Research management at the interfaces (open access)

Research management at the interfaces

This contribution presents some lessons learned in the development of cooperation and knowledge transfer across the numerous interfaces involved in managing a corporate research laboratory.
Date: December 31, 1995
Creator: Westwood, A. R. C.
Object Type: Article
System: The UNT Digital Library
The effects of finite element grid density on model correlation and damage detection of a bridge (open access)

The effects of finite element grid density on model correlation and damage detection of a bridge

Variation of model size as determined by grid density is studied for both model refinement and damage detection. In model refinement 3 it is found that a large model with a fine grid is preferable in order to achieve a reasonable correlation between the experimental response and the finite element model. A smaller model falls victim to the inaccuracies of the finite element method. As the grid become increasing finer, the FE method approaches an accurate representation. In damage detection the FE method is only a starting point. The model is refined with a matrix method which doesn`t retain the FE approximation, therefore a smaller model that captures most of the dynamics of the structure can be used and is preferable.
Date: December 31, 1995
Creator: Simmermacher, T.; Mayes, R. L.; Reese, G. M.; James, G. H. & Zimmerman, D. C.
Object Type: Article
System: The UNT Digital Library
Optimal control design that accounts for model mismatch errors (open access)

Optimal control design that accounts for model mismatch errors

A new technique is presented in this paper that reduces the complexity of state differential equations while accounting for modeling assumptions. The mismatch controls are defined as the differences between the model equations and the true state equations. The performance index of the optimal control problem is formulated with a set of tuning parameters that are user-selected to tune the control solution in order to achieve the best results. Computer simulations demonstrate that the tuned control law outperforms the untuned controller and produces results that are comparable to a numerically-determined, piecewise-linear optimal controller.
Date: February 1, 1995
Creator: Kim, T. J. & Hull, D. G.
Object Type: Article
System: The UNT Digital Library
Stratigraphy of the unsaturated zone and uppermost part of the Snake River Plain aquifer at test area north, Idaho National Engineering Laboratory, Idaho (open access)

Stratigraphy of the unsaturated zone and uppermost part of the Snake River Plain aquifer at test area north, Idaho National Engineering Laboratory, Idaho

A complex sequence of basalt flows and sedimentary interbeds underlies Test Area North (TAN) at the Idaho National Engineering Laboratory in eastern Idaho. Wells drilled to depths of at least 500 feet penetrate 10 basalt-flow groups and 5 to 10 sedimentary interbeds that range in age from about 940,000 to 1.4 million years. Each basalt-flow group consists of one or more basalt flows from a brief, single or compound eruption. All basalt flows of each group erupted from the same vent, and have similar ages, paleomagnetic properties, potassium contents, and natural-gamma emissions. Sedimentary interbeds consist of fluvial, lacustrine, and eolian deposits of clay, silt, sand, and gravel that accumulated for hundreds to hundreds of thousands of years during periods of volcanic quiescence. Basalt and sediment are elevated by hundreds of feet with respect to rocks of equivalent age south and cast of the area, a relation that is attributed to past uplift at TAN. Basalt and sediment are unsaturated to a depth of about 200 feet below land surface. Rocks below this depth are saturated and make up the Snake River Plain aquifer. The effective base of the aquifer is at a depth of 885 feet below land surface. Detailed …
Date: June 1, 1995
Creator: Anderson, S. R. & Bowers, B.
Object Type: Report
System: The UNT Digital Library
Atom probe field ion microscopy of Type 308 CRE stainless steel welds (open access)

Atom probe field ion microscopy of Type 308 CRE stainless steel welds

Addition of controlled residual elements (CRE), such as 0.007 wt % B, to type 308 stainless steel welds, improved creep-rupture properties. In this paper, B distribution and microstructure development were studied. The microstructural evolution during high-temperature aging was found to similar to that of commercial SS308 welds. Atom probe analysis showed that B and C segregate to the ferrite-austenite interface. Thermodynamic calculations suggest that the segregation is due to preferential partitioning of B and C to the liquid during solidification. Further work is needed to study B redistribution in aging stages.
Date: December 31, 1995
Creator: Babu, S. S.; David, S. A.; Vitek, J. M. & Miller, M. K.
Object Type: Article
System: The UNT Digital Library
ARIES: A mobile robot inspector (open access)

