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Sample records for liquid metallic hydrogen

  1. Liquid Metallic Hydrogen: A Building Block for the Liquid Sun

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2011-07-01

    Full Text Available Liquid metallic hydrogen provides a compelling material for constructing a condensed matter model of the Sun and the photosphere. Like diamond, metallic hydrogen might have the potential to be a metastable substance requiring high pressures for forma- tion. Once created, it would remain stable even at lower pressures. The metallic form of hydrogen was initially conceived in 1935 by Eugene Wigner and Hillard B. Huntington who indirectly anticipated its elevated critical temperature for liquefaction (Wigner E. and Huntington H.B. On the possibility of a metallic modification of hydro- gen. J. Chem. Phys. , 1935, v.3, 764–770. At that time, solid metallic hydrogen was hypothesized to exist as a body centered cubic, although a more energetically accessible layered graphite-like lattice was also envisioned. Relative to solar emission, this struc- tural resemblance between graphite and layered metallic hydrogen should not be easily dismissed. In the laboratory, metallic hydrogen remains an elusive material. However, given the extensive observational evidence for a condensed Sun composed primarily of hydrogen, it is appropriate to consider metallic hydrogen as a solar building block. It is anticipated that solar liquid metallic hydrogen should possess at least some layered order. Since layered liquid metallic hydrogen would be essentially incompressible, its invocation as a solar constituent brings into question much of current stellar physics. The central proof of a liquid state remains the thermal spectrum of the Sun itself. Its proper understanding brings together all the great forces which shaped modern physics. Although other proofs exist for a liquid photosphere, our focus remains solidly on the generation of this light.

  2. Hydrogen permeation resistant layers for liquid metal reactors

    International Nuclear Information System (INIS)

    McGuire, J.C.

    1980-03-01

    Reviewing the literature in the tritium diffusion field one can readily see a wide divergence in results for both the response of permeation rate to pressure, and the effect of oxide layers on total permeation rates. The basic mechanism of protective oxide layers is discussed. Two coatings which are less hydrogen permeable than the best naturally occurring oxide are described. The work described is part of an HEDL-ANL cooperative research program on Tritium Permeation in Liquid Metal Cooled Reactors. This includes permeation work on hydrogen, deuterium, and tritium with the hydrogen-deuterium research leading to the developments presented

  3. Problems of hydrogen - water vapor - inert gas mixture use in heavy liquid metal coolant technology

    International Nuclear Information System (INIS)

    Ul'yanov, V.V.; Martynov, P.N.; Gulevskij, V.A.; Teplyakov, Yu.A.; Fomin, A.S.

    2014-01-01

    The reasons of slag deposit formation in circulation circuits with heavy liquid metal coolants, which can cause reactor core blockage, are considered. To prevent formation of deposits hydrogen purification of coolant and surfaces of circulation circuit is used. It consists in introduction of gaseous mixtures hydrogen - water vapor - rare gas (argon or helium) directly into coolant flow. The principle scheme of hydrogen purification and the processes occurring during it are under consideration. Measures which make it completely impossible to overlap of the flow cross section of reactor core, steam generators, pumps and other equipment by lead oxides in reactor facilities with heavy liquid metal coolants are listed [ru

  4. Potential of multi-purpose liquid metallic fuelled fast reactor (MPFR) as a hydrogen production system

    International Nuclear Information System (INIS)

    Endo, H.; Ninokata, H.; Netchaev, A.; Sawada, T.

    2001-01-01

    Nuclear energy is the only effective alternative energy source to fossil fuels in the next century. Therefore future nuclear power plants should satisfy the following three requirements: i) multiple energy conversion capability with high temperature not only for electricity generation but also for hydrogen production, ii) extended siting capability so as to eliminate on-site refuelling, and iii) passive safety features. An aim of this paper is to describe the basic concept of the multi-purpose liquid metallic fuelled fast reactor system (MPFR). The MPFR introduces the U-Pu-X (X: Mn, Fe, Co) liquid metallic alloy with Ta and Ta/TaC structural materials, and satisfies all of the conditions listed above based on the following characteristics of the liquid metallic fuel: high temperature operation between 650 deg C (sodium-cooled system) and 1 200 deg C (lead-cooled system), a core lifetime of 15-30 years without radiation damage of fuel materials, and enhanced passive safety by the thermal expansion of liquid fuel and the avoidance of re-criticality due to local core fuel dispersion at fuel failure events. (authors)

  5. Liquid Metallic Hydrogen II. A Critical Assessment of Current and Primordial Helium Levels in the Sun

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-04-01

    Full Text Available Before a solar model becomes viable in astrophysics, one mus t consider how the ele- mental constitution of the Sun was ascertained, especially relative to its principle com- ponents: hydrogen and helium. Liquid metallic hydrogen has been proposed as a solar structural material for models based on condensed matter (e .g. Robitaille P.-M. Liq- uid Metallic Hydrogen: A Building Block for the Liquid Sun. Progr. Phys. , 2011, v. 3, 60–74. There can be little doubt that hydrogen plays a d ominant role in the uni- verse and in the stars; the massive abundance of hydrogen in t he Sun was established long ago. Today, it can be demonstrated that the near isointe nse nature of the Sun’s Balmer lines provides strong confirmatory evidence for a dis tinct solar surface. The situation relative to helium remains less conclusive. Stil l, helium occupies a prominent role in astronomy, both as an element associated with cosmol ogy and as a byproduct of nuclear energy generation, though its abundances within the Sun cannot be reliably estimated using theoretical approaches. With respect to th e determination of helium lev- els, the element remains spectroscopically silent at the le vel of the photosphere. While helium can be monitored with ease in the chromosphere and the prominences of the corona using spectroscopic methods, these measures are hig hly variable and responsive to elevated solar activity and nuclear fragmentation. Dire ct assays of the solar winds are currently viewed as incapable of providing definitive in formation regarding solar helium abundances. As a result, insight relative to helium r emains strictly based on the- oretical estimates which couple helioseismological appro aches to metrics derived from solar models. Despite their “state of the art” nature, heliu m estimates based on solar models and helioseismology are suspect on several fronts, i ncluding their reliance on solar opacities. The best knowledge can only come from the so

  6. Liquid metal purification device

    International Nuclear Information System (INIS)

    Sakai, Takao; Shimoyashiki, Shigehiro.

    1992-01-01

    The device of the present invention concerns a liquid metal purification device for removing and purifying impuries in liquid metal sodium used as coolants of an FBR type reactor. A vessel having a group of pipes made of hydrogen permeable metal at the inside thereof is disposed to the inlet pipeline of a cold trap. The group of hydrogen permeable metal pipes is connected to an exhaust pipe and a vacuum pump, so that the inside of the pipes is exhausted. Liquid metal sodium branched from the main pipeline of a coolant system passes through the outer side of the group of the hydrogen permeable metal pipes. In this cae, hydrogen contained as impurities in the liquid metal sodium diffuses and permeates the hydrogen permeation metal pipes and enters into the pipe group and is discharged out of the system by the vacuum pump. This can mitigate the hydrogen removing burden of the cold trap, to extend the device life time. (I.N.)

  7. The effect of a micro bubble dispersed gas phase on hydrogen isotope transport in liquid metals under nuclear irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Fradera, J., E-mail: jfradera@ubu.es; Cuesta-López, S., E-mail: scuesta@ubu.es

    2013-12-15

    The present work intend to be a first step towards the understanding and quantification of the hydrogen isotope complex phenomena in liquid metals for nuclear technology. Liquid metals under nuclear irradiation in, e.g., breeding blankets of a nuclear fusion reactor would generate tritium which is to be extracted and recirculated as fuel. At the same time that tritium is bred, helium is also generated and may precipitate in the form of nano bubbles. Other liquid metal systems of a nuclear reactor involve hydrogen isotope absorption processes, e.g., tritium extraction system. Hence, hydrogen isotope absorption into gas bubbles modelling and control may have a capital importance regarding design, operation and safety. Here general models for hydrogen isotopes transport in liquid metal and absorption into gas phase, that do not depend on the mass transfer limiting regime, are exposed and implemented in OpenFOAM® CFD tool for 0D–3D simulations. Results for a 0D case show the impact of a He dispersed phase of nano bubbles on hydrogen isotopes inventory at different temperatures as well as the inventory evolution during a He nucleation event. In addition, 1D and 2D axisymmetric cases are exposed showing the effect of a He dispersed gas phase on hydrogen isotope permeation through a lithium lead eutectic alloy and the effect of vortical structures on hydrogen isotope transport at a backward facing step. Exposed results give a valuable insight on current nuclear technology regarding the importance of controlling hydrogen isotope transport and its interactions with nucleation event through gas absorption processes.

  8. Liquid hydrogen in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Yasumi, S. [Iwatani Corp., Osaka (Japan). Dept. of Overseas Business Development

    2009-07-01

    Japan's Iwatani Corporation has focused its attention on hydrogen as the ultimate energy source in future. Unlike the United States, hydrogen use and delivery in liquid form is extremely limited in the European Union and in Japan. Iwatani Corporation broke through industry stereotypes by creating and building Hydro Edge Co. Ltd., Japan's largest liquid hydrogen plant. It was established in 2006 as a joint venture between Iwatani and Kansai Electric Power Group in Osaka. Hydro Edge is Japan's first combined liquid hydrogen and ASU plant, and is fully operational. Liquid oxygen, liquid nitrogen and liquid argon are separated from air using the cryogenic energy of liquefied natural gas fuel that is used for power generation. Liquid hydrogen is produced efficiently and simultaneously using liquid nitrogen. Approximately 12 times as much hydrogen in liquid form can be transported and supplied as pressurized hydrogen gas. This technology is a significant step forward in the dissemination and expansion of hydrogen in a hydrogen-based economy.

  9. Metallic hydrogen research

    International Nuclear Information System (INIS)

    Burgess, T.J.; Hawke, R.S.

    1978-01-01

    Theoretical studies predict that molecular hydrogen can be converted to the metallic phase at very high density and pressure. These conditions were achieved by subjecting liquid hydrogen to isentropic compression in a magnetic-flux compression device. Hydrogen became electrically conducting at a density of about 1.06 g/cm 3 and a calculated pressure of about 2 Mbar. In the experimental device, a cylindrical liner, on implosion by high explosive, compresses a magnetic flux which in turn isentropically compresses a hydrogen sample; coaxial conical anvils prevent escape of the sample during compression. One anvil contains a coaxial cable that uses alumina ceramic as an insulator; this probe allows continuous measurement of the electrical conductivity of the hydrogen. A flash x-ray radiograph exposed during the experiment records the location of the sample-tube boundaries and permits calculation of the sample density. The theoretical underpinnings of the metallic transition of hydrogen are briefly summarized, and the experimental apparatus and technique, analytical methods, and results are described. 9 figures

  10. Metal nanoparticles/ionic liquid/cellulose: polymeric membrane for hydrogenation reactions

    Directory of Open Access Journals (Sweden)

    Marcos Alexandre Gelesky

    2014-01-01

    Full Text Available Rhodium and platinum nanoparticles were supported in polymeric membranes with 10, 20 and 40 µm thickness. The polymeric membranes were prepared combining cellulose acetate and the ionic liquid (IL 1-n-butyl-3-methylimidazolium bis(trifluoromethane sulfonylimide (BMI.(NTf2. The presence of metal nanoparticles induced an increase in the polymeric membrane surface areas. The increase of the IL content resulted in an improvement of elasticity and decrease in tenacity and toughness, whereas the stress at break was not affected. The presence of IL probably causes an increase in the separation between the cellulose molecules that result in a higher flexibility and processability of the polymeric membrane. The CA/IL/M(0 combinations exhibit an excellent synergistic effect that enhances the activity and durability of the catalyst for the hydrogenation of cyclohexene. The CA/IL/M(0 polymeric membrane displays higher catalytic activity (up to 7.353 h-1 for the 20 mm of CA/IL/Pt(0 and stability than the nanoparticles dispersed only in the IL.

  11. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere VII. Further Insights into the Chromosphere and Corona

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-07-01

    Full Text Available In the liquid metallic hydrogen model of the Sun, the chromosphere is responsible for the capture of atomic hydrogen in the solar atmosphere and its eventual re-entry onto the photospheric surface (P.M. Robitaille. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere IV. On the Nature of the Chromosphere. Prog. Phys., 2013, v. 3, L15–L21. As for the corona, it represents a diffuse region containing both gaseous plasma and condensed matter with elevated electron affinity (P.M. Robitaille. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere V. On the Nature of the Corona. Prog. Phys., 2013, v. 3, L22–L25. Metallic hydrogen in the corona is thought to enable the continual harvest of electrons from the outer reaches of the Sun, thereby preserving the neutrality of the solar body. The rigid rotation of the corona is offered as the thirty-third line of evidence that the Sun is comprised of condensed matter. Within the context of the gaseous models of the Sun, a 100 km thick transition zone has been hypothesized to exist wherein temperatures increase dramatically from 104–106 K. Such extreme transitional temperatures are not reasonable given the trivial physical scale of the proposed transition zone, a region adopted to account for the ultra-violet emission lines of ions such as C IV, O IV, and Si IV. In this work, it will be argued that the transition zone does not exist. Rather, the intermediate ionization states observed in the solar atmosphere should be viewed as the result of the simultaneous transfer of protons and electrons onto condensed hydrogen structures, CHS. Line emissions from ions such as C IV, O IV, and Si IV are likely to be the result of condensation reactions, manifesting the involvement of species such as CH4, SiH4, H3O+ in the synthesis of CHS in the chromosphere. In addition, given the presence of a true solar surface at the level of the photosphere in the liquid metallic hydrogen model

  12. Hydrogen-metal systems

    International Nuclear Information System (INIS)

    Wenzl, H.; Springer, T.

    1976-01-01

    A survey is given on the alloys of metal crystals with hydrogen. The system niobium-hydrogen and its properties are especially dealt with: diffusion and heat of solution of hydrogen in the host crystal, phase diagram, coherent and incoherent phase separation, application of metal-hydrogen systems in technology. Furthermore, examples from research work in IFF (Institut fuer Festkoerperforschung) of the Nuclear Research Plant, Juelich, in the field of metal-H systems are given in summary form. (GSC) [de

  13. Transient shielded liquid hydrogen containers

    International Nuclear Information System (INIS)

    Varghese, A.P.; Herring, R.H.

    1990-01-01

    The storage of hydrogen in the liquid phase has been limited in duration due to the thermal performance constraints of conventional Liquid Hydrogen containers available. Conventional Liquid Hydrogen containers lose hydrogen because of their relatively high heat leak and variations in usage pattern of hydrogen due to shutdowns. Local regulations also discourage venting of hydrogen. Long term storage of Liquid Hydrogen without product loss was usually accomplished using Liquid Nitrogen sacrificial shields. This paper reports on a new low heat leak container developed and patented that will extend the storage time of liquid hydrogen by five hundred percent. The principle of operation of the Transient Shields which makes the extraordinary performance of this container feasible is described in this paper. Also covered are the impact of this new container on present applications of hydrogen and the new opportunities afforded to Liquid hydrogen in the world hydrogen market

  14. Liquid hydrogen properties

    International Nuclear Information System (INIS)

    Choi, Jung Woon; Kim, Y. J.; Lee, K. H.; Kim, H. I.; Han, K. Y.; Park, J.H.

    2004-03-01

    The purpose of this report is to provide the input data, whose characteristic is thermodynamic and transport, in the form of equation for the thermo-hydraulic calculations using hydrogen as a working substance. The considered data in this report are particularly focused on the properties of para-hydrogen and of equilibrium-hydrogen around the working temperature range of the HANARO-CNS. The discussed properties of hydrogen are, in turn, the pressure of saturated vapors, the density, the heat of vaporization, thermal conductivity, viscosity, and heat capacity. Several equations to fit the above-mentioned experimental data allow calculating the various properties of liquid hydrogen with high accuracy at all considered temperatures

  15. Ultrafast quenching of metals to liquid-helium temperatures - investigation of the low-temperature mobility of hydrogen in niobium

    International Nuclear Information System (INIS)

    Blanz, M.; Blocher, R.; Carstanjen, H.D.; Messer, R.; Plachke, D.; Seeger, A.

    1989-01-01

    A novel technique for ultrafast quenching from 300 K to 4.2 K has been developed. It employs a fast jet of liquid helium with a speed of about 10 2 m/s and allows us to quench metal samples in about 6 ms. This corresponds to a quenching rate of about 4.5x10 4 K/s, which exceeds that achievable by conventional quenching in liquid helium by more than one order of magnitude. The technique has been used for a resistometric study of the behaviour of hydrogen in niobium quenched-in from the α-phase by means of isochronal and isothermal annealing. Even in the low-temperature region below 20 K a considerable recovery of the resistivity has been found, which cannot be seen in conventional quenching experiments. (orig.)

  16. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere VI. Helium in the Chromosphere

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-07-01

    Full Text Available Molecular hydrogen and hydrides have recently been advanced as vital agents in the generation of emission spectra in the chromosphere. This is a result of the role they play in the formation of condensed hydrogen structures (CHS within the chromosphere (P.M. Robitaille. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere IV. On the Nature of the Chromosphere. Progr. Phys., 2013, v. 3, 15–21. Next to hydrogen, helium is perhaps the most intriguing component in this region of the Sun. Much like other elements, which combine with hydrogen to produce hydrides, helium can form the well-known helium hydride molecular ion, HeH+, and the excited neutral helium hydride molecule, HeH∗. While HeH+ is hypothesized to be a key cosmologicalmolecule, its possible presence in the Sun, and that of its excited neutral counterpart, has not been considered. Still, these hydrides are likely to play a role in the synthesis of CHS, as the He I and He II emission lines strongly suggest. In this regard, the study of helium emission spectra can provide insight into the condensed nature of the Sun, especially when considering the 10830 Å line associated with the 23P→2 3S triplet state transition. This line is strong in solar prominences and can be seen clearly on the disk. The excessive population of helium triplet states cannot be adequately explained using the gaseous models, since these states should be depopulated by collisional processes. Conversely, when He-based molecules are used to build CHS in a liquid metallic hydrogen model, an ever increasing population of the 23S and 23P states might be expected. The overpopulation of these triplet states leads to the conclusion that these emission lines are unlikely to be produced through random collisional or photon excitation, as required by the gaseous models. This provides a significant hurdle for these models. Thus, the strong 23P→2 3S lines and the overpopulation of the helium triplet

  17. Novel developments in hydrogen storage, hydrogen activation and ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Doroodian, Amir

    2010-12-03

    This dissertation is divided into three chapters. Recently, metal-free hydrogen activation using phosphorous compounds has been reported in science magazine. We have investigated the interaction between hydrogen and phosphorous compounds in presence of strong Lewis acids (chapter one). A new generation of metal-free hydrogen activation, using amines and strong Lewis acids with sterically demanding nature, was already developed in our group. Shortage of high storage capacity using large substitution to improve sterical effect led us to explore the amine borane derivatives, which are explained in chapter two. Due to the high storage capacity of hydrogen in aminoborane derivatives, we have explored these materials to extend hydrogen release. These compounds store hydrogen as proton and hydride on adjacent atoms or ions. These investigations resulted in developing hydrogen storage based on ionic liquids containing methyl guanidinium cation. Then we have continued to develop ionic liquids based on methyl guanidinium cation with different anions, such as tetrafluoro borate (chapter three). We have replaced these anions with transition metal anions to investigate hydrogen bonding and catalytic activity of ionic liquids. This chapter illustrates the world of ionic liquid as a green solvent for organic, inorganic and catalytic reactions and combines the concept of catalysts and solvents based on ionic liquids. The catalytic activity is investigated particularly with respect to the interaction with CO{sub 2}. (orig.)

  18. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere IV. On the Nature of the Chromosphere

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-07-01

    Full Text Available The chromosphere is the site of weak emission lines characterizing the flash spectrum observed for a few seconds during a total eclipse. This layer of the solar atmosphere is known to possess an opaque Hα emission and a great number of spicules, which can extend well above the photosphere. A stunning variety of hydrogen emission lines have been observed in this region. The production of these lines has provided the seventeenth line of evidence that the Sun is comprised of condensed matter (Robitaille P.M. Liquid Metallic Hydrogen II: A critical assessment of current and primordial helium levels in Sun. Progr. Phys., 2013, v. 2, 35–47. Contrary to the gaseous solar models, the simplest mechanism for the production of emission lines is the evaporation of excited atoms from condensed surfaces existing within the chromosphere, as found in spicules. This is reminiscent of the chemiluminescence which occurs during the condensation of silver clusters (Konig L., Rabin I., Schultze W., and Ertl G. Chemiluminescence in the Agglomeration of Metal Clusters. Science, v. 274, no. 5291, 1353–1355. The process associated with spicule formation is an exothermic one, requiring the transport of energy away from the site of condensation. As atoms leave localized surfaces, their electrons can occupy any energy level and, hence, a wide variety of emission lines are produced. In this regard, it is hypothesized that the presence of hydrides on the Sun can also facilitate hydrogen condensation in the chromosphere. The associated line emission from main group and transition elements constitutes the thirtieth line of evidence that the Sun is condensed matter. Condensation processes also help to explain why spicules manifest an apparently constant temperature over their entire length. Since the corona supports magnetic field lines, the random orientations associated with spicule formation suggests that the hydrogen condensates in the chromosphere are not metallic in

  19. The behavior of hydrogen in metals

    International Nuclear Information System (INIS)

    Hirabayashi, Makoto

    1975-01-01

    Explanation is made on the equilibrium diagrams of metal-hydrogen systems and the state of hydrogen in metals. Some metals perform exothermic reaction with hydrogen, and the others endothermic reaction. The former form stable hydrides and solid solutions over a wide range of composition. Hydrogen atoms in fcc and bcc metals are present at the interstitial positions of tetrahedron lattice and octahedron lattice. For example, hydrogen atoms in palladium are present at the intersititial positions of octahedron. When the ratio of the composition of hydrogen and palladium is 1:1, the structure becomes NaCl type. Hydrogen atoms in niobium and vanadium and present interstitially in tetrahedron lattice. Metal hydrides with high hydrogen concentration are becoming important recently as the containers of hydrogen. Hydrogen atoms diffuse in metals quite easily. The activation energy of the diffusion of hydrogen atoms in Nb and V is about 2-3 kcal/g.atom. The diffusion coefficient is about 10 -5 cm 2 /sec in alpha phase at room temperature. The number of jumps of a hydrogen atom between neighboring lattice sites is 10 11 --10 12 times per second. This datum is almost the same as that of liquid metals. Discussion is also made on the electronic state of hydrogen in metals. (Fukutomi, T.)

