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Using spallation neutron sources for defense research
Advanced characterization techniques and accelerated simulation are the cornerstones of the Energy Department`s science-based program to maintain confidence in the safety, reliability, and performance of the US nuclear deterrent in an era of no nuclear testing. Neutrons and protons provided by an accelerator-based facility have an important role to play in this program, impacting several of the key stockpile stewardship and management issues identified by the Department of Defense. Many of the techniques used for defense research at a spallation source have been used for many years for the basic research community, and to a lesser extent by industrial scientists. By providing access to a broad spectrum of researchers with different backgrounds, a spallation source such as the Los Alamos Neutron Science Center is able to promote synergistic interaction between defense, basic and industrial researchers. This broadens the scientific basis of the stockpile stewardship program in the short term and will provide spin-off to industrial and basic research in the longer term.
Date:
December 31, 1996
Creator:
Pynn, R.; Sterbenz, S. M. & Weinacht, D. J.
Object Type:
Article
System:
The UNT Digital Library
Using the Remote Access Protocol for usability evaluation in X Windows
The automatic evaluation of graphical user interfaces can help reduce development costs in the creation of new designs or modification of existing designs. Several standards for the X Window System have been proposed or implemented that could greatly reduce the time spent evaluating GUIs. We implemented a User Interface Testbed (UseIT) based on the proposed Remote Access Protocol (RAP) standard. UseIT was created to automatically record an end user`s interaction with a Motif GUI application without modification or re-linking of existing code. The recorded interaction could then be replayed or displayed visually for interpretation by a human factors specialist. The end goal was to recreate the GUI and automatically recommend design changes based upon the interactions.
Date:
December 31, 1996
Creator:
Edwards, T.; Bauer, K. & Allen, H.
Object Type:
Article
System:
The UNT Digital Library
Utility Advanced Turbine System (ATS) technology readiness testing and pre-commercial demonstration -- Phase 3. Quarterly report, April 1--June 30, 1996
The overall objective of the Advanced Turbine System (ATS) Phase 3 Cooperative Agreement between GE and the US Department of Energy (DOE) is the development of the GE 7H and 9H combined cycle power systems. The major effort will be expended on detailed design. Validation of critical components and technologies will be performed including: hot gas path component testing, sub-scale compressor testing, steam purity test trials, and rotational heat transfer confirmation testing. Processes will be developed to support the manufacture of the first system, which will be sited and operated in Phase 4. Technology enhancements that are not required for the first machine design but will be critical for future ATS advances in performance, reliability, and costs will be initiated. Long-term tests of materials to confirm design life predictions will continue. This report summarizes work accomplished during the period 2Q96.
Date:
December 31, 1996
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Utility Advanced Turbine System (ATS) technology readiness testing and pre-commercialization demonstration. Quarterly report, January 1--March 31, 1996
Objective of ATS Phase 3 is development of GE 7H and 9H combined cycle power systems. This report summarizes work accomplished during the period 1Q96, including NEPA environmental information.
Date:
December 31, 1996
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Utilization of Lightweight Materials Made from Coal Gasificaiton Slags
The integrated gasification combined-cycle (IGCC) coal conversion process has been demonstrated to be a clean, efficient, and environmentally acceptable method of generating power; however, it generates solid waste materials in relatively large quantities. For example, a 400-MW power plant using 4000 tons of 10% ash coal per day may generate over 440 tons/day of solid waste of slag, consisting of vitrified mineral matter and unburned carbon. The disposal of the wastes represents significant costs. Regulatory trends with respect to solid wastes disposal, landfill development costs and public concern make utilization of solid wastes a high-priority issue. As coal gasification technologies find increasing commercial applications for power generation or production of chemical feed stocks, it becomes imperative that slag utilization methods be developed, tested and commercialized in order to offset disposal costs. Praxis is working on a DOE/METC funded project to demonstrate the technical and economic feasibility of making lightweight and ultra-lightweight aggregates from slags left as solid by-products from the coal gasification process. The project objectives are to develop and demonstrate the technology for producing slag-based lightweight aggregates (SLA), to produce 10 tons of SLA products with different unit weights from two slags, to collect operational and emissions data from …
Date:
December 31, 1996
Creator:
Choudhry, V. & Hadley, S.
