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9,953
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564
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427
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105
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75
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53
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378
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48
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11,315 Matching Results
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Development of a low intensity current monitor system
This report documents the development of a current transformer system used to measure pulsed ion beam currents with a wide dynamic intensity range (nA to mA, and factor of 10{sup 6}). Peak beam currents at the LAMPF accelerator typically range from 100 to nA to 40 mA with pulse widths varying from 30 to 1000 {mu}s. Signal conditioning of the peak current output provides an average current readout with a range of 1 nA to 2 mA, noise of approximately {plus minus}0.5 nA, and accuracy of {plus minus}0.1%. Since the system has proved stable and highly reliable, calibration is performed yearly. The prototype unit was built in 1985 and the final production unit was completed in early 1989. 5 refs., 14 figs.
Date:
January 1, 1991
Creator:
Gallegos, F.R.
Object Type:
Article
System:
The UNT Digital Library
Liquefaction of coals using ultra-fine particle, unsupported catalysts: In situ generation by rapid expansion of supercritical fluid solutions
The program objective is to generate ultra-fine catalyst particles (20 to 400 {Angstrom} in size) and quantify their potential for improving coal dissolution in the solubilization stage of two-stage catalytic-catalytic liquefaction systems. In the first quarterly report for this program the concept behind our approach was detailed, the structure of the program was presented, key technical issues were identified, preliminary designs were outlined, and technical progress was discussed. All progress made during the second quarter of this program related to experiment design of the proposed supercritical expansion technique for generating ultra-fine, iron compound, catalyst particles. This second quarterly report, therefore, presents descriptions of the final designs for most system components; diagnostic approaches and designs for determining particles size and size distributions, and the composition of the pre-expansion supercritical solution; and the overall technique progress made during this reporting period. 6 refs., 15 figs., 1 tab.
Date:
September 1, 1991
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Impact of Nonequilibrium Particle Temperature Considerations on Seeded Coal Combustion Plasma Properties
This past quarter ending 12/30/91, the linear MHD channel simulation model has not only been completely specified but also fully modified to incorporate considerations for nonequilibrium particle temperatures. Testing of the modified model with the initial values from the first submodel (Richter's combustion zone model) and evaluation of the non-equilibrium particle temperature effect on the overall MHD performance is being held up. Reasons for the holdup is the lack of adequate response from Dr. Richter on questions about his nonequilibrium particle temperature model. These questions relate to our insistence to know precisely how the model works and also some review of the source code to ascertain that it is synchronization with our overall analytical development. We have decided to generate initial generator inlet particle parameter values by modifying the CEC code to provide particle parameter values.
Date:
January 1, 1991
Creator:
Oni, A. A.
Object Type:
Report
System:
The UNT Digital Library
Potential effects of maternal contribution on egg and larva population dynamics of striped bass: Integrated individual-based model and directed field sampling
We have used a bioenergetically-driven, individual-based model (IBM) of striped bass as a framework for synthesizing available information on population biology and quantifying, in a relative sense, factors that potentially affect year class success. The IBM has been configured to simulate environmental conditions experienced by several striped bass populations; i.e., in the Potomac River, MD; in Hudson River, NY; in the Santee-Cooper River System, SC, and; in the San Joaquin-Sacramento River System CA. These sites represent extremes in the geographic distribution and thus, environmental variability of striped bass spawning. At each location, data describing the physio-chemical and biological characteristics of the spawning population and nursery area are being collected and synthesized by means of a prioritized, directed field sampling program that is organized by the individual-based recruitment model. Here, we employ the striped bass IBM configured for the Potomac River, MD from spawning into the larval period to evaluate the potential for maternal contribution to affect larva survival and growth. Model simulations in which the size distribution and spawning day of females are altered indicate that larva survival is enhanced (3.3-fold increase) when a high fraction of females in the spawning population are large. Larva stage duration also is less …
Date:
January 1, 1991
Creator:
Cowan, J.H., Jr. (Maryland Univ., Solomons, MD (United States). Chesapeake Biological Lab.) & Rose, K.A. (Oak Ridge National Lab., TN (United States))
Object Type:
Article
System:
The UNT Digital Library
Utility FGD survey, January--December 1988
This report summarizes the status of Flue Gas Desulfurization (FGD) technology as of December 1988. It highlights the status of the electric utility power industry, projected growth of coal-fired power generation, and the current status and future trends in FGD application. Also discussed is the implementation status of other control technologies such as fluidized bed boilers, which utilities may opt for instead of FGD systems. 15 refs., 2 figs., 10 tabs.