  20. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere V. On the Nature of the Corona

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-07-01

    Full Text Available The E-corona is the site of numerous emission lines associated with high ionization states (i.e. FeXIV-FeXXV. Modern gaseous models of the Sun require that these states are produced by atomic irradiation, requiring the sequential removal of electrons to infinity, without an associated electron acceptor. This can lead to computed temperatures in the corona which are unrealistic (i.e. ∼30–100 MK contrasted to solar core values of ∼16 MK. In order to understand the emission lines of the E-corona, it is vital to recognize that they are superimposed upon the K-corona, which produces a continuous spectrum, devoid of Fraunhofer lines, arising from this same region of the Sun. It has been advanced that the K-corona harbors self-luminous condensed matter (Robitaille P.M. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere II. Continuous Emission and Condensed Matter Within the Corona. Progr. Phys., 2013, v. 3, L8–L10; Robitaille P.M. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere III. Importance of Continuous Emission Spectra from Flares, Coronal Mass Ejections, Prominences, and Other Coronal Structures. Progr. Phys., 2013, v. 3, L11–L14. Condensed matter can possess elevated electron affinities which may strip nearby atoms of their electrons. Such a scenario accounts for the high ionization states observed in the corona: condensed matter acts to harness electrons, ensuring the electrical neutrality of the Sun, despite the flow of electrons and ions in the solar winds. Elevated ionization states reflect the presence of materials with high electron affinities in the corona, which is likely to be a form of metallic hydrogen, and does not translate into elevated temperatures in this region of the solar atmosphere. As a result, the many mechanisms advanced to account for coronal heating in the gaseous models of the Sun

  1. Microwave irradiation for the facile synthesis of transition-metal nanoparticles (NPs) in ionic liquids (ILs) from metal-carbonyl precursors and Ru-, Rh-, and Ir-NP/IL dispersions as biphasic liquid-liquid hydrogenation nanocatalysts for cyclohexene.

    Science.gov (United States)

    Vollmer, Christian; Redel, Engelbert; Abu-Shandi, Khalid; Thomann, Ralf; Manyar, Haresh; Hardacre, Christopher; Janiak, Christoph

    2010-03-22

    Stable chromium, molybdenum, tungsten, manganese, rhenium, ruthenium, osmium, cobalt, rhodium, and iridium metal nanoparticles (M-NPs) have been reproducibly obtained by facile, rapid (3 min), and energy-saving 10 W microwave irradiation (MWI) under an argon atmosphere from their metal-carbonyl precursors [M(x)(CO)(y)] in the ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF(4)]). This MWI synthesis is compared to UV-photolytic (1000 W, 15 min) or conventional thermal decomposition (180-250 degrees C, 6-12 h) of [M(x)(CO)(y)] in ILs. The MWI-obtained nanoparticles have a very small (TED), and dynamic light scattering (DLS)). The ruthenium, rhodium, or iridium nanoparticle/IL dispersions are highly active and easily recyclable catalysts for the biphasic liquid-liquid hydrogenation of cyclohexene to cyclohexane with activities of up to 522 (mol product) (mol Ru)(-1) h(-1) and 884 (mol product) (mol Rh)(-1) h(-1) and give almost quantitative conversion within 2 h at 10 bar H(2) and 90 degrees C. Catalyst poisoning experiments with CS(2) (0.05 equiv per Ru) suggest a heterogeneous surface catalysis of Ru-NPs.

  2. Liquid metal cold trap

    International Nuclear Information System (INIS)

    Hundal, R.

    1976-01-01

    A cold trap assembly for removing impurities from a liquid metal is described. A hole between the incoming impure liquid metal and purified outgoing liquid metal acts as a continuous bleed means and thus prevents the accumulation of cover gases within the cold trap assembly

  3. Gas-Liquid Precipitation of water dissolved heavy metal ions using hydrogen sulfide gas

    NARCIS (Netherlands)

    Al Tarazi, M.Y.M.

    2004-01-01

    Precipitation of solids promoted by gas-liquid reactions is applied in many industrial processes such as the production of ammonium phosphate, ammonium sulphate, barium carbonate, calcium carbonate, calcium fluoride, ypsum (calcium sulphate), goethite, sodium bicarbonate, strontium carbonate and

  4. Resistance probe for liquid hydrogen

    International Nuclear Information System (INIS)

    Beauval, J.J.

    1959-01-01

    A simple device for determining the level of a liquid in equilibrium with its vapour is described. It makes use of the variation in heat exchange between a filament heated by a current and the atmosphere, on passing from the liquid to the gas. This apparatus is used to measure liquid hydrogen levels in liquefying dewar vessels. (author) [fr

  5. Liquid metal steam generator

    International Nuclear Information System (INIS)

    Wolowodiuk, W.

    1975-01-01

    A liquid metal heated steam generator is described which in the event of a tube failure quickly exhausts out of the steam generator the products of the reaction between the water and the liquid metal. The steam is generated in a plurality of bayonet tubes which are heated by liquid metal flowing over them between an inner cylinder and an outer cylinder. The inner cylinder extends above the level of liquid metal but below the main tube sheet. A central pipe extends down into the inner cylinder with a centrifugal separator between it and the inner cylinder at its lower end and an involute deflector plate above the separator so that the products of a reaction between the liquid metal and the water will be deflected downwardly by the deflector plate and through the separator so that the liquid metal will flow outwardly and away from the central pipe through which the steam and gaseous reaction products are exhausted. (U.S.)

  6. Liquid Metal Transformers

    OpenAIRE

    Sheng, Lei; Zhang, Jie; Liu, Jing

    2014-01-01

    The room temperature liquid metal is quickly emerging as an important functional material in a variety of areas like chip cooling, 3D printing or printed electronics etc. With diverse capabilities in electrical, thermal and flowing behaviors, such fluid owns many intriguing properties that had never been anticipated before. Here, we show a group of unconventional phenomena occurring on the liquid metal objects. Through applying electrical field on the liquid metals immersed in water, a series...

  7. Liquid hydrogen and deuterium targets

    International Nuclear Information System (INIS)

    Bougon, M.; Marquet, M.; Prugne, P.

    1961-01-01

    A description is given of 1) Atmospheric pressure target: liquid hydrogen, 400 mm thickness; thermal insulation: styrofoam; the hydrogen vapors are used to improve the target cooling; Mylar windows. 2) Vacuum target: 12 liter content: hydrogen or deuterium; liquid thickness 400 mm; thermal insulation is afforded by a vacuum vessel and a liquid nitrogen shield. Recovery and liquefaction of deuterium vapors are managed in the vacuum vessel which holds the target. The target emptying system is designed for operating in a few minutes. (author) [fr

  8. Liquid hydrogen: back to basics

    Energy Technology Data Exchange (ETDEWEB)

    Sherif, S.A. [Dept. of Mechanical and Aerospace Engineering, Univ. of Florida, Florida (United States)

    2009-07-01

    'Full text': Liquid hydrogen is primarily used as a rocket fuel and is predestined for supersonic and hypersonic space vehicles to a large extent because it has the lowest boiling point density and the highest specific thrust of any known fuel. Its favorable characteristics include its high heating value per unit mass, its wide ignition range in hydrogen/oxygen or air mixtures, as well as its large flame speed and cooling capacity due to its high specific heat which permits very effective engine cooling and cooling the critical parts of the outer skin. Liquid hydrogen has some other important uses such as in high-energy nuclear physics and bubble chambers. The transport of hydrogen is vastly more economical when it is in liquid form even though cryogenic refrigeration and special Dewar vessels are required. Although liquid hydrogen can provide a lot of advantages, its uses are restricted in part because liquefying hydrogen by existing conventional methods consumes a large amount of energy (around 30% of its heating value). Liquefying 1 kg of hydrogen in a medium-size plant requires 10 to 13 kWh of electric energy. In addition, boil-off losses associated with the storage, transportation, and handling of liquid hydrogen can consume up to 40% of its available combustion energy. It is therefore important to search for ways that can improve the efficiency of the liquefiers and diminish the boil-off losses. This lecture gives an overview of the main issues associated with the production, storage, and handling of liquid hydrogen. Some discussion of promising ways of hydrogen liquefaction will also be presented. (author)

  9. Hydrogen in metals

    International Nuclear Information System (INIS)

    1986-01-01

    The report briefly describes the results of the single projects promoted by the German Council of Research (DFG). The subjects deal with diffusion, effusion, permeation and solubility of hydrogen in metals. They are interesting for many disciplines: metallurgy, physical metallurgy, metal physics, materials testing, welding engineering, chemistry, nuclear physics and solid-state physics. The research projects deal with the following interrelated subjects: solubility of H 2 in steel and effects on embrittlement, influence of H 2 on the fatigue strength of steel as well as the effect of H 2 on welded joints. The studies in solid-state research can be divided into methodological and physico-chemical studies. The methodological studies mainly comprise investigations on the analytical determination of H 2 by means of nuclear-physical reactions (e.g. the 15 N method) and the application of the Moessbauer spectroscopy. Physico-chemical problems are mainly dealt with in studies on interfacial reactions in connection with the absorption of hydrogen and on the diffusion of H 2 in different alloy systems. The properties of materials used for hydrogen storage were the subject of several research projects. 20 contributions were separately recorded for the data bank 'Energy'. (MM) [de

  10. Liquid metals pumping

    International Nuclear Information System (INIS)

    Le Frere, J.P.

    1984-01-01

    Pumps used to pump liquid metals depend on the liquid metal and on the type of application concerned. One deals more particularly with electromagnetic pumps, the main pumps used with mechanical pumps. To pump sodium in the nuclear field, these two types of pumps are used; the pumps of different circuits of Super Phenix are presented and described [fr

  11. Liquid metal monitor

    International Nuclear Information System (INIS)

    Caldwell-Nichols, C.J.; Roach, P.F.

    1982-01-01

    A liquid metal monitor of the by-pass plugging meter kind described in British Patent 1,308,466, is further provided with a pump arranged to oppose flow through a by-pass thereby to provide a constant pressure difference across an orifice and improve the sensitivity of the instrument. The monitor estimates the impurity content in a liquid metal stream. (author)

  12. Microwave plasma for hydrogen production from liquids

    Directory of Open Access Journals (Sweden)

    Czylkowski Dariusz

    2016-06-01

    Full Text Available The hydrogen production by conversion of liquid compounds containing hydrogen was investigated experimentally. The waveguide-supplied metal cylinder-based microwave plasma source (MPS operated at frequency of 915 MHz at atmospheric pressure was used. The decomposition of ethanol, isopropanol and kerosene was performed employing plasma dry reforming process. The liquid was introduced into the plasma in the form of vapour. The amount of vapour ranged from 0.4 to 2.4 kg/h. Carbon dioxide with the flow rate ranged from 1200 to 2700 NL/h was used as a working gas. The absorbed microwave power was up to 6 kW. The effect of absorbed microwave power, liquid composition, liquid flow rate and working gas fl ow rate was analysed. All these parameters have a clear influence on the hydrogen production efficiency, which was described with such parameters as the hydrogen production rate [NL(H2/h] and the energy yield of hydrogen production [NL(H2/kWh]. The best achieved experimental results showed that the hydrogen production rate was up to 1116 NL(H2/h and the energy yield was 223 NL(H2 per kWh of absorbed microwave energy. The results were obtained in the case of isopropanol dry reforming. The presented catalyst-free microwave plasma method can be adapted for hydrogen production not only from ethanol, isopropanol and kerosene, but also from different other liquid compounds containing hydrogen, like gasoline, heavy oils and biofuels.

  13. The chemistry of the liquid alkali metals

    International Nuclear Information System (INIS)

    Addison, C.C.

    1984-01-01

    A study of liquid alkali metals. It encourages comparison with molecular solvents in chapter covering the nature and reactivity of dissolved species, solvation, solubility and electrical conductivity of solutions. It demonstrates lab techniques unique to liquid alkali metals. It discusses large-scale applications from storage batteries to sodium-cooled reactors and future fusion reactors, and associated technological problems. Contents: Some Basic Physical and Chemical Properties; Manipulation of the Liquids; The Chemistry of Purification Methods; Species Formed by Dissolved Elements; Solubilities and Analytical Methods; Alkali Metal Mixtures; Solvation in Liquid Metal; Reactions Between Liquid Alkali Metals and Water; Reactions of Nitrogen with Lithium and the Group II Metals in Liquid Sodium; The Formation, Dissociation and Stability of Heteronuclear Polyatomic Anions; Reactions of the Liquid Alkali Metals and Their Alloys with Simple Alipatic Hydrocarbons; Reactions of the Liquid Alkali Metals with Some Halogen Compounds; Hydrogen, Oxygen and Carbon Meters; Surface Chemistry and Wetting; Corrosion of Transition Metals by the Liquid Alkali Metals; Modern Applications of the Liquid Alkali Metals

  14. Liquid metal pump

    International Nuclear Information System (INIS)

    Pennell, W.E.

    1981-01-01

    A liquid metal pump comprising a shaft support structure which is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft carries an impeller and the support structure carries an impeller cage which is slidably disposed in a diffuser so as to allow complete removal of pump internals for inspection and repair. The diffuser is concentrically supported in the pump housing which also takes up all reaction forces generated by the discharge of the liquid metal from the diffuser, with floating seals arranged between impeller cage and the diffuser. The space between the diffuser and the pump housing permits the incoming liquid to essentially surround the diffuser. (author)

  15. Hydrogen in metals

    CSIR Research Space (South Africa)

    Carter, TJ

    2001-04-01

    Full Text Available .J. Cartera,*, L.A. Cornishb aAdvanced Engineering & Testing Services, MATTEK, CSIR, Private Bag X28, Auckland Park 2006, South Africa bSchool of Process and Materials Engineering, University of the Witwatersrand, Private Bag 3, P.O. WITS 2050, South Africa... are contrasted, and an unusual case study of hydrogen embrittlement of an alloy steel is presented. 7 2001 Published by Elsevier Science Ltd. Keywords: Hydrogen; Hydrogen-assisted cracking; Hydrogen damage; Hydrogen embrittlement 1. Introduction Hydrogen suC128...

  16. Hydrogen permeation through metallic foils

    International Nuclear Information System (INIS)

    Bernardi, M.I.B.; Rodrigues, J.A.

    1987-01-01

    The process of electrolytic permeation of hydrogen through metallic foils is studied. A double electrolytic cell, in glass, in which the two compartments of reaction are separated by a metallic foil to be studied, was built. As direct result, the hydrogen diffusion coefficient in the metal is obtained. The hydrogen diffusion coefficients in the palladium and, in austenitic stainless steels 304 and 304 L, used in the Angra-1 reactor, were obtained. Samples of stainless steels with and without welding, were used. (Author) [pt

  17. Liquid metal pump

    Science.gov (United States)

    Pennell, William E.

    1982-01-01

    The liquid metal pump comprises floating seal rings and attachment of the pump diffuser to the pump bowl for isolating structural deflections from the pump shaft bearings. The seal rings also eliminate precision machining on large assemblies by eliminating the need for a close tolerance fit between the mounting surfaces of the pump and the seals. The liquid metal pump also comprises a shaft support structure that is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft support structure also allows for complete removal of pump internals for inspection and repair.

  18. Liquid metal pump

    International Nuclear Information System (INIS)

    Pennell, W.E.

    1982-01-01

    The liquid metal pump comprises floating seal rings and attachment of the pump diffuser to the pump bowl for isolating structural deflections from the pump shaft bearings. The seal rings also eliminate precision machining on large assemblies by eliminating the need for a close tolerance fit between the mounting surfaces of the pump and the seals. The liquid metal pump also comprises a shaft support structure that is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft support structure also allows for complete removal of pump internals for inspection and repair

  19. Liquid metal level measurement

    International Nuclear Information System (INIS)

    Hale, J.C.; Leyland, K.S.

    1982-01-01

    A liquid metal level indicator is described which can be used to measure, in a stainless steel tank, the level of a nuclear reactor coolant such as sodium. The instrument, which is based on the eddy current induction effect, gives readings over substantially the full depth of the tank and indicates the sense of change of level. (U.K.)

  20. Liquid metal magnetohydrodynamic convertor

    International Nuclear Information System (INIS)

    Aladiev, I.T.; Dzhamardzhashvili, V.A.

    1981-01-01

    This invention relates to the generation of electrical energy by direct conversion from thermal or electrical energy and notably to liquid metal magnetohydrodynamic convertors. The convertor described in this invention can be successfully used as a source of electrical energy for space vessels, for underwater vessels, for aeronautics and for the generation of electrical energy in thermal or atomic power plants. This liquid metal convertor consists of a heat source, a two phase nozzle, a separator, a steam diffuser and a condenser. These elements are connected together hydraulically in series. The condenser is connected hydraulically to a heat source, a liquid diffuser and a magnetohydrodynamic generator. These elements are interconnected hydraulically to the separator and heat source [fr

  1. Metallic hydrogen: The most powerful rocket fuel yet to exist

    Energy Technology Data Exchange (ETDEWEB)

    Silvera, Isaac F [Lyman Laboratory of Physics, Harvard University, Cambridge MA 02138 (United States); Cole, John W, E-mail: silvera@physics.harvard.ed [NASA MSFC, Huntsville, AL 35801 (United States)

    2010-03-01

    Wigner and Huntington first predicted that pressures of order 25 GPa were required for the transition of solid molecular hydrogen to the atomic metallic phase. Later it was predicted that metallic hydrogen might be a metastable material so that it remains metallic when pressure is released. Experimental pressures achieved on hydrogen have been more than an order of magnitude higher than the predicted transition pressure and yet it remains an insulator. We discuss the applications of metastable metallic hydrogen to rocketry. Metastable metallic hydrogen would be a very light-weight, low volume, powerful rocket propellant. One of the characteristics of a propellant is its specific impulse, I{sub sp}. Liquid (molecular) hydrogen-oxygen used in modern rockets has an Isp of {approx}460s; metallic hydrogen has a theoretical I{sub sp} of 1700s. Detailed analysis shows that such a fuel would allow single-stage rockets to enter into orbit or carry economical payloads to the moon. If pure metallic hydrogen is used as a propellant, the reaction chamber temperature is calculated to be greater than 6000 K, too high for currently known rocket engine materials. By diluting metallic hydrogen with liquid hydrogen or water, the reaction temperature can be reduced, yet there is still a significant performance improvement for the diluted mixture.

  2. Use of triphenyl phosphate as risk mitigant for metal amide hydrogen storage materials

    Science.gov (United States)

    Cortes-Concepcion, Jose A.; Anton, Donald L.

    2016-04-26

    A process in a resulting product of the process in which a hydrogen storage metal amide is modified by a ball milling process using an additive of TPP. The resulting product provides for a hydrogen storage metal amide having a coating that renders the hydrogen storage metal amide resistant to air, ambient moisture, and liquid water while improving useful hydrogen storage and release kinetics.

  3. Hydrogen permeability through metals

    International Nuclear Information System (INIS)

    Pisarev, A.A.; Tsvetkov, I.V.; Marenkov, E.D.; Yarko, S.S.

    2011-01-01

    The mechanisms of hydrogen permeability through one-layer and multi-layer membranes are considered. The effect of surface roughness, crystal defects, cracks and pores is described. Mathematical description of the processes is given [ru

  4. Polarized Light from the Sun: Unification of the Corona and Analysis of the Second Solar Spectrum — Further Implications of a Liquid Metallic Hydrogen Solar Model

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2015-07-01

    Full Text Available In order to account for the slight polarization of the continuum towards the limb, propo- nents of the Standard Solar Model (SSM must have recourse to electron or hydrogen- based scattering of light, as no other mechanism is possible in a gaseous Sun. Con- versely, acceptance that the solar body is comprised of condensed matter opens up new avenues in the analysis of this problem, even if the photospheric surface itself is viewed as incapable of emitting polarized light. Thus, the increased disk polarization, from the center to the limb, can be explained by invoking the scattering of light by the at- mosphere above the photosphere. The former is reminiscent of mechanisms which are known to account for the polarization of sunlight in the atmosphere of the Earth. Within the context of the Liquid Metallic Hydrogen Solar Model (LMHSM, molecules and small particles, not electrons or hydrogen atoms as required by the SSM, would primarily act as scattering agents in regions also partially comprised of condensed hy- drogen structures (CHS. In addition, the well-known polarization which characterizes the K-corona would become a sign of emission polarization from an anisotropic source, without the need for scattering. In the LMHSM, the K, F, and T- coronas can be viewed as emissive and reflective manifestations of a single corona l entity adopting a radially anisotropic structure, while slowly cooling with altitude above the photosphere. The presence of “dust particles”, advanced by proponents of the SSM, would no longer be required to explain the F and T-corona, as a single cooling structure would account for the properties of the K, F, and T coronas. At the same time, the polarized “Second Solar Spectrum”, characterized by the dominance of certain elemental or ionic spectral lines and an abundance of molecular lines, could be explained in the LMHSM, by first invoking interface polarization and coordination of these species with condensed matter

  5. Final Report: Metal Perhydrides for Hydrogen Storage

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, J-Y.; Shi, S.; Hackney, S.; Swenson, D.; Hu, Y.

