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Achieve!, October 31, 1990 (open access)

Achieve!, October 31, 1990

Periodic newsletter discussing information related to student drop-out rates, relevant legislative issues, and prevention programs. This issue focuses on child care problems and how they can affect the workforce.
Date: October 31, 1990
Creator: Texas Research League
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
An analysis of the finite-differenced, even-parity discrete-ordinates equations in slab geometry (open access)

An analysis of the finite-differenced, even-parity discrete-ordinates equations in slab geometry

Considerable effort has been expended in recent years in finding improved spatial differencing schemes for the neutron and radiation transport equations. Standard criteria used to select a candidate scheme are its order of spatial convergence for small mesh size and its positivity in the sense that positive solutions emerge from positive input data. More recently, it has become clear that truly robust schemes must behave well in diffusing regions and must be compatible with an effective iteration acceleration method. Recently, Morel and Larsen reported their work on a promising new method called the multiple balance method that has virtually all the desirable characteristics. Here we study a different approach to the problem by considering discrete-ordinates approximations to the even-parity transport equations. We analyze three spatial difference approaches: diamond differencing, cell-edge differencing, and cell-center differencing. For the case of isotropic scattering and sources, the latter two approaches are shown to be strictly positive, to be second-order accurate, to be compatible with derived diffusion synthetic acceleration methods, and to possess the necessary diffusion limits. Unlike previous work with the even-parity equation, we do not use finite elements or variational principles. 5 refs., 1 tab.
Date: January 31, 1990
Creator: Miller, W. F. Jr.
Object Type: Article
System: The UNT Digital Library
A research agenda for academic petroleum engineering programs (open access)

A research agenda for academic petroleum engineering programs

The development of a research agenda should be a direct way of portraying the scope of petroleum engineering, of identifying the critical technological issues faced by the profession,of elucidating the gaps between the existing research resources and the needs. and of outlining a program of research through which the petroleum engineering departments can be collectively of maximum service. Such an agenda would be of value to the profession of petroleum engineering, to industry and to government agencies, as well as to the faculty and students of the petroleum engineering departments. The purposes of the activity that led to this report, therefore, were to develop a statement to serve as a beginning research agenda for the petroleum engineering academic community; to bring together representatives of the petroleum engineering academic community to recognize the importance of developing a consensus posture with respect to research; and to provide a document that will assist in portraying to industry, government agencies and others the problems and needs of the petroleum engineering departments for conducting research. Contents of this report include; introduction; the background; the scope of petroleum engineering research; priority research topics and technological issues; non-technological research issues; and conclusions and recommendations.
Date: March 31, 1990
Creator: Calhoun, J. C. Jr.
Object Type: Report
System: The UNT Digital Library
Radiative Properties of Ash and Slag. Tenth Quarterly Report, January 1, 1990--March 30, 1990 (open access)

Radiative Properties of Ash and Slag. Tenth Quarterly Report, January 1, 1990--March 30, 1990

Thermal radiation plays a key role in the operation and efficiency of combustion systems, accounting for over 90% of the heat transfer. The analysis of radiative heat transfer in coal-fired boilers, combustion chambers and other energy systems requires accounting for the effects of inorganic deposits on bounding surfaces and of entrained particulates, such as pulverized coal, char, and fly-ash. These effects can be predicted; however, the accuracy in predicting the radiative properties of entrained pyrolysis (ash) and deposit layers (slag) is limited by inaccurate knowledge of the physical/chemical properties of the materials over a range of material temperatures and radiative wavelengths that is representative of conditions in practical combustion systems. The objective of this project is to make laboratory measurements of the radiative properties of extracted ash and slag deposit samples and compare to model predictions.
Date: December 31, 1990
Creator: Solomon, P. R. & Markham, J. R.
Object Type: Report
System: The UNT Digital Library
An assessment of PCB degradation by microogransims including methods for measuring mineralization (open access)

An assessment of PCB degradation by microogransims including methods for measuring mineralization

