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Sample records for high temperature brines

  1. Geochemistry of Aluminum in High Temperature Brines

    SciTech Connect

    Benezeth, P.; Palmer, D.A.; Wesolowski, D.J.

    1999-05-18

    The objective ofthis research is to provide quantitative data on the equilibrium and thermodynamic properties of aluminum minerals required to model changes in permeability and brine chemistry associated with fluid/rock interactions in the recharge, reservoir, and discharge zones of active geothermal systems. This requires a precise knowledge of the thermodynamics and speciation of aluminum in aqueous brines, spanning the temperature and fluid composition rangesencountered in active systems. The empirical and semi-empirical treatments of the solubility/hydrolysis experimental results on single aluminum mineral phases form the basis for the ultimate investigation of the behavior of complex aluminosilicate minerals. The principal objective in FY 1998 was to complete the solubility measurements on boehmite (AIOOH) inNaC1 media( 1 .O and 5.0 molal ionic strength, IOO-250°C). However, additional measurements were also made on boehmite solubility in pure NaOH solutions in order to bolster the database for fitting in-house isopiestic data on this system. Preliminary kinetic Measurements of the dissolution/precipitation of boehmite was also carried out, although these were also not planned in the earlier objective. The 1999 objectives are to incorporate these treatments into existing codes used by the geothermal industry to predict the chemistry ofthe reservoirs; these calculations will be tested for reliability against our laboratory results and field observations. Moreover, based on the success of the experimental methods developed in this program, we intend to use our unique high temperature pH easurement capabilities to make kinetic and equilibrium studies of pH-dependent aluminosilicate transformation reactions and other pH-dependent heterogeneous reactions.

  2. Modeling Coupled THM Processes and Brine Migration in Salt at High Temperatures

    SciTech Connect

    Rutqvist, Jonny; Blanco-Martin, Laura; Molins, Sergi; Trebotich, David; Birkholzer, Jens

    2015-09-01

    In this report, we present FY2015 progress by Lawrence Berkeley National Laboratory (LBNL) related to modeling of coupled thermal-hydrological-mechanical-chemical (THMC) processes in salt and their effect on brine migration at high temperatures. This is a combined milestone report related to milestone Salt R&D Milestone “Modeling Coupled THM Processes and Brine Migration in Salt at High Temperatures” (M3FT-15LB0818012) and the Salt Field Testing Milestone (M3FT-15LB0819022) to support the overall objectives of the salt field test planning.

  3. ANODIC BEHAVIOR OF ALLOY 22 IN HIGH NITRATE BRINES AT TEMPERATURES HIGHER THAN 100C

    SciTech Connect

    G.O. LLEVBARE; J.C. ESTILL; A. YILMAZ; R.A. ETIEN; G.A. HUST M.L. STUART

    2006-04-20

    Alloy 22 (N06022) may be susceptible to crevice corrosion in chloride solutions. Nitrate acts as an inhibitor to crevice corrosion. Several papers have been published regarding the effect of nitrate on the corrosion resistance of Alloy 22 at temperatures 100 C and lower. However, very little is known about the behavior of this alloy in highly concentrated brines at temperatures above 100 C. In the current work, electrochemical tests have been carried out to explore the anodic behavior of Alloy 22 in high chloride high nitrate electrolytes at temperatures as high as 160 C at ambient atmospheres. Even though Alloy 22 may adopt corrosion potentials in the order of +0.5 V (in the saturated silver chloride scale), it does not suffer crevice corrosion if there is high nitrate in the solution. That is, the inhibitive effect of nitrate on crevice corrosion is active for temperatures higher than 100 C.

  4. A XANES study of Cu speciation in high-temperature brines using synthetic fluid inclusions

    SciTech Connect

    Berry, Andrew J.; Hack, Alistair C.; Mavrogenes, John A.; Newville, Matthew; Sutton, Stephen R.

    2010-12-03

    Cu K-edge X-ray absorption near edge structure (XANES) spectra were recorded from individual synthetic brine fluid inclusions as a function of temperature up to 500 C. The inclusions serve as sample cells for high-temperature spectroscopic studies of aqueous Cu-Cl speciation. Cu{sup +} and Cu{sup 2+} can both be identified from characteristic pre-edge features. Mixed oxidation states can be deconvoluted using linear combinations of Cu{sup +} and Cu{sup 2+} spectra. This work illustrates how complex Cu XANES spectra can be interpreted successfully. Cu{sup 2+} is the stable oxidation state in solution at room temperature and Cu{sup +} at high temperatures. The change in oxidation state with temperature was completely reversible. Cu{sup +} was found to occur exclusively as the linear species [CuCl{sub 2}]{sup -} in solutions containing KCl with Cu:Cl ratios up to 1:6. In the absence of K{sup +}, there is evidence for higher order coordination of Cu{sup +}, in particular the tetrahedral complex [CuCl{sub 4}]{sup 3-}. The importance of such complexes in natural ore-forming fluids is yet to be determined, but may explain the vapor-phase partitioning of Cu as a Cl complex from a Cl-rich brine.

  5. Modeling Coupled THMC Processes and Brine Migration in Salt at High Temperatures

    SciTech Connect

    Rutqvist, Jonny; Blanco Martin, Laura; Mukhopadhyay, Sumit; Houseworth, Jim; Birkholzer, Jens

    2014-08-14

    In this report, we present FY2014 progress by Lawrence Berkeley National Laboratory (LBNL) related to modeling of coupled thermal-hydrological-mechanical-chemical (THMC) processes in salt and their effect on brine migration at high temperatures. LBNL’s work on the modeling of coupled THMC processes in salt was initiated in FY2012, focusing on exploring and demonstrating the capabilities of an existing LBNL modeling tool (TOUGH-FLAC) for simulating temperature-driven coupled flow and geomechanical processes in salt. This work includes development related to, and implementation of, essential capabilities, as well as testing the model against relevant information and published experimental data related to the fate and transport of water. we provide more details on the FY2014 work, first presenting updated tools and improvements made to the TOUGH-FLAC simulator, and the use of this updated tool in a new model simulation of long-term THM behavior within a generic repository in a salt formation. This is followed by the description of current benchmarking and validations efforts, including the TSDE experiment. We then present the current status in the development of constitutive relationships and the dual-continuum model for brine migration. We conclude with an outlook for FY2015, which will be much focused on model validation against field experiments and on the use of the model for the design studies related to a proposed heater experiment.

  6. Anodic Behavior of Alloy 22 in High Nitrate Brines at Temperatures Higher than 100(degree)C

    SciTech Connect

    Ilevbare, G O; Etien, R A; Estill, J C; Hust, G A; Yilmaz, A; Stuart, M L; Rebak, R B

    2006-03-28

    Alloy 22 (N06022) may be susceptible to crevice corrosion in chloride solutions. Nitrate acts as an inhibitor to crevice corrosion. Several papers have been published regarding the effect of nitrate on the corrosion resistance of Alloy 22 at temperatures 100 C and lower. However, very little is known about the behavior of this alloy in highly concentrated brines at temperatures above 100 C. In the current work, electrochemical tests have been carried out to explore the anodic behavior of Alloy 22 in high chloride high nitrate electrolytes at temperatures as high as 160 C at ambient atmospheres. Even though Alloy 22 may adopt corrosion potentials in the order of +0.5 V (in the saturated silver chloride scale), it does not suffer crevice corrosion if there is high nitrate in the solution. That is, the inhibitive effect of nitrate on crevice corrosion is active for temperatures higher than 100 C.

  7. Analysis of corrosion data for carbon steels in simulated salt repository brines and acid chloride solutions at high temperatures

    SciTech Connect

    Diercks, D.R.; Hull, A.B.; Kassner, T.F.

    1988-03-01

    Carbon steel is currently the leading candidate material for fabrication of a container for isolation of high level nuclear waste in a salt repository. Since brine entrapped in the bedded salt can migrate to the container by several transport processes, corrosion is an important consideration in the long-term performance of the waste package. A detailed literature search was performed to compile relevant corrosion data for carbon steels in anoxic acid chloride solutions, and simulated salt repository brines at temperatures between approx. 20 and 400/sup 0/C. The hydrolysis of Mg/sup 2 +/ ions in simulated repository brines containing high magnesium concentrations causes acidification at temperatures above 25/sup 0/C, which, in turn, influences the protective nature of the magnetite corrosion product layer on carbon steel. The corrosion data for the steels were analyzed, and an analytical model for general corrosion was developed to calculate the amount of penetration (i.e., wall thinning) as a function of time, temperature, and the pressure of corrosion product hydrogen than can build up during exposure in a closed system (e.g., a sealed capsule). Both the temperature and pressure dependence of the corrosion rate of steels in anoxic acid chloride solutions indicate that the rate-controlling partial reaction is the cathodic reduction of water to form hydrogen. Variations in the composition and microstructure of the steels or the concentration of the ionic species in the chloride solutions (provided that they do not change the pH significantly) do not appear to strongly influence the corrosion rate.

  8. Corrosion of selected metals and a high-temperature thermoplastic in hypersaline geothermal brine. Report of investigations/1983

    SciTech Connect

    Conrad, R.K.; Carter, J.P.; Cramer, S.D.

    1983-09-01

    The Bureau of Mines conducted corrosion research to determine suitable construction materials for geothermal resource recovery plants. Weight loss, pitting and crevice corrosion, U-bend stress corrosion, and electrochemical polarization measurements were made on selected metals in brine and steam process environments produced from high-enthalpy hypersaline brine from geothermal well Magmamax No. 1 at the Salton Sea Known Geothermal Resources Area, Imperial Valley, Calif.

  9. Analysis of the corrosion of carbon steels in simulated salt repository brines and acid chloride solutions at high temperatures

    SciTech Connect

    Diercks, D.R.; Kassner, T.F.

    1988-04-01

    An analysis of literature data on the corrosion of carbon steels in anoxic brines and acid chloride solutions was performed, and the results were used to assess the expected life of high-level nuclear waste package containers in a salt repository environment. The corrosion rate of carbon steels in moderately acidic aqueous chloride environments obeys an Arrhenius dependence on temperature and a (pH{sub 2}){sup {minus}1/2} dependence on hydrogen partial pressure. The cathodic reduction of water to produce hydrogen is the rate-controlling step in the corrosion process. An expression for the corrosion rate incorporating these two dependencies was used to estimate the corrosion life of several proposed waste package configurations. 42 refs., 11 figs., 2 tabs.

  10. Materials of construction for high-salinity geothermal brines. Rept. of investigations/1992

    SciTech Connect

    Carter, J.P.; Cramer, S.D.

    1991-05-06

    The high-temperature, high-salinity geothermal brines in the Salton Sea Known Geothermal Resources Area (KGRA) are a valuable source of energy and mineral values. The brine and steam produced from them are corrosive and cause early failure of many common materials of construction. Mass-loss and electrochemical corrosion measurements were conducted on over 60 metal alloys in brine and steam environments produced from geothermal well Magmamax No. 1, located at the Salton Sea KGRA, at temperatures from 180 to 215 C, and in synthetic Magmamax brine at 105 and 232 C. General corrosion, crevice and pitting corrosion, and stress corrosion were examined along with the effects of dissolved gases. The alloys with the most acceptable corrosion performance in high-temperature, high-salinity geothermal environments were the high-chromium ferritic stainless steels, the Inconels and Hastelloys, and the titanium alloys.

  11. Stabilization of highly saline geothermal brines

    SciTech Connect

    Featherstone, J.L.; Powell, D.R.

    1981-04-01

    Severe scaling and plugging in a dual-flash test facility using hot brine from the Salton Sea geothermal resource has impeded the development of that resource. A brine treatment process proposed by Magma Power Co. appears to have eliminated these problems, making development of a 49-MW dual-flash power plant feasible. 8 refs.

  12. Impact of pressure and temperature on CO2-brine-mica contact angles and CO2-brine interfacial tension: Implications for carbon geo-sequestration.

    PubMed

    Arif, Muhammad; Al-Yaseri, Ahmed Z; Barifcani, Ahmed; Lebedev, Maxim; Iglauer, Stefan

    2016-01-15

    Precise characterization of wettability of CO2-brine-rock system and CO2-brine interfacial tension at reservoir conditions is essential as they influence capillary sealing efficiency of caprocks, which in turn, impacts the structural and residual trapping during CO2 geo-sequestration. In this context, we have experimentally measured advancing and receding contact angles for brine-CO2-mica system (surface roughness ∼12nm) at different pressures (0.1MPa, 5MPa, 7MPa, 10MPa, 15MPa, 20MPa), temperatures (308K, 323K, and 343K), and salinities (0wt%, 5wt%, 10wt%, 20wt% and 30wt% NaCl). For the same experimental matrix, CO2-brine interfacial tensions have also been measured using the pendant drop technique. The results indicate that both advancing and receding contact angles increase with pressure and salinity, but decrease with temperature. On the contrary, CO2-brine interfacial tension decrease with pressure and increase with temperature. At 20MPa and 308K, the advancing angle is measured to be ∼110°, indicating CO2-wetting. The results have been compared with various published literature data and probable factors responsible for deviations have been highlighted. Finally we demonstrate the implications of measured data by evaluating CO2 storage heights under various operating conditions. We conclude that for a given storage depth, reservoirs with lower pressures and high temperatures can store larger volumes and thus exhibit better sealing efficiency.

  13. EOS7Cm: An improved TOUGH2 module for simulating non-isothermal multiphase and multicomponent flow in CO2-H2S-CH4-brine systems with high pressure, temperature and salinity

    NASA Astrophysics Data System (ADS)

    Lei, Hongwu; Li, Jun; Li, Xiaochun; Jiang, Zhenjiao

    2016-09-01

    Understanding the non-isothermal multiphase and multicomponent flow in a CO2-H2S-CH4-brine system is of critical importance in projects such as CO2 storage in deep saline aquifers, natural gas extraction using CO2 as the displacement fluid, and heat extraction from hot dry rocks using CO2 as the working fluid. Numerical simulation is a necessary tool to evaluate the chemical evolution in these systems. However, an accurate thermodynamic model for CO2-H2S-CH4-brine systems appropriate for high pressure, temperature, and salinity is still lacking. This study establishes the mutual solubility model for CO2-H2S-CH4-brine systems based on the fugacity-activity method for phase equilibrium. The model can predict mutual solubilities for pressure up to 1000 bar for CO2 and CH4, and 200 bar for H2S, for temperature up to 200 °C, and for salinity up to 6 mol/kg water. We incorporated the new model into TOUGH2/EOS7C, forming a new improved module we call EOS7Cm. Compared to the original EOS7C, EOS7Cm considers the effects of H2S and covers a larger range of temperature and salinity. EOS7Cm is employed in five examples, including CO2 injection with and without impurities (CH4 and/or H2S) into deep aquifers, CH4 extraction from aquifers by CO2 injection, and heat extraction from hot dry rock. The results are compared to those from TOUGH2/ECO2N, EOS7C and CMG, agreement among which serves to verify EOS7Cm.

  14. Distinctive microbial community structure in highly stratified deep-sea brine water columns.

    PubMed

    Bougouffa, S; Yang, J K; Lee, O O; Wang, Y; Batang, Z; Al-Suwailem, A; Qian, P Y

    2013-06-01

    Atlantis II and Discovery are two hydrothermal and hypersaline deep-sea pools in the Red Sea rift that are characterized by strong thermohalo-stratification and temperatures steadily peaking near the bottom. We conducted comprehensive vertical profiling of the microbial populations in both pools and highlighted the influential environmental factors. Pyrosequencing of the 16S rRNA genes revealed shifts in community structures vis-à-vis depth. High diversity and low abundance were features of the deepest convective layers despite the low cell density. Surprisingly, the brine interfaces had significantly higher cell counts than the overlying deep-sea water, yet they were lowest in diversity. Vertical stratification of the bacterial populations was apparent as we moved from the Alphaproteobacteria-dominated deep sea to the Planctomycetaceae- or Deferribacteres-dominated interfaces to the Gammaproteobacteria-dominated brine layers. Archaeal marine group I was dominant in the deep-sea water and interfaces, while several euryarchaeotic groups increased in the brine. Across sites, microbial phylotypes and abundances varied substantially in the brine interface of Discovery compared with Atlantis II, despite the near-identical populations in the overlying deep-sea waters. The lowest convective layers harbored interestingly similar microbial communities, even though temperature and heavy metal concentrations were very different. Multivariate analysis indicated that temperature and salinity were the major influences shaping the communities. The harsh conditions and the low-abundance phylotypes could explain the observed correlation in the brine pools. PMID:23542623

  15. Distinctive Microbial Community Structure in Highly Stratified Deep-Sea Brine Water Columns

    PubMed Central

    Bougouffa, S.; Yang, J. K.; Lee, O. O.; Wang, Y.; Batang, Z.; Al-Suwailem, A.

    2013-01-01

    Atlantis II and Discovery are two hydrothermal and hypersaline deep-sea pools in the Red Sea rift that are characterized by strong thermohalo-stratification and temperatures steadily peaking near the bottom. We conducted comprehensive vertical profiling of the microbial populations in both pools and highlighted the influential environmental factors. Pyrosequencing of the 16S rRNA genes revealed shifts in community structures vis-à-vis depth. High diversity and low abundance were features of the deepest convective layers despite the low cell density. Surprisingly, the brine interfaces had significantly higher cell counts than the overlying deep-sea water, yet they were lowest in diversity. Vertical stratification of the bacterial populations was apparent as we moved from the Alphaproteobacteria-dominated deep sea to the Planctomycetaceae- or Deferribacteres-dominated interfaces to the Gammaproteobacteria-dominated brine layers. Archaeal marine group I was dominant in the deep-sea water and interfaces, while several euryarchaeotic groups increased in the brine. Across sites, microbial phylotypes and abundances varied substantially in the brine interface of Discovery compared with Atlantis II, despite the near-identical populations in the overlying deep-sea waters. The lowest convective layers harbored interestingly similar microbial communities, even though temperature and heavy metal concentrations were very different. Multivariate analysis indicated that temperature and salinity were the major influences shaping the communities. The harsh conditions and the low-abundance phylotypes could explain the observed correlation in the brine pools. PMID:23542623

  16. Mineralogical changes of a well cement in various H2S-CO2(-brine) fluids at high pressure and temperature.

    PubMed

    Jacquemet, Nicolas; Pironon, Jacques; Saint-Marc, Jérémie

    2008-01-01

    The reactivity of a crushed well cement in contact with (1) a brine with dissolved H2S-CO2; (2) a dry H2S-CO2 supercritical phase; (3) a two-phase fluid associating a brine with dissolved H2S-CO2 and a H2S-CO2 supercritical phase was investigated in batch experiments at 500 bar and 120, 200 degrees C. All of the experiments showed that following 15-60 days cement carbonation occurred. The H2S reactivity with cement is limited since it only transformed the ferrites (minor phases) by sulfidation. It appeared that the primary parameter controlling the degree of carbonation (i.e., the rate of calcium carbonates precipitation and CSH (Calcium Silicate Hydrates) decalcification) is the physical state of the fluid phase contacting the minerals. The carbonation degree is complete when the minerals contact at least the dry H2S-CO2 supercritical phase and partial when they contactthe brine with dissolved H2S-CO2. Aragonite (calcium carbonate polymorph) precipitated specifically within the dry H2S-CO2 supercritical phase. CSH cristallinity is improved by partial carbonation while CSH are amorphized by complete carbonation. However, the features evidenced in this study cannot be directly related to effective features of cement as a monolith. Further studies involving cement as a monolith are necessary to ascertain textural, petrophysical, and mechanical evolution of cement.

  17. Durability of concrete materials in high-magnesium brine

    SciTech Connect

    Wakeley, L.D.; Poole, T.S.; Burkes, J.P.

    1994-03-01

    Cement pastes and mortars representing 11 combinations of candidate concrete materials were cast in the laboratory and monitored for susceptibility to chemical deterioration in high-magnesium brine. Mixtures were selected to include materials included in the current leading candidate concrete for seals at the Waste Isolation Pilot Plant (WIPP). Some materials were included in the experimental matrix to answer questions that had arisen during study of the concrete used for construction of the liner of the WIPP waste-handling shaft. Mixture combinations compared Class C and Class F fly ashes, presence or absence of an expansive component, and presence or absence of salt as a mixture component. Experimental conditions exposed the pastes and mortars to extreme conditions, those being very high levels of Mg ion and an effectively unlimited supply of brine. All pastes and mortars showed deterioration with brine exposure. In general, mortars deteriorated more extensively than the corresponding pastes. Two-inch cube specimens of mortar were not uniformly deteriorated, but showed obvious zoning even after a year in the brine, with a relatively unreacted zone remaining at the center of each cube. Loss of calcium from the calcium hydroxide of paste/aggregate interfaces caused measurable strength loss in the reacted zone comprising the outer portion of every mortar specimen. The current candidate mass concrete for WIPP seals includes salt as an initial component, and has a relatively closed initial microstructure. Both of these features contribute to its suitability for use in large placements within the Salado Formation.

  18. Self-oscillations in large storages of highly mineralized brines

    NASA Astrophysics Data System (ADS)

    Lyubimova, Tatyana; Lepikhin, Anatoly; Tsiberkin, Kirill; Parshakova, Yanina

    2014-05-01

    One of the stages of the production process at large enrichment plants is settling of aqueous solutions in large technological storages. The present work is devoted to the modeling of hydrodynamic regimes of large storage of highly mineralized brines. The density of brines in these objects depends not only on the content of dissolved macrocomponents, but also on the concentration of fine particulate matter. This leads to the need to consider the dynamics of the suspended sediment under significant density stratification, which greatly complicates the problem. Because of that it is important to develop hydrodynamical models of these objects. A peculiarity of these systems is the possibility of self-oscillatory regimes the mechanism of which is as follows. In warm sunny days, with high solar insolation, the heating of the sediments and bottom water takes place. The bottom water warming and the decrease of its density give rise to flow. The slurry particles composing the sediments are involved in the flow. The heated particles entrained by the flow transfer the heat to the surrounding liquid and increase the absorption of the solar radiation in the volume, which leads to equalization of temperature and convective flow damping. After the particle settling on the bottom the process is repeated. We study the stability of equilibrium of the horizontal liquid layer containing heavy insoluble particles in the presence of evaporation from the free surface and solar radiation absorption by insoluble particles. The time-dependent solution of heat transfer problem is obtained and used for estimate of time of instability onset. It is found that for the layer of saturated brines of potassium chloride of the thickness about 10 m the time for instability onset is about one hour. By using analytical estimates based on the empirical model of turbulence by Prandtl we confirmed the time for the onset of instability and obtained the estimates for the period of self

  19. Modeling of highly brines transport in large water bodies

    NASA Astrophysics Data System (ADS)

    Lyubimova, T. P.; Lepikhin, A. P.; Parshakova, Y. N.; Tiunov, A. A.

    2010-05-01

    The paper deals with the numerical modeling of a dilution and transport of highly brines in large water bodies taking into account the density stratification effects. This problem has an exceptional importance for the guarantee of ecological security of the Kama Reservoir in the conditions of extending exploitation of Verhnekamsk deposit of potassium and magnesium salts - one of the largest in the world. The output of million of tones of the potassium fertilizer is accompanied by the producing of the same quantity of highly brines demanding utilization. With the existing technologies the desalination of such quantity of brines is extremely energy-capacious and almost inapplicable. That is why main way for the brine utilization is the release into the surface water bodies or underground water-bearing horizons. Since the uncertainty level in the parameter setting for underground water-bearing horizons is higher than that for the surface water bodies, under the same or close conditions the release into the surface water bodies is considerably less dangerous. The main water body able to assimilate such huge amount of the removed brines is the upper part of the Kama Reservoir located within the Solikamsk-Berezniki industrial centre. The wastewater arriving from this centre make a decisive contribution to the formation of hydrochemical regime of Kama river. We suggested two-dimensional imitational hydrodynamical model allowing to determine the possible pollution zones depending on the flow rate and concentration of pollutant, flow rate and water level in the Kama river and wind characteristics in the zone of pollutant discharge. This model allows not only to calculate the distribution of pollution zones for various pollutant sources but also to estimate the consequences of emergencies. The Kama river near the Solikamsk-Berezniki industrial centre has complex morphometry. For the complete and efficient accounting for the morphometry peculiarities the non-linear orthogonal

  20. TOUGHREACT Testing in High Ionic Strength Brine Sandstone Systems

    SciTech Connect

    Xu, Tianfu

    2008-09-01

    Deep saline formations and oil and gas reservoirs often contain concentrated brine solutions of ionic strength greater than 1 (I > 1 M). Geochemical modeling, involving high ionic strength brines, is a challenge. In the original TOUGHREACT code (Xu et al., 2004; Xu et al., 2006), activity coefficients of charged aqueous species are computed using an extended Debye-Huckel (DH) equation and parameters derived by Helgeson et al. (1981). The DH model can deal with ionic strengths from dilute to moderately saline water (up to 6 molal for an NaCl-dominant solution). The equations implemented for the DH model are presented in Appendix A. During the course of the Yucca Mountain project, a Pitzer ion-interaction model was implemented into TOUGHREACT. This allows the application of this simulator to problems involving much more concentrated aqueous solutions, such as those involving geochemical processes in and around high-level nuclear waste repositories where fluid evaporation and/or boiling is expected to occur (Zhang et al., 2007). The Pitzer ion-interaction model, which we refer to as the Pitzer virial approach, and associated ion-interaction parameters have been applied successfully to study non-ideal concentrated aqueous solutions. The formulation of the Pitzer model is presented in Appendix B; detailed information can be founded in Zhang et al. (2007). For CO{sub 2} geological sequestration, the Pitzer ion-interaction model for highly concentrated brines was incorporated into TOUGHREACT/ECO2N, then was tested and compared with a previously implemented extended Debye-Hueckel (DH) ion activity model. The comparison was made through a batch geochemical system using a Gulf Coast sandstone saline formation.

  1. Field tests to determine scaling tendency of some moderate-temperature geothermal brines

    SciTech Connect

    Robertus, R.J.; Sullivan, R.G.; Shannon, D.W.

    1986-09-01

    Several field tests were completed to determine the scaling tendency of moderate-temperature geothermal brines. Data were taken on the Heber as well as the East Mesa Known-Geothermal-Resources-Areas (KGRA's). The test results most directly benefit the Heber Geothermal Binary Demonstration Plant, but some have been generalized to be useful for other moderate-temperature (302 to 460/sup 0/F (150 to 239/sup 0/C)) geothermal reservoirs also. Field experiments determined conditions under which calcite, silica, and metal sulfides are likely to form. The calcite tests determined pressures which must be maintained to prevent gas-breakout and ensuing calcite deposition. Required pressures varied from one reservoir to the next and were strong functions of non-condensable gas content. The brine cooling tests tried to quantify the amount of silica which would drop out of the Heber brine by incrementally cooling it below a design set point of 150/sup 0/F (66/sup 0/C). The conclusion was that no detectable increase in silica occurred in times relevant to plant operations when the brine was cooled to 120/sup 0/F (49/sup 0/C). Although the cooling tests showed no detectable increase in silica formation, other materials did form in small amounts. The list includes magnetite (Fe/sub 3/O/sub 4/), calcite (CaCO/sub 3/), and mixtures of lead, zinc, and arsenic sulfides. Even for the lowest outlet temperature (120/sup 0/F) the particulate loading increased only about 50% over inlet conditions. Thus, for the Heber brines, the majority of material entering an injection well comes in the form of sand from the production wells. This same conclusion was supported by earlier work on the East Mesa KGRA.

  2. Stability of brines on Mars

    NASA Technical Reports Server (NTRS)

    Brass, G. W.

    1980-01-01

    The detection of high chlorine and sulfate abundances and duricrusts on Mars strongly suggests the occasional presence of brines on the Martian surface. Ternary phase diagrams for the likely chloride and sulfate brines indicate that the minimum temperature at which a brine can be stable is near 210 K with a water concentration of approximately 70 wt % and a high concentration of calcium chloride. The dominance of sulfate over chlorine in the Martian regolith suggests precipitation of salts at temperatures higher than the minimum.

  3. On laboratory simulation and the temperature dependence of the evaporation rate of brine on Mars

    NASA Astrophysics Data System (ADS)

    Sears, Derek W. G.; Chittenden, Julie D.

    2005-12-01

    We have determined the evaporation rate of brine under simulated martian conditions at temperatures from 0°C to -26.0°C as part of our efforts to better understand the stability of water on Mars. Correcting for the effect of water build-up in the atmosphere and the lower gravity on Mars relative to Earth we observed a factor of almost 30 decrease in evaporation, from 0.88 mm/h at ~0°C to 0.04 mm/h at -25.0°C. The results are in excellent agreement with the predictions of Ingersoll's (1970) theoretical treatment, lending support to the theory and our procedures. Thus brine formation will increase the stability of water on Mars not only by extending the liquid temperature range, but also by considerably decreasing the evaporation rate.

  4. Treatment of high salinity brines by direct contact membrane distillation: Effect of membrane characteristics and salinity.

    PubMed

    Li, Jianfeng; Guan, Yunshan; Cheng, Fangqin; Liu, Yu

    2015-12-01

    Direct contact membrane distillation (DCMD) is one of the attractive technologies for high salinity brine treatment. In this study, four polytetrafluoroethylene (PTFE) membranes were examined in treating highly concentrated salt solutions. Results showed that non-supported membranes generally have a higher overall mass transfer coefficient but porosity seems to be the most important parameter controlling membrane flux and thermal efficiency. Supported membranes with large thickness had relatively higher thermal efficiency than small thickness. This can be attributed to their reduced heat loss through heat condition. In addition, KCl, NaCl and MgCl2 solutions showed distinct trends over flux decline at high salt concentrations (⩾2.0M). The difference in flux was largely due to the discrepancy in water activities of these solutions (KCl>NaCl>MgCl2). However, the effect of viscosity on permeate flux could not be neglected for MgCl2 at high salt concentrations as the suddenly increased viscosity could lead to serious temperature polarization. This study indicates that membrane distillation is a promising technology for high salinity brine treatment. PMID:25563165

  5. Treatment of high salinity brines by direct contact membrane distillation: Effect of membrane characteristics and salinity.

    PubMed

    Li, Jianfeng; Guan, Yunshan; Cheng, Fangqin; Liu, Yu

    2015-12-01

    Direct contact membrane distillation (DCMD) is one of the attractive technologies for high salinity brine treatment. In this study, four polytetrafluoroethylene (PTFE) membranes were examined in treating highly concentrated salt solutions. Results showed that non-supported membranes generally have a higher overall mass transfer coefficient but porosity seems to be the most important parameter controlling membrane flux and thermal efficiency. Supported membranes with large thickness had relatively higher thermal efficiency than small thickness. This can be attributed to their reduced heat loss through heat condition. In addition, KCl, NaCl and MgCl2 solutions showed distinct trends over flux decline at high salt concentrations (⩾2.0M). The difference in flux was largely due to the discrepancy in water activities of these solutions (KCl>NaCl>MgCl2). However, the effect of viscosity on permeate flux could not be neglected for MgCl2 at high salt concentrations as the suddenly increased viscosity could lead to serious temperature polarization. This study indicates that membrane distillation is a promising technology for high salinity brine treatment.

  6. Formation damage tests of high-density brine completion fluids

    SciTech Connect

    Morgenthaler, L.N.

    1986-11-01

    Laboratory core flow tests were conducted to assess the formation damage potential of brines with densities between 13.4 and 19.2 lbm/gal (1606 and 2301 kg/m/sup 3/). Unfavorable fluid/rock interactions are not evident. Recovery of oil permeability is slow but complete, in agreement with established displacement theories. Observed damage effects are the result of the instability of the brine or incompatibility with water in the cores. The effectiveness of ZnBr/sub 2/ in preventing impairment suggests acid-soluble impairing materials.

  7. Liquid-vapor partitioning of NaCl(aq) from concentrated brines at temperatures to 350{degrees}C

    SciTech Connect

    Simonson, J.M.; Palmer, Donald A.; Carter, R.W.

    1994-01-20

    Compositions of coexisting liquid and vapor phases have been determined at temperatures from 250 to 350°C for brines containing NaCl and either HCI or NaOH by direct sampling of both phases from a static phase-equilibration apparatus. In these experiments, NaCl concentrations in the liquid phase ranged to 6.5 mol-kg{sup -1}, with corresponding vapor-phase NaCl concentrations varying strongly with temperature and brine composition. Acid or base was added to the brines to suppress unknown contributions of NaCl(aq) hydrolysis products to the observed volatilities. Thermodynamic partitioning constants for NaCl have been determined from the observed compositions of the coexisting phases combined with the known activity coefficients of NaCl(aq) in the liquid phase. An apparent dependence of the values of these partitioning constants on brine concentration is explained by considering the effect of decreasing pressure on the density of the vapor phase. Concentrations of HCI and NaCl in steam produced from various natural brines may be calculated as hnctions of temperature and brine composition based on these new results coupled with our previous determinations of the partitioning constants for HCl(aq). Application of these results to The Geysers will be discussed in terms of the composition of postulated brines which could be in equilibrium with observed steam compositions at various temperatures.

  8. Purification of High Salinity Brine by Multi-Stage Ion Concentration Polarization Desalination.

    PubMed

    Kim, Bumjoo; Kwak, Rhokyun; Kwon, Hyukjin J; Pham, Van Sang; Kim, Minseok; Al-Anzi, Bader; Lim, Geunbae; Han, Jongyoon

    2016-08-22

    There is an increasing need for the desalination of high concentration brine (>TDS 35,000 ppm) efficiently and economically, either for the treatment of produced water from shale gas/oil development, or minimizing the environmental impact of brine from existing desalination plants. Yet, reverse osmosis (RO), which is the most widely used for desalination currently, is not practical for brine desalination. This paper demonstrates technical and economic feasibility of ICP (Ion Concentration Polarization) electrical desalination for the high saline water treatment, by adopting multi-stage operation with better energy efficiency. Optimized multi-staging configurations, dependent on the brine salinity values, can be designed based on experimental and numerical analysis. Such an optimization aims at achieving not just the energy efficiency but also (membrane) area efficiency, lowering the true cost of brine treatment. ICP electrical desalination is shown here to treat brine salinity up to 100,000 ppm of Total Dissolved Solids (TDS) with flexible salt rejection rate up to 70% which is promising in a various application treating brine waste. We also demonstrate that ICP desalination has advantage of removing both salts and diverse suspended solids simultaneously, and less susceptibility to membrane fouling/scaling, which is a significant challenge in the membrane processes.

  9. Purification of High Salinity Brine by Multi-Stage Ion Concentration Polarization Desalination

    NASA Astrophysics Data System (ADS)

    Kim, Bumjoo; Kwak, Rhokyun; Kwon, Hyukjin J.; Pham, Van Sang; Kim, Minseok; Al-Anzi, Bader; Lim, Geunbae; Han, Jongyoon

    2016-08-01

    There is an increasing need for the desalination of high concentration brine (>TDS 35,000 ppm) efficiently and economically, either for the treatment of produced water from shale gas/oil development, or minimizing the environmental impact of brine from existing desalination plants. Yet, reverse osmosis (RO), which is the most widely used for desalination currently, is not practical for brine desalination. This paper demonstrates technical and economic feasibility of ICP (Ion Concentration Polarization) electrical desalination for the high saline water treatment, by adopting multi-stage operation with better energy efficiency. Optimized multi-staging configurations, dependent on the brine salinity values, can be designed based on experimental and numerical analysis. Such an optimization aims at achieving not just the energy efficiency but also (membrane) area efficiency, lowering the true cost of brine treatment. ICP electrical desalination is shown here to treat brine salinity up to 100,000 ppm of Total Dissolved Solids (TDS) with flexible salt rejection rate up to 70% which is promising in a various application treating brine waste. We also demonstrate that ICP desalination has advantage of removing both salts and diverse suspended solids simultaneously, and less susceptibility to membrane fouling/scaling, which is a significant challenge in the membrane processes.

  10. Purification of High Salinity Brine by Multi-Stage Ion Concentration Polarization Desalination

    PubMed Central

    Kim, Bumjoo; Kwak, Rhokyun; Kwon, Hyukjin J.; Pham, Van Sang; Kim, Minseok; Al-Anzi, Bader; Lim, Geunbae; Han, Jongyoon

    2016-01-01

    There is an increasing need for the desalination of high concentration brine (>TDS 35,000 ppm) efficiently and economically, either for the treatment of produced water from shale gas/oil development, or minimizing the environmental impact of brine from existing desalination plants. Yet, reverse osmosis (RO), which is the most widely used for desalination currently, is not practical for brine desalination. This paper demonstrates technical and economic feasibility of ICP (Ion Concentration Polarization) electrical desalination for the high saline water treatment, by adopting multi-stage operation with better energy efficiency. Optimized multi-staging configurations, dependent on the brine salinity values, can be designed based on experimental and numerical analysis. Such an optimization aims at achieving not just the energy efficiency but also (membrane) area efficiency, lowering the true cost of brine treatment. ICP electrical desalination is shown here to treat brine salinity up to 100,000 ppm of Total Dissolved Solids (TDS) with flexible salt rejection rate up to 70% which is promising in a various application treating brine waste. We also demonstrate that ICP desalination has advantage of removing both salts and diverse suspended solids simultaneously, and less susceptibility to membrane fouling/scaling, which is a significant challenge in the membrane processes. PMID:27545955

  11. Purification of High Salinity Brine by Multi-Stage Ion Concentration Polarization Desalination.

    PubMed

    Kim, Bumjoo; Kwak, Rhokyun; Kwon, Hyukjin J; Pham, Van Sang; Kim, Minseok; Al-Anzi, Bader; Lim, Geunbae; Han, Jongyoon

    2016-01-01

    There is an increasing need for the desalination of high concentration brine (>TDS 35,000 ppm) efficiently and economically, either for the treatment of produced water from shale gas/oil development, or minimizing the environmental impact of brine from existing desalination plants. Yet, reverse osmosis (RO), which is the most widely used for desalination currently, is not practical for brine desalination. This paper demonstrates technical and economic feasibility of ICP (Ion Concentration Polarization) electrical desalination for the high saline water treatment, by adopting multi-stage operation with better energy efficiency. Optimized multi-staging configurations, dependent on the brine salinity values, can be designed based on experimental and numerical analysis. Such an optimization aims at achieving not just the energy efficiency but also (membrane) area efficiency, lowering the true cost of brine treatment. ICP electrical desalination is shown here to treat brine salinity up to 100,000 ppm of Total Dissolved Solids (TDS) with flexible salt rejection rate up to 70% which is promising in a various application treating brine waste. We also demonstrate that ICP desalination has advantage of removing both salts and diverse suspended solids simultaneously, and less susceptibility to membrane fouling/scaling, which is a significant challenge in the membrane processes. PMID:27545955

  12. Solubilities of corundum, wollastonite and quartz in H 2O-NaCl solutions at 800 °C and 10 kbar: Interaction of simple minerals with brines at high pressure and temperature

    NASA Astrophysics Data System (ADS)

    Newton, Robert C.; Manning, Craig E.

    2006-11-01

    molar ratios of reactant H 2O to NaCl of 6:1 and 2:1, respectively. Our results imply that quite simple mechanisms may exist in the dissolution of common rock-forming minerals in saline fluids at high P and T and allow assessment of the interaction of simple, congruently soluble rock-forming minerals with brines associated with deep-crustal metamorphism.

  13. Partitioning of Organic Contaminants and Tracer Compounds in a CO2-Brine System at High Salinities

    NASA Astrophysics Data System (ADS)

    Thomas, B.; Kharaka, Y. K.; Rosenbauer, R. J.; Janesko, D.; Trutna, J.

    2011-12-01

    Nonionic chemical species including gases and organic compounds partition between the fluid CO2 phase and the aqueous phase in geologic carbon sequestration systems. The injection and migration of CO2 in geologic carbon sequestration systems covers a wide range of pressure and temperature, so it is important to understand the partitioning of these compounds at various P-T conditions and salinities. Geochemical data is particularly lacking for the partitioning of organic contaminant compounds and tracer compounds between highly saline brines and CO2. Most groundwater is relatively low in organic contaminants; however, groundwater associated with hydrocarbon migration pathways, enhanced oil recovery (EOR), and hydrocarbon storage or extraction can contain high concentrations of known organic contaminants. CO2 injection in these systems may therefore be more likely to result in partitioning of contaminants into the CO2 phase that could, upon migration, represent an important risk to groundwater resources. We present the experimental apparatus and determination of partition coefficients between brine and CO2 for a suite of compounds including benzene, toluene, ethylbenzene, xylene (BTEX), and low molecular weight polynuclear aromatic hydrocarbons (PAHs). In addition, partition coefficients are determined for the important gas phase tracer compounds: SF6 and Krypton covering a P-T envelope consistent with CO2 injection and plume migration to the near surface.

  14. REE Sorption Study for Media #1 and Media #2 in Brine #1 and #2 at different Liquid to Solid Ratio's at Ambient Temperature

    SciTech Connect

    Gary Garland

    2015-03-27

    This data set shows the different loading capacities of Media #1 and Media #2 in a high and low salt content brine matrix at different liquid to solid ratio's. These data sets are shaker bath tests on media #1 and media #2 in brine's #1 and #2 at 500mL-.5g(1000-1 ratio), 150mL-.75g(200-1 ratio), and 150mL-2.5g(60-1 ratio) at ambient temperature.

  15. The effect of aging, temperature and brine composition on the mechanical strength of chalk

    NASA Astrophysics Data System (ADS)

    Korsnes, Reidar Inge; Nermoen, Anders; Stødle, Trond; Vika Storm, Eirik; Vadla Madland, Merete

    2014-05-01

    Chalk strength has been of great focus for several research communities since the 1980s when the Ekofisk subsidence problem was discovered. Sea water injection was initiated in 1987 to improve the oil production and to re-pressurize the reservoirs to halt the subsidence. The oil production was improved significantly, but the reservoir compaction in the water saturated regions continued, in contrast to the regions with no water breakthrough. This observation indicates a water weakening effect of the chalk. Extensive studies have been performed during the last decades to enlighten how the brine chemistry alters the rock mechanical properties. These studies have shown that the elastic bulk modulus, yield strength, creep and the deformation rate at constant stress conditions depend on the pore fluid composition. In general, the injected brine is in non-equilibrium with the rock surface inducing alteration of the rock mineralogy. In this study we examined two aspects of the mechanical strength, namely the bulk modulus and the onset of yield during hydrostatic stress loading with 0.7 MPa pore pressure. The test program consisted of aged and un-aged cores, ambient and 130°C test temperature, and four brine compositions: MgCl2, NaCl, Na2SO4, and synthetic sea water (SSW) at ion strengths of 0.657 M. The aging was performed by submerging saturated cores in a closed container with the respective test brine for three weeks at 130°C. Un-aged cores were saturated the same day as they were tested. For each brine composition we present four test setups; (a) aged and tested at 130°C, (b) aged and tested at ambient temperature, (c) un-aged and tested at 130°C, and (d) un-aged and tested at ambient conditions. The main results from our study are: 1. By using NaCl and MgCl2 as saturating brines, neither the test temperature nor the aging procedure affected the yield stress and bulk modulus significantly. 2. Using Na2SO4, the yield point and bulk moduli were reduced if the core

  16. Diversity and characterization of mercury-resistant bacteria in snow, freshwater and sea-ice brine from the High Arctic.

    PubMed

    Møller, Annette K; Barkay, Tamar; Abu Al-Soud, Waleed; Sørensen, Søren J; Skov, Henrik; Kroer, Niels

    2011-03-01

    It is well-established that atmospheric deposition transports mercury from lower latitudes to the Arctic. The role of bacteria in the dynamics of the deposited mercury, however, is unknown. We characterized mercury-resistant bacteria from High Arctic snow, freshwater and sea-ice brine. Bacterial densities were 9.4 × 10(5), 5 × 10(5) and 0.9-3.1 × 10(3) cells mL(-1) in freshwater, brine and snow, respectively. Highest cultivability was observed in snow (11.9%), followed by freshwater (0.3%) and brine (0.03%). In snow, the mercury-resistant bacteria accounted for up to 31% of the culturable bacteria, but <2% in freshwater and brine. The resistant bacteria belonged to the Alpha-, Beta- and Gammaproteobacteria, Firmicutes, Actinobacteria, and Bacteriodetes. Resistance levels of most isolates were not temperature dependent. Of the resistant isolates, 25% reduced Hg(II) to Hg(0). No relation between resistance level, ability to reduce Hg(II) and phylogenetic group was observed. An estimation of the potential bacterial reduction of Hg(II) in snow suggested that it was important in the deeper snow layers where light attenuation inhibited photoreduction. Thus, by reducing Hg(II) to Hg(0), mercury-resistant bacteria may limit the supply of substrate for methylation processes and, hence, contribute to lowering the risk that methylmercury is being incorporated into the Arctic food chains. PMID:21166687

  17. Liquid-vapor partitioning of NaCl(aq) from concentrated brines at temperatures to 350{degrees}C

    SciTech Connect

    Simonson, J.M.; Palmer, D.A.; Carter, R.W.

    1994-03-01

    Compositions of coexisting liquid and vapor phases have been determined at temperatures from 250 to 350{degree}C for brines containing NaCl and either HCl or NaOH by direct sampling of both phases from a static phase-equilibration apparatus. Thermodynamic partitioning constants for NaCl have been determined from the observed compositions of the coexisting phases combined with the known activity coefficients of NaCl(aq) in the liquid phase. An apparent dependence of the values of these partitioning constants on brine concentration is explained by considering the effect of decreasing pressure on the density of the vapor phase. Concentrations of HCl and NaCl in steam produced from various natural brines may be calculated as functions of temperature and brine composition based on these new results coupled with our previous determinations of the partitioning constants for HCl(aq). Application of these results to The Geysers will be discussed in terms of the composition of postulated brines which could be in equilibrium with observed steam compositions at various temperatures.

  18. Expected brine movement at potential nuclear waste repository salt sites

    SciTech Connect

    McCauley, V.S.; Raines, G.E.

    1987-08-01

    The BRINEMIG brine migration code predicts rates and quantities of brine migration to a waste package emplaced in a high-level nuclear waste repository in salt. The BRINEMIG code is an explicit time-marching finite-difference code that solves a mass balance equation and uses the Jenks equation to predict velocities of brine migration. Predictions were made for the seven potentially acceptable salt sites under consideration as locations for the first US high-level nuclear waste repository. Predicted total quantities of accumulated brine were on the order of 1 m/sup 3/ brine per waste package or less. Less brine accumulation is expected at domal salt sites because of the lower initial moisture contents relative to bedded salt sites. Less total accumulation of brine is predicted for spent fuel than for commercial high-level waste because of the lower temperatures generated by spent fuel. 11 refs., 36 figs., 29 tabs.

  19. Isotopic constraints on the origin of the Atlantis II, Suakin and Valdivia brines, Red Sea

    USGS Publications Warehouse

    Zierenberg, R.A.; Shanks, Wayne C.

    1986-01-01

    The origin of three Red Sea submarine brine pools was investigated by analysis of the S and O isotope ratios of dissolved sulfate and Sr isotope ratios of dissolved Sr in the brines. Sulfur and O isotope ratios of sulfate and Sr isotope ratios of evaporitic source rocks for the brines were measured for comparison. The S, O and Sr isotope ratios of evaporites recovered from DSDP site 227 are consistent with an upper Miocene evaporites age. The Valdivia Deep brine formed by karstic dissolution of Miocene evaporites by overlying seawater and shows no signs of hydrothermal input. The Suakin Deep brines are derived from, or have isotopically exchanged with Miocene or older evaporites. There has been only minor dilution of the brine by overlying seawater. Strontium isotope ratios of Suakin brine may indicate addition of a minor (15%) amount of volcanic Sr to the brine, but there is no evidence of high temperature brine-rock interaction. The sulfate in the Atlantis II brine was apparently derived from seawater. The O isotope ratio of sulfate in the present Atlantis II brine could reflect isotopic exchange between seawater sulfate and the brine at approximately 255??C. Approximately 30% of the Sr in the Atlantis II brine is derived from the underlying basalt, probably by hydrothermal leaching. Atlantis II brine is the only known example from the Red Sea which has a significant high-temperature hydrothermal history. ?? 1986.

  20. Ultra-high chlorine in submarine Kilauea glasses: evidence for direct assimilation of brine by magma

    USGS Publications Warehouse

    Coombs, Michelle L.; Sisson, Thomas W.; Kimura, Jun-Ichi

    2004-01-01

    Basaltic glass grains from the submarine south flank of Kı̄lauea, Hawai′i, have Cl concentrations of 0.01–1.68 wt%, the latter being the highest Cl content yet recorded for a Hawaiian glass. The high-Cl glass grains are products of brine assimilation by tholeiite magma. The glasses are grains in a sandstone clast from bedded breccias draping the southwestern margin of Kı̄lauea’s submarine midslope bench. The clast contains two distinct suites of glass grains: abundant degassed tholeiites, perhaps derived from subaerial lavas of Mauna Loa that shattered upon ocean entry, and a smaller population of Kea-type tholeiite (n=17 analyzed) that erupted subaqueously, based on elevated S (780–1050 ppm), H2O (0.42–1.27 wt%), and CO2 (<30–120 ppm), probably early in Kı̄lauea’s shield-building stage. Ten grains in this group have Cl>1000 ppm, six >5000 ppm, and two grains have >10 000 ppm dissolved Cl. Abundances of H2O, Na2O, K2O, and several trace elements increase regularly with Cl concentration, and we estimate that Cl enrichment was due to up to 13 wt% addition of a brine consisting of 78% H2O (wt), 13% Cl, 4.4% Na, 2.6% K, 2.6% Ca, 620 ppm Ba, 360 ppm Sr, 65 ppm Rb, and 7 ppm Pb. The large amounts of brine addition argue against bulk assimilation of low-porosity brine-bearing rock. The brine’s composition is appropriate for a seawater-derived hydrothermal fluid that reacted with basaltic wall rocks at T>100°C, losing Mg and S and gaining K, Ca, Rb, Ba, Sr, and Pb, followed by phase separation near 500°C and ∼50 MPa (5 km below sea level at hydrostatic pressure). Brine was assimilated at or near the depth it formed, as estimated on petrologic grounds, but under lithostatic conditions. The highest extents of assimilation either forced volatile saturation of the magma or enriched already coexisting magmatic vapor in H2O. Possible mechanisms for assimilation are: (1) forcible injection of brine into magma during bursting of overpressured pockets

  1. Iron oxide nanoparticles grafted with sulfonated copolymers are stable in concentrated brine at elevated temperatures and weakly adsorb on silica.

    PubMed

    Bagaria, Hitesh G; Xue, Zheng; Neilson, Bethany M; Worthen, Andrew J; Yoon, Ki Youl; Nayak, Susheela; Cheng, Victoria; Lee, Jae Ho; Bielawski, Christopher W; Johnston, Keith P

    2013-04-24

    Magnetic nanoparticles that can be transported in subsurface reservoirs at high salinities and temperatures are expected to have a major impact on enhanced oil recovery, carbon dioxide sequestration, and electromagnetic imaging. Herein we report a rare example of steric stabilization of iron oxide (IO) nanoparticles (NPs) grafted with poly(2-acrylamido-2-methylpropanesulfonate-co-acrylic acid) (poly(AMPS-co-AA)) that not only display colloidal stability in standard American Petroleum Institute (API) brine (8% NaCl + 2% CaCl2 by weight) at 90 °C for 1 month but also resist undesirable adsorption on silica surfaces (0.4% monolayer NPs). Because the AMPS groups interacted weakly with Ca(2+), they were sufficiently well solvated to provide steric stabilization. The PAA groups, in contrast, enabled covalent grafting of the poly(AMPS-co-AA) chains to amine-functionalized IO NPs via formation of amide bonds and prevented polymer desorption even after a 40,000-fold dilution. The aforementioned methodology may be readily adapted to stabilize a variety of other functional inorganic and organic NPs at high salinities and temperatures. PMID:23527819

  2. Ikaite solubility in seawater-derived brines at 1 atm and sub-zero temperatures to 265 K

    NASA Astrophysics Data System (ADS)

    Papadimitriou, Stathys; Kennedy, Hilary; Kennedy, Paul; Thomas, David N.

    2013-05-01

    The concentration-based (stoichiometric) equilibrium solubility product of ikaite (CaCO3·6H2O) in seawater and cryogenic seawater-derived brines was determined at 1 atm total pressure over the temperature range from -1.1 to -7.5 °C and the salinity range from 34 to 124 in temperature-salinity pairs representative of sea ice brines. The solubility measurements were obtained in solutions that were undersaturated and supersaturated with respect to ikaite by equilibration with CO2/N2 gas mixtures of known pCO2 (20-400 μatm). The solutions were then equilibrated with synthetic ikaite (seed) for up to 3 months in a closed system. Arrival of the solid-solution system at a long-term chemical equilibrium was indicated by attainment of constant chemical solution composition with respect to total dissolved calcium, total dissolved inorganic carbon, and total alkalinity. Using these measurements, the stoichiometric equilibrium solubility product of ikaite (Ksp,ikaite∗=[Ca][CO32-], in molkgsolution-2) was determined, with the carbonate ion concentration computed from the measured total alkalinity and total dissolved inorganic carbon concentrations. The computed carbonate ion concentration and, by extension, the Ksp,ikaite∗ are both contingent on solving the system of equations that describe the parameters of the CO2 system in seawater by extrapolation to the experimental salinity and temperature conditions. The results show that the pKsp,ikaite∗=-logKsp,ikaite∗ in seawater of salinity 34 at -1.1 °C was 5.362 ± 0.004 and that the pKsp,ikaite∗ in sea ice at the freezing point of brines of salinity greater than 34 can be described as a function of temperature (T, in K) by the equation, pKsp,ikaite∗=-15489.09608+623443.70216T-1+2355.14596lnT, in the temperature range of 265.15 K < T < 271.15 K (-8 °C < t < -2 °C). Brines of low pCO2 (20 μatm) yielded a much slower (>1 month) approach to chemical equilibrium when incubated without seeding ikaite crystals. Simple

  3. Volatility of HCl and the thermodynamics of brines during brine dryout

    SciTech Connect

    Simonson, J.M.; Palmer, D.A.

    1997-04-01

    Laboratory measurements of liquid-vapor partitioning (volatility) of chlorides from brines to steam can be used to indicate the potential for corrosion problems in geothermal systems. Measurements of volatilities of solutes in chloride brines have established a possible mechanism for the production of high-chloride steam from slightly acidic high temperature brines. Questions concerning the fate of NaCl in the steam production process have been addressed through extensive measurements of its volatility from brines ranging in concentration from dilute solutions to halite saturation. Recent measurements of chloride partitioning to steam over brines in contact with Geysers rock samples are consistent with our concept of the process for production of high-chloride steam.

  4. The effect of brine pH, concentration and temperature on zeta potential measured in natural sandstones

    NASA Astrophysics Data System (ADS)

    Jackson, M.; Vinogradov, J.

    2015-12-01

    The zeta potential is a measure of the electrical potential of the mineral surfaces in water-saturated rocks. In many subsurface settings the rocks are at elevated temperature, yet the temperature dependence of the zeta potential remains poorly understood. There are few previous experimental studies and these report inconsistent and contradictory behaviour; some studies have found that the zeta potential increases in magnitude with increasing temperature while others have found that it decreases in magnitude. Moreover, few studies have investigated salt concentrations relevant to natural systems; most used de-ionised water or NaCl/KCl electrolytes at low ionic strength (10-3M). Natural groundwater is typically more saline than this. We report measurements of the zeta potential of natural sandstones saturated with NaCl brines of varying ionic strength at temperatures up to 150°C. We find that the zeta potential is always negative, but decreases in magnitude with increasing temperature at in 0.01M NaCl brine (comparable to potable water) and is independent of temperature in 0.5M brine (comparable to seawater). In unbuffered experiments, the pH also decreases with increasing temperature at low ionic strength, but remains constant at higher ionic strength. The temperature dependence of the zeta potential can be explained by the temperature dependence of the pH. Our findings are consistent with published models of the zeta potential, so long as the temperature dependence of the pH at low ionic strength is accounted for. Moreover, they explain the hitherto contradictory results reported in previous studies that used low ionic strength electrolytes. In unbuffered experiments, the pH decreases with increasing temperature and the zeta potential decreases in magnitude. In experiments with fixed pH, the zeta potential increases in magnitude with increasing temperature. The results have broad application to deep sandstone reservoirs and hydrothermal fields.

  5. Utilizing rare earth elements as tracers in high TDS reservoir brines in CCS applications

    DOE PAGESBeta

    McLing, Travis; Smith, William; Smith, Robert

    2014-12-31

    conditions. Our research has shown that the REE signature imparted to the formation fluid by the introduction of CO₂ to the formation, can be measured and tracked as part of an MMV program. Additionally, this REE fingerprint may serve as an ideal tracer for fluid migration, both within the CCS target formation, and should formation fluids migrate into overlying aquifers. However application of REE and other trace elements to CCS system is complicated by the high salt content of the brines contained within the target formations. In the United States by regulation, in order for a geologic reservoir to be considered suitable for carbon storage, it must contain formation brine with total dissolved solids (TDS) > 10,000 ppm, and in most cases formation brines have TDS well in excess of that threshold. The high salinity of these brines creates analytical problems for elemental analysis, including element interference with trace metals in Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) (i.e. element mass overlap due to oxide or plasma phenomenon). Additionally, instruments like the ICP-MS that are sensitive enough to measure trace elements down to the parts per trillion level are quickly oversaturated when water TDS exceeds much more than 1,000 ppm. Normally this problem is dealt with through dilution of the sample, bringing the water chemistry into the instruments working range. However, dilution is not an option when analyzing these formation brines for trace metals, because trace elements, specifically the REE, which occur in aqueous solutions at the parts per trillion levels. Any dilution of the sample would make REE detection impossible. Therefore, the ability to use trace metals as in situ natural tracers in high TDS brines environments requires the development of methods for pre-concentrating trace elements, while reducing the salinity and associated elemental interference such that the brines can be routinely analyzed by standard ICP-MS methods. As part of the Big

  6. Utilizing rare earth elements as tracers in high TDS reservoir brines in CCS applications

    SciTech Connect

    McLing, Travis; Smith, William; Smith, Robert

    2014-12-31

    reservoir conditions. Our research has shown that the REE signature imparted to the formation fluid by the introduction of CO₂ to the formation, can be measured and tracked as part of an MMV program. Additionally, this REE fingerprint may serve as an ideal tracer for fluid migration, both within the CCS target formation, and should formation fluids migrate into overlying aquifers. However application of REE and other trace elements to CCS system is complicated by the high salt content of the brines contained within the target formations. In the United States by regulation, in order for a geologic reservoir to be considered suitable for carbon storage, it must contain formation brine with total dissolved solids (TDS) > 10,000 ppm, and in most cases formation brines have TDS well in excess of that threshold. The high salinity of these brines creates analytical problems for elemental analysis, including element interference with trace metals in Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) (i.e. element mass overlap due to oxide or plasma phenomenon). Additionally, instruments like the ICP-MS that are sensitive enough to measure trace elements down to the parts per trillion level are quickly oversaturated when water TDS exceeds much more than 1,000 ppm. Normally this problem is dealt with through dilution of the sample, bringing the water chemistry into the instruments working range. However, dilution is not an option when analyzing these formation brines for trace metals, because trace elements, specifically the REE, which occur in aqueous solutions at the parts per trillion levels. Any dilution of the sample would make REE detection impossible. Therefore, the ability to use trace metals as in situ natural tracers in high TDS brines environments requires the development of methods for pre-concentrating trace elements, while reducing the salinity and associated elemental interference such that the brines can be routinely analyzed by standard ICP-MS methods. As

  7. Development of a Rapid, Nondestructive Method to Measure Aqueous Carbonate in High Salinity Brines Using Raman Spectroscopy

    NASA Astrophysics Data System (ADS)

    McGraw, L.; Phillips-Lander, C. M.; Elwood Madden, A. S.; Parnell, S.; Elwood Madden, M.

    2015-12-01

    Traditional methods of quantitative analysis are often ill-suited to determining the bulk chemistry of high salinity brines due to their corrosive and clogging properties. Such methods are also often difficult to apply remotely in planetary environments. However, Raman spectroscopy can be used remotely without physical contact with the fluid and is not affected by many ionic brines. Developing methods to study aqueous carbonates is vital to future study of brines on Mars and other planetary bodies, as they can reveal important information about modern and ancient near-surface aqueous processes. Both sodium carbonate standards and unknown samples from carbonate mineral dissolution experiments in high salinity brines were analyzed using a 532 nm laser coupled to an inVia Renishaw spectrometer to collect carbonate spectra from near-saturated sodium chloride and sodium sulfate brines. A calibration curve was determined by collecting spectra from solutions of known carbonate concentrations mixed with a pH 13 buffer and a near-saturated NaCl or Na2SO4 brine matrix. The spectra were processed and curve fitted to determine the height ratio of the carbonate peak at 1066 cm-1 to the 1640 cm-1 water peak. The calibration curve determined using the standards was then applied to the experimental data after accounting for dilutions. Concentrations determined based on Raman spectra were compared against traditional acid titration measurements. We found that the two techniques vary by less than one order of magnitude. Further work is ongoing to verify the method and apply similar techniques to measure aqueous carbonate concentrations in other high salinity brines.Traditional methods of quantitative analysis are often ill-suited to determining the bulk chemistry of high salinity brines due to their corrosive and clogging properties. Such methods are also often difficult to apply remotely in planetary environments. However, Raman spectroscopy can be used remotely without physical

  8. Wettability measurement under high P-T conditions using X-ray imaging with application to the brine-supercritical CO2 system

    NASA Astrophysics Data System (ADS)

    Chaudhary, Kuldeep; Guiltinan, Eric J.; Cardenas, M. Bayani; Maisano, Jessica A.; Ketcham, Richard A.; Bennett, Philip C.

    2015-09-01

    We present a new method for measuring wettability or contact angle of minerals at reservoir pressure-temperature conditions using high-resolution X-ray computed tomography (HRXCT) and radiography. In this method, a capillary or a narrow slot is constructed from a mineral or a rock sample of interest wherein two fluids are allowed to form an interface that is imaged using X-rays. After some validation measurements at room pressure-temperature conditions, we illustrate this method by measuring the contact angle of CO2-brine on quartz, muscovite, shale, borosilicate glass, polytetrafluoroethylene (PTFE or Teflon), and polyether ether ketone (PEEK) surfaces at 60-71°C and 13.8-22.8 MPa. At reservoir conditions, PTFE and PEEK surfaces were found to be CO2-wet with contact angles of 140° and 127°, respectively. Quartz and muscovite were found to be water-wet with contact angles of 26° and 58°, respectively, under similar conditions. Borosilicate glass-air-brine at room conditions showed strong water-wet characteristics with a contact angle of 9°, whereas borosilicate glass-CO2-brine at 13.8 MPa and 60°C showed a decrease in its water-wetness with contact angle of 54°. This method provides a new application for X-ray imaging and an alternative to other methods.

  9. Radioactive waste isolation in salt: geochemistry of brine in rock salt in temperature gradients and gamma-radiation fields - a selective annotated bibliography

    SciTech Connect

    Hull, A.B.; Williams, L.B.

    1985-07-01

    Evaluation of the extensive research concerning brine geochemistry and transport is critically important to successful exploitation of a salt formation for isolating high-level radioactive waste. This annotated bibliography has been compiled from documents considered to provide classic background material on the interactions between brine and rock salt, as well as the most important results from more recent research. Each summary elucidates the information or data most pertinent to situations encountered in siting, constructing, and operating a mined repository in salt for high-level radioactive waste. The research topics covered include the basic geology, depositional environment, mineralogy, and structure of evaporite and domal salts, as well as fluid inclusions, brine chemistry, thermal and gamma-radiation effects, radionuclide migration, and thermodynamic properties of salts and brines. 4 figs., 6 tabs.

  10. Evaluation of materials for systems using cooled, treated geothermal or high-saline brines

    SciTech Connect

    Suciu, D.F.; Wikoff, P.M.

