Degree Discipline

Degree Level

UNLV Information Science Research Institute quarterly progress report (open access)

UNLV Information Science Research Institute quarterly progress report

This report presents research on information systems, information retrieval, and optical character recognition. (CBS)
Date: December 31, 1991
Creator: Nartker, T.A.
Object Type: Report
System: The UNT Digital Library
Sulfur removal in advanced two stage pressurized fluidized bed combustion. Technical report, September 1--November 30, 1994 (open access)

Sulfur removal in advanced two stage pressurized fluidized bed combustion. Technical report, September 1--November 30, 1994

The objective of this study is to obtain data on the rates and the extent of sulfation reactions involving partially sulfided calcium-based sorbents, and oxygen as well as sulfur dioxide, at operating conditions closely simulating those prevailing in the second stage (combustor) of Advanced Two-Stage Pressurized Fluidized-Bed Combustors (PFBC). In these systems the CO{sub 2} partial pressure generally exceeds the equilibrium value for calcium carbonate decomposition. Therefore, calcium sulfate is produced through the reactions between SO{sub 2} and calcium carbonate as well as the reaction between calcium sulfide and oxygen. To achieve this objective, the rates of reaction involving SO{sub 2} and oxygen (gaseous reactant); and calcium sulfide and calcium carbonate (solid reactants), will be determined by conducting tests in a pressurized thermogravimetric analyzer (HPTGA) unit. The effects of sorbent type, sorbent particle size, reactor temperature and pressure; and O{sub 2} as well as SO{sub 2} partial pressures on the sulfation reactions rate will be determined. During this quarter, samples of the selected limestone and dolomite were sulfided in the fluidized-bed reactor. These tests were conducted in both calcining and non-calcining operating conditions to produce partially-sulfided sorbents containing calcium oxide and calcium carbonate, respectively. These samples which represent the carbonizer …
Date: December 31, 1994
Creator: Abbasian, Javad; Hill, Andy; Wangerow, James R. & Honea, Franklin I.
Object Type: Report
System: The UNT Digital Library
Geothermal Education Office summary report: First year of operations, January 1, 1990--December 31, 1990 (open access)

Geothermal Education Office summary report: First year of operations, January 1, 1990--December 31, 1990

Our mission for 1990 was to increase students' awareness and appreciation of geothermal energy with respect to both direct use and electrical power production.'' Hard work has accomplished much: using both responsive and pro-active techniques, the Geothermal Education Office has had national impact on K-12 curriculum as well as on general public awareness of geothermal energy.
Date: December 31, 1990
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The development and testing of a fieldworthy system of improved fluid pumping device and liquid sensor for oil wells (open access)

The development and testing of a fieldworthy system of improved fluid pumping device and liquid sensor for oil wells

A major expenditure to maintain oil and gas leases is the support of pumpers, those individuals who maintain the pumping systems on wells to achieve optimum production. Many leases are marginal and are in remote areas and this requires considerable driving time for the pumper. The Air Pulse Oil Pump System is designed to be an economical system for the shallow stripper wells. To improve on the economics of this system, we have designed a Remote Oil Field Monitor and Controller to enable us to acquire data from the lease to our central office at anytime and to control the pumping activities from the central office by using a personal computer. The advent and economics of low-power microcontrollers have made it feasible to use this type of system for numerous remote control systems. We can also adapt this economical system to monitor and control the production of gas wells and/or pump jacks.
Date: December 31, 1991
Creator: Buckman, W.G.
Object Type: Report
System: The UNT Digital Library
Maintaining the uranium resources data system and assessing the 1989 US uranium potential resources (open access)

Maintaining the uranium resources data system and assessing the 1989 US uranium potential resources