These studies sought to isolate and identify organism(s) from PCB contaminated soil and sediment that degrade PCB; to provide information on the potential of organisms in soil samples taken from a PCB-contaminated area to mineralize or dechlorinate PCB congeners; to assess potential enhancement of PCB biodegradation as a result of nutritional amendment of the samples; and to carry out analyses of successive lysimeter samples to determine whether field treatments have had an effect on the capacity of soil microbes to mineralize PCBS. We have expended considerable effort to validate the fractionation procedure used to assess mineralization and conversion of PCB substrates. The assessment relies on the ability to measure [{sup 14}C]-labeled CO{sub 2} in the presence of potentially volatile [{sup 14}C]-labeled PCB and degradation products to differentiate between volatile and non-volatile [{sup 14}C]-labeled compounds between water-soluble products of metabolism and a mixture of unchanged substrate and other water-insoluble products and between metabolism and loss or non-extractability of the substrate.
Date: December 31, 1990
Creator: Hadden, C.; Edenborn, H.; Osborne, T.; Holdsworth, G. & Revis, N.
Object Type: Report
System: The UNT Digital Library
The effect of temperature upon the fatigue crack propagation behavior of Alloy 625 (open access)

The effect of temperature upon the fatigue crack propagation behavior of Alloy 625

Fatigue crack propagation of annealed Alloy 625 was studied in air at 24--649 C. Crack growth rates tend to increase with temperature. Two heats were studied; differences in behavior between them suggest a heat-to-heat variability. Characterization of stress ratio (R=K{sub min}/K{sub max}) effects was also done at 538 C.
Date: December 31, 1990
Creator: James, L. A.
Object Type: Article
System: The UNT Digital Library
A secure file manager for UNIX (open access)

A secure file manager for UNIX

The development of a secure file management system for a UNIX-based computer facility with supercomputers and workstations is described. Specifically, UNIX in its usual form does not address: (1) Operation which would satisfy rigorous security requirements. (2) Online space management in an environment where total data demands would be many times the actual online capacity. (3) Making the file management system part of a computer network in which users of any computer in the local network could retrieve data generated on any other computer in the network. The characteristics of UNIX can be exploited to develop a portable, secure file manager which would operate on computer systems ranging from workstations to supercomputers. Implementation considerations making unusual use of UNIX features, rather than requiring extensive internal system changes, are described, and implementation using the Cray Research Inc. UNICOS operating system is outlined.
Date: December 31, 1990
Creator: DeVries, R. G.
Object Type: Article
System: The UNT Digital Library
An analysis of heating and cooling conservation features in commercial buildings (open access)

An analysis of heating and cooling conservation features in commercial buildings

One purpose of this study is to estimate the relationship in commercial buildings between conservation investments, fuel prices, building occupancy and building characteristics for new buildings and for existing buildings. The database is a nationwide survey of energy in commercial buildings conducted by the Energy Information Administration (EIA) in 1906. Some simple cross-tabulations indicate that conservation measures vary with building size, building age, and fuel used for building heating. Regression estimates of a conservation model indicate that the number of conservation model indicate that the number of conservation features installed during construction is a positive function of the price of the heating fuel at the time of construction. Subsequent additions of conservation features are positively correlated with increases in heating fuel prices. Given the EIA projection of relatively stable future energy prices, the number of retrofits may not increase significantly. Also, energy efficiency in new buildings may not continue to increase relative to current new buildings. If fuel prices affect consumption via initial conservation investments, current fuel prices, marginal or average, are not the appropriate specification. The fuel price regression results indicate that conservation investments in new buildings are responsive to market signals. Retrofits are less responsive to market signals. …
Date: December 31, 1990
Creator: Sutherland, R. J.
Object Type: Article
System: The UNT Digital Library
Progress report for the scintillator plate calorimeter subsystem (open access)

Progress report for the scintillator plate calorimeter subsystem

This report covers the work completed in FY90 by ANL staff and those of Westinghouse STC and BICRON Corporation under subcontract to ANL towards the design of a compensating calorimeter based on the use of scintillator plate as the sensitive medium. It is presented as five task sections dealing with respectively mechanical design; simulation studies; optical system design; electronics development; development of rad hard plastic scintillator and wavelength shifter and a summary. The work carried out by the University of Tennessee under a subcontract from ANL is reported separately. Finally, as principal institution with responsibility for the overall management of this subsystem effort, the summary here reports the conclusions resulting from the work of the collaboration and their impact on our proposed direction of effort in FY91. This proposal, for obvious reasons is given separately.
Date: December 31, 1990
Creator: unknown
Object Type: Report
System: The UNT Digital Library
[Model catalyst studies of active sites and metal-support interactions on vanadia and vanadia-supported catalysts] (open access)

