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Correlation of stability/rheology relationship with coal properties and chemical additives. Quarterly progress report, December 15, 1989--March 15, 1990
The overall objective of this project is to perform experiments to evaluate the necessary boundary conditions in the preparation and utilization of Coal Water Slurries and also develop a data base for the conceptual analysis of a prescription to predict slurry quality for a given coal candidate.
Date:
December 31, 1990
Creator:
Ohene, F.
Object Type:
Report
System:
The UNT Digital Library
Counterrotating brushless dc permanent magnet motor
An brushless DC permanent magnet motor is provided for driving an autonomous underwater vehicle. In one embodiment, the motor comprises four substantially flat stators disposed in stacked relationship, with pairs of the stators being axially spaced and each of the stators comprising a tape-wound stator coil; and a first and second substantially flat rotors disposed between the spaced pairs of stators. Each of the rotors includes an annular array of permanent magnets embedded therein. A first shaft is connected to the first rotor and a second, concentric shaft is connected to the second rotor, and drive unit causes rotation of the two shafts in opposite directions. The second shaft comprises a hollow tube having a central bore therein in which the first shaft is disposed. Two different sets of bearings support the first and second shAfts. In another embodiment, the motor comprises two ironless stators and pairs and rotors mounted no opposite sides of the stators and driven by counterrotating shafts.
Date:
December 31, 1990
Creator:
Hawsey, R. A. & Bailey, J. M.
Object Type:
Patent
System:
The UNT Digital Library
Data-driven parallel production systems: A macro actor/token implementation
The importance of production systems in artificial intelligence has been repeatedly demonstrated by a number of expert systems. Much effort has therefore been expended on finding an efficient processing mechanism to process production systems. While data-flow principles of execution offer the promise of high programmability for numerical computations, the authors study here variable resolution actors, called macro actors, a processing mechanism for production systems. Characteristics existing in the production system paradigm are identified, based on which they introduce macro tokens as a companion to macro actors. A set of guideline is identified in the context of production systems to derive well-formed macro actors from primitive micro actors. Parallel pattern matching is written in macro actors/tokens to be executed on Macro Data-flow simulator. Simulation results demonstrate that the macro approach can be an efficient implementation of the production system paradigm.
Date:
December 31, 1990
Creator:
Sohn, A. & Gaudiot, J.-L.
Object Type:
Article
System:
The UNT Digital Library
Decomposition of sodium tetraphenylborate
The chemical decomposition of aqueous alkaline solutions of sodium tetraphenylborate, NaTPB, has been investigated. The focus of the investigation is on the determination of components which influence NaTPB decomposition. Copper(II) ions, solution temperature, and solution pH (hydroxide ion concentration) have all been demonstrated to affect NaTPB stability. Their relationship with each other and the stability of NaTPB has been determined. Based upon this knowledge, a method for stabilizing NaTPB was determined. Decomposition of a NaTPB solution was delayed with the addition of sodium hydroxide. In additional work, the elimination of oxygen from the reaction environment did not prevent NaTPB decomposition in the presence of copper(II) ions but did, however, affect the course of decomposition.
Date:
December 31, 1990
Creator:
Barnes, M. J.
Object Type:
Article
System:
The UNT Digital Library
A decoupled data-driven architecture with vectors and macro actors
This paper presents the implementation of scientific programs on a decoupled data-driven architecture with vectors and macro actors. This hybrid multiprocessor combines the dynamic data-flow principles of execution with the control-flow of the von Neumann model of execution. The two major ideas utilized by the decoupled model are: Vector and macro actors with variable resolution, and asynchronous execution of graph and computation operations. The compiler generates graphs with various-sized actors in order to match the characteristics of the computation. For instance, vector actors are proposed for many aspects of scientific computing while lower resolution (complier-generated collection of scalar actors) or higher resolution (scalar actors) is used for unvectorizable programs. A block-scheduling technique for extracting more parallelism from sequential constructs is incorporated in the decoupled architecture. In addition a graph-level priority-scheduling mechanism is implemented that improves resource utilization and yields higher performance. A graph unit executes all graph operations and a computation unit executes all computation operations. The independence of the two main units of the machine allows the efficient pipelined execution of macro actors with diverse granularity characteristics.
Date:
December 31, 1990
Creator:
Evripidou, P. & Gaudiot, J. L.