Date:
September 1, 1991
Creator:
Hance, S.L.; McKibben, R.S. & Jones, F.M. (IT Corp., Cincinnati, OH (United States))
Object Type:
Report
System:
The UNT Digital Library
Inexpensive cross-flow hydropower turbine at Arbuckle Mountain Hydroelectric Project
This report documents the first three and half years of operation and maintenance on the Arbuckle Mountain Hydroelectric Project. Located on a flashy mountain stream in northern California, the project was designed, built and tested through a Cooperative Agreement between the US DOE and OTT Engineering, Inc. (OTT). The purpose of the Agreement is to build and intensively test an inexpensive American-made cross-flow turbine and to provide information to the DOE on the cost, efficiency, operation, and maintenance of the unit. It requires that OTT document for DOE a summary of the complete operating statistics, operation and maintenance cost, and revenues from power sales for a two-year operating period. Several unique events occurred between the initial start-up (December 1986) and the beginning of the 1989 generation season (October 1988) that delayed the first year's full operation and provided unique information for a demonstration project of this type. Accordingly, this report will discuss certain major problems experienced with the design, operation and maintenance, and energy production, as well as the operation and maintenance costs and value of the power produced for the first three and half years of operation. 9 figs., 2 tabs.
Date:
July 1, 1991
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
The interpretation of reflectometry measurements of plasma fluctuations
Wave reflections from density fluctuations with magnitudes and frequencies typical of drift waves have been investigated. Both drift waves and the reflected phase and amplitude depend on the density gradient scale length, and this common feature implies that both the angular deviation of a normally propagating wave and the phase change on reflection are of order unity. Thus the surface will always appear rough'' and amplitude variations will always be large. For smaller amplitude waves numerical solutions of the one dimensional full wave equation for the propagation near cutoff frequencies has been used to show how to interpret reflectometry measurements. For density perturbations with wavelengths near the density scale length, the external fluctuating phase can be simply interpreted in terms of a fluctuating density near the cutoff layer. However, the amplitude of the phase response falls substantially as the fluctuation wavelength, {Lambda}, approaches the free space wavelength of the reflected wave, {lambda}{sub o}, and the location of the maximum response moves out in front of the cutoff layer following the wave matching condition k{sub {Lambda}} = 2k {approx} 2{eta}(x)k{sub 0}. Similarly, correlation measurements of density fluctuations from probe waves of different wavelengths are shown to be limited to about four …
Date:
October 1, 1991
Creator:
Bretz, N.
Object Type:
Report
System:
The UNT Digital Library
Thermodynamic model for calorimetric and phase coexistence properties of coal derived fluids
On September 1, 1989 work was initiated on a project to extend the available vapor-liquid equilibrium (VLE) model for coal fluids to allow satisfactory predictions of excess enthalpies of coal liquids at high pressures. The available vapor liquid equilibrium model was developed with support from previous grant from DOE-PETC (Grant no. DE-FG22-89PC90541). The current project also involves measurement of some model compound VLE data and chromatographic characterization of coal liquids for distribution of heteroatoms. A computational thermodynamic model for VLE, excess enthalpies and heat capacities of coal derived liquids has been developed. The model uses the modified UNIFAC correlation for the liquid phase. Some unavailable UNIFAC interactions parameters have been regressed from experimental VLE and excess enthalpy data. The computations are carried out using the method of continuous thermodynamics. Mode is used to derive interesting conclusions on the effect of oxygen, nitrogen, and sulfur heteroatoms on the thermodynamic properties of coal liquids. When compared with limited experimental data available for coal liquids the model shows good agreement. Some progress has been made on binary VLE measurements and size exclusion chromatography of coal liquids.