    2011-07-26

    Hydrogen is a promising energy source for the future economy due to its environmental friendliness. One of the important obstacles for the utilization of hydrogen as a fuel source for applications such as fuel cells is the storage of hydrogen. In the infrastructure of the expected hydrogen economy, hydrogen storage is one of the key enabling technologies. Although hydrogen possesses the highest gravimetric energy content (142 KJ/g) of all fuels, its volumetric energy density (8 MJ/L) is very low. It is desired to increase the volumetric energy density of hydrogen in a system to satisfy various applications. Research on hydrogen storage has been pursed for many years. Various storage technologies, including liquefaction, compression, metal hydride, chemical hydride, and adsorption, have been examined. Liquefaction and high pressure compression are not desired due to concerns related to complicated devices, high energy cost and safety. Metal hydrides and chemical hydrides have high gravimetric and volumetric energy densities but encounter issues because high temperature is required for the release of hydrogen, due to the strong bonding of hydrogen in the compounds. Reversibility of hydrogen loading and unloading is another concern. Adsorption of hydrogen on high surface area sorbents such as activated carbon and organic metal frameworks does not have the reversibility problem. But on the other hand, the weak force (primarily the van der Waals force) between hydrogen and the sorbent yields a very small amount of adsorption capacity at ambient temperature. Significant storage capacity can only be achieved at low temperatures such as 77K. The use of liquid nitrogen in a hydrogen storage system is not practical. Perhydrides are proposed as novel hydrogen storage materials that may overcome barriers slowing advances to a hydrogen fuel economy. In conventional hydrides, e.g. metal hydrides, the number of hydrogen atoms equals the total valence of the metal ions. One Li

  6. Container for liquid metal

    International Nuclear Information System (INIS)

    Abe, Yoshihito; Imazu, Takayuki; Ueda, Sabuo; Ueya, Katsumi.

    1980-01-01

    Purpose: To arrange a vapor trapping member of a specific structure at the inlet part of a cylindrical gap formed by the inner peripheral surface of the circular opening of a container and the outer peripheral surface of a rotary plug thereby to prevent ingress of vapor in the upper part of the cylindrical gap for a long period of time. Constitution: A sealing material receiving tray is fitted to the container side of the inlet part of a cylindrical gap, and a partition plate is fitted to the rotary plug side. The tray is filled with a sealing material consisting of a large number of steel balls, mesh wire gages and the like, and the partition plate is placed in the tray thereby to carry out sealing of the container. Liquid metal vapor evaporating from the liquid level of the liquid metal adheres to the sealing material to fill the gap, and therefore ingress of vapor to the upper part of the cylindrical gap is prevented, and there is no possibility of causing seal cutting due to the use for a long period. (Sekiya, K.)

  7. Trace hydrogen extraction from liquid lithium tin alloy

    International Nuclear Information System (INIS)

    Xie Bo; Hu Rui; Xie Shuxian; Weng Kuiping

    2010-01-01

    In order to finish the design of tritium extraction system (TES) of fusion fission hybrid reactor (FFHR) tritium blanket, involving the dynamic mathematical model of liquid metal in contact with a gaseous atmosphere, approximate mathematical equation of tritium in lithium tin alloy was deduced. Moreover, carrying process used for trace hydrogen extraction from liquid lithium tin alloy was investigated with hydrogen being used to simulate tritium in the study. The study results indicate that carrying process is effective way for hydrogen extraction from liquid lithium tin alloy, and the best flow velocity of carrier gas is about 4 L/min under 1 kg alloy temperatures and carrying numbers are the main influencing factors of hydrogen number. Hydrogen extraction efficiency can reach 85% while the alloy sample is treated 6 times at 823 K. (authors)

  8. Water tube liquid metal control

    International Nuclear Information System (INIS)

    Campbell, J.W.E.

    1981-01-01

    An improved heat exchanger for use in liquid metal cooled nuclear power reactors is described in which the heat is transferred between the flow of liquid metal which is to be cooled and a forced flow of liquid which is wholly or partly evaporated. (U.K.)

  9. Storage of hydrogen in metals

    International Nuclear Information System (INIS)

    Wiswall, R.

    1981-01-01

    A review is dedicated to a problem of hydrogen storage as fuel of future, that can be used under various conditions, is easily obtained with the help of other types of energy and can be transformed into them. Data on reversible metal-hydrogen systems, where hydrogen can be obtained by the way of reaction of thermal decomposition are presented. Pressure-temperature-content diagrams, information on concrete Pd-H, TiFe-H, V-N systems are presented and analyzed from the point of view of thermodynamics. A table with thermodynamical characteristics of several hydrides is presented. The majority of known solid hydrides in relation to their use for hydrogen storage are characterized. The review includes information on real or supposed uses in concrete systems: in fuel cells, for levelling of loading of electric plants, in automobile engines, in hydride engines, for heat storage [ru

  10. Permeation barrier for lightweight liquid hydrogen tanks

    Energy Technology Data Exchange (ETDEWEB)

    Schultheiss, D.

    2007-04-16

    For the future usage of hydrogen as an automotive fuel, its on-board storage is crucial. One approach is the storage of liquid hydrogen (LH2, 20 K) in double-walled, vacuum insulated tanks. The introduction of carbon fiber reinforced plastics (CFRP) as structural material enables a high potential of reducing the weight in comparison to the state-of-the-art stainless steel tanks. The generally high permeability of hydrogen through plastics, however, can lead to long-term degradation of the insulating vacuum. The derived objective of this dissertation was to find and apply an adequate permeation barrier (liner) on CFRP. The investigated liners were either foils adhered on CFRP specimens or coatings deposited on CFRP specimens. The coatings were produced by means of thermal spraying, metal plating or physical vapor deposition (PVD). The materials of the liners included Al, Au, Cu, Ni and Sn as well as stainless steel and diamond-like carbon. The produced liners were tested for their permeation behavior, thermal shock resistance and adherence to the CFRP substrate. Additionally, SEM micrographs were used to characterize and qualify the liners. The foils, although being a good permeation barrier, adhered weakly to the substrate. Furthermore, leak-free joining of foil segments is a challenge still to be solved. The metal plating liners exhibited the best properties. For instance, no permeation could be detected through a 50 {mu}m thick Cu coating within the accuracy of the measuring apparatus. This corresponds to a reduction of the permeation gas flow by more than factor 7400 compared to uncoated CFRP. In addition, the metal platings revealed a high adherence and thermal shock resistance. The coatings produced by means of thermal spraying and PVD did not show a sufficient permeation barrier effect. After having investigated the specimens, a 170 liter CFRP tank was fully coated with 50 {mu}m Cu by means of metal plating. (orig.)

  11. Vapor trap for liquid metal

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T

    1968-05-22

    In a pipe system which transfers liquid metal, inert gas (cover gas) is packed above the surface of the liquid metal to prevent oxidization of the liquid. If the metal vapor is contained in such cover gas, the circulating system of the cover gas is blocked due to condensation of liquid metal inside the system. The present invention relates to an improvement in vapor trap to remove the metal vapor from the cover gas. The trap consists of a cylindrical outer body, an inlet nozzle which is deeply inserted inside the outer body and has a number of holes to inject the cove gas into the body, metal mesh or steel wool which covers the exterior of the nozzle and on which the condensation of the metal gas takes place, and a heater wire hich is wound around the nozzle to prevent condensation of the metal vapor at the inner peripheral side of the mesh.

  12. Comments on liquid hydrogen absorbers for MICE

    International Nuclear Information System (INIS)

    Green, Michael A.

    2003-01-01

    This report describes the heat transfer problems associated with a liquid hydrogen absorber for the MICE experiment. This report describes a technique for modeling heat transfer from the outside world, to the absorber case and in its vacuum vessel, to the hydrogen and then into helium gas at 14 K. Also presented are the equation for free convection cooling of the liquid hydrogen in the absorber

  13. Liquid metal cooled nuclear reactor

    International Nuclear Information System (INIS)

    Leigh, K.M.

    1980-01-01

    A liquid metal cooled nuclear reactor is described, wherein coolant is arranged to be flowed upwardly through a fuel assembly and having one or more baffles located above the coolant exit of the fuel assembly, the baffles being arranged so as to convert the upwardly directed motion of liquid metal coolant leaving the fuel assembly into a substantially horizontal motion. (author)

  14. Cryogenic system for liquid hydrogen polarimeter

    International Nuclear Information System (INIS)

    Kitami, T.; Chiba, M.; Hirabayashi, H.; Ishii, T.; Kato, S.

    1979-01-01

    A cryogenic system has been constructed for a liquid hydrogen polarimeter in order to measure polarization of high energy proton at the 1.3 GeV electron synchrotron of Institute for Nuclear Study, University of Tokyo. The system principally consists of a cryogenerator with a cryogenic transfer line, a liquid hydrogen cryostat, and a 14.5 l target container of thin aluminum alloy where liquid hydrogen is served for the experiment. The refrigeration capacity is about 54 W at 20.4 K without a target container. (author)

  15. LIQUID METAL COMPOSITIONS CONTAINING URANIUM

    Science.gov (United States)

    Teitel, R.J.

    1959-04-21

    Liquid metal compositions containing a solid uranium compound dispersed therein is described. Uranium combines with tin to form the intermetallic compound USn/sub 3/. It has been found that this compound may be incorporated into a liquid bath containing bismuth and lead-bismuth components, if a relatively small percentage of tin is also included in the bath. The composition has a low thermal neutron cross section which makes it suitable for use in a liquid metal fueled nuclear reactor.

  16. High temperature equation of state of metallic hydrogen

    International Nuclear Information System (INIS)

    Shvets, V. T.

    2007-01-01

    The equation of state of liquid metallic hydrogen is solved numerically. Investigations are carried out at temperatures from 3000 to 20 000 K and densities from 0.2 to 3 mol/cm 3 , which correspond both to the experimental conditions under which metallic hydrogen is produced on earth and the conditions in the cores of giant planets of the solar system such as Jupiter and Saturn. It is assumed that hydrogen is in an atomic state and all its electrons are collectivized. Perturbation theory in the electron-proton interaction is applied to determine the thermodynamic potentials of metallic hydrogen. The electron subsystem is considered in the randomphase approximation with regard to the exchange interaction and the correlation of electrons in the local-field approximation. The proton-proton interaction is taken into account in the hard-spheres approximation. The thermodynamic characteristics of metallic hydrogen are calculated with regard to the zero-, second-, and third-order perturbation theory terms. The third-order term proves to be rather essential at moderately high temperatures and densities, although it is much smaller than the second-order term. The thermodynamic potentials of metallic hydrogen are monotonically increasing functions of density and temperature. The values of pressure for the temperatures and pressures that are characteristic of the conditions under which metallic hydrogen is produced on earth coincide with the corresponding values reported by the discoverers of metallic hydrogen to a high degree of accuracy. The temperature and density ranges are found in which there exists a liquid phase of metallic hydrogen

  17. Pad B Liquid Hydrogen Storage Tank

    Science.gov (United States)

    Hall, Felicia

    2007-01-01

    Kennedy Space Center is home to two liquid hydrogen storage tanks, one at each launch pad of Launch Complex 39. The liquid hydrogen storage tank at Launch Pad B has a significantly higher boil off rate that the liquid hydrogen storage tank at Launch Pad A. This research looks at various calculations concerning the at Launch Pad B in an attempt to develop a solution to the excess boil off rate. We will look at Perlite levels inside the tank, Boil off rates, conductive heat transfer, and radiant heat transfer through the tank. As a conclusion to the research, we will model the effects of placing an external insulation to the tank in order to reduce the boil off rate and increase the economic efficiency of the liquid hydrogen storage tanks.

  18. Pair potentials in liquid metals

    International Nuclear Information System (INIS)

    Faber, T.E.

    1980-01-01

    The argument which justifies the use of a pair potential to describe the structure-dependent term in the energy of liquid metals is briefly reviewed. Because there is an additional term in the energy which depends upon volume rather than structure, and because the pair potential itself is volume-dependent, the relationship between pair potential and observable properties such as pressure, bulk modulus and pair distribution function is more complicated for liquid metals than it is for molecular liquids. Perhaps for this reason, the agreement between pair potentials inferred from observable properties and pair potentials calculated by means of pseudo-potential theory is still far from complete. The pair potential concept is applicable only to simple liquid metals, in which the electron-ion interaction is weak. No attempt is made to discuss liquid transition and rare-earth metals, which are not simple in this sense. (author)

  19. Hydrogen bonding in ionic liquids.

    Science.gov (United States)

    Hunt, Patricia A; Ashworth, Claire R; Matthews, Richard P

    2015-03-07

    Ionic liquids (IL) and hydrogen bonding (H-bonding) are two diverse fields for which there is a developing recognition of significant overlap. Doubly ionic H-bonds occur when a H-bond forms between a cation and anion, and are a key feature of ILs. Doubly ionic H-bonds represent a wide area of H-bonding which has yet to be fully recognised, characterised or explored. H-bonds in ILs (both protic and aprotic) are bifurcated and chelating, and unlike many molecular liquids a significant variety of distinct H-bonds are formed between different types and numbers of donor and acceptor sites within a given IL. Traditional more neutral H-bonds can also be formed in functionalised ILs, adding a further level of complexity. Ab initio computed parameters; association energies, partial charges, density descriptors as encompassed by the QTAIM methodology (ρBCP), qualitative molecular orbital theory and NBO analysis provide established and robust mechanisms for understanding and interpreting traditional neutral and ionic H-bonds. In this review the applicability and extension of these parameters to describe and quantify the doubly ionic H-bond has been explored. Estimating the H-bonding energy is difficult because at a fundamental level the H-bond and ionic interaction are coupled. The NBO and QTAIM methodologies, unlike the total energy, are local descriptors and therefore can be used to directly compare neutral, ionic and doubly ionic H-bonds. The charged nature of the ions influences the ionic characteristics of the H-bond and vice versa, in addition the close association of the ions leads to enhanced orbital overlap and covalent contributions. The charge on the ions raises the energy of the Ylp and lowers the energy of the X-H σ* NBOs resulting in greater charge transfer, strengthening the H-bond. Using this range of parameters and comparing doubly ionic H-bonds to more traditional neutral and ionic H-bonds it is clear that doubly ionic H-bonds cover the full range of weak

  20. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere II. Continuous Emission and Condensed Matter Within the Corona

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-07-01

    Full Text Available The K-corona, a significant portion of the solar atmosphere, displays a continuous spectrum which closely parallels photospheric emission, though without the presence of overlying Fraunhofer lines. The E-corona exists in the same region and is characterized by weak emission lines from highly ionized atoms. For instance, the famous green emission line from coronium (FeXIV is part of the E-corona. The F-corona exists beyond the K/E-corona and, like the photospheric spectrum, is characterized by Fraunhofer lines. The F-corona represents photospheric light scattered by dust particles in the interplanetary medium. Within the gaseous models of the Sun, the K-corona is viewed as photospheric radiation which has been scattered by relativistic electrons. This scattering is thought to broaden the Fraunhofer lines of the solar spectrum such that they can no longer be detected in the K-corona. Thus, the gaseous models of the Sun account for the appearance of the K-corona by distorting photospheric light, since they are unable to have recourse to condensed matter to directly produce such radiation. Conversely, it is now advanced that the continuous emission of the K-corona and associated emission lines from the E-corona must be interpreted as manifestations of the same phenomenon: condensed matter exists in the corona. It is well-known that the Sun expels large amounts of material from its surface in the form of flares and coronal mass ejections. Given a liquid metallic hydrogen model of the Sun, it is logical to assume that such matter, which exists in the condensed state on the solar surface, continues to manifest its nature once expelled into the corona. Therefore, the continuous spectrum of the K-corona provides the twenty-seventh line of evidence that the Sun is composed of condensed matter.

  1. Actively convected liquid metal divertor

    International Nuclear Information System (INIS)

    Shimada, Michiya; Hirooka, Yoshi

    2014-01-01

    The use of actively convected liquid metals with j × B force is proposed to facilitate heat handling by the divertor, a challenging issue associated with magnetic fusion experiments such as ITER. This issue will be aggravated even more for DEMO and power reactors because the divertor heat load will be significantly higher and yet the use of copper would not be allowed as the heat sink material. Instead, reduced activation ferritic/martensitic steel alloys with heat conductivities substantially lower than that of copper, will be used as the structural materials. The present proposal is to fill the lower part of the vacuum vessel with liquid metals with relatively low melting points and low chemical activities including Ga and Sn. The divertor modules, equipped with electrodes and cooling tubes, are immersed in the liquid metal. The electrode, placed in the middle of the liquid metal, can be biased positively or negatively with respect to the module. The j × B force due to the current between the electrode and the module provides a rotating motion for the liquid metal around the electrodes. The rise in liquid temperature at the separatrix hit point can be maintained at acceptable levels from the operation point of view. As the rotation speed increases, the current in the liquid metal is expected to decrease due to the v × B electromotive force. This rotating motion in the poloidal plane will reduce the divertor heat load significantly. Another important benefit of the convected liquid metal divertor is the fast recovery from unmitigated disruptions. Also, the liquid metal divertor concept eliminates the erosion problem. (letter)

  2. Liquid metal heat transfer issues

    International Nuclear Information System (INIS)

    Hoffman, H.W.; Yoder, G.L.

    1984-01-01

    An alkali liquid metal cooled nuclear reactor coupled with an alkali metal Rankine cycle provides a practicable option for space systems/missions requiring power in the 1 to 100 MW(e) range. Thermal issues relative to the use of alkali liquid metals for this purpose are identified as these result from the nature of the alkali metal fluid itself, from uncertainties in the available heat transfer correlations, and from design and performance requirements for system components operating in the earth orbital microgravity environment. It is noted that, while these issues require further attention to achieve optimum system performance, none are of such magnitude as to invalidate this particular space power concept

  3. Thermal properties of hydrogenated liquid natural rubber

    Science.gov (United States)

    Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

    2015-09-01

    Natural rubber (NR) was modified to form liquid natural rubber (LNR) via photooxidative degradation. Hydrogenated liquid natural rubber (HLNR) was synthesized by using diimide as source of hydrogen which the diimide is produced by thermolysis of p-toluenesulfonyl hydrazide (TSH). The structure of HLNR was characterized by determining the changes of main peaks in Fourier Transform infrared and nuclear magnetic resonance spectra after hydrogenation. Thermogravimetric analysis showed that the HLNR had higher decomposition temperature compared to LNR and the decomposition temperature is directly proportional to the percentage of conversion.

  4. Thermal properties of hydrogenated liquid natural rubber

    International Nuclear Information System (INIS)

    Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

    2015-01-01

    Natural rubber (NR) was modified to form liquid natural rubber (LNR) via photooxidative degradation. Hydrogenated liquid natural rubber (HLNR) was synthesized by using diimide as source of hydrogen which the diimide is produced by thermolysis of p-toluenesulfonyl hydrazide (TSH). The structure of HLNR was characterized by determining the changes of main peaks in Fourier Transform infrared and nuclear magnetic resonance spectra after hydrogenation. Thermogravimetric analysis showed that the HLNR had higher decomposition temperature compared to LNR and the decomposition temperature is directly proportional to the percentage of conversion

  5. Thermal properties of hydrogenated liquid natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2015-09-25

    Natural rubber (NR) was modified to form liquid natural rubber (LNR) via photooxidative degradation. Hydrogenated liquid natural rubber (HLNR) was synthesized by using diimide as source of hydrogen which the diimide is produced by thermolysis of p-toluenesulfonyl hydrazide (TSH). The structure of HLNR was characterized by determining the changes of main peaks in Fourier Transform infrared and nuclear magnetic resonance spectra after hydrogenation. Thermogravimetric analysis showed that the HLNR had higher decomposition temperature compared to LNR and the decomposition temperature is directly proportional to the percentage of conversion.

  6. Hydrogen meter for service in liquid sodium

    International Nuclear Information System (INIS)

    McCown, J.J.

    1983-11-01

    This standard establishes the requirements for the design, materials, fabrication, quality assurance, examination, and acceptance testing of a hydrogen meter and auxiliary equipment for use in radioactive or nonradioactive liquid sodium service. The meter shall provide a continuous and accurate indication of the hydrogen impurity concentration over the range 0.03 to 10 ppM hydrogen in sodium at temperatures between 800 and 1000 0 F (427 and 538 0 C). The meter may also be used to rapidly monitor changes in hydrogen concentration, over the same concentration range, and, therefore can be used as a sensor for sodium-water reactions in LMFBR steam generators

  7. FLIT: Flowing LIquid metal Torus

    Science.gov (United States)

    Kolemen, Egemen; Majeski, Richard; Maingi, Rajesh; Hvasta, Michael

    2017-10-01

    The design and construction of FLIT, Flowing LIquid Torus, at PPPL is presented. FLIT focuses on a liquid metal divertor system suitable for implementation and testing in present-day fusion systems, such as NSTX-U. It is designed as a proof-of-concept fast-flowing liquid metal divertor that can handle heat flux of 10 MW/m2 without an additional cooling system. The 72 cm wide by 107 cm tall torus system consisting of 12 rectangular coils that give 1 Tesla magnetic field in the center and it can operate for greater than 10 seconds at this field. Initially, 30 gallons Galinstan (Ga-In-Sn) will be recirculated using 6 jxB pumps and flow velocities of up to 10 m/s will be achieved on the fully annular divertor plate. FLIT is designed as a flexible machine that will allow experimental testing of various liquid metal injection techniques, study of flow instabilities, and their control in order to prove the feasibility of liquid metal divertor concept for fusion reactors. FLIT: Flowing LIquid metal Torus. This work is supported by the US DOE Contract No. DE-AC02-09CH11466.

  8. Development of Automotive Liquid Hydrogen Storage Systems

    Science.gov (United States)

    Krainz, G.; Bartlok, G.; Bodner, P.; Casapicola, P.; Doeller, Ch.; Hofmeister, F.; Neubacher, E.; Zieger, A.

    2004-06-01

    Liquid hydrogen (LH2) takes up less storage volume than gas but requires cryogenic vessels. State-of-the-art applications for passenger vehicles consist of double-wall cylindrical tanks that hold a hydrogen storage mass of up to 10 kg. The preferred shell material of the tanks is stainless steel, since it is very resistant against hydrogen brittleness and shows negligible hydrogen permeation. Therefore, the weight of the whole tank system including valves and heat exchanger is more than 100 kg. The space between the inner and outer vessel is mainly used for thermal super-insulation purposes. Several layers of insulation foils and high vacuums of 10-3 Pa reduce the heat entry. The support structures, which keep the inner tank in position to the outer tank, are made of materials with low thermal conductivity, e.g. glass or carbon fiber reinforced plastics. The remaining heat in-leak leads to a boil-off rate of 1 to 3 percent per day. Active cooling systems to increase the stand-by time before evaporation losses occur are being studied. Currently, the production of several liquid hydrogen tanks that fulfill the draft of regulations of the European Integrated Hydrogen Project (EIHP) is being prepared. New concepts of lightweight liquid hydrogen storage tanks will be investigated.

