Serial/Series Title
Fiscal Year 1997
4
Chemical Processing Department Monthly Report
3
ARM Facilities Newsletter
2
Fiscal Year 1996
2
Fiscal Year 2007
2
Proceedings of RIKEN BNL Research Center Workshop
2
Winter Fuels Report
2
A Real-Time Coal Content/Ore Grade (C2OG) Sensor, Technical Report
1
Bench Scale Testing of Micronized Magnetite Beneficiation Progress Report
1
Cross-Roll Flow Forming of ODS Alloy Heat Exchanger Tubes For Hoop Creep Enhancement Quarterly Report
1
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Nuclear properties for astrophysical applications
We tabulate the ground-state odd-proton and odd-neutron spins, proton and neutron pairing gaps, binding energies, neuton separation energies, quantities related to {beta}-delayed one, two and three neutron emission probabilities, {beta}-decay Q values and half-lives with respect to Gamow-Teller decay, proton separation energies, and {alpha}-decay Q values and half-lives. The starting point of the calculations is a calculation of nuclear ground-states and (information based on the finite-range droplet model and the folded-Yukawa single-particle model published in a previous issue of ATOMIC DATA AND NUCLEAR DATA TABLES. The {beta}-delayed neutron-emission probabilities and Gamow-Teller {beta}-decay rates are obtained from a QRPA model that uses single-particle levels and wave-functions at the calculated nuclear ground-state shape as the starting point.
Date:
September 23, 1994
Creator:
Moeller, P.; Nix, J. R. & Kratz, K. L.
Object Type:
Report
System:
The UNT Digital Library
Physics results from polarized DIS.
We have extracted polarized nucleon distributions from recent data at CERN, SLAC and DESY. The flavor-dependent valence and sea quark spin distributions are determined for each experiment. We take into account possible differences in the up and down sea distributions, and assume that the strange sea contribution is suppressed by mass effects. Physics results determined from different experiments are compared, including higher order corrections.
Date:
March 23, 1998
Creator:
Ramsey, G. P.
Object Type:
Article
System:
The UNT Digital Library
Use of Simulation for the Programs for the Modeling of the Next Linear Collider
The Next Linear Collider is an electron-positron accelerator unprecedented in its size, energy, and tight tolerances. We describe the suite of simulation tools which are widely used in designing and modeling the performance of the NLC. In order to achieve a uniform beamline description and permit simulation of all facets of the collider, an extended version of the Standard Input Format (xSIF) has been developed and implemented in MAD and DIMAD. We discuss several enhancements to the MAD and DIMAD calculation engines necessary to properly simulate the most challenging regions of the facility. We also describe enhancements to LIAR which allow it to be used as the tracking engine for a tuning/feedback simulation written in MATLAB. Finally, we discuss the additional software needed to model the beam stabilization and tuning processes.
Date:
April 23, 1999
Creator:
Tenenbaum, Peter G
Object Type:
Report
System:
The UNT Digital Library
Solder Mounting Technologies for Electronic Packaging
Soldering provides a cost-effective means for attaching electronic packages to circuit boards using both small scale and large scale manufacturing processes. Soldering processes accommodate through-hole leaded components as well as surface mount packages, including the newer area array packages such as the Ball Grid Arrays (BGA), Chip Scale Packages (CSP), and Flip Chip Technology. The versatility of soldering is attributed to the variety of available solder alloy compositions, substrate material methodologies, and different manufacturing processes. For example, low melting temperature solders are used with temperature sensitive materials and components. On the other hand, higher melting temperature solders provide reliable interconnects for electronics used in high temperature service. Automated soldering techniques can support large-volume manufacturing processes, while providing high reliability electronic products at a reasonable cost.
Date:
September 23, 1999
Creator:
VIANCO, PAUL T.