    1982-09-01

    Lack of adequate quantities of clean surface water for use in wet (evaporative) cooling systems indicates the use of high-salinity waste waters, or cooled geothermal brines, for makeup purposes. High-chloride, aerated water represents an extremely corrosive environment. In order to determine metals suitable for use in such an environment, metal coupons were exposed to aerated, treated geothermal brine salted to a chloride concentration of 10,000 and 50,000 ppM (mg/L) for periods of up to 30 days. The exposed coupons were evaluated to determine the general, pitting, and crevice corrosion characteristics of the metals. The metals exhibiting corrosion resistance at 50,000 ppM chloride were then evaluated at 100,000 and 200,000 ppM chloride. Since these were screening tests to select materials for components to be used in a cooling system, with primary emphasis on condenser tubing, several materials were exposed for 4 to 10 months in pilot cooling tower test units with heat transfer for further corrosion evaluation. The results of the screening tests indicate that ferritic stainless steels (29-4-2 and SEA-CURE) exhibit excellent corrosion resistance at all levels of chloride concentration. Copper-nickel alloys (70/30 and Monel 400) exhibited excellent corrosion resistance in the high-saline water. The 70/30 copper-nickel alloy, which showed excellent resistance to general corrosion, exhibited mild pitting in the 30-day tests. This pitting was not apparent, however, after 6 months of exposure in the pilot cooling tower tests. The nickel-base alloys exhibited excellent corrosion resistance, but their high cost prevents their use unless no other material is found feasible. Other materials tested, although unsuitable for condenser tubing material, would be suitable as tube sheet material.

  11. Brine migration in salt in a thermal gradient

    NASA Astrophysics Data System (ADS)

    Kang, M.; Lerche, M.; Lesher, C. E.

    2015-12-01

    Salt deposits have long been considered viable repositories for long-term storage of high-level nuclear waste. However, brine trapped in salt tends to migrate up thermal gradients, such as can develop around radioactive waste storage containers, potentially promoting corrosion of containment structures. Brine inclusions move up the temperature gradient through the three main steps: 1) the dissolution of salt at the hot side of the inclusion caused by increased salt solubility, 2) ordinary and thermal diffusion of dissolved salt ions within the inclusion, and 3) precipitation of salt at the cold side of the inclusion due to local supersaturation. This process of brine transport through salt under a thermal gradient is generally referred to as thermal migration. Here we investigated thermal migration of brine inclusion in salts for a wide range of mean temperatures (~ 50 °C to ~200 °C) and temperature gradients (~ 10 °C/cm to ~57 °C/cm). With time brine inclusions moving towards the heat source become elongated parallel to the thermal gradient. We quantified the rate of brine migration as a function of mean temperature and thermal gradient using time-lapse optical microscope. X -ray and neutron tomography were used to visualize and quantify 3D spatial distribution of brine inclusion in a salt crystal at different stages of thermal migration. Migration velocities are shown to increase with temperature, temperature gradient and size of inclusion. We find an abrupt increase in migration velocity at certain time steps of thermal migration. Migration velocities of brine inclusions ranged from 0.1 m/year to 30.7 m/year. Empirical equations at different velocity regions for brine inclusions were obtained by fitting exponential equations to the experimental data with high coefficient of determination values (R2> 0.94).The experimental results are in good agreement with the theoretical migration rates obtained using a previous analytical model.

  12. Experimental investigation of CO2-brine-rock interactions at elevated temperature and pressure: Implications for CO2 sequestration in deep-saline aquifers

    USGS Publications Warehouse

    Rosenbauer, R.J.; Koksalan, T.; Palandri, J.L.

    2005-01-01

    Deep-saline aquifers are potential repositories for excess CO2, currently being emitted to the atmosphere from anthropogenic activities, but the reactivity of supercritical CO2 with host aquifer fluids and formation minerals needs to be understood. Experiments reacting supercritical CO2 with natural and synthetic brines in the presence and absence of limestone and plagioclase-rich arkosic sandstone showed that the reaction of CO2-saturated brine with limestone results in compositional, mineralogical, and porosity changes in the aquifer fluid and rock that are dependent on initial brine composition, especially dissolved calcium and sulfate. Experiments reacting CO2-saturated, low-sulfate brine with limestone dissolved 10% of the original calcite and increased rock porosity by 2.6%. Experiments reacting high-sulfate brine with limestone, both in the presence and absence of supercritical CO2, were characterized by the precipitation of anhydrite, dolomitization of the limestone, and a final decrease in porosity of 4.5%. However, based on favorable initial porosity changes of about 15% due to the dissolution of calcite, the combination of CO2 co-injection with other mitigation strategies might help alleviate some of the well-bore scale and formation-plugging problems near the injection zone of a brine disposal well in Paradox Valley, Colorado, as well as provide a repository for CO2. Experiments showed that the solubility of CO2 is enhanced in brine in the presence of limestone by 9% at 25 ??C and 6% at 120 ??C and 200 bar relative to the brine itself. The solubility of CO2 is enhanced also in brine in the presence of arkosic sandstone by 5% at 120 ??C and 300 bar. The storage of CO 2 in limestone aquifers is limited to only ionic and hydraulic trapping. However, brine reacted with supercritical CO2 and arkose yielded fixation and sequestration of CO2 in carbonate mineral phases. Brine desiccation was observed in all experiments containing a discrete CO2 phase

  13. Materials of construction for Salton Sea geothermal brines

    SciTech Connect

    Carter, J.P. ); Cramer, S.D. )

    1989-01-01

    The high-temperature, high-salinity geothermal brines of the Salton Sea KGRA are a valuable source of energy and minerals. However, these brines are also very corrosive and cause early failure of many common materials of construction. Ferritic steels containing less than 18 wt pct chromium and austenitic steels perform poorly in these environments. This paper reports that the most acceptable materials of construction are the high-chromium ferritic stainless steels, nickel alloys, and titanium alloys.

  14. A Comparison of the Corrosion Resistance of Iron-Based Amorphous Metals and Austenitic Alloys in Synthetic Brines at Elevated Temperature

    SciTech Connect

    Farmer, J C

    2008-11-25

    Several hard, corrosion-resistant and neutron-absorbing iron-based amorphous alloys have now been developed that can be applied as thermal spray coatings. These new alloys include relatively high concentrations of Cr, Mo, and W for enhanced corrosion resistance, and substantial B to enable both glass formation and neutron absorption. The corrosion resistances of these novel alloys have been compared to that of several austenitic alloys in a broad range of synthetic brines, with and without nitrate inhibitor, at elevated temperature. Linear polarization and electrochemical impedance spectroscopy have been used for in situ measurement of corrosion rates for prolonged periods of time, while scanning electron microscopy (SEM) and energy dispersive analysis of X-rays (EDAX) have been used for ex situ characterization of samples at the end of tests. The application of these new coatings for the protection of spent nuclear fuel storage systems, equipment in nuclear service, steel-reinforced concrete will be discussed.

  15. Calcium chloride brines: The vital component in the hydrothermal brine-hydrothermal ore deposit-evaporite-basinal brine cycle in continental rift basins

    SciTech Connect

    Hardie, L. . Dept. of Earth and Planetary Science)

    1992-01-01

    Nonmarine evaporites are forming today in chloride-rich saline lakes in a number of arid continental rift and strike-slip basins that are characterized by upwelling of subsurface CaCl[sub 2]-bearing brines driven by forced convection of cool basinal brines or by free convection of hydrothermal brines which reach the surface as brine springs. The compositions of these upwelling brines are distinctively different from that of seawater or typical continental waters due primarily to their high proportion of Ca and low proportion of SO[sub 4]. The most viable explanation for the CaCl[sub 2] composition of these upwelling brines is the interaction between hot convecting groundwaters and bedrock at or above zeolite facies temperatures, as for example occurs in the modern Salton Sea basin. Such upwelling CaCl[sub 2] brines in extensional fault basins can explain the puzzling chemical composition of MgSO[sub 4]-poor potash evaporites, the least understood of all ancient salt deposits. In this regard it is suggested that the following cyclic succession of processes occurs in active continental rift basins during a magmatically-driven thermal event: (1) hydrothermal convection of the ambient porewaters in the rift sediments, (2) dissolution of buried evaporites and hydrothermal metamorphism of the rift sediments, (3) hydrothermal ore deposition in fault-related fractures and within the rift sediments, (4) upwelling brine springs add CaCl[sub 2] and KCl components to the surface lake waters, which on evaporation produce MgSO[sub 4]-poor potash evaporites, (5) decay of the thermal event leads to cool down of the hot brines, which now migrate gravitationally to the deeper parts of the basin to become static Na-Ca-Cl basinal brines.

  16. High temperature furnace

    DOEpatents

    Borkowski, Casimer J.

    1976-08-03

    A high temperature furnace for use above 2000.degree.C is provided that features fast initial heating and low power consumption at the operating temperature. The cathode is initially heated by joule heating followed by electron emission heating at the operating temperature. The cathode is designed for routine large temperature excursions without being subjected to high thermal stresses. A further characteristic of the device is the elimination of any ceramic components from the high temperature zone of the furnace.

  17. Corrosion behavior of CRA`s in high density packer fluids at high temperature

    SciTech Connect

    Scoppio, L.; Barteri, M.; Cheldi, T.; Ke, M.; Massi, S.

    1999-11-01

    Results from an experimental investigation carried out in high density brine packer fluids are presented. Different variables were examined, namely temperature, time of exposure, chemical inhibition and brine composition and density. Tests to compare the performance of different classes of stainless steels were carried out by autoclave exposure under different deaerated brines solutions: NaCl/NaBr, CaCl{sub 2}/CaBr{sub 2} and CaBr{sub 3}/ZnBr{sub 2}, CaCl{sub 2}, CaCl{sub 2}/CaBr{sub 2}/ZnBr{sub 2}. General corrosion, localized corrosion (pitting and crevice), galvanic corrosion and resistance to environmental cracking were evaluated both in absence of corrosion inhibitor and with the addition of two different commercial inhibitors. Duplex steels were very resistant to the localized corrosion, although pitting and crevice were present in some combination of brine and temperature. The martensitic steel was very sensitive to the general and the localized corrosion. Brine CaCl{sub 2}/CaBr{sub 2} {rho} = 1.75 g/cm{sup 3}, showed at 200 C, a pitting on 13%Cr lower than expected. This is probably due to the general corrosion which show a mechanism competitive with localized corrosion. As a result, pitting corrosion is a matter of big concern when applications in heavy brine are considered. In fact only the most alloyed materials at temperature below 200 C can be considered as immune. As a consequence, the effect of commercially available corrosion inhibitors is sometime lower than expected and there is a need of further improvements of corrosion inhibitors for the application to the CRA`S (Corrosion Resistant Alloys) in brine environments at 200 C.

  18. Brines formed by multi-salt deliquescence

    SciTech Connect

    Carroll, S; Rard, J; Alai, M; Staggs, K

    2005-11-04

    The FY05 Waste Package Environment testing program at Lawrence Livermore National Laboratory focused on determining the temperature, relative humidity, and solution compositions of brines formed due to the deliquescence of NaCl-KNO{sub 3}-NaNO{sub 3} and NaCl-KNO{sub 3}-NaNO{sub 3}-Ca(NO{sub 3}){sub 2} salt mixtures. Understanding the physical and chemical behavior of these brines is important because they define conditions under which brines may react with waste canister surfaces. Boiling point experiments show that NaCl-KNO{sub 3}-NaNO{sub 3} and NaCl-KNO{sub 3}-NaNO{sub 3}-Ca(NO{sub 3}){sub 2} salt mixtures form brines that transform to hydrous melts that do not truly 'dry out' until temperatures exceed 300 and 400 C, respectively. Thus a conducting solution is present for these salt assemblages over the thermal history of the repository. The corresponding brines form at lower relative humidity at higher temperatures. The NaCl-KNO{sub 3}-NaNO{sub 3} salt mixture has a mutual deliquescence relative humidity (MDRH) of 25.9% at 120 C and 10.8% at 180 C. Similarly, the KNO{sub 3}-NaNO{sub 3} salt mixture has MDRH of 26.4% at 120 C and 20.0% at 150 C. The KNO{sub 3}-NaNO{sub 3} salt mixture salts also absorb some water (but do not appear to deliquesce) at 180 C and thus may also contribute to the transfer of electrons at interface between dust and the waste package surface. There is no experimental evidence to suggest that these brines will degas and form less deliquescent salt assemblages. Ammonium present in atmospheric and tunnel dust (as the chloride, nitrate, or sulfate) will readily decompose in the initial heating phase of the repository, and will affect subsequent behavior of the remaining salt mixture only through the removal of a stoichiometric equivalent of one or more anions. Although K-Na-NO{sub 3}-Cl brines form at high temperature and low relative humidity, these brines are dominated by nitrate, which is known to inhibit corrosion at lower temperature

  19. Cytogenetic damage in shallot ( Allium cepa) root meristems induced by oil industry "high-density brines".

    PubMed

    Vidaković-Cifrek, Z; Pavlica, M; Regula, I; Papes, D

    2002-10-01

    Saturated water solutions of calcium chloride, calcium bromide (densities 1.30 kg x dm(-3) and 1.61 kg x dm(-3), respectively) and their 1:1 mixture have been commonly used as oil industry "high-density brines." In our experiment they were added to tap water in amounts appropriate to achieve concentrations of 0.025, 0.05, 0.075, and 0.1 mol x dm(-3) to study their cytotoxic effect on the root tip cells of shallot ( Allium cepa L. var. ascalonicum). All tested solutions in concentrations of 0.075 and 0.1 mol x dm(-3) caused significant inhibition of shallot root growth. CaBr (2) showed this effect in concentration 0.05 mol x dm(-3). The investigated solutions in all concentrations applied decreased mitotic activity in root tip cells. The most of mitotic abnormalities were the consequence of spindle failure and chromosome stickiness. Furthermore, the cell microtubules were investigated by indirect immunofluorescence to confirm that most abnormalities observed were the consequence of spindle failure. The present study, as well as previously done Lemna tests and Chlorella tests showed that investigated samples have certain effects on plants, so constant control of their presence in the environment is needed.

  20. Changes in microbial diversity of brined green asparagus upon treatment with high hydrostatic pressure.

    PubMed

    Toledo Del Árbol, Julia; Pérez Pulido, Rubén; La Storia, Antonietta; Grande Burgos, Maria José; Lucas, Rosario; Ercolini, Danilo; Gálvez, Antonio

    2016-01-01

    The application of high hydrostatic pressure (HHP, 600MPa, 8 min) on brined green asparagus and the changes in bacterial diversity after treatments and during storage at 4 °C (30 days) or 22 °C (10 days) were studied. HHP treatments reduced viable cell counts by 3.6 log cycles. The residual surviving population did not increase during storage at 4 °C. However, bacterial counts significantly increased at 22 °C by day 3, leading to rapid spoilage. The microbiota of green asparagus was composed mainly by Proteobacteria (mainly Pantoea and Pseudomonas), followed by Firmicutes (mainly Lactococcus and Enterococcus) and to a less extent Bacteroidetes and Actinobacteria. During chill storage of untreated asparagus, the relative abundance of Proteobacteria as well as Enterococcus and Lactococcus decreased while Lactobacillus increased. During storage of untreated asparagus at 22 °C, the abundance of Bacteroidetes decreased while Proteobacteria increased during late storage. The HHP treatment determined a reduction of the Proteobacteria both early after treatment and during chill storage. In the HHP treated samples stored at 22 °C, the relative abundance of Pseudomonas rapidly decreased at day 1, with an increase of Bacteroidetes. This was followed by a marked increase in Enterobacteriaceae (Escherichia) simultaneously with increase in viable counts and spoilage. Results from the study indicate that the effect of HHP treatments on the viability ofmicrobial populations in foods also has an impact on the dynamics of microbial populations during the storage of the treated foods. PMID:26372734

  1. Changes in microbial diversity of brined green asparagus upon treatment with high hydrostatic pressure.

    PubMed

    Toledo Del Árbol, Julia; Pérez Pulido, Rubén; La Storia, Antonietta; Grande Burgos, Maria José; Lucas, Rosario; Ercolini, Danilo; Gálvez, Antonio

    2016-01-01

    The application of high hydrostatic pressure (HHP, 600MPa, 8 min) on brined green asparagus and the changes in bacterial diversity after treatments and during storage at 4 °C (30 days) or 22 °C (10 days) were studied. HHP treatments reduced viable cell counts by 3.6 log cycles. The residual surviving population did not increase during storage at 4 °C. However, bacterial counts significantly increased at 22 °C by day 3, leading to rapid spoilage. The microbiota of green asparagus was composed mainly by Proteobacteria (mainly Pantoea and Pseudomonas), followed by Firmicutes (mainly Lactococcus and Enterococcus) and to a less extent Bacteroidetes and Actinobacteria. During chill storage of untreated asparagus, the relative abundance of Proteobacteria as well as Enterococcus and Lactococcus decreased while Lactobacillus increased. During storage of untreated asparagus at 22 °C, the abundance of Bacteroidetes decreased while Proteobacteria increased during late storage. The HHP treatment determined a reduction of the Proteobacteria both early after treatment and during chill storage. In the HHP treated samples stored at 22 °C, the relative abundance of Pseudomonas rapidly decreased at day 1, with an increase of Bacteroidetes. This was followed by a marked increase in Enterobacteriaceae (Escherichia) simultaneously with increase in viable counts and spoilage. Results from the study indicate that the effect of HHP treatments on the viability ofmicrobial populations in foods also has an impact on the dynamics of microbial populations during the storage of the treated foods.

  2. Methodology Measuring Rare Earth Elements in High TDS Reservoir Brines Application as Natural Tracers in CCUS Studies

    NASA Astrophysics Data System (ADS)

    Smith, W.; Mcling, T. L.; Smith, R. W.; Neupane, H.

    2013-12-01

    In recent years rare earth elements (REE) have been demonstrated to be useful natural tracers for geochemical processes in aqueous environments. The application of REE's to carbon dioxide utilization and storage (CCUS) could provide researchers with a sensitive, inexpensive tool for tracking the movement of CO2 and displaced formation brines. By definition, geologic reservoirs that have been deemed suitable for carbon capture and storage contain formation brine with total dissolved solids (TDS) greater than 10,000 ppm and often these formation brines exceed 75,000 ppm TDS. This high TDS water makes it very difficult to measure REE, which typically occur at part per trillion concentrations. Critical to the use of REE for CCUS studies is the development of a procedure, which allows for the pre-concentration of REE's across a wide range of water quality. Additionally, due to the large number of samples that will need analysis, any developed procedure must be inexpensive, reproducible, and quick to implement. As part of the Big Sky Carbon Sequestration Project the INL's Center for Advance Energy Studies is developing REE pre-concentration procedures based on methods reported in the literature. While there are many REE pre-concentration procedures in the literature, our tests have shown these methods have difficulty at TDS greater than seawater (roughly 35,000 ppm TDS). Therefore, the ability to quantitatively measure REE's in formation brines with very high TDS has required the modification of an already developed procedure. After careful consideration and testing we selected methods modified after those described by Kingston et al., 1978 and Strachan et al., 1989 utilizing chelating media for very high TDS waters and ion-exchange media as detailed by Crock et al., 1984; Robinson et al., 1985; and Stetzenbach et al., 1994 for low TDS (<10,000 ppm TDS) waters. These modified procedures have been successfully tested in our laboratory and have proven effective in greatly

  3. Ionic Effects on Supercritical CO2-Brine Interfacial Tensions: Molecular Dynamics Simulations and a Universal Correlation with Ionic Strength, Temperature, and Pressure.

    PubMed

    Zhao, Lingling; Ji, Jiayuan; Tao, Lu; Lin, Shangchao

    2016-09-13

    For geological CO2 storage in deep saline aquifers, the interfacial tension (IFT) between supercritical CO2 and brine is critical for the storage security and design of the storage capacitance. However, currently, no predictive model exists to determine the IFT of supercritical CO2 against complex electrolyte solutions involving various mixed salt species at different concentrations and compositions. In this paper, we use molecular dynamics (MD) simulations to investigate the effect of salt ions on the incremental IFT at the supercritical CO2-brine interface with respect to that at the reference supercritical CO2-water interface. Supercritical CO2-NaCl solution, CO2-CaCl2 solution and CO2-(NaCl+CaCl2) mixed solution systems are simulated at 343 K and 20 MPa under different salinities and salt compositions. We find that the valence of the cations is the primary contributor to the variation in IFT, while the Lennard-Jones potentials for the cations pose a smaller impact on the IFT. Interestingly, the incremental IFT exhibits a general linear correlation with the ionic strength in the above three electrolyte systems, and the slopes are almost identical and independent of the solution types. Based on this finding, a universal predictive formula for IFTs of CO2-complex electrolyte solution systems is established, as a function of ionic strength, temperature, and pressure. The predicted IFTs using the established formula agree perfectly (with a high statistical confidence level of ∼96%) with a wide range of experimental data for CO2 interfacing with different electrolyte solutions, such as those involving MgCl2 and Na2SO4. This work provides an efficient and accurate route to directly predict IFTs in supercritical CO2-complex electrolyte solution systems for practical engineering applications, such as geological CO2 sequestration in deep saline aquifers and other interfacial systems involving complex electrolyte solutions.

  4. Ionic Effects on Supercritical CO2-Brine Interfacial Tensions: Molecular Dynamics Simulations and a Universal Correlation with Ionic Strength, Temperature, and Pressure.

    PubMed

    Zhao, Lingling; Ji, Jiayuan; Tao, Lu; Lin, Shangchao

    2016-09-13

    For geological CO2 storage in deep saline aquifers, the interfacial tension (IFT) between supercritical CO2 and brine is critical for the storage security and design of the storage capacitance. However, currently, no predictive model exists to determine the IFT of supercritical CO2 against complex electrolyte solutions involving various mixed salt species at different concentrations and compositions. In this paper, we use molecular dynamics (MD) simulations to investigate the effect of salt ions on the incremental IFT at the supercritical CO2-brine interface with respect to that at the reference supercritical CO2-water interface. Supercritical CO2-NaCl solution, CO2-CaCl2 solution and CO2-(NaCl+CaCl2) mixed solution systems are simulated at 343 K and 20 MPa under different salinities and salt compositions. We find that the valence of the cations is the primary contributor to the variation in IFT, while the Lennard-Jones potentials for the cations pose a smaller impact on the IFT. Interestingly, the incremental IFT exhibits a general linear correlation with the ionic strength in the above three electrolyte systems, and the slopes are almost identical and independent of the solution types. Based on this finding, a universal predictive formula for IFTs of CO2-complex electrolyte solution systems is established, as a function of ionic strength, temperature, and pressure. The predicted IFTs using the established formula agree perfectly (with a high statistical confidence level of ∼96%) with a wide range of experimental data for CO2 interfacing with different electrolyte solutions, such as those involving MgCl2 and Na2SO4. This work provides an efficient and accurate route to directly predict IFTs in supercritical CO2-complex electrolyte solution systems for practical engineering applications, such as geological CO2 sequestration in deep saline aquifers and other interfacial systems involving complex electrolyte solutions. PMID:27564433

  5. High temperature reactors

    NASA Astrophysics Data System (ADS)

    Dulera, I. V.; Sinha, R. K.

    2008-12-01

    With the advent of high temperature reactors, nuclear energy, in addition to producing electricity, has shown enormous potential for the production of alternate transport energy carrier such as hydrogen. High efficiency hydrogen production processes need process heat at temperatures around 1173-1223 K. Bhabha Atomic Research Centre (BARC), is currently developing concepts of high temperature reactors capable of supplying process heat around 1273 K. These reactors would provide energy to facilitate combined production of hydrogen, electricity, and drinking water. Compact high temperature reactor is being developed as a technology demonstrator for associated technologies. Design has been also initiated for a 600 MWth innovative high temperature reactor. High temperature reactor development programme has opened new avenues for research in areas like advanced nuclear fuels, high temperature and corrosion resistant materials and protective coatings, heavy liquid metal coolant technologies, etc. The paper highlights design of these reactors and their material related requirements.

  6. High temperature sensor

    DOEpatents

    Tokarz, Richard D.

    1982-01-01

    A high temperature sensor includes a pair of electrical conductors separated by a mass of electrical insulating material. The insulating material has a measurable resistivity within the sensor that changes in relation to the temperature of the insulating material within a high temperature range (1,000 to 2,000 K.). When required, the sensor can be encased within a ceramic protective coating.

  7. High-Temperature Superconductivity

    NASA Astrophysics Data System (ADS)

    Tanaka, Shoji

    2006-12-01

    A general review on high-temperature superconductivity was made. After prehistoric view and the process of discovery were stated, the special features of high-temperature superconductors were explained from the materials side and the physical properties side. The present status on applications of high-temperature superconductors were explained on superconducting tapes, electric power cables, magnets for maglev trains, electric motors, superconducting quantum interference device (SQUID) and single flux quantum (SFQ) devices and circuits.

  8. High temperature refrigerator

    DOEpatents

    Steyert, Jr., William A.

    1978-01-01

    A high temperature magnetic refrigerator which uses a Stirling-like cycle in which rotating magnetic working material is heated in zero field and adiabatically magnetized, cooled in high field, then adiabatically demagnetized. During this cycle said working material is in heat exchange with a pumped fluid which absorbs heat from a low temperature heat source and deposits heat in a high temperature reservoir. The magnetic refrigeration cycle operates at an efficiency 70% of Carnot.

  9. High temperature measuring device

    DOEpatents

    Tokarz, Richard D.

    1983-01-01

    A temperature measuring device for very high design temperatures (to 2,000.degree. C.). The device comprises a homogenous base structure preferably in the form of a sphere or cylinder. The base structure contains a large number of individual walled cells. The base structure has a decreasing coefficient of elasticity within the temperature range being monitored. A predetermined quantity of inert gas is confined within each cell. The cells are dimensionally stable at the normal working temperature of the device. Increases in gaseous pressure within the cells will permanently deform the cell walls at temperatures within the high temperature range to be measured. Such deformation can be correlated to temperature by calibrating similarly constructed devices under known time and temperature conditions.

  10. Silica in alkaline brines

    USGS Publications Warehouse

    Jones, B.F.; Rettig, S.L.; Eugster, H.P.

    1967-01-01

    Analysis of sodium carbonate-bicarbonate brines from closed basins in volcanic terranes of Oregon and Kenya reveals silica contents of up to 2700 parts per million at pH's higher than 10. These high concentrations of SiO 2 can be attributed to reaction of waters with silicates, and subsequent evaporative concentration accompanied by a rise in pH. Supersaturation with respect to amorphous silica may occur and persist for brines that are out of contact with silicate muds and undersaturated with respect to trona; correlation of SiO2 with concentration of Na and total CO2 support this interpretation. Addition of moredilute waters to alkaline brines may lower the pH and cause inorganic precipitation of substantial amounts of silica.

  11. Experimental evidence for supercooled brines, viscous liquids, and low temperature perchlorate glasses on Mars

    NASA Astrophysics Data System (ADS)

    Toner, J.; Catling, D. C.; Light, B.

    2013-12-01

    The presence of liquid water on the cold and dry surface of Mars is possible where concentrated salt solutions lower the freezing point of water. The eutectic temperature is the maximum equilibrium freezing point depression possible for a given salt solution, which ranges from near 0°C for carbonates and sulfates, to as low as -75°C for perchlorates. Although eutectic temperatures suggest a lower temperature limit for liquid water on Mars, salt solutions will typically supercool below their eutectic before crystallization occurs. We report on results investigating the magnitude of supercooling and its variation with salt composition and concentration for pure salt solutions and saturated soil solutions of MgSO4, MgCl2, NaCl, NaClO4, Mg(ClO4)2, and Ca(ClO4)2. We measured supercooling by monitoring solution temperatures during slow cooling and warming experiments. Our results indicate that supercooling is pervasive. Slowly cooled MgSO4, MgCl2, NaCl, and NaClO4 solutions typically supercool 5-15°C below their eutectic temperature before crystallizing. The addition of soil to these salt solutions has a variable effect on supercooling. Relative to the pure salt solutions, supercooling decreases in MgSO4 soil solutions, increases in MgCl2 soil solutions, and is similar in NaCl and NaClO4 soil solutions. Supercooling in MgSO4, MgCl2, NaCl, and NaClO4 solutions could marginally extend the duration of liquid water during relatively warm daytime temperatures in the Martian summer. Remarkably, we found that Mg(ClO4)2 and Ca(ClO4)2 solutions never crystallize during slow cooling, but remain in a supercooled, liquid state until forming an amorphous glass near -120°C. Even if soil is added to the solutions, which will induce crystallization in most salt solutions, a glass still forms during cooling. The large supercooling effect in Mg(ClO4)2 and Ca(ClO4)2 solutions has the potential to prevent water from freezing over diurnal and possibly annual cycles on Mars. Glasses are

  12. Ion association in natural brines

    USGS Publications Warehouse

    Truesdell, A.H.; Jones, B.F.

    1969-01-01

    Natural brines, both surface and subsurface, are highly associated aqueous solutions. Ion complexes in brines may be ion pairs in which the cation remains fully hydrated and the bond between the ions is essentially electrostatic, or coordination complexes in which one or more of the hydration water molecules are replaced by covalent bonds to the anion. Except for Cl-, the major simple ions in natural brines form ion pairs; trace and minor metals in brines form mainly coordination complexes. Limitations of the Debye-Hu??ckel relations for activity coefficients and lack of data on definition and stability of all associated species in concentrated solutions tend to produce underestimates of the degree of ion association, except where the brines contain a very high proportion of Cl-. Data and calculations on closed basin brines of highly varied composition have been coupled with electrode measurements of single-ion activities in an attempt to quantify the degree of ion association. Such data emphasize the role of magnesium complexes. Trace metal contents of closed basin brines are related to complexes formed with major anions. Alkaline sulfo- or chlorocarbonate brines (western Great Basin) carry significant trace metal contents apparently as hydroxides or hydroxy polyions. Neutral high chloride brines (Bonneville Basin) are generally deficient in trace metals. With a knowledge of the thermodynamic properties of a natural water, many possible reactions with other phases (solids, gases, other liquids) may be predicted. A knowledge of these reactions is particularly important in the study of natural brines which may be saturated with many solid phases (silicates, carbonates, sulfates, etc.), which may have a high pH and bring about dissolution of other phases (silica, amphoteric hydroxides, CO2, etc.), and which because of their high density may form relatively stable interfaces with dilute waters. ?? 1969.

  13. High-temperature sensor

    DOEpatents

    Not Available

    1981-01-29

    A high temperature sensor is described which includes a pair of electrical conductors separated by a mass of electrical insulating material. The insulating material has a measurable resistivity within the sensor that changes in relation to the temperature of the insulating material within a high temperature range (1000 to 2000/sup 0/K). When required, the sensor can be encased within a ceramic protective coating.

  14. Imaging an Englacial Brine Conduit within a -17°C Polar Glacier

    NASA Astrophysics Data System (ADS)

    Badgeley, J.; Pettit, E. C.; Carr, C. G.; Tulaczyk, S. M.; Mikucki, J.

    2015-12-01

    Despite cold ice, there is evidence of an active zone of englacial brine that taps the subglacial brine reservoir of Taylor Glacier, McMurdo Dry Valleys (average annual air temperature -17°C). As part of the MIDGE (Minimally Invasive Direct Glacial Exploration) project, our geophysical study aims to reveal the hydraulic path of brine through Taylor Glacier prior to surface discharge at Blood Falls. We collected ground-penetrating-radar surveys at the terminus of Taylor Glacier that show a horizontal, linear scattering zone, the first evidence for englacial brine near Blood Falls. The scattering zone extends from Blood Falls upglacier and its trend matches that of past brine discharge cracks. By measuring depression of the basal ice reflector, we estimate a > 4% liquid brine content at the edge of the englacial scattering zone, assuming even dispersal of water within the ice column extending from the top of the scattering zone to the basal reflector. The brine content likely increases towards the center of the scattering zone as the underlying, depressed basal reflector disappears altogether. The concentration of brine at the center of the scattering zone may involve processes such at cryoconcentration and active input of brine from a nearby source. We use hydraulic potential models to map the source pathway of the englacial brine; the glacier's significant surface relief drives channelization of subglacial fluids. On the northern side of the eastward flowing glacier, channeled fluids are trapped between ice-cored moraines to the north and east and an area of high hydraulic potential to the south. The trapped fluids pond beneath and upglacier from Blood Falls and provide a likely source pool for the observed englacial brine. Although Blood Falls is a unique feature, our results suggest that polar glaciers can support subglacial and englacial hydraulic systems despite a temperature difference between the ice and the brine of nearly 10°C.

  15. How is a Brine Pool/Lake Maintained at Seafloor?

    NASA Astrophysics Data System (ADS)

    Xu, W.

    2009-12-01

    Highly saline brine pools or lakes have been found at seafloor, mostly associated with a sharp interface of fluid density at their top and often accompanied by high gas concentration of overlain water column and mud/gas venting from below. The occurrence of such brine layer between the seafloor and the overlain seawater may be the result of a vigorous double-diffusive convection within it. This double-diffusive convection is both promoted by a heating from below and suppressed by an upward-decreasing salinity gradient across it. The stability of a hydrostatic brine layer can be analyzed using the Rayleigh number modified by including the salinity effect. The maximum salinity difference is limited by the temperature difference across the brine layer, which supports the occurrence of multiple double-diffusive convection layers in larger brine lakes. Many researchers have suggested that the source of the brine is the salt dissolved from underlain salt dome and carried upwards by convection fluids. However, it is more difficult for fluid convection to occur below than above the seafloor due to both the resistance to fluid flow by and the enhanced salinity stabilization in porous medium. The maximum salinity gradient associated with such convection is further limited to a small number, which makes such convection almost impossible to occur near a salt dome, contrary to what most people believe. Consequently, the salt accumulated in a brine pool or lake must be carried up from below by a different mechanism, most likely an upward gas flow. This explains the fact that most seafloor brine pools/lakes are associated with overlain water column with a high gas (mostly methane) concentration. A possible source of the gas may be related to dissociating natural gas hydrates in depth. Another question is how the sharp interface between a brine pool/lake and the overlain water column is maintained. Without such a mechanism the interface, even if existed earlier, will be smoothed

  16. Improved methylene blue two-phase titration method for determining cationic surfactant concentration in high-salinity brine.

    PubMed

    Cui, Leyu; Puerto, Maura; López-Salinas, José L; Biswal, Sibani L; Hirasaki, George J

    2014-11-18

    The methylene blue (MB) two-phase titration method is a rapid and efficient method for determining the concentrations of anionic surfactants. The point at which the aqueous and chloroform phases appear equally blue is called Epton's end point. However, many inorganic anions, e.g., Cl(-), NO3(-), Br(-), and I(-), can form ion pairs with MB(+) and interfere with Epton's end point, resulting in the failure of the MB two-phase titration in high-salinity brine. Here we present a method to extend the MB two-phase titration method for determining the concentration of various cationic surfactants in both deionized water and high-salinity brine (22% total dissolved solid). A colorless end point, at which the blue color is completely transferred from the aqueous phase to the chloroform phase, is proposed as titration end point. Light absorbance at the characteristic wavelength of MB is measured using a spectrophotometer. When the absorbance falls below a threshold value of 0.04, the aqueous phase is considered colorless, indicating that the end point has been reached. By using this improved method, the overall error for the titration of a permanent cationic surfactant, e.g., dodecyltrimethylammonium bromide, in deionized (DI) water and high-salinity brine is 1.274% and 1.322% with limits of detection (LOD) of 0.149 and 0.215 mM, respectively. Compared to the traditional acid-base titration method, the error of this improved method for a switchable cationic surfactant, e.g., tertiary amine surfactant (Ethomeen C12), is 2.22% in DI water and 0.106% with LOD of 0.369 and 0.439 mM, respectively.

  17. Prospects of development of highly mineralized high-temperature resources of the Tarumovskoye geothermal field

    NASA Astrophysics Data System (ADS)

    Alkhasov, A. B.; Alkhasova, D. A.; Ramazanov, A. Sh.; Kasparova, M. A.

    2016-06-01

    The promising nature of integrated processing of high-temperature geothermal brines of the Tarumovskoye geothermal field is shown. Thermal energy of a geothermal brine can be converted to the electric power at a binary geothermal power plant (GPP) based on low-boiling working substance. The thermodynamic Rankine cycles are considered which are implemented in the GPP secondary loop at different evaporation temperatures of the working substance―isobutane. Among them, the most efficient cycle from the standpoint of attaining a maximum power is the supercritical one which is close to the so-called triangular cycle with an evaporation pressure of p e = 5.0 MPa. The used low-temperature brine is supplied from the GPP to a chemical plant, where main chemical components (lithium carbonate, burnt magnesia, calcium carbonate, and sodium chloride) are extracted from it according to the developed technology of comprehensive utilization of geothermal brines of chloride-sodium type. The waste water is delivered to the geotechnological complex and other consumers. For producing valuable inorganic materials, the electric power generated at the GPP is used. Owing to this, the total self-sufficiency of production and independence from external conditions is achieved. The advantages of the proposed geotechnological complex are the full utilization of the heat potential and the extraction of main chemical components of multiparameter geothermal resources. In this case, there is no need for reverse pumping, which eliminates the significant capital costs for building injection wells and a pumping station and the operating costs for their service. A characteristic of the modern state of the field and estimated figures of the integrated processing of high-temperature brines of well no. 6 are given, from which it follows that the proposed technology has a high efficiency. The comprehensive development of the field resources will make it possible to improve the economic structure of the

  18. High-Temperature Superconductivity

    SciTech Connect

    Peter Johnson

    2008-11-05

    Like astronomers tweaking images to gain a more detailed glimpse of distant stars, physicists at Brookhaven National Laboratory have found ways to sharpen images of the energy spectra in high-temperature superconductors — materials that carry electrical c

  19. High Temperature Capacitor Development

    SciTech Connect

    John Kosek

    2009-06-30

    The absence of high-temperature electronics is an obstacle to the development of untapped energy resources (deep oil, gas and geothermal). US natural gas consumption is projected to grow from 22 trillion cubic feet per year (tcf) in 1999 to 34 tcf in 2020. Cumulatively this is 607 tcf of consumption by 2020, while recoverable reserves using current technology are 177 tcf. A significant portion of this shortfall may be met by tapping deep gas reservoirs. Tapping these reservoirs represents a significant technical challenge. At these depths, temperatures and pressures are very high and may require penetrating very hard rock. Logistics of supporting 6.1 km (20,000 ft) drill strings and the drilling processes are complex and expensive. At these depths up to 50% of the total drilling cost may be in the last 10% of the well depth. Thus, as wells go deeper it is increasingly important that drillers are able to monitor conditions down-hole such as temperature, pressure, heading, etc. Commercial off-the-shelf electronics are not specified to meet these operating conditions. This is due to problems associated with all aspects of the electronics including the resistors and capacitors. With respect to capacitors, increasing temperature often significantly changes capacitance because of the strong temperature dependence of the dielectric constant. Higher temperatures also affect the equivalent series resistance (ESR). High-temperature capacitors usually have low capacitance values because of these dielectric effects and because packages are kept small to prevent mechanical breakage caused by thermal stresses. Electrolytic capacitors do not operate at temperatures above 150oC due to dielectric breakdown. The development of high-temperature capacitors to be used in a high-pressure high-temperature (HPHT) drilling environment was investigated. These capacitors were based on a previously developed high-voltage hybridized capacitor developed at Giner, Inc. in conjunction with a

  20. High temperature pressure gauge

    DOEpatents

    Echtler, J. Paul; Scandrol, Roy O.

    1981-01-01

    A high temperature pressure gauge comprising a pressure gauge positioned in fluid communication with one end of a conduit which has a diaphragm mounted in its other end. The conduit is filled with a low melting metal alloy above the diaphragm for a portion of its length with a high temperature fluid being positioned in the remaining length of the conduit and in the pressure gauge.

  1. High-temperature electronics

    NASA Technical Reports Server (NTRS)

    Matus, Lawrence G.; Seng, Gary T.

    1990-01-01

    To meet the needs of the aerospace propulsion and space power communities, the high temperature electronics program at the Lewis Research Center is developing silicon carbide (SiC) as a high temperature semiconductor material. This program supports a major element of the Center's mission - to perform basic and developmental research aimed at improving aerospace propulsion systems. Research is focused on developing the crystal growth, characterization, and device fabrication technologies necessary to produce a family of SiC devices.

  2. High Temperature ESP Monitoring

    SciTech Connect

    Jack Booker; Brindesh Dhruva

    2011-06-20

    The objective of the High Temperature ESP Monitoring project was to develop a downhole monitoring system to be used in wells with bottom hole well temperatures up to 300°C for measuring motor temperature, formation pressure, and formation temperature. These measurements are used to monitor the health of the ESP motor, to track the downhole operating conditions, and to optimize the pump operation. A 220 ºC based High Temperature ESP Monitoring system was commercially released for sale with Schlumberger ESP motors April of 2011 and a 250 ºC system with will be commercially released at the end of Q2 2011. The measurement system is now fully qualified, except for the sensor, at 300 °C.

  3. High temperature probe

    DOEpatents

    Swan, Raymond A.

    1994-01-01

    A high temperature probe for sampling, for example, smokestack fumes, and is able to withstand temperatures of 3000.degree. F. The probe is constructed so as to prevent leakage via the seal by placing the seal inside the water jacket whereby the seal is not exposed to high temperature, which destroys the seal. The sample inlet of the probe is also provided with cooling fins about the area of the seal to provide additional cooling to prevent the seal from being destroyed. Also, a heated jacket is provided for maintaining the temperature of the gas being tested as it passes through the probe. The probe includes pressure sensing means for determining the flow velocity of an efficient being sampled. In addition, thermocouples are located in various places on the probe to monitor the temperature of the gas passing there through.

  4. High temperature structural silicides

    SciTech Connect

    Petrovic, J.J.

    1997-03-01

    Structural silicides have important high temperature applications in oxidizing and aggressive environments. Most prominent are MoSi{sub 2}-based materials, which are borderline ceramic-intermetallic compounds. MoSi{sub 2} single crystals exhibit macroscopic compressive ductility at temperatures below room temperature in some orientations. Polycrystalline MoSi{sub 2} possesses elevated temperature creep behavior which is highly sensitive to grain size. MoSi{sub 2}-Si{sub 3}N{sub 4} composites show an important combination of oxidation resistance, creep resistance, and low temperature fracture toughness. Current potential applications of MoSi{sub 2}-based materials include furnace heating elements, molten metal lances, industrial gas burners, aerospace turbine engine components, diesel engine glow plugs, and materials for glass processing.

  5. High Temperature Piezoelectric Drill

    NASA Technical Reports Server (NTRS)

    Bao, Xiaoqi; Scott, James; Boudreau, Kate; Bar-Cohen, Yoseph; Sherrit, Stewart; Badescu, Mircea; Shrout, Tom; Zhang, Shujun

    2009-01-01

    The current NASA Decadal mission planning effort has identified Venus as a significant scientific target for a surface in-situ sampling/analyzing mission. The Venus environment represents several extremes including high temperature (460 deg C), high pressure (9 MPa), and potentially corrosive (condensed sulfuric acid droplets that adhere to surfaces during entry) environments. This technology challenge requires new rock sampling tools for these extreme conditions. Piezoelectric materials can potentially operate over a wide temperature range. Single crystals, like LiNbO3, have a Curie temperature that is higher than 1000 deg C and the piezoelectric ceramics Bismuth Titanate higher than 600 deg C. A study of the feasibility of producing piezoelectric drills that can operate in the temperature range up to 500 deg C was conducted. The study includes the high temperature properties investigations of engineering materials and piezoelectric ceramics with different formulas and doping. The drilling performances of a prototype Ultrasonic/Sonic Drill/Corer (USDC) using high temperate piezoelectric ceramics and single crystal were tested at temperature up to 500 deg C. The detailed results of our study and a discussion of the future work on performance improvements are presented in this paper.

  6. Performance and microbial diversity of an expanded granular sludge bed reactor for high sulfate and nitrate waste brine treatment.

    PubMed

    Liao, Runhua; Li, Yan; Yu, Xuemin; Shi, Peng; Wang, Zhu; Shen, Ke; Shi, Qianqian; Miao, Yu; Li, Wentao; Li, Aimin

    2014-04-01

    The disposal of waste brines has become a major challenge that hinders the wide application of ion-exchange resins in the water industry in recent decades. In this study, high sulfate removal efficiency (80%-90%) was achieved at the influent sulfate concentration of 3600 mg/L and 3% NaCl after 145 days in an expanded granular sludge bed (EGSB) reactor. Furthermore, the feasibility of treating synthetic waste brine containing high levels of sulfate and nitrate was investigated in a single EGSB reactor during an operation period of 261 days. The highest nitrate and sulfate loading rate reached 6.38 and 5.78 kg/(m(3)·day) at SO(2-)4-S/NO(-)3-N mass ratio of 4/3, and the corresponding removal efficiency was 99.97% and 82.26% at 3% NaCl, respectively. Meanwhile, 454-pyrosequencing technology was used to analyze the bacterial diversity of the sludge on the 240th day for stable operation of phase X. Results showed that a total of 9194 sequences were obtained, which could be affiliated to 14 phyla, including Proteobacteria, Firmicutes, Chlorobi, Bacteroidetes, Synergistetes and so on. Proteobacteria (77.66%) was the dominant microbial population, followed by Firmicutes (12.23%) and Chlorobi (2.71%).

  7. [Determination of alkylphenol and alkylphenolpolyethoxylates in brine by solid phase extraction and high performance liquid chromatography-mass spectrometry].

    PubMed

    Wang, Jincheng; Xiong, Li; Zhang, Haijun; Chen, Jiping

    2011-12-01

    A simple method based on solid phase extraction (SPE) coupled with high performance liquid chromatography-mass spectrometry (HPLC-MS) was developed for the determination of octylphenol (OP), nonylphenol (NP), octylphenol ethoxylates (OPEOs) and nonylphenol ethoxylates (NPEOs) in brine. The extraction and cleanup of brine samples were performed on C18 solid-phase extraction cartridges. The complete separation among OP, NP, OPEOs and NPEOs was achieved on a Hypersil GOLD analytical column with methanol-water as the mobile phase. The determination was achieved using HPLC-MS with electrospray ionization (ESI) in selected ion monitoring mode. The results showed that the average recoveries of target compounds were 59.6% - 104.4% and the corresponding relative standard deviations (RSDs, n = 3) were 1.0% - 13.5%. The instrumental limits of detection for the compounds were 0.08 - 3 microg/L. This method was applied to the analysis of the samples of seawater near Dalian coast. The results showed that both NP and NPEOs were detected in all samples and their concentrations in seaport and oil port were much higher than those in other sampling sites. PMID:22500440

  8. Mineralisation of amethyst-bearing geodes in Ametista do Sul (Brazil) from low-temperature sedimentary brines: evidence from monophase liquid inclusions and stable isotopes

    NASA Astrophysics Data System (ADS)

    Gilg, H. Albert; Krüger, Yves; Taubald, Heinrich; van den Kerkhof, Alfons M.; Frenz, Martin; Morteani, Giulio

    2014-10-01

    meteoric water line. This 18O-shift, high salinities of the fluid inclusions with chloride-sulphate composition, and high δ34S values of anhydrite and barite (7.5 to 9.9 ‰) suggest that sedimentary brines from deeper parts of the Guaraní aquifer system must have been responsible for the amethyst mineralisation.

  9. High temperature storage loop :

    SciTech Connect

    Gill, David Dennis; Kolb, William J.

    2013-07-01

    A three year plan for thermal energy storage (TES) research was created at Sandia National Laboratories in the spring of 2012. This plan included a strategic goal of providing test capability for Sandia and for the nation in which to evaluate high temperature storage (>650ÀC) technology. The plan was to scope, design, and build a flow loop that would be compatible with a multitude of high temperature heat transfer/storage fluids. The High Temperature Storage Loop (HTSL) would be reconfigurable so that it was useful for not only storage testing, but also for high temperature receiver testing and high efficiency power cycle testing as well. In that way, HTSL was part of a much larger strategy for Sandia to provide a research and testing platform that would be integral for the evaluation of individual technologies funded under the SunShot program. DOEs SunShot program seeks to reduce the price of solar technologies to 6/kWhr to be cost competitive with carbon-based fuels. The HTSL project sought to provide evaluation capability for these SunShot supported technologies. This report includes the scoping, design, and budgetary costing aspects of this effort

  10. High Temperature Structural Foam

    NASA Technical Reports Server (NTRS)

    Weiser, Erik S.; Baillif, Faye F.; Grimsley, Brian W.; Marchello, Joseph M.

    1997-01-01

    The Aerospace Industry is experiencing growing demand for high performance polymer foam. The X-33 program needs structural foam insulation capable of retaining its strength over a wide range of environmental conditions. The High Speed Research Program has a need for low density core splice and potting materials. This paper reviews the state of the art in foam materials and describes experimental work to fabricate low density, high shear strength foam which can withstand temperatures from -220 C to 220 C. Commercially available polymer foams exhibit a wide range of physical properties. Some with densities as low as 0.066 g/cc are capable of co-curing at temperatures as high as 182 C. Rohacell foams can be resin transfer molded at temperatures up to 180 C. They have moduli of elasticity of 0.19 MPa, tensile strengths of 3.7 Mpa and compressive strengths of 3.6 MPa. The Rohacell foams cannot withstand liquid hydrogen temperatures, however Imi-Tech markets Solimide (trademark) foams which withstand temperatures from -250 C to 200 C, but they do not have the required structural integrity. The research activity at NASA Langley Research Center focuses on using chemical blowing agents to produce polyimide thermoplastic foams capable of meeting the above performance requirements. The combination of blowing agents that decompose at the minimum melt viscosity temperature together with plasticizers to lower the viscosity has been used to produce foams by both extrusion and oven heating. The foams produced exhibit good environmental stability while maintaining structural properties.

  11. High-Temperature Superconductivity

    ScienceCinema

    Peter Johnson

    2016-07-12

    Like astronomers tweaking images to gain a more detailed glimpse of distant stars, physicists at Brookhaven National Laboratory have found ways to sharpen images of the energy spectra in high-temperature superconductors — materials that carry electrical c

  12. HIGH TEMPERATURE THERMOCOUPLE

    DOEpatents

    Eshayu, A.M.

    1963-02-12

    This invention contemplates a high temperature thermocouple for use in an inert or a reducing atmosphere. The thermocouple limbs are made of rhenium and graphite and these limbs are connected at their hot ends in compressed removable contact. The rhenium and graphite are of high purity and are substantially stable and free from diffusion into each other even without shielding. Also, the graphite may be thick enough to support the thermocouple in a gas stream. (AEC)

  13. High temperature thermometric phosphors

    DOEpatents

    Allison, Stephen W.; Cates, Michael R.; Boatner, Lynn A.; Gillies, George T.

    1999-03-23

    A high temperature phosphor consists essentially of a material having the general formula LuPO.sub.4 :Dy.sub.(x),Eu.sub.y) wherein: 0.1 wt %.ltoreq.x.ltoreq.20 wt % and 0.1 wt %.ltoreq.y.ltoreq.20 wt %. The high temperature phosphor is in contact with an article whose temperature is to be determined. The article having the phosphor in contact with it is placed in the environment for which the temperature of the article is to be determined. The phosphor is excited by a laser causing the phosphor to fluoresce. The emission from the phosphor is optically focused into a beam-splitting mirror which separates the emission into two separate emissions, the emission caused by the dysprosium dopant and the emission caused by the europium dopent. The separated emissions are optically filtered and the intensities of the emission are detected and measured. The ratio of the intensity of each emission is determined and the temperature of the article is calculated from the ratio of the intensities of the separate emissions.

  14. High temperature thermometric phosphors

    DOEpatents

    Allison, S.W.; Cates, M.R.; Boatner, L.A.; Gillies, G.T.

    1999-03-23

    A high temperature phosphor consists essentially of a material having the general formula LuPO{sub 4}:Dy{sub x},Eu{sub y} wherein: 0.1 wt % {<=} x {<=} 20 wt % and 0.1 wt % {<=} y {<=} 20 wt %. The high temperature phosphor is in contact with an article whose temperature is to be determined. The article having the phosphor in contact with it is placed in the environment for which the temperature of the article is to be determined. The phosphor is excited by a laser causing the phosphor to fluoresce. The emission from the phosphor is optically focused into a beam-splitting mirror which separates the emission into two separate emissions, the emission caused by the dysprosium dopant and the emission caused by the europium dopant. The separated emissions are optically filtered and the intensities of the emission are detected and measured. The ratio of the intensity of each emission is determined and the temperature of the article is calculated from the ratio of the intensities of the separate emissions. 2 figs.

  15. High-order Cu(II) chloro-complexes in LiCl brines: Insights from density function theory and molecular dynamics

    NASA Astrophysics Data System (ADS)

    Li, Hui-Ji; Yi, Hai-Bo; Xu, Jia-Jia

    2015-09-01

    Cu(II) complexation by chloride is relevant to the transport of copper in near-surface geologic environments, yet the existence of high-order Cu(II) chloro-complexes still remains in dispute. In this study, the structure characteristics and stabilities of [CuClx]2-xaq (x = 3, 4, 5) complexes have been investigated using density functional theory (DFT) methods and molecular dynamics (MD) simulations. [CuCl3]- and [CuCl4]2- species can both be tracked, while the [CuCl5]3-aq complex cannot be recorded during MD simulations of trace Cu2+ in chloride-rich brines. DFT calculations indicate that contact ion pair (CIP) conformers of [CuCl3]- species are less stable than its solvent separated ion pair (SSIP) conformers, in which one Cl- stays in the second coordination sphere of the centered Cu2+. MD simulations also reveal that the SSIP conformer is apt to appear in the aqueous solution than its CIP conformer. It seems that the third Cl- is more likely in the second coordination shell of center Cu2+ in [CuCl3]-. Meanwhile, the characteristic peak around 385 nm resolved in UV-Vis spectra experiments, which was attributed to the [CuCl3]- complex, could also be resulted from some SSIP structures of the [CuCl3]- complex. In MD simulations, the complex [CuCl4]2-aq is found more stable than [CuCl3]-aq. The surrounding water molecules around [CuClx]2-xaq (x = 3, 4) enhance their stabilities in Cl- brines, especially for [CuCl4]2-aq. The hydration shell of [CuCl4]2-aq species is more intact than that of [CuCl3]2-aq, and the residence time of a water molecule in the second coordination sphere of Cu ion in the [CuCl4]2-aq complex is also obviously longer than that of [CuCl3]-aq. The [CuCl4]2-aq complex can even be recorded in the less concentrated (6.33 m) Cl- solution, while the [CuCl3]-aq complex is tracked only in the 16.32 m Cl- brine. Meanwhile, the possibilities of [CuCl3]-aq and [CuCl4]2-aq complexes found in 16.32 m Cl- solutions both decrease with increasing temperature

  16. High temperature adsorption measurements

    SciTech Connect

    Bertani, R.; Parisi, L.; Perini, R.; Tarquini, B.

    1996-12-31

    Adsorption phenomena are a rich and rather new field of study in geothermal research, in particular at very high temperature. ENEL is interested in the exploitation of geothermal regions with super-heated steam, and it is important to understand the behavior of water-rock interaction. We have analyzed in the 170-200{degrees}C temperature range four samples of Monteverdi cuttings; the next experimental effort will be at 220{degrees}C and over in 1996. The first results of the 1995 runs are collected in this paper. We can highlight four main items: (1) At relative pressures over 0.6 the capillarity forces are very important. (2) There is no significant temperature effect. (3) Adsorbed water can be present, and it is able to multiply by a factor of 15 the estimated reserve of super-heated steam only. (4) Pores smaller than 15 {Angstrom} do not contribute to the adsorbed mass.

  17. High temperature adsorption measurements

    SciTech Connect

    Bertani, R.; Parisi, L.; Perini, R.; Tarquini, B.

    1996-01-24

    Adsorption phenomena are a rich and rather new field of study in geothermal research, in particular at very high temperature. ENEL is interested in the exploitation of geothermal regions with superheated steam, and it is important to understand the behavior of water-rock interaction. We have analyzed in the 170-200 °C temperature range four samples of Monteverdi cuttings; the next experimental effort will be at 220 °C and over in 1996. The first results of the 1995 runs are collected in this paper. We can highlight four main items: 1. At relative pressures over 0.6 the capillarity forces are very important. 2. There is no significant temperature effect. 3. Adsorbed water can be present, and it is able to multiply by a factor of 15 the estimated reserve of super-heated steam only. 4. Pores smaller than 15 Å do not contribute to the adsorbed mass.

  18. High Temperature Thermosets

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M.

    1999-01-01

    A thermoset or network polymer is an organic material where the molecules are tied together through chemical bonds (crosslinks) and therefore they cannot move past one another. As a result, these materials exhibit a certain degree of dimensional stability. The chemical composition and the degree of crosslink density of the thermoset have a pronounced effect upon the properties. High temperature thermosets offer a favorable combination of properties that makes them attractive for many applications. Their most important features are the excellent processability particularly of the low molecular weight precusor forms, the chemical and solvent resistance and the dimensional stability. The market for high temperature thermosets will increase as new uses for them are uncovered and new thermosets with better combinations of properties are developed.

  19. High temperature future

    SciTech Connect

    Sheinkopf, K.

    1994-09-01

    During the past few years, there have been dramatic accomplishments and success of high temperature solar thermal systems and significant development of these systems. High temperature technologies, about 500 F and higher, such as dish engines, troughs, central receiver power towers and solar process heat systems, have been tested, demonstrated and used in an array of applications, including many cost-effective utility bulk power production and demand side supply projects in the United States. Large systems provide power and hot water to prisons, schools, nursing homes and other institutions. Joint ventures with industry, utility projects, laboratory design assistance and other activities are building a solid industry of US solar thermal systems ready for use today.

  20. High temperature materials characterization

    NASA Technical Reports Server (NTRS)

    Workman, Gary L.

    1990-01-01

    A lab facility for measuring elastic moduli up to 1700 C was constructed and delivered. It was shown that the ultrasonic method can be used to determine elastic constants of materials from room temperature to their melting points. The ease in coupling high frequency acoustic energy is still a difficult task. Even now, new coupling materials and higher power ultrasonic pulsers are being suggested. The surface was only scratched in terms of showing the full capabilities of either technique used, especially since there is such a large learning curve in developing proper methodologies to take measurements into the high temperature region. The laser acoustic system does not seem to have sufficient precision at this time to replace the normal buffer rod methodology.

  1. Brine shrimp lethality test active constituents and new highly oxygenated seco-prezizaane-type sesquiterpenes from Illicium merrillianum.

    PubMed

    Huang, Jian-Mei; Nakade, Kousuke; Kondo, Mamiko; Yang, Chun-Shu; Fukuyama, Yoshiyasu

    2002-01-01

    In the study of bioactive substances in Illicium plants, the methanol extract of I. merrillianum showed brine shrimp lethality test (BST) activity at 200 microg/ml. Bioassay-guided fractionation of the BST active fractions resulted in the isolation of 4-O-methyleudesm-11-en-4alpha-ol, eudesmol-11-en-4alpha-ol and (-)-hinokinin as potent BST active compounds. On the other hand, four new highly oxygenated seco-prezizaane-type sesquiterpenes, merrilliortholactone (1), 2alpha-hydroxycycloparvifloralone (2), 2alpha-hydroxycycloparviflorolide (3), and 2alpha-hydroxyanisatin (4) were isolated from the BST-inactive polar fractions. The structures of new compounds were elucidated by extensive analyses of spectral data. Furthermore, the absolute configuration of 3 was established by the modified Mosher's method. Compounds 1--4 showed neither BST activity at 100 microg/ml nor neurite outgrowth-promoting activity. PMID:11824575

  2. Better high temperature sealing

    SciTech Connect

    Adams, W.V.

    1987-01-01

    Acceptance of welded metal bellows designs, superior seal face materials and advancement of environmental control systems has extended the limits of mechanical seals to the operating limits of the process systems themselves. The nonpusher type welded metal bellows designs have overcome past seal hang-up problems. Material combinations such as silicon carbide versus silicon carbide and silicon carbide versus tungsten carbide have proven to be capable of handling the harsh abrasives encountered on high temperature sealing applications. Steam purges have done a good job of flushing away the deposits and sludges that form on the atmospheric side of the seal and cause seal hang-up. Today's field experience shows that hot water at temperatures up to 350/sup 0/F in the seal cavity can be handled with nothing more than a bypass flush per API piping plan 11 as long as adequate vapor pressure of the fluid is available. For temperatures above 350/sup 0/F, only moderate cooling is now required on hot water applications, where full cooling and a reduction of the seal cavity temperature to something below 180/sup 0/F were once necessary. Initially, the move towards high temperature seals was made for safety, long seal life and reliability reasons. Users wanted seals on their equipment that would avoid the danger of catastrophic seal failures in the event the environmental control systems failed. More recently, the economic advantages of running seals hot have been recognized. It is estimated that an annual savings of $1,000 per inch of shaft size can be realized for every 100/sup 0/F of cooling requirements that can be removed from the seal cavity. This cost savings is due to the elimination or reduction of energy sources used to cool the mechanical seal.

  3. Study of thermal-gradient-induced migration of brine inclusions in salt. Final report

    SciTech Connect

    Olander, D.R.

    1984-08-01

    Natural salt deposits, which are being considered for high-level waste disposal, contain a small volume fraction of water in the form of brine inclusions distributed throughout the salt. Radioactive decay heating of the nuclear wastes will impose a temperature gradient on the surrounding salt which mobilizes the brine inclusions. Inclusions filled completely with brine (the all-liquid inclusions) migrate up the temperature gradient and eventually accumulate brine near the buried waste forms. The brine may slowly corrode or degrade the waste forms, which is undesirable. Therefore it is important to consider the migration of brine inclusions in salt under imposed temperature gradients to properly evaluate the performance of a future salt repository for nuclear wastes. The migration velocities of the inclusions were found to be dependent on temperature, temperature gradient, and inclusion shape and size. The velocities were also dictated by the interfacial mass transfer resistance at brine/solid interface. This interfacial resistance depends on the dislocation density in the crystal, which in turn, depends on the axial compressive loading of the crystal. At low axial loads, the dependence between the velocity and temperature gradient is nonlinear. At high axial loads, the interfacial resistance is reduced and the migration velocity depends linearly on the temperature gradient. All-liquid inclusions filled with mixed brines were also studied. For gas-liquid inclusions, helium, air and argon were compared. Migration studies were also conducted on single crystallites of natural salt as well as in polycrystalline natural salt samples. The behavior of the inclusions at large-ange grain boundaries was observed.

  4. 7 CFR 58.422 - Brine tank.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ....422 Brine tank. The brine tank shall be constructed of suitable non-toxic material and should be... clean, well circulated, and of the proper strength and temperature for the variety of cheese being made. ... Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE...

  5. High temperature strain gages

    NASA Technical Reports Server (NTRS)

    Gregory, Otto J. (Inventor); You, Tao (Inventor)

    2011-01-01

    A ceramic strain gage based on reactively sputtered indium-tin-oxide (ITO) thin films is used to monitor the structural integrity of components employed in aerospace propulsion systems operating at temperatures in excess of 1500.degree. C. A scanning electron microscopy (SEM) of the thick ITO sensors reveals a partially sintered microstructure comprising a contiguous network of submicron ITO particles with well defined necks and isolated nanoporosity. Densification of the ITO particles was retarded during high temperature exposure with nitrogen thus stabilizing the nanoporosity. ITO strain sensors were prepared by reactive sputtering in various nitrogen/oxygen/argon partial pressures to incorporate more nitrogen into the films. Under these conditions, sintering and densification of the ITO particles containing these nitrogen rich grain boundaries was retarded and a contiguous network of nano-sized ITO particles was established.

  6. High Temperature Piezoelectric Drill

    NASA Technical Reports Server (NTRS)

    Bao, Xiaoqi; Bar-Cohen, Yoseph; Sherrit, Stewart; Badescu, Mircea; Shrout, Tom

    2012-01-01

    Venus is one of the planets in the solar systems that are considered for potential future exploration missions. It has extreme environment where the average temperature is 460 deg C and its ambient pressure is about 90 atm. Since the existing actuation technology cannot maintain functionality under the harsh conditions of Venus, it is a challenge to perform sampling and other tasks that require the use of moving parts. Specifically, the currently available electromagnetic actuators are limited in their ability to produce sufficiently high stroke, torque, or force. In contrast, advances in developing electro-mechanical materials (such as piezoelectric and electrostrictive) have enabled potential actuation capabilities that can be used to support such missions. Taking advantage of these materials, we developed a piezoelectric actuated drill that operates at the temperature range up to 500 deg C and the mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) configuration. The detailed results of our study are presented in this paper

  7. Instabilities of High Temperature Superconductors

    PubMed Central

    Matthias, B. T.; Corenzwit, E.; Cooper, A. S.; Longinotti, L. D.