[Model catalyst studies of active sites and metal-support interactions on vanadia and vanadia-supported catalysts]

The report is divided into the following: HREELS studies of adsorption on Rh/TiO{sub 2} model catalysts; photoemission studies of the Rh/TiO{sub 2} interaction; V-O-Ti interactions in supported vanadia catalysts; and surface physics and chemistry of vanadium oxides.
Date: December 31, 1990
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Experimental and theoretical investigation of the production of HCl and some metal chlorides in magmatic/hydrothermal systems. Progress report (open access)

Experimental and theoretical investigation of the production of HCl and some metal chlorides in magmatic/hydrothermal systems. Progress report

Hydrothermal experiments on the partitioning of HCl and copper chloride in the system silicate melt-hydrosaline liquid-aqueous vapor are described. Modelling of the aqueous phase evolution process is discussed. (MHR)
Date: December 31, 1990
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Unique applications of personal computers in the welding environment (open access)

Unique applications of personal computers in the welding environment

The personal computer was found to be useful in supporting a variety of welding applications: 3-D representation of crack propagation using CADD software, storage and retrieval of photographic data using an image capture board, automated positioning of the welding electrode for GTA welding, interactive computer based voice communication for welding operations, surface temperature measurements of welded structures, and inventory control of weld material through use of bar codes.
Date: December 31, 1990
Creator: Glickstein, S. S.
Object Type: Article
System: The UNT Digital Library
A Los Alamos concept for accelerator transmutation of waste and energy production (ATW) (open access)

A Los Alamos concept for accelerator transmutation of waste and energy production (ATW)

This document contains the diagrams presented at the ATW (Accelerator Transmutation of Waste and Energy Production) External Review, December 10-12, 1990, held at Los Alamos National Laboratory. Included are the charge to the committee and the presentations for the committee`s review. Topics of the presentations included an overview of the concept, LINAC technology, near-term application -- high-level defense wastes (intense thermal neutron source, chemistry and materials), advanced application of the ATW concept -- fission energy without a high-level waste stream (overview, advanced technology, and advanced chemistry), and a summary of the research issues.
Date: December 31, 1990
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Siphon breaker design requirements. Progress report (open access)

Siphon breaker design requirements. Progress report

This project was intended to provide experimental data on siphon flow effects. The system was to be modeled with the RELAP code and the predicted and measured performances compared. The experimental system consists of a 500-gallon upper tank, a 4-inch downcomer pipe, a lower catch tank, a return pump and associated piping. The downcomer pipe is made of 4-inch clear acrylic pipe so the flow patterns could be observed and video taped during the test runs.
Date: December 31, 1990
Creator: Neill, D. T. & Stephens, A. G.
Object Type: Report
System: The UNT Digital Library
Far infrared fusion plasma diagnostics. Task 3A, Progress report, FY 1990 (open access)

Far infrared fusion plasma diagnostics. Task 3A, Progress report, FY 1990

Over the last several years, reflectometry has grown in importance as a diagnostic for both steady-state density Profiles as well as for the investigation of density fluctuations and turbulence. As a diagnostic for density profile measurement, it is generally believed to be well understood in the tokamak environment. However, its use as a fluctuation diagnostic is hampered by a lack of quantitative experimental understanding of its wavenumber sensitivity and spatial resolution. Several researchers, have theoretically investigated these questions. However, prior to the UCLA laboratory investigation, no group has experimentally investigated these questions. Because of the reflectometer`s importance to the world effort in understanding plasma turbulence and transport, UCLA has, over the last year, made its primary Task IIIA effort the resolution of these questions. UCLA has taken the lead in a quantitative experimental understanding of reflectometer data as applied to the measurement of density fluctuations. In addition to this, work has proceeded on the design, construction, and installation of a reflectometer system on UCLA`s CCT tokamak. This effort will allow a comparison between the improved confinement regimes (H-mode) observed on both the DIII-D and CCT machines with the goal of achieving a physics understanding of the phenomena. Preliminary investigation of …
Date: December 31, 1990
Creator: Luhmann, N. C. Jr. & Peebles, W. A.
Object Type: Report
System: The UNT Digital Library
Activity composition relationships in silicate melts. Final report (open access)