  9. Forces in Liquid Metal Contacts

    DEFF Research Database (Denmark)

    Duggen, Lars; Mátéfi-Tempfli, Stefan

    2014-01-01

    Using rather well known theory about capillary bridges between two electrodes we calculate the tensile force that can be applied to liquid metal contacts in the micrometer regime. Assuming circular symmetry, full wetting of the electrodes, and neglecting gravity, we present a brief review of the ...... of the necessary theory and find numerically the forces to be in the 100μN range for liquid metals as mercury and liquid Gallium suspended between electrodes of 20μm radius.......Using rather well known theory about capillary bridges between two electrodes we calculate the tensile force that can be applied to liquid metal contacts in the micrometer regime. Assuming circular symmetry, full wetting of the electrodes, and neglecting gravity, we present a brief review...

  10. Modeling leaks from liquid hydrogen storage systems.

    Energy Technology Data Exchange (ETDEWEB)

    Winters, William Stanley, Jr.

    2009-01-01

    This report documents a series of models for describing intended and unintended discharges from liquid hydrogen storage systems. Typically these systems store hydrogen in the saturated state at approximately five to ten atmospheres. Some of models discussed here are equilibrium-based models that make use of the NIST thermodynamic models to specify the states of multiphase hydrogen and air-hydrogen mixtures. Two types of discharges are considered: slow leaks where hydrogen enters the ambient at atmospheric pressure and fast leaks where the hydrogen flow is usually choked and expands into the ambient through an underexpanded jet. In order to avoid the complexities of supersonic flow, a single Mach disk model is proposed for fast leaks that are choked. The velocity and state of hydrogen downstream of the Mach disk leads to a more tractable subsonic boundary condition. However, the hydrogen temperature exiting all leaks (fast or slow, from saturated liquid or saturated vapor) is approximately 20.4 K. At these temperatures, any entrained air would likely condense or even freeze leading to an air-hydrogen mixture that cannot be characterized by the REFPROP subroutines. For this reason a plug flow entrainment model is proposed to treat a short zone of initial entrainment and heating. The model predicts the quantity of entrained air required to bring the air-hydrogen mixture to a temperature of approximately 65 K at one atmosphere. At this temperature the mixture can be treated as a mixture of ideal gases and is much more amenable to modeling with Gaussian entrainment models and CFD codes. A Gaussian entrainment model is formulated to predict the trajectory and properties of a cold hydrogen jet leaking into ambient air. The model shows that similarity between two jets depends on the densimetric Froude number, density ratio and initial hydrogen concentration.

  11. Alkaline ionic liquids applied in supported ionic liquid catalyst for selective hydrogenation of citral to citronellal

    Directory of Open Access Journals (Sweden)

    Eero eSalminen

    2014-02-01

    Full Text Available The challenge in preparation of ionic liquids containing a strong alkaline anion is to identify a suitable cation which can tolerate the harsh conditions induced by the anion. In this study, a commercial quaternary ammonium compound (quat benzalkonium [ADBA] (alkyldimethylbenzylammonium was used as a cation in the synthesis of different alkaline ionic liquids. In fact, the precursor, benzalkonium chloride, is a mixture of alkyldimethylbenzylammonium chlorides of various alkyl chain lengths and is commonly used in the formulation of various antiseptic products. The prepared ionic liquids were utilized as Supported Ionic Liquid Catalysts (SILCAs. Typically, a SILCA contains metal nanoparticles, enzymes or metal complexes in an ionic liquid layer which is immobilized on a solid carrier material such as an active carbon cloth (ACC. The catalysts were applied in the selective hydrogenation of citral to citronellal which is an important perfumery chemical. Interestingly, 70 % molar yield towards citronellal was achieved over a catalyst containing the alkaline ionic liquid benzalkonium methoxide.

  12. Alkaline ionic liquids applied in supported ionic liquid catalyst for selective hydrogenation of citral to citronellal

    Science.gov (United States)

    Salminen, Eero; Virtanen, Pasi; Mikkola, Jyri-Pekka

    2014-01-01

    The challenge in preparation of ionic liquids containing a strong alkaline anion is to identify a suitable cation which can tolerate the harsh conditions induced by the anion. In this study, a commercial quaternary ammonium compound (quat) benzalkonium [ADBA] (alkyldimethylbenzylammonium) was used as a cation in the synthesis of different alkaline ionic liquids. In fact, the precursor, benzalkonium chloride, is a mixture of alkyldimethylbenzylammonium chlorides of various alkyl chain lengths and is commonly used in the formulation of various antiseptic products. The prepared ionic liquids were utilized as Supported Ionic Liquid Catalysts (SILCAs). Typically, a SILCA contains metal nanoparticles, enzymes, or metal complexes in an ionic liquid layer which is immobilized on a solid carrier material such as an active carbon cloth (ACC). The catalysts were applied in the selective hydrogenation of citral to citronellal which is an important perfumery chemical. Interestingly, 70% molar yield toward citronellal was achieved over a catalyst containing the alkaline ionic liquid benzalkonium methoxide. PMID:24790972

  13. Metal hydrides for hydrogen storage in nickel hydrogen batteries

    International Nuclear Information System (INIS)

    Bittner, H.F.; Badcock, C.C.; Quinzio, M.V.

    1984-01-01

    Metal hydride hydrogen storage in nickel hydrogen (Ni/H 2 ) batteries has been shown to increase battery energy density and improve battery heat management capabilities. However the properties of metal hydrides in a Ni/H 2 battery environment, which contains water vapor and oxygen in addition to the hydrogen, have not been well characterized. This work evaluates the use of hydrides in Ni/H 2 batteries by fundamental characterization of metal hydride properties in a Ni/H 2 cell environment. Hydrogen sorption properties of various hydrides have been measured in a Ni/H 2 cell environment. Results of detailed thermodynamic and kinetic studies of hydrogen sorption in LaNi 5 in a Ni/H 2 cell environment are presented. Long-term cycling studies indicate that degradation of the hydride can be minimized by cycling between certain pressure limits. A model describing the mechanism of hydride degradation is presented

  14. Magnetostriction of Liquid Metals

    Science.gov (United States)

    Bhandia, Rishi; Cooley, Jason C.; Imhoff, Seth D.

    The study of magnetic field-driven microstructural effects is in its infancy, but results have been promising. Previous work showed that these effects are easily observable in some systems, suggesting that magnetic fields could be used to control and engineer various micro-structural properties. The energy scales for crystallite rotation in the liquid and on the viscosity of the melt are known. However, the fundamental energy scale of the magnetic field interaction with the liquid and solid near the melting point is not. In this talk, we present magnetostriction data on liquid elements and alloys that will help us understand the energy scale of these processes and develop a theoretical understanding of solidification in magnetic fields.

  15. Process for hydrogen isotope exchange and concentration between liquid water and hydrogen gas and catalyst assembly therefor

    International Nuclear Information System (INIS)

    Stevens, W.H.

    1975-01-01

    A bithermal, catalytic, hydrogen isotope exchange process between liquid water and hydrogen gas to effect concentration of the deuterium isotope of hydrogen is described. Liquid water and hydrogen gas are contacted with one another and with at least one catalytically active metal selected from Group VIII of the Periodic Table; the catalyst body has a water repellent, gas and water vapor permeable, organic polymer or resin coating, preferably a fluorinated olefin polymer or silicone resin coating, so that the isotope exchange takes place by two simultaneously occurring, and closely coupled in space, steps and concentration is effected by operating two interconnected sections containing catalyst at different temperatures. (U.S.)

  16. H2T liquid hydrogen delivery system

    International Nuclear Information System (INIS)

    Roy, S.

    2002-01-01

    This Power Point presentation provides a preliminary evaluation of the cost of delivering liquid hydrogen produced in Quebec to hydrogen fuelled cars in Germany. The presentation describes the chain of events regarding liquid hydrogen delivery, beginning with the production of hydrogen from an initial source of hydro power. Water passes through an electrolyzer where hydrogen is liquefied and then placed into a container which is transported to market via truck, rail or tanker. Once transported, the hydrogen fuel is made available for consumers at refueling stations. The paper lists the costs related to transportation with reference to safety rules, pure transportation costs, leasing fees for the containers, and permission of customs duties for the import of hydrogen and export of empty containers between Quebec and Germany. A graph depicting a typical refueling station in Germany and the refueling events per hour was presented. For safety reasons, refueling is performed by a refueling robot. A blueprint of safety and protection distances at a refueling station was also presented. tabs., figs

  17. Electrokinetic Hydrogen Generation from Liquid WaterMicrojets

    Energy Technology Data Exchange (ETDEWEB)

    Duffin, Andrew M.; Saykally, Richard J.

    2007-05-31

    We describe a method for generating molecular hydrogen directly from the charge separation effected via rapid flow of liquid water through a metal orifice, wherein the input energy is the hydrostatic pressure times the volume flow rate. Both electrokinetic currents and hydrogen production rates are shown to follow simple equations derived from the overlap of the fluid velocity gradient and the anisotropic charge distribution resulting from selective adsorption of hydroxide ions to the nozzle surface. Pressure-driven fluid flow shears away the charge balancing hydronium ions from the diffuse double layer and carries them out of the aperture. Downstream neutralization of the excess protons at a grounded target electrode produces gaseous hydrogen molecules. The hydrogen production efficiency is currently very low (ca. 10-6) for a single cylindrical jet, but can be improved with design changes.

  18. Liquid hydrogen production via hydrogen sulfide methane reformation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Cunping; T-Raissi, Ali [University of Central Florida, Florida Solar Energy Center, 1769 Clearlake Road, Cocoa, FL 32922 (United States)

    2008-01-03

    Hydrogen sulfide (H{sub 2}S) methane (CH{sub 4}) reformation (H{sub 2}SMR) (2H{sub 2}S + CH{sub 4} = CS{sub 2} + 4H{sub 2}) is a potentially viable process for the removal of H{sub 2}S from sour natural gas resources or other methane containing gases. Unlike steam methane reformation that generates carbon dioxide as a by-product, H{sub 2}SMR produces carbon disulfide (CS{sub 2}), a liquid under ambient temperature and pressure - a commodity chemical that is also a feedstock for the synthesis of sulfuric acid. Pinch point analyses for H{sub 2}SMR were conducted to determine the reaction conditions necessary for no carbon lay down to occur. Calculations showed that to prevent solid carbon formation, low inlet CH{sub 4} to H{sub 2}S ratios are needed. In this paper, we analyze H{sub 2}SMR with either a cryogenic process or a membrane separation operation for production of either liquid or gaseous hydrogen. Of the three H{sub 2}SMR hydrogen production flowsheets analyzed, direct liquid hydrogen generation has higher first and second law efficiencies of exceeding 80% and 50%, respectively. (author)

  19. Liquid hydrogen production via hydrogen sulfide methane reformation

    Science.gov (United States)

    Huang, Cunping; T-Raissi, Ali

    Hydrogen sulfide (H 2S) methane (CH 4) reformation (H 2SMR) (2H 2S + CH 4 = CS 2 + 4H 2) is a potentially viable process for the removal of H 2S from sour natural gas resources or other methane containing gases. Unlike steam methane reformation that generates carbon dioxide as a by-product, H 2SMR produces carbon disulfide (CS 2), a liquid under ambient temperature and pressure-a commodity chemical that is also a feedstock for the synthesis of sulfuric acid. Pinch point analyses for H 2SMR were conducted to determine the reaction conditions necessary for no carbon lay down to occur. Calculations showed that to prevent solid carbon formation, low inlet CH 4 to H 2S ratios are needed. In this paper, we analyze H 2SMR with either a cryogenic process or a membrane separation operation for production of either liquid or gaseous hydrogen. Of the three H 2SMR hydrogen production flowsheets analyzed, direct liquid hydrogen generation has higher first and second law efficiencies of exceeding 80% and 50%, respectively.

  20. Study of liquid hydrogen and liquid deuterium cold neutron sources

    International Nuclear Information System (INIS)

    Harig, H.D.

    1969-01-01

    In view of the plant of the cold neutron source for a high flux reactor (maximal thermal flux of about 10 15 n/cm 2 s) an experimental study of several cold sources of liquid hydrogen and liquid deuterium has been made in a low power reactor (100 kW, about 10 12 n/cm 2 s). We have investigated: -cold neutron sources of liquid hydrogen shaped as annular layers of different thickness. Normal liquid hydrogen was used as well as hydrogen with a high para-percentage. -Cold neutron sources of liquid deuterium in cylinders of 18 and 38 cm diameter. In this case the sources could be placed into different positions to the reactor core within the heavy water reflector. This report gives a general description of the experimental device and deals more detailed with the design of the cryogenic systems. Then, the measured results are communicated, interpreted and finally compared with those of a theoretical study about the same cold moderators which have been the matter of the experimental investigation. (authors) [fr

  1. Liquid metal cooled nuclear reactor

    International Nuclear Information System (INIS)

    Guidez, Joel; Jarriand, Paul.

    1975-01-01

    The invention concerns a fast neutron nuclear reactor cooled by a liquid metal driven through by a primary pump of the vertical drive shaft type fitted at its lower end with a blade wheel. To each pump is associated an exchanger, annular in shape, fitted with a central bore through which passes the vertical drive shaft of the pump, its wheel being mounted under the exchanger. A collector placed under the wheel comprises an open upward suction bell for the liquid metal. A hydrostatic bearing is located above the wheel to guide the drive shaft and a non detachable diffuser into which at least one delivery pipe gives, envelopes the wheel [fr

  2. Liquid Hydrogen Consumption During Space Shuttle Program

    Science.gov (United States)

    Partridge, Jonathan K.

    2011-01-01

    This slide presentation reviews the issue of liquid hydrogen consumption and the points of its loss in prior to the shuttle launch. It traces the movement of the fuel from the purchase to the on-board quantity and the loss that results in 54.6 of the purchased quantity being on board the Shuttle.

  3. Metal ammine complexes for hydrogen storage

    DEFF Research Database (Denmark)

    Christensen, Claus H.; Sørensen, Rasmus Zink; Johannessen, Tue

    2005-01-01

    The hopes of using hydrogen as an energy carrier are severely dampened by the fact that there is still no safe, high-density method available for storing hydrogen. We investigate the possibility of using metal ammine complexes as a solid form of hydrogen storage. Using Mg(NH3)(6)Cl-2 as the example......, we show that it can store 9.1% hydrogen by weight in the form of ammonia. The storage is completely reversible, and by combining it with an ammonia decomposition catalyst, hydrogen can be delivered at temperatures below 620 K....

  4. Hydrogen production from glucose in ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Assenbaum, D.W.; Taccardi, N.; Berger, M.E.M.; Boesmann, A.; Enzenberger, F.; Woelfel, R.; Wasserscheid, P. [Erlangen-Nuernberg Univ. (Germany). Lehrstuhl fuer chemische Reaktionstechnik

    2010-07-01

    technologies suffer from the fact that the overall reaction rates are often restricted by mass and heat transport problems. Lastly, there are severe limitations concerning the feedstock selection as for some important substrates, such as e.g. glucose, the process can only be operated in very diluted systems to avoid rapid tar formation [22,23,24]. In this contribution we describe for the first time a catalytic reaction system producing hydrogen from glucose in astonishingly high selectivities using a single reaction step under very mild conditions. The catalytic reaction system is characterized by its homogeneous nature and comprises a Ru-complex catalyst dissolved and stabilized in an ionic liquid medium. Ionic liquids are salts of melting points below 100 C [25]. These liquid materials have attracted much interest in the last decade as solvents for catalytic reactions [26] and separation technologies (extraction, distillation) [27,28,29,30,31,32]. Besides, these liquids have found industrial applications as process fluids for mechanic [33] and electrochemical applications [34]. Finally, from the pioneering work of Rogers and co-workers, it is known that ionic liquids are able to dissolve significant amounts of water-insoluble biopolymers (such as e.g. cellulose and chitin)[35] and even complex biopolymer mixtures, such as e.g. wood, have been completely dissolved in some ionic liquids [36]. In our specific application, the role of the ionic liquid is threefold: a) the ionic liquid dissolves the carbohydrate starting material thus expanding the range of applicable carbohydrate to water insoluble polymers; b) the ionic liquid provides a medium to dissolve and stabilize the catalyst; c) the ionic liquid dissolves hydrogen at a very low level, so inhibiting any possible collateral hydrogen-consuming process (detailed investigation of the hydrogen solubility in ionic liquids have been reported by e.g. Brennecke and coworkers [37]). (orig.)

  5. Liquid Hydrogen Sensor Considerations for Space Exploration

    Science.gov (United States)

    Moran, Matthew E.

    2006-01-01

    The on-orbit management of liquid hydrogen planned for the return to the moon will introduce new considerations not encountered in previous missions. This paper identifies critical liquid hydrogen sensing needs from the perspective of reliable on-orbit cryogenic fluid management, and contrasts the fundamental differences in fluid and thermodynamic behavior for ground-based versus on-orbit conditions. Opportunities for advanced sensor development and implementation are explored in the context of critical Exploration Architecture operations such as on-orbit storage, docking, and trans-lunar injection burn. Key sensing needs relative to these operations are also examined, including: liquid/vapor detection, thermodynamic condition monitoring, mass gauging, and leak detection. Finally, operational aspects of an integrated system health management approach are discussed to highlight the potential impact on mission success.

  6. Towards hydrogen metallization: an Ab initio approach

    International Nuclear Information System (INIS)

    Bernard, St.

    1998-01-01

    The quest for metallic hydrogen is a major goal for both theoretical and experimental condensed matter physics. Hydrogen and deuterium have been compressed up to 200 GPa in diamond anvil cells, without any clear evidence for a metallic behaviour. Loubeyere has recently suggested that hydrogen could metallize, at pressures within experimental range, in a new Van der Waals compound: Ar(H 2 ) 2 which is characterized at ambient pressure by an open and anisotropic sublattice of hydrogen molecules, stabilized by an argon skeleton. This thesis deals with a detailed ab initio investigation, by Car-Parrinello molecular dynamics methods, of the evolution under pressure of this compound. In a last chapter, we go to much higher pressures and temperatures, in order to compare orbital and orbital free ab initio methods for the dense hydrogen plasma. (author)

  7. Liquid metal cooled nuclear reactors

    International Nuclear Information System (INIS)

    Scott, D.

    1981-01-01

    An improved method of constructing the diagrid used to support fuel assemblies of liquid metal fast breeder reactors, is described. The functions of fuel assembly support and coolant plenum are performed by discrete components of the diagrid each of which can serve the function of the other in the event of failure of one of the components. (U.K.)

  8. Liquid metal thermal-hydraulics

    International Nuclear Information System (INIS)

    Kottowski-Duemenil, H.M.

    1994-01-01

    This textbook is a report of the 26 years activity of the Liquid Metal Boiling Working Group (LMBWG). It summarizes the state of the art of liquid metal thermo-hydraulics achieved through the collaboration of scientists concerned with the development of the Fast Breeder Reactor. The first chapter entitled ''Liquid Metal Boiling Behaviour'', presents the background and boiling mechanisms. This section gives the reader a brief but thorough survey on the superheat phenomena in liquid metals. The second chapter of the text, ''A Review of Single and Two-Phase Flow Pressure Drop Studies and Application to Flow Stability Analysis of Boiling Liquid Metal Systems'' summarizes the difficulty of pressure drop simulation of boiling sodium in core bundles. The third chapter ''Liquid Metal Dry-Out Data for Flow in Tubes and Bundles'' describes the conditions of critical heat flux which limits the coolability of the reactor core. The fourth chapter dealing with the LMFBR specific topic of ''Natural Convection Cooling of Liquid Metal Systems''. This chapter gives a review of both plant experiments and out-of-pile experiments and shows the advances in the development of computing power over the past decade of mathematical modelling ''Subassembly Blockages Suties'' are discussed in chapter five. Chapter six is entitled ''A Review of the Methods and Codes Available for the Calculation on Thermal-Hydraulics in Rod-Cluster and other Geometries, Steady state and Transient Boiling Flow Regimes, and the Validation achieves''. Codes available for the calculation of thermal-hydraulics in rod-clusters and other geometries are reviewed. Chapter seven, ''Comparative Studies of Thermohydraulic Computer Code Simulations of Sodium Boiling under Loss of Flow Conditions'', represents one of the key activities of the LMBWG. Several benchmark exercises were performed with the aim of transient sodium boiling simulation in single channels and bundle blockages under steady state conditions and loss of

  9. Liquid hydrogen and deuterium targets; Cibles a hydrogene et deuterium liquides

    Energy Technology Data Exchange (ETDEWEB)

    Bougon, M; Marquet, M; Prugne, P [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1961-07-01

    A description is given of 1) Atmospheric pressure target: liquid hydrogen, 400 mm thickness; thermal insulation: styrofoam; the hydrogen vapors are used to improve the target cooling; Mylar windows. 2) Vacuum target: 12 liter content: hydrogen or deuterium; liquid thickness 400 mm; thermal insulation is afforded by a vacuum vessel and a liquid nitrogen shield. Recovery and liquefaction of deuterium vapors are managed in the vacuum vessel which holds the target. The target emptying system is designed for operating in a few minutes. (author) [French] Description de: 1) Cible a pression atmospherique; hydrogene liquide, 400 mm d'epaisseur; l'isolement thermique: styrofoam; on utilise les vapeurs d'hydrogene pour ameliorer le refroidissement de la cible; hublots en Mylar. 2) Cible sous vide; contenance 12 litres; hydrogene ou deuterium; epaisseur du liquide 400 mm; l'isolement thermique est assure par une cuve a vide et un ecran d'azote liquide. Recuperation et liquefaction des vapeurs de deuterium sont effectuees dans la cuve a vide contenant la cible. Le systeme de vidange pour la cible est concu pour fonctionner en quelques minutes. (auteur)

  10. Interaction of hydrogen with metallic nanojunctions

    Energy Technology Data Exchange (ETDEWEB)

    Halbritter, Andras; Csonka, Szabolcs; Makk, Peter; Mihaly, Gyoergy [Electron Transport Research Group of the Hungarian Academy of Sciences and Department of Physics, Budapest University of Technology and Economics, 1111 Budapest (Hungary)

    2007-03-15

    We study the behavior of hydrogen molecules between atomic-sized metallic electrodes using the mechanically controllable break junction technique. We focus on the interaction H{sub 2} with monoatomic gold chains demonstrating the possibility of a hydrogen molecule being incorporated in the chain. We also show that niobium is strongly reactive with hydrogen, which enables molecular transport studies between superconducting electrodes. This opens the possibility for a full characterization of the transmission properties of molecular junctions with superconducting subgap structure measurements.

