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Polk County Enterprise (Livingston, Tex.), Vol. 117, No. 40, Ed. 1 Thursday, May 20, 1999
Semi-weekly newspaper from Livingston, Texas that includes local, state and national news along with advertising.
Date:
May 20, 1999
Creator:
White, Barbara
Object Type:
Newspaper
System:
The Portal to Texas History
Polk County Enterprise (Livingston, Tex.), Vol. 117, No. 49, Ed. 1 Sunday, June 20, 1999
Semi-weekly newspaper from Livingston, Texas that includes local, state and national news along with advertising.
Date:
June 20, 1999
Creator:
White, Barbara
Object Type:
Newspaper
System:
The Portal to Texas History
Hondo Anvil Herald (Hondo, Tex.), Vol. 113, No. 20, Ed. 1 Thursday, May 20, 1999
Weekly newspaper from Hondo, Texas that includes local, state, and national news along with extensive advertising.
Date:
May 20, 1999
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History
U.S./Russian cooperative efforts to enhance nuclear MPC&A at VNIITF, (Chelyabinsk-70)
The work described here is part of an effort called the Nuclear Materials Protection, Control, and Accounting (MPC&A) Program, a cooperative program between the US Department of Eenrgy (DOE) and Russia's Ministry of Atomic Energy (MinAtom). The objective of the program is to reduce the risk of nuclear proliferation by strengthening MPC&A systems at Russian nuclear Facilities. This paper describes that portion of the MPC&A program that is directed specifically to the needs of the All Russian Scientific Research Institute of Technical Physics (VNIITF), also called Chelyabinsk-70. A major MPC&A milestone was met at VNIITF when the MPC&A improvements were commissioned at the Pulse Research Reactor Facility in May of this year.
Date:
April 20, 1999
Creator:
Abramson, B.; Apt, K.; Blasy, J.; Bukin, D.; Churikov, Y.; Curtis, D. et al.
Object Type:
Article
System:
The UNT Digital Library
Human Impacts and Management of Carbon Sources
The energy system dominates human-induced carbon flows on our planet. Globally, six billion tons of carbon are contained in the fossil fuels removed from below the ground every year. More than 90% of the carbon in fossil fuels is used for energy purposes, with carbon dioxide as the carbon product and the atmosphere as the initial destination for the carbon dioxide. Significantly affecting the carbon flows associated with fossil fuels is an immense undertaking. Four principal technological approaches are available to affect these carbon flows: (1) Fossil fuels and other energy resources can be utilized more efficiently; (2) Energy sources other than fossil fuels can be used; (3) Carbon dioxide from the combustion of fossil fuels can be trapped and redirected, preventing it from reaching the atmosphere (fossil carbon sequestration); and (4) One can work outside the energy system to remove carbon dioxide biologically from the atmosphere (biological carbon sequestration). An optimum carbon management strategy will surely implement all four approaches and a wise R&D program will have vigorous sub-programs in all four areas. These programs can be effective by integrating scenario analyses into the planning process. A number of future scenarios must be evaluated to determine the need for …
Date:
August 20, 1999
Creator:
Benson, S.; Edmonds, J.; Socolow, R. & Surles, T.
Object Type:
Report
System:
The UNT Digital Library
Novel interferometer spectrometer for sensitive stellar radial velocimetry
We describe a new kind of stellar radial velocimeter based on the series combination of a wide angle Michelson interferometer and a disperser, and which we call a fringing spectrometer. The simplest instrument response of the interferometer produces smaller instrumental noise, and the low resolution requirements of the disperser allows high efficiency and creates an etendue capability which is two orders of magnitude larger than current radial velocimeters. The instrument is compact, inexpensive and portable. Benchtop tests of an open-air prototype shows the short term instrumental noise to be less than 0.76 m/s. A preliminary zero point drift of 4 m/s is already competitive with traditional instruments, in spite of the lack of obvious environmental controls and a known interferometer cavity length drift. We are currently installing cavity stabilization and other improvements that will lead to testing on starlight.