Object Type:
Article
System:
The UNT Digital Library
The Use of Computerized Thermodynamics Databases for Solidification Modeling of Fusion Welds in Multi-Component Alloys
Most engineering alloys contain numerous alloying elements and their solidification behavior can not typically be modeled with existing binary and ternary phase diagrams. There has recently been considerable progress in the development of thermodynamic software programs for calculating solidification parameters and phase diagrams of multi-component systems. These routines can potentially provide useful input data that are needed in multi-component solidification models. However, these thermodynamic routines require validation before they can be confidently applied to simulations of alloys over a wide range of composition. In this article, a preliminary assessment of the accuracy of the Thermo-Calc NiFe Superalloy database is presented. The database validation is conducted by comparing calculated phase diagram quantities to experimental measurements available in the literature. Comparisons are provided in terms of calculated and measured liquidus and solidus temperatures and slopes, equilibrium distribution coefficients, and multi-component phase diagrams. Reasonable agreement is observed among the comparisons made to date. Examples are provided which illustrate how the database can be used to approximate the solidification sequence and final segregation patterns in multi-component alloys. An additional example of the coupling of calculated phase diagrams to solute redistribution computations in a commercial eight component Ni base superalloy is also presented.
Date:
September 23, 1999
Creator:
DUPONT,JOHN N.; KNOROVSKY,GERALD A.; NEWBURY,BRIAN D. & ROBINO,CHARLES V.
Object Type:
Article
System:
The UNT Digital Library
Tank waste remediation system fiscal year 1997 multi-year workplan WBS 1.1
The U.S. Department of Energy (DOE) established the Tank Waste Remediation System (TWRS) Program to manage and immobilize for disposal the waste contained in underground storage tanks at the Hanford Site. The TWRS program was established as a DOE major system acquisition under an approved Justification of Mission Need (JMN) dated January 19, 1993. The JMN states that the purpose of the TWRS Program is to: Resolve the tank waste safety issues; Integrate the waste disposal mission with the ongoing waste management mission; Assess the technical bases for tank waste management and disposal; Determine the technology available and develop any needed technologies; and Establish a dedicated organization and provide the resources to meet the technical challenge. The principal objectives of management of existing and future tank wastes is to cost-effectively minimize the environmental, safety, and health risks associated with stored wastes, with reduction of safety risks given the highest priority. The potentials must be minimized for release of tank wastes to the air and to the ground (and subsequently to the groundwater) and for exposure of the operating personnel to tank wastes.
Date:
September 23, 1996
Creator:
Wilson, C. E.
Object Type:
Report
System:
The UNT Digital Library
Microstructure and nonstoichiometry of barium strontium titanate thin films for dram applications.
In this paper we investigate the microstructural accommodation of nonstoichiometry in (Ba{sub x}Sr{sub 1{minus}x}Ti{sub 1+y}O{sub 3+z}) thin films grown by chemical vapor deposition. Films with three different (Ba+Sr)/Ti ratios of 49/51 (y=0.04 in the notation of the formula above), of 48/52 (y=0.08) and of 46.5/53.5 (y=O.15), were studied. High-resolution electron microscopy is used to study the microstructure of the BST films. High-spatial resolution electron energy-loss spectroscopy (EELS) is used to reveal changes in chemistry and local atomic environment both at grain boundaries and within grains as a function of titanium excess. We find an amorphous phase at the grain boundaries and grain boundary segregation of excess titanium in the samples with y=0.15. In addition, EELS is also used to show that excess titanium is being partially accommodated in the grain interior. Implications for the film electrical and dielectric properties are outlined.
Date:
April 23, 1999
Creator:
Browning, N. D.; Kingon, A. I.; Stemmer, S. & Streiffer, S. K.
Object Type:
Article
System:
The UNT Digital Library
Quantum Monte Carlo calculations for light nuclei.