  11. Hydrogen-induced high damping of bulk metallic glasses

    International Nuclear Information System (INIS)

    Hasegawa, M.

    2009-01-01

    There are two important topics concerned with the recent researches on the damping materials of hydrogenated metallic glasses (HMGs). One is the mechanism of the high hydrogen-induced internal friction of HMGs. The other is the materials processing of 'bulk' HMGs for engineering. This article describes the summary of our recent studies on these topics. The first one is closely related to the local structure of the metallic glasses. Therefore, our recent results on the intermediate-range local structure of the simple two Zr-based metallic glasses are described, which has been clarified by the Voronoi analysis using the experimental data of the neutron diffraction measurements. The hydrogen-induced internal friction of HMGs is also discussed on the basis of these recent results of the local structure of the metallic glasses. In terms of the second topic, the first successful preparation of heavily hydrogenated Zr-based bulk HMG rods without hydrogen-induced surface embrittlement is described. They are prepared by a powder-compact-melting and liquid-casting process using Zr-Al-Ni-Cu metallic glass and ZrH 2 powders as the starting materials. It has been found that they have high damping properties.

  12. Hydrogen and helium recycling from a JxB-force convected liquid metal Ga{sub 67}In{sub 20.5}Sn{sub 12.5} under steady state plasma bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Hirooka, Yoshi, E-mail: hirooka.yoshihiko@nifs.ac.jp [National institute for Fusion Science, Oroshi, Toki, Gifu 509-5292 (Japan); Graduate University for Advanced Studies, Oroshi, Toki, Gifu 509-5292 (Japan); Bi, Hailin [Graduate University for Advanced Studies, Oroshi, Toki, Gifu 509-5292 (Japan); Shimada, Michiya [Japan Atomic Energy Agency, Rokkasho, Kamikita, Aomori 039-3212 (Japan); Ono, Masa [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States)

    2017-04-15

    A series of first-of-a-kind laboratory-scale experiments on the JxB-force convected liquid metal divertor concept have been carried out in the temperature range from room temperature to ∼200 °C, employing a eutectic alloy: Ga{sub 67}In{sub 20.5}Sn{sub 12.5}, the melting point of which is 10.5 °C. The electrical current conducted through the alloy is set at about 70A and the magnetic field is set at about 700 G. It has reproducibly been observed that hydrogen as well as helium particle recycling is noticeably reduced under steady state plasma bombardment when the liquid is convected by the JxB force.

  13. Mechanisms of dispersion during liquid hydrogen leakage

    International Nuclear Information System (INIS)

    Proust, C.; Gaston, D.

    2000-01-01

    INERIS conducts research programs with a mission of assessing and preventing accidental and chronic risks to people and the environment due to industrial plants, chemical substances and underground operation. This paper is a study of the dispersion mechanism of cryogenic hydrogen and the mechanisms of flame propagation in clouds of hydrogen. The objective is to contribute to the industrial control implementation of significant storage of hydrogen liquid that has pressure close to the atmospheric pressure. Within the framework of this program, the only interest is with the risk presented by escape of significant flow. This corresponds to accidental ruptures in tanks. The following four phases are looked at: the escape incident and the determination of the leak flow; the formation of the liquid layer and the vaporization of the hydrogen; the formation of the Hydrogen cloud in air; and the explosive ignition in the atmosphere, propagation of the explosive flame and evaluation of the pressure wave. This situation has been limited to dispersion in free air and does not consider the impact of containment

  14. Motor fuels by hydrogenation of liquid hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    1938-05-07

    A process is disclosed for the production of knock-stable low-boiling motor fuels by conversion of liquid hydrocarbons which are vaporizable under the reaction conditions, which comprises passing the initial material at a temperature above 380/sup 0/C in a true vapor phase under pressure of more than 40 atmospheres together with hydrogen and gaseous hydrocarbons containing more than 1 carbon atom in the molecule in an amount by volume larger than that of the hydrogen over catalysts stable to poisoning stationarily confined in the reaction vessel.

  15. Hydrogen axion star: metallic hydrogen bound to a QCD axion BEC

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Yang; Barger, Vernon; Berger, Joshua [Department of Physics, University of Wisconsin-Madison,1150 University Ave, Madison, WI 53706 (United States)

    2016-12-23

    As a cold dark matter candidate, the QCD axion may form Bose-Einstein condensates, called axion stars, with masses around 10{sup −11} M{sub ⊙}. In this paper, we point out that a brand new astrophysical object, a Hydrogen Axion Star (HAS), may well be formed by ordinary baryonic matter becoming gravitationally bound to an axion star. We study the properties of the HAS and find that the hydrogen cloud has a high pressure and temperature in the center and is likely in the liquid metallic hydrogen state. Because of the high particle number densities for both the axion star and the hydrogen cloud, the feeble interaction between axion and hydrogen can still generate enough internal power, around 10{sup 13} W×(m{sub a}/5 meV){sup 4}, to make these objects luminous point sources. High resolution ultraviolet, optical and infrared telescopes can discover HAS via black-body radiation.

  16. Liquid hydrogen production and commercial demand in the United States

    Science.gov (United States)

    Heydorn, Barbara

    1990-01-01

    Kennedy Space Center, the single largest purchaser of liquid hydrogen (LH2) in the United States, evaluated current and anticipated hydrogen production and consumption in the government and commercial sectors. Specific objectives of the study are as follows: (1) identify LH2 producers in the United States and Canada during 1980-1989 period; (2) compile information in expected changes in LH2 production capabilities over the 1990-2000 period; (3) describe how hydrogen is used in each consuming industry and estimate U.S. LH2 consumption for the chemicals, metals, electronics, fats and oil, and glass industries, and report data on a regional basis; (4) estimate historical and future consumption; and (5) assess the influence of international demands on U.S. plants.

  17. Resistance probe for liquid hydrogen; Sonde a resistance pour l'hydrogene liquide

    Energy Technology Data Exchange (ETDEWEB)

    Beauval, J J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    A simple device for determining the level of a liquid in equilibrium with its vapour is described. It makes use of the variation in heat exchange between a filament heated by a current and the atmosphere, on passing from the liquid to the gas. This apparatus is used to measure liquid hydrogen levels in liquefying dewar vessels. (author) [French] On decrit un dispositif simple permettant de determiner le niveau d'un liquide en equilibre avec sa vapeur. Il utilise la variation de l'echange thermique entre un filament chauffe par un courant et le milieu ambiant, quand on passe du liquide au gaz. Cet appareil est utilise pour mesurer des niveaux d'hydrogene liquide dans les dewars du liquefacteur. (auteur)

  18. Liquid Metal Engineering and Technology. Volume 1

    International Nuclear Information System (INIS)

    1988-01-01

    These proceedings of the fourth international conference on liquid metal engineering and technology volume 1, are devided into 3 sections bearing on: - Apparatus and components for liquid metal (29 papers) - Liquid metal leaks, fires and fumes (10 papers) - Cleaning, decontamination, waste disposal (14 papers) [fr

  19. Metal extraction by solid-liquid agglomerates

    International Nuclear Information System (INIS)

    Fuller, E.F.

    1980-01-01

    Dissolved metal values are extracted from a liquid e.g. uranium from phosphoric acid by contacting the liquid with agglomerates for a time to load the agglomerate with the metal value, separating the loaded agglomerates from the liquid phase and stripping the metal value from the loaded agglomerate. The agglomerate may be made by combining finely divided solid particles with a binding liquid to form a paste, adding a suspending liquid to form a mixture, the suspending liquid and binding liquid being immiscible in each other and the solid particles being insoluble in the suspending liquid and shearing the mixture to form the agglomerate. (author)

  20. Analysis of hydrogen in zirconium metallic

    International Nuclear Information System (INIS)

    Rodrigues, A.N.; Vega Bustillos, J.O.W.

    1991-02-01

    Determination of hydrogen in zirconium metallic have been performed using the hot vacuum extraction system and the gas chromatographic technique. The zirconium metallic samples were hydrieded by electrolitic technique at difference temperatures and times, then the samples were annealing at vacuum and eatching by fluoridric acid solution. The details of the hydrieded process, analytical technique and the data obtained are discussed. (author)

  1. Theory of hydrogen chemisorption on metals

    International Nuclear Information System (INIS)

    Brenig, W.

    1975-01-01

    A theory of hydrogen chemisorption on metals is presented. Green's function is derived taking into account the coupling strength between metal and chemisorbed atom and the strength of the interatomic Coulomb repulsion, allowing the calculation of the local density of states at the adatom, especially for the limiting cases of strong and weak coupling

  2. Liquid metals: fundamentals and applications in chemistry.

    Science.gov (United States)

    Daeneke, T; Khoshmanesh, K; Mahmood, N; de Castro, I A; Esrafilzadeh, D; Barrow, S J; Dickey, M D; Kalantar-Zadeh, K

    2018-04-03

    Post-transition elements, together with zinc-group metals and their alloys belong to an emerging class of materials with fascinating characteristics originating from their simultaneous metallic and liquid natures. These metals and alloys are characterised by having low melting points (i.e. between room temperature and 300 °C), making their liquid state accessible to practical applications in various fields of physical chemistry and synthesis. These materials can offer extraordinary capabilities in the synthesis of new materials, catalysis and can also enable novel applications including microfluidics, flexible electronics and drug delivery. However, surprisingly liquid metals have been somewhat neglected by the wider research community. In this review, we provide a comprehensive overview of the fundamentals underlying liquid metal research, including liquid metal synthesis, surface functionalisation and liquid metal enabled chemistry. Furthermore, we discuss phenomena that warrant further investigations in relevant fields and outline how liquid metals can contribute to exciting future applications.

  3. Application of liquid metals for the extraction of solid metals

    International Nuclear Information System (INIS)

    Borgstedt, H.U.

    1996-01-01

    Liquid metals dissolve several solid metals in considerable amounts at moderate temperatures. The dissolution processes may be based upon simple physical solubility, formation of intermetallic phases. Even chemical reactions are often observed in which non-metallic elements might be involved. Thus, the capacity to dissolve metals and chemical properties of the liquid metals play a role in these processes. Besides the solubility also chemical properties and thermochemical data are of importance. The dissolution of metals in liquid metals can be applied to separate the solutes from other metals or non-metallic phases. Relatively noble metals can be chemically reduced by the liquid phases. Such solution processes can be applied in the extractive metallurgy, for instance to extract metals from metallic waste. The recycling of metals is of high economical and ecological importance. Examples of possible processes are discussed. (author)

  4. Hydrogen influence on metals behaviour

    International Nuclear Information System (INIS)

    Tison, P.

    1984-01-01

    Hydrogen isotopes are used in order to investigate the influence of natural oxides and trapping on the permeability of low alloys steels, and martensitic, ferritic, austenitic stainless steels. The permeability of superficial oxides is investigated by reducing and reoxidising the upstream and downstream surfaces (gas ingoing and outgoing faces). The simultaneous or successive use of hydrogen and deuterium enables a direct demonstration of trapping during permeation measurements and a study of the interactions between the diffusing gas and hydrogen absorbed during steel making and processing [fr

  5. Metallic Hydrogen: A Game Changing Rocket Propellant

    Science.gov (United States)

    Silvera, Isaac F.

    2016-01-01

    The objective of this research is to produce metallic hydrogen in the laboratory using an innovative approach, and to study its metastability properties. Current theoretical and experimental considerations expect that extremely high pressures of order 4-6 megabar are required to transform molecular hydrogen to the metallic phase. When metallic hydrogen is produced in the laboratory it will be extremely important to determine if it is metastable at modest temperatures, i.e. remains metallic when the pressure is released. Then it could be used as the most powerful chemical rocket fuel that exists and revolutionize rocketry, allowing single-stage rockets to enter orbit and chemically fueled rockets to explore our solar system.

  6. Liquid-metal-cooled reactor

    International Nuclear Information System (INIS)

    Zhuchkov, I.I.; Filonov, V.S.; Zaitsev, B.I.; Artemiev, L.N.; Rakhimov, V.V.

    1976-01-01

    A liquid-metal-cooled reactor is described comprising two rotatable plugs, one of them, having at least one hole, being arranged internally of the other, a recharging mechanism with a guide tube adapted to be moved through the hole of the first plug by means of a drive, and a device for detecting stacks with leaky fuel elements, the recharging mechanism tube serving as a sampler

  7. Liquid metal-organic frameworks

    Science.gov (United States)

    Gaillac, Romain; Pullumbi, Pluton; Beyer, Kevin A.; Chapman, Karena W.; Keen, David A.; Bennett, Thomas D.; Coudert, François-Xavier

    2017-11-01

    Metal-organic frameworks (MOFs) are a family of chemically diverse materials, with applications in a wide range of fields, covering engineering, physics, chemistry, biology and medicine. Until recently, research has focused almost entirely on crystalline structures, yet now a clear trend is emerging, shifting the emphasis onto disordered states, including `defective by design’ crystals, as well as amorphous phases such as glasses and gels. Here we introduce a strongly associated MOF liquid, obtained by melting a zeolitic imidazolate framework. We combine in situ variable temperature X-ray, ex situ neutron pair distribution function experiments, and first-principles molecular dynamics simulations to study the melting phenomenon and the nature of the liquid obtained. We demonstrate from structural, dynamical, and thermodynamical information that the chemical configuration, coordinative bonding, and porosity of the parent crystalline framework survive upon formation of the MOF liquid.

  8. Optical hydrogen sensors based on metal-hydrides

    Science.gov (United States)

    Slaman, M.; Westerwaal, R.; Schreuders, H.; Dam, B.

    2012-06-01

    For many hydrogen related applications it is preferred to use optical hydrogen sensors above electrical systems. Optical sensors reduce the risk of ignition by spark formation and are less sensitive to electrical interference. Currently palladium and palladium alloys are used for most hydrogen sensors since they are well known for their hydrogen dissociation and absorption properties at relatively low temperatures. The disadvantages of palladium in sensors are the low optical response upon hydrogen loading, the cross sensitivity for oxygen and carbon, the limited detection range and the formation of micro-cracks after some hydrogen absorption/desorption cycles. In contrast to Pd, we find that the use of magnesium or rear earth bases metal-hydrides in optical hydrogen sensors allow tuning of the detection levels over a broad pressure range, while maintaining a high optical response. We demonstrate a stable detection layer for detecting hydrogen below 10% of the lower explosion limit in an oxygen rich environment. This detection layer is deposited at the bare end of a glass fiber as a micro-mirror and is covered with a thin layer of palladium. The palladium layer promotes the hydrogen uptake at room temperature and acts as a hydrogen selective membrane. To protect the sensor for a long time in air a final layer of a hydrophobic fluorine based coating is applied. Such a sensor can be used for example as safety detector in automotive applications. We find that this type of fiber optic hydrogen sensor is also suitable for hydrogen detection in liquids. As example we demonstrate a sensor for detecting a broad range of concentrations in transformer oil. Such a sensor can signal a warning when sparks inside a high voltage power transformer decompose the transformer oil over a long period.

  9. Neutronographic measurements of the motion of hydrogen and hydrogeneous substances in liquids and solids

    International Nuclear Information System (INIS)

    Zeilinger, A.; Pochman, W.A.; Rauch, H.; Suleiman, M.

    1976-01-01

    Earlier measurements of hydrogen motion in liquids by neutron radiography have been extended to obtain additional parameters of governing the mixing behavior of light and heavy water. Furthermore motion of water in concrete was measured leading to a determination of (1) the vapor diffusion coefficient of water in concrete, (2) the porosity of the concrete, and (3) the mass transfer coefficient of vapor from the concrete to the environment. Recently the ability of neutron radiography to measure the hydrogen motion in metals was demonstrated and the diffusion coefficients of hydrogen in V, Ta, Nb and beta-Ti was determined. In addition, some work on resolution measurements of neutron radiography will be reported. (author)

  10. Solubility of Hydrogen and Nitrogen in liquid cast iron during melting and mold filling

    OpenAIRE

    Diószegi, Attila; Elfsberg, Jessica; Diószegi, Zoltán

    2016-01-01

    Defect formation like gas- and shrinkage porosity at cast iron component production is related to the content of gaseous elements in the liquid metal. The present work investigate the solubility of hydrogen and nitrogen in liquid iron aimed for production of lamellar and compacted graphite cast iron. The used methods and instruments are a combination of commercial measuring devices and novel experimental assemblies for measuring solubility of hydrogen and nitrogen during melting and mold fill...

  11. Liquid metal Flow Meter - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, C.; Hoogendoom, S.; Hudson, B.; Prince, J.; Teichert, K.; Wood, J.; Chase, K.

    2007-01-30

    Measuring the flow of liquid metal presents serious challenges. Current commercially-available flow meters use ultrasonic, electromagnetic, and other technologies to measure flow, but are inadequate for liquid metal flow measurement because of the high temperatures required by most liquid metals. As a result of the reactivity and high temperatures of most liquid metals, corrosion and leakage become very serious safety concerns. The purpose of this project is to develop a flow meter for Lockheed Martin that measures the flow rate of molten metal in a conduit.

  12. Specificity in liquid metal induced embrittlement

    CSIR Research Space (South Africa)

    Fernandes, PJL

    1996-12-01

    Full Text Available One of the most intriguing features of liquid metal induced embrittlement (LMIE) is the observation that some liquid metal-solid metal couples are susceptible to embrittlement, while others appear to be immune. This is referred to as the specificity...

  13. Liquid metals replace water steam

    Energy Technology Data Exchange (ETDEWEB)

    Kozlov, V

    1976-12-01

    The techniques are described of power generation with regard to their effectiveness which depends on the efficiency of the conversion of thermal energy into electric energy. The magnetohydrodynamic conversion of energy is based on the use of induced electromotive force which results from the movement of the conductor in the magnetic field. The use of liquid metal as the working medium makes it possible to increase the initial temperature of the magnetohydrodynamic cycle to the limit of the highest technically attainable temperatures. The total efficiency of energy conversion in magnetohydrodynamic converters is 2 to 6%.

  14. Liquid metals replace water steam

    International Nuclear Information System (INIS)

    Kozlov, V.

    1976-01-01

    The techniques are described of power generation with regard to their effectiveness which depends on the efficiency of the conversion of thermal energy into electric energy. The magnetohydrodynamic conversion of energy is based on the use of induced electromotive force which results from the movement of the conductor in the magnetic field. The use of liquid metal as the working medium makes it possible to increase the initial temperature of the magnetohydrodynamic cycle to the limit of the highest technically attainable temperatures. The total efficiency of energy conversion in magnetohydrodynamic converters is 2 to 6%. (J.B.)

  15. Bearing for liquid metal pump

    International Nuclear Information System (INIS)

    Dickinson, R.J.; Pennell, W.E.; Wasko, J.

    1984-01-01

    A liquid metal pump bearing support comprises a series of tangentially oriented spokes that connect the bearing cylinder to the pump internals structure. The spokes may be arranged in a plurality of planes extending from the bearing cylinder to the pump internals with the spokes in one plane being arranged alternately with those in the next plane. The bearing support structure provides the pump with sufficient lateral support for the bearing structure together with the capability of accommodating differential thermal expansion without adversely affecting pump performance

  16. Liquid metal reactor absorber technology

    International Nuclear Information System (INIS)

    Pitner, A.L.

    1990-10-01

    The selection of boron carbide as the reference liquid metal reactor absorber material is supported by results presented for irradiation performance, reactivity worth compatibility, and benign failure consequences. Scram response requirements are met easily with current control rod configurations. The trend in absorber design development is toward larger sized pins with fewer pins per bundle, providing economic savings and improved hydraulic characteristics. Very long-life absorber designs appear to be attainable with the application of vented pin and sodium-bonded concepts. 3 refs., 3 figs

  17. Microporous Metal Organic Materials for Hydrogen Storage

    Energy Technology Data Exchange (ETDEWEB)

    S. G. Sankar; Jing Li; Karl Johnson

    2008-11-30

    We have examined a number of Metal Organic Framework Materials for their potential in hydrogen storage applications. Results obtained in this study may, in general, be summarized as follows: (1) We have identified a new family of porous metal organic framework materials with the compositions M (bdc) (ted){sub 0.5}, {l_brace}M = Zn or Co, bdc = biphenyl dicarboxylate and ted = triethylene diamine{r_brace} that adsorb large quantities of hydrogen ({approx}4.6 wt%) at 77 K and a hydrogen pressure of 50 atm. The modeling performed on these materials agree reasonably well with the experimental results. (2) In some instances, such as in Y{sub 2}(sdba){sub 3}, even though the modeling predicted the possibility of hydrogen adsorption (although only small quantities, {approx}1.2 wt%, 77 K, 50 atm. hydrogen), our experiments indicate that the sample does not adsorb any hydrogen. This may be related to the fact that the pores are extremely small or may be attributed to the lack of proper activation process. (3) Some samples such as Zn (tbip) (tbip = 5-tert butyl isophthalate) exhibit hysteresis characteristics in hydrogen sorption between adsorption and desorption runs. Modeling studies on this sample show good agreement with the desorption behavior. It is necessary to conduct additional studies to fully understand this behavior. (4) Molecular simulations have demonstrated the need to enhance the solid-fluid potential of interaction in order to achieve much higher adsorption amounts at room temperature. We speculate that this may be accomplished through incorporation of light transition metals, such as titanium and scandium, into the metal organic framework materials.

  18. Reflector optimization for coupled liquid hydrogen moderator

    International Nuclear Information System (INIS)

    Kiyanagi, Y.; Iwasa, H.; Watanabe, N.; Furusaka, M.

    1991-01-01

    As a part of optimization studies on a coupled liquid hydrogen moderator system, the optimal thickness of the reflector, the effects of neutron absorbing liners and other beam hole/moderator on the cold-neutron-beam intensity were studied experimentally. It turns out that the optimal thickness is rather thick in this system and the existence of Cd liners around the beam extraction hole considerably reduces the cold neutron beam intensity, while the existence of other beam hole and moderator does not give an important intensity reduction. (author)

  19. Screen Channel Liquid Acquisition Device Outflow Tests in Liquid Hydrogen

    Science.gov (United States)

    Hartwig, Jason W.; Chato, David J.; McQuillen, J. B.; Vera, J.; Kudlac, M. T.; Quinn, F. D.