Date:
May 20, 1999
Creator:
Erskine, D & Ge, J
Object Type:
Article
System:
The UNT Digital Library
An Evaluation of Power Law Breakdown in Metals, Alloys, Dispersion Hardened Materials and Compounds
Creep at high stresses often produces strain rates that exceed those that would be predicted by a power law relationship. In this paper, we examine available high stress creep data for pure metals, solid solution alloys, dispersion strengthened powder metallurgy materials and compounds for power law breakdown (PLB). The results show that, if PLB is observed, then the onset of PLB is generally observed at about {epsilon}/D{sub eff} = 10{sup 13} m{sup -2}, where D{sub eff} is the effective diffusion coefficient incorporating lattice and dislocation pipe diffusion. The common origins of PLB for the various systems studied can be found in the production of excess vacancies by plastic deformation. Anomalous behavior in two pure metals (nickel and tungsten) and a solid solution alloy (Fe-25Cr and Fe-26Cr-1Mo) has been analyzed and provides insight into this excess vacancy mechanism. In metal systems, the onset of PLB is related to a change in the nature of the subgrain structure developed. In the PLB region, subgrains become imperfect containing dislocation tangles adjacent to the sub-boundary, and dislocation cells are evident. The dislocation tangles and cells are the source of excess vacancies and increase the creep rate above that predicted from power law creep. If …
Date:
October 20, 1999
Creator:
Lesuer, D. R.; Syn, C. K. & Sherby, O. D.
Object Type:
Article
System:
The UNT Digital Library
Hydrogen Peroxide Storage in Small Sealed Tanks
Unstabilized hydrogen peroxide of 85% concentration has been prepared in laboratory quantities for testing material compatibility and long term storage on a small scale. Vessels made of candidate tank and liner materials ranged in volume from 1 cc to 2540 cc. Numerous metals and plastics were tried at the smallest scales, while promising ones were used to fabricate larger vessels and liners. An aluminum alloy (6061-T6) performed poorly, including increasing homogeneous decay due to alloying elements entering solution. The decay rate in this high strength aluminum was greatly reduced by anodizing. Better results were obtained with polymers, particularly polyvinylidene fluoride. Data reported herein include ullage pressures as a function of time with changing decay rates, and contamination analysis results.
Date:
October 20, 1999
Creator:
Whitehead, J.
Object Type:
Article
System:
The UNT Digital Library
Material Failure and the Growth of Instabilities in Hollow Cylindrical Samples of Aluminum Shocked to 14Gpa and 50Gpa (U)
Understanding the surface stability of metals undergoing dynamic fracture at shock breakout is important to several applications in metals processing. The advantages of using the Pegasus II facility to investigate the phenomena occurring at shock break out are described. As an example of the data collected, we concentrate on brief descriptions of two experiments that compared the tensile failure, i.e. ''spall'', patterns in the presence of sinusoidal perturbations seeded on the free inner surface of cylindrical samples made of structural grade Al 6061.T6. These samples were subjected to ramped waves with shock pressures of 14 GPa and 50 GPa to observe the effect of pressure on the production of a type of volumetric failure that is mentioned here ''microspall.'' This failed region behind the exiting surface of the shock wave is comprised of a significant volume of low-density, probably granular, material. The failure mechanism, combined with the forces that cause inertial instability, leads to rapid pattern growth in the failed material, observable as density variations, as well as to pattern growth on the surface. Pattern growth was observed to vary with perturbation amplitude, wavelength, and shock pressure. Both increased pressure and increased amplitude were shown to destabilize a stable perturbation. …
Date:
November 20, 1999
Creator:
Stokes, J.; Fulton, R. D.; Morgan, D. V.; Obst, A. W.; Oro, D. M.; Oona, H. et al.