Object Type:
Article
System:
The UNT Digital Library
A decoupled graph/computation data-driven architecture with variable-resolution actors
This paper presents a hybrid multiprocessor architecture that combines the advantages of the dynamic data-flow principles of execution with those of the control-flow model of execution. Two major design ideas are utilized by the proposed model: asynchronous execution of graph and computation operations, and variable- resolution actors. The independence of the two main unites of the machine allows an efficient implementation of functional/data-flow principles with conventional, mature technology. The compiler generates graphs with variable-sized actors in order to match the characteristics of the application to the target machine. For instance, vector actors are proposed for many aspects of scientific computing, while lower resolution (Compound Macro Actors) or conversely higher resolution (atomic instruction actors) is used for unvectorizable programs.
Date:
December 31, 1990
Creator:
Evripidou, P. & Gaudiot, J. L.
Object Type:
Article
System:
The UNT Digital Library
Design and calibration of a CO{sub 2}-laser nephelometer to measure the radiative properties of coal particles
In is paper, we will discuss the design and calibration of a CO{sub 2}-laser nephelometer for angular light scattering measurements to determine the effective radiative properties of pulverized-coal particles in a non-flame, planar system in-situ. A nephelometer is an instrument used for angular detection of scattered light incident on a cloud of particles. Its essential elements include a collimated light source and an arm which houses light collection optics and detectors. The arm can be rotated to record the angular scattered intensity distribution. A major problem when conducting experiments of this nature is that the intensity of the scattered light by pulverized-coal particles at angles other than the forward scattering direction can be as much as two to three orders of magnitude lower than the intensity at angles close to {theta} = O{sup o}. This effect is more pronounced for larger size parameters. In order to have sufficiently strong signals at a wide range of angles, a 50 watt CO{sub 2}-laser operating at 10.6 {mu}m is used in the experiments.
Date:
December 31, 1990
Creator:
Bush, M. B.; D`sa, D. A.; Manickavasagam, S. & Menguec, M. P.
Object Type:
Article
System:
The UNT Digital Library
Design of a full scale model fuel assembly for full power production reactor flow excursion experiments
A novel full scale production reactor fuel assembly model was designed and built to study thermal-hydraulic effects of postulated Savannah River Site (SRS) nuclear reactor accidents. The electrically heated model was constructed to simulate the unique annular concentric tube geometry of fuel assemblies in SRS nuclear production reactors. Several major design challenges were overcome in order to produce the prototypic geometry and thermal-hydraulic conditions. The two concentric heater tubes (total power over 6 MW and maximum heat flux of 3.5 MW/m{sup 2}) (1.1E+6 BTU/(ft{sup 2}hr)) were designed to closely simulate the thermal characteristics of SRS uranium-aluminum nuclear fuel. The paper discusses the design of the model fuel assembly, which met requirements of maintaining prototypic geometric and hydraulic characteristics, and approximate thermal similarity. The model had a cosine axial power profile and the electrical resistance was compatible with the existing power supply. The model fuel assembly was equipped with a set of instruments useful for code analysis, and durable enough to survive a number of LOCA transients. These instruments were sufficiently responsive to record the response of the fuel assembly to the imposed transient.
Date:
December 31, 1990
Creator:
Nash, C. A.; Blake, J. E. & Rush, G. C.
Object Type:
Article
System:
The UNT Digital Library
Design of kicker/bumper magnet and PFN for
Three fast Pulsed kicker/bumper magnets are required in the positron accumulator ring (PAR) for the purpose of beam injection and/or extraction at 450 MeV. According to the Conceptual Design Report (CDR), these three magnets have, identical specifications and are expected to produce identical magnetic fields. Therefore, they will have the same design. Each kicker/bumper magnet is required to generate a magnetic field of 0.06 T with a rise time of 65 ns, a flat top of 80 ns and a fall time of 90 ns, respectively. A fast pulsed magnet system normally consists of a high voltage dc power supply, charging/discharging switches which are tetrodes and thyratrons in most cases, a pulse forming network (PFN), a magnet assembly consisting of a ferrite magnet, a matching capacitor or capacitors and a load (termination) resistor. The primary objective of this study is the design of the pulse forming network and magnet assembly.
Date:
December 31, 1990
Creator:
Wang, Ju & Volk, G. J.
Object Type:
Report
System:
The UNT Digital Library
Destruction of acid gas emissions
A method of destroying NO{sub x} and SO{sub x} in a combustion gas is disclosed. The method includes generating active species by treating stable molecules in a high temperature plasma. Ammonia, methane, steam, hydrogen, nitrogen or a combustion of these gases can be selected as the stable molecules. The gases are subjected to plasma conditions sufficient to create free radicals, ions or excited atoms such as N, NH, NH{sub 2}, OH, CH and/or CH{sub 2}. These active species are injected into a combustion gas at a location of sufficiently high temperature to maintain the species in active state and permit them to react with NO{sub x} and SO{sub x}. Typically the injection is made into the immediate post-combustion gases at temperatures of 475--950{degrees}C. 1 fig.