Activity composition relationships in silicate melts. Final report

Equipment progress include furnace construction and electron microprobe installation. The following studies are underway: phase equilibria along basalt-rhyolite mixing line (olivine crystallization from natural silicic andensites, distribution of Fe and Mg between olivine and liquid, dist. of Ca and Na between plagioclase and liquid), enthalpy-composition relations in magmas (bulk heat capacity of alkali basalt), density model for magma ascent and contamination, thermobarometry in igneous systems (olivine/plagioclase phenocryst growth in Quat. basalt), high-pressure phase equilibria of alkali basalt, basalt-quartz mixing experiments, phase equilibria of East African basalts, and granitic minerals in mafic magma. (DLC)
Date: December 31, 1990
Creator: Glazner, A. F.
Object Type: Report
System: The UNT Digital Library
High-frequency acoustic sensors for operation in a gaseous medium. Final report (open access)

High-frequency acoustic sensors for operation in a gaseous medium. Final report

Photothermal microscopy is a technique for measuring thermal properties on a small scale by using focused laser beams as heat sources and as temperature probes. Typically used for nondestructive evaluation (NDE) of materials, its main advantage is its ability to measure types of flaws that are not visible optically or acoustically. Because of the optical nature of photothermal microscopy, sub-micron resolutions can be obtained in many of these thermal measurements. The greatest limitation of these systems is their relatively poor signal-to-noise ratios and, consequently, slow imaging speeds. To circumvent this problem, a variety of approaches to the detection of thermal waves has been pursued in recent years. This thesis compares the relative merits of a common class of techniques that rely on direct observation of physical changes in the heated sample, including a novel approach to interferometric measurement of the thermal expansion. It is found that the optimum approach depends not only on the physical properties of the sample being studies, but also upon the resolution of the experiment and the damage threshold of the specimen. Finally, this dissertation describes the applications of photothermal microscopy to the study of the anisotropic thermal properties of the new high-{Tc} superconductors. By adding …
Date: December 31, 1990
Creator: Kino, G. S.
Object Type: Report
System: The UNT Digital Library
Monte Carlo simulation of gamma ray scanning gauge (open access)

Monte Carlo simulation of gamma ray scanning gauge

A gamma ray scanning gauge was simulated with Monte Carlo to study the properties of gamma scanning gauges and to resolve the counts coming from a {sup 235}U source from those coming from a contaminant ({sup 232}U) whose daughters emit high energy gamma rays. The simulation has been used to infer the amount of the {sup 232}U contaminant in a {sup 235}U source to select the best size for the NaI(Tl) detector crystal to minimize the effect of the contaminant. The results demonstrate that Monte Carlo simulation provides a systematic tool for designing a gauge with desired properties and for estimating properties of the gamma source from measured count rates.
Date: December 31, 1990
Creator: Hartfield, G. L.; Freeman, L. B.; Dei, D. E.; Emert, C. J.; Glickstein, S. S.; Kahler, A. C. et al.
Object Type: Article
System: The UNT Digital Library
The photoexcited triplet state of sapphyrin dication: Unusual spin alignment in monomers and spin delocalization in dimers (open access)

The photoexcited triplet state of sapphyrin dication: Unusual spin alignment in monomers and spin delocalization in dimers

Sapphyrin (Sap) and its stable dicationic form, Sap{sup 2+}, originally prepared by Woodawrd and Johnson, are large porphyrin-like systems which exhibit unique photophysical and photochemical properties. We report on the triplet diode detection, by time-resolved CW EPR, of (Sap{sup 2+}){sup T} randomly oriented in toluene (as monomers), ethanol (as dimers), and partially oriented in a nematic liquid crystal (as monomers). The substantial reduction of both zero-field splitting (ZFS) parameters (D and E) in the dimer, is interpreted in terms of spin delocalization (charge transfer) among the monomers within the dimer, (Sap{sup 2+}){sub 2}. The EPR line shape of Sap{sup 2+} in the liquid crystal suggests that, unlike other known porphyrinoid systems, the ZFS term D is associated with the in-plane alignment of the triplet spins along the C{sub 2v} symmetry axis, Z.
Date: January 31, 1990
Creator: Levanon, H.; Michaeli, S.; Regev, A.; Galili, T.; Cyr, M. & Sessler, J. L.
Object Type: Report
System: The UNT Digital Library
Effect of oxide particle distribution on the helium-induced fracture of copper (open access)