Quantum Monte Carlo calculations of ground and low-lying excited states for nuclei with A {le} 8 are made using a realistic Hamiltonian that fits NN scattering data. Results for more than 40 different (J{pi}, T) states, plus isobaric analogs, are obtained and the known excitation spectra are reproduced reasonably well. Various density and momentum distributions and electromagnetic form factors and moments have also been computed. These are the first microscopic calculations that directly produce nuclear shell structure from realistic NN interactions.
Date:
October 23, 1998
Creator:
Wiringa, R. B.
Object Type:
Article
System:
The UNT Digital Library
{gamma}{gamma} {r_arrow} {gamma}{gamma} as a Test of Weak Scale Quantum Gravity at the NLC
Recently, it has been proposed that the fundamental scale of quantum gravity can be close to the weak scale if there are large extra dimensions . This proposal has important phenomenological implications for processes at the TeV scale. We study the process {gamma}{gamma} {r_arrow} {gamma}{gamma}, assuming an ultraviolet cutoff M{sub S} {approximately} 1 TeV for the effective gravity theory. We find that, at center of mass energies {radical}s {approximately} 1 TeV, the contribution of gravitationally mediated scattering to the cross section is comparable to that coming from the one-loop Feynman diagrams of the Standard Model. We thus conclude that the effects of weak scale quantum gravity can be studied at the Next Linear Collider (NLC), in the photon collider mode. Our results suggest that, for typical proposed NLC energies and luminosities, the range 1 TeV {le} M{sub S} {le} 10 TeV can be probed.
Date:
April 23, 1999
Creator:
Davoudiasl, Hooman
Object Type:
Report
System:
The UNT Digital Library
Calibration of seismic wave propagation in Jordan
The Natural Resources Authority of Jordan (NRA), the USGS and LLNL have a collaborative project to improve the calibration of seismic propagation in Jordan and surrounding regions. This project serves common goals of CTBT calibration and earthquake hazard assessment in the region. These objectives include accurate location of local and regional earthquakes, calibration of magnitude scales, and the development of local and regional propagation models. In the CTBT context, better propagation models and more accurately located events in the Dead Sea rift region can serve as (potentially GT5) calibration events for generating IMS location corrections. The detection and collection of mining explosions underpins discrimination research. The principal activity of this project is the deployment of two broadband stations at Hittiyah (south Jordan) and Ruweishid (east Jordan). These stations provide additional paths in the region to constrain structure with surface wave and body wave tomography. The Ruweishid station is favorably placed to provide constraints on Arabian platform structure. Waveform modeling with long-period observations of larger earthquakes will provide constraints on 1-D velocity models of the crust and upper mantle. Data from these stations combined with phase observations from the 26 short-period stations of the Jordan National Seismic Network (JNSN) may allow …
Date:
July 23, 1999
Creator:
Al-Husien, A.; Amrat, A.; Harris, D.; Mayeda, K.; Nakanishi, K.; Rodgers, A. et al.
Object Type:
Article
System:
The UNT Digital Library
Cylinder inspection logs and analytical data LCRU-001 through LCRU-063. Volume 3, Final report
ERC sampled, analyzed, and recontainerized when necessary gas cylinders of various chemicals in storage at LANL TA-54 Area L. This report summarizes the operation. This is Volume 3 of five volumes.
Date:
June 23, 1994
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Real Time Air Monitoring Using Open-Path FTIR
Over the last several years there has been renewed interest in the use of open-path Fourier Transform Infrared (FTIR) spectroscopy for a variety of air monitoring applications. The intersect has been motivated by the need for new technology to address the regulator requirements of the Clean Air Act Amendment of 1990. Interest has been expressed in exploring the applications of this technology to locate fugitive-source emissions and measuring total emissions from industrial facilities.
Date:
September 23, 1998
Creator:
Gamiles, D.S
Object Type:
Report
System:
The UNT Digital Library
Front-flash thermal imaging characterization of continuous fiber ceramic composites.