Date:
October 1, 1991
Creator:
Kabadi, V. N.
Object Type:
Report
System:
The UNT Digital Library
CW 100MW microwave power transfer in space
A proposal is made for high-power microwave transfer in space. The concept consists in a microwave power station integrating a multistage microwave free-electron laser and asymmetric dual-reflector system. Its use in space is discussed. 9 refs., 2 figs., 1 tab.
Date:
January 1, 1991
Creator:
Takayama, K. (Houston Univ., TX (United States). Inst. for Beam Particle Dynamics National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan) Texas Accelerator Center, The Woodlands, TX (United States)); Hiramatsu, S. (National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)) & Shiho, M. (Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan))
Object Type:
Article
System:
The UNT Digital Library
Utilization of coal-water fuels in fire-tube boilers
This project is a demonstration for firing coal-water slurry in a fire-tube boiler. It includes design, installation, and demonstration of the slurry firing equipment in a fire-tube boiler at the University of Alabama in Tuscaloosa. The project will be funded by the US Department of Energy with cost sharing from Jim Walter Resources and the University of Alabama. Energy and Environmental Research Corporation is the prime contractor responsible for all respects of the project. The specific objective of this contract is to demonstrate the potential for coal-water fuels to be burned effectively in fire-tube boiler designed for oil or gas. When the results of this project combined with the results of the water-tube slurry testing, a broad data base will exist that will provide valuable information for the retrofit of future boilers. 1 tab.
Date:
January 1, 1991
Creator:
Sommer, T. & Melick, T.
Object Type:
Report
System:
The UNT Digital Library
Optical design and performance of the X25 hybrid wiggler beam line at the NSLS
The X25 beam line at the National Synchrotron Light Source (NSLS) began full-power commissioning in 1990. It extracts radiation from a 27 pole hybrid wiggler, which produces up to 1.8 kW of total power with a peak horizontal density of 450 W/mrad and critical energy of 4.6 keV. The design and performance of the beam line optics are described, in particular the cooling of the first monochromator crystal. 28 refs., 5 figs.
Date:
January 1, 1991
Creator:
Berman, L. E.; Hastings, J. B.; Oversluizen, T. & Woodle, M.
Object Type:
Article
System:
The UNT Digital Library
The International Coal Statistics Data Base program maintenance guide
The International Coal Statistics Data Base (ICSD) is a microcomputer-based system which contains information related to international coal trade. This includes coal production, consumption, imports and exports information. The ICSD is a secondary data base, meaning that information contained therein is derived entirely from other primary sources. It uses dBase III+ and Lotus 1-2-3 to locate, report and display data. The system is used for analysis in preparing the Annual Prospects for World Coal Trade (DOE/EIA-0363) publication. The ICSD system is menu driven and also permits the user who is familiar with dBase and Lotus operations to leave the menu structure to perform independent queries. Documentation for the ICSD consists of three manuals -- the User's Guide, the Operations Manual, and the Program Maintenance Manual. This Program Maintenance Manual provides the information necessary to maintain and update the ICSD system. Two major types of program maintenance documentation are presented in this manual. The first is the source code for the dBase III+ routines and related non-dBase programs used in operating the ICSD. The second is listings of the major component database field structures. A third important consideration for dBase programming, the structure of index files, is presented in the listing …
Date:
June 1, 1991
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Application of optical fluctuation diagnostics to transport studies in high temperature tokamak plasmas
First data was obtained from the TFTR BES system in May 1990, after the prototype 4-channel system with photomultiplier detectors from PBX-M was transferred to the TFTR Hot Cell. The system was expanded to 16 spatial channels during the Summer 1990 run period, and data of interest was obtained near the end of the run in October 1990. The most attention has been given to a radial profile data set obtained for an L-mode plasma condition in TFTR, where we characterized the nature of the long-wavelength turbulence seen by the BES diagnostic. We summarize here highlights of the initial run with BES or TFTR. We also give a progress report on support activities at UW.