ARIES: A mobile robot inspector

ARIES (Autonomous Robotic Inspection Experimental System) is a mobile robot inspection system being developed for the Department of Energy (DOE) to survey and inspect drums containing mixed and low-level radioactive waste stored in warehouses at DOE facilities. The drums are typically stacked four high and arranged in rows with three-foot aisle widths. The robot will navigate through the aisles and perform an autonomous inspection operation, typically performed by a human operator. It will make real-time decisions about the condition of the drums, maintain a database of pertinent information about each drum, and generate reports.
Date: December 31, 1995
Creator: Byrd, J. S.
Object Type: Article
System: The UNT Digital Library
Nonequilibrium multiphase mixture modeling of energetic material response (open access)

Nonequilibrium multiphase mixture modeling of energetic material response

To model the shock-induced behavior of porous or damaged energetic materials, a nonequilibrium mixture theory has been developed and incorporated into the shock physics code, CTH. Foundation for this multiphase model is based on a continuum mixture formulation given by Baer and Nunziato. In this nonequilibrium approach, multiple thermodynamic and mechanics fields are resolved including the effects of material relative motion, rate-dependent compaction, drag and heat transfer interphase effects and multiple-step combustion. Benchmark calculations are presented which simulate low-velocity piston impact on a propellant porous bed and experimentally-measured wave features are well replicated with this model. This mixture model introduces micromechanical models for the initiation and growth of reactive multicomponent flow which are key features to describe shock initiation and self-accelerated deflagration-to-detonation combustion behavior. To complement one-dimensional simulation, two dimensional numerical simulations are presented which indicate wave curvature effects due to the loss of wall confinement.
Date: December 31, 1995
Creator: Baer, M. R.; Hertel, E. & Bell, R.
Object Type: Article
System: The UNT Digital Library
Static-flow-instability in subcooled flow boiling in wide rectangular parallel channels (open access)

Static-flow-instability in subcooled flow boiling in wide rectangular parallel channels

The Advanced Neutron Source (ANS) is a state-of-the-art research reactor facility that will be built at the Oak Ridge National Laboratory (ORNL) and is designed to become the world`s most advanced thermal neutron flux source for scientific experiments. Therefore, the core of the ANS reactor (ANSR) must be designed to accommodate very high power densities using very high coolant mass fluxes and subcooling levels, The nominal average and peak heat fluxes in the ANSR are approximately 6 and 12 MW/M{sup 2}, respectively, with a nominal total thermal power of 303 MW. Highly subcooled heavy-water coolant (1.7 MPa and 85{degrees}C at the core exit) flows vertically upward at a very high mass flux of almost 27 Mg/M{sup 2}-s. The cooling channels in each fuel assembly are all parallel and share common inlet and outlet plenums, effectively imposing a common pressure drop across all the channels. This core configuration is subject to flow excursion (FE) and/or flow instability that may occur once boiling is initiated in any one of the channels. The FE phenomenon constitutes a different thermal limit than a true critical heat flux (CHF) or departure from nucleate boiling (DNB). In such a system, initiation of boiling in one of …
Date: December 31, 1995
Creator: Siman-Tov, M.; Felde, D. K.; McDuffee, J. L. & Yoder, G. L. Jr.
Object Type: Article
System: The UNT Digital Library
The accident site portable integrated video system (open access)

The accident site portable integrated video system

This paper presents a high bandwidth fiber-optic communication system intended for post accident recovery of weapons. The system provides bi-directional multichannel, and multi-media communications. Two smaller systems that were developed as direct spin-offs of the larger system are also briefly discussed.
Date: December 31, 1995
Creator: Jones, D. P.; Shirey, D. L. & Amai, W. A.
Object Type: Article
System: The UNT Digital Library
Coplanar multiple-ring electrostatic particle-beam lenses (open access)

Coplanar multiple-ring electrostatic particle-beam lenses

Electrostatic particle-beam lenses using a concentric co-planar array of independently biased rings can be advantageous for some applications. Traditional electrostatic lenses often consist of axial series of biased rings, apertures, or tubes. The science of lens design has devoted much attention to finding axial arrangements that compensate for the substantial optical aberrations of the individual elements. Thus, as with multi-element lenses for light, a multi-element charged-particle lens can have optical behavior that is far superior to that of the individual elements. This paper discusses the possibility that transverse multiple-concentric-ring lenses can achieve high performance, while also having advantages in terms of compactness and optical versatility.
Date: December 31, 1995
Creator: Moran, M. J.
Object Type: Article
System: The UNT Digital Library
Pulsed power drivers for ICF and high energy density physics (open access)

