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Experimental Determination of Phase Equilibria in the System H{sub 2}O-CO{sub 2}-NaCl at 0.5 Kb from 500 to 800C

Description: An understanding of activity-composition (a/X) relations and phase equilibria for halite-bearing, mixed-species supercritical fluids is critically important to many geological and industrial applications. The authors have performed experiments on the phase equilibria of H{sub 2}O-CO{sub 2}-NaCl fluids from 500 C to 800 C at 500 bars, conditions of significant importance in studies of magma-hydrothermal systems, geothermal reservoirs and some ore deposits, to obtain highly accurate and precise data for this ternary system. These experiments are conducted using a double capsule technique. An excess of NaCl is placed in an inner Pt capsule, which is crimped shut and placed in an outer capsule containing H{sub 2}O and CO{sub 2}. During the experiment NaCl dissolves out of the inner capsule, and is deposited in the outer capsule during the quench. After the experiment the capsule is opened, and the amount of NaCl remaining in the inner capsule determined by dissolution. The difference between the initial and final amounts of NaCl in the inner capsule yields the solubility of NaCl at the P-T conditions of the experiment. At 500 C data from these experiments suggest that the vapor comer of the three-phase field lies near X(H{sub 2}O) = 0.760, X(NaCl) = 0.065, which is a significantly more water-rich composition than suggested by previous models. As expected, increasing temperature increases the solubility of NaCl in the NaCl-vapor field. For example, at intermediate H{sub 2}O/CO{sub 2} ratios the vapor field extends from approximately near X(H{sub 2}O) = 0.66, X(NaCl) = 0.06 at 500 C to near X(H{sub 2}O) = 0.65, X(NaCl) = 0.08 at 600 C.
Date: January 9, 2001
Creator: Anovitz, L.M.
Partner: UNT Libraries Government Documents Department

Development of the Hybrid Sulfur Thermochemical Cycle

Description: The production of hydrogen via the thermochemical splitting of water is being considered as a primary means for utilizing the heat from advanced nuclear reactors to provide fuel for a hydrogen economy. The Hybrid Sulfur (HyS) Process is one of the baseline candidates identified by the U.S. Department of Energy [1] for this purpose. The HyS Process is a two-step hybrid thermochemical cycle that only involves sulfur, oxygen and hydrogen compounds. Recent work has resulted in an improved process design with a calculated overall thermal efficiency (nuclear heat to hydrogen, higher heating value basis) approaching 50%. Economic analyses indicate that a nuclear hydrogen plant employing the HyS Process in conjunction with an advanced gas-cooled nuclear reactor system can produce hydrogen at competitive prices. Experimental work has begun on the sulfur dioxide depolarized electrolyzer, the major developmental component in the cycle. Proof-of-concept tests have established proton-exchange-membrane cells (a state-of-the-art technology) as a viable approach for conducting this reaction. This is expected to lead to more efficient and economical cell designs than were previously available. Considerable development and scale-up issues remain to be resolved, but the development of a viable commercial-scale HyS Process should be feasible in time to meet the commercialization schedule for Generation IV gas-cooled nuclear reactors.
Date: September 23, 2005
Creator: Summers, William A. & Steimke, John L
Partner: UNT Libraries Government Documents Department

Multistage metal hydride compressor

Description: Metal hydride compressors can compress hydrogen to high pressures without using mechanical moving parts. They are particularly suited for tritium applications because they require minimal maintenance. A three-stage metal hydride compressor which can compress hydrogen from 14.7 to 20,000 psia has been demonstrated. The design principle and experimental results are presented.
Date: January 1, 1986
Creator: Heung, L.K.
Partner: UNT Libraries Government Documents Department

Isotopic HCl transfer laser

Description: An HCl laser which uses isotopic V-V energy transfer collisions as a pumping mechanism has been demonstrated. This multiline laser, which utilized an intracavity cold gas isotope filter, increased the energy from the P/sub 1/ lines of H/sup 37/Cl while decreasng the energies of the P/sub 1/ and P/sub 2/ lines of H/sup 35/Cl. Previously unreported lines, including emission from R branch transitions, have also been observed from single-line HCl and HBr lasers.
Date: December 15, 1977
Creator: Badcock, C.C.; Hwang, W.C.; Kalsch, J.F. & Kamada, R.F.
Partner: UNT Libraries Government Documents Department

