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135,844 Matching Results
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Fractional processes and nuclear disassembly in very-heavy-ion collisions in the Fermi energy regime
Exclusive measurements of charged products and neutrons were performed for the reactions {sup 197}Au + (29 MeV/u) {sup 208}Pb and {sup 209}Bi + (28.2 MeV/u) {sup 136}Xe. The multiplicities of neutrons and charged particles are found to indicate collision impact parameters with different sensitivities. Characteristic correlations observed between massive products and light particles suggest the dominance of the damped-reaction mechanism in the Fermi energy domain. For central collisions, massive fragments are no longer observed, and a considerable fraction of the mass of the system is found disassembled into light particles and clusters. 75 refs., 19 figs.
Date:
January 1, 1991
Creator:
Schroeder, W.U.
Object Type:
Article
System:
The UNT Digital Library
Vibration considerations in the design of the Advanced Photon Source at Argonne National Laboratory
The Advanced Photon Source (APS), a new synchrotron radiation facility being built at Argonne National Laboratory, will provide the world's most brilliant X-ray beams for research in a wide range of technical fields. Successful operation of the APS requires an extremely stable positron closed orbit. Vibration of the storage ring quadrupole magnets, even in the submicron range, can lead to distortion of the positron closed orbit and to potentially unacceptable beam emittance growth, which results in degraded performance. This paper presents an overview of the technical approach used to minimize vibration response, beginning at the conceptual stage, through design and construction, and on to successful operation. Acceptance criteria relating to maximum allowable quadrupole magnet vibration are discussed. Soil properties are used to determine resonant frequencies of foundations and to predict attenuation characteristics. Two sources are considered to have the potential to excite the foundation: far-field sources, which are produced external to the facility, and near-field sources, which are produced within the facility. Measurements of ambient ground motion, monitored to determine far- field excitation, are presented. Ambient vibration was measured at several operating facilities within Argonne to gain insight on typical near-field excitation sources. Discussion covers the dynamic response characteristics of …
Date:
January 1, 1991
Creator:
Jendrzejczyk, J.A. & Wambsganss, M.W.
Object Type:
Article
System:
The UNT Digital Library
High temperature ceramic membrane reactors for coal liquid upgrading
In this project we will study a novel process concept, i.e., the use of ceramic membrane reactors in upgrading of coal model compounds and coal derived liquids. In general terms, the USC research team is responsible for constructing and operating the membrane reactor apparatus and for testing various inorganic membranes for the upgrading of coal derived asphaltenes and coal model compounds. The USC effort will involve the principal investigator of this project and two graduate research assistants. The ALCOA team is responsible for the preparation of the inorganic membranes, for construction and testing of the ceramic membrane modules, and for measurement of their transport properties. The ALCOA research effort will involve Dr. Paul K. T. Liu, who is the project manager of the ALCOA research team, an engineer and a technician. UNOCAL's contribution will be limited to overall technical assistance in catalyst preparation and the operation of the laboratory upgrading membrane reactor and for analytical back-up and expertise in oil analysis and materials characterization. UNOCAL is a no-cost contractor but will be involved in all aspects of the project, as deemed appropriate.
Date:
January 1, 1992
Creator:
Tsotsis, T.T.
Object Type:
Report
System:
The UNT Digital Library
Rapid quenching of molten lithium-aluminum jets in water under loss-of-control-rod-cooling conditions
A series of fifteen tests were performed to investigate the thermal interactions between molten LiAl control rod material and water under conditions prototypic of the loss-of-control-rod-cooling (LCRC) accident scenario. The experimental parameters such as melt mass, stream diameter, melt temperature and flowrate, water depth and water temperature were controlled or varied to agree with analytically determined conditions, thus insuring prototypicality of the experiments and applicability of the results. Experiments were performed in an actual Q-septifoil with web insert; the test section was one meter tall. Natural triggers were investigated in selected tests, to evaluate the self-triggering potential of this system. The self-triggering mechanisms that were investigated were thermal stratification of the water pool, two-phase flow in the water pool, and simultaneous drop of a control rod in parallel channel. Only benign interactions were observed during these tests with some evidence of pressurization in the tests with deepest and hottest water pools. There was no evidence of any explosive interactions in any of the tests, even those with natural triggers. The molten LiAl jets was found to undergo jet breakup and fragmentation; in some cases the debris hung up in the web, in other cases the debris settled into a loose …
Date:
January 1, 1992
Creator:
Greene, G. A.; Finfrock, C. C.; Schwarz, C. E.; Allison, D. K. & Hyder, M. L.