    2013-01-01

    This paper presents experimental design and test results of the recently concluded 1-g inverted vertical outflow testing of two 325x2300 full scale liquid acquisition device (LAD) channels in liquid hydrogen (LH2). One of the channels had a perforated plate and internal cooling from a thermodynamic vent system (TVS) to enhance performance. The LADs were mounted in a tank to simulate 1-g outflow over a wide range of LH2 temperatures (20.3 - 24.2 K), pressures (100 - 350 kPa), and flow rates (0.010 - 0.055 kg/s). Results indicate that the breakdown point is dominated by liquid temperature, with a second order dependence on mass flow rate through the LAD. The best performance is always achieved in the coldest liquid states for both channels, consistent with bubble point theory. Higher flow rates cause the standard channel to break down relatively earlier than the TVS cooled channel. Both the internal TVS heat exchanger and subcooling the liquid in the propellant tank are shown to significantly improve LAD performance.

  20. The thermophysical properties of metallic liquids

    CERN Document Server

    Iida, Takamichi

    2015-01-01

    The main purpose of materials science and engineering is to make the best use of all the elements in the periodic table. This leads to the effective use and conservation of natural resources. For this purpose, in any liquid metallic processing operation, accurate data for the thermophysical properties of all metallic liquids (i.e. liquid metals, semimetals, and semiconductors) is needed. However, in addition, a clear understanding of the essence of their thermophysical properties, based on these data, is indispensable. The second volume continues from the first volume to provide explanations for the thermophysical properties of metallic liquids. The two volumes identify new dimensionless parameters, extracted from the velocity of sound. In spite of being simple parameters, they provide useful information on the nature and behaviour of metallic liquids. This volume covers several basic concepts needed to understand the thermophysical properties of metallic liquids and for developing reliable models to accurate...

  1. Multipurpose sampler device for liquid metal

    International Nuclear Information System (INIS)

    Nelson, P.A.; Kolba, V.M.; Holmes, J.T.

    1975-01-01

    A device for collecting samples or examining a flow of liquid metal is provided for use with such as a liquid-metal-cooled nuclear reactor. The sampler device includes a casing surrounded by an external heater for establishing an upper isothermal zone and a lower zone for heating the entering liquid metal. One of various inserts is suspended into the isothermal zone where it is surrounded by a shroud tube for directing liquid-metal flow from the heating zone into the top of the insert. Discharge flow from the insert gravitates through a helically wound tube in heat exchange contact with entering liquid-metal flow within the heating zone. The inserts comprise an overflow cup with upper and lower freeze seals, a filter for removing particulate matter, and a fixture for maintaining various sample materials in equilibrium with liquid-metal flow. (U.S.)

  2. Hydrogen storage properties of metallic hydrides

    International Nuclear Information System (INIS)

    Latroche, M.; Percheron-Guegan, A.

    2005-01-01

    Nowadays, energy needs are mainly covered by fossil energies leading to pollutant emissions mostly responsible for global warming. Among the different possible solutions for greenhouse effect reduction, hydrogen has been proposed for energy transportation. Indeed, H 2 can be seen as a clean and efficient energy carrier. However, beside the difficulties related to hydrogen production, efficient high capacity storage means are still to be developed. Many metals and alloys are able to store large amounts of hydrogen. This latter solution is of interest in terms of safety, global yield and long term storage. However, to be suitable for applications, such compounds must present high capacity, good reversibility, fast reactivity and sustainability. In this paper, we will review the structural and thermodynamic properties of metallic hydrides. (authors)

  3. Liquid metals fire control engineering handbook

    International Nuclear Information System (INIS)

    Ballif, J.L.

    1979-02-01

    This handbook reviews the basic requirements of the use of liquid metals with emphasis on sodium which has the greatest current usage. It delineates the concepts necessary to design facilities both radioactive and nonradioactive for use with liquid metals. It further reviews the state-of-the-art in fire extinguishers and leak detection equipment and comments on their application and sensitivity. It also provides details on some engineering features of value to the designer of liquid metal facilities

  4. Liquid metal corrosion considerations in alloy development

    International Nuclear Information System (INIS)

    Tortorelli, P.F.; DeVan, J.H.

    1984-01-01

    Liquid metal corrosion can be an important consideration in developing alloys for fusion and fast breeder reactors and other applications. Because of the many different forms of liquid metal corrosion (dissolution, alloying, carbon transfer, etc.), alloy optimization based on corrosion resistance depends on a number of factors such as the application temperatures, the particular liquid metal, and the level and nature of impurities in the liquid and solid metals. The present paper reviews the various forms of corrosion by lithium, lead, and sodium and indicates how such corrosion reactions can influence the alloy development process

  5. Technique for detecting liquid metal leaks

    International Nuclear Information System (INIS)

    Bauerle, J.E.

    1979-01-01

    In a system employing flowing liquid metal as a heat transfer medium in contact with tubular members containing a working fluid, i.e., steam, liquid metal leaks through the wall of the tubular member are detected by dislodging the liquid metal compounds forming in the tubular member at the leak locations and subsequently transporting the dislodged compound in the form of an aerosol to a detector responsive to the liquid metal compound. In the application to a sodium cooled tubular member, the detector would consist of a sodium responsive device, such as a sodium ion detector

  6. Realization of a liquid hydrogen target

    International Nuclear Information System (INIS)

    Libin, J.F.; Gangnant, F.

    1997-01-01

    Experiments by the SPEG facility at GANIL need liquid hydrogen targets of some cm 3 . To achieve such targets, temperatures lower than 20 K must be obtained while their thin windows must withstand to pressures higher than 1000 m bars at these temperatures. Havar windows of 4.4 μm thickness met these requirements. A RW5 type Leybold cryo-generator was used as well as a system of ohmic heaters allowing regaining the initial state in a time equivalent with time elapsed for cooling. The working regime was chosen to be constant volume - variable pressure. The various components of this equipment (cryogenic head, buffer volume, hydrogen reservoir and vacuum pump) were coupled through 'aeroquip' allowing by dismantling and changes to keep the hydrogen isolated from the ambient atmosphere. The tests confirmed the accuracy of estimations done for the buffer volume and pressure. The only uncertainty is related to the window deformations. The time of cooling and reheating of target is around one hour. This allows during an experiment to aerate the chamber as the target was accessible to any necessary intervention

  7. Evolution of the liquid metal reactor

    International Nuclear Information System (INIS)

    Till, C.E.; Chang, Y.I.

    1989-01-01

    This paper reports on the integral fat reactor (IFR) concept. A key feature of the IFR concept is the metallic fuel, the original choice in liquid metal reactor development. An IFR development program is detailed by the authors

  8. Determination of hydrogen in metals and alloys

    International Nuclear Information System (INIS)

    Sayi, Y.S.; Ramanjaneyulu, P.S.; Ramakumar, K.L.

    2008-01-01

    Hydrogen will be invariably present in all materials. Its presence in excess is harmful and sometimes calamitous. Hydrogen embrittlement can occur quite readily in most high strength materials, irrespective of their composition or structure. It is therefore essential to maintain low levels of hydrogen. To know the amount of hydrogen present in the materials, it is essential to determine it with high degree of precision and accuracy. It is required to give the uncertainty associated with the measurement to increase the confidence on measurements. Several methodologies are available for the determination of hydrogen. It its isotope, deuterium, also co-exists it becomes all the more difficult to determine these individually. Hot vacuum extraction cum quadrupole mass spectrometry (HVE-QMS) developed in our laboratory to determine hydrogen and deuterium is routinely employed for the determination of hydrogen and deuterium in metals and alloys. The present paper deals in detail about our experiences with HVE-QMS and estimation of uncertainty associated in this methodology. (author)

  9. The SAFR liquid metal concept

    International Nuclear Information System (INIS)

    Baumeister, E.B.

    1987-01-01

    The Sodium Advanced Fast Reactor (SAFR) modular reactor concept is being developed by the team of Rockwell International, Combustion Engineering, and Bechtel under the U.S. Department of Energy's (DOE's) Advanced Liquid Metal Reactor (LMR) program. The SAFR plant would provide a viable alternate to light water reactors, especially for applications favoring small incremental capacity additions. SAFR is also a logical step to facilitate the later transition to LMFBRs. The SAFR plant concept employs multiple 350-MWe LMR Power Pak modules. Each Power Pak is a standardized, shop-fabricated unit that can be barge-shipped to the plant site for installation. The 350-MWe size allows SAFR to capitalize on all the inherent safety features provided by small reactors and factory fabrication, while still preserving some economy of scale. Shop fabrication minimizes nuclear-grade field fabrication and minimizes the overall plant construction schedule and capital cost. Each Power Pak consists of one reactor assembly and associated heat transfer equipment coupled to a single turbine generator. The reactor core employs mixed uranium-plutonium zirconium alloy metal fuel. The metal-alloy fuel (which has been used in EBR-II) has cost, safety, and safeguard advantages. The intrinsic properties of the sodium coolant (e.g., high boiling point, low vapor pressure, and strong natural convection), blended together with the pool-type LMR concept and the metal fuel, result in an inherently safe plant. Passive inherent features provide both public safety and plant investment protection. Refueling is carried out annually on each Power Pak, replacing one-fourth of the core over a 6-day refueling outage. A colocated pyroprocessing fuel cycle facility can be accommodated at the site such that no off-site shipments are required. (J.P.N.)

  10. Liquid metal MHD generator systems

    International Nuclear Information System (INIS)

    Satyamurthy, P.; Dixit, N.S.; Venkataramani, N.; Rohatgi, V.K.

    1985-01-01

    Liquid Metal MHD (LMMHD) Generator Systems are becoming increasingly important in space and terrestrial applications due to their compactness and versatility. This report gives the current status and economic viability of LMMHD generators coupled to solar collectors, fast breeder reactors, low grade heat sources and conventional high grade heat sources. The various thermodynamic cycles in the temperatures range of 100degC-2000degC have been examined. The report also discusses the present understanding of various loss mechanisms inherent in LMMHD systems and the techniques for overcoming these losses. A small mercury-air LMMHD experimental facility being set up in Plasma Physics Division along with proposals for future development of this new technology is also presented in this report. (author)

  11. Solubility and diffusion of hydrogen in pure metals and alloys

    International Nuclear Information System (INIS)

    Wipf, H.

    2001-01-01

    Basic facts are presented of the absorption of hydrogen gas by metals and the diffusion of hydrogen in metals. Specifically considered are crystalline metals without defects and lattice disorder (pure metals), low hydrogen concentrations and the possibility of high hydrogen gas pressures. The first introductory topic is a short presentation of typical phase diagrams of metal hydrogen systems. Then, hydrogen absorption is discussed and shown to be decisively determined by the enthalpy of solution, in particular by its sign which specifies whether absorption is exothermic or endothermic. The formation of high-pressure hydrogen gas bubbles in a metal, which can lead to blistering, is addressed. It is demonstrated that bubble formation will, under realistic conditions, only occur in strongly endothermically hydrogen absorbing metals. The chief aspects of hydrogen diffusion in metals are discussed, especially the large size of the diffusion coefficient and its dependence on lattice structure. It is shown that forces can act on hydrogen in metals, causing a directed hydrogen flux. Such forces arise, for instance, in the presence of stress and temperature gradients and can result in local hydrogen accumulation with potential material failure effects. The final aspect discussed is hydrogen permeation, where the absorption behavior of the hydrogen is found to be in general more decisive on the permeation rate than the value of the diffusion coefficient. (orig.)

  12. Corrosion and compatibility in liquid alkali metals

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    The literature dealing with liquid alkali metal corrosion of vanadium and its alloys is reviewed in the following subsections. Attention is given to both lithium and sodium data. Preceding this review, a brief outline of the current state of understanding of liquid metal corrosion mechanisms is provided

  13. A method of estimating hydrogen in solid and liquid samples by means of neutron thermalisation

    International Nuclear Information System (INIS)

    Carter, D.H.; Sanders, J.E.

    1967-06-01

    The count-rate of a cadmium-covered Pu239 fission chamber placed in a reactor neutron flux increases when a hydrogen-containing material is inserted due to the thermalisation of epicadmium neutrons. This effect forms the basis of a non-destructive method of estimating hydrogen in solid or liquid samples, and trial experiments to demonstrate the principles have been made. The sensitivity is such that hydrogen down to 10 p.p.m. in a typical metal should be detected. A useful feature of the method is its very low response to elements other than hydrogen. (author)

  14. Hydrogen Storage in Metal-Organic Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Long, Jeffrey R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-04-28

    The design and characterization of new materials for hydrogen storage is an important area of research, as the ability to store hydrogen at lower pressures and higher temperatures than currently feasible would lower operating costs for small hydrogen fuel cell vehicles. In particular, metal-organic frameworks (MOFs) represent promising materials for use in storing hydrogen in this capacity. MOFs are highly porous, three-dimensional crystalline solids that are formed via linkages between metal ions (e.g., iron, nickel, and zinc) and organic molecules. MOFs can store hydrogen via strong adsorptive interactions between the gas molecules and the pores of the framework, providing a high surface area for gas adsorption and thus the opportunity to store hydrogen at significantly lower pressures than with current technologies. By lowering the energy required for hydrogen storage, these materials hold promise in rendering hydrogen a more viable fuel for motor vehicles, which is a highly desirable outcome given the clean nature of hydrogen fuel cells (water is the only byproduct of combustion) and the current state of global climate change resulting from the combustion of fossil fuels. The work presented in this report is the result of collaborative efforts between researchers at Lawrence Berkeley National Lab (LBNL), the National Institute of Standards and Technology (NIST), and General Motors Corporation (GM) to discover novel MOFs promising for H2 storage and characterize their properties. Described herein are several new framework systems with improved gravimetric and volumetric capacity to strongly bind H2 at temperatures relevant for vehicle storage. These materials were rigorously characterized using neutron diffraction, to determine the precise binding locations of hydrogen within the frameworks, and high-pressure H2 adsorption measurements, to provide a comprehensive picture of H2 adsorption at all relevant pressures. A

  15. Solubility of hydrogen in transition metals

    International Nuclear Information System (INIS)

    Lee, H.M.

    1976-01-01

    Correlations exist between the heat of solution of hydrogen and the difference in energy between the lowest lying energy levels of the trivalent d/sup n-1/s electronic configuration and the divalent d/sup n-2/s 2 (or the tetravalent d/sup n/) configuration of the neutral gaseous atoms. The trends observed in the transition metal series are discussed in relation to the number of valence electrons per atom in the transition elements in their metallic and neutral states

  16. Tokamak with liquid metal toroidal field coil

    International Nuclear Information System (INIS)

    Ohkawa, T.; Schaffer, M.J.

    1981-01-01

    Tokamak apparatus includes a pressure vessel for defining a reservoir and confining liquid therein. A toroidal liner disposed within the pressure vessel defines a toroidal space within the liner. Liquid metal fills the reservoir outside said liner. Electric current is passed through the liquid metal over a conductive path linking the toroidal space to produce a toroidal magnetic field within the toroidal space about the major axis thereof. Toroidal plasma is developed within the toroidal space about the major axis thereof

  17. Liquid metal cooling of synchrotron optics

    International Nuclear Information System (INIS)

    Smither, R.K.

    1993-01-01

    The installation of insertion devices at existing synchrotron facilities around the world has stimulated the development of new ways to cool the optical elements in the associated x-ray beamlines. Argonne has been a leader in the development of liquid metal cooling for high heat load x-ray optics for the next generation of synchrotron facilities. The high thermal conductivity, high volume specific heat, low kinematic viscosity, and large working temperature range make liquid metals a very efficient heat transfer fluid. A wide range of liquid metals were considered in the initial phase of this work. The most promising liquid metal cooling fluid identified to date is liquid gallium, which appears to have all the desired properties and the fewest number of undesired features of the liquid metals examined. Besides the special features of liquid metals that make them good heat transfer fluids, the very low vapor pressure over a large working temperature range make liquid gallium an ideal cooling fluid for use in a high vacuum environment. A leak of the liquid gallium into the high vacuum and even into very high vacuum areas will not result in any detectable vapor pressure and may even improve the vacuum environment as the liquid gallium combines with any water vapor or oxygen present in the system. The practical use of a liquid metal for cooling silicon crystals and other high heat load applications depends on having a convenient and efficient delivery system. The requirements for a typical cooling system for a silicon crystal used in a monochromator are pumping speeds of 2 to 5 gpm (120 cc per sec to 600 cc per sec) at pressures up to 100 psi. No liquid metal pump with these capabilities was available commercially when this project was started, so it was necessary to develop a suitable pump in house

  18. The liquid hydrogen moderator at the NIST research reactor

    International Nuclear Information System (INIS)

    Williams, Robert E.; Rowe, J. Michael; Kopetka, Paul

    1997-09-01

    In 1995, the NIST research reactor was shut down for a number of modifications, including the replacement of the D 2 O cold neutron source with a liquid hydrogen moderator. When the liquid hydrogen source began operating, the flux of cold neutrons increased by a factor of six over the D 2 O source. The design and operation of the hydrogen source are described, and measurements of its performance are compared with the Monte Carlo simulations used in the design. (auth)

  19. Compatibility of materials with liquid metal targets for SNS

    International Nuclear Information System (INIS)

    DiStefano, J.R.; Pawel, S.J.; DeVan, J.H.

    1996-01-01

    Several heavy liquid metals are candidates as the target in a spallation neutron source: Hg, Pb, Bi, and Pb-Bi eutectic. Systems with these liquid metals have been used in the past and a data-base on compatibility already exists. Two major compatibility issues have been identified when selecting a container material for these liquid metals: temperature gradient mass transfer and liquid metal embrittlement or LME. Temperature gradient mass transfer refers to dissolution of material from the high temperature portions of a system and its deposition in the lower temperature areas. Solution and deposition rate constants along with temperature, ΔT, and velocity are usually the most important parameters. For most candidate materials mass transfer corrosion has been found to be proportionately worse in Bi compared with Hg and Pb. For temperatures to ∼550 degrees C, ferritic/martensitic steels have been satisfactory in Pb or Hg systems and the maximum temperature can be extended to ∼650 degrees C with additions of inhibitors to the liquid metal, e.g. Mg, Ti, Zr. Above ∼600 degrees C, austenitic stainless steels have been reported to be unsatisfactory, largely because of the mass transfer of nickel. Blockage of flow from deposition of material is usually the life-limiting effect of this type of corrosion. However, mass transfer corrosion at lower temperatures has not been studied. At low temperatures (usually < 150 degrees C), LME has been reported for some liquid metal/container alloy combinations. Liquid metal embrittlement, like hydrogen embrittlement, results in brittle fracture of a normally ductile material

  20. Mechanisms of liquid-metal embrittlement

    International Nuclear Information System (INIS)

    Popovich, V.V.

    1979-01-01

    The mechanism of the embrittlement of metals and alloys during deformation in contact with liquid metals are discussed. With 20Kh13 steel in a Pb-Sn melt and polycrystalline Al in the presence of various mercury solutions a.s examples, considered are the three main processes - adsorption, corrosion (dissolution), formation of new phases which cause the disintegration of materials under the action of liquid-metallic media. Presented are data on plastic ductile and strength properties of the above materials in the presence of liquid-metallic media. A model is described that takes into account the effect of the medium upon the plastic deformation and the part the medium plays in liquid-metallic embrittlement

  1. Scanning electrochemical microscopy determination of hydrogen flux at liquid|liquid interface with potentiometric probe

    OpenAIRE

    Jedraszko, Justyna; Nogala, Wojciech; Adamiak, Wojciech; Girault, Hubert H.; Opallo, Marcin

    2014-01-01

    Scanning electrochemical microscopy potentiometric determination of local hydrogen concentration and its flux next to the liquid|liquid interface was demonstrated. This method is based on the shift of open circuit potential of Pt-based reversible hydrogen electrode. The detection system was verified with a system generating hydrogen under galvanostatic conditions. Then, it was applied to aqueous|1,2-dichloroethane interface where hydrogen is produced with decamethylferrocene as electron donor.

  2. Turbulent magnetohydrodynamics in liquid metals

    International Nuclear Information System (INIS)

    Berhanu, Michael

    2008-01-01

    In electrically conducting fluids, the electromagnetic field is coupled with the fluid motion by induction effects. We studied different magnetohydrodynamic phenomena, using two experiments involving turbulent flows of liquid metal. The first mid-sized uses gallium. The second, using sodium, is conducted within the VKS (Von Karman Sodium) collaboration. It has led to the observation of the dynamo effect, namely converting a part of the kinetic energy of the fluid into magnetic energy. We have shown that, depending on forcing conditions, a statistically stationary dynamo, or dynamical regimes of magnetic field can be generated. In particular, polarity reversals similar to those of Earth's magnetic field were observed. Meanwhile, experiment with Gallium has been developed to study the effects of electromagnetic induction by turbulent flows in a more homogeneous and isotropic configuration than in the VKS experiment. Using data from these two experiments, we studied the advection of magnetic field by a turbulent flow and the induced fluctuations. The development of probes measuring electrical potential difference allowed us to further highlight the magnetic braking of a turbulent flow of Gallium by Lorentz force. This mechanism is involved in the saturation of the dynamo instability. (author) [fr

  3. MHD power conversion employing liquid metals

    International Nuclear Information System (INIS)

    Houben, J.W.M.A.; Massee, P.

    1969-02-01

    The work performed in the field of MHD generation of electricity by means of liquid metals is described. It is shown that the study of two-phase flows is essential in this topic of research; two-phase flows are therefore described. Two types of generators which can be utilized with liquid metals have been studied. The results of this study are described. A short survey of the prospects of other liquid metal systems which emerge from a study of the literature is given. Finally, conclusions are drawn concerning possibilities for further investigation

  4. Corrosion by liquid metals - Application to liquid sodium

    International Nuclear Information System (INIS)

    Lavielle, Lisette.