Investigation into the high strain-rate behavior of compacted sand using the split-Hopkinson pressure bar technique

Description: The results of compressive high strain-rate experiments on compacted sand are presented. Experiments were conducted on a 60.3 mm split Hopkinson pressure bar (SHPB). The experiments showed that the assumptions necessary for a valid SHPB experiment are satisfied when using compacted sand samples constrained to a nearly uniaxial strain state. Results show that the sample stress-strain response is governed principally by the initial sample gas porosity, and that no strain-rate dependence is exhibited at sample strains less than the initial gas porosity. Several stress-strain curves are presented for samples prepared at several combinations of moisture content and density with applied stresses and strain rates up to 520 MPa and 4000 sec/sup -1/, respectively.
Date: January 1, 1985
Creator: Felice, C.W.; Brown, J.A.; Gaffney, E.S. & Olsen, J.M.
Partner: UNT Libraries Government Documents Department

Deburring: technical capabilities and cost-effective approaches, Lessons 9 and 10

Description: Abrasive jet, water jet, and abrasive flow deburring are not panaceas for the world's deburring problems. They do, however, solve many of the problems where burrs are either difficult to reach or amenable to automation. As seen in this lesson, they can deburr miniature parts as well as large parts. In almost every case; however, one will note that accessibility of the burr is the key to the success of these processes. Volumes have been published on the effects of abrasive jet parameters. The reader is encouraged to pursue some of the citations in the Source of Additional Information for further quantitative information. Similarly, data on abrasive flow deburring is also available. Little data, however, has been published on water jet deburring.
Date: June 1, 1980
Creator: Gillespie, LaRoux K.
Partner: UNT Libraries Government Documents Department

Microstructure of amorphous-silicon-based solar cell materials by small-angle x-ray scattering. Annual technical report, April 6, 1995--April 5, 1996

Description: The objective of this project is to provide detailed microstructural information on the amorphous silicon based thin film materials under development for improved multijunction solar cells. Correlation of microstructure with opto-electrical properties and device performance is an integral part of the research. During this second phase of our three-year program we have obtained information on the microstructure of materials relevant to the Low-, Mid-, and High-bandgap Teams and the results are appropriately divided into these three types of material as presented below. The experimental methods, data analysis, and interpretation procedures are the same as those described in detail in the phase-one report and in the review paper published last year.
Date: August 1, 1996
Creator: Williamson, D.L.
Partner: UNT Libraries Government Documents Department

General Chemistry Technical Note No. 71: Hydrogen compounds of low atomic weight

Description: This report provides a compilation of Hydrogen compounds of low atomic weight. Compounds known and reported in literature are given. Cations and anions of high Hydrogen content and/or low Z are provided as are molecules which form Lewis salts. Finally, unknown compounds for which synthesis seems probable are given.
Date: March 30, 1962
Creator: Pearson, R. K.
Partner: UNT Libraries Government Documents Department

Advanced alkaline water electrolysis. Task 2 summary report. Model for alkaline water electrolysis systems

Description: Task 2 involved the establishment of an engineering and economic model for the evaluation of various options in water electrolysis. The mode, verification of the specific coding and four case studies are described. The model was tested by evaluation of a nearly commercial technology, i.e., an 80-kW alkaline electrolyte system, operating at 60/sup 0/C, which delivers approximately 255 SLM, hydrogen for applications such as electrical generation cooling or semiconductor manufacturing. The calculated cost of hydrogen from this installed non-optimized case system with an initial cost to the customer of $87,000 was $6.99/Kg H/sub 2/ ($1.67/100 SCF) on a 20-yr levelized basis using 2.5 cents/kWh power costs. This compares favorably to a levelized average merchant hydrogen cost value of $9.11/Kg H/sub 2/ ($2.17/100 SCF) calculated using the same program.
Date: April 1, 1980
Creator: Yaffe, M.R. & Murray, J.N.
Partner: UNT Libraries Government Documents Department