Under the Memorandum of Understanding (MOU) between the EIA, US Department of Energy, and the US Geological Survey (USGS), US Department of the Interior, the USGS develops estimates of uranium endowment for selected geological environments in the United States. New estimates of endowment are used to update the Uranium Resources Assessment Data (URAD) System which, beginning in 1990, is maintained for EIA by the USGS. For 1989, estimates of US undiscovered resources were generated using revised economic index values (current to December 1989) in the URAD system's cost model. The increase in the estimates for the Estimated Additional Resources (EAR) and Speculative Resources (SR) classes resulted primarily from increases in the estimates of uranium endowment for the solution-collapse, breccia-pipe uranium deposit environment in the Colorado Plateau resource region. The mean values for $30-, $50-, and $100-per-pound U{sub 3}O{sub 8} forward-cost categories of EAR increased by about 8, 48, and 32 percent, respectively, as compared to 1988. Estimates of the 1989 undiscovered resources in the SR class also increased in all three forward-cost categories by 10, 5, and 9 percent, respectively. The original cost equations in the URAD System were designed to cover drilling costs related to extensive flat-lying tabular ore …
Date: December 31, 1990
Creator: McCammon, R. B. (Geological Survey, Reston, VA (USA)); Finch, W. I.; Grundy, W. D. & Pierson, C. T. (Geological Survey, Denver, CO (USA))
Object Type: Report
System: The UNT Digital Library
Radiolabelled D2 agonists as prolactinoma imaging agents (open access)

Radiolabelled D2 agonists as prolactinoma imaging agents

Research conducted in this terminal year of support centered on three distinct areas: mAChR ligand localization in pancreas and the effect of Ca{sup +2} on localization, continuation of assessment of quaternized and neutral mAChR ligands for possible use as PET myocardial imaging agents, and initiation of a study to determine the relationship of the nAChR receptor to the cellular receptor for measles virus. Several tables and figures illustrating the results are included.
Date: December 31, 1991
Creator: Otto, C. A.
Object Type: Report
System: The UNT Digital Library
A miniature inexpensive, oxygen sensing element (open access)

A miniature inexpensive, oxygen sensing element

Current progress on the development of the oxygen sensor is reviewed. During this quarter the sensor seal and heating element was redesigned and prototypes were tested. A combustor experiment will be performed in the next one to two quarters. Related information on lean sensors is also reviewed. Additional testing was done on multilayer sensors pulled from storage. (SM)
Date: December 31, 1990
Creator: Arenz, R.W.
Object Type: Report
System: The UNT Digital Library
Maintaining the uranium resources data system and assessing the 1991 US uranium potential resources (open access)

Maintaining the uranium resources data system and assessing the 1991 US uranium potential resources

The Energy Information Administration's (EIA) Uranium Resource Assessment Data (URAD) System contains information on potential resources (undiscovered) of uranium in the United States. The purpose of this report is: (1) to describe the work carried out to maintain and update the URAD system; (2) to assess the 1991 U.S. uranium potential resources in various cost categories; and (3) to describe the progress that has been made to automate the generation of the assessment reports and their subsequent transmittal by diskette.
Date: December 31, 1992
Creator: McCammon, R. B. (Geological Survey, Reston, VA (United States)); Finch, W. I.; Grundy, W. D. & Pierson, C. T. (Geological Survey, Denver, CO (United States))
Object Type: Report
System: The UNT Digital Library
Removal of deuterium from flowing nitrogen by SAES St 198 (open access)

Removal of deuterium from flowing nitrogen by SAES St 198

Testing was conducted to investigate the ability of a metal getter, SAES St 198, to remove D[sub 2] from flowing nitrogen. This getter is being considered for applications involving removal of tritium at low concentrations from glovebox atmospheres and inert or nitrogen process streams. This document reports results from tests involving flow of 107 ppM D[sub 2] in nitrogen through a packed bed of St 198 getter granules (1.02 mm average dia) at a gas flow rate of 400 std. cm[sup 3][center dot]min[sup [minus]1]. The first of two tests (Run 1) was conducted at a temperature of 350[degrees]C, and the getter reactor contained 9.7 grams of getter. The second test (Run 2) was at 250[degrees]C, and the reactor contained 5.1 grams of getter. The tests involved continuous flow of the D[sub 2]/N[sub 2] mixture into the getter bed for several days, during which the inlet and outlet streams were analyzed for D[sub 2] by mass spectrometry at 12 h intervals. For both runs, testing continued until nearly complete breakthrough of deuterium was observed. During Run 1 no D[sub 2] was detected in the getter bed exit stream for 122 h, and during Run 2, no D[sub 2] was detected in …
Date: December 31, 1992
Creator: Nobile, A.
Object Type: Report
System: The UNT Digital Library
[Physicochemical and microbiological factors influencing the bioavailability of organic contaminants in subsoils] (open access)

[Physicochemical and microbiological factors influencing the bioavailability of organic contaminants in subsoils]