    1978-10-01

    In this bibliographic review on the corrosion by liquid metals, the first part is devoted to the theoretical aspects of the problem and the second part concerns the corrosion of steels by liquid sodium, as example. Obvious the numerous works now published, the mechanisms are still leaving bad known [fr

  5. Neutronic studies of a liquid hydrogen-water composite moderator

    International Nuclear Information System (INIS)

    Tahara, T.; Ooi, M.; Iwasa, H.; Kiyanagi, Y.; Iverson, E.B.; Crabtree, J.A.; Lucas, A.T.

    2001-01-01

    A liquid hydrogen-liquid water composite moderator may provide performance like liquid methane at high-power spallation sources where liquid methane is impractical. We have measured the neutronic properties of such a composite moderator, where a hydrogen layer 1.25 cm thick was closely backed by water layers of 1.75 cm and 3.75 cm thickness. We also studied a moderator in which a 1.75 cm water layer was closely backed by a 1.25 cm hydrogen layer. We further performed simulations for each of these systems for comparison to the experimental results. We observed enhancement of the spectral intensity in the 'thermal' energy range as compared to the spectrum from a conventional liquid hydrogen moderator. This enhancement grew more significant as the water thickness increased, although the pulse shapes became wider as well. (author)

  6. Hydrogen isotope exchange in metal hydride columns

    International Nuclear Information System (INIS)

    Wiswall, R.; Reilly, J.; Bloch, F.; Wirsing, E.

    1977-01-01

    Several metal hydrides were shown to act as chromatographic media for hydrogen isotopes. The procedure was to equilibrate a column of hydride with flowing hydrogen, inject a small quantity of tritium tracer, and observe its elution behavior. Characteristic retention times were found. From these and the extent of widening of the tritium band, the heights equivalent to a theoretical plate could be calculated. Values of around 1 cm were obtained. The following are the metals whose hydrides were studied, together with the temperature ranges in which chromatographic behavior was observed: vanadium, 0 to 70 0 C; zirconium, 500 to 600 0 C; LaNi 5 , -78 to +30 0 C; Mg 2 Ni, 300 to 375 0 C; palladium, 0 to 70 0 C. A dual-temperature isotope separation process based on hydride chromatography was demonstrated. In this, a column was caused to cycle between two temperatures while being supplied with a constant stream of tritium-traced hydrogen. Each half-cycle was continued until ''breakthrough,'' i.e., until the tritium concentration in the effluent was the same as that in the feed. Up to that point, the effluent was enriched or depleted in tritium, by up to 20%

  7. Experimental Challenges in Studying Hydrogen Absorption in Ultrasmall Metal Nanoparticles

    International Nuclear Information System (INIS)

    Zlotea, Claudia; Oumellal, Yassine; Provost, Karine; Ghimbeu, Camelia Matei

    2016-01-01

    Recent advances on synthesis, characterization, and hydrogen absorption properties of ultrasmall metal nanoparticles (defined here as objects with average size ≤3 nm) are briefly reviewed in the first part of this work. The experimental challenges encountered in performing accurate measurements of hydrogen absorption in Mg- and noble metal-based ultrasmall nanoparticles are addressed. The second part of this work reports original results obtained for ultrasmall bulk-immiscible Pd–Rh nanoparticles. Carbon-supported Pd–Rh nanoalloys in the whole binary chemical composition range have been successfully prepared by liquid impregnation method followed by reduction at 300°C. EXAFS investigations suggested that the local structure of these nanoalloys is partially segregated into Rh-rich core and Pd-rich surface coexisting within the same nanoparticles. Downsizing to ultrasmall dimensions completely suppresses the hydride formation in Pd-rich nanoalloys at ambient conditions, contrary to bulk and larger nanosized (5–6 nm) counterparts. The ultrasmall Pd 90 Rh 10 nanoalloy can absorb hydrogen-forming solid solutions under these conditions, as suggested by in situ X-ray diffraction (XRD). Apart from this composition, common laboratory techniques, such as in situ XRD, DSC, and PCI, failed to clarify the hydrogen interaction mechanism: either adsorption on developed surfaces or both adsorption and absorption with formation of solid solutions. Concluding insights were brought by in situ EXAFS experiments at synchrotron: ultrasmall Pd 75 Rh 25 and Pd 50 Rh 50 nanoalloys absorb hydrogen-forming solid solutions at ambient conditions. Moreover, the hydrogen solubility in these solid solutions is higher with increasing Pd content, and this trend can be understood in terms of hydrogen preferential occupation in the Pd-rich regions, as suggested by in situ EXAFS. The Rh-rich nanoalloys (Pd 25 Rh 75 and Pd 10 Rh 90 ) only adsorb hydrogen on the developed surface of ultrasmall

  8. Fractional Consumption of Liquid Hydrogen and Liquid Oxygen During the Space Shuttle Program

    Science.gov (United States)

    Partridge, Jonathan K.

    2011-01-01

    The Space Shuttle uses the propellants, liquid hydrogen and liquid oxygen, to meet part of the propulsion requirements from ground to orbit. The Kennedy Space Center procured over 25 million kilograms of liquid hydrogen and over 250 million kilograms of liquid oxygen during the 3D-year Space Shuttle Program. Because of the cryogenic nature of the propellants, approximately 55% of the total purchased liquid hydrogen and 30% of the total purchased liquid oxygen were used in the Space Shuttle Main Engines. The balance of the propellants were vaporized during operations for various purposes. This paper dissects the total consumption of liqUid hydrogen and liqUid oxygen and determines the fraction attributable to each of the various processing and launch operations that occurred during the entire Space Shuttle Program at the Kennedy Space Center.

  9. Liquid composition having ammonia borane and decomposing to form hydrogen and liquid reaction product

    Science.gov (United States)

    Davis, Benjamin L; Rekken, Brian D

    2014-04-01

    Liquid compositions of ammonia borane and a suitably chosen amine borane material were prepared and subjected to conditions suitable for their thermal decomposition in a closed system that resulted in hydrogen and a liquid reaction product.

  10. Hydrogen diffusion and trapping in bcc and fcc metals

    International Nuclear Information System (INIS)

    Richter, D.

    1979-01-01

    The fundamental aspects of the metal--hydrogen systems are described. The large number of anomalous properties are the reason for continuous scientific effort. The time scale of hydrogen motion is extremely short. The characteristic frequencies of the localized modes of hydrogen in Ta, Nb, or V are in the order of 10 -14 sec (energies between 0.1 to 0.2 eV); the jump frequencies for H-diffusion at elevated temperatures in those systems are between 10 +12 to 10 +13 sec -1 . They are comparable with the correlation times for diffusion in liquids and more than ten orders of magnitude larger than the jump times for nitrogen in Nb. Out of the large number of experimental data this paper will survey only some recent results on representative fcc and bcc metals for dilute H solutions. The nature of the elementary step in H-diffusion is described. Here the temperature and isotope dependence of the H-diffusion coefficient gives hints to the mechanism involved. The experimental results are discussed in terms of semiclassical and quantum mechanical diffusion theories

  11. Liquid metal cooled divertor for ARIES

    International Nuclear Information System (INIS)

    Muraviev, E.

    1995-01-01

    A liquid metal, Ga-cooled divertor design was completed for the double null ARIES-II divertor design. The design analysis indicated a surface heat flux removal capability of up to 15 MW/m 2 , and its relative easy maintenance. Design issues of configuration, thermal hydraulics, thermal stresses, liquid metal loop and safety effects were evaluated. For coolant flow control, it was found that it is necessary to use some part of the blanket cooling ducts for the draining of liquid metal from the top divertor. In order to minimize the inventory of Ga, it was recommended that the liquid metal loop equipment should be located as close to the torus as possible. More detailed analysis of transient conditions especially under accident conditions was identified as an issue that will need to be addressed

  12. Stability analysis of high temperature superconducting coil in liquid hydrogen

    International Nuclear Information System (INIS)

    Nakayama, T.; Yagai, T.; Tsuda, M.; Hamajima, T.

    2007-01-01

    Recently, it is expected that hydrogen plays an important role in energy source including electric power in near future. Liquid hydrogen has high potential for cooling down superconducting coil wound with high temperature superconductors (HTS), such as BSCCO, YBCO. In this paper, we study stabilities of the coils wound with BSCCO tapes, which are immersed in the liquid hydrogen, and compare stability results with those cooled by liquid helium. We treat a minimum propagation zone (MPZ) theory to evaluate the coil stability considering boiling heat flux of the liquid hydrogen, and specific heat, heat conduction and resistivity of HTS materials as a function of temperature. It is found that the coil cooled by the liquid hydrogen has higher stability margin than that cooled by the liquid helium. We compare the stability margins of both coils wound with Bi-2223/Ag tape and Bi-2212/Ag tape in liquid hydrogen. As a result, it is found that the stability of Bi-2212 coil is equivalent to that of Bi-2223 coil in low and high magnetic field, while the maximum current of Bi-2212 coil exceeds a little bit that of Bi-2223 coil in both magnetic fields

  13. Equipment for liquid metal pressure measurement

    International Nuclear Information System (INIS)

    Jung, J.

    1977-01-01

    Equipment is proposed for measuring liquid metal pressure in piping or a tank. An auxiliary piping is connected to the piping or tank at the measuring point. The auxiliary piping transports liquid metal to a container by means of an electromagnetic pump. The piping also houses an electromagnetic flow ratemeter connected to an electric comparator. The comparator and the electromagnetic pump are connected to the pump output generator. (Z.M.)

  14. Overview of liquid-metal MHD

    International Nuclear Information System (INIS)

    Dunn, P.F.

    1978-01-01

    The basic features of the two-phase liquid-metal MHD energy conversion under development at Argonne National Laboratory are presented. The results of system studies on the Rankine-cycle and the open-cycle coal-fired cycle options are discussed. The liquid-metal MHD experimental facilities are described in addition to the system's major components, the generator, mixer and nozzle-separator-diffuser

  15. Tritiated hydrogen conversion on heated metallic surfaces

    International Nuclear Information System (INIS)

    Ionita, G.; Mihaila, V.; Purghel, L.; Rebigan, F.

    1995-01-01

    This work reports investigations on tritiated hydrogen conversion to tritiated water on heated metallic surfaces. The HT conversion process has been revealed for copper, aluminium and stainless steel W4541 surfaces in the temperature range 150 to 300 o C, in case of the static regime and in the range 250 to 400 o C for the dynamic case. The most significant catalytic activity was shown by the copper sample. Studies on this subject are used as input information for different nuclear accident scenarios implying tritium leakage

  16. Permeation of hydrogen through metal membranes

    International Nuclear Information System (INIS)

    Wienhold, P.; Rota, E.; Waelbroeck, F.; Winter, J.; Banno, Tatsuya.

    1986-08-01

    Experiments show that the permeant flux of hydrogen through a metal membrane at low driving pressures ( r is introduced into the model as a new material constant and the rate equations are given. After the description of the wall pump effect, a variety of different limiting cases are discussed for a symmetrical permeation membrane. This is modified to the asymmetric case and to the influence of particle implantation. The permeation number W turns out to be a dimensionless quantity which characterizes the permeation range and predicts the permeant flux in steady state. (orig.)

  17. Detection of gas entrainment into liquid metals

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, T., E-mail: t.vogt@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Fluid Dynamics, 01328 Dresden (Germany); Boden, S. [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Fluid Dynamics, 01328 Dresden (Germany); Andruszkiewicz, A. [Faculty of Mechanical and Power Engineering, Wroclaw University of Technology (Poland); Eckert, K. [Technische Universität Dresden, Institute of Fluid Mechanics, 01062 Dresden (Germany); Eckert, S.; Gerbeth, G. [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Fluid Dynamics, 01328 Dresden (Germany)

    2015-12-01

    Highlights: • We present liquid metal experiments dedicated to gas entrainment on the free surface. • Ultrasonic and X-ray attenuation techniques have been used to study the mechanisms of gas entrainment. • A comparison between bubbly flow in water and GaInSn showed substantial differences. • Our results emphasize the importance of liquid metal experiments which are able to provide a suitable data base for numerical code validation. - Abstract: Entrainment of cover gas into the liquid metal coolant is one of the principal safety issues in the design of innovative liquid metal-cooled fast reactors. We present generic experimental studies of this phenomenon in low-melting metals. Ultrasonic and X-ray diagnostic tools were considered for a visualization of gas entrainment at the free surface of the melt. Laboratory experiments were conducted using the eutectic alloy GaInSn, which is liquid at room temperature. Vortex-activated entrainment of air at the free surface of a rotating flow was revealed by ultrasonic techniques. X-ray radioscopy was used to visualize the behavior of argon bubbles inside a slit geometry. The measurements reveal distinct differences between water and GaInSn, especially with respect to the process of bubble formation and the coalescence and breakup of bubbles. Our results emphasize the importance of liquid metal experiments which are able to provide a suitable data base for numerical code validation.

  18. Metallic Membranes for High Temperature Hydrogen Separation

    DEFF Research Database (Denmark)

    Ma, Y.H.; Catalano, Jacopo; Guazzone, Federico

    2013-01-01

    membrane fabrication methods have matured over the last decades, and the deposition of very thin films (1–5 µm) of Pd over porous ceramics or modified porous metal supports is quite common. The H2 permeances and the selectivities achieved at 400–500 °C were in the order of 50–100 Nm3/m/h/bar0.5 and greater......Composite palladium membranes have extensively been studied in laboratories and, more recently, in small pilot industrial applications for the high temperature separation of hydrogen from reactant mixtures such as water-gas shift (WGS) reaction or methane steam reforming (MSR). Composite Pd...... than 1000, respectively. This chapter describes in detail composite Pd-based membrane preparation methods, which consist of the grading of the support and the deposition of the dense metal layer, their performances, and their applications in catalytic membrane reactors (CMRs) at high temperatures (400...

  19. Liquid metals. Coexistence line, critical parameters, compressibility

    International Nuclear Information System (INIS)

    Filippov, L.P.

    1986-01-01

    Formulae to calculate four characteristic parameters of liquid metals (density, compressibility, critical temperature and individual parameter) according to four initial data are obtained: two values of vapor density and two values of vapor pressure. Comparison between experimental and calculation results are presented for liquid Cs, Na, Li, K, Rb

  20. Hydrogenation Reactions in Ionic Liquids. The Efficient Reduction of ...

    African Journals Online (AJOL)

    NJD

    2008-12-09

    Dec 9, 2008 ... Volatile organic solvents such as ethanol, methanol and THF are often used for the ... remained consistently high and only declined markedly on the fifth cycle. ... transferral of the viscous liquid from the hydrogenation reactor.

  1. Stretchable and Soft Electronics using Liquid Metals.

    Science.gov (United States)

    Dickey, Michael D

    2017-07-01

    The use of liquid metals based on gallium for soft and stretchable electronics is discussed. This emerging class of electronics is motivated, in part, by the new opportunities that arise from devices that have mechanical properties similar to those encountered in the human experience, such as skin, tissue, textiles, and clothing. These types of electronics (e.g., wearable or implantable electronics, sensors for soft robotics, e-skin) must operate during deformation. Liquid metals are compelling materials for these applications because, in principle, they are infinitely deformable while retaining metallic conductivity. Liquid metals have been used for stretchable wires and interconnects, reconfigurable antennas, soft sensors, self-healing circuits, and conformal electrodes. In contrast to Hg, liquid metals based on gallium have low toxicity and essentially no vapor pressure and are therefore considered safe to handle. Whereas most liquids bead up to minimize surface energy, the presence of a surface oxide on these metals makes it possible to pattern them into useful shapes using a variety of techniques, including fluidic injection and 3D printing. In addition to forming excellent conductors, these metals can be used actively to form memory devices, sensors, and diodes that are completely built from soft materials. The properties of these materials, their applications within soft and stretchable electronics, and future opportunities and challenges are considered. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Neutron radiography for visualization of liquid metal processes: bubbly flow for CO2 free production of Hydrogen and solidification processes in EM field

    Science.gov (United States)

    Baake, E.; Fehling, T.; Musaeva, D.; Steinberg, T.

    2017-07-01

    The paper describes the results of two experimental investigations aimed to extend the abilities of a neutron radiography to visualize two-phase processes in the electromagnetically (EM) driven melt flow. In the first experiment the Argon bubbly flow in the molten Gallium - a simulation of the CO2 free production of Hydrogen process - was investigated and visualized. Abilities of EM stirring for control on the bubbles residence time in the melt were tested. The second experiment was directed to visualization of a solidification front formation under the influence of EM field. On the basis of the neutron shadow pictures the form of growing ingot, influenced by turbulent flows, was considered. In the both cases rotating permanent magnets were agitating the melt flow. The experimental results have shown that the neutron radiography can be successfully employed for obtaining the visual information about the described processes.

  3. Liquid hydrogen transfer pipes and level regulation systems

    International Nuclear Information System (INIS)

    Marquet, M.; Prugne, P.; Roubeau, P.

    1961-01-01

    Describes: 1) Transfer pipes - Plunging rods in liquid hydrogen Dewars; transfer pipes: knee-joint system for quick and accurate positioning of plunging Dewar rods; system's rods: combined valve and rod; valves are activated either by a bulb pressure or by a solenoid automatically or hand controlled. The latter allows intermittent filling. 2) Level regulating systems: Level bulbs: accurate to 1 or 4 m; maximum and minimum level bulbs: automatic control of the liquid hydrogen valve. (author) [fr

  4. Metal complex derivatives of hydrogen uranyl phosphate

    International Nuclear Information System (INIS)

    Grohol, D.; Blinn, E.L.

    1994-01-01

    Derivatives of hydrogen uranyl phosphate were prepared by incorporating transition metal complexes into the uranyl phosphate matrix. The transition metal complexes employed include bis(ethylenediamine)copper(II), bis(1,3-propanediamine)copper(II) chloride, (triethylenetetramine)copper(II), (1,4,8,11-tetraazacyclotetradecane)copper(II), (1,4,8,12-tetraazacyclopentadecane)copper(II), (1,4,8,11-tetraazacyclotetradecane)nickel(II) chloride, (triethylenetetramine)nickel(II) and others. The chemical analyses of these derivatives indicated that the incorporation of the transition metal complexes into the uranyl phosphate matrix via ion exchange was not stoichiometric. The extent of ion exchange is dependent on the size and structure of the transition metal complex. All complexes were characterized by X-ray powder diffractometry, electronic and infrared spectra, thermal analyses and chemical analysis. An attempt was made to correlate the degree of quenching of the luminescence of the uranyl ion to the spacing between the uranyl phosphate layers in the derivatives

  5. Deuterium exchange between liquid water and gaseous hydrogen

    International Nuclear Information System (INIS)

    Dave, S.M.; Ghosh, S.K.; Sadhukhan, H.K.

    1982-01-01

    The overall separation factors for the deuterium exchange between liquid water and gaseous hydrogen have been calculated over a wide range of temperature, pressure and deuterium concentrations. These data would be useful in the design and other considerations for heavy water production, based on hydrogen-water exchange. (author)

  6. Structure and weak hydrogen bonds in liquid acetaldehyde

    Directory of Open Access Journals (Sweden)

    Cordeiro Maria A. M.

    2004-01-01

    Full Text Available Monte Carlo simulations have been performed to investigate the structure and hydrogen bonds formation in liquid acetaldehyde. An all atom model for the acetaldehyde have been optimized in the present work. Theoretical values obtained for heat of vaporisation and density of the liquid are in good agreement with experimental data. Graphics of radial distribution function indicate a well structured liquid compared to other similar dipolar organic liquids. Molecular mechanics minimization in gas phase leads to a trimer of very stable structure. The geometry of this complex is in very good agreement with the rdf. The shortest site-site correlation is between oxygen and the carbonyl hydrogen, suggesting that this correlation play a important role in the liquid structure and properties. The OxxxH average distance and the C-HxxxO angle obtained are characteristic of weak hydrogen bonds.

  7. Hydrogen adsorption in metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Senkovska, Irena; Kaskel, Stefan [Department of Inorganic Chemistry, Technical University, Dresden (Germany)

    2008-07-01

    Metal-Organic Frameworks (MOFs) have recently received considerable attention because of their high specific micropore volume and the ability to store gas molecules exceeding the storage capacity of traditional adsorbents. A variety of differences in the MOFs structures makes it difficult to analyze the influence of different factors on hydrogen uptake capabilities in MOFs. We have investigated the influence of the minor structural changes of the MOFs on their hydrogen storage capacity. The influence of the incorporated metal was shown for following isostructural compounds: Cu{sub 3}(BTC){sub 2} (BTC=1,3,5-benzenetricarboxylate) and Mo{sub 3}(BTC){sub 2}; Zn{sub 2}(BDC){sub 2}DABCO and Co{sub 2}(BDC){sub 2}DABCO (BDC=1,4-benzenedicarboxylate, DABCO=1,4-diazabicyclo[2.2.2]octane). Our research interest is directed also towards the discovery of new MOFs, as well as adjusting the pore dimensions of MOFs, using different building blocks, solvent and solvent mixtures, in order to improve gas uptake and adsorption properties. Magnesium-based MOFs were found with the same network topology, very small pore size and selective adsorption behaviour. They show a guest-induced reversible structure transformation due to the flexibility of the Mg{sub 3}-cluster and the organic linkers. This effect could be used for fitting the pore sizes and for the increase of gas sorption capability in Mg contained MOFs after all. The hydrogen adsorption was also studied in several Al-based IRMOFs.

  8. Hydrogen absorption-desorption at metal surfaces

    International Nuclear Information System (INIS)

    Ward, C.A.; Pataki, L.