    1971-01-01

    We have observed the transition temperature of both the cubic and tetragonal phases of several high-temperature β-W superconductors. The instability of the cubic lattice appears to be characteristic of high-temperature superconductors. PMID:16591897

  8. High temperature detonator

    DOEpatents

    Johnson, James O.; Dinegar, Robert H.

    1988-01-01

    A detonator assembly is provided which is usable at high temperatures about 300.degree. C. A detonator body is provided with an internal volume defining an anvil surface. A first acceptor explosive is disposed on the anvil surface. A donor assembly having an ignition element, an explosive material, and a flying plate, are placed in the body effective to accelerate the flying plate to impact the first acceptor explosive on the anvil for detonating the first acceptor explosive. A second acceptor explosive is eccentrically located in detonation relationship with the first acceptor explosive to thereafter effect detonation of a main charge.

  9. High temperature geophysical instrumentation

    SciTech Connect

    Hardee, H.C.

    1988-06-01

    The instrumentation development program was to proceed in parallel with scientific research and was driven by the needs of researchers. The development of these instruments has therefore included numerous geophysical field tests, many of which have resulted in the publication of scientific articles. This paper is a brief summary of some of the major geophysical instruments that have been developed and tested under the High Temperature Geophysics Program. These instruments are briefly described and references are given for further detailed information and for scientific papers that have resulted from the use of these instruments. 9 refs., 14 figs.

  10. High temperature drilling fluids

    SciTech Connect

    Stong, R.E.; Walinsky, S.W.

    1986-01-28

    This patent describes an aqueous drilling fluid suitable for high-temperature use. This fluid is composed of a water base. Clay is suspended in the base and from about 0.01-25 pounds per barrel total composition of a hydrolyzed terpolymer of maleic anhydride, styrene and a third monomer selected from acrylamide, methacrylamide, acrylic acid and metacrylic acid. The molar ratio of maleic anhydride to styrene to the third monomer is from about 30:10:60 to 50:40:10, and the alkali metal, ammonium and lower aliphatic amine salts thereof, the weight-average molecular weight of the hydrolyzed terpolymer is from about 500-10,000.

  11. Distillation Brine Purification for Resource Recovery Applications

    NASA Technical Reports Server (NTRS)

    Wheeler, Raymond M.

    2014-01-01

    Wastewater processing systems for space generate residual brine that contains water and salts that could be recovered to life support consumables. The project assessed the use of ion-exchange resins to selectively remove salts from wastewater treatment brines. The resins were then regenerated for additional use. The intention would be to generate a Na/K and CI rich or purified brine that would then be processed into high value chemicals, such as acids, bases, and/or bleach.

  12. Recovery of base materials from geothermal brines

    SciTech Connect

    Duyvesteyn, W.P.C.

    1993-07-20

    A process is described for the recovery of substantially pure Zn from a reservoir of geothermal brine confined under pressure at elevated temperature at subterranean levels, the brine also containing recoverable and mounts of lead and silver which comprises: tapping and bringing to the earth's surface a portion of the geothermal brine; allowing the brine to flash at atmospheric pressure to produce steam for use in the generation of electrical power; cooling the flashed brine; extracting Pb and Ag from the brine by cementation by adding a metal selected from the group consisting of Zn, Fe and Al to the cooled brine, removing the cemented Pb and Ag from the brine by solid/liquid separation; mixing the brine impoverished in the Pb and Ag with a substantially immiscible anionic solvent selective to the extraction of Zn to produce a spent brine and a Zn loaded anionic extractant; the anionic solvent being dissolved in a diluent of water immiscible organic solvent, recycling the spent brine to the reservoir of geothermal brine; subjecting the Zn-loaded anionic extractant to mixing with an aqueous solution to produce a Zn-loaded aqueous Zn chloride solution, separating the Zn-loaded aqueous solution from the anionic extractant, adjusting the pH of the Zn-containing aqueous solution, if necessary, to a pH sufficient to promote the separation of the Zn by cationic extraction, subjecting the Zn-loaded aqueous solution to extraction with a cationic solvent selective to Zn; the cationic solvent being dissolved in a diluent of a water-immiscible organic solvent, stripping the Zn from the loaded cationic extractant using a sulfuric acid electrolyte solution, the volume ratio of the cationic solvent to the sulfuric acid solution being such as to provide a Zn electrolyte solution of Zn concentration sufficient for the recovery of Zn therefrom, and then electrowinning the Zn from the electrolyte solution to provide a product of substantially pure Zn.

  13. High Temperature Protonic Conductors

    NASA Technical Reports Server (NTRS)

    Dynys, Fred; Berger, Marie-Helen; Sayir, Ali

    2007-01-01

    High Temperature Protonic Conductors (HTPC) with the perovskite structure are envisioned for electrochemical membrane applications such as H2 separation, H2 sensors and fuel cells. Successive membrane commercialization is dependent upon addressing issues with H2 permeation rate and environmental stability with CO2 and H2O. HTPC membranes are conventionally fabricated by solid-state sintering. Grain boundaries and the presence of intergranular second phases reduce the proton mobility by orders of magnitude than the bulk crystalline grain. To enhanced protonic mobility, alternative processing routes were evaluated. A laser melt modulation (LMM) process was utilized to fabricate bulk samples, while pulsed laser deposition (PLD) was utilized to fabricate thin film membranes . Sr3Ca(1+x)Nb(2-x)O9 and SrCe(1-x)Y(x)O3 bulk samples were fabricated by LMM. Thin film BaCe(0.85)Y(0.15)O3 membranes were fabricated by PLD on porous substrates. Electron microscopy with chemical mapping was done to characterize the resultant microstructures. High temperature protonic conduction was measured by impedance spectroscopy in wet air or H2 environments. The results demonstrate the advantage of thin film membranes to thick membranes but also reveal the negative impact of defects or nanoscale domains on protonic conductivity.

  14. High temperature filter materials

    SciTech Connect

    Alvin, M.A.; Lippert, T.E.; Bachovchin, D.M.; Tressler, R.E.

    1992-12-01

    Objectives of this program are to identify the potential long-term thermal/chemical effects that advanced coal-based power generating system environments have on the stability of porous ceramic filter materials, as well as to assess the influence of these effects on filter operating performance and life. We have principally focused our efforts on developing an understanding of the stability of the alumina/mullite filter material at high temperature (i.e., 870, 980, and 1100{degrees}C) under oxidizing conditions which contain gas phase alkali species. Testing has typically been performed in two continuous flow-through, high temperature test facilities at the Westinghouse Science and Technology Center, using 7 cm diameter {times} 6.4 mm thick discs. (Alvin, 1992) Each disc of ceramic filter material is exposed for periods of 100 to 3,000 hours in duration. Additional efforts have been performed at Westinghouse to broaden our understanding of the stability of cordierite, cordierite-silicon nitride, reaction and sintered silicon nitride, and clay bonded silicon carbide under similar simulated advanced coal fired process conditions. The results of these efforts are presented in this paper.

  15. High temperature filter materials

    SciTech Connect

    Alvin, M.A.; Lippert, T.E.; Bachovchin, D.M. . Science and Technology Center); Tressler, R.E. )

    1992-01-01

    Objectives of this program are to identify the potential long-term thermal/chemical effects that advanced coal-based power generating system environments have on the stability of porous ceramic filter materials, as well as to assess the influence of these effects on filter operating performance and life. We have principally focused our efforts on developing an understanding of the stability of the alumina/mullite filter material at high temperature (i.e., 870, 980, and 1100[degrees]C) under oxidizing conditions which contain gas phase alkali species. Testing has typically been performed in two continuous flow-through, high temperature test facilities at the Westinghouse Science and Technology Center, using 7 cm diameter [times] 6.4 mm thick discs. (Alvin, 1992) Each disc of ceramic filter material is exposed for periods of 100 to 3,000 hours in duration. Additional efforts have been performed at Westinghouse to broaden our understanding of the stability of cordierite, cordierite-silicon nitride, reaction and sintered silicon nitride, and clay bonded silicon carbide under similar simulated advanced coal fired process conditions. The results of these efforts are presented in this paper.

  16. The study of aluminium anodes for high power density Al/air batteries with brine electrolytes

    NASA Astrophysics Data System (ADS)

    Nestoridi, Maria; Pletcher, Derek; Wood, Robert J. K.; Wang, Shuncai; Jones, Richard L.; Stokes, Keith R.; Wilcock, Ian

    Aluminium alloys containing small additions of both tin (∼0.1 wt%) and gallium (∼0.05 wt%) are shown to dissolve anodically at high rates in sodium chloride media at room temperatures; current densities >0.2 A cm -2 can be obtained at potentials close to the open circuit potential, ∼-1500 mV versus SCE. The tin exists in the alloys as a second phase, typically as ∼1 μm inclusions (precipitates) distributed throughout the aluminium structure, and anodic dissolution occurs to form pits around the tin inclusions. Although the distribution of the gallium in the alloy could not be established, it is also shown to be critical in the formation of these pits as well as maintaining their activity. The stability of the alloys to open circuit corrosion and the overpotential for high rate dissolution, both critical to battery performance, are shown to depend on factors in addition to elemental composition; both heat treatment and mechanical working influence the performance of the alloy. The correlation between alloy performance and their microstructure has been investigated.

  17. On the viscosity of natural hyper-saline solutions and its importance: The Dead Sea brines

    NASA Astrophysics Data System (ADS)

    Weisbrod, Noam; Yechieli, Yoseph; Shandalov, Semion; Lensky, Nadav

    2016-01-01

    The relationship between the density, temperature and viscosity of hypersaline solutions, both natural and synthetic, is explored. An empirical equation of the density-viscosity relationship as a function of temperature was developed for the Dead Sea brine and its dilutions. The viscosity levels of the Dead Sea brine (density of 1.24 ṡ 103 kg/m3; viscosity of 3.6 mPa s at 20 °C) and of the more extremely saline natural brine (density of 1.37 ṡ 103 kg/m3) were found to be ∼3 and ∼10 times greater than that of fresh water, respectively. The combined effect of the above changes in viscosity and density on the hydraulic conductivity is reduction by a factor of 3-7. The chemical composition significantly affects the viscosity of brines with similar densities, whereby solutions with a higher Mg/Na ratio have higher viscosity. This explains the extremely high viscosity of the Dead Sea and related Mg-rich brines in comparison with the much lower values of NaCl and KCl brines with similar density. Possible impacts of the results include reduced settling velocity of grains in hypersaline viscous brines and changing hydraulic dynamics at the freshwater-saltwater and the vicinity of sinkholes.

  18. High Temperature Aquifer Storage

    NASA Astrophysics Data System (ADS)

    Ueckert, Martina; Niessner, Reinhard; Baumann, Thomas

    2015-04-01

    Combined heat and power generation (CHP) is highly efficient because excess heat is used for heating and/or process energy. However, the demand of heat energy varies considerably throughout the year while the demand for electrical energy is rather constant. It seems economically and ecologically highly beneficial for municipalities and large power consumers such as manufacturing plants to store excess heat in groundwater aquifers and to recuperate this energy at times of higher demand. Apart from the hydrogeological conditions, high transmissivity and favorable pressure gradients, the hydrochemical conditions are crucial for long-term operation. Within the project High Temperature Aquifer Storage, scientists investigate storage and recuperation of excess heat energy into the bavarian Malm aquifer. After one year of planning, construction, and the successful drilling of a research well to 495 m b.s.l. the first large scale heat storage test in the Malm aquifer was finished just before Christmas 2014. An enormous technical challenge was the disruption of the carbonate equilibrium - modeling results indicated a carbonate precipitation of 10-50 kg/d in the heat exchangers. The test included five injection pulses of hot water (60 °C up to 110 °C) and four tracer pulses, each consisting of a reactive and a conservative fluorescent dye. Injection and production rates were 15 L/s. About 4 TJ of heat energy were necessary to achieve the desired water temperatures. Electrical conductivity, pH and temperature were recorded at a bypass where also samples were taken. A laboratory container at the drilling site was equipped for the analysis of the concentration of the tracers and the cation concentrations at sampling intervals of down to 15 minutes. Additional water samples were taken and analyzed for major ions and trace elements in the laboratory. The disassembled heat exchanger proved that precipitation was successfully prevented by adding CO2 to the water before heating

  19. High Temperature Aquifer Storage

    NASA Astrophysics Data System (ADS)

    Ueckert, Martina; Niessner, Reinhard; Baumann, Thomas

    2016-04-01

    Combined heat and power generation (CHP) is highly efficient because excess heat is used for heating and/or process energy. However, the demand of heat energy varies considerably throughout the year while the demand for electrical energy is rather constant. It seems economically and ecologically highly beneficial for municipalities and large power consumers such as manufacturing plants to store excess heat in groundwater aquifers and to recuperate this energy at times of higher demand. Within the project High Temperature Aquifer Storage, scientists investigate storage and recuperation of excess heat energy into the bavarian Malm aquifer. Apart from high transmissivity and favorable pressure gradients, the hydrochemical conditions are crucial for long-term operation. An enormous technical challenge is the disruption of the carbonate equilibrium - modeling results indicated a carbonate precipitation of 10 - 50 kg/d in the heat exchangers. The test included five injection pulses of hot water (60 °C up to 110 °C) and four tracer pulses, each consisting of a reactive and a conservative fluorescent dye, into a depth of about 300 m b.s.l. resp. 470 m b.s.l. Injection and production rates were 15 L/s. To achieve the desired water temperatures, about 4 TJ of heat energy were necessary. Electrical conductivity, pH and temperature were recorded at a bypass where also samples were taken. A laboratory container at the drilling site was equipped for analysing the concentration of the dyes and the major cations at sampling intervals of down to 15 minutes. Additional water samples were taken and analysed in the laboratory. The disassembled heat exchanger prooved that precipitation was successfully prevented by adding CO2 to the water before heating. Nevertheless, hydrochemical data proved both, dissolution and precipitation processes in the aquifer. This was also suggested by the hydrochemical modelling with PhreeqC and is traced back to mixture dissolution and changing

  20. Sr isotope quantification of siderite, brine and AMD contribution to high TDS well discharges; in, Goldschmidt Abstracts 2010 – C

    SciTech Connect

    Chapman, E. C.; Capo, R. C.; Stewart, B. W.; Hedin, R, S.; Weaver, T. J.; Edenborn, H. M.; S, R,=

    2010-06-01

    Long abstract only. To assess their relative contributions, geochemical and strontium isotopic analyses were carried out on gas well discharges, groundwater, brines, AMD seeps, and siderite from sedimentary strata.

  1. High temperature interfacial superconductivity

    SciTech Connect

    Bozovic, Ivan; Logvenov, Gennady; Gozar, Adrian Mihai

    2012-06-19

    High-temperature superconductivity confined to nanometer-scale interfaces has been a long standing goal because of potential applications in electronic devices. The spontaneous formation of a superconducting interface in bilayers consisting of an insulator (La.sub.2CuO.sub.4) and a metal (La.sub.1-xSr.sub.xCuO.sub.4), neither of which is superconducting per se, is described. Depending upon the layering sequence of the bilayers, T.sub.c may be either .about.15 K or .about.30 K. This highly robust phenomenon is confined to within 2-3 nm around the interface. After exposing the bilayer to ozone, T.sub.c exceeds 50 K and this enhanced superconductivity is also shown to originate from a 1 to 2 unit cell thick interfacial layer. The results demonstrate that engineering artificial heterostructures provides a novel, unconventional way to fabricate stable, quasi two-dimensional high T.sub.c phases and to significantly enhance superconducting properties in other superconductors. The superconducting interface may be implemented, for example, in SIS tunnel junctions or a SuFET.

  2. Spontaneous imbibition of water by crude oil/brine/rock systems

    SciTech Connect

    Jadhunandan, P.P.; Morrow, N.R. )

    1991-01-01

    This paper reports on the effect of brine composition, crude oil type, and aging conditions on wettability measured by rate of spontaneous inhibition of water that has been investigated for Berea sandstone. Brines were formulated with sodium and calcium chloride. Two crude oil samples, Moutray from West Texas and ST-86, a North Sea crude oil, were employed. Changes in wettability caused by Moutray crude were sensitive to brine composition; water-wetness decreased as the calcium chloride concentration increased. For cores aged with ST-86, wettability was much less influenced by brine composition. Aging temperature and initial water saturation were dominant variables with respect to the wettability change induced by a given crude oil. Wettability with respect to water decreased as aging temperature increased. Decrease in initial water saturation resulted in a shift towards oil-wetness. Oil recovery by waterflooding for weakly water-wet systems was high compared to that for strongly water-wet systems.

  3. Mercuric reductase genes (merA) and mercury resistance plasmids in High Arctic snow, freshwater and sea-ice brine.

    PubMed

    Møller, Annette K; Barkay, Tamar; Hansen, Martin A; Norman, Anders; Hansen, Lars H; Sørensen, Søren J; Boyd, Eric S; Kroer, Niels

    2014-01-01

    Bacterial reduction in Hg(2+) to Hg(0) , mediated by the mercuric reductase (MerA), is important in the biogeochemical cycling of Hg in temperate environments. Little is known about the occurrence and diversity of merA in the Arctic. Seven merA determinants were identified among bacterial isolates from High Arctic snow, freshwater and sea-ice brine. Three determinants in Bacteriodetes, Firmicutes and Actinobacteria showed < 92% (amino acid) sequence similarity to known merA, while one merA homologue in Alphaproteobacteria and 3 homologues from Betaproteobacteria and Gammaproteobacteria were > 99% similar to known merA's. Phylogenetic analysis showed the Bacteroidetes merA to be part of an early lineage in the mer phylogeny, whereas the Betaproteobacteria and Gammaproteobacteria merA appeared to have evolved recently. Several isolates, in which merA was not detected, were able to reduce Hg(2+) , suggesting presence of unidentified merA genes. About 25% of the isolates contained plasmids, two of which encoded mer operons. One plasmid was a broad host-range IncP-α plasmid. No known incompatibility group could be assigned to the others. The presence of conjugative plasmids, and an incongruent distribution of merA within the taxonomic groups, suggests horizontal transfer of merA as a likely mechanism for High Arctic microbial communities to adapt to changing mercury concentration.

  4. Strong salinity gradients in the northeastern part of the Salton Sea geothermal field, CA: a fluid inclusion and brine chemistry study

    SciTech Connect

    Oakes, C.S.

    1985-01-01

    Geothermal wells in the northeastern Salton Sea geothermal field produce concentrated Na-Ca-K-Cl brines. Maximum dissolved constituents do not exceed 260,000 ppm. Fluid inclusion homogenization temperatures from cuttings of vein calcite and quartz are in close agreement with temperature logs and indicate maximum reservoir temperatures between 290/sup 0/ and 310/sup 0/C at 3140 to 3565 m. Melting temperatures of inclusion fluids indicate the trapping of both low salinity and high salinity vein-forming solutions. The high salinity inclusion fluids appear similar to the produced reservoir fluids in their total dissolved solids, while both high salinity and low salinity inclusions imply temperatures similar to that of the reservoir. The low salinity inclusions occur over broad intervals above and below the much less vertically extensive high salinity inclusion fluids. Although the presence of interstratified high salinity and low salinity brines should be gravitationally unstable, flow tests of one well, at varying well head pressures, produced two brines of distinctly different compositions. Consequently, the persistence of two different brines requires severe impedance of vertical permeability. Stratification of brines in this geothermal system carries significant implications for the formation models of some epithermal ore deposits by mixing of fluids of different salinity, pH, fO/sub 2/, fS/sub 2/, temperature, etc. Additionally, there are very strong economic advantages to the possible production of hot, dilute brines rather than the currently produced highly saline brines.

  5. Forward Osmosis Brine Drying

    NASA Technical Reports Server (NTRS)

    Flynn, Michael; Shaw, Hali; Hyde, Deirdre; Beeler, David; Parodi, Jurek

    2015-01-01

    The Forward Osmosis Brine Drying (FOBD) system is based on a technique called forward osmosis (FO). FO is a membrane-based process where the osmotic potential between brine and a salt solution is equalized by the movement of water from the brine to the salt solution. The FOBD system is composed of two main elements, the FO bag and the salt regeneration system. This paper discusses the results of testing of the FO bag to determine the maximum water recovery ratio that can be attained using this technology. Testing demonstrated that the FO bag is capable of achieving a maximum brine water recovery ratio of the brine of 95%. The equivalent system mass was calculated to be 95 kg for a feed similar to the concentrated brine generated on the International Space Station and 86 kg for an Exploration brine. The results have indicated that the FOBD can process all the brine for a one year mission for between 11% to 10% mass required to bring the water needed to make up for water lost in the brine if not recycled. The FOBD saves 685 kg and when treating the International Space Station brine and it saves 829 kg when treating the Exploration brine. It was also demonstrated that saturated salt solutions achieve a higher water recovery ratios than solids salts do and that lithium chloride achieved a higher water recovery ratio than sodium chloride.

  6. High Temperature Superconducting Materials Database

    National Institute of Standards and Technology Data Gateway

    SRD 149 NIST High Temperature Superconducting Materials Database (Web, free access)   The NIST High Temperature Superconducting Materials Database (WebHTS) provides evaluated thermal, mechanical, and superconducting property data for oxides and other nonconventional superconductors.

  7. High Temperature Thermoelectric Materials

    NASA Astrophysics Data System (ADS)

    Ioannidou, A. A.; Rull, M.; Martin-Gonzalez, M.; Moure, A.; Jacquot, A.; Niarchos, D.

    2014-07-01

    The use of microwave energy for materials processing has a major potential and real advantages over conventional heating such as (1) time and energy savings, (2) rapid heating rates (volumetric heating vs. conduction), (3) considerably reduced processing time and temperature, (4) fine microstructures and hence improved mechanical properties and better product performance, and (5) finally lower environmental impact. In this study, we investigated the use of microwave-assisted synthesis to synthesize a series of Co1- x Fe x Sb3 using this novel approach, which gave high quality materials with little or no impurities in a fraction of the time needed for conventional synthesis. X-ray diffraction analysis was used to examine the structure and the lattice parameters of the samples, while scanning electron microscopy with energy dispersive x-ray spectroscopy was used to study the morphology of the compounds. The samples were sintered by spark plasma sintering, and the highest ZT of 0.33 was obtained for x = 0.2 at 700 K.

  8. Experimental multi-phase CO2-brine-rock interactions at elevated temperature and pressure: Implications for CO2 sequestration in deep-saline aquifers

    USGS Publications Warehouse

    Rosenbauer, R.J.; Koksalan, T.

    2004-01-01

    Long-term CO2 saturated brine-rock experiments were conducted to evaluate the effects of multiphase H2O-CO2 fluids on mineral equilibria and the potential for CO2 sequestration mineral phases within deep-saline aquifers. Experimental results were consistent with theoretical thermodynamic calculations when CO2-saturated brines were reacted with limestone rocks. The CO2-saturated brine-limestone reactions were characterized by compositional and mineralogical-changes in the aquifer fluid and formation rocks that were dependent on initial brine composition as were the changes in formation porosity, especially dissolved sulfate. The solubility of CO2 was enhanced in brines in the presence of both limestone and sandstone rocks relative to brines alone. Reactions between CO2 saturated brines and arkosic sandstones were characterized by desiccation of the brine and changes in the chemical composition of the brine suggesting fixation of CO2 in mineral phases. These reactions occured on a measurable but kinetically slow time scale at 120??C.

  9. Viruses-to-mobile genetic elements skew in the deep Atlantis II brine pool sediments.

    PubMed

    Adel, Mustafa; Elbehery, Ali H A; Aziz, Sherry K; Aziz, Ramy K; Grossart, Hans-Peter; Siam, Rania

    2016-01-01

    The central rift of the Red Sea has 25 brine pools with different physical and geochemical characteristics. Atlantis II (ATIID), Discovery Deeps (DD) and Chain Deep (CD) are characterized by high salinity, temperature and metal content. Several studies reported microbial communities in these brine pools, but few studies addressed the brine pool sediments. Therefore, sediment cores were collected from ATIID, DD, CD brine pools and an adjacent brine-influenced site. Sixteen different lithologic sediment sections were subjected to shotgun DNA pyrosequencing to generate 1.47 billion base pairs (1.47 × 10(9) bp). We generated sediment-specific reads and attempted to annotate all reads. We report the phylogenetic and biochemical uniqueness of the deepest ATIID sulfur-rich brine pool sediments. In contrary to all other sediment sections, bacteria dominate the deepest ATIID sulfur-rich brine pool sediments. This decrease in virus-to-bacteria ratio in selected sections and depth coincided with an overrepresentation of mobile genetic elements. Skewing in the composition of viruses-to-mobile genetic elements may uniquely contribute to the distinct microbial consortium in sediments in proximity to hydrothermally active vents of the Red Sea and possibly in their surroundings, through differential horizontal gene transfer. PMID:27596223

  10. Viruses-to-mobile genetic elements skew in the deep Atlantis II brine pool sediments

    NASA Astrophysics Data System (ADS)

    Adel, Mustafa; Elbehery, Ali H. A.; Aziz, Sherry K.; Aziz, Ramy K.; Grossart, Hans-Peter; Siam, Rania

    2016-09-01

    The central rift of the Red Sea has 25 brine pools with different physical and geochemical characteristics. Atlantis II (ATIID), Discovery Deeps (DD) and Chain Deep (CD) are characterized by high salinity, temperature and metal content. Several studies reported microbial communities in these brine pools, but few studies addressed the brine pool sediments. Therefore, sediment cores were collected from ATIID, DD, CD brine pools and an adjacent brine-influenced site. Sixteen different lithologic sediment sections were subjected to shotgun DNA pyrosequencing to generate 1.47 billion base pairs (1.47 × 109 bp). We generated sediment-specific reads and attempted to annotate all reads. We report the phylogenetic and biochemical uniqueness of the deepest ATIID sulfur-rich brine pool sediments. In contrary to all other sediment sections, bacteria dominate the deepest ATIID sulfur-rich brine pool sediments. This decrease in virus-to-bacteria ratio in selected sections and depth coincided with an overrepresentation of mobile genetic elements. Skewing in the composition of viruses-to-mobile genetic elements may uniquely contribute to the distinct microbial consortium in sediments in proximity to hydrothermally active vents of the Red Sea and possibly in their surroundings, through differential horizontal gene transfer.

  11. Viruses-to-mobile genetic elements skew in the deep Atlantis II brine pool sediments.

    PubMed

    Adel, Mustafa; Elbehery, Ali H A; Aziz, Sherry K; Aziz, Ramy K; Grossart, Hans-Peter; Siam, Rania

    2016-09-06

    The central rift of the Red Sea has 25 brine pools with different physical and geochemical characteristics. Atlantis II (ATIID), Discovery Deeps (DD) and Chain Deep (CD) are characterized by high salinity, temperature and metal content. Several studies reported microbial communities in these brine pools, but few studies addressed the brine pool sediments. Therefore, sediment cores were collected from ATIID, DD, CD brine pools and an adjacent brine-influenced site. Sixteen different lithologic sediment sections were subjected to shotgun DNA pyrosequencing to generate 1.47 billion base pairs (1.47 × 10(9) bp). We generated sediment-specific reads and attempted to annotate all reads. We report the phylogenetic and biochemical uniqueness of the deepest ATIID sulfur-rich brine pool sediments. In contrary to all other sediment sections, bacteria dominate the deepest ATIID sulfur-rich brine pool sediments. This decrease in virus-to-bacteria ratio in selected sections and depth coincided with an overrepresentation of mobile genetic elements. Skewing in the composition of viruses-to-mobile genetic elements may uniquely contribute to the distinct microbial consortium in sediments in proximity to hydrothermally active vents of the Red Sea and possibly in their surroundings, through differential horizontal gene transfer.

  12. Viruses-to-mobile genetic elements skew in the deep Atlantis II brine pool sediments

    PubMed Central

    Adel, Mustafa; Elbehery, Ali H. A.; Aziz, Sherry K.; Aziz, Ramy K.; Grossart, Hans-Peter; Siam, Rania

    2016-01-01

    The central rift of the Red Sea has 25 brine pools with different physical and geochemical characteristics. Atlantis II (ATIID), Discovery Deeps (DD) and Chain Deep (CD) are characterized by high salinity, temperature and metal content. Several studies reported microbial communities in these brine pools, but few studies addressed the brine pool sediments. Therefore, sediment cores were collected from ATIID, DD, CD brine pools and an adjacent brine-influenced site. Sixteen different lithologic sediment sections were subjected to shotgun DNA pyrosequencing to generate 1.47 billion base pairs (1.47 × 109 bp). We generated sediment-specific reads and attempted to annotate all reads. We report the phylogenetic and biochemical uniqueness of the deepest ATIID sulfur-rich brine pool sediments. In contrary to all other sediment sections, bacteria dominate the deepest ATIID sulfur-rich brine pool sediments. This decrease in virus-to-bacteria ratio in selected sections and depth coincided with an overrepresentation of mobile genetic elements. Skewing in the composition of viruses-to-mobile genetic elements may uniquely contribute to the distinct microbial consortium in sediments in proximity to hydrothermally active vents of the Red Sea and possibly in their surroundings, through differential horizontal gene transfer. PMID:27596223

  13. [The clinical results and lipid peroxidation dynamics in the patients presenting with psoriasis treated by the applications of a natural highly mineralized bromine-iodine brine].

    PubMed

    El'kin, V D; Koriukina, I P; Datskovskiĭ, Ia S; Plotnikova, E V

    2014-01-01

    The authors report the results of the treatment of 64 patients presenting with psoriasis by the applications of a natural highly mineralized bromine-iodine brine. The method has been shown to be highly efficacious and safe. It allowed the clinical remission and marked improvement of the patients' clinical conditions to be achieved in 48 (77.4%) cases compared with 10 (27.8%) cases among the patients of the control group. Exacerbation was documented in a single patient with psoriatic erythrodermia. All the patients showed the normal results of general and biochemical clinical analyses of blood and urea throughout the study period. The applications of the natural highly mineralized bromine-iodine brine exerted the normalizing action on seven of the 8 characteristics of the lipid peroxidation process. It is maintained that the high effectiveness of the method in question can be accounted not only by the reflectory and humoral mechanisms of action of highly mineralized bromine-iodine brine but also by the marked exhaustion of the functional reserves of the mast cells under effect of the applications. It is concluded that an advantage of the proposed approach over standard balneotherapeutic procedures consists of the possibility to employ it not only at the base of a spa and health resort facility but also in a different setting with the involvement of the patients suffering from progressive psoriasis.

  14. Sr Isotope Quantification of Deep Brine and Shallow Acidic Coal Mine Drainage Inputs to High TDS Gas Well Discharges in Western Pennsylvania

    NASA Astrophysics Data System (ADS)

    Chapman, E.; Capo, R.; Stewart, B. W.; Hedin, R.; Weaver, T.

    2009-12-01

    Chapman, E. C., Capo. R. C., Stewart, B. W. Dept. of Geology & Planetary Science, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260 Hedin, R. S. and Weaver, T. R., Hedin Environmental, 195 Castle Shannon Blvd., Pittsburgh, Pennsylvania, 15228 In western Pennsylvania, numerous abandoned oil and gas wells discharge contaminated water to the surface. Many of these discharges have circumneutral pH as well as high concentrations of iron and sulfate. Total dissolved solid (TDS) content is also high relative to local groundwater. Possible sources of this water include deep brines, which have circumneutral pH and very high TDS, or shallow acidic coal mine drainage (AMD). Hundreds of hilltop strip mines are found in this area, and mine seeps have low pH (3.5-4) and high TDS. Geochemical data alone have not been definitive in determining the source of the gas well discharges. Strontium isotopic compositions of deep brine, gas well discharges drilled 150-240 m deep into Upper Devonian strata, and local AMD associated with the Leeper anticline in Clarion County strongly suggest that the water chemistry in the gas wells is dominated (>99%) by mine drainage. Because of its high Sr concentrations, even small contributions of brine (<1%) can significantly change the 87Sr/86Sr of the groundwater. With the ability to determine the source of these discharges, other questions about subsurface geochemical reactions can be addressed. For example, iron concentration in the gas well discharges is much higher than either the deep brines or shallow AMD. This could be due to siderite (FeCO3) dissolution by AMD; previous work identified the presence of siderite in sedimentary strata within the subsurface path of the AMD flows. Carbonate mineral dissolution could also explain the circumneutral pH of flows from the gas wells. Sr isotopes can be used as a sensitive tracer for the interaction of shallow and deep fossil fuel byproducts with natural waters, including produced waters from

  15. Vacuum membrane distillation of seawater reverse osmosis brines.

    PubMed

    Mericq, Jean-Pierre; Laborie, Stéphanie; Cabassud, Corinne

    2010-10-01

    Seawater desalination by Reverse Osmosis (RO) is an interesting solution for drinking water production. However, because of limitation by the osmotic pressure, a high recovery factor is not attainable. Consequently, large volumes of brines are discharged into the sea and the flow rate produced (permeate) is limited. In this paper, Vacuum Membrane Distillation (VMD) is considered as a complementary process to RO to further concentrate RO brines and increase the global recovery of the process. VMD is an evaporative technology that uses a membrane to support the liquid-vapour interface and enhance the contact area between liquid and vapour in comparison with conventional distillation. This study focuses on VMD for the treatment of RO brines. Simulations were performed to optimise the operating conditions and were completed by bench-scale experiments using actual RO brines and synthetic solutions up to a salt concentration of 300 g L(-1). Operating conditions such as a highly permeable membrane, high feed temperature, low permeate pressure and a turbulent fluid regime allowed high permeate fluxes to be obtained even for a very high salt concentration (300 g L(-1)). For the membrane studied, temperature and concentration polarisation were shown to have little effect on permeate flux. After 6 to 8 h, no organic fouling or biofouling was observed for RO brines. At high salt concentrations, scaling occurred (mainly due to calcium precipitation) but had only a limited impact on the permeate flux (24% decrease for a permeate specific volume of 43L m(-2) for the highest concentration of salt). Calcium carbonate and calcium sulphate precipitated first due to their low solubility and formed mixed crystal deposits on the membrane surface. These phenomena only occurred on the membrane surface and did not totally cover the pores. The crystals were easily removed simply by washing the membrane with water. A global recovery factor of 89% can be obtained by coupling RO and VMD.

  16. High-temperature piezoelectric sensing.

    PubMed

    Jiang, Xiaoning; Kim, Kyungrim; Zhang, Shujun; Johnson, Joseph; Salazar, Giovanni

    2013-01-01

    Piezoelectric sensing is of increasing interest for high-temperature applications in aerospace, automotive, power plants and material processing due to its low cost, compact sensor size and simple signal conditioning, in comparison with other high-temperature sensing techniques. This paper presented an overview of high-temperature piezoelectric sensing techniques. Firstly, different types of high-temperature piezoelectric single crystals, electrode materials, and their pros and cons are discussed. Secondly, recent work on high-temperature piezoelectric sensors including accelerometer, surface acoustic wave sensor, ultrasound transducer, acoustic emission sensor, gas sensor, and pressure sensor for temperatures up to 1,250 °C were reviewed. Finally, discussions of existing challenges and future work for high-temperature piezoelectric sensing are presented. PMID:24361928

  17. High-Temperature Piezoelectric Sensing

    PubMed Central

    Jiang, Xiaoning; Kim, Kyungrim; Zhang, Shujun; Johnson, Joseph; Salazar, Giovanni

    2014-01-01

    Piezoelectric sensing is of increasing interest for high-temperature applications in aerospace, automotive, power plants and material processing due to its low cost, compact sensor size and simple signal conditioning, in comparison with other high-temperature sensing techniques. This paper presented an overview of high-temperature piezoelectric sensing techniques. Firstly, different types of high-temperature piezoelectric single crystals, electrode materials, and their pros and cons are discussed. Secondly, recent work on high-temperature piezoelectric sensors including accelerometer, surface acoustic wave sensor, ultrasound transducer, acoustic emission sensor, gas sensor, and pressure sensor for temperatures up to 1,250 °C were reviewed. Finally, discussions of existing challenges and future work for high-temperature piezoelectric sensing are presented. PMID:24361928

  18. Spectroscopy and detectability of liquid brines on mars

    NASA Astrophysics Data System (ADS)

    Massé, M.; Beck, P.; Schmitt, B.; Pommerol, A.; McEwen, A.; Chevrier, V.; Brissaud, O.; Séjourné, A.

    2014-03-01

    Recent geomorphological observations as well as chemical and thermodynamic studies demonstrate that liquid water should be stable today on the Martian surface at some times of the day. In Martian conditions, brines would be particularly more stable than pure water because salts can depress the freezing point and lower the evaporation rate of water. Despite this evidence, no clear spectral signature of liquid has been observed so far by the hyperspectral imaging spectrometers OMEGA and CRISM. However, past spectral analysis lacks a good characterization of brines' spectral signatures. This study thus aims to determine how liquid brines can be detected on Mars by spectroscopy. In this way, laboratory experiments were performed for reproducing hydration and dehydration cycles of various brines while measuring their spectral signatures. The resulting spectra first reveal a very similar spectral evolution for the various brine types and pure water, with the main difference observed at the end of the dehydration with the crystallization of various hydrated minerals from brines. The main characteristic of this spectral behavior is an important decoupling between the evolution of albedo and hydration bands depths. During most of the wetting/drying processes, spectra usually display a low albedo associated with shallow water absorption band depths. Strong water absorption band depth and high albedo are respectively only observed when the surface is very wet and when the surface is very dry. These experiments can thus explain why the currently active Martian features attributed to the action of a liquid are only associated with low albedo and very weak spectral signatures. Hydration experiments also reveal that deliquescence occurs easily even at low temperature and moderate soil water vapor pressure and could thus cause seasonal darkening on Mars. These experiments demonstrate that the absence of water absorptions in CRISM in the middle afternoon does not rule out water

  19. Gas content of Gladys McCall reservoir brine

    SciTech Connect

    Hayden, C.G.; Randolph, P.L.

    1987-05-29

    On October 8, 1983, after the first full day of production from Sand No.8 in the Gladys McCall well, samples of separator gas and separator brine were collected for laboratory P-V-T (pressure, volume, temperature) studies. Recombination of amounts of these samples based upon measured rates at the time of sample collection, and at reservoir temperature (290 F), revealed a bubble point pressure of 9200 psia. This is substantially below the reported reservoir pressure of 12,783 psia. The gas content of the recombined fluids was 30.19 SCF of dry gas/STB of brine. In contrast, laboratory studies indicate that 35.84 SCF of pure methane would dissolve in each STB of 95,000 mg/L sodium chloride brine. These results indicate that the reservoir brine was not saturated with natural gas. By early April, 1987, production of roughly 25 million barrels of brine had reduced calculated flowing bottomhole pressure to about 6600 psia at a brine rate of 22,000 STB/D. If the skin factor(s) were as high as 20, flowing pressure drop across the skin would still be only about 500 psi. Thus, some portion of the reservoir volume was believed to have been drawn down to below the bubble point deduced from the laboratory recombination of separator samples. When the pressure in a geopressured geothermal reservoir is reduced to below the bubble point pressure for solution gas, gas is exsolved from the brine flowing through the pores in the reservoir rock. This exsolved gas is trapped in the reservoir until the fractional gas saturation of pore volume becomes large enough for gas flow to commence through a continuous gas-filled channel. At the same time, the gas/brine ratio becomes smaller and the chemistry of the remaining solution gas changes for the brine from which gas is exsolved. A careful search was made for the changes in gas/brine ratio or solution gas chemistry that would accompany pressure dropping below the bubble point pressure. Changes of about the same magnitude as the scatter in

  20. Buoyancy effects on upward brine displacement caused by CO2 injection

    SciTech Connect

    Oldenburg, C.M.; Rinaldi, A.

    2010-01-15

    Upward displacement of brine from deep reservoirs driven by pressure increases resulting from CO{sub 2} injection for geologic carbon sequestration may occur through improperly sealed abandoned wells, through permeable faults, or through permeable channels between pinch-outs of shale formations. The concern about upward brine flow is that, upon intrusion into aquifers containing groundwater resources, the brine may degrade groundwater. Because both salinity and temperature increase with depth in sedimentary basins, upward displacement of brine involves lifting fluid that is saline but also warm into shallower regions that contain fresher, cooler water. We have carried out dynamic simulations using TOUGH2/EOS7 of upward displacement of warm, salty water into cooler, fresher aquifers in a highly idealized two-dimensional model consisting of a vertical conduit (representing a well or permeable fault) connecting a deep and a shallow reservoir. Our simulations show that for small pressure increases and/or high-salinity-gradient cases, brine is pushed up the conduit to a new static steady-state equilibrium. On the other hand, if the pressure rise is large enough that brine is pushed up the conduit and into the overlying upper aquifer, flow may be sustained if the dense brine is allowed to spread laterally. In this scenario, dense brine only contacts the lower-most region of the upper aquifer. In a hypothetical case in which strong cooling of the dense brine occurs in the upper reservoir, the brine becomes sufficiently dense that it flows back down into the deeper reservoir from where it came. The brine then heats again in the lower aquifer and moves back up the conduit to repeat the cycle. Parameter studies delineate steady-state (static) and oscillatory solutions and reveal the character and period of oscillatory solutions. Such oscillatory solutions are mostly a curiosity rather than an expected natural phenomenon because in nature the geothermal gradient prevents the

  1. Paleohydrologic record from lake brine on the southern High Plains, Texas

    USGS Publications Warehouse

    Sanford, W.E.; Wood, W.W.

    1995-01-01

    The timing of changes in the stage and salinity of Double Lakes of Lynn County, Texas, was estimated using dissolved-chloride profiles across an underlying shale layer. Lake conditions over the past 30 to 50 ka can be inferred from the chloride profiles by using the advective velocity of the pore water through the shale and an appropriate coefficient of molecular diffusion. The profiles suggest that net-evaporative conditions existed over the southern High Plains for the past 50 ka; a period of increasing salinity in the lake began at ~20 ka and reached current levels at ~5 ka. In addition, deflationary conditions were present for at least 4 ka, and likely began or were accelerated during the most recent altithermal period at ~5 ka. -from Authors

  2. Coiled Brine Recovery Assembly (CoBRA): A New Approach to Recovering Water from Wastewater Brines

    NASA Technical Reports Server (NTRS)

    Pensinger, Stuart J.

    2015-01-01

    Brine water recovery represents a current technology gap in water recycling for human spaceflight. The role of a brine processor is to take the concentrated discharge from a primary wastewater processor, called brine, and recover most of the remaining water from it. The current state-of-the-art primary processor is the ISS Urine Processor Assembly (UPA) that currently achieves 70% water recovery. Recent advancements in chemical pretreatments are expected to increase this to 85% in the near future. This is a welcome improvement, yet is still not high enough for deep space transit. Mission architecture studies indicate that at least 95% is necessary for a Mars mission, as an example. Brine water recovery is the technology that bridges the gap between 85% and 95%, and moves life support systems one step closer to full closure of the water loop. Several brine water recovery systems have been proposed for human spaceflight, most of them focused on solving two major problems: operation in a weightless environment, and management and containment of brine residual. Brine residual is the leftover byproduct of the brine recovery process, and is often a viscous, sticky paste, laden with crystallized solid particles. Due to the chemical pretreatments added to wastewater prior to distillation in a primary processor, these residuals are typically toxic, which further complicates matters. Isolation of crewmembers from these hazardous materials is paramount. The Coiled Brine Recovery Assembly (CoBRA) is a recently developed concept from the Johnson Space Center that offers solutions to these challenges. CoBRA is centered on a softgoods evaporator that enables a passive fill with brine, and regeneration by discharging liquid brine residual to a collection bag. This evaporator is meant to be lightweight, which allows it to be discarded along with the accumulated brine solids contained within it. This paper discusses design and development of a first CoBRA prototype, and reports

  3. High-temperature-measuring device

    DOEpatents

    Not Available

    1981-01-27

    A temperature measuring device for very high design temperatures (to 2000/sup 0/C) is described. The device comprises a homogenous base structure preferably in the form of a sphere or cylinder. The base structure contains a large number of individual walled cells. The base structure has a decreasing coefficient of elasticity within the temperature range being monitored. A predetermined quantity of inert gas is confined within each cell. The cells are dimensonally stable at the normal working temperature of the device. Increases in gaseous pressure within the cells will permanently deform the cell walls at temperatures within the high temperature range to be measured. Such deformation can be correlated to temperature by calibrating similarly constructed devices under known time and temperature conditions.

  4. High temperature interface superconductivity

    DOE PAGESBeta

    Gozar, A.; Bozovic, I.

    2016-01-20

    High-Tc superconductivity at interfaces has a history of more than a couple of decades. In this review we focus our attention on copper-oxide based heterostructures and multi-layers. We first discuss the technique, atomic layer-by-layer molecular beam epitaxy (ALL-MBE) engineering, that enabled High-Tc Interface Superconductivity (HT-IS), and the challenges associated with the realization of high quality interfaces. Then we turn our attention to the experiments which shed light on the structure and properties of interfacial layers, allowing comparison to those of single-phase films and bulk crystals. Both ‘passive’ hetero-structures as well as surface-induced effects by external gating are discussed. Here, wemore » conclude by comparing HT-IS in cuprates and in other classes of materials, especially Fe-based superconductors, and by examining the grand challenges currently laying ahead for the field.« less

  5. High temperature interface superconductivity

    NASA Astrophysics Data System (ADS)

    Gozar, A.; Bozovic, I.

    2016-02-01

    High-Tc superconductivity at interfaces has a history of more than a couple of decades. In this review we focus our attention on copper-oxide based heterostructures and multi-layers. We first discuss the technique, atomic layer-by-layer molecular beam epitaxy (ALL-MBE) engineering, that enabled High-Tc Interface Superconductivity (HT-IS), and the challenges associated with the realization of high quality interfaces. Then we turn our attention to the experiments which shed light on the structure and properties of interfacial layers, allowing comparison to those of single-phase films and bulk crystals. Both 'passive' hetero-structures as well as surface-induced effects by external gating are discussed. We conclude by comparing HT-IS in cuprates and in other classes of materials, especially Fe-based superconductors, and by examining the grand challenges currently laying ahead for the field.

  6. High-temperature ceramic receivers

    SciTech Connect

    Jarvinen, P. O.

    1980-01-01

    An advanced ceramic dome cavity receiver is discussed which heats pressurized gas to temperatures above 1800/sup 0/F (1000/sup 0/C) for use in solar Brayton power systems of the dispersed receiver/dish or central receiver type. Optical, heat transfer, structural, and ceramic material design aspects of the receiver are reported and the development and experimental demonstration of a high-temperature seal between the pressurized gas and the high-temperature silicon carbide dome material is described.

  7. Experimental multi-phase H2O-CO2 brine interactions at elevated temperature and pressure: Implications for CO2 sequestration in deep-saline aquifers

    USGS Publications Warehouse

    Rosenbauer, R.; Koksalan, T.

    2004-01-01

    The burning of fossil fuel and other anthropogenic activities have caused a continuous and dramatic 30% increase of atmospheric CO2 over the past 150 yr. CO2 sequestration is increasingly being viewed as a tool for managing these anthropogenic CO2 emissions to the atmosphere. CO2-saturated brine-rock experiments were carried out to evaluate the effects of multiphase H2O-CO2 fluids on mineral equilibria and the potential for CO2 sequestration in mineral phases within deep-saline aquifers. Experimental results were generally consistent with theoretical thermodynamic calculations. The solubility of CO2 was enhanced in brines in the presence of both limestone and sandstone relative to brines alone. Reactions between CO2 saturated brines and arkosic sandstones were characterized by desiccation of the brine and changes in the chemical composition of the brine suggesting fixation of CO2 in mineral phases. These reactions were occurring on a measurable but kinetically slow time scale at 120??C.

  8. High Temperature Solar Cell Development

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Raffaelle, Ryne P.; Merritt, Danielle

    2004-01-01

    The majority of satellites and near-earth probes developed to date have used photovoltaic arrays for power generation. If future mission to probe environments close to the sun will be able to use photovoltaic power, solar cells that can function at high temperatures, under high light intensity, and high radiation conditions must be developed. In this paper, we derive the optimum bandgap as a function of the operating temperature.

  9. Bacterial responses to fluctuations and extremes in temperature and brine salinity at the surface of Arctic winter sea ice.

    PubMed

    Ewert, Marcela; Deming, Jody W

    2014-08-01

    Wintertime measurements near Barrow, Alaska, showed that bacteria near the surface of first-year sea ice and in overlying saline snow experience more extreme temperatures and salinities, and wider fluctuations in both parameters, than bacteria deeper in the ice. To examine impacts of such conditions on bacterial survival, two Arctic isolates with different environmental tolerances were subjected to winter-freezing conditions, with and without the presence of organic solutes involved in osmoprotection: proline, choline, or glycine betaine. Obligate psychrophile Colwellia psychrerythraea strain 34H suffered cell losses under all treatments, with maximal loss after 15-day exposure to temperatures fluctuating between -7 and -25 °C. Osmoprotectants significantly reduced the losses, implying that salinity rather than temperature extremes presents the greater stress for this organism. In contrast, psychrotolerant Psychrobacter sp. strain 7E underwent miniaturization and fragmentation under both fluctuating and stable-freezing conditions, with cell numbers increasing in most cases, implying a different survival strategy that may include enhanced dispersal. Thus, the composition and abundance of the bacterial community that survives in winter sea ice may depend on the extent to which overlying snow buffers against extreme temperature and salinity conditions and on the availability of solutes that mitigate osmotic shock, especially during melting.

  10. The formation of supercooled brines, viscous liquids, and low-temperature perchlorate glasses in aqueous solutions relevant to Mars

    NASA Astrophysics Data System (ADS)

    Toner, J. D.; Catling, D. C.; Light, B.

    2014-05-01

    Salt solutions on Mars can stabilize liquid water at low temperatures by lowering the freezing point of water. The maximum equilibrium freezing-point depression possible, known as the eutectic temperature, suggests a lower temperature limit for liquid water on Mars; however, salt solutions can supercool below their eutectic before crystallization occurs. To investigate the magnitude of supercooling and its variation with salt composition and concentration, we performed slow cooling and warming experiments on pure salt solutions and saturated soil-solutions of MgSO4, MgCl2, NaCl, NaClO4, Mg(ClO4)2, and Ca(ClO4)2. By monitoring solution temperatures, we identified exothermic crystallization events and determined the composition of precipitated phases from the eutectic melting temperature. Our results indicate that supercooling is pervasive. In general, supercooling is greater in more concentrated solutions and with salts of Ca and Mg. Slowly cooled MgSO4, MgCl2, NaCl, and NaClO4 solutions investigated in this study typically supercool 5-15 °C below their eutectic temperature before crystallizing. The addition of soil to these salt solutions has a variable effect on supercooling. Relative to the pure salt solutions, supercooling decreases in MgSO4 soil-solutions, increases in MgCl2 soil-solutions, and is similar in NaCl and NaClO4 soil-solutions. Supercooling in MgSO4, MgCl2, NaCl, and NaClO4 solutions could marginally extend the duration of liquid water during relatively warm daytime temperatures in the martian summer. In contrast, we find that Mg(ClO4)2 and Ca(ClO4)2 solutions do not crystallize during slow cooling, but remain in a supercooled, liquid state until forming an amorphous glass near -120 °C. Even if soil is added to the solutions, a glass still forms during cooling. The large supercooling effect in Mg(ClO4)2 and Ca(ClO4)2 solutions has the potential to prevent water from freezing over diurnal and possibly annual cycles on Mars. Glasses are also

  11. Waste glass/metal interactions in brines

    SciTech Connect

    Shade, J.W.; Pederson, L.R.; McVay, G.L.

    1983-05-01

    Leaching studies of MCC 76-68 glass in synthetic brines high in NaCl were performed from 50 to 150/sup 0/C and included interactive testing with ductile iron and titanium. Hydrolysis of the glass matrix was generally slower in saturated brines than in deionized water, due to a lower solubility of silica in the brines. Inclusion of ductile iron in the tests resulted in accelerated leach rates because irion-silica reactions occurred which reduced the silica saturation fraction. At 150/sup 0/C, iron also accelerated the rate of crystalline reaction product formation which were primarily Fe-bearing sepiolite and talc. 16 references.

  12. Particle measurement and brine chemistry at the Salton Sea Deep Well

    NASA Astrophysics Data System (ADS)

    Robertus, R. J.; Kindle, C. H.; Sullivan, R. G.; Shannon, D. W.

    1991-09-01

    The Advanced Brine Chemistry Project, a part of the U.S. Department of Energy's Geothermal Energy Program, is addressing operating problems associated with scaling and corrosion at geothermal power plants. Under this project, Pacific Northwest Laboratory conducted a series of tests at the Salton Sea Deep Well, which has one of the highest solids contents in the world. The purpose of the tests was to evaluate monitoring instrumentation under field conditions and relate particulate formation to the brine chemistry. The instrumentation, was evaluated under scaling geothermal conditions using two different principles: ultrasonic reflection and laser light scattering. The following conclusions were drawn from the instrumentation testing and brine chemistry and particulate analyses. (1) Using reflected ultrasonic impulses to detect suspended particles has been demonstrated for on-line application in a geothermal brine with strong scaling tendencies. Advantages over laser light scattering include improved high-temperature durability for the transducer and longer operation with less maintenance. (2) Counting and sizing particles using laser light scattering requires constant maintenance in geothermal applications. (3) Silica is the dominant scale species and appears in amounts orders of magnitude greater than other minor species such as barium sulfate. (4) The silica that formed at high temperatures and short residence times is very gelatinous and difficult to filter out of the brine. (5) Correlation of instrument readings with particle collection data was difficult because conditions on the filter (i.e., temperature, flowrate, and pressure) could not be maintained constant for long enough intervals to obtain comparable information.

  13. Advanced High Temperature Structural Seals

    NASA Astrophysics Data System (ADS)

    Newquist, Charles W.; Verzemnieks, Juris; Keller, Peter C.; Rorabaugh, Michael; Shorey, Mark

    2002-10-01

    This program addresses the development of high temperature structural seals for control surfaces for a new generation of small reusable launch vehicles. Successful development will contribute significantly to the mission goal of reducing launch cost for small, 200 to 300 pound payloads. Development of high temperature seals is mission enabling. For instance, ineffective control surface seals can result in high temperature (3100 F) flows in the elevon area exceeding structural material limits. Longer sealing life will allow use for many missions before replacement, contributing to the reduction of hardware, operation and launch costs.

  14. Advanced High Temperature Structural Seals

    NASA Technical Reports Server (NTRS)

    Newquist, Charles W.; Verzemnieks, Juris; Keller, Peter C.; Rorabaugh, Michael; Shorey, Mark

    2002-01-01

    This program addresses the development of high temperature structural seals for control surfaces for a new generation of small reusable launch vehicles. Successful development will contribute significantly to the mission goal of reducing launch cost for small, 200 to 300 pound payloads. Development of high temperature seals is mission enabling. For instance, ineffective control surface seals can result in high temperature (3100 F) flows in the elevon area exceeding structural material limits. Longer sealing life will allow use for many missions before replacement, contributing to the reduction of hardware, operation and launch costs.

  15. Development of high strength, high temperature ceramics

    NASA Technical Reports Server (NTRS)

    Hall, W. B.

    1982-01-01

    Improvement in the high-pressure turbopumps, both fuel and oxidizer, in the Space Shuttle main engine were considered. The operation of these pumps is limited by temperature restrictions of the metallic components used in these pumps. Ceramic materials that retain strength at high temperatures and appear to be promising candidates for use as turbine blades and impellers are discussed. These high strength materials are sensitive to many related processing parameters such as impurities, sintering aids, reaction aids, particle size, processing temperature, and post thermal treatment. The specific objectives of the study were to: (1) identify and define the processing parameters that affect the properties of Si3N4 ceramic materials, (2) design and assembly equipment required for processing high strength ceramics, (3) design and assemble test apparatus for evaluating the high temperature properties of Si3N4, and (4) conduct a research program of manufacturing and evaluating Si3N4 materials as applicable to rocket engine applications.

  16. Reactions of a prototype nuclear-waste ceramic with a hot magnesium-rich brine

    NASA Astrophysics Data System (ADS)

    Komarneni, S.; Scheetz, B. E.; Freeborn, W. P.; McCarthy, G. J.; White, W. B.

    1982-10-01

    Prototype ceramic nuclear waste forms were experimentally reacted with a high calcium and magnesium brine under hydrothermal conditions. The said reaction products and fluid were analyzed at the end of the experiment. Alteration of the waste forms was observed and the reaction products identified. Uptake of cesium, rubidium, strontium, barium, lanthanum and neodymium into the brine was measured with a strong temperature dependence, i.e., increased concentrations with increased temperature. The concentrations of the six elements also increased with time, and imply that dissolution of the ceramic is controlled by diffusion and/or crystalline dissolution mechanism.

  17. Results for the Brine Evaporation Bag (BEB) Brine Processing Test

    NASA Technical Reports Server (NTRS)

    Delzeit, Lance; Flynn, Michael; Fisher, John; Shaw, Hali; Kawashima, Brian; Beeler, David; Howard, Kevin

    2015-01-01

    The recent Brine Processing Test compared the NASA Forward Osmosis Brine Dewatering (FOBD), Paragon Ionomer Water Processor (IWP), UMPQUA Ultrasonic Brine Dewatering System (UBDS), and the NASA Brine Evaporation Bag (BEB). This paper reports the results of the BEB. The BEB was operated at 70 deg C and a base pressure of 12 torr. The BEB was operated in a batch mode, and processed 0.4L of brine per batch. Two different brine feeds were tested, a chromic acid-urine brine and a chromic acid-urine-hygiene mix brine. The chromic acid-urine brine, known as the ISS Alternate Pretreatment Brine, had an average processing rate of 95 mL/hr with a specific power of 5kWhr/L. The complete results of these tests will be reported within this paper.

  18. High temperature turbine engine structure

    DOEpatents

    Boyd, Gary L.

    1990-01-01

    A high temperature turbine engine includes a hybrid ceramic/metallic rotor member having ceramic/metal joint structure. The disclosed joint is able to endure higher temperatures than previously possible, and aids in controlling heat transfer in the rotor member.

  19. Advanced High Temperature Structural Seals

    NASA Technical Reports Server (NTRS)

    Newquist, Charles W.; Verzemnieks, Juris; Keller, Peter C.; Shorey, Mark W.; Steinetz, Bruce (Technical Monitor)

    2000-01-01

    This program addresses the development of high temperature structural seals for control surfaces for a new generation of small reusable launch vehicles. Successful development will contribute significantly to the mission goal of reducing launch cost for small, 200 to 300 lb payloads. Development of high temperature seals is mission enabling. For instance, ineffective control surface seals can result in high temperature (3100 F) flows in the elevon area exceeding structural material limits. Longer sealing life will allow use for many missions before replacement, contributing to the reduction of hardware, operation and launch costs. During the first phase of this program the existing launch vehicle control surface sealing concepts were reviewed, the aerothermal environment for a high temperature seal design was analyzed and a mock up of an arc-jet test fixture for evaluating seal concepts was fabricated.

  20. High temperature structural insulating material

    DOEpatents

    Chen, W.Y.

    1984-07-27

    A high temperature structural insulating material useful as a liner for cylinders of high temperature engines through the favorable combination of high service temperature (above about 800/sup 0/C), low thermal conductivity (below about 0.2 W/m/sup 0/C), and high compressive strength (above about 250 psi). The insulating material is produced by selecting hollow ceramic beads with a softening temperature above about 800/sup 0/C, a diameter within the range of 20-200 ..mu..m, and a wall thickness in the range of about 2 to 4 ..mu..m; compacting the beads and a compatible silicate binder composition under pressure and sintering conditions to provide the desired structural form with the structure having a closed-cell, compact array of bonded beads.

  1. High temperature structural insulating material

    DOEpatents

    Chen, Wayne Y.

    1987-01-01

    A high temperature structural insulating material useful as a liner for cylinders of high temperature engines through the favorable combination of high service temperature (above about 800.degree. C.), low thermal conductivity (below about 0.2 W/m.degree. C.), and high compressive strength (above about 250 psi). The insulating material is produced by selecting hollow ceramic beads with a softening temperature above about 800.degree. C., a diameter within the range of 20-200 .mu.m, and a wall thickness in the range of about 2-4 .mu.m; compacting the beads and a compatible silicate binder composition under pressure and sintering conditions to provide the desired structural form with the structure having a closed-cell, compact array of bonded beads.

  2. High temperature structural insulating material

    DOEpatents

    Chen, Wayne Y.

    1987-01-06

    A high temperature structural insulating material useful as a liner for cylinders of high temperature engines through the favorable combination of high service temperature (above about 800.degree. C.), low thermal conductivity (below about 0.2 W/m.degree. C.), and high compressive strength (above about 250 psi). The insulating material is produced by selecting hollow ceramic beads with a softening temperature above about 800.degree. C., a diameter within the range of 20-200 .mu.m, and a wall thickness in the range of about 2-4 .mu.m; compacting the beads and a compatible silicate binder composition under pressure and sintering conditions to provide the desired structural form with the structure having a closed-cell, compact array of bonded beads.

  3. Containerless high temperature calorimeter apparatus

    NASA Technical Reports Server (NTRS)

    Lacy, L. L.; Nisen, D. B. (Inventor)

    1981-01-01

    A calorimeter apparatus for measuring high temperature thermophysical properties of materials is disclosed which includes a containerless heating apparatus in which the specimen is suspended and heated by electron bombardment.

  4. High-temperature structural intermetallics

    SciTech Connect

    Yamaguchi, M.; Inui, H.; Ito, K.

    2000-01-01

    In the last one and a half decades, a great deal of fundamental and developmental research has been made on high-temperature structural intermetallics aiming at the implementation of these intermetallics in aerospace, automotive and land-based applications. These intermetallics include aluminides formed with either titanium, nickel or iron and silicides formed with transition metals. Of these high-temperature intermetallics, TiAl-based alloys with great potential in both aerospace and automotive applications have been attracting particular attention. Recently TiAl turbocharger wheels have finally started being used for turbochargers for commercial passenger cars of a special type. The current status of the research and development of these high-temperature intermetallics is summarized and a perspective on what directions future research and development of high-temperature intermetallics should take is provided.

  5. High temperature current mirror amplifier

    DOEpatents

    Patterson, III, Raymond B.

    1984-05-22

    A high temperature current mirror amplifier having biasing means in the transdiode connection of the input transistor for producing a voltage to maintain the base-collector junction reversed-biased and a current means for maintaining a current through the biasing means at high temperatures so that the base-collector junction of the input transistor remained reversed-biased. For accuracy, a second current mirror is provided with a biasing means and current means on the input leg.

  6. Thermal-gradient migration of brine inclusions in salt crystals. [Synthetic single crystals of NaCl and KCl

    SciTech Connect

    Yagnik, S.K.

    1982-09-01

    It has been proposed that high-level nuclear waste be disposed in a geologic repository. Natural-salt deposits, which are being considered for this purpose, contain a small volume fraction of water in the form of brine inclusions distributed throughout the salt. Radioactive-decay heating of the nuclear wastes will impose a temperature gradient on the surrounding salt which mobilizes the brine inclusions. Inclusions filled completely with brine migrate up the temperature gradient and eventually accumulate brine near the buried waste forms. The brine may slowly corrode or degrade the waste forms which is undesirable. In this work, thermal gradient migration of both all-liquid and gas-liquid inclusions was experimentally studied in synthetic single crystals of NaCl and KCl using a hot-stage attachment to an optical microscope which was capable of imposing temperature gradients and axial compressive loads on the crystals. The migration velocities of the inclusions were found to be dependent on temperature, temperature gradient, and inclusion shape and size. The velocities were also dictated by the interfacial mass transfer resistance at brine/solid interface. This interfacial resistance depends on the dislocation density in the crystal, which in turn, depends on the axial compressive loading of the crystal. At low axial loads, the dependence between the velocity and temperature gradient is non-linear.At high axial loads, however, the interfacial resistance is reduced and the migration velocity depends linearly on the temperature gradient. All-liquid inclusions filled with mixed brines were also studied. For gas-liquid inclusions, three different gas phases (helium, air and argon) were compared. Migration studies were also conducted on single crystallites of natural salt as well as in polycrystalline natural salt samples. The behavior of the inclusions at large angle grain boundaries was observed. 35 figures, 3 tables.