Date:
December 31, 1990
Creator:
Mathur, M. P.; Fu, Yuan C.; Ekmann, J. M. & Boyle, J. M.
Object Type:
Patent
System:
The UNT Digital Library
Detection device for hazardous material
This invention is comprised of a detection device that is activated by the interaction of a hazardous chemical with a coating interactive with said chemical on an optical fiber thereby reducing the amount of light passing through the fiber to a light detector. A combination of optical filters separates the light into a signal beam and a reference beam which after detection, appropriate amplification, and comparison with preset internal signals, activates an alarm means if a predetermined level of contaminant is observed.
Date:
December 31, 1990
Creator:
Partin, J. K. & Grey, A. E.
Object Type:
Patent
System:
The UNT Digital Library
Determination of local radiative properties in coal-fired flames. Technical progress report, September 16, 1989--March 15, 1990
Our primary goal in this research is to determine the effective radiative properties of pulverized coal particles in situ. These effective properties can be obtained from a detailed, interactive experimental/analytical procedure. First, a series of experiments are performed, and the attenuation and scattering of incident radiation at several angular orientations are recorded. The physical and optical characteristics of the total particle cloud determines the amount of attenuation, and this information is included in the measured projection data. Effective properties can be determined by solving the inverse radiation problem in a corresponding geometry using these projection intensity data as input. Following this, empirical relations for ``effective radiative properties`` can be derived for given physical conditions. This can be achieved if other physical properties, such as volume fraction and particle size distribution, temperature of the particles and combustion gases, and concentration distribution of gam can be predicted from theory or measured in parallel experiments, and their contributions to the experimental data are quantified. During the period covered by this report, we concentrated our efforts to measure the effective radiative properties of cold coal particles. For this purpose, we used a test cell to obtain a one-dimensional slab of coal particles. The inverse …
Date:
December 31, 1990
Creator:
Menguec, M. P.
Object Type:
Report
System:
The UNT Digital Library
Determination of noble metals in Savannah River Site high-level radioactive sludge
High-level radioactive sludge at the Savannah River Site (SRS) will be processed at the Defense Waste Processing Facility (DWPF) into durable borosilicate glass wasteforms. The sludges are analyzed for elemental content before processing to ensure compatibility with the glass-making processes. Noble metal fission products in sludge, can under certain conditions, cause problems in the glass melter. Therefore, reliable noble metal determinations are important. The scheme used to measure noble metals in SRS sludges consists of dissolving sludge with hot aqua regia followed by determinations with inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and ICP-Mass Spectroscopy (ICP-MS) techniques. ICP-MS is the preferred method for measuring trace levels of noble metals in SRS radioactive waste because of superior sensitivity. Analytical results are presented for the two major types of SRS sludge.
Date:
December 31, 1990
Creator:
Coleman, C. J.; Kinard, W. F.; Bibler, N. E.; Bickford, D. F. & Ramsey, W. G.
Object Type:
Article
System:
The UNT Digital Library
[Developing a physical map of human chromosome 22 using Pace electrophoresis and large fragment cloning]. Annual report, October 1, 1989--September 30, 1990
In the past year the authors have made significant progress in the development of a bacterial based cloning system for large fragments of mammalian DNA. They have completed construction of several recombination deficient bacterial host strains designed to minimize homologous recombination arising with repeats within cloned DNA. Despite the multiple mutations, these strains are viable and grow readily on standard media (LB). One of the chief attractions of a bacterial system is the promise of high transformation efficiencies. The author have pursued two separate strategies with the vector. The first makes use of the cos sites in the vector to package cloned DNA as phage particles for infection. By maintaining the vector as a single copy in the recombination minus host, they believe that the recombination that affects conventional cosmid libraries will be eliminated. They encountered no difficulties in preparing such a ``Fosmid`` (F factor based cosmid) library of human DNA.
Date:
December 31, 1990
Creator:
Simon, M.I.