Infrared thermal imaging has become increasingly popular as a nondestructive evaluation method for characterizing materials and detecting defects. One technique, which was utilized in this study, is front-flash thermal imaging. We have developed a thermal imaging system that uses this technique to characterize advanced material systems, including continuous fiber ceramic composite (CFCC) components. In a front-flash test, pulsed heat energy is applied to the surface of a sample, and decay of the surface temperature is then measured by the thermal imaging system. CFCC samples with drilled flat-bottom holes at the back surface (to serve as ''flaws'') were examined. The surface-temperature/time relationship was analyzed to determine the depths of the flaws from the front surface of the CFCC material. Experimental results on carbon/carbon and CFCC samples are presented and discussed.
Date:
April 23, 1999
Creator:
Deemer, C.
Object Type:
Article
System:
The UNT Digital Library
Lithium intercalation in porous carbon anodes
Carbon foams derived from the phase separation of polyacrylonitrile/solvent mixtures were investigated as lithium intercalation anodes for rechargeable lithium-ion batteries. The carbon foams have a bulk density of 0.35--0.5 g/cm{sup 3}, low surface area (< 50 m{sup 2}/g), and an average cell size of 5--10 {mu}m. Polyacrylonitrile-based carbon foams doped with phosphoric acid had capacity as high as 450 mAh/g. Carbon capacity increased with increasing phosphoric acid concentration in the doping solution. The doped porous carbon anodes exhibited good cyclability and excellent coulombic efficiency.
Date:
November 23, 1994
Creator:
Tran, T. D.; Pekala, R. W. & Mayer, S. T.
Object Type:
Article
System:
The UNT Digital Library
Complete regional waveform modeling to estimate seismic velocity structure and source parameters for CTBT monitoring
The velocity structures and source parameters estimated by waveform modeling provide valuable information for CTBT monitoring. The inferred crustal and uppermost mantle structures advance understanding of tectonics and guides regionalization for event location and identification efforts. Estimation of source parameters such as seismic moment, depth and mechanism (whether earthquake, explosion or collapse) is crucial to event identification. In this paper we briefly outline some of the waveform modeling research for CTBT monitoring performed in the last year. In the future we will estimate structure for new regions by modeling waveforms of large well-observed events along additional paths. Of particular interest will be the estimation of velocity structure in aseismic regions such as most of Africa and the Former Soviet Union. Our previous work on aseismic regions in the Middle East, north Africa and south Asia give us confidence to proceed with our current methods. Using the inferred velocity models we plan to estimate source parameters for smaller events. It is especially important to obtain seismic moments of earthquakes for use in applying the Magnitude-Distance Amplitude Correction (MDAC; Taylor et al., 1999) to regional body-wave amplitudes for discrimination and calibrating the coda-based magnitude scales.
Date:
July 23, 1999
Creator:
Bredbeck, T.; Rodgers, A. & Walter, W.
Object Type:
Article
System:
The UNT Digital Library
Manipulating Polymer Connectivity to Control Interfacial Fracture
By studying model polymeric networks which only differ in their connectivity, the connectivity is shown to strongly control the stress-strain response and failure modes. The sequence of molecular structural deformations that lead to failure are strongly dependent upon the network connectivity. A set of ideal, ordered networks are constructed to manipulate the deformation sequence to achieve a variety of adhesive qualities. Compared to random, dynamically formed networks, these ideal networks can be made to have either much larger or smaller failure stresses and strains. Unlike the random networks, the failure stress of an ideal network can be made close to the ideal stress equal to breaking all bonds to the substrate. By varying the number of bonds to the surface, the failure mode can be controlled to be either adhesive or cohesive.
Date:
August 23, 1999
Creator:
Stevens, Mark J.