Object Type:
Article
System:
The UNT Digital Library
Total Measurement Uncertainty (TMU) for Nondestructive Assay of Transuranic (TRU) Waste at the WRAP Facility
This report examines the contributing factors to NDA measurement uncertainty at WRAP. The significance of each factor on the TMU is analyzed, and a final method is given for determining the TMU for NDA measurements at WRAP. As more data becomes available, and WRAP gains in operational experience, this report will be reviewed semi-annually and updated as necessary.
Date:
September 20, 1999
Creator:
WILLS, C.E.
Object Type:
Report
System:
The UNT Digital Library
Dual-Side Wafer Processing and Resonant Tunneling Transistor Applications
We describe dual-side wafer processing and its application to resonant tunneling transistors in a planar configuration. The fabrication technique utilizes a novel flip-chip, wafer thinning process called epoxy-bond and stop-etch (EBASE) process, where the substrate material is removed by selective wet etching and stopped at an etch-stop layer. This EBASE method results in a semiconductor epitaxial layer that is typically less than a micron thick and has a mirror-finish, allowing backside gates to be placed in close proximity to frontside gates. Utilizing this technique, a resonant tunneling transistor--the double electron layer tunneling transistor (DELTT)--can be fabricated in a fully planar configuration, where the tunneling between two selectively-contacted 2DEGs in GaAs or InGaAs quantum wells is modulated by surface Schottky gate. Low temperature electrical characterization yields source-drain I-V curves with a gate-tunable negative differential resistance.
Date:
July 20, 1999
Creator:
Moon, J. S.; Simmons, J. A.; Wendt, J. R.; Hietala, V. M.; Reno, J. L.; Baca, W. E. et al.
Object Type:
Article
System:
The UNT Digital Library
A Practical Approach for Integrating Automatically Designed Fixtures with Automated Assembly Planning
This paper presents a practical approach for integrating automatically designed fixtures with automated assembly planning. Product assembly problems vary widely; here the focus is on assemblies that are characterized by a single base part to which a number of smaller parts and subassemblies are attached. This method starts with three-dimension at CAD descriptions of an assembly whose assembly tasks require a fixture to hold the base part. It then combines algorithms that automatically design assembly pallets to hold the base part with algorithms that automatically generate assembly sequences. The designed fixtures rigidly constrain and locate the part, obey task constraints, are robust to part shape variations, are easy to load, and are economical to produce. The algorithm is guaranteed to find the global optimum solution that satisfies these and other pragmatic conditions. The assembly planner consists of four main elements: a user interface, a constraint system, a search engine, and an animation module. The planner expresses all constraints at a sequencing level, specifying orders and conditions on part mating operations in a number of ways. Fast replanning enables an interactive plan-view-constrain-replan cycle that aids in constrain discovery and documentation. The combined algorithms guarantee that the fixture will hold the base …
Date:
July 20, 1999
Creator:
Calton, Terri L. & Peters, Ralph R.
Object Type:
Article
System:
The UNT Digital Library
A Modular Telerobot Control System for Accident Response
The Accident Response Mobile Manipulator System (ARMMS) is a teleoperated emergency response vehicle that deploys two hydraulic manipulators, five cameras, and an array of sensors to the scene of an incident. It is operated from a remote base station that can be situated up to four kilometers away from the site. Recently, a modular telerobot control architecture called SMART (Sandia's Modular Architecture for Robotic and Teleoperation) was applied to ARMMS to improve the precision, safety, and operability of the manipulators on board. Using SMART, a prototype manipulator control system was developed in a couple of days, and an integrated working system was demonstrated within a couple of months. New capabilities such as camera teleoperation, autonomous tool changeout and dual manipulator control have been incorporated. The final system incorporates twenty-two separate modules and implements eight different behavior modes. This paper describes the integration of SMART into the ARMMS system.
Date:
July 20, 1999
Creator:
Anderson, Robert J. & Shirey, David L.
