FCC unit.
Date: May 18, 1998
Creator: Chang, S. L.
Object Type: Article
System: The UNT Digital Library
Grouting guidelines for Hanford Tanks Initiative cone penetrometer borings (open access)

Grouting guidelines for Hanford Tanks Initiative cone penetrometer borings

Grouting of an open cone penetrometer (CP) borehole is done to construct a barrier that prevents the vertical migration of fluids and contaminants between geologic units and aquifers intersected by the boring. Whether to grout, the types of grout, and the method of deployment are functions of the site-specific conditions. This report recommends the strategy that should be followed both before and during HTI [Hanford Tanks Initiative] CP deployment to decide specific borehole grouting needs at Hanford SST farms. Topics discussed in this report that bear on this strategy include: Regulatory guidance, hydrogeologic conditions, operational factors, specific CP grouting deployment recommendations.
Date: May 18, 1998
Creator: Iwatate, D. F.
Object Type: Report
System: The UNT Digital Library
Indonesia: May 1998 Political Crisis and Implications for U.S. Policy (open access)

Indonesia: May 1998 Political Crisis and Implications for U.S. Policy

None
Date: May 18, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Indonesia: May 1998 Political Crisis and Implications for U.S. Policy (open access)

Indonesia: May 1998 Political Crisis and Implications for U.S. Policy

This report discusses the worsening political tensions in Indonesia that emerged as a result of discontent with policies enacted by President Suharto and his government, and the effects that these tensions have on US policy. The report cites the shooting of students by riot police, as well as rioting in Jakarta in May 1998 as another factor for the political unrest and uncertainty.
Date: May 18, 1998
Creator: Niksch, Larry A.
Object Type: Report
System: The UNT Digital Library
Irradiation creep of vanadium-base alloys. (open access)

Irradiation creep of vanadium-base alloys.

A study of irradiation creep in vanadium-base alloys is underway with experiments in the Advanced Test Reactor (ATR) and the High Flux Isotope Reactor (HFIR) in the US. Test specimens are thin-wall sealed tubes with internal pressure loading. The results from the initial ATR irradiation at low temperature (200-300 C) to a neutron damage level of 4.7 dpa show creep rates ranging from {approx}0 to 1.2 x 10{sup {minus}5}/dpa/MPa for a 500-kg heat of V-4Cr-4Ti alloy. These rates were generally lower than reported from a previous experiment in BR-10. Because both the attained neutron damage levels and the creep strains were low in the present study, however, these creep rates should be regarded as only preliminary. Substantially more testing is required before a data base on irradiation creep of vanadium alloys can be developed and used with confidence.
Date: May 18, 1998
Creator: Tsai, H.; Matsui, H.; Billone, M. C.; Strain, R. V. & Smith, D. L.
Object Type: Article
System: The UNT Digital Library
Kinematic performance analysis of a parallel-chain hexapod machine (open access)

Kinematic performance analysis of a parallel-chain hexapod machine

Inverse and forward kinematic models were derived to analyze the performance of a parallel-chain hexapod machine. Analytical models were constructed for both ideal and real structures. Performance assessment and enhancement algorithms were developed to determine the strut lengths for both ideal and real structures. The strut lengths determined from both cases can be used to analyze the effect of structural imperfections on machine performance. In an open-architecture control environment, strut length errors can be fed back to the controller to compensate for the displacement errors and thus improve the machine's accuracy in production.
Date: May 18, 1998
Creator: Song, Jing; Mou, Jong-I & King, Calvin
Object Type: Article
System: The UNT Digital Library
Mechanical properties and microstructural characteristics of laser and electron-beam welds in V-4Cr-4Ti. (open access)

Mechanical properties and microstructural characteristics of laser and electron-beam welds in V-4Cr-4Ti.

Mechanical properties and microstructural characteristics of laser and electron-beam welds of a 500-kg heat of V4Cr4Ti were investigated in as-welded condition and after postwelding heat treatment by impact testing, microhardness measurement, optical microscopy, X-ray diffraction, and transmission electron microscopy (TEM). Ductile-brittle transition temperatures of the laser and electron-beam welds were significantly higher than that of the base metal. However, excellent impact properties could be restored in both types of welds by postwelding annealing at 1000 C for 1 h in vacuum. Analysis by TEM revealed that annealed weld zones were characterized by extensive networks of fine V(C,O,N) precipitates, which clean away O, C, and N interstitial from the grain matrices. This process is accompanied by simultaneous annealing-out of the dense dislocations present in the weld zone. This finding could be useful in identifying an optimal welding procedure by controlling and adjusting the cooling rate of the weld zone by an innovative method to maximize the precipitation of V(C,O,N).
Date: May 18, 1998
Creator: Chung, H. M.
Object Type: Article
System: The UNT Digital Library
Metal waste forms from treatment of EBR-II spent fuel. (open access)

Metal waste forms from treatment of EBR-II spent fuel.