Object Type:
Article
System:
The UNT Digital Library
Shape-Selectivity with Liquid Crystal and Side-Chain Liquid Crystalline Polymer SAW Sensor Interfaces
A liquid crystal (LC) and a side-chain liquid crystalline polymer (SCLCP) were tested as surface acoustic wave (SAW) vapor sensor coatings for discriminating between pairs of isomeric organic vapors. Both exhibit room temperature smectic mesophases. Temperature, electric-field, and pretreatment with self-assembled monolayers comprising either a methyl-terminated or carboxylic acid-terminated alkane thiol anchored to a gold layer in the delay path of the sensor were explored as means of affecting the alignment and selectivity of the LC and SCLCP films. Results for the LC were mixed, while those for the SCLCP showed a consistent preference for the more rod-like isomer of each isomer pair examined.
Date:
September 23, 1999
Creator:
Zellers, Edward T.; Oborny, Michael C.; Thomas, Ross C.; Ricco, Antonio; Frye-Mason, Gregory Charles; Zhang, Guo-Zheng et al.
Object Type:
Article
System:
The UNT Digital Library
Toward crystal design in organic conductors and superconductors.
We have seen that many different types of intermolecular interactions in organic conducting cation radical salts. Hydrogen bonding between the donor molecules and the anions is weak but not negligible. The ionic Madelung energy is insufficient to completely intersperse anions and cations, thus the layers favored by the van der Waals interactions remain intact. The search for new conducting and superconducting salts has been mainly by trial-and-error methods, even though simple substitutions have been employed in order to obtain isostructural analogs of successful (e.g., superconducting) salts. However, even seemingly minor substitutions sometimes destroy the packing type, and different crystal structures result. Simulations with the aim at predicting crystal structures have not succeeded, mainly because the different interaction types are of comparable energy, and the delocalized and partial charges render the calculations of the ionic terms extremely unreliable. Clearly, the development of suitable crystal modeling techniques with predictive capabilities is one of the great needs of the field.
Date:
April 23, 1999
Creator:
Geiser, U.
Object Type:
Article
System:
The UNT Digital Library
Short range spin correlations in the CMR material La{sub 1.4}Sr{sub 1.6}Mn{sub 2}O{sub 7}.
The (La{sub 1{minus}} x Sr{sub x}){sub 3}Mn{sub 2}O{sub 7} compounds are layered materials that exhibit higher magneto-resistance than the corresponding 3D manganite perovskites. Quasi-elastic neutron scattering on a polycrystalline sample of La{sub 1.4}Sr{sub 1.6}Mn{sub 2}O{sub 7} shows that the spin fluctuation spectrum of the these layered CMR materials is qualitatively similar to those found in the perovskite manganites (La,Ca)MnO{sub 3}; their concentration, lifetime, and coherence length increase as T decreases to T{sub c}. Unlike the perovskites we find a lower spin-diffusion constant above T{sub c} of {approximately}5 meV {angstrom}{sup 2}.
Date:
March 23, 1998
Creator:
Kelley, T. M.
Object Type:
Article
System:
The UNT Digital Library
Theory of the equation of state of hot dense matter
Ab initio molecular dynamics calculations are adapted to treat dense plasmas for temperatures exceeding the electronic Fermi temperature. Extended electronic states are obtained in a plane wave basis by using pseudopotentials for the ion cores in the local density approximation to density functional theory. The method reduces to conventional first principles molecular dynamics at low temperatures with the expected high level of accuracy. The occurrence of thermally excited ion cores at high temperatures is treated by means of final state pseudopotentials. The method is applied to the shock compression Hugoniot equation of state for aluminum. Good agreement with experiment is found for temperatures ranging from zero through 105K.