Object Type:
Report
System:
The UNT Digital Library
Thermodynamics of natural and industrial waters
The most effective general formulations of thermodynamic equations for multicomponent aqueous solutions are discussed with respect to various ranges of temperature, pressure and composition with emphasis on solutes important in natural or industrial waters. A familiar equation in molality and in excess Gibbs energy is very successful up to 300{degree}C and ionic strength 6 mol{center dot}kg{sup {minus}1}, and can often be extended to 350{degree}C or above at high pressure and in favorable cases to ionic strength 12 or even 20. Alternate methods valid to higher solute compositions, even to pure fused salts, are described. A more difficult situation arises near the critical point of water where the compressibility becomes infinite and a Helmholtz energy basis must be adopted. Existing equations for this range and still higher temperatures and pressures are considered and possible improvements discussed. 85 refs., 13 figs., 3 tabs.
Date:
August 1, 1991
Creator:
Pitzer, K.S.
Object Type:
Article
System:
The UNT Digital Library
An organizational survey of the Strategic Petroleum Reserve. [Organizational survey in preparation for an upcoming Tiger Team Assessment]
At the request of the management of the Strategic Petroleum Reserve (SPR), an Organizational Survey (OS), identical to the one that has been used prior to Tiger Team Assessments at other Department Energy facilities, was administered at SPR independent of a Tiger Team Assessment. The OS measured employees' opinions on subjects such as organizational culture, communication, commitment, group cohesion, coordination, safety, environmental issues, and job satisfaction. The result of this work was a quantitative measure of these variables at the SPR site. SPR management intends to utilize these results in their self-assessment process in preparation for an upcoming Tiger Team Assessment. This report presents these results and discusses their interpretation.
Date:
January 1, 1992
Creator:
Shurberg, D.A. & Haber, S.B.
Object Type:
Report
System:
The UNT Digital Library
Aging Aircraft NDI Development and Demonstration Center (AANC): An overview
A major center with emphasis on validation of nondestructive inspection techniques for aging aircraft, the Aging Aircraft NDI Development and Demonstration Center (AANC), has been funded by the FAA at Sandia National Laboratories. The Center has been assigned specific tasks in developing techniques for the nondestructive inspection of static engine parts, assessing inspection reliability (POD experiments), developing test beds for nondestructive inspection validation, maintaining a FAA library of characterized aircraft structural test specimens, and leasing a hangar to house a high flight cycle transport aircraft for use as a full scale test bed. 3 refs.
Date:
January 1, 1991
Creator:
Walter, P. L.
Object Type:
Article
System:
The UNT Digital Library
The neutrinos in muon decay
We review the available information on the identity of the neutrino states emitted in muon decay, and discuss the exotic decay {mu}{sup +} {yields} e{sup +} {bar {nu}}{sub e}{nu}{sub {mu}}. 22 refs.
Date:
October 21, 1991
Creator:
Herczeg, P.
Object Type:
Article
System:
The UNT Digital Library
Research in theoretical nuclear physics
The work done during the past year covers three separate areas, low energy nuclear reactions intermediate energy physics, and nuclear structure studies. This manuscript summarizes our achievements made in these three areas.
Date:
October 1, 1991
Creator:
Udagawa, T.
Object Type:
Report
System:
The UNT Digital Library
Theory of ordering transformations in metals and minerals
This dissertation presents an investigation of ordering in FCC based systems using the pair potential approximation in the ground state and mean field limits. The theoretical approach is used to explain the occurrence of observed equilibrium phases and characteristics of thermodynamic instabilities, in particular, spinodal ordering and decomposition. It is shown that the stability of non-integer domain sizes in long period superstructures such as Al{sub 3}Ti and Ag{sub 3}Mg may result from the tendency of a system to reduce the number of non-dominant ordering waves, thus producing domain sizes that have rational fraction form n/m. This conclusion is used to explain the domain size stability with respect to variations in temperature and electron concentration. The cation ordering in the precipitate phases in calcite and dolomite is analyzed by analogy with ordering in FCC based metals. The ordered phases in calcite and dolomite are shown to be consistent with pair potential minima at {l brace}100{r brace} and {l brace}1/2, 1/2, 1/2{r brace} positions in reciprocal space respectively. 32 refs., 6 figs.