Object Type:
Report
System:
The UNT Digital Library
Developing computer systems to support emergency operations: Standardization efforts by the Department of Energy and implementation at the DOE Savannah River Site
This paper describes the development of standards for emergency operations computer systems for the US Department of Energy (DOE). The proposed DOE computer standards prescribe the necessary power and simplicity to meet the expanding needs of emergency managers. Standards include networked UNIX workstations based on the client server model and software that presents information graphically using icons and windowing technology. DOE standards are based on those of the computer industry although Proposed DOE is implementing the latest technology to ensure a solid base for future growth. A case of how these proposed standards are being implemented is also presented. The Savannah River Site (SRS), a DOE facility near Aiken, South Carolina is automating a manual information system, proven over years of development. This system is generalized as a model that can apply to most, if not all, Emergency Operations Centers. This model can provide timely and validated information to emergency managers. By automating this proven system, the system is made easier to use. As experience in the case study demonstrates, computers are only an effective information tool when used as part of a proven process.
Date:
December 31, 1990
Creator:
DeBusk, R. E.; Fulton, G. J. & O`Dell, J. J.
Object Type:
Article
System:
The UNT Digital Library
Development and testing of commercial-scale, coal-fired combustion systems, Phase 3. Technical progress report, October 1990--December 1990
The US Department of Energy`s Pittsburgh Energy Technology Center (PETC) is actively pursuing the development and testing of coal-fired combustion systems for residential, commercial, and industrial market sectors. In response, MTCI initiated the development of a new combustor technology based on the principle of pulse combustion under the sponsorship of PETC (Contract No. AC22-83PC60419). The initial pulse combustor development program was conducted in three phases (MTCI, Development of a Pulsed Coal Combustor Fired with CWM, Phase III Final Report, DOE Contract No. AC22-83PC60419, November 1986). Phase I included a review of the prior art in the area of pulse combustion and the development of pulse combustor design concepts. It led to the conclusion that pulse combustors offer technical and base-of-operation advantages over conventional burners and also indicated favorable economics for replacement of oil- and gas-fired equipment.
Date:
December 31, 1990
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Development of dosimetric approaches to treatment planning for radioimmunotherapy. Annual report 1989--1990
The objective of quantitative imaging is to provide pharmacokinetic information for patients that is analogous to that provided by biodistribution studies in mice. Radionuclide images depict the distribution of labeled antibodies in-vivo; thus the amount of radionuclide in a specific organ or site can be estimated by relating the counts detected in a defined region of interest to the total radionuclide content. This pharmacokinetic information can be used to obtain definitive and relevant answers to basic questions of importance for optimizing radioimmunoimaging and radioimmunotherapy and, in addition, can provide a data base from which to calculate the distribution of radiation absorbed doses. The research employs quantitative imaging in evaluating therapies. Quantitative imaging is performed by a certified nuclear medicine technician using the Siemens gamma camera interfaced with the microVAX II. The technician processes the imaging data and obtains pharmacokinetic information from it using programs developed by the authors and others. A large amount of data has been acquired and analyzed on the pharmacokinetics, dosimetry and toxicity of radiolabeled monoclonal therapy. Important dosimetry data on the whole body, marrow and tumor doses are available and all studies are archived so that they can be retrospectively analyzed. Although the radiation absorbed doses …
Date:
December 31, 1990
Creator:
DeNardo, S. J.
Object Type:
Report
System:
The UNT Digital Library
The development of precipitated iron catalysts with improved stability. Technical progress report, April 1, 1990--June 30, 1990
Precipitated iron catalysts are expected to be used in the next generation of slurry reactors for the large-scale production of transportation fuels from synthesis gas. These reactors may operate at higher temperatures and lower H {sub 2}: CO ratios relative to the Sasol Arge reactor. The feasibility of iron catalysts has been demonstrated under relatively mild Arge-type conditions but not under the more severe slurry conditions. The goal of this program is to identify the chemical principles governing the deactivation of precipitated iron catalysts during Fischer-Tropsch synthesis and to use these chemical principles in the design of catalysts suitable for slurry reactors.
Date:
December 31, 1990
Creator:
Shah, P. P.
Object Type:
Report
System:
The UNT Digital Library
Direct conversion of light hydrocarbon gases to liquid fuel. Quarterly technical status report No. 11 for thrid quarter FY 1990
The objective of this program is to investigate the direct conversion of light gaseous hydrocarbons, such as those produced during Fischer-Tropsch synthesis or as a product of gasification, to liquid transportation fuels via a partial oxidation process. The process will be tested in an existing pilot plant to obtain credible mass balances. Specific objectives to be met include determination of optimal process conditions, investigation of various processing options (e.g. feed injection, product quench, and recycle systems), and evaluation of the various options will be performed as experimental data become available.
Date:
December 31, 1990
Creator:
Foral, M. J.