Demonstration of Argonne National Laboratory's electrometallurgical treatment of spent nuclear fuel is currently being conducted on irradiated, metallic driver fuel and blanket fuel elements from the Experimental Breeder Reactor-II (EBR-II) in Idaho. The residual metallic material from the electrometallurgical treatment process is consolidated into an ingot, the metal waste form (MWF), by employing an induction furnace in a hot cell. Scanning electron microscopy (SEM) and chemical analyses have been performed on irradiated cladding hulls from the driver fuel, and on samples from the alloy ingots. This paper presents the microstructures of the radioactive ingots and compares them with observations on simulated waste forms prepared using non-irradiated material. These simulated waste forms have the baseline composition of stainless steel - 15 wt % zirconium (SS-15Zr). Additions of noble metal elements, which serve as surrogates for fission products, and actinides are made to that baseline composition. The partitioning of noble metal and actinide elements into alloy phases and the role of zirconium for incorporating these elements is discussed in this paper.
Date: May 18, 1998
Creator: Abraham, D. P.
Object Type: Article
System: The UNT Digital Library
Neutron beam characterization at the Intense Pulsed Neutron Source. (open access)

Neutron beam characterization at the Intense Pulsed Neutron Source.

The Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory is a spallation neutron source dedicated to materials research. Its three cryogenic methane moderators provide twelve neutron beams to fourteen neutron scattering instruments and test facilities. The moderators at IPNS are of cryogenic methane (CH{sub 4}); one of liquid methane at 100 K, and two of solid methane at 30 K. These moderators produce intense beams of both cold and thermal neutrons. The moderators are each of a different physical configuration in order to tailor their performance for the instruments and facilities that operate on the neutron beams. As part of the ongoing operation of IPNS, as well as new enhancements to the target, moderator, and reflector systems, we have performed experiments characterizing the energy and time distribution of neutrons in the various beams. These measurements provide absolutely normalized energy spectra using foil activation techniques joined with time-of-flight measurements, and energy-dependent time distributions using a time-focused crystal analyzer. The IPNS accelerator system delivers 14 {micro}A of 450 MeV protons, in 100 ns pulses at 30 Hz, to a target composed of water-cooled depleted uranium disks. The solid methane ''H'' moderator is 100 by 100 by 45 mm in size, centerline …
Date: May 18, 1998
Creator: Iverson, E. B.
Object Type: Article
System: The UNT Digital Library
Performance of V-4Cr-4Ti material exposed to the DIII-D Tokamak environment. (open access)

Performance of V-4Cr-4Ti material exposed to the DIII-D Tokamak environment.

A series of tests is being conducted in the DIII-D tokamak to determine the effects of environmental exposure on a V-4Cr-4Ti vanadium alloy. These tests are part of the effort to build and install a water-cooled vanadium alloy structure in the DIII-D radiative diverter upgrade. Data from the test series indicate that the performance of the V-4Cr4Ti alloy would not be significantly affected by environmental exposure. Interstitial absorption by the material appears to be limited to the surface, and neither the tensile nor the impact properties of the material appear to be affected by the exposure.
Date: May 18, 1998
Creator: Tsai, H.; Smith, D. L.; Chung, H. M.; Johnson, W. R.; Smith, J. P. & Wampler, W. R.
Object Type: Article
System: The UNT Digital Library
Phenomenology and cosmology of weakly coupled string theory (open access)

Phenomenology and cosmology of weakly coupled string theory

The weakly coupled vacuum of E{sub 8} {circle_times} E{sub 8} heterotic string theory remains an attractive scenario for phenomenology and cosmology. The particle spectrum is reviewed and the issues of gauge coupling unification, dilaton stabilization and modular cosmology are discussed. A specific model for condensation and supersymmetry breaking, that respects known constraints from string theory and is phenomenologically viable, is described.
Date: May 18, 1998
Creator: Gaillard, Mary K.
Object Type: Article
System: The UNT Digital Library
Practical superconductor development for electrical power applications - quarterly report for the period ending March 31, 1998 1997. (open access)

Practical superconductor development for electrical power applications - quarterly report for the period ending March 31, 1998 1997.