  7. The Very High Temperature Reactor

    SciTech Connect

    Hans D. Gougar; David A. Petti

    2011-06-01

    The High Temperature Reactor (HTR) and Very High Temperature Reactor (VHTR) are types of nuclear power plants that, as the names imply, operate at temperatures above those of the conventional nuclear power plants that currently generate electricity in the US and other countries. Like existing nuclear plants, heat generated from the fission of uranium or plutonium atoms is carried off by a working fluid and can be used generate electricity. The very hot working fluid also enables the VHTR to drive other industrial processes that require high temperatures not achievable by conventional nuclear plants (Figure 1). For this reason, the VHTR is being considered for non-electrical energy applications. The reactor and power conversion system are constructed using special materials that make a core meltdown virtually impossible.

  8. Formate brines for drilling and completion: State of the art

    SciTech Connect

    Howard, S.K.

    1995-12-31

    Low solids drilling fluids based on formate brines (sodium, potassium and caesium salts of formic acid) were originally designed to minimise frictional pressure losses in slim hole drilling applications. In addition, their unique capability of stabilising polymers to high temperatures made them more temperature resistant than any other polymer based drilling fluids. Subsequent work has shown that these brines, because of their high densities and low corrosivity, are also ideal completion and packer fluids. Formate brines have excellent HSE profiles and they are compatible with reservoir fluids, good shale stabilisers, gas hydrate inhibitors, and scale dissolvers. Also, a technique has been found for cost effective clean-up and recycling of formate based drilling fluids. The commercialisation and introduction of these fluids into the field (especially caesium formate) has taken a long time, due to high prices and few manufacturers. This situation is now changing, as the number of manufacturers is increasing, and buy-back arrangements have been made available. Also, a number of successful drilling and completion trials have been carried out.

  9. Temperature controlled high voltage regulator

    DOEpatents

    Chiaro, Jr., Peter J.; Schulze, Gerald K.

    2004-04-20

    A temperature controlled high voltage regulator for automatically adjusting the high voltage applied to a radiation detector is described. The regulator is a solid state device that is independent of the attached radiation detector, enabling the regulator to be used by various models of radiation detectors, such as gas flow proportional radiation detectors.

  10. High temperature electronic gain device

    DOEpatents

    McCormick, J. Byron; Depp, Steven W.; Hamilton, Douglas J.; Kerwin, William J.

    1979-01-01

    An integrated thermionic device suitable for use in high temperature, high radiation environments. Cathode and control electrodes are deposited on a first substrate facing an anode on a second substrate. The substrates are sealed to a refractory wall and evacuated to form an integrated triode vacuum tube.

  11. High temperature lightweight foamed cements

    DOEpatents

    Sugama, Toshifumi.

    1989-10-03

    Cement slurries are disclosed which are suitable for use in geothermal wells since they can withstand high temperatures and high pressures. The formulation consists of cement, silica flour, water, a retarder, a foaming agent, a foam stabilizer, and a reinforcing agent. A process for producing these cements is also disclosed. 3 figs.

  12. High temperature lightweight foamed cements

    DOEpatents

    Sugama, Toshifumi

    1989-01-01

    Cement slurries are disclosed which are suitable for use in geothermal wells since they can withstand high temperatures and high pressures. The formulation consists of cement, silica flour, water, a retarder, a foaming agent, a foam stabilizer, and a reinforcing agent. A process for producing these cements is also disclosed.

  13. High temperature Seebeck coefficient metrology

    SciTech Connect

    Martin, J.; Tritt, T.; Uher, C.

    2010-12-15

    We present an overview of the challenges and practices of thermoelectric metrology on bulk materials at high temperature (300 to 1300 K). The Seebeck coefficient, when combined with thermal and electrical conductivity, is an essential property measurement for evaluating the potential performance of novel thermoelectric materials. However, there is some question as to which measurement technique(s) provides the most accurate determination of the Seebeck coefficient at high temperature. This has led to the implementation of nonideal practices that have further complicated the confirmation of reported high ZT materials. To ensure meaningful interlaboratory comparison of data, thermoelectric measurements must be reliable, accurate, and consistent. This article will summarize and compare the relevant measurement techniques and apparatus designs required to effectively manage uncertainty, while also providing a reference resource of previous advances in high temperature thermoelectric metrology.

  14. Gallium phosphide high temperature diodes

    NASA Technical Reports Server (NTRS)

    Chaffin, R. J.; Dawson, L. R.

    1981-01-01

    High temperature (300 C) diodes for geothermal and other energy applications were developed. A comparison of reverse leakage currents of Si, GaAs, and GaP was made. Diodes made from GaP should be usable to 500 C. A Liquid Phase Epitaxy (LPE) process for producing high quality, grown junction GaP diodes is described. This process uses low vapor pressure Mg as a dopant which allows multiple boat growth in the same LPE run. These LPE wafers were cut into die and metallized to make the diodes. These diodes produce leakage currents below ten to the -9th power A/sq cm at 400 C while exhibiting good high temperature rectification characteristics. High temperature life test data is presented which shows exceptional stability of the V-I characteristics.

  15. Temperature optimization of high con

    NASA Astrophysics Data System (ADS)

    Sabry, M.

    2016-06-01

    Active cooling is essential for solar cells operating under high optical concentration ratios. A system comprises four solar cells that are in thermal contact on top of a copper tube is proposed. Water is flowing inside the tube in order to reduce solar cells temperature for increasing their performance. Computational Fluid Dynamics (CFD) simulation of such system has been performed in order to investigate the effect of water flow rate, tube internal diameter, and convective heat transfer coefficient on the temperature of the solar cells. It is found that increasing convective heat transfer coefficient has a significant effect on reducing solar cells temperatures operating at low flow rates and high optical concentration ratios. Also, a further increase of water flow rate has no effect on reducing cells temperatures.

  16. Quantification of sub-resolution porosity in carbonate rocks by applying high-salinity contrast brine using X-ray microtomography differential imaging

    NASA Astrophysics Data System (ADS)

    Lin, Qingyang; Al-Khulaifi, Yousef; Blunt, Martin J.; Bijeljic, Branko

    2016-10-01

    Characterisation of the pore space in carbonate reservoirs and aquifers is of utmost importance in a number of applications such as enhanced oil recovery, geological carbon storage and contaminant transport. We present a new experimental methodology that uses high-salinity contrast brine and differential imaging acquired by X-ray tomography to non-invasively obtain three-dimensional spatially resolved information on porosity and connectivity of two rock samples, Portland and Estaillades limestones, including sub-resolution micro-porosity. We demonstrate that by injecting 30 wt% KI brine solution, a sufficiently high phase contrast can be achieved allowing accurate three-phase segmentation based on differential imaging. This results in spatially resolved maps of the solid grain phase, sub-resolution micro-pores within the grains, and macro-pores. The total porosity values from the three-phase segmentation for two carbonate rock samples are shown to be in good agreement with Helium porosity measurements. Furthermore, our flow-based method allows for an accurate estimate of pore connectivity and a distribution of porosity within the sub-resolution pores.

  17. Exchange of Na+ and K+ between water vapor and feldspar phases at high temperature and low vapor pressure

    USGS Publications Warehouse

    Fournier, R.O.

    1976-01-01

    In order to determine whether gas (steam) containing a small amount of dissolved alkali chloride is effective in promoting base exchange of Na+ and K+ among alkali feldspars and coexisting brine or brine plus solid salt, experiments were carried out at 400-700??C and steam densities ranging down to less than 0.05. For bulk compositions rich in potassium, the low pressure results are close to previous high-pressure results in composition of the fluid and coexisting solid phase. However, when the bulk composition is more sodic, alkali feldspars are relatively richer in potassium at low pressure than at high pressure. This behaviour corresponds to enrichment of potassium in the gas phase relative to coexisting brine and precipitation of solid NaCl when the brine plus gas composition becomes moderately sodic. The gas phase is very effective in promoting base exchange between coexisting alkali feldspars at high temperature and low water pressure. This suggests that those igneous rocks which contain coexisting alkali feldspars out of chemical equilibrium either remained very dry during the high-temperature part of their cooling history or that the pore fluid was a gas containing very little potassium relative to sodium. ?? 1976.

  18. Containerless high-temperature calorimeter

    NASA Technical Reports Server (NTRS)

    Lacy, L. L.; Nisen, D. B.; Robinson, M. B.

    1979-01-01

    Samples are heated by electron bombardment in high-temperature calorimeter that operates from 1,000 to 3,600 C yet consumes less that 100 watts at temperatures less than 2,500 C. Contamination of samples is kept to minimum by suspending them from wire in vacuum chamber. Various sample slopes such as wires, dishs, spheres, rods, or irregular bodies can be accommodated and only about 100 nq of samples are needed for accurate measurements.

  19. Bellows high temperature cycle life

    SciTech Connect

    Broyles, R.K.

    1995-11-01

    In most cases, the bellows elements in an expansion joint are separated or insulated from the hot flow stream and have an actual bellows metal temperature (ABMT) that is much lower than the flow stream temperature. However, when the bellows are externally insulated or when the expansion joint is located inside a hot vessel, the ABMT can be very high. For these situations, the effects of temperature on bellows cycle life should be carefully considered. The design equations presented in the Standards of the expansion Joint Manufacturers Association (EJMA), ASME Section 8, Division 1, and ASME B31.3 do not currently provide cycle life equations or temperature correction factors for bellows operating in the creep temperature range. Therefore, a method is proposed which is specifically tailored to bellows for the estimation of high temperature cycle life based upon available test results. Data is also presented which demonstrates the effect of temperatures above and below 800 F on the cycle life of various bellows materials.

  20. Numerical analysis of seawater circulation in carbonate platforms: II. The dynamic interaction between geothermal and brine reflux circulation

    USGS Publications Warehouse

    Jones, G.D.; Whitaker, F.F.; Smart, P.L.; Sanford, W.E.

    2004-01-01

    Density-driven seawater circulation may occur in carbonate platforms due to geothermal heating and / or reflux of water of elevated salinity. In geothermal circulation lateral contrasts in temperature between seawater and platform groundwaters warmed by the geothermal heat flux result in upward convective flow, with colder seawater drawn into the platform at depth. With reflux circulation, platform-top waters concentrated by evaporation flow downward, displacing less dense underlying groundwaters. We have used a variable density groundwater flow model to examine the pattern, magnitude and interaction of these two different circulation mechanisms, for mesosaline platform-top waters (50???) and brines concentrated up to saturation with respect to gypsum (150???) and halite (246???). Geothermal circulation, most active around the platform margin, becomes restricted and eventually shut-off by reflux of brines from the platform interior towards the margin. The persistence of geothermal circulation is dependent on the rate of brine reflux, which is proportional to the concentration of platform-top brines and also critically dependent on the magnitude and distribution of permeability. Low permeability evaporites can severely restrict reflux whereas high permeability units in hydraulic continuity enhance brine transport. Reduction in permeability with depth and anisotropy of permeability (kv < < kh) focuses flow laterally in the shallow subsurface (<1 km), resulting in a horizontally elongated brine plume. Aquifer porosity and dispersivity are relatively minor controls on reflux. Platform brines can entrain surficial seawater when brine generating conditions cease but the platform-top remains submerged, a variant of reflux we term "latent reflux". Brines concentrated up to gypsum saturation have relatively long residence times of at least 100 times the duration of the reflux event. They thus represent a long-term control on post-reflux groundwater circulation, and

  1. OUT Success Stories: Chemical Treatments for Geothermal Brines

    SciTech Connect

    Burr, R.

    2000-08-31

    DOE research helped develop the large, untapped geothermal resource beneath the Salton Sea in California's Imperial Valley. The very hot brines under high pressure make them excellent for electric power production. The brines are very corrosive and contain high concentrations of dissolved silica. DOE worked with San Diego Gas and Electric Company to find a solution to the silica-scaling problem. This innovative brine treatment eliminated scaling and made possible the development of the Salton Sea geothermal resource.

  2. High Temperature Transparent Furnace Development

    NASA Technical Reports Server (NTRS)

    Bates, Stephen C.

    1997-01-01

    This report describes the use of novel techniques for heat containment that could be used to build a high temperature transparent furnace. The primary objective of the work was to experimentally demonstrate transparent furnace operation at 1200 C. Secondary objectives were to understand furnace operation and furnace component specification to enable the design and construction of a low power prototype furnace for delivery to NASA in a follow-up project. The basic approach of the research was to couple high temperature component design with simple concept demonstration experiments that modify a commercially available transparent furnace rated at lower temperature. A detailed energy balance of the operating transparent furnace was performed, calculating heat losses through the furnace components as a result of conduction, radiation, and convection. The transparent furnace shells and furnace components were redesigned to permit furnace operation at at least 1200 C. Techniques were developed that are expected to lead to significantly improved heat containment compared with current transparent furnaces. The design of a thermal profile in a multizone high temperature transparent furnace design was also addressed. Experiments were performed to verify the energy balance analysis, to demonstrate some of the major furnace improvement techniques developed, and to demonstrate the overall feasibility of a high temperature transparent furnace. The important objective of the research was achieved: to demonstrate the feasibility of operating a transparent furnace at 1200 C.

  3. High-Temperature Optical Sensor

    NASA Technical Reports Server (NTRS)

    Adamovsky, Grigory; Juergens, Jeffrey R.; Varga, Donald J.; Floyd, Bertram M.

    2010-01-01

    A high-temperature optical sensor (see Figure 1) has been developed that can operate at temperatures up to 1,000 C. The sensor development process consists of two parts: packaging of a fiber Bragg grating into a housing that allows a more sturdy thermally stable device, and a technological process to which the device is subjected to in order to meet environmental requirements of several hundred C. This technology uses a newly discovered phenomenon of the formation of thermally stable secondary Bragg gratings in communication-grade fibers at high temperatures to construct robust, optical, high-temperature sensors. Testing and performance evaluation (see Figure 2) of packaged sensors demonstrated operability of the devices at 1,000 C for several hundred hours, and during numerous thermal cycling from 400 to 800 C with different heating rates. The technology significantly extends applicability of optical sensors to high-temperature environments including ground testing of engines, flight propulsion control, thermal protection monitoring of launch vehicles, etc. It may also find applications in such non-aerospace arenas as monitoring of nuclear reactors, furnaces, chemical processes, and other hightemperature environments where other measurement techniques are either unreliable, dangerous, undesirable, or unavailable.

  4. Supercooling and Ice Formation of Perchlorate Brines under Mars-relevant Conditions

    NASA Astrophysics Data System (ADS)

    Primm, K.; Gough, R. V.; Tolbert, M. A.

    2015-12-01

    Perchlorate salts, discovered in the Martian regolith at multiple landing sites, may provide pathways for liquid water stability on current Mars. It has previously been assumed that if perchlorate brines form in the Martian regolith via melting or deliquescence, they would be present only briefly because efflorescence into a crystal or freezing to ice would soon occur. Here, we used a Raman microscope to study the temperature and relative humidity (RH) conditions at which magnesium perchlorate brine will form ice. Although ice is thermodynamically predicted to form whenever the saturation with respect to ice (Sice) is greater than or equal to 1, ice formation by perchlorate brines did not occur until elevated Sice values were reached: Sice= 1.17, 1.29, and 1.25 at temperatures of 218 K, 230.5 K, and 244 K, respectively. If a magnesium perchlorate particle was allowed to deliquesce completely prior to experiencing ice supersaturation, the extent of supercooling was increased even further. These high supersaturation values imply perchlorate brines can exist over a wider range of conditions than previously believed. From these experiments it has been found that magnesium perchlorate exhibits supercooling well into the previous theoretical ice region of the stability diagram and that liquid brines on Mars could potentially exist for up to two additional hours per sol. This supercooling of magnesium perchlorate will help with the exploration of Mars by the Mars 2020 spacecraft by helping to understand the phase and duration of water existing in the Martian subsurface.

  5. High temperature current mirror amplifier

    DOEpatents

    Patterson, R.B. III.

    1984-05-22

    Disclosed is a high temperature current mirror amplifier having biasing means in the transdiode connection of the input transistor for producing a voltage to maintain the base-collector junction reversed-biased and a current means for maintaining a current through the biasing means at high temperatures so that the base-collector junction of the input transistor remained reversed-biased. For accuracy, a second current mirror is provided with a biasing means and current means on the input leg. 2 figs.

  6. "Green" High-Temperature Polymers

    NASA Technical Reports Server (NTRS)

    Meador, Michael A.

    1998-01-01

    PMR-15 is a processable, high-temperature polymer developed at the NASA Lewis Research Center in the 1970's principally for aeropropulsion applications. Use of fiber-reinforced polymer matrix composites in these applications can lead to substantial weight savings, thereby leading to improved fuel economy, increased passenger and payload capacity, and better maneuverability. PMR-15 is used fairly extensively in military and commercial aircraft engines components seeing service temperatures as high as 500 F (260 C), such as the outer bypass duct for the F-404 engine. The current world-wide market for PMR-15 materials (resins, adhesives, and composites) is on the order of $6 to 10 million annually.

  7. High Temperature Polymer Matrix Composites

    NASA Technical Reports Server (NTRS)

    1985-01-01

    These are the proceedings of the High Temperature Polymer Matrix Composites Conference held at the NASA Lewis Research Center on March 16 to 18, 1983. The purpose of the conference is to provide scientists and engineers working in the field of high temperature polymer matrix composites an opportunity to review, exchange, and assess the latest developments in this rapidly expanding area of materials technology. Technical papers are presented in the following areas: (1) matrix development; (2) adhesive development; (3) characterization; (4) environmental effects; and (5) applications.

  8. High temperature superconductor current leads

    DOEpatents

    Hull, J.R.; Poeppel, R.B.

    1995-06-20

    An electrical lead is disclosed having one end for connection to an apparatus in a cryogenic environment and the other end for connection to an apparatus outside the cryogenic environment. The electrical lead includes a high temperature superconductor wire and an electrically conductive material distributed therein, where the conductive material is present at the one end of the lead at a concentration in the range of from 0 to about 3% by volume, and at the other end of the lead at a concentration of less than about 20% by volume. Various embodiments are shown for groups of high temperature superconductor wires and sheaths. 9 figs.

  9. High temperature superconductor current leads

    DOEpatents

    Hull, John R.; Poeppel, Roger B.

    1995-01-01

    An electrical lead having one end for connection to an apparatus in a cryogenic environment and the other end for connection to an apparatus outside the cryogenic environment. The electrical lead includes a high temperature superconductor wire and an electrically conductive material distributed therein, where the conductive material is present at the one end of the lead at a concentration in the range of from 0 to about 3% by volume, and at the other end of the lead at a concentration of less than about 20% by volume. Various embodiments are shown for groups of high temperature superconductor wires and sheaths.

  10. Parameterization of and Brine Storage in MOR Hydrothermal Systems

    NASA Astrophysics Data System (ADS)

    Hoover, J.; Lowell, R. P.; Cummings, K. B.

    2009-12-01

    Single-pass parameterized models of high-temperature hydrothermal systems at oceanic spreading centers use observational constraints such as vent temperature, heat output, vent field area, and the area of heat extraction from the sub-axial magma chamber to deduce fundamental hydrothermal parameters such as total mass flux Q, bulk permeability k, and the thickness of the conductive boundary layer at the base of the system, δ. Of the more than 300 known systems, constraining data are available for less than 10%. Here we use the single pass model to estimate Q, k, and δ for all the seafloor hydrothermal systems for which the constraining data are available. Mean values of Q, k, and δ are 170 kg/s, 5.0x10-13 m2, and 20 m, respectively; which is similar to results obtained from the generic model. There is no apparent correlation with spreading rate. Using observed vent field lifetimes, the rate of magma replenishment can also be calculated. Essentially all high-temperature hydrothermal systems at oceanic spreading centers undergo phase separation, yielding a low chlorinity vapor and a high salinity brine. Some systems such as the Main Endeavour Field on the Juan de Fuca Ridge and the 9°50’N sites on the East Pacific Rise vent low chlorinity vapor for many years, while the high density brine remains sequestered beneath the seafloor. In an attempt to further understand the brine storage at the EPR, we used the mass flux Q determined above, time series of vent salinity and temperature, and the depth of the magma chamber to determine the rate of brine production at depth. We found thicknesses ranging from 0.32 meters to ~57 meters over a 1 km2 area from 1994-2002. These calculations suggest that brine maybe being stored within the conductive boundary layer without a need for lateral transport or removal by other means. We plan to use the numerical code FISHES to further test this idea.

  11. A solar high temperature kiln

    NASA Astrophysics Data System (ADS)

    Huettenhoelscher, N.; Bergmann, K.

    1981-11-01

    The feasibility of using solar energy in developing countries for baking ceramic construction materials was investigated. The solar high temperature kiln is described. It uses two parabolic concentrators which direct available radiation into the baking chamber. The Sun tracker has only one axis. Preliminary test results with the prototype kiln were satisfactory.

  12. High temperature turbine engine structure

    DOEpatents

    Boyd, Gary L.

    1991-01-01

    A high temperature turbine engine includes a rotor portion having axially stacked adjacent ceramic rotor parts. A ceramic/ceramic joint structure transmits torque between the rotor parts while maintaining coaxial alignment and axially spaced mutually parallel relation thereof despite thermal and centrifugal cycling.

  13. High-Temperature Vibration Damper

    NASA Technical Reports Server (NTRS)

    Clarke, Alan; Litwin, Joel; Krauss, Harold

    1987-01-01

    Device for damping vibrations functions at temperatures up to 400 degrees F. Dampens vibrational torque loads as high as 1,000 lb-in. but compact enough to be part of helicopter rotor hub. Rotary damper absorbs energy from vibrating rod, dissipating it in turbulent motion of viscous hydraulic fluid forced by moving vanes through small orifices.

  14. Aromatic hydrocarbons associated with brines from geopressured wells

    SciTech Connect

    Keeley, D.F.; Meriwether, J.R.

    1991-01-01

    The measurement of the basic physical chemical properties of the components of brine produced in the US DOE geopressured wells is necessary to provide the fundamental data necessary for understanding the mechanisms by which constituents of petroleum migrate and are partitioned into different phases in various geologic strata. The cryocondensate materials, which we sample, are present in the geopressured brines of all the wells observed to date. These materials are a complex mixture of aromatic compounds ranging in complexity from benzene to highly substituted anthracenes. While data is available for room temperature and for solutions of pure water, there is little earlier information on these compounds in solutions of higher salinity and at elevated temperatures. Our work extended the basic solubility data for benzene and toluene (two of the major aromatic constituents of the geopressured brine) to higher sodium chloride concentrations. The techniques we have developed during the course of this work allows us to make solubility measurements with precision and to make major contributions to the basic literature. It is important to realize that reliable data on these fundamental quantities comes only with great attention to detail and an insistence on consistency and reproducibility. To determine the solubility of one compound at one set of conditions requires the manual injection of a minimum of 45 samples into a gas chromatograph and an analysis of each chromatogram. 10 figs., 10 tabs.

  15. Pressure-driven brine migration in a salt repository

    SciTech Connect

    Hwang, Y.; Chambre, P.L.; Pigford, T.H.; Lee, W.W.L.

    1989-01-01

    The traditional view is that salt is the ideal rock for isolation of nuclear waste because it is ''dry'' and probably ''impermeable.'' The existence of salt through geologic time is prima facie evidence of such properties. Experiments and experience at potential salt sites for geologic repositories have indicated that while porosity and permeability of salt are low, the salt may be saturated with brine. If this hypothesis is correct, then it is possible to have brine flow due to pressure differences within the salt. If there is pressure-driven brine migration in salt repositories then it is paramount to know the magnitude of such flow because inward brine flow would affect the corrosion rate of nuclear waste containers and outward brine flow might affect radionuclide transport rates. Brine exists in natural salt as inclusions in salt crystals and in grain boundaries. Brine inclusions in crystals move to nearby grain boundaries when subjected to a temperature gradient, because of temperature-dependent solubility of salt. Brine in grain boundaries moves under the influence of a pressure gradient. When salt is mined to create a waste repository, brine from grain boundaries will migrate into the rooms, tunnels and boreholes because these cavities are at atmospheric pressure. After a heat-emitting waste package is emplaced and backfilled, the heat will impose a temperature gradient in the surrounding salt that will cause inclusions in the nearby salt to migrate to grain boundaries within a few years, adding to the brine that was already present in the grain boundaries. The formulation of brine movement with salt as a thermoelastic porous medium, in the context of the continuum theory of mixtures, has been described. In this report we show the mathematical details and discuss the results predicted by this analysis.

  16. High temperature, high power piezoelectric composite transducers.

    PubMed

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, Stewart

    2014-08-08

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined.

  17. High Temperature, High Power Piezoelectric Composite Transducers

    PubMed Central

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, StewarT.

    2014-01-01

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined. PMID:25111242

  18. High temperature, high power piezoelectric composite transducers.

    PubMed

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, Stewart

    2014-01-01

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined. PMID:25111242

  19. High-temperature containerless calorimeter

    NASA Technical Reports Server (NTRS)

    Robinson, M. B.; Lacy, L. L.

    1985-01-01

    A high-temperature (greater than 1500 K) containerless calorimeter is described and its usefulness demonstrated. The calorimeter uses the technique of omnidirectional electron bombardment of pendant drops to achieve an isothermal test environment. The small heat input into the sample (i.e., 15-50 W) can be controlled and measured. The apparatus can be used to determine the total hemispherical emissivity, specific heat, heat of fusion, surface tension, and equilibrium melting temperature of small molten drops in the temperature range of 1500 to 3500 K. The total hemispherical emissivity and specific heat of pure niobium and two alloys of niobium-germanium have been measured in the temperature range of 1700 to 2400 K. As reported in the literature, the total hemispherical emissivity varied as a function of temperature. However, specific heat values for both the pure metal and alloys seem to be independent of temperature. Specific heat for the liquid alloy phase was also measured and compared to the solid phase.

  20. Solute strengthening at high temperatures

    NASA Astrophysics Data System (ADS)

    Leyson, G. P. M.; Curtin, W. A.

    2016-08-01

    The high temperature behavior of solute strengthening has previously been treated approximately using various scaling arguments, resulting in logarithmic and power-law scalings for the stress-dependent energy barrier Δ E(τ ) versus stress τ. Here, a parameter-free solute strengthening model is extended to high temperatures/low stresses without any a priori assumptions on the functional form of Δ E(τ ) . The new model predicts that the well-established low-temperature, with energy barrier Δ {{E}\\text{b}} and zero temperature flow stress {τy0} , transitions to a near-logarithmic form for stresses in the regime 0.2<τ /{τy0}≤slant 0.5 and then transitions to a power-law form at even lower stresses τ /{τy0}<0.03 . Δ {{E}\\text{b}} and {τy0} remains as the reference energy and stress scales over the entire range of stresses. The model is applied to literature data on solution strengthening in Cu alloys and captures the experimental results quantitatively and qualitatively. Most importantly, the model accurately captures the transition in strength from the low-temperature to intermediate-temperature and the associated transition for the activation volume. Overall, the present analysis unifies the different qualitative models in the literature and, when coupled with the previous parameter-free solute strengthening model, provides a single predictive model for solute strengthening as a function of composition, temperature, and strain rate over the full range of practical utility.

  1. Solubility and Surface Adsorption Characteristics of Metal Oxides to High Temperature

    SciTech Connect

    D.J. Wesolowski; M.L. Machesky; S.E. Ziemniak; C. Xiao; D.A. Palmer; L.M. Anovitz; P. Benezeth

    2001-05-04

    The interaction of high temperature aqueous solutions with mineral surfaces plays a key role in many aspects of fossil, geothermal and nuclear energy production. This is an area of study in which the subsurface geochemical processes that determine brine composition, porosity and permeability changes, reservoir integrity, and fluid flow rates overlap with the industrial processes associated with corrosion of metal parts and deposition of solids in pipes and on heat exchanger surfaces. The sorption of ions on mineral surfaces is also of great interest in both the subsurface and ''above ground'' regimes of power production, playing a key role in subsurface migration of contaminants (nuclear waste disposal, geothermal brine re-injection, etc.) and in plant operations (corrosion mitigation, migration of radioactive metals from reactor core to heat exchanger, etc.). In this paper, results of the solubility and surface chemistry of metal oxides relevant to both regimes are summarized.

  2. High temperature strain gage evaluation

    NASA Technical Reports Server (NTRS)

    Gonzalez, J. I.

    1977-01-01

    The structural thermal test of an advanced ramjet missile section required strain measurements as high as 922 K (1200 F). Since there is relatively little experience in the use of strain gages above the 700-755 K (800-900 F) level, a program was initiated to select and evaluate the best available gage. Candidate gages suitable for measurements up to 922 K (1200 F) were selected. This involved the determination of their operating characteristics, availability, cost, installation aspects, etc. The evaluation involved the following tests: strain as a function of load at room temperature and apparent strain as a function of temperature.

  3. High temperature sorbents for oxygen

    NASA Technical Reports Server (NTRS)

    Sharma, Pramod K. (Inventor)

    1994-01-01

    A sorbent capable of removing trace amounts of oxygen (ppt) from a gas stream at a high temperature above 200 C comprising a porous alumina silicate support, such as zeolite, containing from 1 to 10 percent by weight of ion exchanged transition metal, such as copper or cobalt ions, and 0.05 to 1.0 percent by weight of an activator selected from a platinum group metal such as platinum is described. The activation temperature, oxygen sorption, and reducibility are all improved by the presence of the platinum activator.

  4. High Temperature Sorbents for Oxygen

    NASA Technical Reports Server (NTRS)

    Sharma, Pramod K. (Inventor)

    1996-01-01

    A sorbent capable of removing trace amounts of oxygen (ppt) from a gas stream at a high temperature above 200 C is introduced. The sorbent comprises a porous alumina silicate support such as zeolite containing from 1 to 10 percent by weight of ion exchanged transition metal such as copper or cobalt ions and 0.05 to 1.0 percent by weight of an activator selected from a platinum group metal such as platinum. The activation temperature, oxygen sorption and reducibility are all improved by the presence of the platinum activator.

  5. High temperature thermoelectric energy conversion

    NASA Technical Reports Server (NTRS)

    Wood, Charles

    1987-01-01

    The theory and current status of materials research for high-temperature thermoelectric energy conversion are reviewed. Semiconductors are shown to be the preferred class of materials for this application. Optimization of the figure of merit of both broadband and narrow-band semiconductors is discussed as a function of temperature. Phonon scattering mechanisms are discussed, and basic material guidelines are given for reduction of thermal conductivity. Two general classes of materials show promise for high temperature figure of merit (Z) values, namely the rare earth chalcogenides and the boron-rich borides. The electronic transport properties of the rare earth chalcogenides are explicable on the basis of degenerate or partially degenerate n-type semiconductors. Boron and boron-rich borides exhibit p-type hopping conductivity, with detailed explanations proposed for the transport differing from compound to compound. Some discussion is presented on the reasons for the low thermal conductivities in these materials. Also, ZTs greater than one appear to have been realized at high temperature in many of these compounds.

  6. High Temperature Transfer Molding Resins

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

    2000-01-01

    High temperature resins containing phenylethynyl groups that are processable by transfer molding have been prepared. These phenylethynyl containing oligomers were prepared from aromatic diamines containing phenylethynyl groups and various ratios of phthalic anhydride and 4-phenylethynlphthalic anhydride in glacial acetic acid to form a mixture of imide compounds in one step. This synthetic approach is advantageous since the products are a mixture of compounds and consequently exhibit a relatively low melting temperature. In addition, these materials exhibit low melt viscosities which are stable for several hours at 210-275 C, and since the thermal reaction of the phenylethynyl group does not occur to any appreciable extent at temperatures below 300 C, these materials have a broad processing window. Upon thermal cure at approximately 300-350 C, the phenylethynyl groups react to provide a crosslinked resin system. These new materials exhibit excellent properties and are potentially useful as adhesives, coatings, films, moldings and composite matrices.

  7. High temperature seal test rig

    NASA Technical Reports Server (NTRS)

    Addy, Harold E., Jr.

    1994-01-01

    The High Temperature Seals Test Rig Program at NASA's Lewis Research Center is a joint effort involving three separate federal government agencies. Testing has been underway at Lewis in this test rig since April, 1993. The rig was designed to run tests at temperatures to 800 F at pressures to 200 psia or at temperatures to 1300 to 1500 F at pressures to 65 psia. It was designed to run at speeds of up to 50,000 rpm which, for a 5.1 inch diameter disk, is a surface speed of about 1100 ft./sec. The rig was designed to allow easy replacement of the disks as well as the seals such that different disk materials and coatings may be tested.

  8. High-temperature battery calorimeter

    SciTech Connect

    Hansen, L.D.; Hart, R.H.; Chen, D.M.; Gibbard, H.F.

    1982-04-01

    A battery calorimeter was built for the measurement of thermal energy generation of high-temperature lithium--aluminum/iron sulfide battery cells, which are under development for electric vehicle propulsion and other energy storage applications. The calorimeter was designed with a temperature range of 400 /sup 0/--500 /sup 0/C, a detection limit of 1 mW, and an upper limit of heat flow of 50 W. The results of measurements on 200-Ah LiAl/FeS cells were in excellent agreement with the predictions of thermodynamic calculations based on precise measurements of the total cell polarization and the temperature coefficient of the emf. Details of the construction and operation principles of this calorimeter are given.

  9. Modeling acid-gas generation from boiling chloride brines

    PubMed Central

    2009-01-01

    Background This study investigates the generation of HCl and other acid gases from boiling calcium chloride dominated waters at atmospheric pressure, primarily using numerical modeling. The main focus of this investigation relates to the long-term geologic disposal of nuclear waste at Yucca Mountain, Nevada, where pore waters around waste-emplacement tunnels are expected to undergo boiling and evaporative concentration as a result of the heat released by spent nuclear fuel. Processes that are modeled include boiling of highly concentrated solutions, gas transport, and gas condensation accompanied by the dissociation of acid gases, causing low-pH condensate. Results Simple calculations are first carried out to evaluate condensate pH as a function of HCl gas fugacity and condensed water fraction for a vapor equilibrated with saturated calcium chloride brine at 50-150°C and 1 bar. The distillation of a calcium-chloride-dominated brine is then simulated with a reactive transport model using a brine composition representative of partially evaporated calcium-rich pore waters at Yucca Mountain. Results show a significant increase in boiling temperature from evaporative concentration, as well as low pH in condensates, particularly for dynamic systems where partial condensation takes place, which result in enrichment of HCl in condensates. These results are in qualitative agreement with experimental data from other studies. Conclusion The combination of reactive transport with multicomponent brine chemistry to study evaporation, boiling, and the potential for acid gas generation at the proposed Yucca Mountain repository is seen as an improvement relative to previously applied simpler batch evaporation models. This approach allows the evaluation of thermal, hydrological, and chemical (THC) processes in a coupled manner, and modeling of settings much more relevant to actual field conditions than the distillation experiment considered. The actual and modeled distillation

  10. Modeling acid-gas generation from boiling chloride brines

    SciTech Connect

    Zhang, Guoxiang; Spycher, Nicolas; Sonnenthal, Eric; Steefel, Carl

    2009-11-16

    This study investigates the generation of HCl and other acid gases from boiling calcium chloride dominated waters at atmospheric pressure, primarily using numerical modeling. The main focus of this investigation relates to the long-term geologic disposal of nuclear waste at Yucca Mountain, Nevada, where pore waters around waste-emplacement tunnels are expected to undergo boiling and evaporative concentration as a result of the heat released by spent nuclear fuel. Processes that are modeled include boiling of highly concentrated solutions, gas transport, and gas condensation accompanied by the dissociation of acid gases, causing low-pH condensate. Simple calculations are first carried out to evaluate condensate pH as a function of HCl gas fugacity and condensed water fraction for a vapor equilibrated with saturated calcium chloride brine at 50-150 C and 1 bar. The distillation of a calcium-chloride-dominated brine is then simulated with a reactive transport model using a brine composition representative of partially evaporated calcium-rich pore waters at Yucca Mountain. Results show a significant increase in boiling temperature from evaporative concentration, as well as low pH in condensates, particularly for dynamic systems where partial condensation takes place, which result in enrichment of HCl in condensates. These results are in qualitative agreement with experimental data from other studies. The combination of reactive transport with multicomponent brine chemistry to study evaporation, boiling, and the potential for acid gas generation at the proposed Yucca Mountain repository is seen as an improvement relative to previously applied simpler batch evaporation models. This approach allows the evaluation of thermal, hydrological, and chemical (THC) processes in a coupled manner, and modeling of settings much more relevant to actual field conditions than the distillation experiment considered. The actual and modeled distillation experiments do not represent

  11. NSTX High Temperature Sensor Systems

    SciTech Connect

    B.McCormack; H.W. Kugel; P. Goranson; R. Kaita; et al

    1999-11-01

    The design of the more than 300 in-vessel sensor systems for the National Spherical Torus Experiment (NSTX) has encountered several challenging fusion reactor diagnostic issues involving high temperatures and space constraints. This has resulted in unique miniature, high temperature in-vessel sensor systems mounted in small spaces behind plasma facing armor tiles, and they are prototypical of possible high power reactor first-wall applications. In the Center Stack, Divertor, Passive Plate, and vessel wall regions, the small magnetic sensors, large magnetic sensors, flux loops, Rogowski Coils, thermocouples, and Langmuir Probes are qualified for 600 degrees C operation. This rating will accommodate both peak rear-face graphite tile temperatures during operations and the 350 degrees C bake-out conditions. Similar sensor systems including flux loops, on other vacuum vessel regions are qualified for 350 degrees C operation. Cabling from the sensors embedded in the graphite tiles follows narrow routes to exit the vessel. The detailed sensor design and installation methods of these diagnostic systems developed for high-powered ST operation are discussed.

  12. Microbial life at -13 °C in the brine of an ice-sealed Antarctic lake

    NASA Astrophysics Data System (ADS)

    Murray, Alison E.; Kenig, Fabien; Fritsen, Christian H.; McKay, Christopher P.; Cawley, Kaelin M.; Edwards, Ross; Kuhn, Emanuele; McKnight, Diane M.; Ostrom, Nathaniel E.; Peng, Vivian; Ponce, Adrian; Priscu, John C.; Samarkin, Vladimir; Townsend, Ashley T.; Wagh, Protima; Young, Seth A.; Yung, Pung To; Doran, Peter T.

    2012-12-01

    The permanent ice cover of Lake Vida (Antarctica) encapsulates an extreme cryogenic brine ecosystem (-13 °C; salinity, 200). This aphotic ecosystem is anoxic and consists of a slightly acidic (pH 6.2) sodium chloride-dominated brine. Expeditions in 2005 and 2010 were conducted to investigate the biogeochemistry of Lake Vida's brine system. A phylogenetically diverse and metabolically active Bacteria dominated microbial assemblage was observed in the brine. These bacteria live under very high levels of reduced metals, ammonia, molecular hydrogen (H2), and dissolved organic carbon, as well as high concentrations of oxidized species of nitrogen (i.e., supersaturated nitrous oxide and ∼1 mmolṡL-1 nitrate) and sulfur (as sulfate). The existence of this system, with active biota, and a suite of reduced as well as oxidized compounds, is unusual given the millennial scale of its isolation from external sources of energy. The geochemistry of the brine suggests that abiotic brine-rock reactions may occur in this system and that the rich sources of dissolved electron acceptors prevent sulfate reduction and methanogenesis from being energetically favorable. The discovery of this ecosystem and the in situ biotic and abiotic processes occurring at low temperature provides a tractable system to study habitability of isolated terrestrial cryoenvironments (e.g., permafrost cryopegs and subglacial ecosystems), and is a potential analog for habitats on other icy worlds where water-rock reactions may cooccur with saline deposits and subsurface oceans.

  13. Microbial life at −13 °C in the brine of an ice-sealed Antarctic lake

    PubMed Central

    Murray, Alison E.; Kenig, Fabien; Fritsen, Christian H.; McKay, Christopher P.; Cawley, Kaelin M.; Edwards, Ross; Kuhn, Emanuele; McKnight, Diane M.; Ostrom, Nathaniel E.; Peng, Vivian; Ponce, Adrian; Priscu, John C.; Samarkin, Vladimir; Townsend, Ashley T.; Wagh, Protima; Young, Seth A.; Yung, Pung To; Doran, Peter T.

    2012-01-01

    The permanent ice cover of Lake Vida (Antarctica) encapsulates an extreme cryogenic brine ecosystem (−13 °C; salinity, 200). This aphotic ecosystem is anoxic and consists of a slightly acidic (pH 6.2) sodium chloride-dominated brine. Expeditions in 2005 and 2010 were conducted to investigate the biogeochemistry of Lake Vida’s brine system. A phylogenetically diverse and metabolically active Bacteria dominated microbial assemblage was observed in the brine. These bacteria live under very high levels of reduced metals, ammonia, molecular hydrogen (H2), and dissolved organic carbon, as well as high concentrations of oxidized species of nitrogen (i.e., supersaturated nitrous oxide and ∼1 mmol⋅L−1 nitrate) and sulfur (as sulfate). The existence of this system, with active biota, and a suite of reduced as well as oxidized compounds, is unusual given the millennial scale of its isolation from external sources of energy. The geochemistry of the brine suggests that abiotic brine-rock reactions may occur in this system and that the rich sources of dissolved electron acceptors prevent sulfate reduction and methanogenesis from being energetically favorable. The discovery of this ecosystem and the in situ biotic and abiotic processes occurring at low temperature provides a tractable system to study habitability of isolated terrestrial cryoenvironments (e.g., permafrost cryopegs and subglacial ecosystems), and is a potential analog for habitats on other icy worlds where water-rock reactions may cooccur with saline deposits and subsurface oceans. PMID:23185006

  14. Microbial life at -13 °C in the brine of an ice-sealed Antarctic lake.

    PubMed

    Murray, Alison E; Kenig, Fabien; Fritsen, Christian H; McKay, Christopher P; Cawley, Kaelin M; Edwards, Ross; Kuhn, Emanuele; McKnight, Diane M; Ostrom, Nathaniel E; Peng, Vivian; Ponce, Adrian; Priscu, John C; Samarkin, Vladimir; Townsend, Ashley T; Wagh, Protima; Young, Seth A; Yung, Pung To; Doran, Peter T

    2012-12-11

    The permanent ice cover of Lake Vida (Antarctica) encapsulates an extreme cryogenic brine ecosystem (-13 °C; salinity, 200). This aphotic ecosystem is anoxic and consists of a slightly acidic (pH 6.2) sodium chloride-dominated brine. Expeditions in 2005 and 2010 were conducted to investigate the biogeochemistry of Lake Vida's brine system. A phylogenetically diverse and metabolically active Bacteria dominated microbial assemblage was observed in the brine. These bacteria live under very high levels of reduced metals, ammonia, molecular hydrogen (H(2)), and dissolved organic carbon, as well as high concentrations of oxidized species of nitrogen (i.e., supersaturated nitrous oxide and ∼1 mmol⋅L(-1) nitrate) and sulfur (as sulfate). The existence of this system, with active biota, and a suite of reduced as well as oxidized compounds, is unusual given the millennial scale of its isolation from external sources of energy. The geochemistry of the brine suggests that abiotic brine-rock reactions may occur in this system and that the rich sources of dissolved electron acceptors prevent sulfate reduction and methanogenesis from being energetically favorable. The discovery of this ecosystem and the in situ biotic and abiotic processes occurring at low temperature provides a tractable system to study habitability of isolated terrestrial cryoenvironments (e.g., permafrost cryopegs and subglacial ecosystems), and is a potential analog for habitats on other icy worlds where water-rock reactions may cooccur with saline deposits and subsurface oceans. PMID:23185006

  15. High temperature two component explosive

    DOEpatents

    Mars, James E.; Poole, Donald R.; Schmidt, Eckart W.; Wang, Charles

    1981-01-01

    A two component, high temperature, thermally stable explosive composition comprises a liquid or low melting oxidizer and a liquid or low melting organic fuel. The oxidizer and fuel in admixture are incapable of substantial spontaneous exothermic reaction at temperatures on the order of 475.degree. K. At temperatures on the order of 475.degree. K., the oxidizer and fuel in admixture have an activation energy of at least about 40 kcal/mol. As a result of the high activation energy, the preferred explosive compositions are nondetonable as solids at ambient temperature, and become detonable only when heated beyond the melting point. Preferable oxidizers are selected from alkali or alkaline earth metal nitrates, nitrites, perchlorates, and/or mixtures thereof. Preferred fuels are organic compounds having polar hydrophilic groups. The most preferred fuels are guanidinium nitrate, acetamide and mixtures of the two. Most preferred oxidizers are eutectic mixtures of lithium nitrate, potassium nitrate and sodium nitrate, of sodium nitrite, sodium nitrate and potassium nitrate, and of potassium nitrate, calcium nitrate and sodium nitrate.

  16. High temperature structural sandwich panels

    NASA Astrophysics Data System (ADS)

    Papakonstantinou, Christos G.

    High strength composites are being used for making lightweight structural panels that are being employed in aerospace, naval and automotive structures. Recently, there is renewed interest in use of these panels. The major problem of most commercial available sandwich panels is the fire resistance. A recently developed inorganic matrix is investigated for use in cases where fire and high temperature resistance are necessary. The focus of this dissertation is the development of a fireproof composite structural system. Sandwich panels made with polysialate matrices have an excellent potential for use in applications where exposure to high temperatures or fire is a concern. Commercial available sandwich panels will soften and lose nearly all of their compressive strength temperatures lower than 400°C. This dissertation consists of the state of the art, the experimental investigation and the analytical modeling. The state of the art covers the performance of existing high temperature composites, sandwich panels and reinforced concrete beams strengthened with Fiber Reinforced Polymers (FRP). The experimental part consists of four major components: (i) Development of a fireproof syntactic foam with maximum specific strength, (ii) Development of a lightweight syntactic foam based on polystyrene spheres, (iii) Development of the composite system for the skins. The variables are the skin thickness, modulus of elasticity of skin and high temperature resistance, and (iv) Experimental evaluation of the flexural behavior of sandwich panels. Analytical modeling consists of a model for the flexural behavior of lightweight sandwich panels, and a model for deflection calculations of reinforced concrete beams strengthened with FRP subjected to fatigue loading. The experimental and analytical results show that sandwich panels made with polysialate matrices and ceramic spheres do not lose their load bearing capability during severe fire exposure, where temperatures reach several

  17. Silica separation from reinjection brines at Monte Amiata geothermal plants, Italy

    SciTech Connect

    Vitolo, S.; Cialdella, M.L. . Dipartimento di Ingegneria Chimica)

    1994-06-01

    A process for the separation of silica from geothermal reinjection brines is reported, in which the phases of coagulation, sedimentation and filtration of silica are involved. The effectiveness of lime and calcium chloride as coagulating agents has been investigated and the separating operations have been set out. Attention has been focused on Monte Amiata reinjection geothermal brines, whose scaling effect causes serious problems in the operation and maintenance of reinjection facilities. The study has been conducted using different amounts of added coagulants and at different temperatures, to determine optimal operating conditions. Though calcium chloride was revealed to be effective as a coagulant of the polymeric silica fraction, lime has also proved capable of removing monomeric dissolved silica at high dosages. Investigation on the behavior of coagulated brine has revealed the feasibility of separating the coagulated silica by sedimentation and filtration.

  18. Motor for High Temperature Applications

    NASA Technical Reports Server (NTRS)

    Roopnarine (Inventor)

    2013-01-01

    A high temperature motor has a stator with poles formed by wire windings, and a rotor with magnetic poles on a rotor shaft positioned coaxially within the stator. The stator and rotor are built up from stacks of magnetic-alloy laminations. The stator windings are made of high temperature magnet wire insulated with a vitreous enamel film, and the wire windings are bonded together with ceramic binder. A thin-walled cylinder is positioned coaxially between the rotor and the stator to prevent debris from the stator windings from reaching the rotor. The stator windings are wound on wire spools made of ceramic, thereby avoiding need for mica insulation and epoxy/adhesive. The stator and rotor are encased in a stator housing with rear and front end caps, and rear and front bearings for the rotor shaft are mounted on external sides of the end caps to keep debris from the motor migrating into the bearings' races.

  19. High Temperature Heat Exchanger Project

    SciTech Connect

    Anthony E. Hechanova, Ph.D.

    2008-09-30

    The UNLV Research Foundation assembled a research consortium for high temperature heat exchanger design and materials compatibility and performance comprised of university and private industry partners under the auspices of the US DOE-NE Nuclear Hydrogen Initiative in October 2003. The objectives of the consortium were to conduct investigations of candidate materials for high temperature heat exchanger componets in hydrogen production processes and design and perform prototypical testing of heat exchangers. The initial research of the consortium focused on the intermediate heat exchanger (located between the nuclear reactor and hydrogen production plan) and the components for the hydrogen iodine decomposition process and sulfuric acid decomposition process. These heat exchanger components were deemed the most challenging from a materials performance and compatibility perspective

  20. High pressure and high temperature apparatus

    DOEpatents

    Voronov, Oleg A.

    2005-09-13

    A design for high pressure/high temperature apparatus and reaction cell to achieve .about.30 GPa pressure in .about.1 cm volume and .about.100 GPa pressure in .about.1 mm volumes and 20-5000.degree. C. temperatures in a static regime. The device includes profiled anvils (28) action on a reaction cell (14, 16) containing the material (26) to be processed. The reaction cell includes a heater (18) surrounded by insulating layers and screens. Surrounding the anvils are cylindrical inserts and supporting rings (30-48) whose hardness increases towards the reaction cell. These volumes may be increased considerably if applications require it, making use of presses that have larger loading force capability, larger frames and using larger anvils.

  1. High temperature solar thermal receiver

    NASA Technical Reports Server (NTRS)

    1979-01-01

    A design concept for a high temperature solar thermal receiver to operate at 3 atmospheres pressure and 2500 F outlet was developed. The performance and complexity of windowed matrix, tube-header, and extended surface receivers were evaluated. The windowed matrix receiver proved to offer substantial cost and performance benefits. An efficient and cost effective hardware design was evaluated for a receiver which can be readily interfaced to fuel and chemical processes or to heat engines for power generation.

  2. HIGH TEMPERATURE MICROSCOPE AND FURNACE

    DOEpatents

    Olson, D.M.

    1961-01-31

    A high-temperature microscope is offered. It has a reflecting optic situated above a molten specimen in a furnace and reflecting the image of the same downward through an inert optic member in the floor of the furnace, a plurality of spaced reflecting plane mirrors defining a reflecting path around the furnace, a standard microscope supported in the path of and forming the end terminus of the light path.

  3. High temperature turbine engine structure

    DOEpatents

    Carruthers, William D.; Boyd, Gary L.

    1993-01-01

    A high temperature ceramic/metallic turbine engine includes a metallic housing which journals a rotor member of the turbine engine. A ceramic disk-like shroud portion of the engine is supported on the metallic housing portion and maintains a close running clearance with the rotor member. A ceramic spacer assembly maintains the close running clearance of the shroud portion and rotor member despite differential thermal movements between the shroud portion and metallic housing portion.

  4. High temperature turbine engine structure

    DOEpatents

    Carruthers, William D.; Boyd, Gary L.

    1994-01-01

    A high temperature ceramic/metallic turbine engine includes a metallic housing which journals a rotor member of the turbine engine. A ceramic disk-like shroud portion of the engine is supported on the metallic housing portion and maintains a close running clearance with the rotor member. A ceramic spacer assembly maintains the close running clearance of the shroud portion and rotor member despite differential thermal movements between the shroud portion and metallic housing portion.

  5. High temperature turbine engine structure

    DOEpatents

    Carruthers, William D.; Boyd, Gary L.

    1992-01-01

    A high temperature ceramic/metallic turbine engine includes a metallic housing which journals a rotor member of the turbine engine. A ceramic disk-like shroud portion of the engine is supported on the metallic housing portion and maintains a close running clearance with the rotor member. A ceramic spacer assembly maintains the close running clearance of the shroud portion and rotor member despite differential thermal movements between the shroud portion and metallic housing portion.

  6. High-temperature geothermal cableheads

    SciTech Connect

    Coquat, J.A.; Eifert, R.W.

    1981-11-01

    Two high-temperature, corrosion-resistant logging cableheads which use metal seals and a stable fluid to achieve proper electrical terminations and cable-sonde interfacings are described. A tensile bar provides a calibrated yield point, and a cone assembly anchors the cable armor to the head. Electrical problems of the sort generally ascribable to the cable-sonde interface were absent during demonstration hostile-environment loggings in which these cableheads were used.

  7. High temperature catalytic membrane reactors

    SciTech Connect

    Not Available

    1990-03-01

    Current state-of-the-art inorganic oxide membranes offer the potential of being modified to yield catalytic properties. The resulting modules may be configured to simultaneously induce catalytic reactions with product concentration and separation in a single processing step. Processes utilizing such catalytically active membrane reactors have the potential for dramatically increasing yield reactions which are currently limited by either thermodynamic equilibria, product inhibition, or kinetic selectivity. Examples of commercial interest include hydrogenation, dehydrogenation, partial and selective oxidation, hydrations, hydrocarbon cracking, olefin metathesis, hydroformylation, and olefin polymerization. A large portion of the most significant reactions fall into the category of high temperature, gas phase chemical and petrochemical processes. Microporous oxide membranes are well suited for these applications. A program is proposed to investigate selected model reactions of commercial interest (i.e. dehydrogenation of ethylbenzene to styrene and dehydrogenation of butane to butadiene) using a high temperature catalytic membrane reactor. Membranes will be developed, reaction dynamics characterized, and production processes developed, culminating in laboratory-scale demonstration of technical and economic feasibility. As a result, the anticipated increased yield per reactor pass economic incentives are envisioned. First, a large decrease in the temperature required to obtain high yield should be possible because of the reduced driving force requirement. Significantly higher conversion per pass implies a reduced recycle ratio, as well as reduced reactor size. Both factors result in reduced capital costs, as well as savings in cost of reactants and energy.

  8. Effects of brine concentration on lipid oxidation and fatty acids profile of hot smoked tuna ( Thunnus albacares ) stored at refrigerated temperature.

    PubMed

    Guizani, Nejib; Rahman, Mohammad Shafiur; Al-Ruzeiqi, Mohamed Hamad; Al-Sabahi, Jamal Nasser; Sureshchandran, Sithara

    2014-03-01

    This work evaluated the lipid oxidation and the changes in fatty acids in hot-smoked tuna (Thunnus albacares) as a function of brine concentration. Fresh, commercially harvested tuna fish samples were purchased from a local supermarket. The fish were first immersed for 30 min in a brine solution at 5, 10, or 15% sodium chloride concentration and were then smoked at 50 °C for 3 h followed by 1 h at 60 °C and 3 h at 105 °C. The fish were then dried for 17 h, cooled and stored at 4 °C. Oxidative rancidity was measured by the peroxide value (PV), and thiobarbituric acid number (TBA) and fatty acids profile by GC-MS. Oxidative rancidity increased with storage time. The PV and TBARS values were more pronounced for samples immersed in 10% brine solution during the first 27 days of storage, whereas the lowest increase was observed for samples treated with 15% salt. Fatty acid concentration exhibited changes after smoking, and this was varied with salt concentration. The palmitic acid and stearic acid, the two main saturated fatty acids in tuna, increased after smoking at all brine concentration, whereas the contents of oleic acid, eicosapentaenoic acid and docosahexaenoic acid decreased. In conclusion, 15% NaCl-treated tuna gave smoked product with less lipid oxidation and a fatty acid profile comparable to that for 5 and 10% NaCl-treated samples. PMID:24587535

  9. High temperature polymer matrix composites

    NASA Technical Reports Server (NTRS)

    Meador, Michael A.

    1987-01-01

    With the increased emphasis on high performance aircraft the need for lightweight, thermal/oxidatively stable materials is growing. Because of their ease of fabrication, high specific strength, and ability to be tailored chemically to produce a variety of mechanical and physical properties, polymers and polymer matrix composites present themselves as attractive materials for a number of aeropropulsion applications. In the early 1970s researchers at the NASA Lewis Research Center developed a highly processable, thermally stable (600 F) polyimide, PMR-15. Since that time, PMR-15 has become commercially available and has found use in military aircraft, in particular, the F-404 engine for the Navy's F/A-18 strike fighter. The NASA Lewis'contributions to high temperature polymer matrix composite research will be discussed as well as current and future directions.

  10. High temperature jet fuel stabilizers

    SciTech Connect

    Yoon, E.M.; Selvaraj, L.; Stallman, J.B.

    1996-10-01

    We have previously discussed the rationale for development of jet fuels with enhanced thermal stability at temperatures above 400{degrees}C. At these temperatures we are encroaching into the so-called pyrolysis regime, where the cleavage of carbon-carbon bonds into free radicals is facile and leads to the rapid degradation of aliphatic hydrocarbons. Notwithstanding, we established that the formation of carbonaceous materials is significantly retarded in hydrocarbon mixtures containing molecules such as benzyl alcohol (BzOH). It was ascertained that BzOH acts as a hydrogen donor capping aliphatic radicals formed at temperatures > 400{degrees}C while transforming into relatively stable products. These results suggested is superior high temperature thermal stabilizers might be found among the more conventional hydrogen donors that find application in coal liquefaction and similar hydrogenation processes. Here we present the results of {open_quotes}screening{close_quotes} and kinetic studies of traditional hydrogen donors, such as tetralin, tetrahydroquinoline and the like, together with simple derivatives designed to test the importance of specific factors in the thermal stabilization of jet fuels.

  11. Rheological Properties of Silica Nanoparticles in Brine and Brine-Surfactant Systems

    NASA Astrophysics Data System (ADS)

    Pales, Ashley; Kinsey, Erin; Li, Chunyan; Mu, Linlin; Bai, Lingyun; Clifford, Heather; Darnault, Christophe

    2016-04-01

    Rheological Properties of Silica Nanoparticles in Brine and Brine-Surfactant Systems Ashley R. Pales, Erin Kinsey, Chunyan Li, Linlin Mu, Lingyun Bai, Heather Clifford, and Christophe J. G. Darnault Department of Environmental Engineering and Earth Sciences, Laboratory of Hydrogeoscience and Biological Engineering, L.G. Rich Environmental Laboratory, Clemson University, Clemson, SC, USA Nanofluids are suspensions of nanometer sized particles in any fluid base, where the nanoparticles effect the properties of the fluid base. Commonly, nanofluids are water based, however, other bases such as ethylene-glycol, glycerol, and propylene-glycol, have been researched to understand the rheological properties of the nanofluids. This work aims to understand the fundamental rheological properties of silica nanoparticles in brine based and brine-surfactant based nanofluids with temperature variations. This was done by using variable weight percent of silica nanoparticles from 0.001% to 0.1%. Five percent brine was used to create the brine based nanofluids; and 5% brine with 2CMC of Tween 20 nonionic surfactant (Sigma-Aldrich) was used to create the brine-surfactant nanofluid. Rheological behaviors, such as shear rate, shear stress, and viscosity, were compared between these nanofluids at 20C and at 60C across the varied nanoparticle wt%. The goal of this work is to provide a fundamental basis for future applied testing for enhanced oil recovery. It is hypothesized that the addition of surfactant will have a positive impact on nanofluid properties that will be useful for enhance oil recovery. Differences have been observed in preliminary data analysis of the rheological properties between these two nanofluids indicating that the surfactant is having the hypothesized effect.

  12. Investigating Brine Shrimp.

    ERIC Educational Resources Information Center

    Duran, Lena Ballone

    2003-01-01

    Presents a brine shrimp activity designed for students in grades 5-12 to foster authentic scientific inquiry in addition to providing an engaging and exciting avenue for student exploration. Emphasizes that inquiry should be a critical component in the science classroom. (KHR)

  13. Brine stability study

    DOE Data Explorer

    Gary Garland

    2015-04-15

    This is a study of the brine formulations that we were using in our testing were stable over time. The data includes charts, as well as, all of the original data from the ICP-MS runs to complete this study.

  14. High temperature PEM fuel cells

    NASA Astrophysics Data System (ADS)

    Zhang, Jianlu; Xie, Zhong; Zhang, Jiujun; Tang, Yanghua; Song, Chaojie; Navessin, Titichai; Shi, Zhiqing; Song, Datong; Wang, Haijiang; Wilkinson, David P.; Liu, Zhong-Sheng; Holdcroft, Steven

    There are several compelling technological and commercial reasons for operating H 2/air PEM fuel cells at temperatures above 100 °C. Rates of electrochemical kinetics are enhanced, water management and cooling is simplified, useful waste heat can be recovered, and lower quality reformed hydrogen may be used as the fuel. This review paper provides a concise review of high temperature PEM fuel cells (HT-PEMFCs) from the perspective of HT-specific materials, designs, and testing/diagnostics. The review describes the motivation for HT-PEMFC development, the technology gaps, and recent advances. HT-membrane development accounts for ∼90% of the published research in the field of HT-PEMFCs. Despite this, the status of membrane development for high temperature/low humidity operation is less than satisfactory. A weakness in the development of HT-PEMFC technology is the deficiency in HT-specific fuel cell architectures, test station designs, and testing protocols, and an understanding of the underlying fundamental principles behind these areas. The development of HT-specific PEMFC designs is of key importance that may help mitigate issues of membrane dehydration and MEA degradation.

  15. CO2-Brine Rheology Could Suppress Leakage From Geologic Carbon Sequestration Sites

    NASA Astrophysics Data System (ADS)

    Wang, S.; Clarens, A. F.

    2011-12-01

    Geologic carbon sequestration (GCS) in the deep subsurface is an attractive means for storing large volumes of CO2 over the long term. GCS is predicated on there being minimal leakage of CO2 to the surface since this would negate the climate change benefits and could also create a human health risk. Despite the importance of understanding leakage processes to GCS deployment, the phenomena remain especially difficult to characterize because CO2, driven by buoyant forces out of host formations, must travel over long length scales, encountering varied geologic formations and endogenous brines, and experiencing a wide range of shear, temperature and pressure conditions that result in complex phase behavior. This study explores the rheology of CO2-brine mixtures in an effort to better characterize the geophysics of a rising parcel of CO2 in the subsurface. Experimental work in this area to date has assumed that CO2-brine mixtures will exhibit simple Newtonian behavior. The hypothesis of this work is that CO2-brine mixtures will move through porous media generating high shear rates, caused by the small pore sizes, that could result in more complex flow phenomena. The rheological properties of single and multiphase CO2-brine mixtures were measured over a range of GCS-relevant temperature, pressure, ionic strength, and shear conditions using a rotational rheometer fitted with a high-pressure vessel and a low viscosity measurement unit. Under liquid-liquid equilibrium (LLE) conditions CO2-brine mixtures were found to exhibit consistently Newtonian behavior with the effective viscosity generally increasing with respect to CO2(aq) concentration. A small dip in viscosity occurs at the pressure corresponding to the transition of CO2 from liquid to gas but this minor effect is not likely to have an appreciable impact on leakage rates. More significantly, under vapor-liquid equilibrium (VLE) conditions, CO2-brine suspensions exhibit complex viscoelastic behavior that could

  16. Compensated High Temperature Strain Gage

    NASA Technical Reports Server (NTRS)

    1994-01-01

    A device for measuring strain in substrates at high temperatures in which the thermally induced apparent strain is nulled is described. Two gages are used, one active gage and one compensating gage. Both gages are placed on the substrate to be gaged; the active gage is attached such that it responds to mechanical and thermally induced apparent strain while the compensating gage is attached such that it does not respond to mechanical strain and and measures only thermally induced apparent strain. A thermal blanket is placed over the two gages to maintain the gages at the same temperature. The two gages are wired as adjacent arms of a wheatstone bridge which nulls the thermally induced apparent strain giving a true reading of the mechanical strain in the substrate.

  17. Ultra-High Temperature Ceramics

    NASA Technical Reports Server (NTRS)

    Rasky, Dan; Bull, Jeff

    1994-01-01

    Recent developments in ultra-high temperature ceramic composites, and their application to advanced vehicle thermal protection systems will be discussed. Research and testing of refractory ceramics has resulted in the identification of a new family of ceramic composites that promise temperature performance to 4000 F+, significantly beyond the current state-of-the-art of reusable systems which are limited to approximately 300 F. This new family of materials includes zirconium and hafnium diboride composites with various reinforcements, such as fibers and particulates. Preliminary material characterization and testing results, including plasma arc-jet testing of prototype vehicle components, will be described. Future directions for the research and material development activities will also be discussed.