Object Type:
Report
System:
The UNT Digital Library
Utilization of lightweight materials made from coal gasification slags. Quarterly report, December 1, 1995--February 28, 1996
The project scope consists of collecting a 20-ton sample of slag (primary slag), processing it for chart removal, and subjecting it to pyroprocessing to produce expanded slag aggregates of various size gradations and unit weights, ranging from 12 to 50 lb/fg{sup 3}. A second smaller slag sample will be used for confirmatory testing. The expanded slag aggregates will then be tested for their suitability in manufacturing precast concrete products (e.g., masonry blocks and roof tiles) and insulating concrete, first at the laboratory scale and subsequently in commercial manufacturing plants. These products will be evaluated using ASTM and industry test methods. Technical data generated during production and testing of the products will be used to assess the overall technical viability of expanded slag production. In addition, a market assessment will be made based on an evaluation of both the expanded slag aggregates and the final products, and market prices for these products will be established in order to assess the economic viability of these utilization technologies. Relevant cost data for physical and pyroprocessing of slag to produce expanded slag aggregates will be gathered for comparison with (1) the management and disposal costs for slag or similar wastes and (2) production costs …
Date:
December 31, 1996
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Utilization of lightweight materials made from coal gasification slags. Quarterly report, June 1--August 31, 1996
Integrated-gasification combined-cycle (IGCC) technology is an emerging technology that utilizes coal for power generation and production of chemical feedstocks. However, the process generates large amounts of solid waste, consisting of vitrified ash (slag) and some unconverted carbon. In previous projects, Praxis investigated the utilization of ``as-generated`` slags for a wide variety of applications in road construction, cement and concrete production, agricultural applications, and as a landfill material. From these studies, we found that it would be extremely difficult for ``as-generated`` slag to find large-scale acceptance in the marketplace even at no cost because the materials it could replace were abundantly available at very low cost. It was further determined that the unconverted carbon, or char, in the slag is detrimental to its utilization as sand or fine aggregate. It became apparent that a more promising approach would be to develop a variety of value-added products from slag that meet specific industry requirements. This approach was made feasible by the discovery that slag undergoes expansion and forms a lightweight material when subjected to controlled heating in a kiln at temperatures between 1400 and 17000F. These results confirmed the potential for using expanded slag as a substitute for conventional lightweight aggregates (LWA). …
Date:
December 31, 1996
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Utilization of lightweight materials made from coal gasification slags. Quarterly report, March 1--May 31, 1996
Integrated-gasification combined-cycle (IGCC) technology is an emerging technology that utilizes coal for power generation and production of chemical feedstocks. However, the process generates large amounts of solid waste, consisting of vitrified ash (slag) and some unconverted carbon. The major objectives of the subject project are to demonstrate the technical and economic viability of commercial production of lightweight aggregates (LWA) and ultra-lightweight (ULWA) from slag and to test the suitability of these aggregates for various applications. The project goals are to be accomplished in two phases: Phase 1, comprising the production of LWA and ULWA from slag at the large pilot-scale, and Phase 2, which involves commercial evaluation of these aggregates in a number of applications. The following significant events occurred during this reporting period: testing of slag-based lightweight aggregates for roof tile and concrete applications.
Date:
December 31, 1996
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Utilization of low NOx coal combustion by-products. Quarterly report, April 1 - June 30, 1996
This project is studying a beneficiation process to make power plant fly ash a more useful by-product. Accomplishments for this reporting period are presented for the following tasks: laboratory characterization which includes sample collection, material characterization and laboratory testing of ash processing operations; product testing including concrete, concrete block/brick, plastic fillers and activated carbon; and market and economic analysis. Appendix A contains data on fly ash material characterization--major elemental analysis by size.
Date:
December 31, 1996
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Utilization of Low NOx Coal Combustion by-Products. Quarterly Report, January 1 - March 31, 1996
Work performed during the period January 1 through March 31, 1996 is described. Tasks included material characterization of ash; pilot plant testing; product testing for concrete, concrete block/brick, plastic fillers, activated carbon and metal matrix composites; and a market analysis for plastic fillers, activated carbon and carbon black, and market research and development.