Date:
January 1, 1991
Creator:
Fonck, R.J.
Object Type:
Report
System:
The UNT Digital Library
Investigation of joining techniques for advanced austenitic alloys
Modified Alloys 316 and 800H, designed for high temperature service, have been developed at Oak Ridge National Laboratory. Assessment of the weldability of the advanced austenitic alloys has been conducted at the University of Tennessee. Four aspects of weldability of the advanced austenitic alloys were included in the investigation.
Date:
May 1, 1991
Creator:
Lundin, C. D.; Qiao, C. Y. P.; Kikuchi, Y.; Shi, C. & Gill, T. P. S.
Object Type:
Report
System:
The UNT Digital Library
The bioenergetics of salt tolerance
The aim of this project was to try to understand the adaptive mechanisms that organisms develop in order to respond to a sudden transformation in their environment to a salt shock.'' To study this problem we used a fresh water oxygenic photosynthetic cyanobacterium known as Synecoccus 6311. This organism suffers injury after this sudden exposure to high concentrations of sodium chloride equivalent to or even higher than that in sea water. Yet they are able to re-establish their photosynthetic activity which is partially injured and return to virtually normal growth rates. Identification of the temporal sequence of changes involved in adaptation to this stress was the rationale. Indeed this project employed a wide variety of biochemical and biophysical methods, including electron spin resonance techniques and nuclear magnetic resonance to study the bioenergetics and transport mechanisms, growth and energy changes in these organisms and how the structural components of the cells changed in response to adaptation to growth at high salinity. The problem has relevance for higher plants because most of the arable farmland in the work is already under use and that which is not used is usually in salite environments. Hence, understanding basic mechanisms of salt tolerance is a …
Date:
January 1, 1991
Creator:
Packer, L.
Object Type:
Report
System:
The UNT Digital Library
MetaBrowser: A combined browsing, query, and analysis tool
The MetaBrowser design is based on the premise that scientists should not be forced to learn new languages or commands for finding the data they are interested in and for selecting subsets of the data for further analysis. Furthermore, there should be a single system that permits browsing, query, and analysis of the data, so that the scientist does not have to switch between systems. The current version for the MetaBrowser was designed for the DOE CEDR (Comprehensive Epidemiological Data Resource) project, but the same principles can apply to other scientific disciplines. Browsing and query should be combined. It is quite natural for a user to explore the information in the database before deciding what subset of the data to select for further analysis. In general, if there is a large number of datasets (i.e. databases) in the system, then the user would want to find out information about the various datasets (called metadata), before choosing one or more datasets for further exploration. Thus, a metadatabase that holds information about datasets in the systems must exist.
Date:
April 1, 1991
Creator:
Shoshani, A. & Szeto, E.
Object Type:
Report
System:
The UNT Digital Library
Radiation induced micrencephaly in guinea pigs
A brain weight deficit of about 70 mg was induced at doses of approximately 75-mGy and a deficit of 60 mg was induced at 100 mGy. This confirms the effects projected and observed by Wanner and Edwards. Although the data do not demonstrate a clear dose-response relationship between the 75-mGy and 100-mGy groups, the data are statistically consistent with a dose-response effect because of the overlapping confidence intervals. The lack of a statistically significant observation is most likely related to the small difference in doses and the limited numbers of animals examined. There are several factors that can influence the brain weight of guinea pig pups, such as caging and housing conditions, the sex of the animal, and litter size. These should be taken into account for accurate analysis. Dam weight did not appear to have a significant effect. The confirmation of a micrencephalic effect induced x rays at doses of 75-mGy during this late embryonic stage of development is consistent with the findings of small head size induced in those exposed prior to the eight week of conception at Hiroshima. This implies a mechanism for micrencephaly different from those previously suggested and lends credence to a causal relation between …
Date:
January 1, 1991
Creator:
Wagner, L.K.; Johnston, D.A. & Felleman, D.J.
Object Type:
Report
System:
The UNT Digital Library
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
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
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