Pulsed power drivers for ICF and high energy density physics

Nanosecond Pulsed Power Science and Technology has its origins in the 1960s and over the past decade has matured into a flexible and robust discipline capable of addressing key physics issues of importance to ICF and high Energy Density Physics. The major leverage provided by pulsed power is its ability to generate and deliver high energy and high power at low cost and high efficiency. A low-cost, high-efficiency driver is important because of the very large capital investment required for multi-megajoule ignition-class systems. High efficiency is of additional importance for a commercially viable inertial fusion energy option. Nanosecond pulsed power has been aggressively and successfully developed at Sandia over the past twenty years. This effort has led to the development of unique multi-purpose facilities supported by highly capable diagnostic, calculational and analytic capabilities. The Sandia Particle-beam Fusion Program has evolved as part of an integrated national ICF Program. It applies the low-cost, high-efficiency leverage provided by nanosecond pulsed power systems to the longer-term goals of the national program, i.e., the Laboratory Microfusion Facility and Inertial Fusion Energy. A separate effort has led to the application of nanosecond pulsed power to the generation of intense, high-energy laboratory x-ray sources for application …
Date: December 31, 1995
Creator: Ramirez, J. J.; Matzen, M. K. & McDaniel, D. H.
Object Type: Article
System: The UNT Digital Library
High gain GaAs Photoconductive Semiconductor Switches (PCSS): Device lifetime, high current testing, optical pulse generators (open access)

High gain GaAs Photoconductive Semiconductor Switches (PCSS): Device lifetime, high current testing, optical pulse generators

This paper presents results from three areas of GaAs PCSS research and development: device lifetime, high current switching, and PCSS-driven laser diode arrays (LDA). The authors have performed device lifetime tests on both lateral and vertical switches as a function of current amplitude, pulse width, and charging time. At present, their longest-lived switch reached 4 {times} 10{sup 6} pulses. Scanning electron microscope (SEM) images show damage near the contacts even after only 5 pulses. They are presently searching for the threshold at which no damage is evident after a single shot. In high current tests, they have reached 5.2 kA at 4.2 kV. This was achieved using twenty fiber-optic coupled lasers to distribute current filaments over a 5 mm wide PCSS. Current waveforms and images of the current filaments as a function of current amplitude will be presented. The lasers used to trigger the high current PCSS were driven with a miniature PCSS. Low inductance, high speed GaAs PCSS are very effective as short pulse laser diode array drivers. Some types of arrays gain switch, producing a compressed optical pulse which is only 75 ps wide. Results from tests with a variety of laser diode arrays will be presented.
Date: December 31, 1995
Creator: Zutavern, F. J.; Loubriel, G. M.; Helgeson, W. D.; O`Malley, M. W.; Gallegos, R. R.; Hjalmarson, H. P. et al.
Object Type: Article
System: The UNT Digital Library
Capillary flow on narrow strips and in V-shaped grooves (open access)

Capillary flow on narrow strips and in V-shaped grooves

Simple models for the flow of solder onto a copper metallized strip and into V-shaped groves in copper were derived and compared to experimental results. The conditions for initiation of flow are established and followed by the determination of flow rates for the two geometrical configurations. The analysis leads to the conclusion that the standard approach to capillary flow is adequate for describing these kinetics. A computer simulation using the interfacial energy minimization code Surface Evolver, is also used to examine these systems and it is shown that it does predict the experimentally observed morphologies. The two approaches are compared and similarities are discussed.
Date: December 31, 1995
Creator: Yost, F. G. & Holm, E. A.
Object Type: Article
System: The UNT Digital Library
Proceedings: pellet fuels conference (open access)