Date:
July 1, 1991
Creator:
Lindsey, Timothy Francis
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Costs and benefits of automotive fuel economy improvement: A partial analysis
This paper is an exercise in estimating the costs and benefits of technology-based fuel economy improvements for automobiles and light trucks. Benefits quantified include vehicle cots, fuel savings, consumer's surplus effects, the effect of reduced weight on vehicle safety, impacts on emissions of CO{sub 2} and criteria pollutants, world oil market and energy security benefits, and the transfer of wealth from US consumes to oil producers. A vehicle stock model is used to capture sales, scrappage, and vehicle use effects under three fuel price scenarios. Three alternative fuel economy levels for 2001 are considered, ranging from 32.9 to 36.5 MPG for cars and 24.2 to 27.5 MPG for light trucks. Fuel economy improvements of this size are probably cost-effective. The size of the benefit, and whether there is a benefit, strongly depends on the financial costs of fuel economy improvement and judgments about the values of energy security, emissions, safety, etc. Three sets of values for eight parameters are used to define the sensitivity of costs and benefits to key assumptions. The net present social value (1989$) of costs and benefits ranges from a cost of $11 billion to a benefit of $286 billion. The critical parameters being the discount …
Date:
March 1, 1992
Creator:
Greene, D.L. (Oak Ridge National Lab., TN (United States)) & Duleep, K.G. (Energy and Environmental Analysis, Inc., Arlington, VA (United States))
Object Type:
Report
System:
The UNT Digital Library
FLOWTRAN benchmarking with onset of flow instability data from 1988 Columbia University single-tube OFI experiment
Benchmarking FLOWTRAN, Version 16.2, with an Onset of Significant Voiding (OSV) criterion against measured Onset of Flow Instability (OFI) data from the 1988--89 Columbia University downflow tests has shown that FLOWTRAN with OSV is a conservative OFI predictor. Calculated limiting flow rates based on the Savannah River Site (SRS) OSV criterion were always higher than the measured flow rates at OFI. This work supplements recent FLOWTRAN benchmarking against 1963 downflow tests at Columbia University and 1988 downflow tests at the Heat Transfer Laboratory. These studies provide confidence that using FLOWTRAN with an OSV based criterion for SRS reactor limits analyses will generate operating limits that are conservative with respect to OFI, the criterion selected to prevent fuel damage.
Date:
June 1, 1990
Creator:
Chen, K.; Paul, P. K. & Barbour, K. L.
Object Type:
Report
System:
The UNT Digital Library
Predicting aquatic macrophyte modeling of a new freshwater lake using remote sensing
Par Pond and L Lake are reservoirs on the Savannah River Site in South Carolina. Beds of aquatic macrophytes (primarily cattail and waterlilies) exist in Par Pond and are now beginning to develop in L Lake. Biophysical knowledge about Par Pond was used to develop environmental constraint criteria' to predict the future spatial distribution of aquatic macrophytes in L Lake. The L Lake biophysical data were placed in a 5 {times} 5 m raster geographic information system (GIS) and analyzed using Boolean logic. Areas in L Lake which were {le}4 m in depth, {le}10% slope, had a fetch of {le}500 m, and on suitable soil were identified. The final GIS model predicted the spatial distribution of 37.30 ha of aquatic macrophytes which met the environmental constraint criteria (cattails = 12.29 ha and waterlilies = 25.01 ha).
Date:
January 1, 1992
Creator:
Jensen, J. R.; Narumalani, S.; Weatherbee, O.; Morris, K. S., Jr. & Mackey, H. E., Jr.
Object Type:
Article
System:
The UNT Digital Library
Dependence of secondary ion emission from organic material on the energy loss of the impacting heavy ion
Samples of the amino acid valine were irradiated by 2.5 MeV-Ar, 0.8 MeV-Kr and 1.0 MeV Xe beams from the Argonne Dynamitron accelerator in order to study the energy distributions of ejected secondary ions. For Kr and Xe the nuclear stopping power exceeded the electronic stopping power by a factor 2 or 3, respectively, but the functional shape of the energy distributions and the mean ejection energies (0.9--1.4 eV) indicated that the molecular ions (M{plus minus}H){sup {plus minus}} are desorbed by an electronic sputter process. Contributions of atomic collision cascades were observed for the H{sup {minus}} ion. In the second part of the article, the overall dependence of molecular ion yields on the electronic energy loss is discussed in the framework of recent desorption models and the structure of the nuclear track.