  18. Evaluation of Brine Processing Technologies for Spacecraft Wastewater

    NASA Technical Reports Server (NTRS)

    Shaw, Hali L.; Flynn, Michael; Wisniewski, Richard; Lee, Jeffery; Jones, Harry; Delzeit, Lance; Shull, Sarah; Sargusingh, Miriam; Beeler, David; Howard, Jeanie; Howard, Kevin; Harris, Linden; Parodi, Jurek; Kawashima, Brian

    2015-01-01

    Brine drying systems may be used in spaceflight. There are several advantages to using brine processing technologies for long-duration human missions including a reduction in resupply requirements and achieving high water recovery ratios. The objective of this project was to evaluate four technologies for the drying of spacecraft water recycling system brine byproducts. The technologies tested were NASA's Forward Osmosis Brine Drying (FOBD), Paragon's Ionomer Water Processor (IWP), NASA's Brine Evaporation Bag (BEB) System, and UMPQUA's Ultrasonic Brine Dewatering System (UBDS). The purpose of this work was to evaluate the hardware using feed streams composed of brines similar to those generated on board the International Space Station (ISS) and future exploration missions. The brine formulations used for testing were the ISS Alternate Pretreatment and Solution 2 (Alt Pretreat). The brines were generated using the Wiped-film Rotating-disk (WFRD) evaporator, which is a vapor compression distillation system that is used to simulate the function of the ISS Urine Processor Assembly (UPA). Each system was evaluated based on the results from testing and Equivalent System Mass (ESM) calculations. A Quality Function Deployment (QFD) matrix was also developed as a method to compare the different technologies based on customer and engineering requirements.

  19. Preliminary Feasibility Testing of the BRIC Brine Water Recovery Concept

    NASA Technical Reports Server (NTRS)

    Callahan, Michael R.; Pensinger, Stuart; Pickering, Karen D.

    2011-01-01

    The Brine Residual In-Containment (BRIC) concept was developed as a new technology to recover water from spacecraft wastewater brines. Such capability is considered critical to closing the water loop and achieving a sustained human presence in space. The intention of the BRIC concept is to increase the robustness and efficiency of the dewatering process by performing drying inside the container used for the final disposal of the residual brine solid. Recent efforts in the development of BRIC have focused on preliminary feasibility testing using a laboratory- assembled pre-prototype unit. Observations of the drying behavior of actual brine solutions processed under BRIC-like conditions has been of particular interest. To date, experiments conducted with three types of analogue spacecraft wastewater brines have confirmed the basic premise behind the proposed application of in-place drying for these solutions. Specifically, the dried residual mass from these solutions have tended to exhibit characteristics of adhesion and flow that are expected to continue to challenge process stream management in spacecraft brine dewatering system designs. Yet, these same characteristics may favor the development of capillary- and surface-tension-based approaches envisioned as part of an ultimate microgravity-compatible BRIC design. In addition, preliminary feasibility testing of the BRIC pre-prototype confirmed that high rates of water recovery, up to 98% of the available brine water, may be possible while still removing the majority of the brine contaminants from the influent brine stream. These and other observations from testing are reported.

  20. Geothermal fracture stimulation technology. Volume II. High-temperature proppant testing

    SciTech Connect

    Not Available

    1980-07-01

    Data were obtained from a newly built proppant tester, operated at actual geothermal temperatures. The short term test results show that most proppants are temperature sensitive, particularly at the higher closure stresses. Many materials have been tested using a standard short-term test, i.e., fracture-free sand, bauxite, and a resin-coated sand retained good permeability at the high fluid temperatures in brine over a range of closure stresses. The tests were designed to simulate normal closure stress ranges for geothermal wells which are estimated to be from 2000 to 6000 psi. Although the ultra high closure stresses in oil and gas wells need not be considered with present geothermal resources, there is a definite need for chemically inert proppants that will retain high permeability for long time periods in the high temperature formations.

  1. High temperature sealed electrochemical cell

    SciTech Connect

    Valentin Chung, Brice Hoani; Burke, Paul J.; Sadoway, Donald R.

    2015-10-06

    A cell for high temperature electrochemical reactions is provided. The cell includes a container, at least a portion of the container acting as a first electrode. An extension tube has a first end and a second end, the extension tube coupled to the container at the second end forming a conduit from the container to said first end. A second electrode is positioned in the container and extends out of the container via the conduit. A seal is positioned proximate the first end of the extension tube, for sealing the cell.

  2. Passivation of high temperature superconductors

    NASA Technical Reports Server (NTRS)

    Vasquez, Richard P. (Inventor)

    1991-01-01

    The surface of high temperature superconductors such as YBa2Cu3O(7-x) are passivated by reacting the native Y, Ba and Cu metal ions with an anion such as sulfate or oxalate to form a surface film that is impervious to water and has a solubility in water of no more than 10(exp -3) M. The passivating treatment is preferably conducted by immersing the surface in dilute aqueous acid solution since more soluble species dissolve into the solution. The treatment does not degrade the superconducting properties of the bulk material.

  3. High temperature insulation barrier composite

    NASA Technical Reports Server (NTRS)

    Onstott, Joseph W. (Inventor)

    1989-01-01

    A composite material suitable for providing insulation for the nozzle structure of the Space Shuttle and other similar surfaces is disclosed. The composite layer is comprised of an outer skin layer of nickel chromium and an interleaved inner region comprising a top layer of nickel chromium foil which acts as a primary convective shield. There are at least two layers of alumina batting adjacent to the layers of silicon carbide fabric. An additional layer of nickel chromium foil is used as a secondary convective shield. The composite is particularly advantageous for use as nozzle insulation because of its ability to withstand high reentry temperatures, its flexibility, oxidation resistance, low conductivity, and light weight.

  4. Advanced high-temperature batteries

    NASA Technical Reports Server (NTRS)

    Nelson, Paul A.

    1989-01-01

    The promise of very high specific energy and power was not yet achieved for practical battery systems. Some recent approaches are discussed for new approaches to achieving high performance for lithium/DeS2 cells and sodium/metal chloride cells. The main problems for the development of successful LiAl/FeS2 cells were the instability of the FeS2 electrode, which has resulted in rapidly declining capacity, the lack of an internal mechanism for accommodating overcharge of a cell, thus requiring the use of external charge control on each individual cell, and the lack of a suitable current collector for the positive electrode other than expensive molybdenum sheet material. Much progress was made in solving the first two problems. Reduction of the operating temperatures to 400 C by a change in electrolyte composition has increased the expected life to 1000 cycles. Also, a lithium shuttle mechanism was demonstrated for selected electrode compositions that permits sufficient overcharge tolerance to adjust for the normally expected cell-to-cell deviation in coulombic efficiency. Sodium/sulfur batteries and sodium/metal chloride batteries have demonstrated good reliability and long cycle life. For applications where very high power is desired, new electrolyte coinfigurations would be required. Design work was carried out for the sodium/metal chloride battery that demonstrates the feasibility of achieving high specific energy and high power for large battery cells having thin-walled high-surface area electrolytes.

  5. Mirabilite solubility in equilibrium sea ice brines

    NASA Astrophysics Data System (ADS)

    Butler, Benjamin Miles; Papadimitriou, Stathys; Santoro, Anna; Kennedy, Hilary

    2016-06-01

    The sea ice microstructure is permeated by brine channels and pockets that contain concentrated seawater-derived brine. Cooling the sea ice results in further formation of pure ice within these pockets as thermal equilibrium is attained, resulting in a smaller volume of increasingly concentrated residual brine. The coupled changes in temperature and ionic composition result in supersaturation of the brine with respect to mirabilite (Na2SO4·10H2O) at temperatures below -6.38 °C, which consequently precipitates within the sea ice microstructure. Here, mirabilite solubility in natural and synthetic seawater derived brines, representative of sea ice at thermal equilibrium, has been measured in laboratory experiments between 0.2 and -20.6 °C, and hence we present a detailed examination of mirabilite dynamics within the sea ice system. Below -6.38 °C mirabilite displays particularly large changes in solubility as the temperature decreases, and by -20.6 °C its precipitation results in 12.90% and 91.97% reductions in the total dissolved Na+ and SO42- concentrations respectively, compared to that of conservative seawater concentration. Such large non-conservative changes in brine composition could potentially impact upon the measurement of sea ice brine salinity and pH, whilst the altered osmotic conditions may create additional challenges for the sympagic organisms that inhabit the sea ice system. At temperatures above -6.38 °C, mirabilite again displays large changes in solubility that likely aid in impeding its identification in field samples of sea ice. Our solubility measurements display excellent agreement with that of the FREZCHEM model, which was therefore used to supplement our measurements to colder temperatures. Measured and modelled solubility data were incorporated into a 1D model for the growth of first-year Arctic sea ice. Model results ultimately suggest that mirabilite has a near ubiquitous presence in much of the sea ice on Earth, and illustrate the

  6. Hydrothermal fluid migration and brine pool formation in the Red Sea: the Atlantis II Deep

    NASA Astrophysics Data System (ADS)

    Schardt, Christian

    2016-01-01

    Numerical heat and fluid flow simulations of the Atlantis II Deep in the Red Sea were conducted to investigate the development, migration, and discharge of hydrothermal fluids into a submarine depression and determine the conditions necessary to form a brine pool. High-salinity fluids are predicted to form by leaching Miocene evaporates, migrate and convect within young oceanic crust, and discharge onto the seafloor. Predicted fluid discharge temperatures ( T max, 301 °C), discharge fluid velocities ( V max, 0.09 m/s), and salinities ( S max, 21 wt%) increase over time and reach values comparable to modern seafloor observations. Established convection patterns and discharge behavior are robust and are not greatly affected by geometry of rock property changes. Modeling results were used to calculate the minimum conditions for hydrothermal fluids from a developing hydrothermal system to mix with seawater, reverse buoyancy, and begin to form a brine pool in a submarine depression. Under conditions encountered on the seafloor ( T, 25-300 °C; S, 5-25 wt%), fluid mixtures predicted to pond on the seafloor range from late in the mixing process (99 %) at low temperatures ( T, 26 °C) to much earlier (36 % mixing) at higher temperatures ( T, 94 °C). A model of brine pool evolution is proposed that describes the processes and conditions necessary to initiate brine pool formation and compares formation conditions with accumulated ore material in the Atlantis II Deep and other locations.

  7. High modulus high temperature glass fibers

    NASA Technical Reports Server (NTRS)

    Bacon, J. F.

    1973-01-01

    The search for a new high-modulus, high-temperature glass fiber involved the preparation of 500 glass compositions lying in 12 glass fields. These systems consisted primarily of low atomic number oxides and rare-earth oxides. Direct optical measurements of the kinetics of crystallization of the cordierite-rare earth system, for example, showed that the addition of rare-earth oxides decreased the rate of formation of cordierite crystals. Glass samples prepared from these systems proved that the rare-earth oxides made large specific contributions to the Young's modulus of the glasses. The best glasses have moduli greater than 21 million psi, the best glass fibers have moduli greater than 18 million psi, and the best glass fiber-epoxy resin composites have tensile strengths of 298,000 psi, compressive strengths of at least 220,000 psi, flexural strengths of 290,000 psi, and short-beam shear strengths of almost 17,000 psi.

  8. Moisture variations in brine-salted pasta filata cheese.

    PubMed

    Kindstedt, P S

    2001-01-01

    A study was made of the moisture distribution in brine-salted pasta filata cheese. Brine-salted cheeses usually develop reasonably smooth and predictable gradients of decreasing moisture from center to surface, resulting from outward diffusion of moisture in response to inward diffusion of salt. However, patterns of moisture variation within brine-salted pasta filata cheeses, notably pizza cheese, are more variable and less predictable because of the peculiar conditions that occur when warm cheese is immersed in cold brine. In this study, cold brining resulted in less moisture loss from the cheese surface to the brine. Also it created substantial temperature gradients within the cheese, which persisted after brining and influenced the movement of moisture within the cheese independently of that caused by the inward diffusion of salt. Depending on brining conditions and age, pizza cheese may contain decreasing, increasing, or irregular gradients of moisture from center to surface, which may vary considerably at different locations within a single block. This complicates efforts to obtain representative samples for moisture and composition testing. Dicing the entire block into small (e.g., 1.5 cm) cubes and collecting a composite sample after thorough mixing may serve as a practical sampling approach for manufacturers and users of pizza cheese that have ready access to dicing equipment.

  9. Experimental study of the stability and activity of brines on the surface of Mars

    NASA Astrophysics Data System (ADS)

    Altheide, Travis S.

    This work contributes to the understanding of liquid water stability, with an emphasis on the role that dissolved solutes may have had on liquid water formation on Mars, past and present. In chapter 2, the stability of liquid water under martian conditions is explored through experiments on ferric sulfate brines. First, it is demonstrated that such brines can be formed starting from typical martian mineralogy. Ferric sulfates are quite soluble, up to 48 wt%, and can form solutions which remain liquid down to 205 +/-1 K at the eutectic. As a result of low water activities, these solutions exhibit evaporation rates 20 times lower than pure water. The combination of a low eutectic point and low evaporation rates allow subsurface liquids to be stable at high martian latitudes, where the majority of gullies and viscous flow features are located. Thus, the characteristics of ferric sulfate brines were further investigated in chapter 3, where the viscous properties of such solutions were measured, with respect to changing temperature and concentration. Using these results, the viscosity of these solutions on the formation of gullies was considered, where calculated fluid flow velocities were found to be in accordance with some estimates from image analyses of gully formations. In chapter 4, other Mars-relevant brines were studied and characterized under martian surface conditions. Magnesium and ferrous sulfate, and magnesium and ferric chloride brines were found to stabilize water, through lower evaporation rates and freezing point depression, much like the ferric sulfate brines. For these sulfate brines, it was found that the thermodynamic process of phase change, i.e. ice formation and/or salt crystallization, can affect the kinetic process of evaporation, through very low water activities in solution. Furthermore, in chapter 5 these studies were extended to recent results from the Phoenix mission, by examining the stability of perchlorate brines under conditions

  10. Studies of brine chemistry and scaling at the Salton Sea Geothermal field

    NASA Astrophysics Data System (ADS)

    Harrar, J. E.

    1981-01-01

    Features of studies related to brine chemistry and scaling are reported. The results of investigations of brine chemistry, the effects of brine acidification and organic additives on the rate of scale formation and scale composition, and the use of other additives for scale control are summarized. High salinity, high silica geothermal brines were studied and it was shown that the silica and sulfide scales formed from these brines could be eliminated by lowering the pH of brine. The following steps were completed: testing of technical chemical solutions to the scaling problem; finding low cost metallic materials that will resist the brine; proving a method for the treatment of spend brine for injection; perfection of chemical measurement techniques. Most environmental issues are addressed and first increments of electrical power are generated.

  11. Multifunctional, High-Temperature Nanocomposites

    NASA Technical Reports Server (NTRS)

    Connell, John W.; Smith, Joseph G.; Siochi, Emilie J.; Working, Dennis C.; Criss, Jim M.; Watson, Kent A.; Delozier, Donavon M.; Ghose, Sayata

    2007-01-01

    In experiments conducted as part of a continuing effort to incorporate multifunctionality into advanced composite materials, blends of multi-walled carbon nanotubes and a resin denoted gPETI-330 h (wherein gPETI h is an abbreviation for gphenylethynyl-terminated imide h) were prepared, characterized, and fabricated into moldings. PETI-330 was selected as the matrix resin in these experiments because of its low melt viscosity (<10 poise at a temperature of 280 C), excellent melt stability (lifetime >2 hours at 280 C), and high temperature performance (>1,000 hours at 288 C). The multi-walled carbon nanotubes (MWCNTs), obtained from the University of Kentucky, were selected because of their electrical and thermal conductivity and their small diameters. The purpose of these experiments was to determine the combination of thermal, electrical, and mechanical properties achievable while still maintaining melt processability. The PETI-330/MWCNT mixtures were prepared at concentrations ranging from 3 to 25 weight-percent of MWCNTs by dry mixing of the constituents in a ball mill using zirconia beads. The resulting powders were characterized for degree of mixing and thermal and rheological properties. The neat resin was found to have melt viscosity between 5 and 10 poise. At 280 C and a fixed strain rate, the viscosity was found to increase with time. At this temperature, the phenylethynyl groups do not readily react and so no significant curing of the resin occurred. For MWCNT-filled samples, melt viscosity was reasonably steady at 280 C and was greater in samples containing greater proportions of MWCNTs. The melt viscosity for 20 weightpercent of MWCNTs was found to be .28,000 poise, which is lower than the initial estimated allowable maximum value of 60,000 poise for injection molding. Hence, MWCNT loadings of as much as 20 percent were deemed to be suitable compositions for scale-up. High-resolution scanning electron microscopy (HRSEM) showed the MWCNTs to be well

  12. Sialons as high temperature insulators

    NASA Technical Reports Server (NTRS)

    Phillips, W. M.; Kuo, Y. S.

    1978-01-01

    Sialons were evaluated for application as high temperature electrical insulators in contact with molybdenum and tungsten components in hard vacuum applications. Both D.C. and variable frequency A.C. resistivity data indicate the sialons to have electrical resistivity similar to common oxide in the 1000 C or higher range. Metallographic evaluations indicate good bonding of the type 15R ALN polytype to molybdenum and tungsten. The beta prime or modified silicon nitride phase was unacceptable in terms of vacuum stability. Additives effect on electrical resistivity. Similar resistivity decreases were produced by additions of molybdenum or tungsten to form cermets. The use of hot pressing at 1800 C with ALN, Al2 O3 and Si3N4 starting powders produced a better product than did a combination of SiO2 and AIN staring powders. It was indicated that sialons will be suitable insulators in the 1600K range in contact with molybdenum or tungsten if they are produced as a pure ceramic and subsequently bonded to the metal components at temperatures in the 1600K range.

  13. Mars brine formation experiment

    NASA Technical Reports Server (NTRS)

    Moore, Jeffrey M.; Bullock, Mark A.; Stoker, Carol R.

    1993-01-01

    The presence of water-soluble cations and anions in the Martian regolith has been the subject of speculation for some time. Viking lander data provided evidence for salt-cemented crusts on the Martian surface. If the crusts observed at the two Viking landing sites are, in fact, cemented by salts, and these crusts are globally widespread, as IRTM-derived thermal inertia studies of the Martian surface seem to suggest, then evaporite deposits, probably at least in part derived from brines, are a major component of the Martian regolith. The composition of liquid brines in the subsurface, which not only may be major agents of physical weathering but may also presently constitute a major deep subsurface liquid reservoir, is currently unconstrained by experimental work. A knowledge of the chemical identity and rate of production of Martian brines is a critical first-order step toward understanding the nature of both these fluids and their precipitated evaporites. Laboratory experiments are being conducted to determine the identity and production rate of water-soluble ions that form in initially pure liquid water in contact with Mars-mixture gases and unaltered Mars-analog minerals.

  14. Faraday imaging at high temperatures

    DOEpatents

    Hackel, Lloyd A.; Reichert, Patrick

    1997-01-01

    A Faraday filter rejects background light from self-luminous thermal objects, but transmits laser light at the passband wavelength, thus providing an ultra-narrow optical bandpass filter. The filter preserves images so a camera looking through a Faraday filter at a hot target illuminated by a laser will not see the thermal radiation but will see the laser radiation. Faraday filters are useful for monitoring or inspecting the uranium separator chamber in an atomic vapor laser isotope separation process. Other uses include viewing welds, furnaces, plasma jets, combustion chambers, and other high temperature objects. These filters are can be produced at many discrete wavelengths. A Faraday filter consists of a pair of crossed polarizers on either side of a heated vapor cell mounted inside a solenoid.

  15. Faraday imaging at high temperatures

    DOEpatents

    Hackel, L.A.; Reichert, P.

    1997-03-18

    A Faraday filter rejects background light from self-luminous thermal objects, but transmits laser light at the passband wavelength, thus providing an ultra-narrow optical bandpass filter. The filter preserves images so a camera looking through a Faraday filter at a hot target illuminated by a laser will not see the thermal radiation but will see the laser radiation. Faraday filters are useful for monitoring or inspecting the uranium separator chamber in an atomic vapor laser isotope separation process. Other uses include viewing welds, furnaces, plasma jets, combustion chambers, and other high temperature objects. These filters are can be produced at many discrete wavelengths. A Faraday filter consists of a pair of crossed polarizers on either side of a heated vapor cell mounted inside a solenoid. 3 figs.

  16. High Temperature Particle Filtration Technology

    SciTech Connect

    Besmann, T.M.

    2001-11-13

    High temperature filtration can serve to improve the economic, environmental, and energy performance of chemical processes. This project was designed to evaluate the stability of filtration materials in the environments of the production of dimethyldichlorosilane (DDS). In cooperation with Dow Corning, chemical environments for the fluidized bed reactor where silicon is converted to DDS and the incinerator where vents are cornbusted were characterized. At Oak Ridge National Laboratory (ORNL) an exposure system was developed that could simulate these two environments. Filter samples obtained from third parties were exposed to the environments for periods up to 1000 hours. Mechanical properties before and after exposure were determined by burst-testing rings of filter material. The results indicated that several types of filter materials would likely perform well in the fluid bed environment, and two materials would be good candidates for the incinerator environment.

  17. High Temperature Capacitive Strain Gage

    NASA Technical Reports Server (NTRS)

    Wnuk, Stephen P., Jr.; Wnuk, Stephen P., III; Wnuk, V. P.

    1990-01-01

    Capacitive strain gages designed for measurements in wind tunnels to 2000 F were built and evaluated. Two design approaches were followed. One approach was based on fixed capacitor plates with a movable ground plane inserted between the plates to effect differential capacitive output with strain. The second approach was based on movable capacitor plates suspended between sapphire bearings, housed in a rugged body, and arranged to operate as a differential capacitor. A sapphire bearing gage (1/4 in. diameter x 1 in. in size) was built with a range of 50,000 and a resolution of 200 microstrain. Apparent strain on Rene' 41 was less than + or - 1000 microstrain from room temperature to 2000 F. Three gage models were built from the Ground Plane Differential concept. The first was 1/4 in. square by 1/32 in. high and useable to 700 F. The second was 1/2 in. square by 1/16 in. high and useable to 1440 F. The third, also 1/2 in. square by 1/16 in. high was expected to operate in the 1600 to 2000 F range, but was not tested because time and funding ended.

  18. High temperature control rod assembly

    DOEpatents

    Vollman, Russell E.

    1991-01-01

    A high temperature nuclear control rod assembly comprises a plurality of substantially cylindrical segments flexibly joined together in succession by ball joints. The segments are made of a high temperature graphite or carbon-carbon composite. The segment includes a hollow cylindrical sleeve which has an opening for receiving neutron-absorbing material in the form of pellets or compacted rings. The sleeve has a threaded sleeve bore and outer threaded surface. A cylindrical support post has a threaded shaft at one end which is threadably engaged with the sleeve bore to rigidly couple the support post to the sleeve. The other end of the post is formed with a ball portion. A hollow cylindrical collar has an inner threaded surface engageable with the outer threaded surface of the sleeve to rigidly couple the collar to the sleeve. the collar also has a socket portion which cooperates with the ball portion to flexibly connect segments together to form a ball and socket-type joint. In another embodiment, the segment comprises a support member which has a threaded shaft portion and a ball surface portion. The threaded shaft portion is engageable with an inner threaded surface of a ring for rigidly coupling the support member to the ring. The ring in turn has an outer surface at one end which is threadably engageably with a hollow cylindrical sleeve. The other end of the sleeve is formed with a socket portion for engagement with a ball portion of the support member. In yet another embodiment, a secondary rod is slidably inserted in a hollow channel through the center of the segment to provide additional strength. A method for controlling a nuclear reactor utilizing the control rod assembly is also included.

  19. Constraining Effects of Brine Leakage from Carbon Sequestration Sites

    NASA Astrophysics Data System (ADS)

    Wunsch, A.; Navarre-Sitchler, A. K.; McCray, J. E.

    2011-12-01

    States will experience some decrease in yield at a brine/USDW ratio of <0.2, due to high salinity (expressed as TDS). As a stand-alone contaminant, boron that is present in brine may pose the most significant problem in irrigation waters due to low boron tolerance of many crops, particularly fruit.

  20. Particle measurement and brine chemistry at the Salton Sea Deep Well

    SciTech Connect

    Robertus, R.J.; Kindle, C.H.; Sullivan, R.G.; Shannon, D.W.

    1991-09-01

    The Advanced Brine Chemistry Project, a part of the US Department of Energy's Geothermal Energy Program, is addressing operating problems associated with scaling and corrosion at geothermal power plants. Under this project, Pacific Northwest Laboratory conducted a series of tests at the Salton Sea Deep Well, which has one of the highest solids contents in the world. The purpose of the tests was to evaluate monitoring instrumentation under field conditions and relate particulate formation to the brine chemistry. The instrumentation, was evaluated under scaling geothermal conditions using two different principles: ultrasonic reflection and laser light scattering. The following conclusions were drawn from the instrumentation testing and brine chemistry and particulate analyses. (1) Using reflected ultrasonic impulses to detect suspended particles has been demonstrate for on-line application in a geothermal brine with strong scaling tendencies. Advantages over laser light scattering include improved high-temperature durability for the transducer and longer operation with less maintenance. (2) Counting and sizing particles using laser light scattering requires constant maintenance in geothermal applications. (3) Silica is the dominant scale species and appears in amounts orders of magnitude greater than other minor species such as barium sulfate. (4) The silica that formed at high temperatures and short residence times is very gelatinous and difficult to filter out of the brine. (5) Correlation of instrument readings with particle collection data was difficult because conditions on the filter (i.e., temperature, flowrate, and pressure) could not be maintained constant for long enough intervals to obtain comparable information. 5 refs., 27 figs., 2 tabs.

  1. High Pressure Study on High Temperature Superconductors

    NASA Astrophysics Data System (ADS)

    Lin, Jauyn Grace

    In spite of the progress on the understanding of high-temperature superconductivity (HTS), there is still not sufficient evidence to differentiate one theoretical model from the others. In an attempt to relate the crystal structures of high-temperature superconductors (HTS's) to the mechanism of HTS, we have adopted a chemico-physical approach by examining the pressure-effect on the superconducting and transport properties of superconducting compound systems. Without exception, all compounds exhibiting superconductivity above 77 K, the boiling point of liquid nitrogen, are anisotropic structures consisting of layers of CuO_2 , metal element (R's; where R is R being Ca, Y or rare-earth element) and metal-oxide (MO's; where M is Ca, Ba, Sr, Cu, Hg, Tl, Bi or Pb). We have investigated under pressure the electrical and superconducting properties of four highly related systems with different R's, different numbers of MO layers, different numbers of CuO _2 layers and various anion dopings. The specific systems studied were: RBa_2Cu _3O_7 (R = Y, Yb, Tm, Ho, Dy, Gd, Sm and Nd), R_{1 -x}Pr_{x}Ba _2Cu_3O _7 (R = Yb and Dy), Y_2Ba _4Cu_{5 + m} O_{13 + m} (m = 1, 2 and 3), and Tl_2Ba _2Ca_{L-1}Cu _{2L-1}O_ {4 + 2L-delta} (L= 1,2 and 3, and 0 <= delta <= 0.1). We found that: (1) in R-123, R affects T _{c} due to its chemical pressure which, in turn, can lead to a modification in the electronic structure of HTS's, in contrast to the general belief that R is isolated from the superconducting CuO_2 layers and hence has no influence on T _{c}; (2) the absence of superconductivity in PrBa_2Cu_3O _7 may be due to the low carrier concentration and hole-localization, in contrast to the suggestion of pair-breaking; (3) there may exist a common optimal T_{c} for all members of the homologous series Y_2Ba _4Cu_{5 + m} O_{13 + m}, raising the possibility of a similar situation in other compound families; and (4) We have observed a universal T _{c}-behavior for HTS's. We believe that these

  2. High Temperature Solid Lubricant Coating for High Temperature Wear Applications

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher (Inventor); Edmonds, Brian J (Inventor)

    2014-01-01

    A self-lubricating, friction and wear reducing composite useful over a wide temperature range is described herein. The composite includes metal bonded chromium oxide dispersed in a metal binder having a substantial amount of nickel. The composite contains a fluoride of at least one Group I, Group II, or rare earth metal, and optionally a low temperature lubricant metal.

  3. Thermal disconnect for high-temperature batteries

    DOEpatents

    Jungst, Rudolph George; Armijo, James Rudolph; Frear, Darrel Richard

    2000-01-01

    A new type of high temperature thermal disconnect has been developed to protect electrical and mechanical equipment from damage caused by operation at extreme temperatures. These thermal disconnects allow continuous operation at temperatures ranging from 250.degree. C. to 450.degree. C., while rapidly terminating operation at temperatures 50.degree. C. to 150.degree. C. higher than the continuous operating temperature.

  4. 7 CFR 58.422 - Brine tank.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Brine tank. 58.422 Section 58.422 Agriculture....422 Brine tank. The brine tank shall be constructed of suitable non-toxic material and should be resistant to corrosion, pitting or flaking. The brine tank shall be operated so as to assure the brine...

  5. Preliminary Feasibility Testing of the BRIC Brine Water Recovery Concept

    NASA Technical Reports Server (NTRS)

    Callahan, Michael R.; Pensinger, Stuart J.; Pickering, Karen D.

    2012-01-01

    The Brine Residual In-Containment (BRIC) concept is being developed as a new technology to recover water from spacecraft wastewater brines. Such capability is considered critical to closing the water loop and achieving a sustained human presence in space. The intention of the BRIC concept is to increase the robustness and efficiency of the dewatering process by performing drying inside the container used for the final disposal of the residual brine solid. Recent efforts in the development of BRIC have focused on preliminary feasibility testing using a laboratory- assembled pre-prototype unit. Observations of the drying behavior of actual brine solutions processed under BRIC-like conditions has been of particular interest. To date, experiments conducted with three types of analogue spacecraft wastewater brines have confirmed the basic premise behind the proposed application of in-place drying. Specifically, the dried residual mass from these solutions have tended to exhibit characteristics of adhesion and flow that are expected to continue to challenge process stream management designs typically used in spacecraft systems. Yet, these same characteristics may favor the development of capillary- and surface-tension-based approaches currently envisioned as part of an ultimate microgravity-compatible BRIC design. In addition, preliminary feasibility testing of the BRIC pre-prototype confirmed that high rates of water recovery, up to 98% of the available brine water, may be possible while still removing the majority of the brine contaminants from the influent brine stream. These and other early observations from testing are reported.

  6. High Temperature Polyimide Materials in Extreme Temperature Environments

    NASA Technical Reports Server (NTRS)

    Johnson, Theodore F.; Gates, Thomas S.

    2001-01-01

    At the end of the NASA High Speed Research (HSR) Program, NASA Langley Research Center (LaRC) began a program to screen the high-temperature Polymeric Composite Materials (PMCs) characterized by the HSR Durability Program for possible use in Reusable Launch Vehicles (RLVs) operating under extreme temperature conditions. The HSR Program focused on developing material-related technologies to enable a High Speed Civil Transport (HSCT) capable of operating temperatures ranging from 54 C (-65 F) to 177 C (350 F). A high-temperature polymeric resin, PETI-5 was used in the HSR Program to satisfy the requirements for performance and durability for a PMC. For RLVs, it was anticipated that this high temperature material would contribute to reducing the overall weight of a vehicle by eliminating or reducing the thermal protection required to protect the internal structural elements of the vehicle and increasing the structural strain limits. The tests were performed to determine temperature-dependent mechanical and physical proper-ties of IM7/PETI-5 composite over a temperature range from cryogenic temperature -253 C (-423F) to the material's maximum use temperature of 230 C (450 F). This paper presents results from the test program for the temperature-dependent mechanical and physical properties of IM7/PETI-5 composite in the temperature range from -253 C (-423 F) to 27 C (80 F).

  7. High-temperature thermocouples and related methods

    DOEpatents

    Rempe, Joy L.; Knudson, Darrell L.; Condie, Keith G.; Wilkins, S. Curt

    2011-01-18

    A high-temperature thermocouple and methods for fabricating a thermocouple capable of long-term operation in high-temperature, hostile environments without significant signal degradation or shortened thermocouple lifetime due to heat induced brittleness.

  8. High-temperature borehole instrumentation

    SciTech Connect

    Dennis, B.R.; Koczan, S.P.; Stephani, E.L.

    1985-10-01

    A new method of extracting natural heat from the earth's crust was invented at the Los Alamos National Laboratory in 1970. It uses fluid pressures (hydraulic fracturing) to produce cracks that connect two boreholes drilled into hot rock formations of low initial permeability. Pressurized water is then circulated through this connected underground loop to extract heat from the rock and bring it to the surface. The creation of the fracture reservior began with drilling boreholes deep within the Precambrian basement rock at the Fenton Hill Test Site. Hydraulic fracturing, flow testing, and well-completion operations required unique wellbore measurements using downhole instrumentation systems that would survive the very high borehole temperatures, 320/sup 0/C (610/sup 0/F). These instruments were not available in the oil and gas industrial complex, so the Los Alamos National Laboratory initiated an intense program upgrading existing technology where applicable, subcontracting materials and equipment development to industrial manufactures, and using the Laboratory resource to develop the necessary downhole instruments to meet programmatic schedules. 60 refs., 11 figs.

  9. High Temperature Superconducting Underground Cable

    SciTech Connect

    Farrell, Roger, A.

    2010-02-28

    The purpose of this Project was to design, build, install and demonstrate the technical feasibility of an underground high temperature superconducting (HTS) power cable installed between two utility substations. In the first phase two HTS cables, 320 m and 30 m in length, were constructed using 1st generation BSCCO wire. The two 34.5 kV, 800 Arms, 48 MVA sections were connected together using a superconducting joint in an underground vault. In the second phase the 30 m BSCCO cable was replaced by one constructed with 2nd generation YBCO wire. 2nd generation wire is needed for commercialization because of inherent cost and performance benefits. Primary objectives of the Project were to build and operate an HTS cable system which demonstrates significant progress towards commercial progress and addresses real world utility concerns such as installation, maintenance, reliability and compatibility with the existing grid. Four key technical areas addressed were the HTS cable and terminations (where the cable connects to the grid), cryogenic refrigeration system, underground cable-to-cable joint (needed for replacement of cable sections) and cost-effective 2nd generation HTS wire. This was the world’s first installation and operation of an HTS cable underground, between two utility substations as well as the first to demonstrate a cable-to-cable joint, remote monitoring system and 2nd generation HTS.

  10. High-temperature borehole instrumentation

    NASA Astrophysics Data System (ADS)

    Dennis, B. R.; Koczan, S. P.; Stephani, E. L.

    1985-10-01

    A new method of extracting natural heat from the Earth's crust was invented at the Los Alamos National Laboratory in 1970. It uses fluid pressures (hydraulic fracturing) to produce cracks that connect two boreholes drilled into hot rock formations of low initial permeability. Pressurized water is then circulated through this connected underground loop to extract heat from the rock and bring it to the surface. The creation of the fracture reservior began with drilling boreholes deep within the Precambrian basement rock at the Fenton Hill Test Site. Hydraulic fracturing, flow testing, and well-completion operations required unique wellbore measurements using downhole instrumentation systems that would survive the very high borehole temperatures, 320(0)C (610(0)F). These instruments were not available in the oil and gas industrial complex, so the Los Alamos National Laboratory initiated an intense program upgrading existing technology where applicable, subcontracting materials and equipment development to industrial manufactures, and using the Laboratory resources to develop the necessary downhole instruments to meet programmatic schedules.

  11. High temperature suppression of dioxins.

    PubMed

    Zhan, Ming-Xiu; Chen, Tong; Fu, Jian-Ying; Lin, Xiao-Qing; Lu, Sheng-Yong; Li, Xiao-Dong; Yan, Jian-Hua; Buekens, Alfons

    2016-03-01

    Combined Sulphur-Nitrogen inhibitors, such as sewage sludge decomposition gases (SDG), thiourea and amidosulphonic acid have been observed to suppress the de novo synthesis of dioxins effectively. In this study, the inhibition of PCDD/Fs formation from model fly ash was investigated at unusually high temperatures (650 °C and 850 °C), well above the usual range of de novo tests (250-400 °C). At 650 °C it was found that SDG evolving from dried sewage sludge could suppress the formation of 2,3,7,8-substituted PCDD/Fs with high efficiency (90%), both in weight units and in I-TEQ units. Additionally, at 850 °C, three kinds of sulphur-amine or sulphur-ammonium compounds were tested to inhibit dioxins formation during laboratory-scale tests, simulating municipal solid waste incineration. The suppression efficiencies of PCDD/Fs formed through homogeneous gas phase reactions were all above 85% when 3 wt. % of thiourea (98.7%), aminosulphonic acid (96.0%) or ammonium thiosulphate (87.3%) was added. Differences in the ratio of PCDFs/PCDDs, in weight average chlorination level and in the congener distribution of the 17 toxic PCDD/Fs indicated that the three inhibitors tested followed distinct suppression pathways, possibly in relation to their different functional groups of nitrogen. Furthermore, thiourea reduced the (weight) average chlorinated level. In addition, the thermal decomposition of TUA was studied by means of thermogravimetry-fourier transform infrared spectroscopy (TG-FTIR) and the presence of SO2, SO3, NH3 and nitriles (N≡C bonds) was shown in the decomposition gases; these gaseous inhibitors might be the primary dioxins suppressants.

  12. High temperature power electronics for space

    NASA Technical Reports Server (NTRS)

    Hammoud, Ahmad N.; Baumann, Eric D.; Myers, Ira T.; Overton, Eric

    1991-01-01

    A high temperature electronics program at NASA Lewis Research Center focuses on dielectric and insulating materials research, development and testing of high temperature power components, and integration of the developed components and devices into a demonstrable 200 C power system, such as inverter. An overview of the program and a description of the in-house high temperature facilities along with experimental data obtained on high temperature materials are presented.

  13. Chemistry and geothermometry of brine produced from the Salton Sea Scientific drill hole, Imperial Valley, California

    USGS Publications Warehouse

    Thompson, J.M.; Fournier, R.O.

    1988-01-01

    The December 29-30, 1985, flow test of the State 2-14 well, also known as the Salton Sea Scientific drill hole, produced fluid from a depth of 1865-1877 m at a reservoir temperature of 305????5??C. Samples were collected at five different flashing pressures. The brines are Na-Ca-K-Cl-type waters with very high metal and low SO4 and HCO3 contents. Compositions of the flashed brines were normalized relative to the 25??C densities of the solutions, and an ionic charge balance was achieved by adjusting the Na concentration. Calculated Na/K geothermometer temperatures, using equations suggested by different investigators, range from 326?? to 364??C. The Mg/K2 method gives a temperature of about 350??C, Mg/Li2 about 282??, and Na/Li 395??-418??C. -from Authors

  14. High Temperature Chemistry at NASA: Hot Topics

    NASA Technical Reports Server (NTRS)

    Jacobson, Nathan S.

    2014-01-01

    High Temperature issues in aircraft engines Hot section: Ni and Co based Superalloys Oxidation and Corrosion (Durability) at high temperatures. Thermal protection system (TPS) and RCC (Reinforced Carbon-Carbon) on the Space Shuttle Orbiter. High temperatures in other worlds: Planets close to their stars.

  15. Brines and evaporites: analogs for Martian life

    NASA Astrophysics Data System (ADS)

    Mancinelli, R. L.; Fahlen, T. F.; Landheim, R.; Klovstad, M. R.

    2004-01-01

    Data from recent Mars missions suggest that Mars almost certainly had abundant liquid water on its surface at some time in the past. As a result, Mars has emerged as a key solar system target that could have harbored some form of life in the past, and which could perhaps still possess remnants of life in brine-containing permafrost. As Mars lost its atmosphere it became cold and dry. Any remaining water on the surface may have formed saline brine pockets within the permafrost. These brine pockets may either be an "oasis" for an extant Martian biota, or the last refuge of an extinct Martian biota. Eventually, these brine pockets would have dried to form evaporites. Evaporites are deposits that result from the evaporation of saline water, which on earth represent primarily halite (NaCl), gypsum, (CaSO 42H 2O), and anhydrite (CaSO 4). Evaporites that contain bacterial and algal assemblages exist on earth today and are well known in the fossil record. The most likely organism type to survive in a brine or evaporite on earth is a halophile. The objective of this study was to determine the potential of microbes to survive in frozen evaporites. Washed mid-log phase and stationary phase cultures of Haloarcula-G (a species isolated by us during a previous study) and Halobacterium salinarum were either suspended in brine (25% NaCl solution), dried, and then exposed to -20 or -80 °C. For comparison, cultures of Deinococcus radiodurans, Escherichia coli, and Pseudomonas fluorescens were treated similarly, except they were resuspended in 0.5% NaCl solution. Also, to mimic a brine pocket samples of washed mid-log phase cells of each organism were placed in an aqueous solution of 25% NaCl, or in their respective nutrient medium containing 25% NaCl. Periodically, samples of the cells were removed and tested for survival. Data from these experiments suggest that halophiles survive better than non-halophiles under low temperature conditions. These observations would suggest that

  16. Brine migration resulting from pressure increases in a layered subsurface system

    NASA Astrophysics Data System (ADS)

    Delfs, Jens-Olaf; Nordbeck, Johannes; Bauer, Sebastian

    2016-04-01

    Brine originating from the deep subsurface impairs parts of the freshwater resources in the North German Basin. Some of the deep porous formations (esp. Trias and Jurassic) exhibit considerable storage capacities for waste fluids (CO2, brine from oil production or cavern leaching), raising concerns among water providers that this type of deep subsurface utilization might impair drinking water supplies. On the one hand, overpressures induced by fluid injections and the geothermal gradient support brine migration from deep into shallow formations. On the other hand, the rising brine is denser than the surrounding less-saline formation waters and, therefore, tends to settle down. Aim of this work is to investigate the conditions under which pressurized formation brine from deep formations can reach shallow freshwater resources. Especially, the role of intermediate porous formations between the storage formation and the groundwater is studied. For this, complex thermohaline simulations using a coupled numerical process model are necessary and performed in this study, in which fluid density depends on fluid pressure, temperature and salt content and the governing partial differential equations are coupled. The model setup is 2D and contains a hypothetic series of aquifers and barriers, each with a thickness of 200 m. Formation pressure is increased at depths of about 2000 m in proximity to a salt wall and a permeable fault. The domain size reaches up to tens of kilometers horizontally to the salt wall. The fault connects the injection formation and the freshwater aquifer such that conditions can be considered as extremely favorable for induced brine migration (worst case scenarios). Brine, heat, and salt fluxes are quantified with reference to hydraulic permeabilities, storage capacities (in terms of domain size), initial salt and heat distribution, and operation pressures. The simulations reveal the development of a stagnation point in the fault region in each

  17. Brine migration resulting from pressure increases in a layered subsurface system

    NASA Astrophysics Data System (ADS)

    Delfs, Jens-Olaf; Nordbeck, Johannes; Bauer, Sebastian

    2016-04-01

    Brine originating from the deep subsurface impairs parts of the freshwater resources in the North German Basin. Some of the deep porous formations (esp. Trias and Jurassic) exhibit considerable storage capacities for waste fluids (CO2, brine from oil production or cavern leaching), raising concerns among water providers that this type of deep subsurface utilization might impair drinking water supplies. On the one hand, overpressures induced by fluid injections and the geothermal gradient support brine migration from deep into shallow formations. On the other hand, the rising brine is denser than the surrounding less-saline formation waters and, therefore, tends to settle down. Aim of this work is to investigate the conditions under which pressurized formation brine from deep formations can reach shallow freshwater resources. Especially, the role of intermediate porous formations between the storage formation and the groundwater is studied. For this, complex thermohaline simulations using a coupled numerical process model are necessary and performed in this study, in which fluid density depends on fluid pressure, temperature and salt content and the governing partial differential equations are coupled. The model setup is 2D and contains a hypothetic series of aquifers and barriers, each with a thickness of 200 m. Formation pressure is increased at depths of about 2000 m in proximity to a salt wall and a permeable fault. The domain size reaches up to tens of kilometers horizontally to the salt wall. The fault connects the injection formation and the freshwater aquifer such that conditions can be considered as extremely favorable for induced brine migration (worst case scenarios). Brine, heat, and salt fluxes are quantified with reference to hydraulic permeabilities, storage capacities (in terms of domain size), initial salt and heat distribution, and operation pressures. The simulations reveal the development of a stagnation point in the fault region in each

  18. Nature and origin of RSL: Spectroscopy and detectability of liquid brines in the near-infrared

    NASA Astrophysics Data System (ADS)

    Masse, Marion; Beck, Pierre; Schmitt, Bernard; Pommerol, Antoine; McEwen, Alfred; Chevrier, Vincent; Brissaud, Olivier

    2013-04-01

    If water has likely flowed on Mars in its early history, the current presence of liquid water is debatable. However, some recently discovered fea-tures named "Recurrent Slope Lineae" (RSL) suggest that superficial liquid can occur on present day Mars in a transient state [McEwen et al., 2011]. RSL are dark (up to 40% darker than the surrounding areas), narrow (0.5-5 m) and are mostly found in the southern mid-latitudes. Repeated MRO/HiRISE images reveal that they appear and grow during warm seasons and fade and disappear during cold seasons. They develop on steep slopes (25°-40°), favoring equator-facing slopes, times and places with peak temperatures of ~250-300K. The most likely formation process of RSL involves the presence of liquid brines near the surface. Brines are more stable on Mars than pure water [e.g. Chevrier et al., 2009] because salts can depress the freezing point of water by up to 70 K. However, this hypothesis suffers from the lack of clear identification of brines with the high resolution CRISM spectra. The mineralogical characterization of RSL is challenging because RSL are much smaller than the ~18 m pixel scale of CRISM data but spectral features diagnostic of water or brines [Hanley et al., 2010] are not observable even on the largest RSL. The goal of our study is to reproduce with laboratory experiments some hydration and dehydration cycles of different kind of brines mixed with basaltic soil. These experiments aim to understand the spectroscopic behavior of brines during these processes and to determine the diagnostic spectral features that we can expected to find for Martian RSL. We found that, if the surface displays a low albedo from the beginning of the hydration to the end of the dehydration, diagnostic brines absorption bands are only observed when the liquid film is formed. This is consistent with our current RSL observations. In the future, we need to acquire some new CRISM data when the formation of liquid brines is the most

  19. Recovery Act: Molecular Simulation of Dissolved Inorganic Carbons for Underground Brine CO2 Sequestration

    SciTech Connect

    Goddard, William

    2012-11-30

    To further our understanding and develop the method for measuring the DICs under geological sequestration conditions, we studied the infrared spectra of DICs under high pressure and temperature conditions. First principles simulations of DICs in brine conditions were performed using a highly optimized ReaxFF-DIC forcefield. The thermodynamics stability of each species were determined using the 2PT method, and shown to be consistent with the Reax simulations. More importantly, we have presented the IR spectra of DIC in real brine conditions as a function of temperature and pressure. At near earth conditions, we find a breaking of the O-C-O bending modes into asymmetric and symmetric modes, separated by 100cm{sup -1} at 400K and 5 GPa. These results can now be used to calibrate FTIR laser measurements.

  20. High-Sensitivity Temperature Measurement

    ERIC Educational Resources Information Center

    Leadstone, G. S.

    1978-01-01

    Describes a method of measuring small temperature differences that amount to a .01K, using an arrangement of a copper-constantan thermocouple, a microamplifier and a galvanometer, as an indirect way of measuring heat energy. (GA)

  1. Measurement of thermodynamic temperature of high temperature fixed points

    SciTech Connect

    Gavrilov, V. R.; Khlevnoy, B. B.; Otryaskin, D. A.; Grigorieva, I. A.; Samoylov, M. L.; Sapritsky, V. I.

    2013-09-11

    The paper is devoted to VNIIOFI's measurements of thermodynamic temperature of the high temperature fixed points Co-C, Pt-C and Re-C within the scope of the international project coordinated by the Consultative Committee for Thermometry working group 5 'Radiation Thermometry'. The melting temperatures of the fixed points were measured by a radiance mode radiation thermometer calibrated against a filter radiometer with known irradiance spectral responsivity via a high temperature black body. This paper describes the facility used for the measurements, the results and estimated uncertainties.

  2. Biochemical solubilization of toxic salts from residual geothermal brines and waste waters

    DOEpatents

    Premuzic, Eugene T.; Lin, Mow S.

    1994-11-22

    A method of solubilizing metal salts such as metal sulfides in a geothermal sludge using mutant Thiobacilli selected for their ability to metabolize metal salts at high temperature is disclosed, The method includes the introduction of mutated Thiobacillus ferrooxidans and Thiobacillus thiooxidans to a geothermal sludge or brine. The microorganisms catalyze the solubilization of metal salts, For instance, in the case of metal sulfides, the microorganisms catalyze the solubilization to form soluble metal sulfates.

  3. Biochemical solubilization of toxic salts from residual geothermal brines and waste waters

    DOEpatents

    Premuzic, E.T.; Lin, M.S.

    1994-11-22

    A method of solubilizing metal salts such as metal sulfides in a geothermal sludge using mutant Thiobacilli selected for their ability to metabolize metal salts at high temperature is disclosed. The method includes the introduction of mutated Thiobacillus ferrooxidans and Thiobacillus thiooxidans to a geothermal sludge or brine. The microorganisms catalyze the solubilization of metal salts. For instance, in the case of metal sulfides, the microorganisms catalyze the solubilization to form soluble metal sulfates. 54 figs.

  4. High Temperature Filler for Tile Gaps

    NASA Technical Reports Server (NTRS)

    Holt, J. W.; Wang, D. S.

    1983-01-01

    Gaps between ceramic tiles filled with ceramic-coated fabric that withstands temperatures as high as 2,000 degrees F (1,300 degrees C). Reusable high-temperature gap filler is made of fabric coated with ceramic slurry and bonded in place with room-temperature-vulcanized adhesive. Procedure used in kilns and furnaces.

  5. High temperature superconducting fault current limiter

    DOEpatents

    Hull, John R.

    1997-01-01

    A fault current limiter (10) for an electrical circuit (14). The fault current limiter (10) includes a high temperature superconductor (12) in the electrical circuit (14). The high temperature superconductor (12) is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter (10).

  6. High temperature superconducting fault current limiter

    DOEpatents

    Hull, J.R.

    1997-02-04

    A fault current limiter for an electrical circuit is disclosed. The fault current limiter includes a high temperature superconductor in the electrical circuit. The high temperature superconductor is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter. 15 figs.

  7. Natural Oxidation of Bromide to Bromine in Evaporated Dead Sea Brines

    NASA Astrophysics Data System (ADS)

    Gavrieli, Ittai; Golan, Rotem; Lazar, Boaz; Baer, Gidi; Zakon, Yevgeni; Ganor, Jiwchar

    2016-04-01

    Highly evaporated Dead Sea brines are found in isolated sinkholes along the Dead Sea. Many of these brines reach densities of over 1.3 kg/L and pH<5 and are the product of evaporation of Dead Sea brine that drain into the sinkholes. The low pH and the reddish to brownish hue of these brines were an enigma until recently. Despite the rather high total alkalinity (TA) of the Dead Sea (3.826 mmol/kg) the pH of the Dead Sea brine is known to be slightly acidic with a value of ~6.3. In comparison, seawater with the same alkalinity would have a pH value well above 8.3, meaning that H+ activity is 100 fold lower than that of Dead Sea brine. In the present work we assess the apparent dissociation constant value of boric acid (K`B) for the Dead Sea brine and use it to explain the brine's low pH value. We then show that pH decreases further as the brine evaporates and salinity increases. Finally we explain the reddish hue of the hypersaline brines in the sinkholes as due to the presence of dissolved bromine. The latter is the product of oxidation of dissolved bromide, a process that is enabled by the low pH of the hypersaline brines and their high bromide concentration.

  8. High temperature ceramic interface study

    NASA Technical Reports Server (NTRS)

    Lindberg, L. J.

    1984-01-01

    Monolithic SiC and Si3N4 are susceptible to contact stress damage at static and sliding interfaces. Transformation-toughened zirconia (TTZ) was evaluated under sliding contact conditions to determine if the higher material fracture toughness would reduce the susceptibility to contact stress damage. Contact stress tests were conducted on four commercially available TTZ materials at normal loads ranging from 0.455 to 22.7 kg (1 to 50 pounds) at temperatures ranging from room temperature to 1204C (2200 F). Static and dynamic friction were measured as a function of temperature. Flexural strength measurements after these tests determined that the contact stress exposure did not reduce the strength of TTZ at contact loads of 0.455, 4.55, and 11.3 kg (1, 10, and 25 pounds). Prior testing with the lower toughness SiC and Si3N4 materials resulted in a substantial strength reduction at loads of only 4.55 and 11.3 kg (10 and 25 pounds). An increase in material toughness appears to improve ceramic material resistance to contact stress damage. Baseline material flexure strength was established and the stress rupture capability of TTZ was evaluated. Stress rupture tests determined that TTZ materials are susceptible to deformation due to creep and that aging of TTZ materials at elevated temperatures results in a reduction of material strength.

  9. Deep Trek High Temperature Electronics Project

    SciTech Connect

    Bruce Ohme

    2007-07-31

    This report summarizes technical progress achieved during the cooperative research agreement between Honeywell and U.S. Department of Energy to develop high-temperature electronics. Objects of this development included Silicon-on-Insulator (SOI) wafer process development for high temperature, supporting design tools and libraries, and high temperature integrated circuit component development including FPGA, EEPROM, high-resolution A-to-D converter, and a precision amplifier.

  10. High temperature tensile testing of ceramic composites

    NASA Technical Reports Server (NTRS)

    Gyekenyesi, John Z.; Hemann, John H.

    1988-01-01

    The various components of a high temperature tensile testing system are evaluated. The objective is the high temperature tensile testing of SiC fiber reinforced reaction bonded Si3N4 specimens at test temperatures up to 1650 C (3000 F). Testing is to be conducted in inert gases and air. Gripping fixtures, specimen configurations, furnaces, optical strain measuring systems, and temperature measurement techniques are reviewed. Advantages and disadvantages of the various techniques are also noted.

  11. Dynamic, High-Temperature, Flexible Seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Sirocky, Paul J.

    1989-01-01

    New seal consists of multiple plies of braided ceramic sleeves filled with small ceramic balls. Innermost braided sleeve supported by high-temperature-wire-mesh sleeve that provides both springback and preload capabilities. Ceramic balls reduce effect of relatively high porosity of braided ceramic sleeves by acting as labyrinth flow path for gases and thereby greatly increasing pressure gradient seal can sustain. Dynamic, high-temperature, flexible seal employed in hypersonic engines, two-dimensional convergent/divergent and vectorized-thrust exhaust nozzles, reentry vehicle airframes, rocket-motor casings, high-temperature furnaces, and any application requiring non-asbestos high-temperature gaskets.

  12. Determination of extremely high pressure tolerance of brine shrimp larvae by using a new pressure chamber system.

    PubMed

    Seo, Mihye; Koyama, Sumihiro; Toyofuku, Takashi; Kojima, Shigeaki; Watanabe, Hiromi

    2013-11-01

    Hydrostatic pressure is the only one of a range of environmental parameters (water temperature, salinity, light availability, and so on) that increases in proportion with depth. Pressure tolerance is therefore essential to understand the foundation of populations and current diversity of faunal compositions at various depths. In the present study, we used a newly developed pressure chamber system to examine changes in larval activity of the salt-lake crustacean, Artemia franciscana, in response to a range of hydrostatic pressures. We showed that A. franciscana larvae were able to survive for a short period at pressures of ≤ 60 MPa (approximately equal to the pressure of 6000 m deep). At a pressure of > 20 MPa, larval motor ability was suppressed, but not lost. Meanwhile, at a pressure of > 40 MPa, some of the larval motor ability was lost without recovery after decompression. For all experiments, discordance of movement and timing between right and left appendages, was observed at pressures of > 20 MPa. Our results indicate that the limit of pressure for sustaining active behavior of A. franciscana larvae is ∼20 MPa, whereas the limit of pressure for survival is within the range 30-60 MPa. Thus, members of the genus Artemia possess the ability to resist a higher range of pressures than their natural habitat depth. Our findings demonstrated an example of an organism capable of invading deeper environment in terms of physical pressure tolerance, and indicate the need and importance of pressure study as an experimental method. PMID:24224473

  13. Cryogenic brines as a diagenetic fluid: using clumped isotopes to reconstruct the cementation history of sediments in the ANDRILL 2A core

    NASA Astrophysics Data System (ADS)

    Staudigel, P. T.; Dunham, D.; Fielding, C. R.; Frank, T. D.; Swart, P. K.

    2015-12-01

    The ANDRILL 2A core contains a succession of Neogene glaciomarine deposits, cemented by up to 20 wt% carbonate. Isotopic analysis of the cements yielded extremely negative d18O values, indicating either formation from isotopically negative fluids or at extremely high temperature. In outcrop, such values could be interpreted as being the result of meteoric diagenesis, but the lack of any exposure horizons in the core precludes such an interpretation. A previous study of the pore fluids described a brine below 200m, with an extremely negative δ18O value (c. -10‰), probably formed by batch-freezing seawater on the continental margin. The present study integrates ∆47­ values of the cements with traditional approaches to further assess the nature of diagenetic fluids and processes. Isotopic data suggest three sources of carbonate: marine, methane reducing, and the aforementioned brines. Marine carbonate indicates δ13C and water δ18O within the range typical of seawater (c. -1‰), whereas the cryogenic brines show more negative values. A few samples exhibited extremely low δ13C values, the lowest below -25‰; the only feasible source for these cements would be the oxidation of methane. The shallow cements' signatures diminish with depth as cryogenic brines begin to dominate the isotopic signal. Biogenic materials show an increased influence of this brine at depth, the deepest buried shells are isotopically indistinguishable from adjacent cements. These analyses show that these cryogenic brines play a major role in the diagenetic history of this site. Clumped isotopic results support previous interpretations using traditional methods, which have identified cryogenic brine as a major cementing agent in the subsurface of Southern McMurdo Sound. Because cryogenic brines have likely formed throughout Earth history, results have the potential to change the way diagenesis is evaluated in sedimentary successions that formed in polar environments.

  14. High temperature silicon carbide impregnated insulating fabrics

    NASA Technical Reports Server (NTRS)

    Schomburg, C.; Dotts, R. L. (Inventor)

    1982-01-01

    High temperature insulating articles having improved performance characteristics are described. The articles comprise fabrics of closely woven refractory or heat resistant fibers having particles of silicon carbide dispersed at least partially through the fabric and bonded to the fibers with an emulsifiable polyethylene wax. Such articles exhibit significantly increased high temperature emittance characteristics and an improved retention of integrity and flexibility after prolonged exposure to high temperature.

  15. Molds in Brined Cucumbers: Cause of Softening During Air-Purging of Fermentations †

    PubMed Central

    Costilow, Ralph N.; Gates, Karen; Lacy, Melvyn L.

    1980-01-01

    Softening of cucumbers in fermentations purged at high air-flow rates was caused by molds growing in the brined cucumbers, not in the brine. This conclusion is based on the following results: (i) no microorganisms were isolated in significant numbers from brines that caused softening of pasteurized brined cucumbers, (ii) no pectinolytic enzyme activities were produced in cucumber brines in the absence of cucumbers, (iii) the pickles in some air-purged fermentations became very soft without the appearance of any pectinolytic enzyme activity in the brine, (iv) mold hyphae were consistently observed in tissues of soft pickles, (v) molds consistently developed in cultures of slices of surface sterilized cucumbers taken from fermentations in which soft pickles were subsequently found, and (vi) molds belonging to the genera Alternaria, Fusarium, and Mucor isolated from slices all softened pasteurized brined cucumbers. Images PMID:16345619

  16. Fermentation of cucumbers brined with calcium chloride instead of sodium chloride.

    PubMed

    McFeeters, Roger F; Pérez-Díaz, Ilenys

    2010-04-01

    Waste water containing high levels of NaCl from cucumber fermentation tank yards is a continuing problem for the pickled vegetable industry. A major reduction in waste salt could be achieved if NaCl were eliminated from the cucumber fermentation process. The objectives of this project were to ferment cucumbers in brine containing CaCl(2) as the only salt, to determine the course of fermentation metabolism in the absence of NaCl, and to compare firmness retention of cucumbers fermented in CaCl(2) brine during subsequent storage compared to cucumbers fermented in brines containing both NaCl and CaCl(2) at concentrations typically used in commercial fermentations. The major metabolite changes during fermentation without NaCl were conversion of sugars in the fresh cucumbers primarily to lactic acid which caused pH to decrease to less than 3.5. This is the same pattern that occurs when cucumbers are fermented with NaCl as the major brining salt. Lactic acid concentration and pH were stable during storage and there was no detectable production of propionic acid or butyric acid that would indicate growth of spoilage bacteria. Firmness retention in cucumbers fermented with 100 to 300 mM CaCl(2) during storage at a high temperature (45 degrees C) was not significantly different from that obtained in fermented cucumbers with 1.03 M NaCl and 40 mM CaCl(2). In closed jars, cucumber fermentations with and without NaCl in the fermentation brine were similar both in the chemical changes caused by the fermentative microorganisms and in the retention of firmness in the fermented cucumbers.

  17. Advanced high-temperature batteries

    NASA Technical Reports Server (NTRS)

    Nelson, P. A.

    1989-01-01

    Recent results for Li-Al/FeS2 cells and bipolar battery design have shown the possibility of achieving high specific energy (210 Wh/kg) and high specific power (239 W/kg) at the cell level for an electric vehicle application. Outstanding performance is also projected for sodium/metal chloride cells having large electrolyte areas and thin positive electrodes.

  18. An Experimental Study of CO2-Brine Relative Permeability in Sandstone

    NASA Astrophysics Data System (ADS)

    Chen, X.; DiCarlo, D. A.

    2013-12-01

    Accurate determinations of CO2-brine relative permeability are important for modeling potential CO2 storage scenarios. The most common assumption is that CO2-brine relative permeability is likely to be similar to oil-brine relative permeability for water-wet rocks. But recent measurements of CO2-brine relative permeability have differed greatly from oil-brine relative permeability; particularly, the measurements show a very low CO2 end point relative permeability (kr,CO2=0.1~0.2) and a relatively high residual water saturation (Swr>0.4) ( Lee et al. 2010, Zuo et al. 2012, Akbarabadi et al. 2013 and etc.). It has been hypothesized that the differences are related to CO2-brine having a different contact angle from oil-brine. In this study, we hypothesize that the differences are caused by large capillary end effects resulted from the very low CO2 viscosity. We conduct steady-state CO2-brine flow experiments in 2-foot-long and 2.8-inch-diamter Berea sandstone cores at 20 °C and 1500 psi. Four pressure taps drilled on a core allow both the total pressure drop and that across five individual sections to be measured. Three experiments, two drainage and one imbibition, have been conducted so far. Our results show: (1) The relative permeability to both brine and CO2 of the last section (downstream, 15 cm long) is significantly smaller than that of any of the middle three sections. This testifies that the capillary end effect makes the relative permeability under-measured at the end of a core. (2) The values of the middle three sections are very close to each other, which indicate the middle part of our core is free of capillary end effect. (3) The CO2 end point relative permeability is 0.3~0.5, which is much higher than the recent measurements. (4) The brine end point relative permeability during imbibition is about 0.08, which is close to literature data. Reference: Lee, Y.S, Kim, K. H. and Lee, T.H. et al. Analysis of CO2 Endpoint Relative Permeability and Injectivity

  19. Investigations into High Temperature Components and Packaging

    SciTech Connect

    Marlino, L.D.; Seiber, L.E.; Scudiere, M.B.; M.S. Chinthavali, M.S.; McCluskey, F.P.