Proceedings: pellet fuels conference

The conference brought together professionals from the process- engineered-fuels (PEF), utility, paper, plastics, and boiler industries. Although the last two decades have produced technical breakthroughs, efforts to advance PEF must now focus on increasing commercial breakthroughs. Successful commercialization will depend on increasing supplier, consumer, and regulator confidence and support by demonstrating the performance and value of PEF products. Speakers provided updates on how PEF technology is evolving with respect to technical, economic, and regulatory challenges. Actions critical toward full commercialization of PEF were then considered. Discussion groups addressed materials sourcing, fuel processing and transportation, combustion, and ash handling.
Date: December 1995
Creator: unknown
Object Type: Article
System: The UNT Digital Library
Radionuclide air emissions annual report for calendar year 1994 (open access)

Radionuclide air emissions annual report for calendar year 1994

This report presents the results of the Pinellas Plant air sampling program for the year of 1994. Topics discussed include: site description; source description; air emissions data; dose assessments; description of dose model; summary of input parameters of dose model; unplanned releases; and diffuse emissions. Included in the attachments of this document are: non-radon individual dose assessment; non-radon population dose assessment; summary of stack flow rate measurements; HOTSPOT computer model run; and meteorological data for the Pinellas Plant for 1994.
Date: April 4, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Hot Dry Rock Geothermal Energy in the Usa: Moving Toward Practical Use (open access)

Hot Dry Rock Geothermal Energy in the Usa: Moving Toward Practical Use

The technology for extracting geothermal energy from the vast hot dry rock (HDR) geothermal resource has been under development by the Los Alamos National Laboratory for about 25 years. In 1992--1993, an extensive flow-testing program was conducted at the Fenton Hill, New Mexico HDR Test Facility. During two segments of this test energy was produced at a rate of 4 thermal megawatts on a continuous basis for periods of 112 and 65 days, respectively. Surface and logging measurements showed no decline in the temperature of the water produced from the HDR reservoir during the flow testing. In fact, tracer evidence indicated that the circulating water was continually gaining access to additional hot rock as the testing proceeded. Water consumption was low and all other test data were positive. The encouraging results of the flow testing at Fenton Hill provided the incentive for the United States Department of Energy (USDOE) to solicit the interest of private industry in a jointly funded program to construct and operate a facility that would produce and sell energy derived from HDR resources. A number of organizations responded positively. On the basis of the interest expressed in these responses, the USDOE subsequently authorized the issuance of …
Date: December 31, 1995
Creator: Duchane, David V.
Object Type: Article
System: The UNT Digital Library
Experimental studies of longitudinal dynamics of space-charge dominated electron beams (open access)

Experimental studies of longitudinal dynamics of space-charge dominated electron beams

A comprehensive experimental program was carried out at Univ. of Maryland Beam Transport facility to study the longitudinal beam physics of space-charge dominated bunches. This investigation included the behavior of (a) bunches with parabolic line charge profile, (b) bunches with rectangular line charge profile, and (c) local perturbations (slow and fast waves) in rectangular bunches. The major experimental results are presented in this paper.
Date: December 31, 1995
Creator: Wang, D. X.
Object Type: Article
System: The UNT Digital Library
Theoretical and experimental study of mixed solvent electrolytes. Final report, February 1, 1994--January 31, 1995 (open access)

Theoretical and experimental study of mixed solvent electrolytes. Final report, February 1, 1994--January 31, 1995

The research objectives were: perform Gibbs ensemble Monte Carlo simulation of mixed solvent electrolytes (ethanol/water/NaCl); perform molecular dynamics simulation of supercritical aqueous (electrolyte) solutions; measure experimentally phase equilibria in water/alcohol/organic salt mixtures; and conduct integral equation studies of mixed solvent electrolytes. Progress on all objectives is reported (the most progress was on the molecular dynamics simulation).
Date: December 31, 1995
Creator: Cummings, P. T.
Object Type: Report
System: The UNT Digital Library
A drillable straddle packer for lost circulation control in geothermal drilling (open access)

A drillable straddle packer for lost circulation control in geothermal drilling

Lost circulation is a persistent problem in geothermal drilling and often accounts for a significant fraction of the cost of drilling a typical geothermal well. The US Department of Energy sponsors work at Sandia National Laboratories to develop technology for reducing lost circulation costs. This paper describes a downhole tool that has been developed at Sandia for improving the effectiveness and reducing the cost of cementing operations used to treat lost circulation zones. This tool, known as the drillable straddle packer, is a low-cost, disposable assembly used for isolating a loss zone and directing the flow of cement into the zone. This paper describes the tool concept, hardware design, deployment procedure, laboratory testing, and technical issues addressed during the development process.
Date: December 31, 1995
Creator: Glowka, D. A.
Object Type: Article
System: The UNT Digital Library
Resolve at CEBAF (open access)