Object Type:
Report
System:
The UNT Digital Library
Direct conversion of light hydrocarbon gases to liquid fuel. Quarterly technical status report No. 15 fourth quarter FY 1990
The objective of this program is to investigate the direct conversion of light gaseous hydrocarbons, such as those produced during Fischer-Tropsch synthesis or as a product of gasification, to liquid transportation fuels via a partial oxidation process. The process will be tested in an existing pilot plant to obtain credible mass balances. Specific objectives to be met include determination of optimal process conditions, investigation of various processing options (e.g. feed injection, product quench, and recycle systems), and evaluation of an enhanced yield thermal/catalytic system. Economic evaluation of the various options will be performed as experimental data become available.
Date:
December 31, 1990
Creator:
Foral, M. J.
Object Type:
Report
System:
The UNT Digital Library
Drilling and geohydrologic data for test hole USW UZ-1, Yucca Mountain, Nye County, Nevada
This report presents data collected to determine the hydrologic characteristics of tuffaceous rocks penetrated in test hole USW UZ-1. The borehole is the first of two deep, large-diameter, unsaturated-zone test holes dry drilled using the vacuum/reverse-air-circulation method. This test hole was drilled in and near the southwestern part of the Nevada Test Site, Nye County, Nevada, in a program conducted in cooperation with the US Department of Energy. These investigations are part of the Yucca Mountain Project (formerly the Nevada Nuclear Waste Storage Investigations) to identify a potentially suitable site for the storage of high-level radioactive wastes. Data are presented for bit and casing configurations, coring methods, sample collection, drilling rate, borehole deviation, and out-of-gage borehole. Geologic data for this borehole include geophysical logs, a lithologic log of drill-bit cuttings, and strike and distribution of fractures. Hydrologic data include water-content and water-potential measurements of drill-bit cuttings, water-level measurements, and physical and chemical analyses of water. Laboratory measurements of moisture content and matric properties from the larger drill-bit cutting fragments were considered to be representative of in-situ conditions. 3 refs., 5 figs., 10 tabs.
Date:
December 31, 1990
Creator:
Whitfield, M.S.; Thordarson, W.; Hammermeister, D.P. & Warner, J.B.
Object Type:
Report
System:
The UNT Digital Library
Dynamic load balancing in a concurrent plasma PIC code on the JPL/Caltech Mark III hypercube
Dynamic load balancing has been implemented in a concurrent one-dimensional electromagnetic plasma particle-in-cell (PIC) simulation code using a method which adds very little overhead to the parallel code. In PIC codes, the orbits of many interacting plasma electrons and ions are followed as an initial value problem as the particles move in electromagnetic fields calculated self-consistently from the particle motions. The code was implemented using the GCPIC algorithm in which the particles are divided among processors by partitioning the spatial domain of the simulation. The problem is load-balanced by partitioning the spatial domain so that each partition has approximately the same number of particles. During the simulation, the partitions are dynamically recreated as the spatial distribution of the particles changes in order to maintain processor load balance.
Date:
December 31, 1990
Creator:
Liewer, P. C.; Leaver, E. W.; Decyk, V. K. & Dawson, J. M.
Object Type:
Article
System:
The UNT Digital Library
Dynamics and pattern selection at the crystal-melt interface. Progress report No. 4, March 1, 1989--February 28, 1990
This report discusses: light scattering at the crystal-melt interface; morphological instability and pattern selection; and sidebranching.
Date:
December 31, 1990
Creator:
Cummins, H. Z.
Object Type:
Report
System:
The UNT Digital Library
Effect of a low-permeability layer on calculated gas flow at Yucca Mountain
Yucca Mountain is being studied to determine its suitability as a location for a high-level nuclear waste repository. Amter and Ross developed a model called TGIF (Topographic Induced Flow) to simulate gas flow under Yucca Mountain. The TGIF model differs significantly from previous gas flow models. It uses a governing equation that is based on the concept of freshwater head, thus avoiding the numerical problems associated with the near-cancellation of the forces due to gravity and the pressure gradient. Unlike most other models, dipping, layered media can be simulated. This paper describes a systematic sensitivity study that was designed to test several aspects of the TGIF model when used to simulate gas flow under Yucca Mountain. Values of three important inputs to the model were systematically varied to form a matrix of 80 runs. The matrix consisted of five values of permeability contrast between a bedded tuff layer and surrounding welded units (in all cases, bulk permeabilities were used to represent the combined effect of both fractures and matrix permeability), four temperature profiles representing different stages of repository cooldown, and four finite-difference grids.
Date:
December 31, 1990
Creator:
Lu, Ning; Amter, S. & Ross, B.
Object Type:
Article
System:
The UNT Digital Library