Subsurface flow and transport of organic chemicals: an assessment of current modeling capability and priority directions for future research (1987-1995)

Description: Theoretical and computer modeling capability for assessing the subsurface movement and fate of organic contaminants in groundwater was examined. Hence, this study is particularly concerned with energy-related, organic compounds that could enter a subsurface environment and move as components of a liquid phase separate from groundwater. The migration of organic chemicals that exist in an aqueous dissolved state is certainly a part of this more general scenario. However, modeling of the transport of chemicals in aqueous solution has already been the subject of several reviews. Hence, this study emphasizes the multiphase scenario. This study was initiated to focus on the important physicochemical processes that control the behavior of organic substances in groundwater systems, to evaluate the theory describing these processes, and to search for and evaluate computer codes that implement models that correctly conceptualize the problem situation. This study is not a code inventory, and no effort was made to identify every available code capable of representing a particular process.
Date: September 1, 1986
Creator: Streile, G.P. & Simmons, C.S.
Partner: UNT Libraries Government Documents Department

Uranium from phosphate ores

Description: The following topics are described briefly: the way phosphate fertilizers are made; how uranium is recovered in the phosphate industry; and how to detect covert uranium recovery operations in a phsophate plant.
Date: January 1, 1983
Creator: Hurst, F.J.
Partner: UNT Libraries Government Documents Department

Thermal simulation of quenching uranium-0. 75% titanium alloy in water

Description: A computer model, The Quench Simulator, has been developed to simulate and predict in detail the behavior of U-0.75 Ti alloy when quenched at high temperature (about 850/sup 0/C) in cold water. The code allows one to determine the time- and space-dependent distributions of temperature, residual stress, distortion, and microstructure that evolve during the quenching process. The nonlinear temperature- and microstructure-dependent properties, as well as the cooling rate-dependent heats of transformation, are incorporated into the model. The complex boiling heat transfer with its various regimes and other thermal boundary conditions are simulated. Experiments have been performed and incorporated into the model. Both sudden submersion and gradual controlled immersion can be applied. A parametric and sensitivity study has been performed demonstrating the importance of the thermal boundary conditions applied for achieving certain product characteristics. The thermal aspects of the model and its applications are discussed and demonstrated.
Date: January 1, 1985
Creator: Siman-Tov, M.; Llewellyn, G.H.; Childs, K.W.; Ludtka, G.M. & Aramayo, G.A.
Partner: UNT Libraries Government Documents Department

Determination of the location and connectivity of fractures in metamorphic rock with in-hole tracers

Description: In-hole tracer tests were used in a geohydrologic investigation of metamorphic rock at the Savannah River Plant near Aiken, SC to locate water-transmitting fractures and to determine the connectivity of these fractures between boreholes. Only after development of a conceptual model of the fracture occurrence and connection could the proper methods of analysis for the hydraulic parameters be selected. In-hole tracers were used to locate fractures in a borehole and supplemented other methods, such as core inspection, geophysical logs, borehole wall imaging techniques, dry drilling, and packer tests. The first three of these do not necessarily investigate fluid-transmitting fractures. In the study of the connectivity of fractures between boreholes, the in-hole tracer techniques supplemented determinations by the rapidity of hydraulic response and the use of between-well tracer tests. In hydraulically transmissive rock, fractures were located by changes in the velocity of the tracer pulse in response to adding fluid to the well. In virtually impermeable rock, the movement of the tracer pulse in the rock was normalized to the movement of another tracer pulse in the cased portion of the well because the movement was so slow that direct measurement was difficult. Connectivity of fractures between boreholes was determined by placing an in-hole tracer in one hole and measuring the movement induced by pumping a nearby borehole. From this test, it was determined that the fractures were interlacing, and single fractures did not extend from one borehole directly to the other.
Date: January 1, 1979
Creator: Marine, I.W.
Partner: UNT Libraries Government Documents Department