    2007-12-31

    The purpose of this report is to document the work that was performed at the Oak Ridge National Laboratory (ORNL) in support of the development of high temperature power electronics and components with monies remaining from the Semikron High Temperature Inverter Project managed by the National Energy Technology Laboratory (NETL). High temperature electronic components are needed to allow inverters to operate in more extreme operating conditions as required in advanced traction drive applications. The trend to try to eliminate secondary cooling loops and utilize the internal combustion (IC) cooling system, which operates with approximately 105 C water/ethylene glycol coolant at the output of the radiator, is necessary to further reduce vehicle costs and weight. The activity documented in this report includes development and testing of high temperature components, activities in support of high temperature testing, an assessment of several component packaging methods, and how elevated operating temperatures would impact their reliability. This report is organized with testing of new high temperature capacitors in Section 2 and testing of new 150 C junction temperature trench insulated gate bipolar transistor (IGBTs) in Section 3. Section 4 addresses some operational OPAL-GT information, which was necessary for developing module level tests. Section 5 summarizes calibration of equipment needed for the high temperature testing. Section 6 details some additional work that was funded on silicon carbide (SiC) device testing for high temperature use, and Section 7 is the complete text of a report funded from this effort summarizing packaging methods and their reliability issues for use in high temperature power electronics. Components were tested to evaluate the performance characteristics of the component at different operating temperatures. The temperature of the component is determined by the ambient temperature (i.e., temperature surrounding the device) plus the

  20. Alteration Behavior of High Burnup Spent Fuel in Salt Brine Under Hydrogen Overpressure and in Presence of Bromide

    SciTech Connect

    Loida, Andreas; Metz, Volker; Kienzler, Bernhard

    2007-07-01

    Recent studies have shown that in the presence of H2 overpressure, which forms due to the corrosion of the Fe based container, the dissolution rate of the spent fuel matrix is slowed down by a factor of about 10, associated with a distinct decrease of concentrations of important radionuclides. However, in a natural salt environment as well as in geological formations with chloride rich groundwater the presence of radiation chemically active impurities such as bromide must be taken in consideration. Bromide is known to react with {beta}/{gamma} radiolysis products, thus counteracting the protective H{sub 2} effect. In the present experiments using high burnup spent fuel, it is observed that during 212 days the matrix dissolution rate was enhanced by a factor of about 10 in the presence of up to 10{sup -3} M bromide and 3.2 bar H{sub 2} overpressure. However, concentrations of matrix bound actinides were found at the same level or below as found under identical conditions, but in the absence of bromide. In the long-term it is expected that the effect of bromide becomes less important, because the decrease of {beta}/{gamma}-activity results in a decrease of oxidative radicals, which react with bromide, while a-activity will dominate the radiation field. (authors)

  1. Development of high temperature strain gages

    NASA Technical Reports Server (NTRS)

    Lemcoe, M. M.

    1973-01-01

    High temperature electric resistance wire strain gages were developed and evaluated for use at temperatures exceeding 922 K (1200 F). A special high temperature strain gage alloy (Fe-25Cr-7.5A1), designated BCL-3, was used to fabricate the gages. Pertinent gage characteristics were determined at temperatures up to 1255 K (1800 F). The results of the evaluation were reported in graphical and tabular form. It was concluded that the gages will perform satisfactorily at temperatures to at least 1089 K (1500 F) for at least one hour.

  2. Nuclear fuels for very high temperature applications

    SciTech Connect

    Lundberg, L.B.; Hobbins, R.R.

    1992-01-01

    The success of the development of nuclear thermal propulsion devices and thermionic space nuclear power generation systems depends on the successful utilization of nuclear fuel materials at temperatures in the range 2000 to 3500 K. Problems associated with the utilization of uranium bearing fuel materials at these very high temperatures while maintaining them in the solid state for the required operating times are addressed. The critical issues addressed include evaporation, melting, reactor neutron spectrum, high temperature chemical stability, fabrication, fission induced swelling, fission product release, high temperature creep, thermal shock resistance, and fuel density, both mass and fissile atom. Candidate fuel materials for this temperature range are based on UO{sub 2} or uranium carbides. Evaporation suppression, such as a sealed cladding, is required for either fuel base. Nuclear performance data needed for design are sparse for all candidate fuel forms in this temperature range, especially at the higher temperatures.

  3. Nuclear fuels for very high temperature applications

    SciTech Connect

    Lundberg, L.B.; Hobbins, R.R.

    1992-08-01

    The success of the development of nuclear thermal propulsion devices and thermionic space nuclear power generation systems depends on the successful utilization of nuclear fuel materials at temperatures in the range 2000 to 3500 K. Problems associated with the utilization of uranium bearing fuel materials at these very high temperatures while maintaining them in the solid state for the required operating times are addressed. The critical issues addressed include evaporation, melting, reactor neutron spectrum, high temperature chemical stability, fabrication, fission induced swelling, fission product release, high temperature creep, thermal shock resistance, and fuel density, both mass and fissile atom. Candidate fuel materials for this temperature range are based on UO{sub 2} or uranium carbides. Evaporation suppression, such as a sealed cladding, is required for either fuel base. Nuclear performance data needed for design are sparse for all candidate fuel forms in this temperature range, especially at the higher temperatures.

  4. Corrosion Resistant Coatings for High Temperature Applications

    SciTech Connect

    Besman, T.M.; Cooley, K.M.; Haynes, J.A.; Lee, W.Y.; Vaubert, V.M.

    1998-12-01

    Efforts to increase efficiency of energy conversion devices have required their operation at ever higher temperatures. This will force the substitution of higher-temperature structural ceramics for lower temperature materials, largely metals. Yet, many of these ceramics will require protection from high temperature corrosion caused by combustion gases, atmospheric contaminants, or the operating medium. This paper discusses examples of the initial development of such coatings and materials for potential application in combustion, aluminum smelting, and other harsh environments.

  5. Spin Hall magnetoresistance at high temperatures

    SciTech Connect

    Uchida, Ken-ichi; Qiu, Zhiyong; Kikkawa, Takashi; Iguchi, Ryo; Saitoh, Eiji

    2015-02-02

    The temperature dependence of spin Hall magnetoresistance (SMR) in Pt/Y{sub 3}Fe{sub 5}O{sub 12} (YIG) bilayer films has been investigated in a high temperature range from room temperature to near the Curie temperature of YIG. The experimental results show that the magnitude of the magnetoresistance ratio induced by the SMR monotonically decreases with increasing the temperature and almost disappears near the Curie temperature. We found that, near the Curie temperature, the temperature dependence of the SMR in the Pt/YIG film is steeper than that of a magnetization curve of the YIG; the critical exponent of the magnetoresistance ratio is estimated to be 0.9. This critical behavior of the SMR is attributed mainly to the temperature dependence of the spin-mixing conductance at the Pt/YIG interface.

  6. Borehole Stability in High-Temperature Formations

    NASA Astrophysics Data System (ADS)

    Yan, Chuanliang; Deng, Jingen; Yu, Baohua; Li, Wenliang; Chen, Zijian; Hu, Lianbo; Li, Yang

    2014-11-01

    In oil and gas drilling or geothermal well drilling, the temperature difference between the drilling fluid and formation will lead to an apparent temperature change around the borehole, which will influence the stress state around the borehole and tend to cause borehole instability in high geothermal gradient formations. The thermal effect is usually not considered as a factor in most of the conventional borehole stability models. In this research, in order to solve the borehole instability in high-temperature formations, a calculation model of the temperature field around the borehole during drilling is established. The effects of drilling fluid circulation, drilling fluid density, and mud displacement on the temperature field are analyzed. Besides these effects, the effect of temperature change on the stress around the borehole is analyzed based on thermoelasticity theory. In addition, the relationships between temperature and strength of four types of rocks are respectively established based on experimental results, and thermal expansion coefficients are also tested. On this basis, a borehole stability model is established considering thermal effects and the effect of temperature change on borehole stability is also analyzed. The results show that the fracture pressure and collapse pressure will both increase as the temperature of borehole rises, and vice versa. The fracture pressure is more sensitive to temperature. Temperature has different effects on collapse pressures due to different lithological characters; however, the variation of fracture pressure is unrelated to lithology. The research results can provide a reference for the design of drilling fluid density in high-temperature wells.

  7. Recrystallization of high temperature superconductors

    SciTech Connect

    Kouzoudis, D.

    1996-05-09

    Currently one of the most widely used high {Tc} superconductors is the Bi-based compounds Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub z} and Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub z} (known as BSCCO 2212 and 2223 compounds) with {Tc} values of about 85 K and 110 K respectively. Lengths of high performance conductors ranging from 100 to 1000 m long are routinely fabricated and some test magnets have been wound. An additional difficulty here is that although Bi-2212 and Bi-2223 phases exist over a wide range of stoichiometries, neither has been prepared in phase-pure form. So far the most successful method of constructing reliable and robust wires or tapes is the so called powder-in-tube (PIT) technique [1, 2, 3, 4, 5, 6, 7] in which oxide powder of the appropriate stoichiometry and phase content is placed inside a metal tube, deformed into the desired geometry (round wire or flat tape), and annealed to produce the desired superconducting properties. Intermediate anneals are often incorporated between successive deformation steps. Silver is the metal used in this process because it is the most compatible with the reacting phase. In all of the commercial processes for BSCCO, Ag seems to play a special catalytic role promoting the growth of high performance aligned grains that grow in the first few micrometers near the Ag/BSCCO interface. Adjacent to the Ag, the grain alignment is more perfect and the current density is higher than in the center of the tape. It is known that Ag lowers the melting point of several of the phases but the detailed mechanism for growth of these high performance grains is not clearly understood. The purpose of this work is to study the nucleation and growth of the high performance material at this interface.

  8. High temperature resistant cermet and ceramic compositions

    NASA Technical Reports Server (NTRS)

    Phillips, W. M. (Inventor)

    1978-01-01

    Cermet compositions having high temperature oxidation resistance, high hardness and high abrasion and wear resistance, and particularly adapted for production of high temperature resistant cermet insulator bodies are presented. The compositions are comprised of a sintered body of particles of a high temperature resistant metal or metal alloy, preferably molybdenum or tungsten particles, dispersed in and bonded to a solid solution formed of aluminum oxide and silicon nitride, and particularly a ternary solid solution formed of a mixture of aluminum oxide, silicon nitride and aluminum nitride. Also disclosed are novel ceramic compositions comprising a sintered solid solution of aluminum oxide, silicon nitride and aluminum nitride.

  9. Copper Alloy For High-Temperature Uses

    NASA Technical Reports Server (NTRS)

    Dreshfield, Robert L.; Ellis, David L.; Michal, Gary

    1994-01-01

    Alloy of Cu/8Cr/4Nb (numbers indicate parts by atom percent) improved over older high-temperature copper-based alloys in that it offers enhanced high temperature strength, resistance to creep, and ductility while retaining most of thermal conductivity of pure copper; in addition, alloy does not become embrittled upon exposure to hydrogen at temperatures as high as 705 degrees C. Designed for use in presence of high heat fluxes and active cooling; for example, in heat exchangers in advanced aircraft and spacecraft engines, and other high-temperature applications in which there is need for such material. High conductivity and hardness of alloy exploited in welding electrodes and in high-voltage and high-current switches and other applications in which wear poses design problem.

  10. Membrane Cells for Brine Electrolysis.

    ERIC Educational Resources Information Center

    Tingle, M.

    1982-01-01

    Membrane cells were developed as alternatives to mercury and diaphragm cells for the electrolysis of brine. Compares the three types of cells, focusing on the advantages and disadvantages of membrane cells. (JN)

  11. Silicon carbide, a high temperature semiconductor

    NASA Technical Reports Server (NTRS)

    Powell, J. A.

    1983-01-01

    Electronic applications are described that would benefit from the availability of high temperature semiconductor devices. Comparisons are made among potential materials for these devices and the problems of each are discussed. Recent progress in developing silicon carbide as a high temperature semiconductor is described.

  12. Evaluation of high temperature polymers

    NASA Technical Reports Server (NTRS)

    Jayaraj, K.; Dorogy, W.; Farrell, B.; Landrau, N.

    1995-01-01

    The purpose of this paper is to identify and develop arc-track resistant insulation materials that can operate reliably at 300 C. In the first phase, high performance polymers are evaluated based on structure, thermal stability and electrical properties. Next, the polymers are ranked according to performance and experimental characterization. Then, experimental evaluations in wire configuration are conducted. And selection is made based on performance and commerical potential.

  13. High temperature superconductors for computer interconnect applications

    SciTech Connect

    Nilsson, B.J.L.

    1994-12-31

    High temperature superconductors, because of their extremely low loss at high frequencies and their high current handling capability, have the potential for use in computer interconnect boards. They offer the potential advantages of high interconnect density, reduced interconnect delays, and higher data rate. Because silicon CMOS circuits dramatically improve in performance at low temperatures, cooled computers may become attractive in the future to capture both the improved interconnect and circuit benefits.

  14. High-temperature Solar Cell Development

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Merritt, Danielle; Raffaelle, Ryne P.; Scheiman, David

    2005-01-01

    The vast majority of space probes to date have relied upon photovoltaic power generation. If future missions designed to probe environments close to the sun (Figure 1) will be able to use such power generation, solar cells that can function at high temperatures, under high light intensity, and high radiation conditions must be developed. The significant problem is that solar cells lose performance at high temperatures.

  15. High temperature solar selective coatings

    DOEpatents

    Kennedy, Cheryl E

    2014-11-25

    Improved solar collectors (40) comprising glass tubing (42) attached to bellows (44) by airtight seals (56) enclose solar absorber tubes (50) inside an annular evacuated space (54. The exterior surfaces of the solar absorber tubes (50) are coated with improved solar selective coatings {48} which provide higher absorbance, lower emittance and resistance to atmospheric oxidation at elevated temperatures. The coatings are multilayered structures comprising solar absorbent layers (26) applied to the meta surface of the absorber tubes (50), typically stainless steel, topped with antireflective Savers (28) comprising at least two layers 30, 32) of refractory metal or metalloid oxides (such as titania and silica) with substantially differing indices of refraction in adjacent layers. Optionally, at least one layer of a noble metal such as platinum can be included between some of the layers. The absorbent layers cars include cermet materials comprising particles of metal compounds is a matrix, which can contain oxides of refractory metals or metalloids such as silicon. Reflective layers within the coating layers can comprise refractory metal silicides and related compounds characterized by the formulas TiSi. Ti.sub.3SiC.sub.2, TiAlSi, TiAN and similar compounds for Zr and Hf. The titania can be characterized by the formulas TiO.sub.2, Ti.sub.3O.sub.5. TiOx or TiO.sub.xN.sub.1-x with x 0 to 1. The silica can be at least one of SiO.sub.2, SiO.sub.2x or SiO.sub.2xN.sub.1-x with x=0 to 1.

  16. Structural characterization of high temperature composites

    NASA Technical Reports Server (NTRS)

    Mandell, J. F.; Grande, D. H.

    1991-01-01

    Glass, ceramic, and carbon matrix composite materials have emerged in recent years with potential properties and temperature resistance which make them attractive for high temperature applications such as gas turbine engines. At the outset of this study, only flexural tests were available to evaluate brittle matrix composites at temperatures in the 600 to 1000 C range. The results are described of an ongoing effort to develop appropriate tensile, compression, and shear test methods for high temperature use. A tensile test for unidirectional composites was developed and used to evaluate the properties and behavior of ceramic fiber reinforced glass and glass-ceramic matrix composites in air at temperatures up to 1000 C. The results indicate generally efficient fiber reinforcement and tolerance to matrix cracking similar to polymer matrix composites. Limiting properties in these materials may be an inherently very low transverse strain to failure, and high temperature embrittlement due to fiber/matrix interface oxidation.

  17. Development of the brine shrimp Artemia is accelerated during spaceflight

    NASA Technical Reports Server (NTRS)

    Spooner, B. S.; Metcalf, J.; DeBell, L.; Paulsen, A.; Noren, W.; Guikema, J. A.

    1994-01-01

    Developmentally arrested brine shrimp cysts have been reactivated during orbital spaceflight on two different Space Shuttle missions (STS-50 and STS-54), and their subsequent development has been compared with that of simultaneously reactivated ground controls. Flight and control brine shrimp do not significantly differ with respect to hatching rates or larval morphology at the scanning and transmission EM levels. A small percentage of the flight larvae had defective nauplier eye development, but the observation was not statistically significant. However, in three different experiments on two different flights, involving a total of 232 larvae that developed in space, a highly significant difference in degree of flight to control development was found. By as early as 2.25 days after reactivation of development, spaceflight brine shrimp were accelerated, by a full instar, over ground control brine shrimp. Although developing more rapidly, flight shrimp grew as long as control shrimp at each developmental instar or stage.

  18. Cloning and expression patterns of the brine shrimp (Artemia sinica) glycogen phosphorylase (GPase) gene during development and in response to temperature stress.

    PubMed

    Zhao, Na; Hou, Ming; Wang, Ting; Chen, Yifei; Lv, Ying; Li, Zengrong; Zhang, Rui; Xin, Wenting; Zou, Xiangyang; Hou, Lin

    2014-01-01

    Glycogen serves as a metabolic reserve and is involved in macromolecular synthesis. Glycogen phosphorylase (GPase) is a key enzyme involved in intracellular glycogen catabolism, catalyzing the first step in glycogen degradation. In the diapause, GPase catalyzes glycogen into the closely related molecule, sorbitol. In this study, the full-length cDNA of the GPase gene (2,790 bp) was isolated from Artemia sinica for the first time by rapid amplification of cDNA ends technology. The GPase gene encoded a protein of 853 amino acids belonging to the Glycosyltransferase GTB type superfamily. The expression pattern and location of GPase were investigated at various stages during the embryonic development of A. sinica using real-time PCR and in situ hybridization. High GPase expression was detected at the 0 and 5 h stages. Subsequently, expression declined and was maintained at a low level during the stages from 10 to 40 h following by a small increase at day 3. Expression was downregulated at temperatures ranging from 25 to 20 °C and was subsequently upregulated in the range 15-5 °C. In situ hybridization assays showed wide distribution of the GPase gene during different developmental stages. From the results of this study, we conclude that the GPase gene expression is stress-related and might play an important role in Artemia development and metabolism. PMID:24323193

  19. A batteryless temperature sensor based on high temperature sensitive material

    NASA Astrophysics Data System (ADS)

    Bakkali, Asma; Pelegri-Sebastia, José; Laghmich, Youssef; Lyhyaoui, Abdelouahid

    2016-05-01

    The major challenge in wireless sensor networks is the reduction of energy consumption. Passive wireless sensor network is an attractive solution for measuring physical parameters in harsh environment for large range of applications requiring sensing devices with low cost of fabrication, small size and long term measurement stability. Batteryless temperature sensing techniques are an active research field. The approach developed in our work holds a promising future for temperature sensor applications in order to successfully reduce the energy consumption. The temperature sensor presented in this paper is based on the electromagnetic transduction principle using the integration of the high temperature sensitive material into a passive structure. Variation in temperature makes the dielectric constant of this material changing, and such modification induces variation in the resonant frequencies of high-Q whispering-gallery modes (WGM) in the millimeter-wave frequency range. Following the results achieved, the proposed device shows a linear response to the increasing temperature and these variations can be remotely detected from a radar interrogation. Contribution to the topical issue "Materials for Energy Harvesting, Conversion and Storage (ICOME 2015) - Elected submissions", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

  20. Geothermal brine well: Mile-deep drill hole may tap ore-bearing magmatic water and rocks Undergoing Metamorphism

    USGS Publications Warehouse

    White, D.E.; Anderson, E.T.; Grubbs, D.K.

    1963-01-01

    A deep geothermal well in California has tapped a very saline brine extraordinarily high in heavy metals and other rare elements; copper and silver are precipitated during brine production. Preliminary evidence suggests that the brine may be pure magmatic water and an active ore-forming solution. Metamorphism of relatively young rocks may also be occurring within accessible depths.

  1. Geothermal Brine Well: Mile-Deep Drill Hole May Tap Ore-Bearing Magmatic Water and Rocks Undergoing Metamorphism.

    PubMed

    White, D E; Anderson, E T; Grubbs, D K

    1963-03-01

    A deep geothermal well in California has tapped a very saline brine extraordinarily high in heavy metals and other rare elements; copper and silver are precipitated during brine production. Preliminary evidence suggests that the brine may be pure magmatic water and an active ore-forming solution. Metamorphism of relatively young rocks may also be occurring within accessible depths.

  2. Gamma and alpha radiolysis of salt brines

    SciTech Connect

    Gray, W.J.; Simonson, S.A.

    1984-11-01

    Gamma radiolysis of Permian Basin brine leads to equilibrium gas pressure of about 100 atm. at 75/sup 0/C and about 40 atm. at 150/sup 0/C, providing the gas space is very small and/or the total dose is very high. Dose rate dependence is being investigated but is not yet established. Alpha radiolysis of Permian Bsin brine is still being pursued, but it is clear that equilibrium gas pressures will be much higher than with gamma radiolysis. Gas compositions in all cases have been about two parts H/sub 2/ to one part O/sub 2/. Efforts to simulate these results with computer models have been quite successful. 8 references, 6 figures, 1 table.

  3. High-temperature carbonates in the Stillwater Complex, Montana, USA

    NASA Astrophysics Data System (ADS)

    Aird, H. M.; Boudreau, A. E.

    2012-12-01

    The processes involved in the petrogenesis of the sulphide-hosted platinum-group-element (PGE) deposits of the Stillwater Complex are controversial, with theories ranging from the purely magmatic to those involving an aqueous fluid. To further constrain these models, we have been examining the trace phase assemblages in rocks away from the ore zones. High-temperature carbonates have been observed in association with sulphide minerals below the platiniferous J-M Reef of the Stillwater Complex. The carbonate assemblage consists of dolomite with exsolved calcite and is found in contact with sulphide minerals: chalcopyrite and pyrrhotite in the Peridotite Zone; and pyrrhotite with pentlandite, pyrite and chalcopyrite in Gabbronorite I of the Lower Banded Series. The minimal silicate alteration and the lack of greenschist minerals in association with the mineral assemblage are consistent with a high-temperature origin for the carbonates. The calcite-dolomite geothermometer [1] yields a minimum formation temperature of ~900°C for the unmixed assemblages. A reaction rim surrounds the carbonate-sulphide assemblages, showing an alteration of the host orthopyroxene to a more Ca-enriched, Fe-depleted composition. This is consistent with diffusive exchange between carbonates and pyroxenes at high temperatures, mediated by an aqueous fluid. The highly variable molar MnO/FeO ratios in both the high-temperature carbonates and their associated altered pyroxene rims also imply their interaction with a fluid. The carbonate assemblages are consistent with Stillwater fluid inclusion studies [2], showing that fluids comprising coexisting Cl-rich brine and carbonic fluid were trapped in pegmatitic quartz at 700-715°C, some of which also contained "accidental" calcite inclusions. The high Cl-content of apatite [3] found below the platiniferous J-M Reef is further evidence that a Cl-rich fluid was migrating through the rocks beneath the Reef. Carbonates have been shown to be stabilized

  4. Sandia_HighTemperatureComponentEvaluation_2015.

    SciTech Connect

    Cashion, Avery T.

    2015-03-01

    The objective of this project is to perform independent evaluation of high temperature components to determine their suitability for use in high temperature geothermal tools. Development of high temperature components has been increasing rapidly due to demand from the high temperature oil and gas exploration and aerospace industries. Many of these new components are at the late prototype or first production stage of development and could benefit from third party evaluation of functionality and lifetime at elevated temperatures. In addition to independent testing of new components, this project recognizes that there is a paucity of commercial-off-the-shelf COTS components rated for geothermal temperatures. As such, high-temperature circuit designers often must dedicate considerable time and resources to determine if a component exists that they may be able to knead performance out of to meet their requirements. This project aids tool developers by characterization of select COTS component performances beyond published temperature specifications. The process for selecting components includes public announcements of project intent (e.g., FedBizOps), direct discussions with candidate manufacturers,and coordination with other DOE funded programs.

  5. Low to high temperature energy conversion system

    NASA Technical Reports Server (NTRS)

    Miller, C. G. (Inventor)

    1977-01-01

    A method for converting heat energy from low temperature heat sources to higher temperature was developed. It consists of a decomposition chamber in which ammonia is decomposed into hydrogen and nitrogen by absorbing heat of decomposition from a low temperature energy source. A recombination reaction then takes place which increases the temperature of a fluid significantly. The system is of use for the efficient operation of compact or low capital investment turbine driven electrical generators, or in other applications, to enable chemical reactions that have a critical lower temperature to be used. The system also recovers heat energy from low temperature heat sources, such as solar collectors or geothermal sources, and converts it to high temperatures.

  6. Silicon Carbide Nanotube Oxidation at High Temperatures

    NASA Technical Reports Server (NTRS)

    Ahlborg, Nadia; Zhu, Dongming

    2012-01-01

    Silicon Carbide Nanotubes (SiCNTs) have high mechanical strength and also have many potential functional applications. In this study, SiCNTs were investigated for use in strengthening high temperature silicate and oxide materials for high performance ceramic nanocomposites and environmental barrier coating bond coats. The high · temperature oxidation behavior of the nanotubes was of particular interest. The SiCNTs were synthesized by a direct reactive conversion process of multiwall carbon nanotubes and silicon at high temperature. Thermogravimetric analysis (TGA) was used to study the oxidation kinetics of SiCNTs at temperatures ranging from 800degC to1300degC. The specific oxidation mechanisms were also investigated.

  7. Aeronautical applications of high-temperature superconductors

    NASA Technical Reports Server (NTRS)

    Turney, George E.; Luidens, Roger W.; Uherka, Kenneth; Hull, John

    1989-01-01

    The successful development of high-temperature superconductors (HTS) could have a major impact on future aeronautical propulsion and aeronautical flight vehicle systems. A preliminary examination of the potential application of HTS for aeronautics indicates that significant benefits may be realized through the development and implementation of these newly discovered materials. Applications of high-temperature superconductors (currently substantiated at 95 K) were envisioned for several classes of aeronautical systems, including subsonic and supersonic transports, hypersonic aircraft, V/STOL aircraft, rotorcraft, and solar, microwave and laser powered aircraft. Introduced and described are the particular applications and potential benefits of high-temperature superconductors as related to aeronautics and/or aeronautical systems.

  8. Symposium on high temperature and materials chemistry

    SciTech Connect

    Not Available

    1989-10-01

    This volume contains the written proceedings of the Symposium on High Temperature and Materials Chemistry held in Berkeley, California on October 24--25, 1989. The Symposium was sponsored by the Materials and Chemical Sciences Division of Lawrence Berkeley Laboratory and by the College of Chemistry of the University of California at Berkeley to discuss directions, trends, and accomplishments in the field of high temperature and materials chemistry. Its purpose was to provide a snapshot of high temperature and materials chemistry and, in so doing, to define status and directions.

  9. The high temperature superconductivity space experiment

    NASA Technical Reports Server (NTRS)

    Webb, Denis C.; Nisenoff, M.

    1991-01-01

    The history and the current status of the high temperature superconductivity space experiment (HTSSE) initiated in 1988 are briefly reviewed. The goal of the HTSSE program is to demonstrate the feasibility of incorporating high temperature superconductivity (HTS) technology into space systems. The anticipated payoffs include the development of high temperature superconductor devices for space systems; preparation and space qualification of a cryogenically cooled experimental package containing HTS devices and components; and acquisition of data for future space experiments using more complex HTS devices and subsystems. The principal HTSSE systems and devices are described.

  10. Dimensionality of high temperature superconductivity in oxides

    NASA Technical Reports Server (NTRS)

    Chu, C. W.

    1989-01-01

    Many models have been proposed to account for the high temperature superconductivity observed in oxide systems. Almost all of these models proposed are based on the uncoupled low dimensional carrier Cu-O layers of the oxides. Results of several experiments are presented and discussed. They suggest that the high temperature superconductivity observed cannot be strictly two- or one-dimensional, and that the environment between the Cu-O layers and the interlayer coupling play an important role in the occurrence of such high temperature superconductivity. A comment on the very short coherence length reported is also made.

  11. A high-temperature wideband pressure transducer

    NASA Technical Reports Server (NTRS)

    Zuckerwar, A. J.

    1975-01-01

    Progress in the development of a pressure transducer for measurement of the pressure fluctuations in the high temperature environment of a jet exhaust is reported. A condenser microphone carrier system was adapted to meet the specifications. A theoretical analysis is presented which describes the operation of the condenser microphone in terms of geometry, materials, and other physical properties. The analysis was used as the basis for design of a prototype high temperature microphone. The feasibility of connecting the microphone to a converter over a high temperature cable operating as a half-wavelength transmission line was also examined.

  12. High temperature solid state storage cell

    DOEpatents

    Rea, Jesse R.; Kallianidis, Milton; Kelsey, G. Stephen

    1983-01-01

    A completely solid state high temperature storage cell comprised of a solid rechargeable cathode such as TiS.sub.2, a solid electrolyte which remains solid at the high temperature operating conditions of the cell and which exhibits high ionic conductivity at such elevated temperatures such as an electrolyte comprised of lithium iodide, and a solid lithium or other alkali metal alloy anode (such as a lithium-silicon alloy) with 5-50% by weight of said anode being comprised of said solid electrolyte.

  13. High Temperature Thermographic Phosphor Coatings Development

    NASA Technical Reports Server (NTRS)

    Goedeke, Shawn; Allison, S. W.; Beshears, D. L.; Bencic, T.; Cates, M. R.; Hollerman, W. A.; Guidry, R.

    2003-01-01

    For many years, phosphor thermometry has been used for non-contact temperature measurements. A large number of applications have been associated with high temperatures, especially for aerospace systems where blackbody radiation backgrounds are large and in challenging environments, such as vibration, rotation, flame, or noise. These environments restrict the use of more common thermocouples or infrared thermometric techniques. In particular, temperature measurements inside jet turbines, rocket engines, or similar devices are especially amenable to phosphor techniques. Often the fluorescent materials are used as powders, either suspended in binders and applied like paint or applied as high-temperature sprays. Thin coatings that are less than 50 m thick are used on the surfaces of interest. These coatings will quickly assume the same temperature as the surface to which they are applied. The temperature dependence of fluorescent materials is a function of the base matrix atoms and a small quantity of added activator or dopant ions. Often for high temperature applications, the selected materials are refractory and include rare earth ions. Phosphors like Y3Al5O12 (YAG) doped with Eu, Dy, or Tm, Y2O3 doped with Eu, or similar rare earth compounds, will survive high temperatures and can be configured to emit light that changes rapidly in lifetime and intensity. For example, researchers at Oak Ridge National Laboratory recently observed fluorescence from YAG:Dy and YAG:Tm at temperatures above 1400 C. One of the biggest challenges is to locate a binder material that can withstand tremendous variations in temperature in an adverse aerospace environment. This poster will provide an overview into our attempt to utilize phosphors for thermometry purposes. Emphasis will be placed on the use of selected binder materials that can withstand high temperatures. This research was completed for the National Aeronautics and Space Administration's Glenn Research Center in Cleveland

  14. High temperature acclimation through PIF4 signaling.

    PubMed

    Proveniers, Marcel C G; van Zanten, Martijn

    2013-02-01

    Ambient temperature has direct consequences for plant functioning. Many plant species are able to adjust reproductive timing and development to optimize fitness to changes in ambient temperatures. Understanding the molecular networks of how plants cope with high temperatures is essential to counteract the effects of global warming and to secure future crop productivity. Several recent papers reported that Arabidopsis thaliana responses to changing light conditions and high temperature, and their underlying signaling mechanisms are highly similar and involve the basic helix-loop-helix (bHLH) transcription factor PHYTOCHROME INTERACTING FACTOR 4 (PIF4). In this opinion article we discuss the mechanisms of PIF4-mediated acclimation to increased ambient temperature with focus on timing of flowering and morphological acclimation.

  15. High temperature erosion of nickel alloys

    SciTech Connect

    Zhou, J.

    1995-12-31

    High temperature erosion behavior was studied on three commercial nickel alloys, Inconel 718, Inconel 601 and Inconel X-750, using a vertical sand-blast type of erosion test rig. Effect of temperature on erosion was investigated by varying test temperature in six steps from ambient up to 800 C. Other erosion variables investigated included impingement angle, changed from 10{degree} to 90{degree}, and impingement velocity, covered a range of 40 to 90 m/s. Extensive studies on erosion surface morphological features were done on eroded or eroded-corroded specimen surfaces using scanning electron microscopy. Thermogravimetric analysis and scratch test revealed corrosion rate, characteristics of oxide scale formed at high temperature, and some effects of corrosion on erosion. It was found that variation of erosion rate with temperature was directly related to temperature-dependent mechanical property changes of the materials. The mechanisms of the high-temperature erosion were analyzed based on test results. It was observed that erosion was dominant in temperature range up to 800 C, while corrosion played increased roles in upper portion of the temperature range tested.

  16. High temperature thermometric phosphors for use in a temperature sensor

    DOEpatents

    Allison, Stephen W.; Cates, Michael R.; Boatner, Lynn A.; Gillies, George T.

    1998-01-01

    A high temperature phosphor consists essentially of a material having the general formula LuPO.sub.4 :Dy.sub.(x),Eu.sub.(y), wherein: 0.1 wt %.ltoreq.x.ltoreq.20 wt % and 0.1 wt %.ltoreq.y.ltoreq.20 wt %. The high temperature phosphor is in contact with an article whose temperature is to be determined. The article having the phosphor in contact with it is placed in the environment for which the temperature of the article is to be determined. The phosphor is excited by a laser causing the phosphor to fluoresce. The emission from the phosphor is optically focused into a beam-splitting mirror which separates the emission into two separate emissions, the emission caused by the dysprosium dopant and the emission caused by the europium dopent. The separated emissions are optically filtered and the intensities of the emission are detected and measured. The ratio of the intensity of each emission is determined and the temperature of the article is calculated from the ratio of the intensities of the separate emissions.

  17. High temperature thermometric phosphors for use in a temperature sensor

    DOEpatents

    Allison, S.W.; Cates, M.R.; Boatner, L.A.; Gillies, G.T.

    1998-03-24

    A high temperature phosphor consists essentially of a material having the general formula LuPO{sub 4}:Dy{sub (x)},Eu{sub (y)}, wherein: 0.1 wt %{<=}x{<=}20 wt % and 0.1 wt %{<=}y{<=}20 wt %. The high temperature phosphor is in contact with an article whose temperature is to be determined. The article having the phosphor in contact with it is placed in the environment for which the temperature of the article is to be determined. The phosphor is excited by a laser causing the phosphor to fluoresce. The emission from the phosphor is optically focused into a beam-splitting mirror which separates the emission into two separate emissions, the emission caused by the dysprosium dopant and the emission caused by the europium dopant. The separated emissions are optically filtered and the intensities of the emission are detected and measured. The ratio of the intensity of each emission is determined and the temperature of the article is calculated from the ratio of the intensities of the separate emissions. 2 figs.

  18. Dense, Viscous Brine Behavior in Heterogeneous Porous Medium Systems

    PubMed Central

    Wright, D. Johnson; Pedit, J.A.; Gasda, S.E.; Farthing, M.W.; Murphy, L.L.; Knight, S.R.; Brubaker, G.R.

    2010-01-01

    The behavior of dense, viscous calcium bromide brine solutions used to remediate systems contaminated with dense nonaqueous phase liquids (DNAPLs) is considered in laboratory and field porous medium systems. The density and viscosity of brine solutions are experimentally investigated and functional forms fit over a wide range of mass fractions. A density of 1.7 times, and a corresponding viscosity of 6.3 times, that of water is obtained at a calcium bromide mass fraction of 0.53. A three-dimensional laboratory cell is used to investigate the establishment, persistence, and rate of removal of a stratified dense brine layer in a controlled system. Results from a field-scale experiment performed at the Dover National Test Site are used to investigate the ability to establish and maintain a dense brine layer as a component of a DNAPL recovery strategy, and to recover the brine at sufficiently high mass fractions to support the economical reuse of the brine. The results of both laboratory and field experiments show that a dense brine layer can be established, maintained, and recovered to a significant extent. Regions of unstable density profiles are shown to develop and persist in the field-scale experiment, which we attribute to regions of low hydraulic conductivity. The saturated-unsaturated, variable-density ground-water flow simulation code SUTRA is modified to describe the system of interest, and used to compare simulations to experimental observations and to investigate certain unobserved aspects of these complex systems. The model results show that the standard model formulation is not appropriate for capturing the behavior of sharp density gradients observed during the dense brine experiments. PMID:20444520

  19. Dense, viscous brine behavior in heterogeneous porous medium systems.

    PubMed

    Wright, D Johnson; Pedit, J A; Gasda, S E; Farthing, M W; Murphy, L L; Knight, S R; Brubaker, G R; Miller, C T

    2010-06-25

    The behavior of dense, viscous calcium bromide brine solutions used to remediate systems contaminated with dense nonaqueous phase liquids (DNAPLs) is considered in laboratory and field porous medium systems. The density and viscosity of brine solutions are experimentally investigated and functional forms fit over a wide range of mass fractions. A density of 1.7 times, and a corresponding viscosity of 6.3 times, that of water is obtained at a calcium bromide mass fraction of 0.53. A three-dimensional laboratory cell is used to investigate the establishment, persistence, and rate of removal of a stratified dense brine layer in a controlled system. Results from a field-scale experiment performed at the Dover National Test Site are used to investigate the ability to establish and maintain a dense brine layer as a component of a DNAPL recovery strategy, and to recover the brine at sufficiently high mass fractions to support the economical reuse of the brine. The results of both laboratory and field experiments show that a dense brine layer can be established, maintained, and recovered to a significant extent. Regions of unstable density profiles are shown to develop and persist in the field-scale experiment, which we attribute to regions of low hydraulic conductivity. The saturated-unsaturated, variable-density groundwater flow simulation code SUTRA is modified to describe the system of interest, and used to compare simulations to experimental observations and to investigate certain unobserved aspects of these complex systems. The model results show that the standard model formulation is not appropriate for capturing the behavior of sharp density gradients observed during the dense brine experiments.

  20. Electrical Properties Of Capacitors At High Temperatures

    NASA Technical Reports Server (NTRS)

    Baumann, E. D.; Myers, I. T.; Overton, E.; Hammoud, A. N.

    1994-01-01

    Brief report describes results of experiments in which capacitance and dielectric loss of glass, metallized-polytetrafluoroethylene, and solid-tantalum capacitor measured at temperatures from 20 degrees C to 200 degrees C. Conclusions drawn concerning suitability of capacitors for use at high temperatures; such as in nuclear powerplants, aircraft, equipment for extracting geothermal energy, switching power supplies, and automotive integrated engine electronics.

  1. High temperature ceramic/metal joint structure

    DOEpatents

    Boyd, Gary L.

    1991-01-01

    A high temperature turbine engine includes a hybrid ceramic/metallic rotor member having ceramic/metal joint structure. The disclosed joint is able to endure higher temperatures than previously possible, and aids in controlling heat transfer in the rotor member.

  2. High temperature superconductor materials and applications

    NASA Technical Reports Server (NTRS)

    Doane, George B., III.; Banks, Curtis; Golben, John

    1990-01-01

    Research on processing methods leading to a significant enhancement in the critical current densities (Jc) and the critical temperature (Tc) of high temperature superconducting in thin bulk and thin film forms. The fabrication of important devices for NASA unique applications (sensors) is investigated.

  3. Brine Pockets in the Icy Shell on Europa: Distribution, Chemistry, and Habitability

    NASA Technical Reports Server (NTRS)

    Zolotov, M. Yu; Shock, E. L.; Barr, A. C.; Pappalardo, R. T.

    2004-01-01

    On Earth, sea ice is rich in brine, salt, and gas inclusions that form through capturing of seawater during ice formation. Cooling of the ice over time leads to sequential freezing of captured sea-water, precipitation of salts, exsolution of gases, and formation of brine channels and pockets. Distribution and composition of brines in sea ice depend on the rate of ice formation, vertical temperature gradient, and the age of the ice. With aging, the abundance of brine pockets decreases through downward migration. De- spite low temperatures and elevated salinities, brines in sea ice provide a habitat for photosynthetic and chemosynthetic organisms. On Europa, brine pockets and channels could exist in the icy shell that may be from a few km to a few tens of km thick and is probably underlain by a water ocean. If the icy shell is relatively thick, convection could develop, affecting the temperature pattern in the ice. To predict the distribution and chemistry of brine pockets in the icy shell we have combined numerical models of the temperature distribution within a convecting shell, a model for oceanic chemistry, and a model for freezing of Europan oceanic water. Possible effects of brine and gas inclusions on ice rheology and tectonics are discussed.

  4. Characterization of brines and evaporites of Lake Katwe, Uganda

    NASA Astrophysics Data System (ADS)

    Kasedde, Hillary; Kirabira, John Baptist; Bäbler, Matthäus U.; Tilliander, Anders; Jonsson, Stefan

    2014-03-01

    Lake Katwe brines and evaporites were investigated to determine their chemical, mineralogical and morphological composition. 30 brine samples and 3 solid salt samples (evaporites) were collected from different locations of the lake deposit. Several analytical techniques were used to determine the chemical composition of the samples including Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES), Inductively Coupled Plasma-Sector Field Mass Spectrometry (ICP-SFMS), ion chromatography, and potentiometric titration. The mineralogical composition and morphology of the evaporites was determined using X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Physical parameters of the lake brines such as density, electrical conductivity, pH, and salinity were also studied. The results show that the lake brines are highly alkaline and rich in Na+, Cl-, CO32-, SO42-, and HCO3- with lesser amounts of K+, Mg2+, Ca2+, Br-, and F- ions. The brines show an intermediate transition between Na-Cl and Na-HCO3 water types. Among the trace metals, the lake brines were found to be enriched in B, I, Sr, Fe, Mo, Ba, and Mn. The solid salts are composed of halite mixed with other salts such as hanksite, burkeite and trona. It was also observed that the composition of the salts varies considerably even within the same grades.

  5. Assigning thermodynamic temperatures to high-temperature fixed-points

    NASA Astrophysics Data System (ADS)

    Woolliams, E. R.; Bloembergen, P.; Machin, G.

    2013-09-01

    Workpackage five of the High Temperature Fixed-Point research programme will determine the thermodynamic temperature for the equilibrium melting transition of the pure eutectic systems of Re-C, Pt-C and Co-C and, in addition, the freezing point of Cu. Measurements of four different cells of each type will be made by nine participating laboratories. This paper describes how the melt sensitivity to the rate of the previous freeze, furnace effects and cell impurities will be accounted for and how the results will be combined allowing for all existing correlations.

  6. High-Temperature Optical Window Design

    NASA Technical Reports Server (NTRS)

    Roeloffs, Norman; Taranto, Nick

    1995-01-01

    A high-temperature optical window is essential to the optical diagnostics of high-temperature combustion rigs. Laser Doppler velocimetry, schlieren photography, light sheet visualization, and laser-induced fluorescence spectroscopy are a few of the tests that require optically clear access to the combustor flow stream. A design was developed for a high-temperature window that could withstand the severe environment of the NASA Lewis 3200 F Lean Premixed Prevaporized (LPP) Flame Tube Test Rig. The development of this design was both time consuming and costly. This report documents the design process and the lessons learned, in an effort to reduce the cost of developing future designs for high-temperature optical windows.

  7. A sharp knife for high temperatures

    NASA Technical Reports Server (NTRS)

    Heisman, R. M.; Iceland, W. F.

    1978-01-01

    Electrically heated nickel-chrome-steel alloy knife may be used to cut heat resistant plastic felt and similar materials with relative ease. Blade made of commercially available alloy RA 330 retains edge at temperatures as high as 927 C.

  8. Measuring Moduli Of Elasticity At High Temperatures

    NASA Technical Reports Server (NTRS)

    Wolfenden, Alan

    1993-01-01

    Shorter, squatter specimens and higher frequencies used in ultrasonic measurement technique. Improved version of piezo-electric ultrasonic composite oscillator technique used to measure moduli of elasticity of solid materials at high temperatures.

  9. Silicon carbide, an emerging high temperature semiconductor

    NASA Technical Reports Server (NTRS)

    Matus, Lawrence G.; Powell, J. Anthony

    1991-01-01

    In recent years, the aerospace propulsion and space power communities have expressed a growing need for electronic devices that are capable of sustained high temperature operation. Applications for high temperature electronic devices include development instrumentation within engines, engine control, and condition monitoring systems, and power conditioning and control systems for space platforms and satellites. Other earth-based applications include deep-well drilling instrumentation, nuclear reactor instrumentation and control, and automotive sensors. To meet the needs of these applications, the High Temperature Electronics Program at the Lewis Research Center is developing silicon carbide (SiC) as a high temperature semiconductor material. Research is focussed on developing the crystal growth, characterization, and device fabrication technologies necessary to produce a family of silicon carbide electronic devices and integrated sensors. The progress made in developing silicon carbide is presented, and the challenges that lie ahead are discussed.

  10. High-temperature superconductivity: A conventional conundrum

    DOE PAGESBeta

    Božović, Ivan

    2016-01-07

    High-temperature superconductivity in ultrathin films of iron selenide deposited on strontium titanate has been attributed to various exotic mechanisms, and new experiments indicate that it may be conventional, with broader implications.

  11. The Conference on High Temperature Electronics

    NASA Technical Reports Server (NTRS)

    Hamilton, D. J.; Mccormick, J. B.; Kerwin, W. J.; Narud, J. A.

    1981-01-01

    The status of and directions for high temperature electronics research and development were evaluated. Major objectives were to (1) identify common user needs; (2) put into perspective the directions for future work; and (3) address the problem of bringing to practical fruition the results of these efforts. More than half of the presentations dealt with materials and devices, rather than circuits and systems. Conference session titles and an example of a paper presented in each session are (1) User requirements: High temperature electronics applications in space explorations; (2) Devices: Passive components for high temperature operation; (3) Circuits and systems: Process characteristics and design methods for a 300 degree QUAD or AMP; and (4) Packaging: Presently available energy supply for high temperature environment.

  12. Altering high temperature subterranean formation permeability

    SciTech Connect

    Moradi-Araghi, A.

    1991-02-19

    This patent describes a delayed acrylamide containing polymer crosslinker having stability in an aqueous solution at high temperatures. It comprises: a combination of an aldehyde and a salicylic acid derivative selected from salicylamide and acetysalicylic acid.

  13. Microbial changes and growth of Listeria monocytogenes during chilled storage of brined shrimp (Pandalus borealis).

    PubMed

    Mejlholm, Ole; Kjeldgaard, Jette; Modberg, Anne; Vest, Mette Bohn; Bøknaes, Niels; Koort, Joanna; Björkroth, Johanna; Dalgaard, Paw

    2008-06-10

    Thirteen storage trials and ten challenge tests were carried out to examine microbial changes, spoilage and the potential growth of Listeria monocytogenes in brined shrimp (Pandalus borealis). Shrimp in brine as well as brined and drained shrimp in modified atmosphere packaging (MAP) were produced and studied. Different recipes were used to study the effect of preserving parameters (organic acids, pH and NaCl) on growth of microorganisms and shelf life at 7-8 degrees C or 12 degrees C. Particularly, brines with different concentrations of (i) benzoic, citric and sorbic acids or (ii) acetic, citric and lactic acids were studied. Furthermore, the effect of adding diacetate to brined shrimp was evaluated. A single batch of cooked and peeled shrimp was used to study both industrially and manually processed brined shrimp with respect to the effect of process hygiene on microbial changes and the shelf life of products. Concentrations of microorganisms on newly produced brined shrimp from an industrial scale processing line were 1.0-2.3 log (CFU g(-1)) higher than comparable concentrations in manually processed samples. This resulted in a substantially shorter shelf life and a more diverse spoilage microflora of the industrially processed brined shrimp. In addition, shelf life of brined shrimp was affected by the types and concentrations of organic acids and by the storage temperature as expected. The effect of MAP was less pronounced. Eighty-two isolates from the spoilage microflora of brined shrimp were identified and they included 53 lactic acid bacteria, 6 coagulase negative Staphylococcus spp., 18 Pseudomonas fluorescens and 5 yeast isolates. After storage at 7 degrees C, P. fluorescens, Enterococcus-like isolates, E. malodoratus, Carnobacterium maltaromaticum, coagulase negative Staphylococcus spp. and Lactobacillus sakei constituted the dominating microflora of shrimp in brines that contained benzoic, citric and sorbic acids as preservatives. L. sakei dominated the

  14. Materials for high-temperature thermoelectric conversion

    NASA Technical Reports Server (NTRS)

    Feigelson, R. S.; Elwell, D.; Auld, B. A.

    1984-01-01

    The development of materials for high temperature thermoelectric energy conversion devices was investigated. The development of new criteria for the selection of materials which is based on understanding of the fundamental principles governing the behavior of high temperature thermoelectric materials is discussed. The synthesis and characterization of promising new materials and the growth of single crystals to eliminate possible problems associated with grain boundaries and other defects in polycrystalline materials are outlined.

  15. PLA recycling by hydrolysis at high temperature

    NASA Astrophysics Data System (ADS)

    Cristina, Annesini Maria; Rosaria, Augelletti; Sara, Frattari; Fausto, Gironi

    2016-05-01

    In this work the process of PLA hydrolysis at high temperature was studied, in order to evaluate the possibility of chemical recycling of this polymer bio-based. In particular, the possibility to obtain the monomer of lactic acid from PLA degradation was investigated. The results of some preliminary tests, performed in a laboratory batch reactor at high temperature, are presented: the experimental results show that the complete degradation of PLA can be obtained in relatively low reaction times.

  16. Recent developments in high temperature organic polymers

    NASA Technical Reports Server (NTRS)

    Hergenrother, P. M.

    1991-01-01

    Developments in high temperature organic polymers during the last 5 years with major emphasis on polyimides and poly(arylene ether)s are discussed. Specific polymers or series of polymers have been selected to demonstrate unique properties or the effect chemical structure has upon certain properties. This article is not intended to be a comprehensive review of high temperature polymer advancements during the last 5 years.

  17. High temperature structural fibers: Status and needs

    NASA Technical Reports Server (NTRS)

    Dicarlo, James A.

    1991-01-01

    The key to high temperature structural composites is the selection and incorporation of continuous fiber reinforcement with optimum mechanical, physical, and chemical properties. Critical fiber property needs are high strength, high stiffness, and retention of these properties during composite fabrication and use. However, unlike polymeric composites where all three requirements are easily achieved with a variety of commercially available carbon-based fibers, structural fibers with sufficient stiffness and strength retention for high temperature metal, intermetallic, and ceramic composites are not available. The objective here is to discuss in a general manner the thermomechanical stability problem for current high performance fibers which are based on silicon and alumina compositions. This is accomplished by presenting relevant fiber property data with a brief discussion of potential underlying mechanisms. From this general overview, some possible materials engineering approaches are suggested which may lead to minimization and/or elimination of this critical stability problem for current high temperature fibers.

  18. Apparatus and method for high temperature viscosity and temperature measurements

    DOEpatents

    Balasubramaniam, Krishnan; Shah, Vimal; Costley, R. Daniel; Singh, Jagdish P.

    2001-01-01

    A probe for measuring the viscosity and/or temperature of high temperature liquids, such as molten metals, glass and similar materials comprises a rod which is an acoustical waveguide through which a transducer emits an ultrasonic signal through one end of the probe, and which is reflected from (a) a notch or slit or an interface between two materials of the probe and (b) from the other end of the probe which is in contact with the hot liquid or hot melt, and is detected by the same transducer at the signal emission end. To avoid the harmful effects of introducing a thermally conductive heat sink into the melt, the probe is made of relatively thermally insulative (non-heat-conductive) refractory material. The time between signal emission and reflection, and the amplitude of reflections, are compared against calibration curves to obtain temperature and viscosity values.

  19. Quasipermanent magnets of high temperature superconductor - Temperature dependence

    NASA Technical Reports Server (NTRS)

    Chen, In-Gann; Liu, Jianxiong; Ren, Yanru; Weinstein, Roy; Kozlowski, Gregory; Oberly, Charles E.

    1993-01-01

    We report on persistent field in quasi-permanent magnets of high temperature superconductors. Magnets composed of irradiated Y(1+)Ba2Cu3O7 trapped field Bt = 1.52 T at 77 K and 1.9 T at lower temperature. However, the activation magnet limited Bt at lower temperature. We present data on Jc(H,T) for unirradiated materials, and calculate Bt at various T. Based upon data at 65 K, we calculate Bt in unirradiated single grains at 20 K and find that 5.2 T will be trapped for grain diameter d about 1.2 cm, and 7.9 T for d = 2.3 cm. Irradiated grains will trap four times these values.

  20. Photocatalytic reduction of nitrate using titanium dioxide for regeneration of ion exchange brine.

    PubMed

    Yang, Ting; Doudrick, Kyle; Westerhoff, Paul

    2013-03-01

    Nitrate is often removed from groundwater by ion exchange (IX) before its use as drinking water. Accumulation of nitrate in IX brine reduces the efficiency of IX regeneration and the useful life of the regeneration brine. For the first time, we present a strategy to photocatalytically reduce nitrate in IX brine, thereby extending the use of the brine. Titanium dioxide (Evonik P90), acting as photocatalyst, reduced nitrate effectively in both synthetic brines and sulfate-removed IX brine when formic acid (FA) was used as the hole scavenger (i.e., electron donor) and the initial FA to nitrate molar ratio (IFNR) was 5.6. Increasing the NaCl level in the synthetic brine slowed the nitrate reduction rate without affecting by-product selectivity of ammonium and gaseous N species (e.g., N(2), N(2)O). In a non-modified IX brine, nitrate removal was greatly inhibited owing to the presence of sulfate, which competed with nitrate for active surface sites on P90 and induced aggregation of P90 nanoparticles. After removing sulfate through barium sulfate precipitation, nitrate was effectively reduced; approximately 3.6 × 10(24) photons were required to reduce each mole of nitrate to 83% N Gases and 17% NH(4)(+). To make optimum use of FA and control the residual FA level in treated brine, the IFNR was varied. High IFNRs (e.g., 4, 5.6) were found to be more efficient for nitrate reduction but left higher residual FA in brine. IX column tests were performed to investigate the impact of residual FA for brine reuse. The residual FA in the brine did not significantly affect the nitrate removal capacity of IX resins, and formate contamination of treated water could be eliminated by rinsing with one bed volume of fresh brine.

  1. Photocatalytic reduction of nitrate using titanium dioxide for regeneration of ion exchange brine

    PubMed Central

    Yang, Ting; Doudrick, Kyle; Westerhoff, Paul

    2016-01-01

    Nitrate is often removed from groundwater by ion exchange (IX) before its use as drinking water. Accumulation of nitrate in IX brine reduces the efficiency of IX regeneration and the useful life of the regeneration brine. For the first time, we present a strategy to photocatalytically reduce nitrate in IX brine, thereby extending the use of the brine. Titanium dioxide (Evonik P90), acting as photocatalyst, reduced nitrate effectively in both synthetic brines and sulfate-removed IX brine when formic acid (FA) was used as the hole scavenger (i.e., electron donor) and the initial FA to nitrate molar ratio (IFNR) was 5.6. Increasing the NaCl level in the synthetic brine slowed the nitrate reduction rate without affecting byproduct selectivity of ammonium and gaseous N species (e.g., N2, N2O). In a non-modified IX brine, nitrate removal was greatly inhibited owing to the presence of sulfate, which competed with nitrate for active surface sites on P90 and induced aggregation of P90 nanoparticles. After removing sulfate through barium sulfate precipitation, nitrate was effectively reduced; approximately 3.6 × 1024 photons were required to reduce each mole of nitrate to 83% N Gases and 17% NH4+. To make optimum use of FA and control the residual FA level in treated brine, the IFNR was varied. High IFNRs (e.g., 4, 5.6) were found to be more efficient for nitrate reduction but left higher residual FA in brine. IX column tests were performed to investigate the impact of residual FA for brine reuse. The residual FA in the brine did not significantly affect the nitrate removal capacity of IX resins, and formate contamination of treated water could be eliminated by rinsing with one bed volume of fresh brine. PMID:23276425

  2. Gas evolution from geopressured brines

    SciTech Connect

    Matthews, C.S.

    1980-06-01

    The process of gas evolution from geopressured brine is examined using as a basis the many past studies of gas evolution from liquids in porous media. A discussion of a number of speculations that have been made concerning gas evolution from geopressured brines is provided. According to one, rapid pressure reduction will cause methane gas to evolve as when one opens a champagne bottle. It has been further speculated that evolved methane gas would migrate up to form an easily producible cap. As a result of detailed analyses, it can be concluded that methane gas evolution from geopressured brines is far too small to ever form a connected gas saturation except very near to the producing well. Thus, no significant gas cap could ever form. Because of the very low solubility of methaned in brine, the process of methane gas evolution is not at all analogous to evolution of carbon dioxide from champagne. A number of other speculations and questions on gas evolution are analyzed, and procedures for completing wells and testing geopressured brine reservoirs are discussed, with the conclusion that presently used procedures will provide adequate data to enable a good evaluation of this resource.

  3. Ionization of NO at high temperature

    NASA Technical Reports Server (NTRS)

    Hansen, C. Frederick

    1991-01-01

    Space vehicles flying through the atmosphere at high speed are known to excite a complex set of chemical reactions in the atmospheric gases, ranging from simple vibrational excitation to dissociation, atom exchange, electronic excitation, ionization, and charge exchange. Simple arguments are developed for the temperature dependence of the reactions leading to ionization of NO, including the effect of vibrational electronic thermal nonequilibrium. NO ionization is the most important source of electrons at intermediate temperatures and at higher temperatures provides the trigger electrons that ionize atoms. Based on these arguments, recommendations are made for formulae which fit observed experimental results, and which include a dependence on both a heavy particle temperature and different vibration electron temperatures. In addition, these expressions will presumably provide the most reliable extrapolation of experimental results to much higher temperatures.

  4. Water and Brines on Mars: Current Evidence and Implications for MSL

    NASA Astrophysics Data System (ADS)

    Martínez, G. M.; Renno, N. O.

    2013-06-01

    Liquid water is a basic ingredient for life as we know it. Therefore, in order to understand the habitability of other planets we must first understand the behavior of water on them. Mars is the most Earth-like planet in the solar system and it has large reservoirs of H2O. Here, we review the current evidence for pure liquid water and brines on Mars, and discuss their implications for future and current missions such as the Mars Science Laboratory. Neither liquid water nor liquid brines are currently stable on the surface of Mars, but they could be present temporarily in a few areas of the planet. Pure liquid water is unlikely to be present, even temporarily, on the surface of Mars because evaporation into the extremely dry atmosphere would inhibit the formation of the liquid phase, where the temperature and pressure are high enough so that water would neither freeze nor boil. The exception to this is that monolayers of liquid water, referred to as undercooled liquid interfacial water, could exist on most of the Martian surface. In a few places liquid brines could exist temporarily on the surface because they could form at cryogenic temperatures, near ice or frost deposits where sublimation could be inhibited by the presence of nearly saturated air. Both liquid water and liquid brines might exist in the shallow subsurface because even a thin layer of soil forms an effective barrier against sublimation allowing pure liquid water to form sporadically in a few places, or liquid brines to form over longer periods of time in large portions of the planet. At greater depths, ice deposits could melt where the soil conductivity is low enough to blanket the deeper subsurface effectively. This could cause the formation of aquifers if the deeper soil is sufficiently permeable and an impermeable layer exists below the source of water. The fact that liquid brines and groundwater are likely to exist on Mars has important implications for geochemistry, glaciology, mineralogy

  5. Electrically Conducting, Ca-Rich Brines, Rather Than Water, Expected in the Martian Subsurface

    NASA Technical Reports Server (NTRS)

    Burt, D. M.; Knauth, L. P.

    2003-01-01

    If Mars ever possessed a salty liquid hydrosphere, which later partly evaporated and froze down, then any aqueous fluids left near the surface could have evolved to become dense eutectic brines. Eutectic brines, by definition, are the last to freeze and the first to melt. If CaC12-rich, such brines can remain liquid until temperatures below 220 K, close to the average surface temperature of Mars. In the Martian subsurface, in intimate contact with the Ca-rich basaltic regolith, NaC1-rich early brines should have reacted to become Ca-rich. Fractional crystallization (freezing) and partial melting would also drive brines toward CaC12-rich compositions. In other words, eutectic brine compositions could be present in the shallow subsurface of Mars, for the same reasons that eutectic magma compositions are common on Earth. Don Juan Pond, Antarctica, a CaC12-rich eutectic brine, provides a possible terrestrial analog, particularly because it is fed from a basaltic aquifer. Owing to their relative density and fluid nature, brines in the Martian regolith should eventually become sandwiched between ice above and salts beneath. A thawing brine sandwich provides one explanation (among many) for the young gullies recently attributed to seepage of liquid water on Mars. Whether or not brine seepage explains the gullies phenomenon, dense, CaC12-rich brines are to be expected in the deep subsurface of Mars, although they might be somewhat diluted (temperatures permitting) and of variable salt composition. In any case, they should be good conductors of electricity.

  6. Oxygen Ion--Conducting Ceramics: A New Application in High-Temperature--High-Pressure pH Sensors.

    PubMed

    Niedrach, L W

    1980-03-14

    Membrane electrodes fabricated from yttria-stabilized zirconia, a representative oxygen ion-conducting ceramic, show a linear voltage response to pH over the range 3 to 8 at 285 degrees C and a pressure of 1200 pounds per square inch (82 atmospheres). Test units have been operated continuously at 285 degrees C without failure for periods as long as 9 days. Unlike sensors which are based on electron transfer couples, such membrane electrodes are insensitive to changes in the oxidation-reduction environment and, in turn, exert no influence upon the environment. Such ceramic membranes can therefore be used for the direct measurement of the pH of geothermal brines, of water in nuclear reactors, and in high-temperature thermodynamic studies on aqueous systems.

  7. High temperature crystalline superconductors from crystallized glasses

    DOEpatents

    Shi, Donglu

    1992-01-01

    A method of preparing a high temperature superconductor from an amorphous phase. The method involves preparing a starting material of a composition of Bi.sub.2 Sr.sub.2 Ca.sub.3 Cu.sub.4 Ox or Bi.sub.2 Sr.sub.2 Ca.sub.4 Cu.sub.5 Ox, forming an amorphous phase of the composition and heat treating the amorphous phase for particular time and temperature ranges to achieve a single phase high temperature superconductor.

  8. A halophilic bacterium inhabiting the warm, CaCl2-rich brine of the perennially ice-covered Lake Vanda, McMurdo Dry Valleys, Antarctica.

    PubMed

    Tregoning, George S; Kempher, Megan L; Jung, Deborah O; Samarkin, Vladimir A; Joye, Samantha B; Madigan, Michael T

    2015-03-01

    Lake Vanda is a perennially ice-covered and stratified lake in the McMurdo Dry Valleys, Antarctica. The lake develops a distinct chemocline at about a 50-m depth, where the waters transition from cool, oxic, and fresh to warm, sulfidic, and hypersaline. The bottom water brine is unique, as the highly chaotropic salts CaCl2 and MgCl2 predominate, and CaCl2 levels are the highest of those in any known microbial habitat. Enrichment techniques were used to isolate 15 strains of heterotrophic bacteria from the Lake Vanda brine. Despite direct supplementation of the brine samples with different organic substrates in primary enrichments, the same organism, a relative of the halophilic bacterium Halomonas (Gammaproteobacteria), was isolated from all depths sampled. The Lake Vanda (VAN) strains were obligate aerobes and showed broad pH, salinity, and temperature ranges for growth, consistent with the physicochemical properties of the brine. VAN strains were halophilic and quite CaCl2 tolerant but did not require CaCl2 for growth. The fact that only VAN strain-like organisms appeared in our enrichments hints that the highly chaotropic nature of the Lake Vanda brine may place unusual physiological constraints on the bacterial community that inhabits it. PMID:25576606

  9. A Halophilic Bacterium Inhabiting the Warm, CaCl2-Rich Brine of the Perennially Ice-Covered Lake Vanda, McMurdo Dry Valleys, Antarctica

    PubMed Central

    Tregoning, George S.; Kempher, Megan L.; Jung, Deborah O.; Samarkin, Vladimir A.; Joye, Samantha B.

    2015-01-01

    Lake Vanda is a perennially ice-covered and stratified lake in the McMurdo Dry Valleys, Antarctica. The lake develops a distinct chemocline at about a 50-m depth, where the waters transition from cool, oxic, and fresh to warm, sulfidic, and hypersaline. The bottom water brine is unique, as the highly chaotropic salts CaCl2 and MgCl2 predominate, and CaCl2 levels are the highest of those in any known microbial habitat. Enrichment techniques were used to isolate 15 strains of heterotrophic bacteria from the Lake Vanda brine. Despite direct supplementation of the brine samples with different organic substrates in primary enrichments, the same organism, a relative of the halophilic bacterium Halomonas (Gammaproteobacteria), was isolated from all depths sampled. The Lake Vanda (VAN) strains were obligate aerobes and showed broad pH, salinity, and temperature ranges for growth, consistent with the physicochemical properties of the brine. VAN strains were halophilic and quite CaCl2 tolerant but did not require CaCl2 for growth. The fact that only VAN strain-like organisms appeared in our enrichments hints that the highly chaotropic nature of the Lake Vanda brine may place unusual physiological constraints on the bacterial community that inhabits it. PMID:25576606

  10. High Temperature, Wireless Seismometer Sensor for Venus

    NASA Technical Reports Server (NTRS)

    Ponchak, George E.; Scardelletti, Maximilian C.; Taylor, Brandt; Beard, Steve; Meredith, Roger D.; Beheim, Glenn M.; Hunter Gary W.; Kiefer, Walter S.