We report progress in elucidating the microbiological variables important in determining the relative success of bacteria in utilizing soil-sorbed contaminants. Two bacterial species, Pseudomonas putida (ATCC 17484) and an Alcaligenes sp. isolated from petroleum contaminated soil are known to differ markedly in their ability to utilize soil-sorbed napthalene based on a kinetic comparison of their capability of naphthalene mineralization in soil-containing and soil-free systems. The kinetic analysis led us to conclude that strain 17484 had direct access to naphthalene present in a labile sorbed state which promoted the rapid desorption of naphthalene from the non-labile phase. Conversely, both the rate and extent of naphthalene mineralization by strain NP-Alk suggested that this organism had access only to naphthalene in solution. Desorption was thus limited and the efficiency of total naphthalene removal from these soil slurries was poor. These conclusions were based on the average activities of cells in soil slurries without regard for the disposition of the organisms with respect to the sorbent. Since both organisms degrade naphthalene by apparently identical biochemical pathways, have similar enzyme kinetic properties, and are both motile, gram negative organisms, we undertook a series of investigations to gain a better understanding of what microbiological properties were …
Date: December 31, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Synthesis and analysis of novel polymers with high permselectivity and permeability in gas separation applications (open access)

Synthesis and analysis of novel polymers with high permselectivity and permeability in gas separation applications

Significant progress was made toward developing advanced materials for gas separation membrane applications and rationalizing molecular structure and efficacy: Synthesized and tested polyarylates based on terephthalic or isophthalic acid or a tertiary butyl derivative of the isophthalic acid with different diols to illustrate the effects of: opening'' the matrix by incorporation of bulky packing inhibiting groups such as the tertiary butyl moiety inhibition of backbone motion via meta connected backbone connections and tightening'' of the matrix by incorporation of polar halogens. Completed high temperature characterization of sorption and transport properties for novel materials. Continued studies of the phenyl-substituted polymers aimed at producing super stable high temperature useful polymers for gas separations. Synthesized a polyarylate based on the spirobiindane diol and bibenzoyl acid chloride to incorporate long flat packable bibenzoyl units between packing disruptive spirobiindane units in an attempt to control the segmental level morphology to produce highly selective bottleneck'' regions between highly open regions.
Date: December 31, 1991
Creator: Koros, W. J. & Paul, D. R.
Object Type: Report
System: The UNT Digital Library
Advanced turbine cooling, heat transfer, and aerodynamic studies (open access)

Advanced turbine cooling, heat transfer, and aerodynamic studies

The contractual work is in three parts: Part I - Effect of rotation on enhanced cooling passage heat transfer, Part II - Effect of Thermal Barrier Coating (TBC) spallation on surface heat transfer, and Part III - Effect of surface roughness and trailing edge ejection on turbine efficiency under unsteady flow conditions. Each section of this paper has been divided into three parts to individually accommodate each part. Part III is further divided into Parts IIIa and IIIb.
Date: December 31, 1995
Creator: Han, Je-Chin & Schobeiri, Meinhard T.
Object Type: Article
System: The UNT Digital Library
Texas Attorney General Opinion: DM-194 (open access)

Texas Attorney General Opinion: DM-194

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Dan Morales, regarding a legal question submitted for clarification: Whether a home rule city may sponsor a non-profit, no-share corporation, and related questions (RQ-441)
Date: December 31, 1992
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Disilene Addition to C{sub 70} (open access)

Disilene Addition to C{sub 70}

Semiempirical and ab initio Hartree Fock computational results indicate that the highly reactive dienophile tetramethyldisilene, Me{sub 2}Si=SiMe{sub 2}, is an excellent candidate for a novel functionalization of the equator of C{sub 70} via a [2+4] cycloaddition to the 21, 22, 23, 42 carbons. Thermal or photochemical generation of tetramethyldisilene in the presence of C{sub 70} results in similar complex mixtures in which the major product appears to be that of [2+2] cycloaddition to the 7,8 carbons of C{sub 70}. A minor product clearly results from [2+2] cycloaddition to the 1,9 carbons. Both of these products are hydrolytically unstable and are converted nonspecifically to mixtures of 1,9- and 7,8-C{sub 70}H{sub 2} which are also present in HPLC traces of the reaction mixtures.
Date: December 31, 1994
Creator: Jacobs, S. J.; Cahill, P. A. & Rohlfing, C. M.
Object Type: Article
System: The UNT Digital Library
Study of heavy flavored particles. Progress report (open access)