Date:
January 1, 1991
Creator:
Hunt, J.E. (Argonne National Lab., IL (United States)) & Wien, K. (Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik)
Object Type:
Article
System:
The UNT Digital Library
Molecular Sieve Regeneration System for assaying HTO from detritiation systems
A Molecular Sieve Regeneration System (MSRS) is being added to the existing Tritium Waste Treatment system (TWT) within the Tritium Systems Test Assembly (TSTA) at the Los Alamos National Laboratory. This system is an upgrade to the TWT to provide accurate measurements of the liquid waste generated from this system. Within the TWT, hydrogen isotopes are removed from the effluent gas stream by the catalytic conversion to water and the subsequent removal of water by molecular sieve trapping prior to the release to the environment. Within the TWT and similar systems, molecular sieve regeneration is required to rejuvenate the beds. The major difference of the MSRS and other regeneration systems is the capability of direct assay of long-term storage waste containers. This is accomplished with loop-flow regeneration, water collection, and tritiated water assay by scintillation and calorimetric techniques. This paper describes the MSRS in detail and how it is interfaced with the Tritium Waste Treatment system.
Date:
January 1, 1992
Creator:
Nasise, J.E.; Anderson, J.L. (Los Alamos National Lab., NM (United States)) & Naruse, Y. (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan))
Object Type:
Article
System:
The UNT Digital Library
(NLUF user-application of a high-density gas laser target to the physics x-ray lasers and coronal plasmas)
None
Date:
March 13, 1992
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Magnetic fusion with high energy self-colliding ion beams
Field-reversed configurations of energetic large orbit ions with neutralizing electrons have been proposed as the basis of a fusion reactor. Vlasov equilibria consisting of a ring or an annulus have been investigated. A stability analysis has been carried out for a long thin layer of energetic ions in a low density background plasma. There is a growing body of experimental evidence from tokamaks that energetic ions slow down and diffuse in accordance with classical theory in the presence of large non-thermal fluctuations and anomalous transport of low energy (10 keV) ions. Provided that major instabilities are under control, it seems likely that the design of a reactor featuring energetic self-colliding ion beams can be based on classical theory. In this case a confinement system that is much better than a tokamak is possible. Several methods are described for creating field reversed configurations with intense neutralized ion beams.
Date:
June 1, 1992
Creator:
Rostoker, N.; Wessel, F. (California Univ., Irvine, CA (United States)); Maglich, B. (Advanced Physics Corp., Irvine, CA (United States)) & Fisher, A. (Naval Research Lab., Washington, DC (United States))
Object Type:
Article
System:
The UNT Digital Library
A comparison of spanwise aerodynamic loads estimated from measured bending moments versus direct pressure measurements on horizontal axis wind turbine blades
Two methods can be used to determine aerodynamic loads on a rotating wind turbine blade. The first is to make direct pressure measurements on the blade surface. This is a difficult process requiring costly pressure instrumentation. The second method uses measured flap bending moments in conjunction with analytical techniques to estimate airloads. This method, called ALEST, was originally developed for use on helicopter rotors and was modified for use on horizontal axis wind turbine blades. Estimating airloads using flap bending moments in much simpler and less costly because measurements can be made with conventional strain gages and equipment. This paper presents results of airload estimates obtained using both methods under a variety of operating conditions. Insights on the limitations and usefulness of the ALEST bending moment technique are also included. 10 refs., 6 figs.
Date:
October 1, 1991
Creator:
Simms, D A & Butterfield, C P
Object Type:
Article
System:
The UNT Digital Library
Mechanism of (n,. gamma. ) reaction at low neutron energies
We discuss the interplay between direct capture, valence capture, and compound-nuclear capture in attempting to explain the vast amount of capture data for light-mass nuclei. 13 refs.
Date:
January 1, 1991
Creator:
Raman, S. (Oak Ridge National Lab., TN (United States)) & Lynn, J.E. (Los Alamos National Lab., NM (United States))
Object Type:
Article
System:
The UNT Digital Library
Applications of mesoscopic physics
This report discusses the following topics: Acoustical nondestructive evaluation of heterogeneous materials in the multiple scattering regime. Classical and quantum superdiffusion in a time-dependent random potential. Negative Magnetoresistance in Variable Range Hopping Conduction. Reproducible Conductance Fluctuations in Macroscopic Anderson Insulators. Feasibility of far-infared lasers using multiple semiconductor quantum wells.