    2012-01-01

    Space agency mission plans state the need to measure the seismic activity on Venus. Because of the high temperature on Venus (462? C average surface temperature) and the difficulty in placing and wiring multiple sensors using robots, a high temperature, wireless sensor using a wide bandgap semiconductor is an attractive option. This paper presents the description and proof of concept measurements of a high temperature, wireless seismometer sensor for Venus. A variation in inductance of a coil caused by the movement of an aluminum probe held in the coil and attached to a balanced leaf-spring seismometer causes a variation of 700 Hz in the transmitted signal from the oscillator/sensor system at 426? C. This result indicates that the concept may be used on Venus.

  11. High-entropy alloys as high-temperature thermoelectric materials

    SciTech Connect

    Shafeie, Samrand; Guo, Sheng; Hu, Qiang; Fahlquist, Henrik; Erhart, Paul; Palmqvist, Anders

    2015-11-14

    Thermoelectric (TE) generators that efficiently recycle a large portion of waste heat will be an important complementary energy technology in the future. While many efficient TE materials exist in the lower temperature region, few are efficient at high temperatures. Here, we present the high temperature properties of high-entropy alloys (HEAs), as a potential new class of high temperature TE materials. We show that their TE properties can be controlled significantly by changing the valence electron concentration (VEC) of the system with appropriate substitutional elements. Both the electrical and thermal transport properties in this system were found to decrease with a lower VEC number. Overall, the large microstructural complexity and lower average VEC in these types of alloys can potentially be used to lower both the total and the lattice thermal conductivity. These findings highlight the possibility to exploit HEAs as a new class of future high temperature TE materials.

  12. High-entropy alloys as high-temperature thermoelectric materials

    NASA Astrophysics Data System (ADS)

    Shafeie, Samrand; Guo, Sheng; Hu, Qiang; Fahlquist, Henrik; Erhart, Paul; Palmqvist, Anders

    2015-11-01

    Thermoelectric (TE) generators that efficiently recycle a large portion of waste heat will be an important complementary energy technology in the future. While many efficient TE materials exist in the lower temperature region, few are efficient at high temperatures. Here, we present the high temperature properties of high-entropy alloys (HEAs), as a potential new class of high temperature TE materials. We show that their TE properties can be controlled significantly by changing the valence electron concentration (VEC) of the system with appropriate substitutional elements. Both the electrical and thermal transport properties in this system were found to decrease with a lower VEC number. Overall, the large microstructural complexity and lower average VEC in these types of alloys can potentially be used to lower both the total and the lattice thermal conductivity. These findings highlight the possibility to exploit HEAs as a new class of future high temperature TE materials.

  13. Fast vortex core switching at high temperatures

    NASA Astrophysics Data System (ADS)

    Lebecki, Kristof M.; Legut, Dominik

    2016-08-01

    Fast ferromagnetic vortex core switching is investigated employing micromagnetic simulations. Short pulse (in the range of a few hundreds of picoseconds) of an in-plane oscillating magnetic field is applied to a thin disk (diameter 200 nm and thickness 20 nm) with material parameters resembling permalloy. Fundamental frequency of this excitation field is close to the resonance with the material spin waves. Thermal effects are introduced by replacing the Landau-Lifshitz-Gilbert equation by the Landau-Lifshitz-Bloch equation. Temperature from 300 K to 850 K is considered, just below the Curie temperature TC = 870 K. Calculations are done within the OOMMF simulation framework. We find that: (i) Period of the field necessary to switch the vortex increases approximately from 141 ps at 300 K to 572 ps for the high-temperature limit. (ii) Amplitude of the field necessary to switch the vortex core decreases roughly from 60 mT to 15 mT - even at high temperatures this amplitude is nonzero, contrary to the case of quasi-static switching. (iii) Time span between the excitation and switching (switching time) seems not to depend on the temperature. (iv) Duration of the switching itself (movement of the Bloch point in the sample) increases from a few picoseconds at low temperatures to tens of picoseconds at high temperatures.

  14. Detailed conceptual design of a high temperature glass pH electrode for geothermal applications. Final report. Task II

    SciTech Connect

    Taylor, R.M.; Phelan, D.M.

    1980-09-01

    The performance of a pH sensor for use in hot geothermal brine was determined by laboratory tests simulating the expected conditions of use. Tests were conducted at temperatures from 21/sup 0/C to 260/sup 0/C and pressures from atmospheric to 5000 psi. Probes were constructed according to the design recommended. Deficiencies were found in the areas of seal, stem glass integrity and glass stability in hot simulated brine. Modifications of the design were made and tested, the improved versions overcoming the seal and stem glass cracking problems. A different pH glass formulation was used which improved sensor performance. Test results of the final design show that the sensor survived hot brine exposure at temperatures up to and including 200/sup 0/C, retaining its low temperature pH measuring capability. Exposure to 250/sup 0/C brine resulted in irreversible probe changes which caused sensor deterioration and failure. Comparative results are shown.

  15. High-temperature testing of high performance fiber reinforced concrete

    NASA Astrophysics Data System (ADS)

    Fořt, Jan; Vejmelková, Eva; Pavlíková, Milena; Trník, Anton; Čítek, David; Kolísko, Jiří; Černý, Robert; Pavlík, Zbyšek

    2016-06-01

    The effect of high-temperature exposure on properties of High Performance Fiber Reinforced Concrete (HPFRC) is researched in the paper. At first, reference measurements are done on HPFRC samples without high-temperature loading. Then, the HPFRC samples are exposed to the temperatures of 200, 400, 600, 800, and 1000 °C. For the temperature loaded samples, measurement of residual mechanical and basic physical properties is done. Linear thermal expansion coefficient as function of temperature is accessed on the basis of measured thermal strain data. Additionally, simultaneous difference scanning calorimetry (DSC) and thermogravimetry (TG) analysis is performed in order to observe and explain material changes at elevated temperature. It is found that the applied high temperature loading significantly increases material porosity due to the physical, chemical and combined damage of material inner structure, and negatively affects also the mechanical strength. Linear thermal expansion coefficient exhibits significant dependence on temperature and changes of material structure. The obtained data will find use as input material parameters for modelling the damage of HPFRC structures exposed to the fire and high temperature action.

  16. High Temperature Calibration Furnace System user's guide

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The High Temperature Calibration Furnace System (HTCFS) was developed by Summitec Corporation. It is a high precision instrument providing a constant temperature which can be used to calibrate high temperature thermocouples. Incorporating the many recent technological advances from the fields of optical fiber thermometry, material science, computer systems interfacing, and process control, the engineers at Summitec Corporation have been able to create a system that can reach a steady operating temperature of 1700 C. The precision for the system requires the measurement of temperature to be within 1 C in two hours and within 2 C in 24 hours. As documented, the experimental result shows that this system has been able to stay within .5 C in 5 hours. No other systems commercially available have been able to achieve such high temperature precision. This manual provides an overview of the system design, instructions for instrument setup, and operation procedures. Also included are a vendor list and the source codes for the custom-designed software.

  17. Solubility of Nd in brine

    SciTech Connect

    Khalili, F.; Symeopoulos, V.; Chen, J.F.; Choppin, G.R.

    1993-12-31

    The solubility of Nd(III) has been measured in a synthetic brine at pcH 6.4, 8.4, 10.4 and 12.4. The brine consisted predominantly of (Na+K)Cl and MgCl{sub 2}, with an ionic strength of 7.8M (9.4m). The experimental solubility is much less than that estimated from modeling of the species in solution in equilibrium with the Nd solid using S.I.T. The predominant solid compound of Nd (III) at each pcH was determined from X-ray diffraction patterns.

  18. High Temperature VARTM of Phenylethynyl Terminated Imides

    NASA Technical Reports Server (NTRS)

    Ghose, Sayata; Watson, Kent A.; Cano, Roberto J.; Britton, Sean M.; Jensen, Brian J.; Connell, John W.; Herring, Helen M.; Linberry, Quentin J.

    2009-01-01

    LaRC phenylethynyl terminated imide (PETI) resins were processed into composites using high temperature vacuum assisted resin transfer molding (VARTM). Although initial runs yielded composites with high void content, process modifications reduced voids to <3%. Photomicrographs were taken and void contents and T(sub g)s of the panels were determined.

  19. High-temperature helium-loop facility

    SciTech Connect

    Tokarz, R.D.

    1981-09-01

    The high-temperature helium loop is a facility for materials testing in ultrapure helium gas at high temperatures. The closed loop system is capable of recirculating high-purity helium or helium with controlled impurities. The gas loop maximum operating conditions are as follows: 300 psi pressure, 500 lb/h flow rate, and 2100/sup 0/F temperature. The two test sections can accept samples up to 3.5 in. diameter and 5 ft long. The gas loop is fully instrumented to continuously monitor all parameters of loop operation as well as helium impurities. The loop is fully automated to operate continuously and requires only a daily servicing by a qualified operator to replenish recorder charts and helium makeup gas. Because of its versatility and high degree of parameter control, the helium loop is applicable to many types of materials research. This report describes the test apparatus, operating parameters, peripheral systems, and instrumentation system.

  20. Study of high temperature oxide superconductors

    NASA Astrophysics Data System (ADS)

    Wu, M. K.; Ashburn, J. R.; Higgins, C. A.; Carswell, W. E.; Loo, B. H.; Burns, D. H.; Ibrahim, A.; Rolin, T.; Peters, P. N.; Sisk, R. C.

    1988-01-01

    Experimental studies are reported whose results indicate that proper processing procedures are critical to the formation of high-temperature copper oxide superconductors. Superconducting 123 films can be fabricated using the green 211 phase as a substrate. The transition temperature and transition width characteristics of these films are better than those obtained when other oxide compounds are used as substrates. A compact or single-crystal 211 phase will be desirable as a substrate for high-quality thin films. A new high T(c) copper oxide compound with nonrare earth elements was prepared using high-temperature processing. A YBa2Cu3O7-Ag composite with improved electrical conductivity was also prepared.

  1. High-temperature bulk acoustic wave sensors

    NASA Astrophysics Data System (ADS)

    Fritze, Holger

    2011-01-01

    Piezoelectric crystals like langasite (La3Ga5SiO14, LGS) and gallium orthophosphate (GaPO4) exhibit piezoelectrically excited bulk acoustic waves at temperatures of up to at least 1450 °C and 900 °C, respectively. Consequently, resonant sensors based on those materials enable new sensing approaches. Thereby, resonant high-temperature microbalances are of particular interest. They correlate very small mass changes during film deposition onto resonators or gas composition-dependent stoichiometry changes of thin films already deposited onto the resonators with the resonance frequency shift of such devices. Consequently, the objective of the work is to review the high-temperature properties, the operation limits and the measurement principles of such resonators. The electromechanical properties of high-temperature bulk acoustic wave resonators such as mechanical stiffness, piezoelectric and dielectric constant, effective viscosity and electrical conductivity are described using a one-dimensional physical model and determined accurately up to temperatures as close as possible to their ultimate limit. Insights from defect chemical models are correlated with the electromechanical properties of the resonators. Thereby, crucial properties for stable operation as a sensor under harsh conditions are identified to be the formation of oxygen vacancies and the bulk conductivity. Operation limits concerning temperature, oxygen partial pressure and water vapor pressure are given. Further, application-relevant aspects such as temperature coefficients, temperature compensation and mass sensitivity are evaluated. In addition, approximations are introduced which make the exact model handy for routine data evaluation. An equivalent electrical circuit for high-temperature resonator devices is derived based on the one-dimensional physical model. Low- and high-temperature approximations are introduced. Thereby, the structure of the equivalent circuit corresponds to the Butterworth

  2. Injection of dilute brine and crude oil/brine/rock interactions

    NASA Astrophysics Data System (ADS)

    Tang, Guoqing; Morrow, Norman R.

    Sensitivity of oil recovery to injection brine composition has been reported for a variety of circumstances including trends of increased recovery of crude oil with decrease in salinity. Absolute permeabilities of sandstones to synthetic reservoir brines and dilutions of these brines show little sensitivity to salinity when the initial brine and injected brine are of the same composition. With reservoir brine as the initial brine and injection of dilute brine, the pH of the outflow brine increased and absolute permeability to brine decreased, but never to less than 50% of its original value. Such changes, if any, were much less for rocks with low clay content. During the course of recovery of crude oil, interfacial tensions of crude oil and dilute effluent brine were reduced by about 25% relative to values for crude oil and reservoir brine. Effluent brine pH increased after injection of low salinity brine, but showed no response in the absence of an initial water saturation. Changes in brine composition resulting from flow through Berea sandstone were small. Fines production and permeability reduction resulting from injection of dilute brine was greatly reduced by the presence of crude oil.

  3. NDE standards for high temperature materials

    NASA Technical Reports Server (NTRS)

    Vary, Alex

    1991-01-01

    High temperature materials include monolithic ceramics for automotive gas turbine engines and also metallic/intermetallic and ceramic matrix composites for a range of aerospace applications. These are materials that can withstand extreme operating temperatures that will prevail in advanced high-efficiency gas turbine engines. High temperature engine components are very likely to consist of complex composite structures with three-dimensionality interwoven and various intermixed ceramic fibers. The thermomechanical properties of components made of these materials are actually created in-place during processing and fabrication stages. The complex nature of these new materials creates strong incentives for exact standards for unambiguous evaluations of defects and microstructural characteristics. NDE techniques and standards that will ultimately be applicable to production and quality control of high temperature materials and structures are still emerging. The needs range from flaw detection to below 100 micron levels in monolithic ceramics to global imaging of fiber architecture and matrix densification anomalies in composites. The needs are different depending on the processing stage, fabrication method, and nature of the finished product. The standards are discussed that must be developed in concert with advances in NDE technology, materials processing research, and fabrication development. High temperature materials and structures that fail to meet stringent specifications and standards are unlikely to compete successfully either technologically or in international markets.

  4. High-Temperature Solar Cell Development

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Raffaelle, Ryne P.; Merritt, Danielle

    2004-01-01

    The vast majority of satellites and near-earth probes developed to date have relied upon photovoltaic power generation. If future missions to probe environments close to the sun will be able to use photovoltaic power, solar cells that can function at high temperatures, under high light intensity, and high radiation conditions must be developed. For example, the equilibrium temperature of a Mercury surface station will be about 450 C, and the temperature of solar arrays on the proposed "Solar Probe" mission will extend to temperatures as high as 2000 C (although it is likely that the craft will operate on stored power rather than solar energy during the closest approach to the sun). Advanced thermal design principles, such as replacing some of the solar array area with reflectors, off-pointing, and designing the cells to reflect rather than absorb light out of the band of peak response, can reduce these operating temperature somewhat. Nevertheless, it is desirable to develop approaches to high-temperature solar cell design that can operate under temperature extremes far greater than today's cells. Solar cells made from wide bandgap (WBG) compound semiconductors are an obvious choice for such an application. In order to aid in the experimental development of such solar cells, we have initiated a program studying the theoretical and experimental photovoltaic performance of wide bandgap materials. In particular, we have been investigating the use of GaP, SiC, and GaN materials for space solar cells. We will present theoretical results on the limitations on current cell technologies and the photovoltaic performance of these wide-bandgap solar cells in a variety of space conditions. We will also give an overview of some of NASA's cell developmental efforts in this area and discuss possible future mission applications.

  5. 7 CFR 58.320 - Brine tanks.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Brine tanks. 58.320 Section 58.320 Agriculture....320 Brine tanks. Brine tanks used for the treating of parchment liners shall be constructed of... liners. The tank should also be provided with a satisfactory drainage outlet....

  6. Brine Sampling and Evaluation Program, 1991 report

    SciTech Connect

    Deal, D.E.; Abitz, R.J.; Myers, J.; Martin, M.L.; Milligan, D.J.; Sobocinski, R.W.; Lipponer, P.P.J.; Belski, D.S.

    1993-09-01

    The data presented in this report are the result of Brine Sampling and Evaluation Program (BSEP) activities at the Waste Isolation Pilot Plan (WIPP) during 1991. These BSEP activities document and investigate the origins, hydraulic characteristics, extent, and composition of brine occurrences in the Permian Salado Formation and seepage of that brine into the excavations at the WIPP. When excavations began at the WIPP in 1982, small brine seepages (weeps) were observed on the walls. Brine studies began as part of the Site Validation Program and were formalized as a program in its own right in 1985. During nine years of observations (1982--1991), evidence has mounted that the amount of brine seeping into the WIPP excavations is limited, local, and only a small fraction of that required to produce hydrogen gas by corroding the metal in the waste drums and waste inventory. The data through 1990 is discussed in detail and summarized by Deal and others (1991). The data presented in this report describes progress made during the calendar year 1991 and focuses on four major areas: (1) quantification of the amount of brine seeping across vertical surfaces in the WIPP excavations (brine ``weeps); (2) monitoring of brine inflow, e.g., measuring brines recovered from holes drilled downward from the underground drifts (downholes), upward from the underground drifts (upholes), and from subhorizontal holes; (3) further characterization of brine geochemistry; and (4) preliminary quantification of the amount of brine that might be released by squeezing the underconsolidated clays present in the Salado Formation.

  7. High temperature thrust chamber for spacecraft

    NASA Technical Reports Server (NTRS)

    Chazen, Melvin L. (Inventor); Mueller, Thomas J. (Inventor); Kruse, William D. (Inventor)

    1998-01-01

    A high temperature thrust chamber for spacecraft (20) is provided herein. The high temperature thrust chamber comprises a hollow body member (12) having an outer surface and an internal surface (16) defining the high temperature chamber (10). The body member (12) is made substantially of rhenium. An alloy (18) consisting of iridium and at least alloying metal selected of the group consisting of rhodium, platinum and palladium is deposited on at least a portion of the internal surface (16) of the body member (12). The iridium and the alloying metal are electrodeposited onto the body member (12). A HIP cycle is performed upon the body member (12) to cause the coating of iridium and the alloying metal to form the alloy (18) which protects the body member (12) from oxidation.

  8. High-temperature geothermal reservoir engineering

    SciTech Connect

    Schroeder, R.C.; Benson, S.; Goranson, C.

    1980-02-01

    A review of high-temperature geothermal reservoir engineering is presented. High-temperature downhole conditions encountered during field activities are reviewed with data from Cerro Prieto as the primary example. The types of measurements required for estimation of formation parameter values and how they depend on other geoscience data are reviewed. The analysis techniques that are currently used to evaluate field data are discussed and their limitations, applicability, and associated difficulties are described using data from Cerro Prieto as an example. Downhole tools that are needed for high-temperature measurements are discussed with a review of the current state of the art. The use of measured data in reservoir engineering simulation calculations is summarized, and different numerical models are reviewed. Data from Cerro Prieto are used as an example to show how reserves and reservoir depletion calculations can be used to aid the field developer in choosing operational field strategies.

  9. High Temperature Membrane & Advanced Cathode Catalyst Development

    SciTech Connect

    Protsailo, Lesia

    2006-04-20

    Current project consisted of three main phases and eighteen milestones. Short description of each phase is given below. Table 1 lists program milestones. Phase 1--High Temperature Membrane and Advanced Catalyst Development. New polymers and advanced cathode catalysts were synthesized. The membranes and the catalysts were characterized and compared against specifications that are based on DOE program requirements. The best-in-class membranes and catalysts were downselected for phase 2. Phase 2--Catalyst Coated Membrane (CCM) Fabrication and Testing. Laboratory scale catalyst coated membranes (CCMs) were fabricated and tested using the down-selected membranes and catalysts. The catalysts and high temperature membrane CCMs were tested and optimized. Phase 3--Multi-cell stack fabrication. Full-size CCMs with the down-selected and optimized high temperature membrane and catalyst were fabricated. The catalyst membrane assemblies were tested in full size cells and multi-cell stack.

  10. Low toxicity high temperature PMR polyimide

    NASA Technical Reports Server (NTRS)

    Pater, Ruth H. (Inventor)

    1992-01-01

    In-situ polymerization of monomer reactants (PMR) type polyimides constitute an important class of ultra high performance composite matrix resins. PMR-15 is the best known and most widely used PMR polyimide. An object of the present invention is to provide a substantially improved high temperature PMR-15 system that exhibits better processability, toughness, and thermo-oxidative stability than PMR-15, as well as having a low toxicity. Another object is to provide new PMR polyimides that are useful as adhesives, moldings, and composite matrices. By the present invention, a new PMR polyimide comprises a mixture of the following compounds: 3,4'-oxydianiline (3,4'-ODA), NE, and BTDE which are then treated with heat. This PMR was designated LaRC-RP46 and has a broader processing window, better reproducibility of high quality composite parts, better elevated temperature mechanical properties, and higher retention of mechanical properties at an elevated temperature, particularly, at 371 C.

  11. Containerless measurements on liquids at high temperatures

    NASA Technical Reports Server (NTRS)

    Weber, Richard

    1993-01-01

    The application of containerless techniques for measurements of the thermophysical properties of high temperature liquids is reviewed. Recent results obtained in the materials research laboratories at Intersonics are also presented. Work to measure high temperature liquid properties is motivated by both the need for reliable property data for modeling of industrial processes involving molten materials and generation of data form basic modeling of materials behavior. The motivation for this work and examples of variations in thermophysical property values from the literature are presented. The variations may be attributed to changes in the specimen properties caused by chemical changes in the specimen and/or to measurement errors. The two methods used to achieve containerless conditions were aeroacoustic levitation and electromagnetic levitation. Their qualities are presented. The accompanying slides show the layout of levitation equipment and present examples of levitated metallic and ceramic specimens. Containerless techniques provide a high degree of control over specimen chemistry, nucleation and allow precise control of liquid composition to be achieved. Effects of minor additions can thus be measured in a systematic way. Operation in reduced gravity enables enhanced control of liquid motion which can allow measurement of liquid transport properties. Examples of nucleation control, the thermodynamics of oxide contamination removal, and control of the chromium content of liquid aluminum oxide by high temperature containerless processes are presented. The feasibility of measuring temperature, emissivity, liquidus temperature, enthalpy, surface tension, density, viscosity, and thermal diffusivity are discussed in the final section of the paper.

  12. Evidence of methane venting and geochemistry of brines on mud volcanoes of the eastern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Charlou, J. L.; Donval, J. P.; Zitter, T.; Roy, N.; Jean-Baptiste, P.; Foucher, J. P.; Woodside, J.; Medinaut Scientific Party

    2003-08-01

    As a part of the Dutch-French MEDINAUT diving expedition in 1998, cold seeps and mud volcanoes were studied and sampled in two distinctive tectonic settings in the eastern Mediterranean Sea. The first setting was the Olimpi Mud Volcano field (OMV area), including Napoli, Milano, Maidstone and Moscow mud volcanoes, south of Crete on the Mediterranean ridge. The second setting was the Anaximander Mountains (AM area), southwestern Turkey, where Amsterdam, Kazan and Kula mud volcanoes were explored. Large methane concentrations (45-892 nmol/kg) were measured in the water column not only above mud volcanoes but also in seeps and vents along related fault systems, indicating intense degassing related to fluid circulation in sediments. The tracer results show that there is considerable variability in terms of gas seepage and matter flux between these mud volcanoes. Brine accumulations found as shallow pools on Napoli or associated with deep faults (Nadir Lake) outside mud volcanoes exhibit variable chlorinity, mineral and gas composition. The brines are significantly enriched in δ18O relative to ambient seawater and are consistent with evaporated seawater. In the Nadir Brine Lake, the level of methane is as high as 5.93 mmol/kg, lower than the methane saturation level of 120 mmol/kg theoretically found at the salinity (120), pressure (200 bar), and temperature (13.6°C) conditions of Nadir lake. In contrast, the shallow brine pools on Napoli mud volcano (also OMV area) have methane levels of only 4.45 μmol/kg. In all brines, helium data show a clear radiogenic isotopic ratio ( R=0.06× Ra), in excellent agreement with recently published data for the Urania basin. Methane to ethane ratios (>1000) and δ13C(CH 4) values (-65.6‰PDB) indicate that the CH 4 is microbially produced. Unlike mid-ocean ridges, where abiogenic methane and helium have a common origin in the brines, the large variation in the CH 4/He ratio indicates that CH 4 and helium sources are unrelated, a

  13. Micromechanics of high temperature deformation and failure

    NASA Technical Reports Server (NTRS)

    Nasser, S. N.; Weertman, J. R.

    1985-01-01

    The micromechanics of the constitutive behavior of elastoplastic materials at high temperatures was examined. The experimental work focused on the development of microscopic defects in superalloys (Waspaloy), especially the formation of voids at grain boundary carbides, and slip induced surface cracks within grains upon cyclic loading at high temperatures. The influence of these defects on the life expectancy of the material was examined. The theoretical work consists of two parts: (1) analytical description of the mechanisms that lead to defects observed experimentally; and (2) development of macroscopic elastoplastic nonlinear constitutive relations based on mechanical modeling.

  14. Joining of ceramics for high temperature applications

    NASA Technical Reports Server (NTRS)

    Vilpas, Martti

    1987-01-01

    Summarized is a literature survey of the methods for joining ceramics to ceramics or ceramics to metals for high temperature applications. Also mechanical properties and potential applications of the joints are considered. The joining of ceramics is usually carried out by brazing or diffusion bonding. Especially the latter has been found useful, increasing the application of bonded ceramics. The possibility of using electron beam and laser beam welding for joining ceramics has also recently been investigated. The bonding of ceramics has found numerous applications typical for high operating temperatures, i.e., sensors and thermocouples.

  15. Introduction to high-temperature superconductivity

    SciTech Connect

    Sheahen, T.P.

    1994-12-31

    The Electric Power Research Institute, as part of its program to develop high-temperature superconductivity applications for the power industry, has endevoured to educate utility engineers and executives on superconductivity. This book is a series of tutorials prepared by the Argonne National Laboratory. Part one is at an introductory level, asking and answering the question `What is superconductivity?` Part 2 is an exposition of the basic properties of the new materials - structure, phase equilibria, effects of doping, etc. with consideration of theoretical issues. Part 3 covers potential practical uses of high temperature superconductors.

  16. High-temperature MAS-NMR at high spinning speeds.

    PubMed

    Kirchhain, Holger; Holzinger, Julian; Mainka, Adrian; Spörhase, Andreas; Venkatachalam, Sabarinathan; Wixforth, Achim; van Wüllen, Leo

    2016-09-01

    A low cost version to enable high temperature MAS NMR experiments at temperatures of up to 700°C and spinning speeds of up to 10kHz is presented. The method relies on inductive heating using a metal coated rotor insert. The metal coating is accomplished via a two step process involving physical vapor deposition and galvanization.

  17. NICE3: Textile Brine Separation

    SciTech Connect

    Recca, L.

    1999-01-29

    The goal of this project is to demonstrate the significant energy and waste savings that can be realized by using nanofiltration technology to reuse textile dyebath brines. Read this new fact sheet to learn how this new membrane technology can benefit your business.

  18. Great Salt Lake, Utah: chemical and physical variations of the brine, 1963-1966

    USGS Publications Warehouse

    Hahl, D.C.; Handy, A.H.

    1969-01-01

    the zone below 16 feet in the south end of the lake. The shallow zone of brine in the southern part of the lake varies in concentration of dissolved solids from season to season because of the interplay between inflow and evaporation. Brine in this zone is usually the most dilute of any brine in the lake. The two deep brines in the southern part of the lake contain almost the same concentration of dissolved solids, which is greater than that of brine in the shallow zone but not quite as great as that of brine north of the causeway. The concentrations of dissolved solids of the deep brines also vary seasonally. Brine in the deep zone near the south side of the causeway is maintained by a density current that flows at depth from the northern part of the lake through the causeway. Brine in the deep zone at the south end of the lake is distinguished from the three other brines in the lake by its high concentration of sodium ion and its low concentration of sulfate ion. This brine might result from the inflow of ground water through the zone of sulfate reduction at the lakebed. Brine north of the causeway is reddish-brown and visibility of an object placed in it is limited to about 2 feet, whereas brine south of the causeway is green and bottom features 15 feet below the surface can often be clearly seen. Studies describing the relations among the interchange of brine through the causeway, the thickness of the salt crust, the concentrations of dissolved solids in the brine, and identifying the source of deep brine at the south end would provide information needed for future lake management.

  19. Fiber Bragg Grating Filter High Temperature Sensors

    NASA Technical Reports Server (NTRS)

    Lyons, Donald R.; Brass, Eric D.; Pencil, Eric (Technical Monitor)

    2001-01-01

    We present a scaled-down method for determining high temperatures using fiber-based Bragg gratings. Bragg gratings are distributed along the length of the optical fiber, and have high reflectivities whenever the optical wavelength is twice the grating spacing. These spatially distinct Bragg regions (located in the core of a fiber) are sensitive to local temperature changes. Since these fibers are silica-based they are easily affected by localized changes in temperature, which results in changes to both the grating spacing and the wavelength reflectivity. We exploit the shift in wavelength reflectivity to measure the change in the local temperature. Note that the Bragg region (sensing area) is some distance away from where the temperature is being measured. This is done so that we can measure temperatures that are much higher than the damage threshold of the fiber. We do this by affixing the fiber with the Bragg sensor to a material with a well-known coefficient of thermal expansion, and model the heat gradient from the region of interest to the actual sensor. The research described in this paper will culminate in a working device as well as be the second portion of a publication pending submission to Optics Letters.

  20. Light Scattering on the High Temperature Superconductors

    NASA Astrophysics Data System (ADS)

    Slakey, Francis

    The high temperature superconductors have been examined by the technique of Raman scattering in several limits: the insulating phase, the normal and superconducting state of the superconducting phase, and an optically induced metastable phase. In all cases, the analysis and proposed phenomenological models involved either an examination of the inelastic background scattering or the phonon excitation spectrum. Specifically, the character, temperature dependence, critical temperature dependence and the copper-oxygen covalency dependence of the inelastic background scattering has been studied in all three phases. Analysis of the superconducting phase reveals a marginal Fermi-liquid like character of the electronic polarizability, and a decidedly non-traditional shift of the scattering intensity of the electronic excitations at low temperature. On removing oxygen, the system passes through a metal-insulator transition and the inelastic background becomes dominantly magnetic in origin. Examinations of the 'allowed' Raman active phonons in the superconducting phase expose a strong coupling of two modes to the background electronic excitation spectrum, and a dramatic renormalization of these modes below T _{rm c}. Further, two sharply resonant Raman 'forbidden' modes can be bleached out of the spectrum at low temperature with a sufficiently high laser dosage. A transition from this optically induced metastable state to the normal state occurs on warming the crystal back to room temperature. On reducing the oxygen concentration, the coupling strength of the two asymmetric phonons diminishes rapidly, the renormalization effects vanish, and the compound no longer exhibits metastability.

  1. High Temperature Mechanisms for Venus Exploration

    NASA Astrophysics Data System (ADS)

    Ji, Jerri; Narine, Roop; Kumar, Nishant; Singh, Sase; Gorevan, Steven

    Future Venus missions, including New Frontiers Venus In-Situ Explorer and three Flagship Missions - Venus Geophysical Network, Venus Mobile Explorer and Venus Surface Sample Return all focus on searching for evidence of past climate change both on the surface and in the atmospheric composition as well as in the interior dynamics of the planet. In order to achieve these goals and objectives, many key technologies need to be developed for the Venus extreme environment. These key technologies include sample acquisition systems and other high-temperature mechanisms and mobility systems capable of extended operation when directly exposed to the Venus surface or lower atmosphere environment. Honeybee Robotics has developed two types of high temperature motors, the materials and components in both motors were selected based on the requirement to survive temperatures above a minimum of 460° C, at earth atmosphere. The prototype Switched Reluctance Motor (SRM) has been operated non-continuously for over 20 hours at Venus-like conditions (460° C temperature, mostly CO2 gas environment) and it remains functional. A drilling system, actuated by two SRMs was tested in Venus-like conditions, 460° C temperature and mostly CO2 gas environment, for more than 15 hours. The drill successfully completed three tests by drilling into chalk up to 6 inches deep in each test. A first generation Brushless DC (BLDC) Motor and high temperature resolver were also tested and the feasibility of the designs was demonstrated by the extended operation of both devices under Venus-like condition. Further development of the BLDC motor and resolver continues and these devices will, ultimately, be integrated into the development of a high temperature sample acquisition scoop and high temperature joint (awarded SBIR Phase II in October, 2007). Both the SR and BLDC motors will undergo extensive testing at Venus temperature and pressure (TRL6) and are expected to be mission ready before the next New

  2. High-Temperature Capacitor Polymer Films

    NASA Astrophysics Data System (ADS)

    Tan, Daniel; Zhang, Lili; Chen, Qin; Irwin, Patricia

    2014-12-01

    Film capacitor technology has been under development for over half a century to meet various applications such as direct-current link capacitors for transportation, converters/inverters for power electronics, controls for deep well drilling of oil and gas, direct energy weapons for military use, and high-frequency coupling circuitry. The biaxially oriented polypropylene film capacitor remains the state-of-the-art technology; however, it is not able to meet increasing demand for high-temperature (>125°C) applications. A number of dielectric materials capable of operating at high temperatures (>140°C) have attracted investigation, and their modifications are being pursued to achieve higher volumetric efficiency as well. This paper highlights the status of polymer dielectric film development and its feasibility for capacitor applications. High-temperature polymers such as polyetherimide (PEI), polyimide, and polyetheretherketone were the focus of our studies. PEI film was found to be the preferred choice for high-temperature film capacitor development due to its thermal stability, dielectric properties, and scalability.

  3. High temperature experiment for accelerator inertial fusion

    SciTech Connect

    Lee, E.P.

    1985-05-01

    The High Temperature Experiment (HTE) is intended to produce temperatures of 50 to 100 eV in solid density targets driven by heavy ion beams from a multiple beam induction linac. The fundamental variables (particle species, energy, number of beamlets, current and pulse length) must be fixed to achieve the temperature at minimum cost, subject to criteria of technical feasibility and relevance to the development of a Fusion Driver. The conceptual design begins with an assumed (radiation-limited) target temperature and uses limitations due to particle range, beamlet perveance, and target disassembly to bound the allowable values of mass number (A) and energy (E). An accelerator model is then applied to determine the minimum length accelerator, which is a guide to total cost. The accelerator model takes into account limits on transportable charge, maximum gradient, core mass per linear meter, and head-to-tail momentum variation within a pulse.

  4. High-Temperature Shape Memory Polymers

    NASA Technical Reports Server (NTRS)

    Yoonessi, Mitra; Weiss, Robert A.

    2012-01-01

    physical conformation changes when exposed to an external stimulus, such as a change in temperature. Such materials have a permanent shape, but can be reshaped above a critical temperature and fixed into a temporary shape when cooled under stress to below the critical temperature. When reheated above the critical temperature (Tc, also sometimes called the triggering or switching temperature), the materials revert to the permanent shape. The current innovation involves a chemically treated (sulfonated, carboxylated, phosphonated, or other polar function group), high-temperature, semicrystalline thermoplastic poly(ether ether ketone) (Tg .140 C, Tm = 340 C) mix containing organometallic complexes (Zn++, Li+, or other metal, ammonium, or phosphonium salts), or high-temperature ionic liquids (e.g. hexafluorosilicate salt with 1-propyl-3- methyl imidazolium, Tm = 210 C) to form a network where dipolar or ionic interactions between the polymer and the low-molecular-weight or inorganic compound forms a complex that provides a physical crosslink. Hereafter, these compounds will be referred to as "additives". The polymer is semicrystalline, and the high-melt-point crystals provide a temporary crosslink that acts as a permanent crosslink just so long as the melting temperature is not exceeded. In this example case, the melting point is .340 C, and the shape memory critical temperature is between 150 and 250 C. PEEK is an engineering thermoplastic with a high Young fs modulus, nominally 3.6 GPa. An important aspect of the invention is the control of the PEEK functionalization (in this example, the sulfonation degree), and the thermal properties (i.e. melting point) of the additive, which determines the switching temperature. Because the compound is thermoplastic, it can be formed into the "permanent" shape by conventional plastics processing operations. In addition, the compound may be covalently cross - linked after forming the permanent shape by S-PEEK by applying ionizing

  5. Research at Very High Pressures and High Temperatures

    ERIC Educational Resources Information Center

    Bundy, Francis P.

    1977-01-01

    Reviews research and apparatus utilized in the study of the states and characteristics of materials at very high temperatures and pressures. Includes three examples of the research being conducted. (SL)

  6. Bimodular high temperature planar oxygen gas sensor.

    PubMed

    Sun, Xiangcheng; Liu, Yixin; Gao, Haiyong; Gao, Pu-Xian; Lei, Yu

    2014-01-01

    A bimodular planar O2 sensor was fabricated using NiO nanoparticles (NPs) thin film coated yttria-stabilized zirconia (YSZ) substrate. The thin film was prepared by radio frequency (r.f.) magnetron sputtering of NiO on YSZ substrate, followed by high temperature sintering. The surface morphology of NiO NPs film was characterized by atomic force microscope (AFM) and scanning electron microscope (SEM). X-ray diffraction (XRD) patterns of NiO NPs thin film before and after high temperature O2 sensing demonstrated that the sensing material possesses a good chemical and structure stability. The oxygen detection experiments were performed at 500, 600, and 800°C using the as-prepared bimodular O2 sensor under both potentiometric and resistance modules. For the potentiometric module, a linear relationship between electromotive force (EMF) output of the sensor and the logarithm of O2 concentration was observed at each operating temperature, following the Nernst law. For the resistance module, the logarithm of electrical conductivity was proportional to the logarithm of oxygen concentration at each operating temperature, in good agreement with literature report. In addition, this bimodular sensor shows sensitive, reproducible and reversible response to oxygen under both sensing modules. Integration of two sensing modules into one sensor could greatly enrich the information output and would open a new venue in the development of high temperature gas sensors. PMID:25191652

  7. Bimodular high temperature planar oxygen gas sensor

    PubMed Central

    Sun, Xiangcheng; Liu, Yixin; Gao, Haiyong; Gao, Pu-Xian; Lei, Yu

    2014-01-01

    A bimodular planar O2 sensor was fabricated using NiO nanoparticles (NPs) thin film coated yttria-stabilized zirconia (YSZ) substrate. The thin film was prepared by radio frequency (r.f.) magnetron sputtering of NiO on YSZ substrate, followed by high temperature sintering. The surface morphology of NiO NPs film was characterized by atomic force microscope (AFM) and scanning electron microscope (SEM). X-ray diffraction (XRD) patterns of NiO NPs thin film before and after high temperature O2 sensing demonstrated that the sensing material possesses a good chemical and structure stability. The oxygen detection experiments were performed at 500, 600, and 800°C using the as-prepared bimodular O2 sensor under both potentiometric and resistance modules. For the potentiometric module, a linear relationship between electromotive force (EMF) output of the sensor and the logarithm of O2 concentration was observed at each operating temperature, following the Nernst law. For the resistance module, the logarithm of electrical conductivity was proportional to the logarithm of oxygen concentration at each operating temperature, in good agreement with literature report. In addition, this bimodular sensor shows sensitive, reproducible and reversible response to oxygen under both sensing modules. Integration of two sensing modules into one sensor could greatly enrich the information output and would open a new venue in the development of high temperature gas sensors. PMID:25191652

  8. Direct observation of the evolution of a seafloor 'black smoker' from vapor to brine

    USGS Publications Warehouse

    Von Damm, K. L.; Buttermore, L.G.; Oosting, S.E.; Bray, A.M.; Fornari, D.J.; Lilley, M.D.; Shanks, Wayne C.

    1997-01-01

    A single hydrothermal vent, 'F' vent, occurring on very young crust at 9??16.8???N, East Pacific Rise, was sampled in 1991 and 1994. In 1991, at the measured temperature of 388??C and seafloor pressure of 258 bar, the fluids from this vent were on the two-phase curve for seawater. These fluids were very low in chlorinity and other dissolved species, and high in gases compared to seawater and most sampled seafloor hydrothermal vent fluids. In 1994, when this vent was next sampled, it had cooled to 351??C and was venting fluids ???1.5 times seawater chlorinity. This is the first reported example of a single seafloor hydrothermal vent evolving from vapor to brine. The 1991 and 1994 fluids sampled from this vent are compositionally conjugate pairs to one another. These results support the hypothesis that vapor-phase fluids vent in the early period following a volcanic eruption, and that the liquid-phase brines are stored within the oceanic crust, and vent at a later time, in this case 3 years. These results demonstrate that the venting of brines can occur in the same location, in fact from the same sulfide edifice, where the vapor-phase fluids vented previously.

  9. High Summer Temperatures and Mortality in Estonia

    PubMed Central

    Oudin Åström, Daniel; Åström, Christofer; Rekker, Kaidi; Indermitte, Ene; Orru, Hans

    2016-01-01

    Background On-going climate change is predicted to result in a growing number of extreme weather events—such as heat waves—throughout Europe. The effect of high temperatures and heat waves are already having an important impact on public health in terms of increased mortality, but studies from an Estonian setting are almost entirely missing. We investigated mortality in relation to high summer temperatures and the time course of mortality in a coastal and inland region of Estonia. Methods We collected daily mortality data and daily maximum temperature for a coastal and an inland region of Estonia. We applied a distributed lag non-linear model to investigate heat related mortality and the time course of mortality in Estonia. Results We found an immediate increase in mortality associated with temperatures exceeding the 75th percentile of summer maximum temperatures, corresponding to approximately 23°C. This increase lasted for a couple of days in both regions. The total effect of elevated temperatures was not lessened by significant mortality displacement. Discussion We observed significantly increased mortality in Estonia, both on a country level as well as for a coastal region and an inland region with a more continental climate. Heat related mortality was higher in the inland region as compared to the coastal region, however, no statistically significant differences were observed. The lower risks in coastal areas could be due to lower maximum temperatures and cooling effects of the sea, but also better socioeconomic condition. Our results suggest that region specific estimates of the impacts of temperature extremes on mortality are needed. PMID:27167851

  10. High-Temperature Adhesive Strain Gage Developed

    NASA Technical Reports Server (NTRS)

    Pereira, J. Michael; Roberts, Gary D.

    1997-01-01

    Researchers at the NASA Lewis Research Center have developed a unique strain gage and adhesive system for measuring the mechanical properties of polymers and polymer composites at elevated temperatures. This system overcomes some of the problems encountered in using commercial strain gages and adhesives. For example, typical commercial strain gage adhesives require a postcure at temperatures substantially higher than the maximum test temperature. The exposure of the specimen to this temperature may affect subsequent results, and in some cases may be higher than the glass-transition temperature of the polymer. In addition, although typical commercial strain gages can be used for short times at temperatures up to 370 C, their long-term use is limited to 230 C. This precludes their use for testing some high-temperature polyimides near their maximum temperature capability. Lewis' strain gage and adhesive system consists of a nonencapsulated, unbacked gage grid that is bonded directly to the polymer after the specimen has been cured but prior to the normal postcure cycle. The gage is applied with an adhesive specially formulated to cure under the specimen postcure conditions. Special handling, mounting, and electrical connection procedures were developed, and a fixture was designed to calibrate each strain gage after it was applied to a specimen. A variety of tests was conducted to determine the performance characteristics of the gages at elevated temperatures on PMR-15 neat resin and titanium specimens. For these tests, which included static tension, thermal exposure, and creep tests, the gage and adhesive system performed within normal strain gage specifications at 315 C. An example of the performance characteristics of the gage can be seen in the figure, which compares the strain gage measurement on a polyimide specimen at 315 C with an extensometer measurement.

  11. Two High-Temperature Foil Journal Bearings

    NASA Technical Reports Server (NTRS)

    Zak, Michail

    2006-01-01

    An enlarged, high-temperature-compliant foil bearing has been built and tested to demonstrate the feasibility of such bearings for use in aircraft gas turbine engines. Foil bearings are attractive for use in some machines in which (1) speeds of rotation, temperatures, or both exceed maximum allowable values for rolling-element bearings; (2) conventional lubricants decompose at high operating temperatures; and/or (3) it is necessary or desirable not to rely on conventional lubrication systems. In a foil bearing, the lubricant is the working fluid (e.g., air or a mixture of combustion gases) in the space between the journal and the shaft in the machine in which the bearing is installed.

  12. Gravimeter using high-temperature superconductor bearing.

    SciTech Connect

    Hull, J. R.

    1998-09-11

    We have developed a sensitive gravimeter concept that uses an extremely low-friction bearing based on a permanent magnet (PM) levitated over a high-temperature superconductor (HTS). A mass is attached to the PM by means of a cantilevered beam, and the combination of PM and HTS forms a bearing platform that has low resistance to rotational motion but high resistance to horizontal, vertical, or tilting motion. The combination acts as a low-loss torsional pendulum that can be operated in any orientation. Gravity acts on the cantilevered beam and attached mass, accelerating them. Variations in gravity can be detected by time-of-flight acceleration, or by a control coil or electrode that would keep the mass stationary. Calculations suggest that the HTS gravimeter would be as sensitive as present-day superconducting gravimeters that need cooling to liquid helium temperatures, but the HTS gravimeter needs cooling only to liquid nitrogen temperatures.

  13. High Temperature Materials Interim Data Qualification Report

    SciTech Connect

    Nancy Lybeck

    2010-08-01

    ABSTRACT Projects for the very high temperature reactor (VHTR) Technology Development Office provide data in support of Nuclear Regulatory Commission licensing of the VHTR. Fuel and materials to be used in the reactor are tested and characterized to quantify performance in high temperature and high fluence environments. The VHTR program has established the NGNP Data Management and Analysis System (NDMAS) to ensure that VHTR data are qualified for use, stored in a readily accessible electronic form, and analyzed to extract useful results. This document focuses on the first NDMAS objective. It describes the High Temperature Materials characterization data stream, the processing of these data within NDMAS, and reports the interim FY2010 qualification status of the data. Data qualification activities within NDMAS for specific types of data are determined by the data qualification category assigned by the data generator. The High Temperature Materials data are being collected under NQA-1 guidelines, and will be qualified data. For NQA-1 qualified data, the qualification activities include: (1) capture testing, to confirm that the data stored within NDMAS are identical to the raw data supplied, (2) accuracy testing to confirm that the data are an accurate representation of the system or object being measured, and (3) documenting that the data were collected under an NQA-1 or equivalent Quality Assurance program. Currently, data from two test series within the High Temperature Materials data stream have been entered into the NDMAS vault: 1. Tensile Tests for Sm (i.e., Allowable Stress) Confirmatory Testing – 1,403,994 records have been inserted into the NDMAS database. Capture testing is in process. 2. Creep-Fatigue Testing to Support Determination of Creep-Fatigue Interaction Diagram – 918,854 records have been processed and inserted into the NDMAS database. Capture testing is in process.

  14. High pressure and high temperature behaviour of ZnO

    SciTech Connect

    Thakar, Nilesh A.; Bhatt, Apoorva D.; Pandya, Tushar C.

    2014-04-24

    The thermodynamic properties with the wurtzite (B4) and rocksalt (B1) phases of ZnO under high pressures and high temperatures have been investigated using Tait's Equation of state (EOS). The effects of pressures and temperatures on thermodynamic properties such as bulk modulus, thermal expansivity and thermal pressure are explored for both two structures. It is found that ZnO material gradually softens with increase of temperature while it hardens with the increment of the pressure. Our predicted results of thermodynamics properties for both the phases of ZnO are in overall agreement with the available data in the literature.

  15. Enamel for high-temperature superalloys

    NASA Technical Reports Server (NTRS)

    Levin, H.; Lent, W. E.

    1977-01-01

    Desired optical and high temperature enamel properties are obtained with glasses prepared from the system Li2O-ZrO2-nSiO2. Molar compositions range from n=4 to n=1.3, to which are added minor amounts in varying combinations of alumina, alkali fluorides, boric oxide, alkali oxides, and akaline earth oxides.

  16. 10.3 High-temperature Instrumentation

    NASA Technical Reports Server (NTRS)

    Piazza, Anthony

    2008-01-01

    This viewgraph presentation describes high temperature instrumentation development from 1960-1970, 1980-1990 and 2000-present. The contents include: 1) Background; 2) Objective; 3) Application and Sensor; 4) Attachment Techniques; 5) Evaluation/Characterization Testing; and 6) Future testing.

  17. Progress in advanced high temperature materials technology

    NASA Technical Reports Server (NTRS)

    Freche, J. C.; Ault, G. M.

    1976-01-01

    Significant progress has recently been made in many high temperature material categories pertinent to such applications by the industrial community. These include metal matrix composites, superalloys, directionally solidified eutectics, coatings, and ceramics. Each of these material categories is reviewed and the current state-of-the-art identified, including some assessment, when appropriate, of progress, problems, and future directions.

  18. High temperature pressure coupled ultrasonic waveguide

    DOEpatents

    Caines, Michael J.

    1983-01-01

    A pressure coupled ultrasonic waveguide is provided to which one end may be attached a transducer and at the other end a high temperature material for continuous ultrasonic testing of the material. The ultrasonic signal is coupled from the waveguide into the material through a thin, dry copper foil.

  19. Lightweight High-Temperature Thermal Insulation

    NASA Technical Reports Server (NTRS)

    Wagner, W. R.; Fasheh, J. I.

    1985-01-01

    Fine Ni/Cr fibers sintered into corrosion-resistant, fireproof batt. Possible applications include stoves, furnaces, safes, fire clothing, draperies in public buildings, wall firebreaks, airplane walls, and jetengine components. New insulation takes advantage of some of same properties of nickel/chromium alloy useful in heating elements in toasters, namely, corrosion and oxidation resistance even at high temperatures.

  20. Space applications of high temperature superconductivity technology

    NASA Technical Reports Server (NTRS)

    Connolly, D. J.; Aron, P. R.; Leonard, R. F.; Wintucky, E. G.

    1991-01-01

    A review is presented of the present status of high temperature superconductivity (HTS) technology and related areas of potential space application. Attention is given to areas of application that include microwave communications, cryogenic systems, remote sensing, and space propulsion and power. Consideration is given to HTS phase shifters, miniaturization of microwave filters, far-IR bolometers, and magnetic refrigeration using flux compression.

  1. Improved high-temperature silicide coatings

    NASA Technical Reports Server (NTRS)

    Klopp, W. D.; Stephens, J. R.; Stetson, A. R.; Wimber, R. T.

    1969-01-01

    Special technique for applying silicide coatings to refractory metal alloys improves their high-temperature protective capability. Refractory metal powders mixed with a baked-out organic binder and sintered in a vacuum produces a porous alloy layer on the surface. Exposing the layer to hot silicon converts it to a silicide.

  2. High-temperature corrosion in halogen environments

    SciTech Connect

    McNallan, M. )

    1994-09-01

    Halogen contaminants, particularly chlorine and fluorine, cause accelerated corrosion in such high-temperature systems as waste incinerators and waste heat recuperators on metallurgical furnaces. The mechanisms by which these phenomena occur are reviewed and discussed with the goal of identifying appropriate corrosion control strategies for materials that operate in these environments.

  3. High temperature oxidation resistant cermet compositions

    NASA Technical Reports Server (NTRS)

    Phillips, W. M. (Inventor)

    1976-01-01

    Cermet compositions are designed to provide high temperature resistant refractory coatings on stainless steel or molybdenum substrates. A ceramic mixture of chromium oxide and aluminum oxide form a coating of chromium oxide as an oxidation barrier around the metal particles, to provide oxidation resistance for the metal particles.

  4. High Temperature Langasite SAW Oxygen Sensor

    SciTech Connect

    Zheng, Peng; Chin, Tao-Lun; Greve, David; Oppenheim, Irving; Malone, Vanessa; Cao, Limin

    2011-08-01

    High-temperature langasite SAW oxygen sensors using sputtered ZnO as a resistive gas-sensing layer were fabricated and tested. Sensitivity to oxygen gas was observed between 500°C to 700°C, with a sensitivity peak at about 625°C, consistent with the theoretical predictions of the acoustoelectric effect.

  5. High temperature well bore cement slurry

    SciTech Connect

    Nahm, J.J.W.; Vinegar, H.J.; Karanikas, J.M.; Wyant, R.E.

    1993-07-13

    A low density well bore cement slurry composition is described suitable for cementing well bores with high reservoir temperatures comprising: (a) a high alumina cement in an amount of about 40 pounds per barrel of slurry or greater: (b) graphite in an amount greater than about one quarter, by volume, of the solids in the cement slurry; and (c) and a carrier fluid comprising drilling mud.

  6. Impact of the brine from a desalination plant on a shallow seagrass ( Posidonia oceanica) meadow

    NASA Astrophysics Data System (ADS)

    Gacia, Esperança; Invers, Olga; Manzanera, Marta; Ballesteros, Enric; Romero, Javier

    2007-05-01

    Although seawater desalination has increased significantly over recent decades, little attention has been paid to the impact of the main by-product (hypersaline water: brine) on ecosystems. In the Mediterranean, potentially the most affected ecosystems are meadows of the endemic seagrass Posidonia oceanica. We studied the effect of brine on a shallow P. oceanica meadow exposed to reverse osmosis brine discharge for more than 6 years. P. oceanica proved to be very sensitive to both eutrophication and high salinities derived from the brine discharge. Affected plants showed high epiphyte load and nitrogen content in the leaves, high frequencies of necrosis marks, low total non-structural carbohydrates and low glutamine synthetase activity, compared to control plants. However, there was no indication of extensive decline of the affected meadow. This is probably due to its very shallow situation, which results in high incident radiation as well as fast dilution and dispersion of the brine plume.

  7. Urania vapor composition at very high temperatures

    SciTech Connect

    Pflieger, Rachel; Colle, Jean-Yves; Iosilevskiy, Igor; Sheindlin, Michael

    2011-02-01

    Due to the chemically unstable nature of uranium dioxide its vapor composition at very high temperatures is, presently, not sufficiently studied though more experimental knowledge is needed for risk assessment of nuclear reactors. We used laser vaporization coupled to mass spectrometry of the produced vapor to study urania vapor composition at temperatures in the vicinity of its melting point and higher. The very good agreement between measured melting and freezing temperatures and between partial pressures measured on the temperature increase and decrease indicated that the change in stoichiometry during laser heating was very limited. The evolutions with temperature (in the range 2800-3400 K) of the partial pressures of the main vapor species (UO{sub 2}, UO{sub 3}, and UO{sub 2}{sup +}) were compared with theoretically predicted evolutions for equilibrium noncongruent gas-liquid and gas-solid phase coexistences and showed very good agreement. The measured main relative partial pressure ratios around 3300 K all agree with calculated values for total equilibrium between condensed and vapor phases. It is the first time the three main partial pressure ratios above stoichiometric liquid urania have been measured at the same temperature under conditions close to equilibrium noncongruent gas-liquid phase coexistence.

  8. High temperature annealing of ion irradiated tungsten

    SciTech Connect

    Ferroni, Francesco; Yi, Xiaoou; Fitzgerald, Steven P.; Edmondson, Philip D.; Roberts, Steve G.

    2015-03-21

    In this study, transmission electron microscopy of high temperature annealing of pure tungsten irradiated by self-ions was conducted to elucidate microstructural and defect evolution in temperature ranges relevant to fusion reactor applications (500–1200°C). Bulk isochronal and isothermal annealing of ion irradiated pure tungsten (2 MeV W+ ions, 500°C, 1014 W+/cm2) with temperatures of 800, 950, 1100 and 1400°C, from 0.5 to 8 h, was followed by ex situ characterization of defect size, number density, Burgers vector and nature. Loops with diameters larger than 2–3 nm were considered for detailed analysis, among which all loops had View the MathML source and were predominantly of interstitial nature. In situ annealing experiments from 300 up to 1200°C were also carried out, including dynamic temperature ramp-ups. These confirmed an acceleration of loop loss above 900°C. At different temperatures within this range, dislocations exhibited behaviour such as initial isolated loop hopping followed by large-scale rearrangements into loop chains, coalescence and finally line–loop interactions and widespread absorption by free-surfaces at increasing temperatures. An activation energy for the annealing of dislocation length was obtained, finding Ea=1.34±0.2 eV for the 700–1100°C range.

  9. High temperature annealing of ion irradiated tungsten

    DOE PAGESBeta

    Ferroni, Francesco; Yi, Xiaoou; Arakawa, Kazuto; Fitzgerald, Steven P.; Edmondson, Philip D.; Roberts, Steve G.

    2015-03-21

    In this study, transmission electron microscopy of high temperature annealing of pure tungsten irradiated by self-ions was conducted to elucidate microstructural and defect evolution in temperature ranges relevant to fusion reactor applications (500–1200°C). Bulk isochronal and isothermal annealing of ion irradiated pure tungsten (2 MeV W+ ions, 500°C, 1014 W+/cm2) with temperatures of 800, 950, 1100 and 1400°C, from 0.5 to 8 h, was followed by ex situ characterization of defect size, number density, Burgers vector and nature. Loops with diameters larger than 2–3 nm were considered for detailed analysis, among which all loops had View the MathML source andmore » were predominantly of interstitial nature. In situ annealing experiments from 300 up to 1200°C were also carried out, including dynamic temperature ramp-ups. These confirmed an acceleration of loop loss above 900°C. At different temperatures within this range, dislocations exhibited behaviour such as initial isolated loop hopping followed by large-scale rearrangements into loop chains, coalescence and finally line–loop interactions and widespread absorption by free-surfaces at increasing temperatures. An activation energy for the annealing of dislocation length was obtained, finding Ea=1.34±0.2 eV for the 700–1100°C range.« less

  10. High temperature furnace modeling and performance verifications

    NASA Technical Reports Server (NTRS)

    Smith, James E., Jr.

    1992-01-01

    Analytical, numerical, and experimental studies were performed on two classes of high temperature materials processing sources for their potential use as directional solidification furnaces. The research concentrated on a commercially available high temperature furnace using a zirconia ceramic tube as the heating element and an Arc Furnace based on a tube welder. The first objective was to assemble the zirconia furnace and construct parts needed to successfully perform experiments. The 2nd objective was to evaluate the zirconia furnace performance as a directional solidification furnace element. The 3rd objective was to establish a data base on materials used in the furnace construction, with particular emphasis on emissivities, transmissivities, and absorptivities as functions of wavelength and temperature. A 1-D and 2-D spectral radiation heat transfer model was developed for comparison with standard modeling techniques, and were used to predict wall and crucible temperatures. The 4th objective addressed the development of a SINDA model for the Arc Furnace and was used to design sample holders and to estimate cooling media temperatures for the steady state operation of the furnace. And, the 5th objective addressed the initial performance evaluation of the Arc Furnace and associated equipment for directional solidification. Results of these objectives are presented.

  11. High temperature intermetallic binders for HVOF carbides

    SciTech Connect

    Shaw, K.G.; Gruninger, M.F.; Jarosinski, W.J.

    1994-12-31

    Gas turbines technology has a long history of employing the desirable high temperature physical attributes of ceramic-metallic (cermet) materials. The most commonly used coatings incorporate combinations of WC-Co and Cr{sub 3}C{sub 2}-NiCr, which have also been successfully utilized in other non-turbine coating applications. Increased turbine operating temperatures and other high temperature service conditions have made apparent the attractive notion of increasing the temperature capability and corrosion resistance of these coatings. In this study the intermetallic binder NiAl has been used to replace the cobalt and NiCr constituents of conventional WC and Cr{sub 3}C{sub 2} cermet powders. The composite carbide thermal spray powders were fabricated for use in the HVOF coating process. The structure of HVOF deposited NiAl-carbide coatings are compared directly to the more familiar WC-Co and Cr{sub 3}C{sub 2}-NiCr coatings using X-ray diffraction, back-scattered electron imaging (BEI) and electron dispersive spectroscopy (EDS). Hardness variations with temperature are reported and compared between the NiAl and Co/NiCr binders.

  12. Advanced high temperature thermoelectrics for space power

    NASA Technical Reports Server (NTRS)

    Lockwood, A.; Ewell, R.; Wood, C.

    1981-01-01

    Preliminary results from a spacecraft system study show that an optimum hot junction temperature is in the range of 1500 K for advanced nuclear reactor technology combined with thermoelectric conversion. Advanced silicon germanium thermoelectric conversion is feasible if hot junction temperatures can be raised roughly 100 C or if gallium phosphide can be used to improve the figure of merit, but the performance is marginal. Two new classes of refractory materials, rare earth sulfides and boron-carbon alloys, are being investigated to improve the specific weight of the generator system. Preliminary data on the sulfides have shown very high figures of merit over short temperature ranges. Both n- and p-type doping have been obtained. Pure boron-carbide may extrapolate to high figure of merit at temperatures well above 1500 K but not lower temperature; n-type conduction has been reported by others, but not yet observed in the JPL program. Inadvertant impurity doping may explain the divergence of results reported.

  13. High temperature superconductors applications in telecommunications

    NASA Technical Reports Server (NTRS)

    Kumar, A. Anil; Li, Jiang; Zhang, Ming Fang

    1995-01-01

    The purpose of this paper is twofold: (1) to discuss high temperature superconductors with specific reference to their employment in telecommunications applications; and (2) to discuss a few of the limitations of the normally employed two-fluid model. While the debate on the actual usage of high temperature superconductors in the design of electronic and telecommunications devices - obvious advantages versus practical difficulties - needs to be settled in the near future, it is of great interest to investigate the parameters and the assumptions that will be employed in such designs. This paper deals with the issue of providing the microwave design engineer with performance data for such superconducting waveguides. The values of conductivity and surface resistance, which are the primary determining factors of a waveguide performance, are computed based on the two-fluid model. A comparison between two models - a theoretical one in terms of microscopic parameters (termed Model A) and an experimental fit in terms of macroscopic parameters (termed Model B) - shows the limitations and the resulting ambiguities of the two-fluid model at high frequencies and at temperatures close to the transition temperature. The validity of the two-fluid model is then discussed. Our preliminary results show that the electrical transport description in the normal and superconducting phases as they are formulated in the two-fluid model needs to be modified to incorporate the new and special features of high temperature superconductors. Parameters describing the waveguide performance - conductivity, surface resistance and attenuation constant - will be computed. Potential applications in communications networks and large scale integrated circuits will be discussed. Some of the ongoing work will be reported. In particular, a brief proposal is made to investigate of the effects of electromagnetic interference and the concomitant notion of electromagnetic compatibility (EMI/EMC) of high T

  14. High temperature superconductors applications in telecommunications

    SciTech Connect

    Kumar, A.A.; Li, J.; Zhang, M.F.

    1994-12-31

    The purpose of this paper is twofold: to discuss high temperature superconductors with specific reference to their employment in telecommunications applications; and to discuss a few of the limitations of the normally employed two-fluid model. While the debate on the actual usage of high temperature superconductors in the design of electronic and telecommunications devices-obvious advantages versus practical difficulties-needs to be settled in the near future, it is of great interest to investigate the parameters and the assumptions that will be employed in such designs. This paper deals with the issue of providing the microwave design engineer with performance data for such superconducting waveguides. The values of conductivity and surface resistance, which are the primary determining factors of a waveguide performance, are computed based on the two-fluid model. A comparison between two models-a theoretical one in terms of microscopic parameters (termed Model A) and an experimental fit in terms of macroscopic parameters (termed Model B)-shows the limitations and the resulting ambiguities of the two-fluid model at high frequencies and at temperatures close to the transition temperature. The validity of the two-fluid model is then discussed. Our preliminary results show that the electrical transport description in the normal and superconducting phases as they are formulated in the two-fluid model needs to be modified to incorporate the new and special features of high temperature superconductors. Parameters describing the waveguide performance-conductivity, surface resistance and attenuation constant-will be computed. Potential applications in communications networks and large scale integrated circuits will be discussed. Some of the ongoing work will be reported. In particular, a brief proposal is made to investigate of the effects of electromagnetic interference and the concomitant notion of electromagnetic compatibility (EMI/EMC) of high T{sub c} superconductors.

  15. Brine Sampling and Evaluation Program, 1990 report

    SciTech Connect

    Deal, D.E.; Abitz, R.J.; Myers, J.; Case, J.B.; Martin, M.L.; Roggenthen, W.M.; Belski, D.S.

    1991-08-01

    The data presented in this report are the result of Brine Sampling and Evaluation Program (BSEP) activities at the Waste Isolation Pilot Plant (WIPP) during 1990. When excavations began in 1982, small brine seepages (weeps) were observed on the walls. These brine occurrences were initially described as part of the Site Validation Program. Brine studies were formalized in 1985. The BSEP activities document and investigate the origins, hydraulic characteristics, extent, and composition of brine occurrences in the Permian Salado Formation and seepage of that brine into the excavations at the WIPP. The brine chemistry is important because it assists in understanding the origin of the brine and because it may affect possible chemical reactions in the buried waste after sealing the repository. The volume of brine and the hydrologic system that drives the brine seepage also need to be understood to assess the long-term performance of the repository. After more than eight years of observations (1982--1990), no credible evidence exists to indicate that enough naturally occurring brine will seep into the WIPP excavations to be of practical concern. The detailed observations and analyses summarized herein and in previous BSEP reports confirm the evidence apparent during casual visits to the underground workings -- that the excavations are remarkably dry.