Object Type:
Article
System:
The UNT Digital Library
Molecular Dynamics Simulation of the Structure and Properties of Lithium Phosphate Glasses
A new forcefield model was developed for modeling phosphate materials that have many important applications in the electronics and biomedical industries. Molecular dynamics simulations of a series of lithium phosphate glass compositions were performed using the new forcefield model. A high concentration of three member rings (P{sub 3}O{sub 3}) was found in the glass of intermediate composition (0.2 Li{sub 2}O {center_dot} 0.8 P{sub 2}O{sub 5}) that corresponds to the minimum in the glass transition temperature curve for the compositional series.
Date:
July 20, 1999
Creator:
Liang, Jian-jie; Cygan, Randall T. & Alam, Todd M.
Object Type:
Article
System:
The UNT Digital Library
An Integrated Surface Acoustic Wave-Based Chemical Microsensor Array for Gas-Phase Chemical Analysis Microsystems
This paper describes preliminary results in the development of an acoustic wave (SAW) microsensor array. The array is based on a novel configuration that allows for three sensors and a phase reference. Two configurations of the integrated array are discussed: a hybrid multichip-module based on a quartz SAW sensor with GaAs microelectronics and a fully monolithic GaAs-based SAW. Preliminary data are also presented for the use of the integrated SAW array in a gas-phase chemical micro system that incorporates microfabricated sample collectors and concentrators along with gas chromatography (GC) columns.
Date:
July 20, 1999
Creator:
Casalnuovo, stephen A.; Frye-Mason, Gregory C.; Heller, Edwin J.; Hietala, Vincent M.; Kottenstette, Richard J.; Lewis, Patrick R. et al.
Object Type:
Article
System:
The UNT Digital Library
Nucleation and Growth During Faceting of the Platinum Covered W(111) Surface
Low energy electron microscopy (LEEM) and scanning tunneling microscopy (STM) have been used to investigate the faceting of W(111) as induced by Pt. The atomically rough W(111) surface, when fully covered with a monolayer film of Pt and annealed to temperatures higher than {approximately}750 K, experiences a significant morphological restructuring: the initially planar surface undergoes a faceting transition and forms three-sided pyramids with {l_brace}211{r_brace} faces. When Pt is dosed onto the heated surface, the transition from planar to faceted structure proceeds through the nucleation and growth of spatially separated faceted regions, as shown by LEEM. STM reveals the atomic structure of the partially faceted surface, with large planar regions, dotted by clusters of pyramids of various sizes.
Date:
July 20, 1999
Creator:
Hannon, J. B.; Kellogg, G. L.; Madey, T. E. & Pelhos, K.
Object Type:
Article
System:
The UNT Digital Library
CDF Run II Discovery reach for neutral MSSM higgs bosons via p pbar {right arrow}b b-bar {phi}{right arrow}b b-bar b b-bar
In this paper we examine the CDF Run II discovery reach for neutral Higgs bosons via the process p{anti p} {yields} b {anti b} {phi} {yields} b {anti b}b {anti b}. The signature is a four jet final state with at least three b-tagged jets. Signal and background acceptances are estimated using the CDF Run I detector performance. b tagging efficiencies and fake tag rates are evaluated with new Run II increased detector geometrical acceptances. Total rates are estimated from present Run I data and from Monte Carlo. The results are interpreted within the framework of the minimal supersymmetric extension of the standard model (MSSM) and generalized in terms of a model independent enhancement factor.
Date:
July 20, 1999
Creator:
Valls, J.A.
Object Type:
Article
System:
The UNT Digital Library
Clean Cities Award Winning Coalition: Salt Lake City
Since its designation as a national Clean City in 1994, Salt Lake Clean Cities has put more than 2,600 alternative fuel vehicles (AFVs) on community streets. The 82 business, nonprofit, and government agencies that comprise the coalition are all dedicated to cleaning the air by reducing vehicle exhaust. Salt Lake Clean Cities has the third largest compressed natural gas and propane-refueling infrastructure in the country, with 98 locations available. They sponsor an annual ''Spring Soiree'' to increase public awareness about the program and educate the public about the benefits of alternative fuel and AFVs.