Internal dosimetry of tritium

Description: Tritium is an interesting radionuclide from the perspective of internal dosimetry because of the wide variety of chemical compounds in which it can appear, its unusual routes of entry into the body, and its ability to exchange with stable hydrogen in surrounding material. In this report the internal dosimetry of tritium compounds is reviewed, with emphasis on methods of evaluating bioassay data following chronic and acute intakes. The assumptions and models used in the derivation of Annual Limits on Intake (ALI) and Derived Air Concentrations (DAC) for tritium are also discussed.
Date: January 1, 1992
Creator: LaBone, T.R.
Partner: UNT Libraries Government Documents Department

Uranium oxidation: characterization of oxides formed by reaction with water

Description: Three different uranium oxide samples have been characterized with respect to the different preparation techniques. Results show that the water reaction with uranium metal occurs cyclically forming laminar layers of oxide which spall off due to the strain at the oxide/metal interface. Single laminae are released if liquid water is present due to the prizing penetration at the reaction zone. The rate of reaction of water with uranium is directly proportional to the amount of adsorbed water on the oxide product. Rapid transport is effected through the open hydrous oxide product. Dehydration of the hydrous oxide irreversibly forms a more inert oxide which cannot be rehydrated to the degree that prevails in the original hydrous product of uranium oxidation with water. 27 figures.
Date: April 27, 1983
Creator: Fuller, E.L. Jr.; Smyrl, N.R.; Condon, J.B. & Eager, M.H.
Partner: UNT Libraries Government Documents Department

Pulsed hydrojet propulsion

Description: The pulsed hydrojet is a device in which the water ingested from the free stream is accelerated out of the exhaust pipe to produce thrust. In this report we describe and analyze a way of accelerating the stream of water with pockets of high pressure steam and gas generated inside the stream by an exothermal reaction of suitable propellant injected and dispersed in the water. The velocity increment that must be imparted to the water to produce a substantial thrust need not be very large because the density of the water is comparable to the average density of the accelerated body. Results of the numerical modeling of the proposed jet acceleration mechanism indicate that the hydrojet propulsion device is potentially capable of propelling underwater projectiles at speeds three to five times greater than those currently attainable. Several promising applications of the hydrojet thruster are discussed and evaluated.
Date: January 1, 1985
Creator: Bohachevsky, I.O. & Torrey, M.D.
Partner: UNT Libraries Government Documents Department

Effects of phase transformation of steam-water relative permeabilities

Description: A combined theoretical and experimental study of steam-water relative permeabilities (RPs) was carried out. First, an experimental study of two-phase concurrent flow of steam and water was conducted and a set of RP curves was obtained. These curves were compared with semi-empirical and experimental results obtained by other investigators for two-phase, two-component flow (oil/gas; gas/water; gas/oil). It was found that while the wetting phase RPs were in good agreement, RPs for the steam phase were considerably higher than the non-wetting phase RPs in two-component systems. This enhancement of steam RP is attributed to phase transformation effects at the pore level in flow channels. The effects of phase transformation were studied theoretically. This study indicates that there are two separate mechanisms by which phase transformation affects RP curves: (1) Phase transformation is converging-diverging flow channels can cause an enhancement of steam phase RP. In a channel dominated by steam a fraction of the flowing steam condenses upstream from the constriction, depositing its latent heat of condensation. This heat is conducted through the solid grains around the pore throat, and evaporation takes place downstream from it. Therefore, for a given bulk flow quality; a smaller fraction of steam actually flows through the throat segments. This pore-level effect manifests itself as relative permeability enhancement on a macroscopic level; and (2) phase transformation along the interface of a stagnant phase and the phase flowing around it controls the irreducible phase saturation. Therefore, the irreducible phase saturation in steam-water flow will depend, among other factors, on the boundary conditions of the flow.
Date: March 1, 1986
Creator: Verma, A.K.
Partner: UNT Libraries Government Documents Department