Date:
December 31, 1996
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Utilization of low NOx coal combustion by-products. Quarterly report, July 1--September 30, 1996
The objective of this project was to commercialize fly ash beneficiation at various facilities around the country. The paper describes laboratory characterization of fly ash samples, pilot plant testing, product testing, and market and economic analyses. Products include concrete, concrete blocks and bricks, plastic fillers, activated carbon, and metal matrix composites.
Date:
December 31, 1996
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Validation of 1-D transport and sawtooth models for ITER
In this paper the authors describe progress on validating a number of local transport models by comparing their predictions with relevant experimental data from a range of tokamaks in the ITER profile database. This database, the testing procedure and results are discussed. In addition a model for sawtooth oscillations is used to investigate their effect in an ITER plasma with alpha-particles.
Date:
December 31, 1996
Creator:
Connor, J. W.; Turner, M. F.; Attenberger, S. E. & Houlberg, W. A.
Object Type:
Article
System:
The UNT Digital Library
Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, July 1 - September 31, 1996
The vapor pressure correlations that exist at present for coal tars are very crude and they are not considered reliable to even an order of magnitude. This project seeks to address this important gap in the near term by direct measurement of vapor pressures of coal tar fractions, by application of well-established techniques and modifications thereof. The principal objectives of the program are to: (1) obtain data on the vapor pressures and heats of vaporization of tars from a range of ranks of coal; (2) develop correlations based on a minimum set of conveniently measurable characteristics of the tars; and (3) develop equipment that would allow performing such measurements in a reliable, straightforward fashion. During this quarter we have extended the work on measurements of vapor pressures of coal tars, using the continuous Knudsen effusion technique. These results need further analysis and therefore in this report we describe only the general idea behind the technique, and also show some typical results.
Date:
December 31, 1996
Creator:
Suuberg, E.M.; Oja, V. & Lilly, W.D.
Object Type:
Report
System:
The UNT Digital Library
Variability of modal parameters measured on the Alamosa Canyon Bridge
A significant amount of work has been reported in technical literature regarding the use of changes in modal parameters to identify the location and extent of damage in structures. Curiously absent, and critically important to the practical implementation of this work, is an accurate characterization of the natural variability of these modal parameters caused by effects other than damage. To examine this issue, a two-lane, seven-span, composite slab-on-girder bridge near the town of Truth or Consequences in southern New Mexico was tested several times over a period of nine months. Environmental effects common to this location that could potentially produce changes in the measured modal properties include changes in temperature, high winds, and changes to the supporting soil medium. In addition to environmental effects, variabilities in modal testing procedures and data reduction can also cause changes in the identified dynamic properties of the structure. In this paper the natural variability of the frequencies and mode shapes of the Alamosa Canyon bridge that result from changes in time of day when the test was performed, amount of traffic, and environmental conditions will be discussed. Because this bridge has not been in active use throughout the testing period, it is assumed that …
Date:
December 31, 1996
Creator:
Farrar, C.R.; Doebling, S.W.; Cornwell, P.J. & Straser, E.G.
Object Type:
Article
System:
The UNT Digital Library
Variational nodal perturbation calculations using simplified spherical harmonics
The simplified spherical harmonics (SP{sub N}) method has been used as an approximation to the transport equation in a number of situations. Recently, the SP{sub N} method has been formulated within the framework of the variational nodal method (VNM). Implementation in the VARIANT code indicated that for many two and three dimensional problems, near P{sub N} accuracy can be obtained at a fraction of the Cost. Perturbation methods offer additional computational cost reduction for reactor core calculations and are indispensable for performing a variety of calculations including sensitivity studies and the breakdown by components of reactivity worths. Here, we extend the perturbation method developed for the VNM in the full P{sub N} approximation to treat simplified spherical harmonics. The change in reactivity predicted by both first order and exact perturbation theory using the SP{sub N} approximation is demonstrated for a benchmark problem and compared to diffusion and full P{sub N} estimates.