Date:
July 23, 1999
Creator:
Barbee, T W; Surh, M & Yang, L H
Object Type:
Article
System:
The UNT Digital Library
Improved Efficiency of Miscible C02 Floods and Enhanced Prospects for C02 Flooding Heterogeneous Reservoirs
A grant, �Improved Efficiency of Miscible CO2 Floods and Enhanced Prospects for CO2 Flooding Heterogeneous Reservoirs,� DOE Contract No. DE-FG26-97BC15047, was awarded and started on June 1, 1997. This project examines three major areas in which CO2 flooding can be improved: fluid and matrix interactions, conformance control/sweep efficiency, and reservoir simulation for improved oil recovery. In this quarter we continued the examination of synergistic effects of mixed surfactant versus single surfactant systems to enhance the properties of foams used for improving oil recovery in CO2 floods. The purpose is to reduce the concentration of surfactants and find less expensive surfactants. Also, we are refining reservoir models to handle the complex relationships of CO2-foam and heterogeneous reservoirs. The third area of our report this quarter comprises the results from experiments on CO2-assisted gravity drainage in naturally fractured oil reservoirs. Two more CO2 core flood experiments have been conducted under reservoir conditions to investigate the effect of pressure on oil recovery efficiency during CO2-assisted gravity drainage.
Date:
January 23, 1997
Creator:
Guo, Boyun (Gordon); Schechter, David S.; Tsau, Jyun-Syung; Grigg, Reid B. & Chang, Shih-Hsien (Eric)
Object Type:
Report
System:
The UNT Digital Library
Developments in Synchrotron X-Ray Computed Microtomography at the National Synchrotron Light Source.
Last year, the X27A beamline at the National Synchrotron Light Source (NSLS) became dedicated solely to X-Ray Computed Microtomography (XCMT). This is a third-generation instrument capable of producing tomographic volumes of 1-2 micron resolution over a 2-3mm field of view. Recent enhancements will be discussed. These have focused on two issues: the desire for real-time data acquisition and processing and the need for highly monochromatic beam (.1 % energy bandpass). The latter will permit k-edge subtraction studies and will provide improved image contrast from below the Cr (6 keV) up to the Cs (36 keV) k-edge. A range of applications that benefit from these improvements will be discussed as well. These two goals are somewhat counterproductive, however; higher monochromaticity yields a lower flux forcing longer data acquisition times. To balance the two, a more efficient scintillator for X-ray conversion is being developed. Some testing of a prototype scintillator has been performed; preliminary results will be presented here. In the meantime, data reconstruction times have been reduced, and the entire tomographic acquisition, reconstruction and volume rendering process streamlined to make efficient use of synchrotron beam time. A Fast Filtered Back Transform (FFBT) reconstruction program recently developed helped to reduce the time …
Date:
July 23, 1999
Creator:
Dowd, B. A.
Object Type:
Article
System:
The UNT Digital Library
Achieving high sustained performance in an unstructured mesh CFD application.
None
Date:
August 23, 1999
Creator:
Anderson, W. K.; Gropp, W. D.; Kaushik, D. K.; Keyes, D. E. & Smith, B. F.
Object Type:
Article
System:
The UNT Digital Library
Quarterly environmental radiological survey summary - first quarter 1997 100, 200, 300, and 600 areas
This report provides a summary of the radiological surveys performed in support of near-facility environmental monitoring at the Hanford Site. The First Quarter 1997 survey results and the status of actions required are summarized below: (1) All of the routine environmental radiological surveys scheduled during January, February, and March 1997, were performed as planned. (2) One hundred four environmental radiological surveys were performed during the first quarter 1997, twenty-nine at the active waste sites and seventy-five at the inactive waste sites. Contamination above background levels was found at eight of the active waste sites and seven of the inactive waste sites. Contamination levels as high as >1,000,000 disintegrations per minute (dpm) were reported. Of these contaminated surveys twelve were in Underground Radioactive Material (URM) areas and three were in contamination areas. The contamination found within ten of the URM areas was immediately cleaned up and no further action was required. In the remaining five sites the areas were posted and will require decontamination. Radiological Problem Reports (RPR's) were issued and the sites were turned over to the landlord for further action if required. (3) During the first quarter of 1997, 5.6 hectares (13.8 acres) were stabilized and radiologically down posted …
Date:
April 23, 1997
Creator:
McKinney, S. M.
Object Type:
Report
System:
The UNT Digital Library