Resolve at CEBAF

M. Lee`s program RESOLVE has recently been in extensive use at CEBAF to help identify and correct optics problems in recirculation arcs and in linac beamlines encountered during the commissioning of the 4- GeV accelerator. We describe the integration of the program with our machine applications software package. A significant vertical focusing error in one of the recirculation arcs, which is attributed to edge focusing of dipole magnets, was found from the analysis of difference orbit measurement data. A corrective measure has been successfully implemented. Optics checks in the spreader and recombiner regions are discussed along with linac optics and 60Hz jitter. 7 refs., 4 figs.
Date: December 31, 1995
Creator: Yunn, B. C.; Li, R. & Simrock, S.
Object Type: Article
System: The UNT Digital Library
Environmental management technology demonstration and commercialization (open access)

Environmental management technology demonstration and commercialization

This document contains several abstracts of talks given to `Opportunity `95 - Environmental Technology Through Small Business.` Titles include the following: Pyrolysis of Plastic Waste; Subcritical water extraction of organic pollutants and extraction of hazardous metals from mixed solid wastes by chelation and supercritical fluid extraction; extraction and analysis of pollutant organics from contaminated solids using off-line supercritical fluid extraction and on-line SFE/IR; Stabilization of vitrified waste by enhanced crystallization and development of a protocol to predict long-term stability.
Date: February 1, 1995
Creator: Jones, M. L.; Beaver, F. W.; Benson, S. A.; Steadman, E. N.; Hawthorne, S. B.; Hurley, J. P. et al.
Object Type: Article
System: The UNT Digital Library
Tritium Processing and Containment Practices at the Savannah River Site (open access)

Tritium Processing and Containment Practices at the Savannah River Site

This report emphasizes the features of the United States Tritium Facility operation at the Savannah River Site. It outlines the buildings that represent the facility operating basis. It explores areas where new technology and proven methods of operation developed at the Site have made dramatic environmental and facility work enhancements over the last several years. These enhancements should be consideration for future facility designs and for any current tritium missions.
Date: March 1, 1995
Creator: Buley, R. D.; Green, D. J. & Metzler, J.
Object Type: Article
System: The UNT Digital Library
Development of density and temperature profile diagnostics for ICF targets. Final report, September 30, 1993--December 31, 1994 (open access)

Development of density and temperature profile diagnostics for ICF targets. Final report, September 30, 1993--December 31, 1994

In the authors` research for the period of September 30, 1993 through December 31, 1994, they have upgraded their equipment in anticipation of the restart of the upgraded lasers at the University of Rochester Laboratory for Laser Energetics/National Laser User Facility (LLE/NLUF) and elsewhere. As a direct result of cooperation with Dr. Paul Jaanimagi of LLE, they have modified the cathode on a LLE-designed front-illuminated streak camera so as to operate over a wavelength range extending from the x-ray ({ge} 0.3 nm) into the vacuum ultraviolet (> 100 nm) spectral regions. They have accomplished this with (coated) screen cathodes which permit the photoelectrons to freely penetrate through the openings after emission from the mesh surfaces. Such cathodes were studied, compared and optimized. In anticipation of the development of these long-wavelength photocathodes, they assembled and tested a xuv flat-field streak spectrograph using a varied-spacing grating and covering the 4--30 nm wavelength region. They successfully obtained spectra of highly-ionized boron and carbon. They have also installed a new 300 grooves/mm, 4.2{degree} blazed grating in their ``McPig`` microchannel plate equipped grazing incidence spectrograph, and obtained test spectra extending from 3 to 140 nm wavelength.
Date: March 1, 1995
Creator: Griem, Hans R. & Elton, Raymond C.
Object Type: Report
System: The UNT Digital Library
Report on the study of radiation damage in CaF{sub 2} and MgF{sub 2} windows for excimer laser applications (open access)

Report on the study of radiation damage in CaF{sub 2} and MgF{sub 2} windows for excimer laser applications

None
Date: September 20, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library