Date:
January 1, 1992
Creator:
Feng, Shechao.
Object Type:
Report
System:
The UNT Digital Library
Evaluation of proposed designs for streamflow monitoring structures at waste disposal sites
Design of small surface water monitoring stations associated with waste sites requires an approach that balances several problems. The monitoring site must have a capacity for a wide range of flows, allow accurate measurements over the full performance range, minimize effects from accumulation of contaminated sediments, and minimize costs of construction and operation. Selecting a station design that takes these factors into consideration can be done systematically through use of formal decision analysis. The paper discusses the effectiveness of various hydraulic structures as flumes and weirs to monitor stream flow and drainage. The process has produced the most viable alternative designs and yielded fully documented guidelines for designing new stations as they are needed. 7 refs., 6 figs., 3 tabs.
Date:
January 1, 1991
Creator:
Clapp, R. B.; Borders, D. M.; Tardiff, M. F. & Huff, D. D.
Object Type:
Article
System:
The UNT Digital Library
H-Area Seepage Basins
During the third quarter of 1990 the wells which make up the H-Area Seepage Basins (H-HWMF) monitoring network were sampled. Laboratory analyses were performed to measure levels of hazardous constituents, indicator parameters, tritium, nonvolatile beta, and gross alpha. A Gas Chromatograph Mass Spectrometer (GCMS) scan was performed on all wells sampled to determine any hazardous organic constituents present in the groundwater. The primary contaminants observed at wells monitoring the H-Area Seepage Basins are tritium, nitrate, mercury, gross alpha, nonvolatile beta, trichloroethylene (TCE), tetrachloroethylene, lead, cadmium, arsenic, and total radium.
Date:
December 1, 1990
Creator:
Stejskal, G.
Object Type:
Report
System:
The UNT Digital Library
FY 90 annual research plan
The National Institute for Petroleum and Energy Research (NIPER) was established by the DOE to perform contract research for government and industrial clients. The emphasis of the DOE program is immediate near- and mid-term concerns of domestic oil and gas producibility. Its primary purpose is to improve the fundamental understanding of domestic oil and gas resources and the chemical, physical, and biological phenomena that govern the occurrence and recovery of these resources in addition to their associated environmental issues. The near-term objective of the DOE program is to maintain access to resources presently being produced in domestic oil and gas fields, and to decrease the rate of decline of domestic production. NIPER projects in chemical flooding, gas injection, steam injection, and microbial EOR address near-term concerns of domestic oil production. Further, problems associated with the utilization of heavier fossil feedstocks are being addressed. The mid-term objective of the DOE program is to maximize the recovery efficiency of discovered oil and gas through improved understanding of the resource and to develop advanced extraction and instrumentation techniques. The objective also emphasizes an expanded understanding of the environment. NIPER projects dealing with the quantification of reservoir heterogeneities, pore structure analysis, and fluid flow …
Date:
January 1, 1990
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Milliwatt Generator Project
This report covers progress on the Milliwatt Generator Project from April 1986 through March 1988. Activities included fuel processing and characterization, production of heat sources, fabrication of pressure-burst test units, compatibility studies, impact testing, and examination of surveillance units. The major task of the Los Alamos Milliwatt Generator Project is to fabricate MC2893A heat sources (4.0 W) for MC2730A radioisotope thermoelectric generators (RTGS) and MC3599 heat sources (4.5 W) for MC3500 RTGs. The MWG Project interfaces with the following contractors: Sandia National Laboratories, Albuquerque (designer); E.I. du Pont de Nemours and Co. (Inc.), Savannah River Plant (fuel); Monsanto Research Corporation, Mound Facility (metal hardware); and General Electric Company, Neutron Devices Department (RTGs). In addition to MWG fabrication activities, Los Alamos is involved in (1) fabrication of pressure-burst test units, (2) compatibility testing and evaluation, (3) examination of surveillance units, and (4) impact testing and subsequent examination of compatibility and surveillance units.
Date:
May 1, 1992
Creator:
Latimer, T.W. & Rinehart, G.H.
Object Type:
Report
System:
The UNT Digital Library