Study of heavy flavored particles. Progress report

This report discusses progress on the following topics: time-of- flight system; charmed baryon production and decays; D decays to baryons; measurement of sigma plus particles magnetic moments; and strong interaction coupling. (LSP)
Date: December 31, 1991
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Mass transport through polycrystalline microstructures (open access)

Mass transport through polycrystalline microstructures

Mass transport properties are important in polycrystalline materials used as protective films. Traditionally, such properties have been studied by examining model polycrystalline structures, such as a regular array of straight grain boundaries. However, these models do not account for a number of features of real grain ensembles, including the grain size distribution and variations in grain shape. In this study, a finite difference scheme is developed to study transient and steady-state mass transport through realistic two dimensional polycrystalline microstructures. Comparisons with the transport properties of traditional model microstructures provide regimes of applicability of such models. The effects of microstructural parameters such as average grain size are examined.
Date: December 31, 1994
Creator: Swiler, T. P.; Holm, E. A.; Young, M. F. & Wright, S. A.
Object Type: Report
System: The UNT Digital Library
Pilot gasification and hot gas cleanup operations (open access)

Pilot gasification and hot gas cleanup operations

The Morgantown Energy Technology Center (METC) has an integrated gasification hot gas cleanup facility to develop gasification, hot particulate and desulfurization process performance data for IGCC systems. The objective of our program is to develop fluidized-bed process performance data for hot gas desulfurization and to further test promising sorbents from lab-scale screening studies at highpressure (300 psia), and temperatures (1,200{degrees}F) using coal-derived fuel gases from a fluid-bed gasifier. The 10-inch inside diameter (ID), nominal 80 lb/hr, air blown gasifier is capable of providing about 300 lb/hr of low BTU gas at 1,000{degrees}F and 425 psig to downstream cleanup devices. The system includes several particle removal stages, which provide the capability to tailor the particle loading to the cleanup section. The gas pressure is reduced to approximately 300 psia and filtered by a candle filter vessel containing up to four filter cartridges. For batch-mode desulfurization test operations, the filtered coal gas is fed to a 6-inch ID, fluid-bed reactor that is preloaded with desulfurization sorbent. Over 400 hours of gasifier operation was logged in 1993 including 384 hours of integration with the cleanup rig. System baseline studies without desulfurization sorbent and repeatability checks with zinc ferrite sorbent were conducted before testing …
Date: December 31, 1995
Creator: Rockey, John M.; Galloway, Edwin; Thomson, Teresa A.; Rutten, Jay & Lui, Alain
Object Type: Article
System: The UNT Digital Library
Heavy duty gas turbine combustion tests with simulated low BTU coal gas (open access)

Heavy duty gas turbine combustion tests with simulated low BTU coal gas

There is an increasing industry interest in integrated gas turbine combined cycle plants in which coal gasifiers provide the fuel for the gas turbines. Some gasifier plant designs, including the air-blown processes, some integrated oxygen blown processes and some oxygen-blown processes followed by heavy moisturization, produce fuel gases which have lower heating values ranging from 130 to below 100 BTU/scf for which there is little gas turbine combustion experience. This program has the objectives to: Parametrically determine the effects of moisture, nitrogen and carbon dioxide as diluents so that the combustion characteristics of many varieties of gasification product gases can be reasonably predicted without physically testing each specific gas composition; determine emissions characteristics including NO{sub x}, CO, levels etc. associated with each of the diluents; operate with two syngas compositions; DOE chosen air-blown and integrated oxygen-blown, to confirm that the combustion characteristics are in line with predictions; determine if ``logical`` refinements to the fuel nozzle will yield improved performance for LBTU fuels; determine the conversion rate of ammonia to NO{sub x}; determine the effects of methane inclusion in the fuel.
Date: December 31, 1992
Creator: Ekstrom, T. E.; Battista, R. A. & Maxwell, G. P.
Object Type: Article
System: The UNT Digital Library
Modeling for Process Control. Progress Report (open access)

Modeling for Process Control. Progress Report

Significant developments have taken place in the control field during the last decade but their impact on industrial control practice has fallen far short of their full potential. One key difficulty that stands in the way of these new techniques is the need for process models. Work to be carried out under this grant aims at the development of a broad range of novel modeling and identification techniques which specifically address both information requirements of the new control analysis and design tools as well as the needs of the practicing control engineer.
Date: December 31, 1991
Creator: Morari, M.
Object Type: Report
System: The UNT Digital Library
[Investigation of transitions from order to chaos in dynamical systems]. Annual progress report (open access)

