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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

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

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, 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

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

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

Transverse stimulated Raman scattering in KDP

Description: Optical components of large-aperture, high irradiance and high fluence lasers can experience significant levels of stimulated scattering along their transverse dimensions. The authors have observed transverse stimulated Raman scattering in large aperture KDP crystals, and have measured the stimulated gain coefficient. With sufficiently high gain, transverse stimulated scattering can lead to energy loss from the main beam and, more importantly, optical damage in the components in which this scattering occurs. Thus transverse stimulated,scattering is of concern in large aperture fusion lasers such as Nova and Beamlet, which is a single-aperture, full-scale scientific prototype of the laser driver for the proposed National Ignition Facility.
Date: September 12, 1995
Creator: Barker, C.E.; Sacks, R.A.; Wonterghem, B.M. Van; Caird, J.A.; Murray, J.R.; Campbell, J.H. et al.
Partner: UNT Libraries Government Documents Department

Dust-gas interaction deduced from Halley multicolour camera observations

Description: The dust and gas productions of Comet Halley were measured by the dust counter and the mass spectrometers on the Giotto spacecraft. These instruments give only little information about the spatial asymmetry of the activity. The asymmetry in the dust production is clearly evident from the dust jets seen in the Halley Multicolour Camera images. Since the dust is entrained by the gas, production must be similarly asymmetric. The intensity profiles along and across several dust jets are related to their source regions on the nucleus. Properties of the dust jets are investigated. A few compact, but highly active source regions on the nucleus produce most of the visible dust and can account for most of the gas produced by the comet. 2 refs.
Date: January 1, 1986
Creator: Huebner, W.F.; Delamere, W.A.; Keller, H.U.; Reitsema, H.J.; Schmidt, H.U.; Whipple, F.L. et al.
Partner: UNT Libraries Government Documents Department

Results from geopressured-geothermal subsidence studies

Description: Benchmark networks have been installed around each of the US Department of Energy geopressured-geothermal test sites in southwestern Louisiana. These networks are periodically surveyed to detect subsidence which may be attributable to depressurization of the geopressured-geothermal reservoirs. The acquired leveling data have been adjusted to account for regional base-line movement determined in another study. The effects of geopressured-geothermal development can only be assessed after carefully examining other potential causes of subsidence. The histories of oil and gas production and ground-water withdrawal around the geopressured-geothermal test site at Parcperdue indicate that oil, gas, and ground-water production may contribute much more to anomalous subsidence than recent geopressured-geothermal brine production. A trend-surface analysis of leveling data for the Parcperdue test site allowed for the separation of a regional component of movement attributable to uplift in the Iberian structural axis to the east and subsidence above a Pleistocene depocenter to the west of the test site. Residual deviations from the regional trend may be associated with the temporary loading and compaction of surface soils caused by the weight of drilling equipment and with ground-water withdrawal.
Date: January 1, 1984
Creator: Trahan, D.B.
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

Acoustic imaging in a water filled metallic pipe

Description: A method is described for the imaging of the interior of a water filled metallic pipe using acoustical techniques. The apparatus consists of an array of 20 acoustic transducers mounted circumferentially around the pipe. Each transducer is pulsed in sequence, and the echos resulting from bubbles in the interior are digitized and processed by a computer to generate an image. The electronic control and digitizing system and the software processing of the echo signals are described. The performance of the apparatus is illustrated by the imaging of simulated bubbles consisting of thin walled glass spheres suspended in the pipe.
Date: April 1, 1984
Creator: Kolbe, W.F.; Turko, B.T. & Leskovar, B.
Partner: UNT Libraries Government Documents Department

Water vapor pressure gauge

Description: An inexpensive pressure gauge, able to measure the N/sub 2/ and H/sub 2/O components within a vacuum system in the pressure range 1..mu.. to 400..mu.. is described and results of tests of the device are reported.
Date: January 1, 1980
Creator: Edwards, D Jr & Gillette, D
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

Calibration of a neutron log in partially saturated media IV: effects of sonde-wall gap

Description: A gap between a neutron sonde and the wall of a borehole can have a significant effect on the observed count rate. This effect was determined experimentally to be linear with gaps as large as 2.5 cm. The count rate is given by N/sub N/ = K/sub 0/ + K/sub 1/g where K/sub 0/ is the count rate that would be observed at zero gap, and g is the gap. The parameters K/sub 0/ and K/sub 1/ are dependent on both water (ie. hydrogen) content and bulk density. In many situations failure to correct the count rate for this gap effect can result in a significant degradation in the accuracy of the water content calculated from the count rate. In a dry borehole, K/sub 1/ is small at zero formation water content, and increases with formation water content. In a water-filled borehole, K/sub 1/ is large at zero formation water content, and tends to decrease with increasing formation water content, becoming zero, as of course it must, if the formation is pure water. The absolute value of K/sub 1/ increases with increasing density. A representation was determined for K/sub 0/ and K/sub 1/ from experimental data. This representation can be used to adjust the count rate at a given gap to equal its zero-gap value. The accuracy of the zero gap equation can then be recovered.
Date: March 8, 1984
Creator: Axelrod, M.C. & Hearst, J.R.
Partner: UNT Libraries Government Documents Department