  16. Mobility of elements during K-metasomatism of volcanic rocks by alkaline, saline brines

    SciTech Connect

    Chapin, C.E. )

    1992-01-01

    Silicic ignimbrites and interbedded mafic lavas of Oligocene age were altered by alkaline, saline brines in the Popotosa basin of the Rio Grande rift near Socorro, New Mexico. Alteration was toward a fine-grained assemblage of adularia + hematite [+-] quartz irrespective of initial rock composition. Elevated [delta][sup 18]O and the occurrence of zeolites, gypsum, and salt casts in overlying play a deposits indicates that the altering fluids were basin brines. Preliminary analysis of secondary inclusions in fractured quartz phenocrysts indicates temperatures near 100 C and salinities near 20 wt. % NaCl equivalent. To test element mobility, pairs of fresh and altered samples from each of 7 ignimbrite units plus 4 samples of interbedded mafic lavas were analyzed by XRF, INAA, and AA. The elements showing the greatest mobility during alteration of ignimbrites are listed below along with their enrichment factors (altered rock/fresh rock). Ignimbrites: enriched--K[sub 2]O 1.99, Rb 1.89, Ba 1.43, As 12.14, Sb 18.30, Pb 1.23; depleted--Na[sub 2]O 0.25, MgO 0.57, CaO 0.27, MnO 0.50, P[sub 2]O[sub 5] 0.75, Sr 0.54, Li 0.57, U 0.78, Br 0.67, Cu 0.90, Zn 0.69. The dramatic enrichment of As and Sb in both ignimbrites and mafic lavas indicates that these elements are highly mobile in oxidizing basin brine systems. K-metasomatism is a common type of alteration in rift basins, detachment terranes, aquifers through which brines have migrated.

  17. Brines in Crustal Processes: Important Roles Inferred From Experimental Studies (Invited)

    NASA Astrophysics Data System (ADS)

    Newton, R. C.; Manning, C. E.

    2009-12-01

    Concentrated salt solutions are increasingly implicated as active agents in many fluid-mediated deep- and mid-crust processes, including rock-melting, charnockitic alteration, trace-element depletion and enrichment, regional metasomatism including dehydration and rehydration, albitization, deep-crustal oxidation, and formation of economic mineral deposits. Unique properties of saline aqueous fluids at high P and T, recently revealed by experimental work, provide new explanations for these metasomatic features and encourage further search for a brine connection in other outstanding problems of metamorphism. Specific properties of high P-T NaCl solutions favorable for deep-crustal metasomatism are high solubility for some rock-forming components, especially CaO and FeO, even at high salt concentration, very low H2O activity as a consequence of pressure-induced dissociation, allowing compatibility with anhydrous (granulite facies) mineral assemblages, and high ability to infiltrate mineral grain boundaries. The high affinity of alkali chloride brines for CaO can explain trace element mobility in high grade metamorphism, by virtue of the high solubility of apatite, and the puzzling phenomenon of subsolidus charnockitic alteration, as in South India, in which orthopyroxene is formed from the incongruent dissolution of calcic amphibole. The great pressure effect on lowering H2O activity in concentrated pore-fluid brines causes fluid-present melting points of crustal rocks to swerve sharply to higher temperatures with increasing depth, in contrast to the behavior in the presence of pure H2O. This fact could account for the formation of swarms of granite intrusions in shear-zone-related settings, such as the Caledonide granites of Scotland and northern Ireland. It is postulated that salty solutions of deep-seated origin inhibit melting as they rise through the lower crust, but induce large-scale melting at mid-crust levels because of increase of H2O activity by release of

  18. Operator manual: High temperature heat pump

    NASA Astrophysics Data System (ADS)

    Dyer, D. F.; Maples, G.; Burch, T. E.; Chancellor, P. D.

    1980-03-01

    Experimental data were obtained from operating a high temperature heat pump system. The use of methanol as a working fluid necessitated careful monitoring of refrigerant temperatures and pressures with chemical analysis performed on the working fluid during scheduled down time. Materials sent to vendors and quotes received concerning equipment (compressor, evaporator, condensor, air heater, dryer, two accumulator tanks, and three expansion valves) are discussed. The detailed design and pricing estimates are included. Additional information on layout and construction; start-up; testing; shut down; scheduled maintenance and inspection; safety precautions; control system; and trouble shooting is presented.

  19. Coal transformation under high-temperature catagenesis

    SciTech Connect

    Melenevsky, V.N.; Sokol, E.V.; Fomin, A.N.

    2006-07-01

    In this paper we consider products of natural pyrolysis of lignite, which resulted from the high-temperature spontaneous combustion of spoil heaps of the Chelyabinsk coal basin. These products were studied by pyrolysis, element and petrographic analyses, chromatomass spectrometry, and X-ray diffraction method. We have established that under reducing conditions, the degree of pyrogenic coal transformation and the composition of pyrolysis products vary greatly, from graphite-like phases to bitumens, and depend on the temperature and degree of the system openness.

  20. Fiber specklegram sensors sensitivities at high temperatures

    NASA Astrophysics Data System (ADS)

    Rodriguez-Cobo, L.; Lomer, M.; Lopez-Higuera, J. M.

    2015-09-01

    In this work, the sensitivity of Fiber Specklegram Sensors to high temperatures (up to 800ºC) have been studied. Two multimode silica fibers have been introduced into a tubular furnace while a HeNe laser source was launched into a fiber edge, projecting speckle patterns to a commercial webcam. A computer generated different heating and cooling sweeps while the specklegram evolution was recorded. The achieved results exhibit a remarkably linearity in FSS's sensitivity for temperatures under 800ºC, following the thermal expansion of fused silica.

  1. High-Temperature Behavior of Cellulose I

    SciTech Connect

    Matthews, James F.; Bergenstråhle, Malin; Beckham, Gregg T.; Himmel, Michael E.; Nimlos, Mark R.; Brady, John W.; Crowley, Michael F.

    2011-03-17

    We use molecular simulation to elucidate the structural behavior of small hydrated cellulose Iβ microfibrils heated to 227 °C (500 K) with two carbohydrate force fields. In contrast to the characteristic two-dimensional hydrogen-bonded layer sheets present in the cellulose Iβ crystal structure, we show that at high temperature a three-dimensional hydrogen bond network forms, made possible by hydroxymethyl groups changing conformation from trans–gauche (TG) to gauche–gauche (GG) in every second layer corresponding to “center” chains in cellulose Iβ and from TG to gauche–trans (GT) in the “origin” layer. The presence of a regular three-dimensional hydrogen bond network between neighboring sheets eliminates the possibility of twist, whereas two-dimensional hydrogen bonding allows for microfibril twist to occur. Structural features of this high-temperature phase as determined by molecular simulation may explain several experimental observations for which no detailed structural basis has been offered. This includes an explanation for the observed temperature and crystal size dependence for the extent of hydrogen/deuterium exchange, and diffraction patterns of cellulose at high temperature.

  2. The moon as a high temperature condensate

    NASA Technical Reports Server (NTRS)

    Anderson, D. L.

    1972-01-01

    The accretion during condensation mechanism is used to explain the differences in composition of the terrestrial planets and the moon. Many of the properties of the moon, including the enrichment in Ca, Al, Ti, U, Th, Ba, Sr and the REE and the depletion in Fe, Rb, K, Na and other volatiles can be understood if the moon represents a high temperature condensate from the solar nebula. Thermodynamic calculations show that Ca, Al and Ti rich compounds condense first in a cooling nebula. The high temperature mineralogy is gehlenite, spinel perovskite, Ca-Al-rich pyroxenes and anorthite. The model is consistent with extensive early melting, shallow melting at 3 A.E. and with presently high speed internal temperatures. It is predicted that the outer 250 km is rich in plagioclase and FeO. The low iron content of the interior in this model raises the interior temperatures estimated from electrical conductivity by some 800 C. The lunar crust is 80 percent gabbroic anorthosite, 20 percent basalt and is about 250-270 km thick. The lunar mantle is probably composed of spinel, merwinite and diopside with a density of 3.4 g/cu cm.

  3. High temperature dynamic engine seal technology development

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Dellacorte, Christopher; Machinchick, Michael; Mutharasan, Rajakkannu; Du, Guang-Wu; Ko, Frank; Sirocky, Paul J.; Miller, Jeffrey H.

    1992-01-01

    Combined cycle ramjet/scramjet engines being designed for advanced hypersonic vehicles, including the National Aerospace Plane (NASP), require innovative high temperature dynamic seals to seal the sliding interfaces of the articulated engine panels. New seals are required that will operate hot (1200 to 2000 F), seal pressures ranging from 0 to 100 psi, remain flexible to accommodate significant sidewall distortions, and resist abrasion over the engine's operational life. This report reviews the recent high temperature durability screening assessments of a new braided rope seal concept, braided of emerging high temperature materials, that shows promise of meeting many of the seal demands of hypersonic engines. The paper presents durability data for: (1) the fundamental seal building blocks, a range of candidate ceramic fiber tows; and for (2) braided rope seal subelements scrubbed under engine simulated sliding, temperature, and preload conditions. Seal material/architecture attributes and limitations are identified through the investigations performed. The paper summarizes the current seal technology development status and presents areas in which future work will be performed.

  4. Lightweight high-temperature fuel metering valves

    NASA Astrophysics Data System (ADS)

    Bennett, Joe

    AlliedSignal Fluid systems has provided fuel metering valve hardware to three aircraft engine manufacturers for evaluation. Two of the progams were Integrated High Performance Turbine Engine Technology (IHPTET) related. The third program was an IR&D effort. Bench tests and evaluation of all three valve designs have been completed, and one of the designs has actually been used for engine test. Engine testing of the other two valve designs is planned for the future. These three designs are similar, but each is intended to be usused in different system configurations, and each valve design offers unique features. The design approaches used for the three valve designs incorporate several new and innovative technologies, including high-temperature brushless dc motor actuators, low-pressure loss metering element design, fiber optic rotarty output position sensor, no-moving-parts oscillating jet flow meter, high-temperature RS (rapid solidification) aluminum alloy, high-temperature elastomeric seals, high-pressure shutoff capabilities, and closed loop electronic fuel flow metering.

  5. High temperature aircraft research furnace facilities

    NASA Technical Reports Server (NTRS)

    Smith, James E., Jr.; Cashon, John L.

    1992-01-01

    Focus is on the design, fabrication, and development of the High Temperature Aircraft Research Furnace Facilities (HTARFF). The HTARFF was developed to process electrically conductive materials with high melting points in a low gravity environment. The basic principle of operation is to accurately translate a high temperature arc-plasma gas front as it orbits around a cylindrical sample, thereby making it possible to precisely traverse the entire surface of a sample. The furnace utilizes the gas-tungsten-arc-welding (GTAW) process, also commonly referred to as Tungsten-Inert-Gas (TIG). The HTARFF was developed to further research efforts in the areas of directional solidification, float-zone processing, welding in a low-gravity environment, and segregation effects in metals. The furnace is intended for use aboard the NASA-JSC Reduced Gravity Program KC-135A Aircraft.

  6. High-Temperature Graphite/Phenolic Composite

    NASA Technical Reports Server (NTRS)

    Seal, Ellis C.; Bodepudi, Venu P.; Biggs, Robert W., Jr.; Cranston, John A.

    1995-01-01

    Graphite-fiber/phenolic-resin composite material retains relatively high strength and modulus of elasticity at temperatures as high as 1,000 degrees F. Costs only 5 to 20 percent as much as refractory materials. Fabrication composite includes curing process in which application of full autoclave pressure delayed until after phenolic resin gels. Curing process allows moisture to escape, so when composite subsequently heated in service, much less expansion of absorbed moisture and much less tendency toward delamination. Developed for nose cone of external fuel tank of Space Shuttle. Other potential aerospace applications for material include leading edges, parts of nozzles, parts of aircraft engines, and heat shields. Terrestrial and aerospace applications include structural firewalls and secondary structures in aircraft, spacecraft, and ships. Modified curing process adapted to composites of phenolic with other fiber reinforcements like glass or quartz. Useful as high-temperature circuit boards and electrical insulators.

  7. The metallurgy of high temperature alloys

    NASA Technical Reports Server (NTRS)

    Tien, J. K.; Purushothaman, S.

    1976-01-01

    Nickel-base, cobalt-base, and high nickel and chromium iron-base alloys are dissected, and their microstructural and chemical components are assessed with respect to the various functions expected of high temperature structural materials. These functions include the maintenance of mechanical integrity over the strain-rate spectrum from creep resistance through fatigue crack growth resistance, and such alloy stability expectations as microstructural coarsening resistance, phase instability resistance and oxidation and corrosion resistance. Special attention will be given to the perennial conflict and trade-off between strength, ductility and corrosion and oxidation resistance. The newest developments in the constitution of high temperature alloys will also be discussed, including aspects relating to materials conservation.

  8. Optically transparent high temperature shape memory polymers.

    PubMed

    Xiao, Xinli; Qiu, Xueying; Kong, Deyan; Zhang, Wenbo; Liu, Yanju; Leng, Jinsong

    2016-03-21

    Optically transparent shape memory polymers (SMPs) have potential in advanced optoelectronic and other common shape memory applications, and here optically transparent shape memory polyimide is reported for the first time. The polyimide possesses a glass transition temperature (Tg) of 171 °C, higher than the Tg of other transparent SMPs reported, and the influence of molecular structure on Tg is discussed. The 120 μm thick polyimide film exhibits transmittance higher than 81% in 450-800 nm, and the possible mechanism of its high transparency is analyzed, which will benefit further research on other transparent high temperature SMPs. The transparent polyimide showed excellent thermomechanical properties and shape memory performances, and retained high optical transparency after many shape memory cycles. PMID:26686222

  9. Metamorphosed Plio-Pleistocene evaporites and the origins of hypersaline brines in the Salton Sea geothermal system, California: Fluid inclusion evidence

    SciTech Connect

    McKibben, M.A.; Williams, A.E.; Okubo, Susumu )

    1988-05-01

    The Salton Sea geothermal system (SSGS) occurs in Plio-Pleistocene deltaic-lacustrine-evaporite sediments deposited in the Salton Trough, an active continental rift zone. Temperatures up to 365{degree}C and hypersaline brines with up to 26 wt.% TDS are encountered at 1-3 km depth in the sediments, which are undergoing active greenschist facies hydrothermal metamorphism. Previous models for the origins of the Na-Ca-K-Cl brines have assumed that the high salinities were derived mainly from the downward percolation of cold, dense brines formed by low-temperature dissolution of shallow non-marine evaporites. New drillcores from the central part of the geothermal field contain metamorphosed, bedded evaporites at 1 km depth consisting largely of hornfelsic anhydrite interbedded with anhydrite-cemented solution-collapse shale breccias. Fluid inclusions trapped within the bedded and breccia-cementing anhydrite homogenize at 300{degree}C and contain saline Na-Ca-K-Cl brines. Some of the inclusions contain up to 50 vol.% halite, sylvite and carbonate crystals at room temperature, and some halite crystals persist to above 300{degree}C upon laboratory heating. The data are consistent with the trapping of halite-saturated Na-Ca-K-Cl fluids during hydrothermal metamorphism of the evaporites and accompanying solution collapse of interbedded shales. The authors conclude that many of the slat crystals in inclusions are the residuum of bedded evaporitic salt that was dissolved during metamorphism by heated connate fluids.

  10. High Temperature Fluoride Salt Test Loop

    SciTech Connect

    Aaron, Adam M.; Cunningham, Richard Burns; Fugate, David L.; Holcomb, David Eugene; Kisner, Roger A.; Peretz, Fred J.; Robb, Kevin R.; Wilson, Dane F.; Yoder, Jr, Graydon L.

    2015-12-01

    Effective high-temperature thermal energy exchange and delivery at temperatures over 600°C has the potential of significant impact by reducing both the capital and operating cost of energy conversion and transport systems. It is one of the key technologies necessary for efficient hydrogen production and could potentially enhance efficiencies of high-temperature solar systems. Today, there are no standard commercially available high-performance heat transfer fluids above 600°C. High pressures associated with water and gaseous coolants (such as helium) at elevated temperatures impose limiting design conditions for the materials in most energy systems. Liquid salts offer high-temperature capabilities at low vapor pressures, good heat transport properties, and reasonable costs and are therefore leading candidate fluids for next-generation energy production. Liquid-fluoride-salt-cooled, graphite-moderated reactors, referred to as Fluoride Salt Reactors (FHRs), are specifically designed to exploit the excellent heat transfer properties of liquid fluoride salts while maximizing their thermal efficiency and minimizing cost. The FHR s outstanding heat transfer properties, combined with its fully passive safety, make this reactor the most technologically desirable nuclear power reactor class for next-generation energy production. Multiple FHR designs are presently being considered. These range from the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) [1] design originally developed by UC-Berkeley to the Small Advanced High-Temperature Reactor (SmAHTR) and the large scale FHR both being developed at ORNL [2]. The value of high-temperature, molten-salt-cooled reactors is also recognized internationally, and Czechoslovakia, France, India, and China all have salt-cooled reactor development under way. The liquid salt experiment presently being developed uses the PB-AHTR as its focus. One core design of the PB-AHTR features multiple 20 cm diameter, 3.2 m long fuel channels

  11. Gasification of high ash, high ash fusion temperature bituminous coals

    DOEpatents

    Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

    2015-11-13

    This invention relates to gasification of high ash bituminous coals that have high ash fusion temperatures. The ash content can be in 15 to 45 weight percent range and ash fusion temperatures can be in 1150.degree. C. to 1500.degree. C. range as well as in excess of 1500.degree. C. In a preferred embodiment, such coals are dealt with a two stage gasification process--a relatively low temperature primary gasification step in a circulating fluidized bed transport gasifier followed by a high temperature partial oxidation step of residual char carbon and small quantities of tar. The system to process such coals further includes an internally circulating fluidized bed to effectively cool the high temperature syngas with the aid of an inert media and without the syngas contacting the heat transfer surfaces. A cyclone downstream of the syngas cooler, operating at relatively low temperatures, effectively reduces loading to a dust filtration unit. Nearly dust- and tar-free syngas for chemicals production or power generation and with over 90%, and preferably over about 98%, overall carbon conversion can be achieved with the preferred process, apparatus and methods outlined in this invention.

  12. Hydrographic changes during 20 years in the brine-filled basins of the Red Sea

    NASA Astrophysics Data System (ADS)

    Anschutz, Pierre; Blanc, Gérard; Chatin, Fabienne; Geiller, Magali; Pierret, Marie-Claire

    1999-10-01

    Many of the deep basins filled by hot brines in the Red Sea have not been investigated since their discovery in the early 1970s. Twenty years later, in September 1992, six of these deeps were revisited. The temperature and salinity of the Suakin, Port Sudan, Chain B, and Nereus deeps ranged from 23.25 to 44.60°C and from 144 to 270‰. These values were approximately the same in 1972, indicating that the budget of heat and salt was quite balanced. We measured strong gradients of properties in the transition zone between brines and overlying seawater. The contribution of salinity to the density gradient was more than one order of magnitude higher than the opposite contribution of temperature across the seawater-brine interface. Therefore the interface was extemely stable, and the transfer of properties across it was considered to be controlled mostly by molecular diffusion. We calculate that the diffusional transport of salt from the brines to seawater cannot affect significantly the salinity of the brines over a 20 year period, which agrees with the observations. The brine pools can persist for centuries with no salt input. Therefore, the persisence of brines does not correspond to a steady balance between diffusional loss and continuous input of hydrothermal solutions. Deeps that experience only episodical hydrothermal brine supplies may persist for a long time with salt inherited from past inputs. The theoretical loss of heat by diffusion from the brine to seawater was higher than the observed decrease in temperature of the brine pool during the 20 year period of observation. We calculated that the heat flux out of the pools into the overlying seawater was compensated by a heat flux into the pools of about 250-600 mW/m 2. This range of values corresponds to bottom heat flow values that have been reported earlier for the axial zone of the Red Sea. In contrast to the other brine pools, the temperature and salinity of the Valdivia Deep brine increased by 4.1°C and

  13. Strain sensing technology for high temperature applications

    NASA Technical Reports Server (NTRS)

    Williams, W. Dan

    1993-01-01

    This review discusses the status of strain sensing technology for high temperature applications. Technologies covered are those supported by NASA such as required for applications in hypersonic vehicles and engines, advanced subsonic engines, as well as material and structure development. The applications may be at temperatures of 540 C (1000 F) to temperatures in excess of 1400 C (2500 F). The most promising technologies at present are the resistance strain gage and remote sensing schemes. Resistance strain gages discussed include the BCL gage, the LaRC compensated gage, and the PdCr gage. Remote sensing schemes such as laser based speckle strain measurement, phase-shifling interferometry, and x-ray extensometry are discussed. Present status and limitations of these technologies are presented.

  14. Improved high-temperature resistant matrix resins

    NASA Technical Reports Server (NTRS)

    Green, H. E.; Chang, G. E.; Wright, W. F.; Ueda, K.; Orell, M. K.

    1989-01-01

    A study was performed with the objective of developing matrix resins that exhibit improved thermo-oxidative stability over state-of-the-art high temperature resins for use at temperatures up to 644 K (700 F) and air pressures up to 0.7 MPa (100 psia). The work was based upon a TRW discovered family of polyimides currently licensed to and marketed by Ethyl Corporation as EYMYD(R) resins. The approach investigated to provide improved thermo-oxidative properties was to use halogenated derivatives of the diamine, 2, 2-bis (4-(4-aminophenoxy)phenyl) hexafluoropropane (4-BDAF). Polyimide neat resins and Celion(R) 12,000 composites prepared from fluorine substituted 4-BDAF demonstrated unexpectedly lower glass transition temperatures (Tg) and thermo-oxidative stabilities than the baseline 4-BDAF/PMDA polymer.

  15. Compliant high temperature seals for dissimilar materials

    DOEpatents

    Rynders, Steven Walton; Minford, Eric; Tressler, Richard Ernest; Taylor, Dale M.

    2001-01-01

    A high temperature, gas-tight seal is formed by utilizing one or more compliant metallic toroidal ring sealing elements, where the applied pressure serves to activate the seal, thus improving the quality of the seal. The compliant nature of the sealing element compensates for differences in thermal expansion between the materials to be sealed, and is particularly useful in sealing a metallic member and a ceramic tube art elevated temperatures. The performance of the seal may be improved by coating the sealing element with a soft or flowable coating such as silver or gold and/or by backing the sealing element with a bed of fine powder. The material of the sealing element is chosen such that the element responds to stress elastically, even at elevated temperatures, permitting the seal to operate through multiple thermal cycles.

  16. Thermoelectric properties by high temperature annealing

    NASA Technical Reports Server (NTRS)

    Ren, Zhifeng (Inventor); Chen, Gang (Inventor); Kumar, Shankar (Inventor); Lee, Hohyun (Inventor)

    2009-01-01

    The present invention generally provides methods of improving thermoelectric properties of alloys by subjecting them to one or more high temperature annealing steps, performed at temperatures at which the alloys exhibit a mixed solid/liquid phase, followed by cooling steps. For example, in one aspect, such a method of the invention can include subjecting an alloy sample to a temperature that is sufficiently elevated to cause partial melting of at least some of the grains. The sample can then be cooled so as to solidify the melted grain portions such that each solidified grain portion exhibits an average chemical composition, characterized by a relative concentration of elements forming the alloy, that is different than that of the remainder of the grain.

  17. Opacification of high temperature fibrous insulation

    NASA Technical Reports Server (NTRS)

    Miller, W. C.; Collins, J. O.

    1984-01-01

    A study was conducted to determine the merits of adding particulate materials to silica fiber felts to increase their resistance to the passage of thermal radiation. Laboratory samples containing 5, 10, and 15 percent of chromium oxide, silicon carbide, and titanium dioxide were prepared and evaluated in accordance with ASTM C-518 thermal conductivity test method at 425 C (800 F) mean temperature. The titania particles averaging 3-4 micrometers in diameter were found to be the most effective. This was followed by a short plant run, in order to confirm the initial results on the laboratory samples. These samples were tested according to ASTM C-201 High Temperature Calorimeter from 93 C to 760 C (200 F to 1400 F) mean temperature. The ten percent by weight of titania resulted in an optimum effectiveness, and reduced the conductivity over 20% at 760 C (1400 F).

  18. Simulated Data for High Temperature Composite Design

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.; Abumeri, Galib H.

    2006-01-01

    The paper describes an effective formal method that can be used to simulate design properties for composites that is inclusive of all the effects that influence those properties. This effective simulation method is integrated computer codes that include composite micromechanics, composite macromechanics, laminate theory, structural analysis, and multi-factor interaction model. Demonstration of the method includes sample examples for static, thermal, and fracture reliability for a unidirectional metal matrix composite as well as rupture strength and fatigue strength for a high temperature super alloy. Typical results obtained for a unidirectional composite show that the thermal properties are more sensitive to internal local damage, the longitudinal properties degrade slowly with temperature, the transverse and shear properties degrade rapidly with temperature as do rupture strength and fatigue strength for super alloys.

  19. High temperature application of retrievable MWD systems

    SciTech Connect

    Coe, R.; Saito, S.

    1995-12-31

    MWD systems are currently used to monitor the direction of wellbores. MWD systems with higher temperature capabilities are required to meet the needs of deep and geothermal drilling. A technique has been developed for geothermal drilling that allows a fully retrievable MWD system to be used in wells with formation temperatures in excess of 350{degrees}C. This operational technique involves use of the MWD system in combination with operational procedures adapted to cope with the need for continuous directional control while drilling. Descriptions of the drilling environment are given in areas of Japan where high temperature drilling is performed. Possible future requirements are reviewed. The MWD system is described giving current technical specifications and capabilities. The operational method for utilizing the MWD is detailed. A summary of successful applications is discussed and specific case studies given. The efficiency of using the technique is reviewed.

  20. High Temperature Superconductivity and Cold Fusion

    NASA Astrophysics Data System (ADS)

    Rabinowitz, Mario

    There are numerous historical and scientific parallels between high temperature superconductivity (HTSC) and the newly emerging field of cold fusion (CF). Just as the charge carrier effective mass plays an important role in SC, the deuteron effective mass may play a vital role in CF. A new theory including effects of proximity, electron shielding, and decreased effective mass of the fusing nuclei can account for the reported CF results. A quantum-gas model that covers the range from low temperature to superhigh temperature SC indicates an increased Tc with reduced dimensionality. A reduced dimensionality effect may also enhance CF. A relation is shown between CF and the significant cluster-impact fusion experiments.

  1. High refractive index and temperature sensitivity LPGs for high temperature operation

    NASA Astrophysics Data System (ADS)

    Nascimento, I. M.; Gouveia, C.; Jana, Surnimal; Bera, Susanta; Baptista, J. M.; Moreira, Paulo; Biwas, Palas; Bandyopadhyay, Somnath; Jorge, Pedro A. S.

    2013-11-01

    A fiber optic sensor for high sensitivity refractive index and temperature measurement able to withstand temperature up to 450 °C is reported. Two identical LPG gratings were fabricated, whereas one was coated with a high refractive index (~1.78) sol-gel thin film in order to increase its sensitivity to the external refractive index. The two sensors were characterized and compared in refractive index and temperature. Sensitivities of 1063 nm/RIU (1.338 - 1.348) and 260 pm/°C were achieved for refractive index and temperature, respectively.

  2. High-temperature metal-organic magnets.

    PubMed

    Jain, Rajsapan; Kabir, Khayrul; Gilroy, Joe B; Mitchell, Keith A R; Wong, Kin-chung; Hicks, Robin G

    2007-01-18

    For over two decades there have been intense efforts aimed at the development of alternatives to conventional magnets, particularly materials comprised in part or wholly of molecular components. Such alternatives offer the prospect of realizing magnets fabricated through controlled, low-temperature, solution-based chemistry, as opposed to high-temperature metallurgical routes, and also the possibility of tuning magnetic properties through synthesis. However, examples of magnetically ordered molecular materials at or near room temperature are extremely rare, and the properties of these materials are often capricious and difficult to reproduce. Here we present a versatile solution-based route to a new class of metal-organic materials exhibiting magnetic order well above room temperature. Reactions of the metal (M) precursor complex bis(1,5-cyclooctadiene)nickel with three different organics A-TCNE (tetracyanoethylene), TCNQ (7,7,8,8-tetracyanoquinodimethane) or DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone)--proceed via electron transfer from nickel to A and lead to materials containing Ni(II) ions and reduced forms of A in a 2:1 Ni:A ratio--that is, opposite to that of conventional (low Curie temperature) MA(2)-type magnets. These materials also contain oxygen-based species within their architectures. Magnetic characterization of the three compounds reveals spontaneous field-dependent magnetization and hysteresis at room temperature, with ordering temperatures well above ambient. The unusual stoichiometry and striking magnetic properties highlight these three compounds as members of a class of stable magnets that are at the interface between conventional inorganic magnets and genuine molecule-based magnets.

  3. Plasma synthesis of high temperature ceramic films

    SciTech Connect

    Brown, I.G.; Monteiro, O.R.

    1998-11-01

    Thin films of alumina, chromia, mullite, yttria and zirconia have been synthesized using a plasma-based method called metal plasma immersion ion implantation and deposition (Mepiiid)--a highly versatile plasma deposition technique with ion energy control. Monolithic films (a single ceramic component) and multilayer films (individual layers of different ceramic materials) were formed. The films were characterized for their composition and structure in a number of different ways, and the high temperature performance of the films was explored, particularly for their ability to maintain their integrity and adhesion when subjected to repetitive high temperature thermal cycling up 1100 C. We found that the films retain their adhesion and quality without any apparent degradation with time, even after a large number of cycles; (the tests were extended out to a total of 40 cycles each of 24 hours duration). After repetitive high temperature thermal cycling, the film-substrate adhesion was greater than {approx}70 Mpa, the instrumental limit of measurement, and the interface toughness was approximately 0.8 MPa m{sup 1/2}.

  4. Electrochemical high-temperature gas sensors

    NASA Astrophysics Data System (ADS)

    Saruhan, B.; Stranzenbach, M.; Yüce, A.; Gönüllü, Y.

    2012-06-01

    Combustion produced common air pollutant, NOx associates with greenhouse effects. Its high temperature detection is essential for protection of nature. Component-integration capable high-temperature sensors enable the control of combustion products. The requirements are quantitative detection of total NOx and high selectivity at temperatures above 500°C. This study reports various approaches to detect NO and NO2 selectively under lean and humid conditions at temperatures from 300°C to 800°C. All tested electrochemical sensors were fabricated in planar design to enable componentintegration. We suggest first an impedance-metric gas sensor for total NOx-detection consisting of NiO- or NiCr2O4-SE and PYSZ-electrolyte. The electrolyte-layer is about 200μm thickness and constructed of quasi-single crystalline columns. The sensing-electrode (SE) is magnetron sputtered thin-layers of NiO or NiCr2O4. Sensor sensitivity for detection of total NOx has been measured by applying impedance analysis. The cross-sensitivity to other emission gases such as CO, CO2, CH4 and oxygen (5 vol.%) has been determined under 0-1000ppm NO. Sensor maintains its high sensitivity at temperatures up to 550°C and 600°C, depending on the sensing-electrode. NiO-SE yields better selectivity to NO in the presence of oxygen and have shorter response times comparing to NiCr2O4-SE. For higher temperature NO2-sensing capability, a resistive DC-sensor having Al-doped TiO2-sensing layers has been employed. Sensor-sensitivity towards NO2 and cross-sensitivity to CO has been determined in the presence of H2O at temperatures 600°C and 800°C. NO2 concentrations varying from 25 to 100ppm and CO concentrations from 25 to 75ppm can be detected. By nano-tubular structuring of TiO2, NO2 sensitivity of the sensor was increased.

  5. High-Temperature Piezoelectric Ceramic Developed

    NASA Technical Reports Server (NTRS)

    Sayir, Ali; Farmer, Serene C.; Dynys, Frederick W.

    2005-01-01

    Active combustion control of spatial and temporal variations in the local fuel-to-air ratio is of considerable interest for suppressing combustion instabilities in lean gas turbine combustors and, thereby, achieving lower NOx levels. The actuator for fuel modulation in gas turbine combustors must meet several requirements: (1) bandwidth capability of 1000 Hz, (2) operating temperature compatible with the fuel temperature, which is in the vicinity of 400 F, (3) stroke of approximately 4 mils (100 m), and (4) force of 300 lb-force. Piezoelectric actuators offer the fastest response time (microsecond time constants) and can generate forces in excess of 2000 lb-force. The state-of-the-art piezoceramic material in industry today is Pb(Zr,Ti)O3, called PZT. This class of piezoelectric ceramic is currently used in diesel fuel injectors and in the development of high-response fuel modulation valves. PZT materials are generally limited to operating temperatures of 250 F, which is 150 F lower than the desired operating temperature for gas turbine combustor fuel-modulation injection valves. Thus, there is a clear need to increase the operating temperature range of piezoceramic devices for active combustion control in gas turbine engines.

  6. Nontrivial center dominance in high temperature QCD

    NASA Astrophysics Data System (ADS)

    Ishikawa, K.-I.; Iwasaki, Y.; Nakayama, Yu; Yoshie, T.

    2016-07-01

    We investigate the properties of quarks and gluons above the chiral phase transition temperature Tc, using the renormalization group (RG) improved gauge action and the Wilson quark action with two degenerate quarks mainly on a 323 × 16 lattice. In the one-loop perturbation theory, the thermal ensemble is dominated by the gauge configurations with effectively Z(3) center twisted boundary conditions, making the thermal expectation value of the spatial Polyakov loop take a nontrivial Z(3) center. This is in agreement with our lattice simulation of high temperature quantum chromodynamics (QCD). We further observe that the temporal propagator of massless quarks at extremely high temperature β = 100.0(T ≃ 1058T c) remarkably agrees with the temporal propagator of free quarks with the Z(3) twisted boundary condition for t/Lt ≥ 0.2, but differs from that with the Z(3) trivial boundary condition. As we increase the mass of quarks mq, we find that the thermal ensemble continues to be dominated by the Z(3) twisted gauge field configurations as long as mq ≤ 3.0T and above that the Z(3) trivial configurations come in. The transition is similar to what we found in the departure from the conformal region in the zero-temperature many-flavor conformal QCD on a finite lattice by increasing the mass of quarks.

  7. Evaluation of high temperature capacitor dielectrics

    NASA Technical Reports Server (NTRS)

    Hammoud, Ahmad N.; Myers, Ira T.

    1992-01-01

    Experiments were carried out to evaluate four candidate materials for high temperature capacitor dielectric applications. The materials investigated were polybenzimidazole polymer and three aramid papers: Voltex 450, Nomex 410, and Nomex M 418, an aramid paper containing 50 percent mica. The samples were heat treated for six hours at 60 C and the direct current and 60 Hz alternating current breakdown voltages of both dry and impregnated samples were obtained in a temperature range of 20 to 250 C. The samples were also characterized in terms of their dielectric constant, dielectric loss, and conductivity over this temperature range with an electrical stress of 60 Hz, 50 V/mil present. Additional measurements are underway to determine the volume resistivity, thermal shrinkage, and weight loss of the materials. Preliminary data indicate that the heat treatment of the films slightly improves the dielectric properties with no influence on their breakdown behavior. Impregnation of the samples leads to significant increases in both alternating and direct current breakdown strength. The results are discussed and conclusions made concerning their suitability as high temperature capacitor dielectrics.

  8. Medium Deep High Temperature Heat Storage

    NASA Astrophysics Data System (ADS)

    Bär, Kristian; Rühaak, Wolfram; Schulte, Daniel; Welsch, Bastian; Chauhan, Swarup; Homuth, Sebastian; Sass, Ingo

    2015-04-01

    Heating of buildings requires more than 25 % of the total end energy consumption in Germany. Shallow geothermal systems for indirect use as well as shallow geothermal heat storage systems like aquifer thermal energy storage (ATES) or borehole thermal energy storage (BTES) typically provide low exergy heat. The temperature levels and ranges typically require a coupling with heat pumps. By storing hot water from solar panels or thermal power stations with temperatures of up to 110 °C a medium deep high temperature heat storage (MDHTS) can be operated on relatively high temperature levels of more than 45 °C. Storage depths of 500 m to 1,500 m below surface avoid conflicts with groundwater use for drinking water or other purposes. Permeability is typically also decreasing with greater depth; especially in the crystalline basement therefore conduction becomes the dominant heat transport process. Solar-thermal charging of a MDHTS is a very beneficial option for supplying heat in urban and rural systems. Feasibility and design criteria of different system configurations (depth, distance and number of BHE) are discussed. One system is designed to store and supply heat (300 kW) for an office building. The required boreholes are located in granodioritic bedrock. Resulting from this setup several challenges have to be addressed. The drilling and completion has to be planned carefully under consideration of the geological and tectonical situation at the specific site.

  9. Noise temperature in graphene at high frequencies

    NASA Astrophysics Data System (ADS)

    Rengel, Raúl; Iglesias, José M.; Pascual, Elena; Martín, María J.

    2016-07-01

    A numerical method for obtaining the frequency-dependent noise temperature in monolayer graphene is presented. From the mobility and diffusion coefficient values provided by Monte Carlo simulation, the noise temperature in graphene is studied up to the THz range, considering also the influence of different substrate types. The influence of the applied electric field is investigated: the noise temperature is found to increase with the applied field, dropping down at high frequencies (in the sub-THz range). The results show that the low-frequency value of the noise temperature in graphene on a substrate tends to be reduced as compared to the case of suspended graphene due to the important effect of remote polar phonon interactions, thus indicating a reduced emitted noise power; however, at very high frequencies the influence of the substrate tends to be significantly reduced, and the differences between the suspended and on-substrate cases tend to be minimized. The values obtained are comparable to those observed in GaAs and semiconductor nitrides.

  10. Evaluation of high temperature capacitor dielectrics

    NASA Astrophysics Data System (ADS)

    Hammoud, Ahmad N.; Myers, Ira T.

    Experiments were carried out to evaluate four candidate materials for high temperature capacitor dielectric applications. The materials investigated were polybenzimidazole polymer and three aramid papers: Voltex 450, Nomex 410, and Nomex M 418, an aramid paper containing 50 percent mica. The samples were heat treated for six hours at 60 C and the direct current and 60 Hz alternating current breakdown voltages of both dry and impregnated samples were obtained in a temperature range of 20 to 250 C. The samples were also characterized in terms of their dielectric constant, dielectric loss, and conductivity over this temperature range with an electrical stress of 60 Hz, 50 V/mil present. Additional measurements are underway to determine the volume resistivity, thermal shrinkage, and weight loss of the materials. Preliminary data indicate that the heat treatment of the films slightly improves the dielectric properties with no influence on their breakdown behavior. Impregnation of the samples leads to significant increases in both alternating and direct current breakdown strength. The results are discussed and conclusions made concerning their suitability as high temperature capacitor dielectrics.

  11. High temperature furnace modeling and performance verifications

    NASA Technical Reports Server (NTRS)

    Smith, James E., Jr.

    1988-01-01

    Analytical, numerical and experimental studies were performed on two classes of high temperature materials processing furnaces. The research concentrates on a commercially available high temperature furnace using zirconia as the heating element and an arc furnace based on a ST International tube welder. The zirconia furnace was delivered and work is progressing on schedule. The work on the arc furnace was initially stalled due to the unavailability of the NASA prototype, which is actively being tested aboard the KC-135 experimental aircraft. A proposal was written and funded to purchase an additional arc welder to alleviate this problem. The ST International weld head and power supply were received and testing will begin in early November. The first 6 months of the grant are covered.

  12. Precision control of high temperature furnaces

    SciTech Connect

    Pollock, G.G.

    1994-12-31

    It is an object of the present invention to provide precision control of high temperature furnaces. It is another object of the present invention to combine the power of two power supplies of greatly differing output capacities in a single furnace. This invention combines two power supplies to control a furnace. A main power supply heats the furnace in the traditional manner, while the power from the auxiliary supply is introduced as a current flow through charged particles existing due to ionized gas or thermionic emission. The main power supply provides the bulk heating power and the auxiliary supply provides a precise and fast power source such that the precision of the total power delivered to the furnace is improved. Further, this invention comprises a means for high speed measurement of temperature of the process by the method of measuring the amount of current flow in a deliberately induced charged particle current.

  13. High temperature superconductors for magnetic suspension applications

    NASA Technical Reports Server (NTRS)

    Mcmichael, C. K.; Cooley, R. S.; Chen, Q. Y.; Ma, K. B.; Lamb, M. A.; Meng, R. L.; Chu, C. W.; Chu, W. K.

    1994-01-01

    High temperature superconductors (HTS) hold the promise for applications in magnetic levitation bearings, vibration damping, and torque coupling. Traditional magnetic suspension systems require active feedback and vibration controls in which power consumption and low frequency vibration are among the major engineering concerns. HTS materials have been demonstrated to be an enabling approach towards such problems due to their flux trapping properties. In our laboratory at TCSUH, we have been conducting a series of experiments to explore various mechanical applications using HTS. We have constructed a 30 lb. model flywheel levitated by a hybrid superconducting magnetic bearing (HSMB). We are also developing a levitated and vibration-dampled platform for high precision instrumentation. These applications would be ideal for space usages where ambient temperature is adequate for HTS to operate properly under greatly reduced cryogenic requirements. We will give a general overview of these potential applications and discuss the operating principles of the HTS devices we have developed.

  14. High temperature superconductor materials and applications

    NASA Technical Reports Server (NTRS)

    Doane, George B., III. (Editor); Banks, Curtis; Golben, John

    1991-01-01

    One of the areas concerned itself with the investigation of the phenomena involved in formulating and making in the laboratory new and better superconductor material with enhanced values of critical current and temperature. Of special interest were the chemistry, physical processes, and environment required to attain these enhanced desirable characteristics. The other area concerned itself with producing high temperature superconducting thin films by pulsed laser deposition techniques. Such films are potentially very useful in the detection of very low power signals. To perform this research high vacuum is required. In the course of this effort, older vacuum chambers were maintained and used. In addition, a new facility is being brought on line. This latter activity has been replete with the usual problems of bringing a new facility into service. Some of the problems are covered in the main body of this report.

  15. Hole-doped cuprate high temperature superconductors

    NASA Astrophysics Data System (ADS)

    Chu, C. W.; Deng, L. Z.; Lv, B.

    2015-07-01

    Hole-doped cuprate high temperature superconductors have ushered in the modern era of high temperature superconductivity (HTS) and have continued to be at center stage in the field. Extensive studies have been made, many compounds discovered, voluminous data compiled, numerous models proposed, many review articles written, and various prototype devices made and tested with better performance than their nonsuperconducting counterparts. The field is indeed vast. We have therefore decided to focus on the major cuprate materials systems that have laid the foundation of HTS science and technology and present several simple scaling laws that show the systematic and universal simplicity amid the complexity of these material systems, while referring readers interested in the HTS physics and devices to the review articles. Developments in the field are mostly presented in chronological order, sometimes with anecdotes, in an attempt to share some of the moments of excitement and despair in the history of HTS with readers, especially the younger ones.

  16. Magnetic suspension using high temperature superconducting cores

    NASA Technical Reports Server (NTRS)

    Scurlock, R. G.

    1992-01-01

    The development of YBCO high temperature superconductors, in wire and tape forms, is rapidly approaching the point where the bulk transport current density j vs magnetic field H characteristics with liquid nitrogen cooling will enable its use in model cores. On the other hand, BSCCO high temperature superconductor in wire form has poor j-H characteristics at 77 K today, although with liquid helium or hydrogen cooling, it appears to be superior to NbTi superconductor. Since liquid nitrogen cooling is approx. 100 times cheaper than liquid helium cooling, the use of YBCO is very attractive for use in magnetic suspension. The design is discussed of a model core to accommodate lift and drag loads up to 6000 and 3000 N respectively. A comparison is made between the design performance of a liquid helium cooled NbTi (or BSCCO) superconducting core and a liquid nitrogen cooled YBCO superconducting core.

  17. Trends in Surface Temperature at High Latitudes

    NASA Technical Reports Server (NTRS)

    Comiso, Josefino C.

    2012-01-01

    The earliest signal of a climate change is expected to be found in the polar regions where warming is expected to be amplified on account of ice-albedo feedbacks associated with the high reflectivity of snow and ice. Because of general inaccessibility, there is a general paucity of in situ data and hence the need to use satellite data to observe the large-scale variability and trends in surface temperature in the region. Among the most important sensors for monitoring surface temperature has been the Advanced Very High Resolution Radiometer (AVHRR) which was first launched in 1978 and has provided continuous thermal infrared data since 1981. The top of the atmosphere data are converted to surface temperature data through various schemes that accounts for the unique atmospheric and surface conditions in the polar regions. Among the highest source of error in the data is cloud masking which is made more difficult in the polar region because of similar Signatures of clouds and snow lice covered areas. The availability of many more channels in the Moderate Resolution Imaging Spectroradiometer (MODIS) launched on board Terra satellite in December 1999 and on board Aqua in May 2002 (e.g., 36 visible and infrared channels compared to 5 for AVHRR) made it possible to minimize the error. Further capabilities were introduced with the Advanced Microwave Scanning Radiometer (AMSR) which has the appropriate frequency channels for the retrieval of sea surface temperature (SST). The results of analysis of the data show an amplified warming in the Arctic region, compared with global warming. The spatial distribution of warming is, however, not uniform and during the last 3 decades, positive temperature anomalies have been most pronounced in North America, Greenland and the Arctic basin. Some regions of the Arctic such as Siberia and the Bering Sea surprisingly show moderate cooling but this may be because these regions were anomalously warm in the 1980s when the satellite record

  18. A high temperature superconductivity communications flight experiment

    NASA Technical Reports Server (NTRS)

    Ngo, P.; Krishen, K.; Arndt, D.; Raffoul, G.; Karasack, V.; Bhasin, K.; Leonard, R.

    1992-01-01

    The proposed high temperature superconductivity (HTSC) millimeter-wave communications flight experiment from the payload bay of the Space Shuttle Orbiter to the Advanced Communications Technology Satellite (ACTS) in geosynchronous orbit is described. The experiment will use a Ka-band HTSC phased array antenna and front-end electronics to receive a downlink communications signal from the ACTS. The discussion covers the system configuration, a description of the ground equipment, the spacecraft receiver, link performance, thermal loading, and the superconducting antenna array.

  19. Atomic absorption spectroscopy with high temperature flames.

    PubMed

    Willis, J B

    1968-07-01

    An account is given of the history of the development of high temperature flames for the atomic absorption measurement of metals forming refractory oxides. The principles governing the design of premix burners for such flames, and the relative merits of different types of nebulizer burner systems are described. After a brief account of the structure and emission characteristics of the premixed oxygen-acetylene and nitrous oxide-acetylene flames, the scope and limitations of the latter flame in chemical analysis are discussed.

  20. Intermetallic-Based High-Temperature Materials

    SciTech Connect

    Sikka, V.K.

    1999-04-25

    The intermetallic-based alloys for high-temperature applications are introduced. General characteristics of intermetallics are followed by identification of nickel and iron aluminides as the most practical alloys for commercial applications. An overview of the alloy compositions, melting processes, and mechanical properties for nickel and iron aluminizes are presented. The current applications and commercial producers of nickel and iron aluminizes are given. A brief description of the future prospects of intermetallic-based alloys is also given.

  1. Establishment of Harrop, High-Temperature Viscometer

    SciTech Connect

    Schumacher, R.F.

    1999-11-05

    This report explains how the Harrop, High-Temperature Viscometer was installed, calibrated, and operated. This report includes assembly and alignment of the furnace, viscometer, and spindle, and explains the operation of the Brookfield Viscometer, the Harrop furnace, and the UDC furnace controller. Calibration data and the development of the spindle constant from NIST standard reference glasses is presented. A simple operational procedure is included.

  2. High temperature, flexible, fiber-preform seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor); Strocky, Paul J. (Inventor)

    1992-01-01

    A seal is mounted in a rectangular groove in a movable structural panel. The seal comprises a fiber preform constructed of multiple layers of fiber having a uniaxial core. Helical fibers are wound over the core. The fibers are of materials capable of withstanding high temperatures and are both left-hand and right-hand wound. An outer layer wrapped over said helical fibers prevents abrasion damage.

  3. Thermal fuse for high-temperature batteries

    DOEpatents

    Jungst, Rudolph G.; Armijo, James R.; Frear, Darrel R.

    2000-01-01

    A thermal fuse, preferably for a high-temperature battery, comprising leads and a body therebetween having a melting point between approximately 400.degree. C. and 500.degree. C. The body is preferably an alloy of Ag--Mg, Ag--Sb, Al--Ge, Au--In, Bi--Te, Cd--Sb, Cu--Mg, In--Sb, Mg--Pb, Pb--Pd, Sb--Zn, Sn--Te, or Mg--Al.

  4. Passivation Of High-Temperature Superconductors

    NASA Technical Reports Server (NTRS)

    Vasquez, Richard P.

    1991-01-01

    Surfaces of high-temperature superconductors passivated with native iodides, sulfides, or sulfates formed by chemical treatments after superconductors grown. Passivating compounds nearly insoluble in and unreactive with water and protect underlying superconductors from effects of moisture. Layers of cuprous iodide and of barium sulfate grown. Other candidate passivating surface films: iodides and sulfides of bismuth, strontium, and thallium. Other proposed techniques for formation of passivating layers include deposition and gas-phase reaction.

  5. High Temperature Decomposition of Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2004-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydropemxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  6. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2005-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  7. Caldron For High-Temperature Alloys

    NASA Technical Reports Server (NTRS)

    Geringer, Henry J.

    1989-01-01

    Induction-heated caldron melts high-temperature alloys. Prevents sort of contamination of melts occurring during arc melting in ceramic crucibles. Liquefies 200 grams of solid metal components of alloy like niobium aluminum and makes alloy homogeneous in less than 3 minutes. Plugged sleeve constitutes main body of caldron. Coolant flows through sleeve to prevent it from melting. Mandrel-wound induction coils adjusted to tune source of power. Also serves as mold for casting alloys into such shapes as bars.

  8. High Temperature Strain Gage Calibration Fixture

    NASA Technical Reports Server (NTRS)

    Vranas, T. (Inventor)

    1976-01-01

    An apparatus and method are described for calibrating high temperature strain gases which serve for both dead weight and constant deflection measurements. A cantilever support arm allows the test unit to slide into a furnace while one end is subjected to bending strain either by hanging weights upon it or by deflecting it with a push rod. The dual nature of the fixture permits both tests to be run without change of the test specimen or removal from the furnace.

  9. Brine evolution and mineral deposition in hydrologically open evaporite basins

    USGS Publications Warehouse

    Sanford, W.E.; Wood, W.W.

    1991-01-01

    A lumped-parameter, solute mass-balance model is developed to define the role of water outflow from a well-mixed basin. A mass-balance model is analyzed with a geochemical model designed for waters with high ionic strengths. Two typical waters, seawater and a Na-HCO3 ground water, are analyzed to illustrate the control that the leakage ratio (or hydrologic openness of the basin) has on brine evolution and the suite and thicknesses of evaporite minerals deposited. The analysis suggests that brines evolve differently under different leakage conditions. -from Authors

  10. The enigmatic nitrogen biogeochemistry of Lake Vida, Antarctica: an isolated brine cryoecosystem

    NASA Astrophysics Data System (ADS)

    Ostrom, N. E.; Murray, A.; Trubl, G. G.; Kuhn, E.

    2013-12-01

    Lake Vida, located in Victoria Valley, East Antarctica, harbors ice-entrained brine (20 % salt, > 6 times seawater) that has been isolated from the surface for more than 2,800 years. The brine conditions (permanently dark, temperature of -13.4 °C, lack of O2, and pH of 6.2) and geochemistry are highly unusual. As an example, the brine contains the highest concentrations of N2O reported for any aquatic ecosystem (86.6 μM) and exceptionally high levels of NH4+ (3.6 mM), NO3- (1.1 mM) and NO2- (27.3 μM). Though this cryoecosystem appears to be relatively inhospitable, microbial life is abundant (>10^7 cell-like particles per mL), is capable of protein production at in situ temperatures, and harbors an assemblage of bacterial phylotypes spanning at least eight phyla. To assess present and past microbial activity in situ and test hypotheses concerning energy generation in the brine cryoecosystem, the stable isotope signatures of nitrogen, oxygen, and hydrogen have been characterized in liquid and dissolved gas phases. The isotopic compositions of nitrate (δ15N = -7.9 ‰, δ18O = 31.7 ‰), ammonium (δ15N = -4.8 ‰) and dinitrogen (δ15N = 0.3 ‰) are all consistent with an atmospheric origin. Given that nearly all non-atmospheric sources of nitrate lack a 17O anomaly, a Δ17O value of nitrate in Lake Vida of 15.9 ‰ suggests that approximately half of the nitrate present is derived from atmospheric deposition. A 17O anomaly was not observed in N2O indicating that this gas was likely formed in the lake. While the bulk δ15N (-22.2 ‰) and site preference (SP; -3.6 ‰) values for N2O are consistent with a microbial origin, the δ18O value (3.0 ‰) is markedly depleted in 18O relative to the vast majority of published values. The soils surrounding Don Juan Pond, which is in a neighboring valley, have been shown to produce N2O with variable δ15N, δ18O and SP values of -45.4 to -34.5 ‰, 50.5 to 76.7 ‰, and -45.2 to 4.1 ‰, respectively, that may reflect

  11. Improved Water Flooding through Injection Brine Modification

    SciTech Connect

    Robertson, Eric Partridge; Thomas, Charles Phillip; Morrow, Norman

    2003-01-01

    Crude oil/brine/rock interactions can lead to large variations in the displacement efficiency of waterflooding, by far the most widely applied method of improved oil recovery. Laboratory waterflood tests show that injection of dilute brine can increase oil recovery. Numerous fields in the Powder River basin have been waterflooded using low salinity brine (about 500 ppm) from the Madison limestone or Fox Hills sandstone. Although many uncertainties arise in the interpretation and comparison of field production data, injection of low salinity brine appears to give higher recovery compared to brine of moderate salinity (about 7,000 ppm). Laboratory studies of the effect of brine composition on oil recovery cover a wide range of rock types and crude oils. Oil recovery increases using low salinity brine as the injection water ranged from a low of no notable increase to as much as 37.0% depending on the system being studied. Recovery increases using low salinity brine after establishing residual oil saturation (tertiary mode) ranged from no significant increase to 6.0%. Tests with two sets of reservoir cores and crude oil indicated slight improvement in recovery for low salinity brine. Crude oil type and rock type (particularly the presence and distribution of kaolinite) both play a dominant role in the effect that brine composition has on waterflood oil recovery.

  12. Nickel alloys combat high-temperature corrosion

    SciTech Connect

    Agarwal, D.C.; Herda, W.R.; Brill, U.

    1995-10-01

    During the last few decades, a better understanding of alloying effects, advances in melting technology, and the development of controlled thermomechanical processing have led to new and improved high-temperature alloys. Most such alloys have sufficient amounts of chromium (with or without additions of aluminum or silicon) to form chromium oxide, alumina, and/or silica protective oxide scales, which provide resistance to environmental degradation. However, oxides cannot protect against failure by creep, mechanical or thermal fatigue, thermal shock, or embrittlement. In the real world, failure is typically caused by a combination of two or more attack modes, which synergistically accelerate degradation. To counter these attacks, two new nickel-base alloys have been developed, in which high-temperature corrosion resistance has been optimized by the careful addition of elements such as chromium, aluminum, silicon, and rare earths. They provide economical and reliable solutions to attack by oxygen, sulfur, halogens, carbon compounds, and nitrogen in a range of high-temperature applications. For example, Alloy 602CA is utilized in heat treating equipment, catalytic automotive parts, and chemical processing apparatus. Alloy 45TM has been successfully used in coal gasification equipment, incinerators, refineries, and process machinery involving severe sulfidizing conditions.

  13. High Temperature VARTM of Phenylethynyl Terminated Imides

    NASA Technical Reports Server (NTRS)

    Ghose, Sayata; Cano, Roberto J.; Watson, Kent A.; Britton, Sean M.; Jensen, Brian J.; Connell, John W.; Herring, Helen M.; Linberry, Quentin J.

    2009-01-01

    Depending on the part type and quantity, fabrication of composite structures using vacuum assisted resin transfer molding (VARTM) can be more affordable than conventional autoclave techniques. Recent efforts have focused on adapting VARTM for the fabrication of high temperature composites. Due to their low melt viscosity and long melt stability, certain phenylethynyl terminated imides (PETI) can be processed into composites using high temperature VARTM (HT-VARTM). However, one of the disadvantages of the current HT-VARTM resin systems has been the high porosity of the resultant composites. For aerospace applications, the desired void fraction of less than 2% has not yet been achieved. In the current study, two PETI resins, LaRC PETI-330 and LaRC PETI-8 have been used to make test specimens using HT-VARTM. The resins were infused into ten layers of IM7-6K carbon fiber 5-harness satin fabric at 260 C or 280 C and cured at temperature up to 371 C. Initial runs yielded composites with high void content, typically greater than 7% by weight. A thermogravimetric-mass spectroscopic study was conducted to determine the source of volatiles leading to high porosity. It was determined that under the thermal cycle used for laminate fabrication, the phenylethynyl endcap was undergoing degradation leading to volatile evolution. This finding was unexpected as high quality composite laminates have been fabricated under higher pressures using these resin systems. The amount of weight loss experienced during the thermal cycle was only about 1% by weight, but this leads to a significant amount of volatiles in a closed system. By modifying the thermal cycle used in laminate fabrication, the void content was significantly reduced (typically 3% or less). The results of this work are presented herein.

  14. Thermal and density stratification in a seafloor brine pool, northern Gulf of Mexico

    SciTech Connect

    MacDonald, I.R. )

    1996-01-01

    Brine Pool NR-1 is located on the continental slope of the Gulf of Mexico at a site where a salt diapir has penetrated the near subbottom. The pool sits atop a low cone that rises about 10 in above the surrounding seafloor. It has a distinct sea water-brine interface at a water depth of 650 m. It is about 10 m in diameter and is surrounded by a very dense colony of mussels that possess methanotrophic symbionts. The fluid in the upper layer has a salinity [approximately]120 psu and contains high concentrations of dissolved methane. A continuous stream of methane bubbles vents from a localized region near the center of the pool I used a small winch, mounted on submarine Johnson Sea-Link I to lower a CTD (modified for high salinity) into the pool at various points and also used a pole to probe the depth of the pool in the shallower parts. The pool was funnel-shaped, a couple of cm deep in the edges and less than 2 m deep across most of the pool area, but over 33 m deep at the point where the bubbles were venting. The CTD record shows that temperature increases abruptly at the brine-seawater interface and forms a second thermocline within the brine column. Conductivity also increases abruptly at the interface, consistent with the high salinity of the pool. Remarkably, conductivity decreases at the same brine depth as the thermocline, is erratic for several meters, and then becomes constant to the bottom of the pool. This unusual stratification is maintained by the mixing energy of the bubble stream, which is sufficient to maintain a large volume of suspended sediment. The suspended sediment interferes with the conductivity cell on the CTD to produce the anomalous reading. This stability of this system is determined by the gas venting rate and the shape of the pool and diatreme. Stratification of the fluid may serve to extend the life of the pool.

  15. High temperature inorganic membranes for separating hydrogen

    SciTech Connect

    Fain, D.E.; Roettger, G.E.

    1995-08-01

    Effort has continued to accumulate data on the transport of gases over the temperature range from room temperature to 275{degrees}C with inorganic membranes having a range of pore radii from approximately 0.25 nm to 3 mn. An experimental alumina membrane having an estimated mean pore radius of 0.25 nm has been fabricated and tested. Extensive testing of this membrane indicated that the separation factor for helium and carbon tetrafluoride at 250{degrees}C was 59 and the extrapolated high temperature separation factor was 1,193. For safety reasons, earlier flow measurements concentrated on helium, carbon dioxide, and carbon tetrafluoride. New data have been acquired with hydrogen to verify the agreement with the other gases. During the measurements with hydrogen, it was noted that a considerable amount of moisture was present in the test gas. The source of this moisture and its effect on permeance was examined. Improvements were implemented to the flow test system to minimize the water content of the hydrogen test gas, and subsequent flow measurements have shown excellent results with hydrogen. The extrapolation of separation factors as a function of temperature continues to show promise as a means of using the hard sphere model to determine the pore size of membranes. The temperature dependence of helium transport through membranes appears to be considerably greater than other gases for the smallest pore sizes. The effort to extend temperature dependence to the hard sphere model continues to be delayed, primarily because of a lack of adequate adsorption data.

  16. Precipitation Hardenable High Temperature Shape Memory Alloy

    NASA Technical Reports Server (NTRS)

    Noebe, Ronald Dean (Inventor); Draper, Susan L. (Inventor); Nathal, Michael V. (Inventor); Crombie, Edwin A. (Inventor)

    2010-01-01

    A composition of the invention is a high temperature shape memory alloy having high work output, and is made from (Ni+Pt+Y),Ti(100-x) wherein x is present in a total amount of 49-55 atomic % Pt is present in a total amount of 10-30 atomic %, Y is one or more of Au, Pd. and Cu and is present in a total amount of 0 to 10 atomic %. The alloy has a matrix phase wherein the total concentration of Ni, Pt, and the one or more of Pd. Au, and Cu is greater than 50 atomic %.

  17. Structural relationships in high temperature superconductors

    SciTech Connect

    Schuller, I.K.; Segre, C.U.; Hinks, D.G.; Jorgensen, J.D.; Soderholm, L.; Beno, M.; Zhang, K.

    1987-09-01

    The recent discovery of two types of metallic copper oxide compounds which are superconducting to above 90/sup 0/K has renewed interest in the search for new high temperature superconducting materials. It is significant that both classes of compounds, La/sub 2-x/Sr/sub x/CuO/sub 4-y/ and YBa/sub 2/Cu/sub 3/O/sub 7-delta/ are intimately related to the extensively studied perovskite family. Both compounds contain highly oxidized, covalently bonded Cu-O sublattices, however, they differ in geometry. In this paper we discuss the relationship of these features to the superconducting properties. 30 refs., 6 figs.

  18. High temperature aqueous stress corrosion testing device

    DOEpatents

    Bornstein, A.N.; Indig, M.E.

    1975-12-01

    A description is given of a device for stressing tensile samples contained within a high temperature, high pressure aqueous environment, thereby permitting determination of stress corrosion susceptibility of materials in a simple way. The stressing device couples an external piston to an internal tensile sample via a pull rod, with stresses being applied to the sample by pressurizing the piston. The device contains a fitting/seal arrangement including Teflon and weld seals which allow sealing of the internal system pressure and the external piston pressure. The fitting/seal arrangement allows free movement of the pull rod and the piston.

  19. The solubility of noble gases in water and in NaCl brine

    NASA Astrophysics Data System (ADS)

    Smith, S. P.; Kennedy, B. M.

    1983-03-01

    can also be used to estimate the temperature and concentration dependence of the salt effect for other alkali halides. Extrapolation of the measured data is not possible due to the incompletely-characterized minima in the temperature dependence of the salting coefficients. The regularities in the data observed at low temperatures suggest relatively few high-temperature data will be required to model the behavior of noble gases in high-temperature geothermal brines.

  20. High Temperature Wear of Advanced Ceramics

    NASA Technical Reports Server (NTRS)

    DellaCorte, C.

    2005-01-01

    It was initially hypothesized that advanced ceramics would exhibit favorable high te- friction and wear properties because of their high hot hardness and low achievable surface roughness welding observed in metals does not occur in ceramics. More recent tribological studies of many nitride, carbide, oxide and composite ceramics, however, have revealed that ceramics often exhibit high friction and wear in non-lubricated, high temperature sliding contacts. A summary is given to measure friction and wear factor coefficients for a variety of ceramics from self mated ceramic pin-on-disk tests at temperatures from 25 to up to 1200 C. Observed steady state friction coefficients range from about 0.5 to 1.0 or above. Wear factor coefficients are also very high and range from about to 10(exp -5) to 10(exp -2) cubic millimeters per N-m. By comparison, oil lubricated steel sliding results in friction coefficients of 0.1 or less and wear factors less than 10(exp -9) cubic millimeters per N-m.