Date:
December 31, 1996
Creator:
Laurin-Kovitz, K.; Palmiotti, G. & Lewis, E.E.
Object Type:
Article
System:
The UNT Digital Library
Velocity and concentration studies of flowing suspensions by nuclear magnetic resonance imaging. Final report, October 7, 1994--October 6, 1996
Nuclear magnetic resonance imaging techniques were developed to study concentrated suspension flows. The tasks completed were: (1) materials selection for imaging of both particle and fluid components, (2) pipe flow measurements, and (3) flows in complex geometries. The partially completed task is the development of rapid imaging techniques by analog compensation of eddy currents, generated by the gradient pulses, and real-time image reconstruction from the data. The best combination of materials found is pharmaceutical beads in silicon oil. Their relaxation times T{sub 1} are sufficiently different to permit imaging the two components separately. The pipe flow experiment used 3 mm, neutrally buoyant, plastic particles, up to 40% by volume, in 80--90W transmission oil flowing in a 5 cm diameter pipe. Distances ranging from 60 cm to 6 m downstream from a commercial mixer was studied. The flow is fully developed at 6 m and the concentration and velocity profiles agree with earlier lower resolution experiments. The eddy current compensation scheme works well for two channels and is being extended to eight channels. The authors have also built a rapid reconstruction hardware that processes and displays images in a fraction of a second. They studied the flow of neutrally buoyant concentrated …
Date:
December 31, 1996
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Verification of the MCNP{trademark} perturbation technique
Over the last few decades, users of the Monte Carlo radiation transport code MCNP have expressed the need for a perturbation capability. The perturbation technique chosen for inclusion as a standard feature in future releases of MCNP is described here. This new MCNP feature will provide the radiation transport analyst with a powerful tool for predicting the effect of multiple perturbations within a single run.
Date:
December 31, 1996
Creator:
McKinney, G. W. & Iverson, J. L.
Object Type:
Article
System:
The UNT Digital Library
Verification of three dimensional charge transport simulations using ion microbeams
Optically targeted, ion microbeams provide a useful means of exposing individual structures within an integrated circuit to ionizing radiation. With this tool, calibrated, low damage, charge collection spectra can be measured from specific circuit structures without preceding ion damage to the structure or surrounding circuitry. This paper presents comparisons of calibrated, low damage, ion microbeam- based charge collection measurements and three-dimensional, charge transport simulations of charge collection for isolated n- and p- channel field effect transistors under conducting and non-conducting bias conditions.
Date:
December 31, 1996
Creator:
Horn, K.M.; Dodd, P.E.; Breese, M.B.H. & Doyle, B.L.
Object Type:
Article
System:
The UNT Digital Library
Vertical-axis wind turbines -- The current status of an old technology
Vertical-axis wind turbine technology is not well understood, even though the earliest wind machines rotated about a vertical axis. The operating environment of a vertical-axis wind turbine is quite complex, but detailed analysis capabilities have been developed and verified over the last 30 years. Although vertical-axis technology has not been widely commercialized, it exhibits both advantages and disadvantages compared to horizontal-axis technology, and in some applications, it appears to offer significant advantages.
Date:
December 31, 1996
Creator:
Berg, D.E.
Object Type:
Article
System:
The UNT Digital Library
Very large hadron colliders
Issues pertaining to the next generation (post LHC) Hadron Colliders have been addressed over the past several years at workshops at Indiana, Indianapolis, and more recently at Snowmass. Although no attempt has been made to produce a detailed parameter set, most work has addressed energies in the range of 80-100 TeV centre-of-mass with a peak luminosity of 10{sup 34} cm{sup -2} s{sup -1}. This is sufficient to illuminate the potential problems associated with this class of machines. There have been two distinct design concepts that have been examined; the low-field and high-field options. It is significant to note that while an SSC-like approach to access this energy range is technically feasible the cost of such a device is deemed prohibitive. There is general agreement that new technologies are necessary to achieve a cost breakthrough and as such that the dominant technical challenges for the future are driven by cost considerations, unlike linear or muon colliders, where cost is merely important the organizing committee at Snowmass challenged the sub-group with a cost goal of $50M per Tev, and although neither option is sufficiently mature at this point to attempt any meaningful cost estimate, this figure gives an indication of the potential …
Date:
December 31, 1996
Creator:
Harrison, M.