[Investigation of transitions from order to chaos in dynamical systems]. Annual progress report

This report discusses: torus structure in higher dimensional hamiltonian systems; particle heating and stochastic web diffusion; scaling behavior of coupled conservative nonlinear systems; box counting algorithm and dimensional analysis of a pulsar; and universality of coupled nonlinear systems. (LSP)
Date: December 31, 1990
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Further studies of the effects of oxidation on the surface properties of coal and coal pyrite (open access)

Further studies of the effects of oxidation on the surface properties of coal and coal pyrite

The objective of this research was to investigate the oxidation behavior of coal and coal pyrite and to correlate the changes in the surface properties induced by oxidation, along with the intrinsic physical and chemical properties of these organic and inorganic materials, with the behavior in physical coal cleaning processes. This provide more fundamental knowledge for understanding the way in which different factors interact in a medium as heterogeneous as coal. Fourteen coal samples of different ranks ranging from high to medium sulfur content were studied by dry oxidation tests at different temperatures and humidities, and by wet oxidation tests using different oxidizing agents. The concentration of surface oxygen functional groups was determined by ion-exchange methods. The changes in the coal composition with oxidation were analyzed by spectroscopic techniques. The wettability of as-received and oxidized coal and coal pyrite samples was assessed by film flotation tests. The electrokinetic behavior of different coals and coal pyrite samples was studied by electrokinetic tests using electrophoresis. Possible oxidation mechanisms have been proposed to explain the changes on the coal surface induced by different oxidation treatments.
Date: December 31, 1994
Creator: Herrera, Miguel Nicholas
Object Type: Thesis or Dissertation
System: The UNT Digital Library
An improvement in the modified finite element procedure for underwater shock analysis (open access)

An improvement in the modified finite element procedure for underwater shock analysis

The modified finite element procedure for underwater shock analysis decomposes the total pressure field into the incident, reflected and radiated pressure. The incident pressure is calculated by using a closed form solution. The reflected and radiated pressure are calculated in two separate finite element analyses. Artificial damping is added in the finite element analyses. Since these two pressures are generated from the fluid-structure interface and mostly propagate away from the interface, the artificial damping has no significant effect on the result. The modified finite element procedure was developed using a displacement formulated finite element to model the fluid region. In the paper, a pressure formulated finite element is used to model the fluid region which has a potential of saving 90 percent of the computer time. In doing so, the reflected and radiated pressure are calculated in one analysis which greatly simplifies the analysis procedure and saves more computer time. Two verification examples are given.
Date: December 31, 1992
Creator: Chan, S. K.
Object Type: Article
System: The UNT Digital Library
FLASH predictions of the MB-2 steam line break tests (open access)

FLASH predictions of the MB-2 steam line break tests

If a main steam line from a pressurized water reactor (PWR) steam generator were to rupture, the effect would be a depressurization of the secondary side and a consequential overcooling transient on the primary side. Analyses must accurately predict the effects of the rapid cooldown of the reactor vessel coolant on positive nuclear-kinetic reactivity feedback to the core plus thermal shock to the reactor vessel and other primary system components. Many early studies of the steam line break (SLB) transient made extremely conservative assumptions to maximize the primary to secondary heat transfer which in turn maximized the reactor vessel cooldown rate. Among the more significant of these assumptions was that flow from the break was pure steam and that the tube bundle remained covered until the secondary mass inventory was significantly reduced. The Model F commercial PWR steam generator testing performed in the Model Boiler No. 2 (MB-2) facility located at the Westinghouse Engineering Test Facility in Tampa, Florida provided data to better qualify the actual variation in these key parameters. A conclusion of this analysis is that the MB-2 steam line break data base is accurate and of sufficient detail to provide a valuable basis for making comparisons relative …
Date: December 31, 1992
Creator: Lincoln, F. W.; Coffield, R. D. & Johnson, E. G.
Object Type: Article
System: The UNT Digital Library
Polarized protons in large center of mass collisions (open access)

Polarized protons in large center of mass collisions

We present a scheme for polarized proton operation in the RHIC collider complex. For low energies the partial siberian snake project in the AGS is reviewed. As the energy is increased the difficulties of preserving the polarization also increases. A plan for preserving the polarization at high energies in RHIC using two Siberian Snakes is discussed. Spin rotators will be used around the collision points so that the helicity can be varied.
Date: December 31, 1992
Creator: Tepikian, S.
Object Type: Article
System: The UNT Digital Library