Effect of oxide particle distribution on the helium-induced fracture of copper

Long-term exposure to tritium (H{sup 3}) gas can degrade the mechanical properties of copper alloys while similar exposure to protium (H{sup 1}) gas does not cause such degradation. This difference in behavior is attributed to the presence of helium which is generated by the radioactive decay of tritium. The accumulation of helium, which is virtually insoluble in the copper lattice, can cause the nucleation of cavities along grain boundaries and promote intergranular fracture. Permeation studies have shown that oxide particles act as trap sites for diffusing hydrogen isotopes, and thus may affect the susceptibility of copper to helium-induced degradation by altering the initial tritium distribution in the metal lattice. Tensile and metallographic data demonstrate that oxide particles trap both tritium and helium and decrease the susceptibility of copper to helium-induced intergranular fracture. 25 refs, 3 tabs, 12 figs.
Date: December 31, 1990
Creator: Wheeler, D. A.
Object Type: Article
System: The UNT Digital Library
Transverse liquid fuel jet breakup, burning, and ignition (open access)

Transverse liquid fuel jet breakup, burning, and ignition

An analytical/numerical study of the breakup, burning, and ignition of liquid fuels injected transversely into a hot air stream is conducted. The non-reacting liquid jet breakup location is determined by the local sonic point criterion first proposed by Schetz, et al. (1980). Two models, one employing analysis of an elliptical jet cross-section and the other employing a two-dimensional blunt body to represent the transverse jet, have been used for sonic point calculations. An auxiliary criterion based on surface tension stability is used as a separate means of determining the breakup location. For the reacting liquid jet problem, a diffusion flame supported by a one-step chemical reaction within the gaseous boundary layer is solved along the ellipse surface in subsonic crossflow. Typical flame structures and concentration profiles have been calculated for various locations along the jet cross-section as a function of upstream Mach numbers. The integrated reaction rate along the jet cross-section is used to predict ignition position, which is found to be situated near the stagnation point. While a multi-step reaction is needed to represent the ignition process more accurately, the present calculation does yield reasonable predictions concerning ignition along a curved surface.
Date: December 31, 1990
Creator: Li, H.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Injection nozzle materials for a coal-fueled diesel locomotive (open access)

Injection nozzle materials for a coal-fueled diesel locomotive

In order to identify materials resistant to coal water mixture (CWM) erosive wear, a number of materials were evaluated using both orifice slurry and dry air erosion tests. Both erosion tests ranked materials in the same order, and the most erosion resistant material identified was sintered diamond compact. Based on operation using CWM in a single-cylinder locomotive test, superhard nozzle materials such as diamond, cubic boron nitride, and perhaps TiB{sub 2} were found to be necessary in order to obtain a reasonable operating life. An injection nozzle using sintered diamond compacts was designed and built, and has operated successfully in a CWM fired locomotive engine.
Date: December 31, 1990
Creator: Mehan, R. L.; Leonard, G. L.; Johnson, R. N. & Lavigne, R. G.
Object Type: Article
System: The UNT Digital Library
Workshop on major SSC detectors (open access)

Workshop on major SSC detectors

This report contains notes generated during the workshop.
Date: December 31, 1990
Creator: unknown
Object Type: Article
System: The UNT Digital Library
Thermal hydraulics of steam generator sludge (open access)

Thermal hydraulics of steam generator sludge

Experimental and analytical studies of thermal hydraulic processes in commercial steam generator tube sheet sludge have been previously reported. That work was performed because the authors believed that tubing corrosion occurs when the sludge deposit becomes too deep for the liquid to penetrate freely, leading to formation of a liquid deficient region with high chemical concentrations on the tube surface. The primary objective of this work is to determine analytically the extent of liquid penetration into porous sludge. The secondary objectives are determinations of liquid saturation and chemical concentration profiles along the sludge covered tube length. The method described in this paper differs from those used in previous works in that it allows specification of porosity and permeability as a function of distance into the sludge and, also, in some of the auxiliary equations used.
Date: December 31, 1990
Creator: Ulke, A. & Goldberg, I.
Object Type: Report
System: The UNT Digital Library