Object Type:
Article
System:
The UNT Digital Library
Vibration modal analysis using all-optical photorefractive processing
A new experimental method for vibration modal analysis based on all- optical photorefractive processing is presented. The method utilizes an optical lock-in approach to measure phase variations in light scattered from optically rough, continuously vibrating surfaces. In this four-wave mixing technique, all-optical processing refers to mixing the object beam containing the frequency modulation due to vibration with a single frequency modulated pump beam in the photorefractive medium that processes the modulated signals. This allows for simple detection of the conjugate wavefront image at a CCD. The conjugate intensity is shown to be a function of the first-order ordinary Bessel function and linearly dependent on the vibration displacement induced phase. Furthermore, the results demonstrate the unique capabilities of the optical lock-in vibration detection technique to measure vibration signals with very narrow bandwidth (< 1 Hz) and high displacement sensitivity (sub-Angstrom). This narrow bandwidth detection can be achieved over a wide frequency range from the photorefractive response limit to the reciprocal of the photoinduced carrier recombination time. The technique is applied to determine the modal characteristics of a rigidly clamped circular disc from 10 kHz to 100 kHz.
Date:
December 31, 1996
Creator:
Hale, T. & Telschow, K.
Object Type:
Article
System:
The UNT Digital Library
Viewing Systems for Large Underground Storage Tanks.
Specialized remote video systems have been successfully developed and deployed in a number of large radiological Underground Storage Tanks (USTs)that tolerate the hostile tank interior, while providing high resolution video to a remotely located operator. The deployment is through 100 mm (4 in) tank openings, while incorporating full video functions of the camera, lights, and zoom lens. The usage of remote video minimizes the potential for personnel exposure to radiological and hazardous conditions, and maximizes the quality of the visual data used to assess the interior conditions of both tank and contents. The robustness of this type of remote system has a direct effect on the potential for radiological exposure that personnel may encounter. The USTs typical of the Savannah River and Hanford Department Of Energy - (DOE) sites are typically 4.5 million liter (1.2 million gal) units under earth. or concrete overburden with limited openings to the surface. The interior is both highly contaminated and radioactive with a wide variety of nuclear processing waste material. Some of the tanks are -flammable rated -to Class 1, Division 1,and personnel presence at or near the openings should be minimized. The interior of these USTs must be assessed periodically as part of …
Date:
December 31, 1996
Creator:
Heckendorn, F. M.; Robinson, C. W. & Anderson, E. K.
Object Type:
Article
System:
The UNT Digital Library
A virtual universe utilizing haptic display
This paper summarizes a virtual reality universe application in which a user can travel between four virtual worlds through the use of haptic buttons. Each of the worlds demonstrates different aspects of haptic rendering which together create a wide base for force feedback effects. Specifics of the rendering algorithms will be discussed along with possible uses and modifications for other real-life applications.
Date:
December 31, 1996
Creator:
Anderson, T.
Object Type:
Article
System:
The UNT Digital Library
Visualization of monoamine oxidase in human brain
Monoamine oxidase is a flavin enzyme which exists in two subtypes, MAO A and MAO B. In human brain MAO B predominates and is largely compartmentalized in cell bodies of serotonergic neurons and glia. Regional distribution of MAO B was determined by positron computed tomography with volunteers after the administration of deuterium substituted [11C]L-deprenyl. The basal ganglia and thalamus exhibited the greatest concentrations of MAO B with intermediate levels in the frontal cortex and cingulate gyrus while lowest levels were observed in the parietal and temporal cortices and cerebellum. We observed that brain MAO B increases with are in health normal subjects, however the increases were generally smaller than those revealed with post-mortem studies.
Date:
December 31, 1996
Creator:
Fowler, J. S.; Volkow, N. D.; Wang, G. J.; Pappas, N.; Shea, C.; MacGregor, R. R. et al.
Object Type:
Article
System:
The UNT Digital Library