This is a multiyear experimental research program focused on improving relevant material properties of high-T{sub c} superconductors and on development of fabrication methods that can be transferred to industry for production of commercial conductors. The development of teaming relationships through agreements with industrial partners is a key element of this program. Recent work on microstructural development and current distribution in Bi-2223 powder-in-tube (PIT) tapes, grain-boundary studies, and a novel application for high-temperature (high-T{sub c}) superconductors are discussed.
Date: May 18, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Pressure enhanced penetration with shaped charge perforators (open access)

Pressure enhanced penetration with shaped charge perforators

Computational analysis demonstrates that the penetration of a shaped charge jet can be enhanced by at least 25% by imploding the liner in a high pressure light gas atmosphere. The gas pressure helps confine the jet on the axis of penetration in the latter stages of formation. A light gas, such as helium or hydrogen, is required in order to keep the gas density low enough so as not to inhibit liner collapse.
Date: May 18, 1998
Creator: Glenn, L. A.
Object Type: Article
System: The UNT Digital Library
Revenue Legislation in the Congressional Budget Process (open access)

Revenue Legislation in the Congressional Budget Process

Most of the laws establishing the federal government's revenue sources are permanent and continue year after year without any additional legislative action. Congress, however, typically enacts revenue legislation, changing some portion of the existing tax system, every year. Revenue legislation may include changes to individual and corporate income taxes, social insurance taxes, excise taxes, or tariffs and duties. Congressional consideration of revenue legislation is governed by various constitutional provisions and procedural rules.
Date: May 18, 1998
Creator: Heniff, Bill, Jr.
Object Type: Report
System: The UNT Digital Library
SEVERAL TOUGH2 MODULES DEVELOPED FOR SITE CHARACTERIZATION STUDIES OF YUCCA MOUNTAIN (open access)

SEVERAL TOUGH2 MODULES DEVELOPED FOR SITE CHARACTERIZATION STUDIES OF YUCCA MOUNTAIN

None
Date: May 18, 1998
Creator: PRUESS, YU-SHU WU AND KARSTEN
Object Type: Report
System: The UNT Digital Library
Stable and Vibrational Octupole Modes in Mo, Xe, Ba, La, Ce and Nd (open access)

Stable and Vibrational Octupole Modes in Mo, Xe, Ba, La, Ce and Nd

Evidence is presented for stable octupole deformation in neutron-rich nuclei, bounded by Z = 54-58 and N = 85-92. To either side of this region negative parity bands built on more vibrational type octupole modes are observed in {sup 140}Ba and {sup 152,154}Nd. The largest stable octupole deformation ({beta}{sub s} {approximately} 0.1) is found in {sup 144}Ba{sub as}. The theoretically predicted quenching ({beta}{sub s} {approximately} 0) of stable octupole deformation at higher spins is found in {sup 140}Ba. There is good agreement between theory and experiment for the strongly varying electric dipole moments as a function of mass for {sup 142-141}Ba. In odd-A {sup 142}Ba and odd-Z {sup 140}La, we observe parity doublets, two pairs of positive and negative parity bands with opposite spins. In {sup 145}La a strong coupled ground band with symmetric shape coexists with the asymmetric octupole shape which stabilizes above about spin 19/2. In {sup 145,147}La a strong reduction in E2 strength around 25/2 from band crossing is observed. The isotope {sup 109}Mo was identified and a new region of stable uctpole deformation is identified in {sup 107,108}Mo centered around N = 64-66 as earlier predicted. This is the first case of stable uctpole deformation involving …
Date: May 18, 1998
Creator: Gore, P. M.; Hamilton, J. H.; Hwang, J. K.; Jones, E. F.; Peker, L. K.; Ramayya, A. V. et al.
Object Type: Article
System: The UNT Digital Library
Structure and property relationship in the mixed-conducting Sr-Fe-Co-O system. (open access)

Structure and property relationship in the mixed-conducting Sr-Fe-Co-O system.

Mixed-conducting ceramic oxides have potential uses in high-temperature electrochemical applications such as solid oxide fuel cells, advanced batteries, sensors, and oxygen-permeable membranes. The Sr-Fe-Co-O system combines high electronic/ionic conductivity with appreciable oxygen permeability at elevated temperatures. Dense ceramic membranes made of this material can be used to separate high-purity oxygen from air without the need for external electrical circuitry, or to partially oxidize methane to produce syngas. Samples of Sr{sub 2}Fe{sub 3{minus}x}Co{sub x}O{sub y} (with x = 0, 0.6, 1.0, and 1.4) were prepared by solid-state reaction in atmospheres with various oxygen partial pressures (pO{sub 2}) and were characterized by X-ray diffraction, scanning electron microscopy, and electrical conductivity measurements. Phase components of the samples are dependent on cobalt concentration and synthesis pO{sub 2}. Total conductivity increases with increasing temperature and cobalt content in the material. Higher ionic transference numbers have been observed in samples with lower cobalt contents. Current-voltage characteristics determined in a gas-tight cell indicate that a bulk effect, rather than a surface exchange effect, is the main limiting factor for oxygen permeation through membranes made of Sr{sub 2}Fe{sub 2}CoO{sub y}. Oxygen permeability measurements at various temperatures showed that oxygen permeability increases with increasing temperature, as expected. At 900 …
Date: May 18, 1998
Creator: Ma, B.
Object Type: Article
System: The UNT Digital Library