Date:
May 20, 1999
Creator:
Kaiser, ICF
Object Type:
Book
System:
The UNT Digital Library
Clean Cities Award Winning Coalition: Greater Long Island
This coalition was the culmination a two-year joint effort by Long Island Lighting Company and the Long Island Regional Planning Board. The group's first alternative fuel project was a single fill compressed natural gas station and a converted Chevrolet Caprice. Since then, the coalition has made steady progress in the alternative fuel and alternative fuel vehicle (AFV) market. They have over 400 AFVs and 21 fueling stations in their operating area. Thanks to strong partnerships with local public and private organizations, they've also passed some of the most progressive state tax incentive legislation for AFVs in the country.
Date:
May 20, 1999
Creator:
Kaiser, ICF
Object Type:
Book
System:
The UNT Digital Library
HIGH TEMPERATURE HIGH PRESSURE THERMODYNAMIC MEASUREMENTS FOR COAL MODEL COMPOUNDS
It is well known that the fluid phase equilibria can be represented by a number of {gamma}-models , but unfortunately most of them do not function well under high temperature. In this calculation, we mainly investigate the performance of UNIQUAC and NRTL models under high temperature, using temperature dependent parameters rather than using the original formulas. the other feature of this calculation is that we try to relate the excess Gibbs energy G{sup E}and enthalpy of mixing H{sup E}simultaneously. In other words, we will use the high temperature and pressure G{sup E} and H{sup E}data to regress the temperature dependant parameters to find out which model and what kind of temperature dependant parameters should be used.
Date:
February 20, 1999
Creator:
Kabadi, Vinayak N.
Object Type:
Report
System:
The UNT Digital Library
Pulse width dispersion at 351nm in single fibers with diameters of 100 and 435 microns, and in a bundle of 19 fibers
Pulse width broadening at 351-nm was measured in two single fibers (core sizes 100 and 435 µm), and in a 32-m bundle of 19 each 50-µm-core fibers.
Date:
January 20, 1999
Creator:
Thompson, C. E.; Sell, W.; Milam, D.; Griffith, R. & Hollis, J.
Object Type:
Report
System:
The UNT Digital Library
Atmospheric Test Models and Numerical Experiments for the Simulation of the Global Distributions of Weather Data Transponders III. Horizontal Distributions
A network of small balloon-borne transponders which gather very high resolution wind and temperature data for use by modern numerical weather predication models has been proposed to improve the reliability of long-range weather forecasts. The global distribution of an array of such transponders is simulated using LLNL's atmospheric parcel transport model (GRANTOUR) with winds supplied by two different general circulation models. An initial study used winds from CCM3 with a horizontal resolution of about 3 degrees in latitude and longitude, and a second study used winds from NOGAPS with a 0.75 degree horizontal resolution. Results from both simulations show that reasonable global coverage can be attained by releasing balloons from an appropriate set of launch sites.
Date:
December 20, 1999
Creator:
Molenkamp, C.R. & Grossman, A.
Object Type:
Report
System:
The UNT Digital Library
Cold Vacuum Drying (CVD) Facility Design Basis Accident Analysis Documentation
This document provides the detailed accident analysis to support HNF-3553, Annex B, Spent Nuclear Fuel Project Final Safety Analysis Report, ''Cold Vacuum Drying Facility Final Safety Analysis Report (FSAR).'' All assumptions, parameters and models used to provide the analysis of the design basis accidents are documented to support the conclusions in the FSAR.
Date:
October 20, 1999
Creator:
Piepho, M .G.
Object Type:
Report
System:
The UNT Digital Library
B-cell waste classification sampling plan
This report documents the methods used to collect samples and analyze data necessary to verify and/or determine the radionuclide content of the 324 Facility B-Cell decontamination and decommissioning waste stream.
Date:
November 20, 1999
Creator:
Hobart, R. L.
Object Type:
Report
System:
The UNT Digital Library