    1991-04-01

    On the basis of experimental studies, it has been proposed that when zirconium oxide (ZrO 2 ) is exposed to hydrogen at 300 degrees C or higher, a reaction occurs to produce metallic zirconium and water, thereby increasing the electrical conductivity of the oxide film and its permeability to hydrogen. A series of experiments has been performed in which specimens of zirconium and zirconium-2.5% niobium were either hydrided or deuterided in a furnace at a temperature between 300 degrees C and 800 degrees C and in an atmosphere that consisted primarily of either hydrogen (H 2 ) or deuterium (D 2 ). After cooling a specimen to room temperature, it was placed in a thermogravimetric analyzer that was equipped with a mass spectrometer, TGA-MS. Each specimen was then heated to 1200 degrees C at a controlled rate in a primarily helium atmosphere monitored with the mass spectrometer. Light water (H 2 O) evolved from the hydrided specimens and heavy water (D 2 0) from the deuterided ones and there was a weight loss of the specimens that accompanied the water evolution. The specimens having approximately the same amount of hydride but more oxide also evolved more H 2 O, and that the H 2 O did not come from reactions between impurity H 2 and oxygen (O 2 ) in the TGA-MS. Heating a zirconium or zirconium alloy specimen that contains a hydride or deuteride phase within and an oxide layer on its surface causes the hydrogen to diffuse toward the surface and when it encounters the oxide a reaction follows that produces water. The conventional mechanism for the dissipation of the imperviousness of ZrO 2 to H 2 that results from the oxide being exposed to a reducing atmosphere will not explain the water production observed in these experiments. However, the existence of the proposed reaction can account for the elevated hydrogen concentration in an oxide film that has been observed to accompany the aqueous corrosion of zirconium and the effects on both the electrical conductivity and

  9. First-row transition metal hydrogenation and hydrosilylation catalysts

    Science.gov (United States)

    Trovitch, Ryan J.; Mukhopadhyay, Tufan K.; Pal, Raja; Levin, Hagit Ben-Daat; Porter, Tyler M.; Ghosh, Chandrani

    2017-07-18

    Transition metal compounds, and specifically transition metal compounds having a tetradentate and/or pentadentate supporting ligand are described, together with methods for the preparation thereof and the use of such compounds as hydrogenation and/or hydrosilylation catalysts.

  10. Performance of metallic fuels in liquid-metal fast reactors

    International Nuclear Information System (INIS)

    Seidel, B.R.; Walters, L.C.; Kittel, J.H.

    1984-01-01

    Interest in metallic fuels for liquid-metal fast reactors has come full circle. Metallic fuels are once again a viable alternative for fast reactors because reactor outlet temperature of interest to industry are well within the range where metallic fuels have demonstrated high burnup and reliable performance. In addition, metallic fuel is very tolerant of off-normal events of its high thermal conductivity and fuel behavior. Futhermore, metallic fuels lend themselves to compact and simplified reprocessing and refabrication technologies, a key feature in a new concept for deployment of fast reactors called the Integral Fast Reactor (IFR). The IFR concept is a metallic-fueled pool reactor(s) coupled to an integral-remote reprocessing and fabrication facility. The purpose of this paper is to review recent metallic fuel performance, much of which was tested and proven during the twenty years of EBR-II operation

  11. Recycling of Metal Containing Waste by Liquid-Liquid Extraction

    International Nuclear Information System (INIS)

    Reinhardt, H.

    1999-01-01

    Through the years, a large number of liquid-liquid extraction have been proposed for metal waste recovery and recycling(1,2). However, few of them have achieved commercial application. In fact, relatively little information is available on practical operation and economic feasibility. This presentation will give complementary information by describing and comparing three processes, based on the Am MAR hydrometallurgical concept and representing three different modes of operation

  12. Novel catalysts for isotopic exchange between hydrogen and liquid water

    International Nuclear Information System (INIS)

    Butler, J.P.; Rolston, J.H.; Stevens, W.H.

    1978-01-01

    Catalytic isotopic exchange between hydrogen and liquid water offers many inherent potential advantages for the separation of hydrogen isotopes which is of great importance in the Canadian nuclear program. Active catalysts for isotopic exchange between hydrogen and water vapor have long been available, but these catalysts are essentially inactive in the presence of liquid water. New, water-repellent platinum catalysts have been prepared by: (1) treating supported catalysts with silicone, (2) depositing platinum on inherently hydrophobic polymeric supports, and (3) treating platinized carbon with Teflon and bonding to a carrier. The activity of these catalysts for isotopic exchange between countercurrent streams of liquid water and hydrogen saturated with water vapor has been measured in a packed trickle bed integral reactor. The performance of these hydrophobic catalysts is compared with nonwetproofed catalysts. The mechanism of the overall exchange reaction is briefly discussed. 6 figures

  13. The liquid hydrogen cell in the EL3 Saclay reactor; Cellule a hydrogene liquide dans la pile EL3 de Saclay

    Energy Technology Data Exchange (ETDEWEB)

    Jacrot, B; Lacaze, A; Weil, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; [Grenoble-1 Univ., 38 (France)

    1960-07-01

    Description and results in connection with the liquid hydrogen cell, for obtaining slow neutrons, in the EL3. (author) [French] Description et resultats concernant la cellule a hydrogene liquide de EL3 utilisee pour obtenir des neutrons lents. (auteur)

  14. Acoustically Forced Coaxial Hydrogen / Liquid Oxygen Jet Flames

    Science.gov (United States)

    2016-05-15

    Conference Paper 3. DATES COVERED (From - To) 18 Mar 2016 – 15 May 2016 4. TITLE AND SUBTITLE Acoustically Forced Coaxial Hydrogen / Liquid Oxygen Jet...perform, display, or disclose the work. 13. SUPPLEMENTARY NOTES For presentation at 28th Annual Conference on Liquid Atomization and Spray Systems...serious problems in the development of liquid rocket engines. In order to understand and predict them, it is necessary to understand how representative

  15. Two-dimensional metal dichalcogenides and oxides for hydrogen evolution

    DEFF Research Database (Denmark)

    Pandey, Mohnish; Vojvodic, Aleksandra; Thygesen, Kristian Sommer

    2015-01-01

    We explore the possibilities of hydrogen evolution by basal planes of 2D metal dichalcogenides and oxides in the 2H and 1T class of structures using the hydrogen binding energy as a computational activity descriptor. For some groups of systems like the Ti, Zr, and Hf dichalcogenides the hydrogen...

  16. Liquid metal degassing in electromagnetic mixing

    Energy Technology Data Exchange (ETDEWEB)

    Pakhomov, A I; EHL' -FAVAKHRI, KAMAL' -ABD-RABU MOKHAMED [LENINGRADSKIJ POLITEKHNICHESKIJ INST. (USSR)

    1977-01-01

    Experimental results for laboratory and industrial conditions are presented showing the favourable effect of electromagnetic mixing on hot metal degassing process. It has been found that the intensity and duration of the mixing process increase with the degree of iron and steel degassing. Initiation of cavitation phenomena during hot metal electromagnetic mixing is intensified because of the presence of alien inclusions in the metal reducing the tensile strength of the liquid metal. This is the most substantial factor contributing to the gas content in the process of electromagnetic mixing.

  17. Radiative proton-capture nuclear processes in metallic hydrogen

    International Nuclear Information System (INIS)

    Ichimaru, Setsuo

    2001-01-01

    Protons being the lightest nuclei, metallic hydrogen may exhibit the features of quantum liquids most relevant to enormous enhancement of nuclear reactions; thermonuclear and pycnonuclear rates and associated enhancement factors of radiative proton captures of high-Z nuclei as well as of deuterons are evaluated. Atomic states of high-Z impurities are determined in a way consistent with the equations of state and screening characteristics of the metallic hydrogen. Rates of pycnonuclear p-d reactions are prodigiously high at densities ≥20 g/cm 3 , pressures ≥1 Gbar, and temperatures ≥950 K near the conditions of solidification. It is also predicted that proton captures of nuclei such as C, N, O, and F may take place at considerable rates, owing to strong screening by K-shell electrons, if the densities ≥60-80 g/cm 3 , the pressures ≥7-12 Gbar, and the temperatures just above solidification. The possibilities and significance of pycnonuclear p-d fusion experiments are specifically remarked

  18. Liquid metal flow measurement by neutron radiography

    International Nuclear Information System (INIS)

    Takenaka, N.; Ono, A.; Matsubayashi, M.; Tsuruno, A.

    1996-01-01

    Visualization of a liquid metal flow and image processing methods to measure the vector field are carried out by real-time neutron radiography. The JRR-3M real-time thermal neutron radiography facility in the Japan Atomic Energy Research Institute was used. Lead-bismuth eutectic was used as a working fluid. Particles made from a gold-cadmium intermetallic compound (AuCd 3 ) were used as the tracer for the visualization. The flow vector field was obtained by image processing methods. It was shown that the liquid metal flow vector field was obtainable by real-time neutron radiography when the attenuation of neutron rays due to the liquid metal was less than l/e and the particle size of the tracer was larger than one image element size digitized for the image processing. (orig.)

  19. Hydrogen extraction from liquid lithium-lead alloy by gas-liquid contact method

    International Nuclear Information System (INIS)

    Xie Bo; Weng Kuiping; Hou Jianping; Yang Guangling; Zeng Jun

    2013-01-01

    Hydrogen extraction experiment from liquid lithium-lead alloy by gas-liquid contact method has been carried out in own liquid lithium-lead bubbler (LLLB). Experimental results show that, He is more suitable than Ar as carrier gas in the filler tower. The higher temperature the tower is, the greater hydrogen content the tower exports. Influence of carrier gas flow rate on the hydrogen content in the export is jagged, no obvious rule. Although the difference between experimental results and literature data, but it is feasible that hydrogen isotopes extraction experiment from liquid lithium-lead by gas-liquid contact method, and the higher extraction efficiency increases with the growth of the residence time of the alloy in tower. (authors)

  20. Hydrogen storage by organic chemical hydrides and hydrogen supply to fuel cells with superheated liquid-film-type catalysis

    International Nuclear Information System (INIS)

    Hodoshima, S.; Shono, A.; Sato, K.; Saito, Y.

    2004-01-01

    Organic chemical hydrides, consisting of decalin / naphthalene and tetralin / naphthalene pairs, have been proposed as the storage medium of hydrogen for operating fuel cells in mobile and static modes. The target values in the DOE Hydrogen Plan, U.S., on storage ( 6.5 wt%, 62.0 kg-H 2 / m 3 ) are met with decalin ( 7.3 wt%, 64.8 kg-H 2 / m 3 ). In addition, existing gas stations and tank lorries are available for storage and supply of hydrogen by utilizing the decalin / naphthalene pair, suggesting that decalin is suitable for operating fuel-cell vehicles. Tetralin dehydrogenation proceeds quite rapidly, assuring a predominant power density, though its storage densities ( 3.0 wt%, 28.2 kg-H 2 / m 3 ) are relatively low. Efficient hydrogen supply from decalin or tetralin by heating at 210-280 o C was attained only with the carbon-supported nano-size metal catalysts in the 'superheated liquid-film states' under reactive distillation conditions, where coke formation over the catalyst surface was prevented. The catalyst layer superheated in the liquid-film states gave high reaction rates and conversions, minimizing the evaporation loss under boiling conditions and exergy loss in hydrogen energy systems. (author)

  1. Detection of hydrogen buildup in initially pure nonhydrogenous liquids

    International Nuclear Information System (INIS)

    McNeany, S.R.; Jenkins, J.D.

    1978-12-01

    A technique for monitoring hydrogen buildup in initially pure nonhydrogenous liquids is described in this report. The detection method is based upon the neutron-moderating properties of hydrogen. The analysis leading to the selection and design of a hydrogen-monitoring device is described. An experimental mockup of the device was then constructed and tested for hydrogen sensitivity. A hot cell was used for these tests. A device proved capable of measuring hydrogen concentrations in the range of 0 to 13.0 x 10 27 atoms/m 3 , with an accuracy of about 1.0 x 10 27 atoms/m 3 . A typical measurement can be made in 3 to 5 min. The experimental results confirmed the sensitivities predicted by the analysis and demonstrated that such a device would be practical for hydrogen concentration measurements for criticality control in an HTGR fuel refabrication plant

  2. Dynamic Compression Experiments on Hydrogen and Deuterium in the Warm Dense Liquid.

    Science.gov (United States)

    Desjarlais, Michael; McCoy, Chad; Cochrane, Kyle; Mattsson, Thomas; Knudson, Marcus; Redmer, Ronald

    2017-06-01

    Recently a shock-ramp platform has been developed on the Z Accelerator to access off-Hugoniot states in liquids. The accelerator delivers a two-step current pulse; the first accelerates the electrode to a constant velocity, which upon impact with the sample cell creates a well-defined shock, the subsequent current rise produces ramp compression from the initially shocked state producing relatively cool (1-2 kK), high pressure (>300 GPa), high compression (10 to 15-fold compression) states. This technique allows experimental access to the region of phase space where hydrogen is predicted to undergo a first-order phase transition from an insulating molecular-like to a conducting atomic-like liquid. Here we discuss the experimental platform, survey various theoretical predictions for the liquid-liquid, insulator-to-metal transition in hydrogen, and present results of experiments on both deuterium and hydrogen that clearly show an abrupt transition to a metallic state. We also present results from recent experiments at higher temperatures (3-4 kK) and compare the observations to both first-principles theory and previous step-wise loading experiments that exhibited a minimum metallic conductivity. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  3. Clad buffer rod sensors for liquid metals

    International Nuclear Information System (INIS)

    Jen, C.-K.; Ihara, I.

    1999-01-01

    Clad buffer rods, consisting of a core and a cladding, have been developed for ultrasonic monitoring of liquid metal processing. The cores of these rods are made of low ultrasonic-loss materials and the claddings are fabricated by thermal spray techniques. The clad geometry ensures proper ultrasonic guidance. The lengths of these rods ranges from tens of centimeters to 1m. On-line ultrasonic level measurements in liquid metals such as magnesium at 700 deg C and aluminum at 960 deg C are presented to demonstrate their operation at high temperature and their high ultrasonic performance. A spherical concave lens is machined at the rod end for improving the spatial resolution. High quality ultrasonic images have been obtained in the liquid zinc at 600 deg C. High spatial resolution is needed for the detection of inclusions in liquid metals during processing. We also show that the elastic properties such as density, longitudinal and shear wave velocities of liquid metals can be measured using a transducer which generates and receives both longitudinal and shear waves and is mounted at the end of a clad buffer rod. (author)

  4. Liquid metal cooled fast breeder nuclear reactor

    International Nuclear Information System (INIS)

    Scott, D.

    1979-01-01

    A liquid metal cooled fast breeder nuclear reactor has a core comprising a plurality of fuel assemblies supported on a diagrid and submerged in a pool of liquid metal coolant within a containment vessel, the diagrid being of triple component construction and formed of a short cylindrical plenum mounted on a conical undershell and loosely embraced by a fuel store carrier. The plenum merely distributes coolant through the fuel assemblies, the load of the assemblies being carried by the undershell by means of struts which penetrate the plenum. The reactor core, fuel store carrier and undershell provide secondary containment for the plenum. (UK)

  5. Some Issues in Liquid Metals Research

    Directory of Open Access Journals (Sweden)

    Maria José Caturla

    2015-11-01

    Full Text Available The ten articles [1–10] included in this Special Issue on “Liquid Metals” do not intend to comprehensively cover this extensive field, but, rather, to highlight recent discoveries that have greatly broadened the scope of technological applications of these materials. Improvements in understanding the physics of liquid metals are, to a large extent, due to the powerful theoretical tools in the hands of scientists, either semi-empirical [1,5,6] or ab initio (molecular dynamics, see [7]. Surface tension and wetting at metal/ceramic interfaces is an everlasting field of fundamental research with important technological implications. The review of [2] is broad enough, as the work carried out at Grenoble covers almost all interesting matters in the field. Some issues of interest in geophysics and astrophysics are discussed in [3]. The recently discovered liquid–liquid transition in several metals is dealt with in [4]. The fifth contribution [5] discusses the role of icosahedral superclusters in crystallization. In [6], thermodynamic calculations are carried out to identify the regions of the ternary phase diagram of Al-Cu-Y, where the formation of amorphous alloys is most probable. Experimental data and ab initio calculations are presented in [7] to show that an optimal microstructure is obtained if Mg is added to the Al-Si melt before than the modifier AlP alloy. Shock-induced melting of metals by means of laser driven compression is discussed in [8]. With respect to recent discoveries, one of the most outstanding developments is that of gallium alloys that are liquid at room temperature [9], and that, due to the oxide layer that readily cover their surface, maintain some “stiffness”. This has opened the possibility of 3D printing with liquid metals. The last article in this Special Issue [10] describes nano-liquid metals, a suspension of liquid metal and its alloy containing nanometer-sized particles. A room-temperature nano-liquid metal

  6. Properties of structural materials in liquid metal environment

    International Nuclear Information System (INIS)

    Borgstedt, H.U.

    1991-12-01

    The proceedings contain 16 contributions to the following topics: 1. Creep-Rupture Behaviour of Structural Materials in Liquid Metal Environment; 2. Behaviour of Materials in Liquid Metal Environment under Off-Normal Conditions; 3. Fatigue and Creep-Fatigue of Structural Materials in Liquid Metal Environment; and 4. Crack Propagation in Liquid Sodium. (MM)

  7. Oxidation-Mediated Fingering in Liquid Metals

    Science.gov (United States)

    Eaker, Collin B.; Hight, David C.; O'Regan, John D.; Dickey, Michael D.; Daniels, Karen E.

    2017-10-01

    We identify and characterize a new class of fingering instabilities in liquid metals; these instabilities are unexpected due to the large interfacial tension of metals. Electrochemical oxidation lowers the effective interfacial tension of a gallium-based liquid metal alloy to values approaching zero, thereby inducing drastic shape changes, including the formation of fractals. The measured fractal dimension (D =1.3 ±0.05 ) places the instability in a different universality class than other fingering instabilities. By characterizing changes in morphology and dynamics as a function of droplet volume and applied electric potential, we identify the three main forces involved in this process: interfacial tension, gravity, and oxidative stress. Importantly, we find that electrochemical oxidation can generate compressive interfacial forces that oppose the tensile forces at a liquid interface. The surface oxide layer ultimately provides a physical and electrochemical barrier that halts the instabilities at larger positive potentials. Controlling the competition between interfacial tension and oxidative (compressive) stresses at the interface is important for the development of reconfigurable electronic, electromagnetic, and optical devices that take advantage of the metallic properties of liquid metals.

  8. Task-specific ionic liquids for solubilizing metal compounds

    OpenAIRE

    Thijs, Ben

    2007-01-01

    The main goal of this PhD thesis was to design new task-specific ionic liquids with the ability to dissolve metal compounds. Despite the large quantity of papers published on ionic liquids, not much is known about the mechanisms of dissolving metals in ionic liquids or about metal-containing ionic liquids. Additionally, many of the commercially available ionic liquids exhibit a very limited solubilizing power for metal compounds, although this is for many applications like electrodeposition a...

  9. Liquid-phase chemical hydrogen storage: catalytic hydrogen generation under ambient conditions.

    Science.gov (United States)

    Jiang, Hai-Long; Singh, Sanjay Kumar; Yan, Jun-Min; Zhang, Xin-Bo; Xu, Qiang

    2010-05-25

    There is a demand for a sufficient and sustainable energy supply. Hence, the search for applicable hydrogen storage materials is extremely important owing to the diversified merits of hydrogen energy. Lithium and sodium borohydride, ammonia borane, hydrazine, and formic acid have been extensively investigated as promising hydrogen storage materials based on their relatively high hydrogen content. Significant advances, such as hydrogen generation temperatures and reaction kinetics, have been made in the catalytic hydrolysis of aqueous lithium and sodium borohydride and ammonia borane as well as in the catalytic decomposition of hydrous hydrazine and formic acid. In this Minireview we briefly survey the research progresses in catalytic hydrogen generation from these liquid-phase chemical hydrogen storage materials.

  10. The kinetics of hydrogen removal from liquid sodium

    International Nuclear Information System (INIS)

    Gwyther, J.R.; Whittingham, A.C.

    1981-01-01

    The rates of hydrogen removal from liquid sodium-sodium hydride mixtures have been measured as a function of sodium stirring rate at temperatures up to 420 0 C. Two techniques have been employed - removal under continuous evacuation in which hydrogen flow rates were measured using a capillary flow technique and by argon purging in which hydrogen concentrations in the argon carrier gas were measured by gas chromatography. The results have been used to assess the feasibility of thermal decomposition of sodium hydride for the regeneration of hydride-laden LMFBR cold traps. Studies on the kinetics of desorption of hydrogen from solution in liquid sodium at temperatures up to 400 0 C are also presented and possible kinetic mechanisms discussed. (orig.)

  11. Liquid hydrogen production and economics for NASA Kennedy Space Center

    Science.gov (United States)

    Block, D. L.

    1985-12-01

    Detailed economic analyses for the production of liquid hydrogen used to power the Space Shuttle are presented. The hydrogen production and energy needs of the NASA Kennedy Space Center are reviewed, and steam reformation, polygeneration, and electrolysis for liquid hydrogen production are examined on an equal economic basis. The use of photovoltaics as an electrolysis power source is considered. The 1985 present worth is calculated based on life cycle costs over a 21-year period beginning with full operation in 1990. Two different sets of escalation, inflation, and discount rates are used, with revenue credit being given for energy or other products of the hydrogen production process. The results show that the economic analyses are very dependent on the escalation rates used. The least net present value is found for steam reformation of natural gas, while the best net present value is found for the electrolysis process which includes the phasing of photovoltaics.

  12. Liquid metal cooled fast breeder nuclear reactors

    International Nuclear Information System (INIS)

    Durston, J.G.

    1976-01-01

    It is stated that in a liquid metal cooled fast breeder reactor wherein the core, intermediate heat exchangers and liquid metal pumps are immersed in a pool of coolant such as Na, the intermediate heat exchangers are suspended from the roof, and ducting is provided in the form of a core tank or shroud interconnected with 'pods' housing the intermediate exchangers for directing coolant from the core over the heat exchanger tubes and thence back to the main pool of liquid metal. Seals are provided between the intermediate heat exchanger shells and the walls of their 'pods' to prevent liquid metal flow by-passing the heat exchanger tube bundles. As the heat exchangers must be withdrawable for servicing, and because linear differential thermal expansion of the heat exchanger and its 'pod' must be accommodated the seals hitherto have been of the sliding kind, generally known as 'piston ring type seals'. These present several disadvantages; for example sealing is not absolute, and the metal to metal seal gives rise to wear and fretting by rubbing and vibration. This could lead to seizure or jamming by the deposition of impurities in the coolant. Another difficulty arises in the need to accommodate lateral thermal expansion of the ducting, including the core tank and 'pods'. Hitherto some expansion has been allowed for by the use of expansible bellow pairs in the interconnections, or alternatively by allowing local deformations of the core tank 'pods'. Such bellows must be very flexible and hence constitute a weak section of the ducting, and local deformations give rise to high stress levels that could lead to premature failure. The arrangement described seeks to overcome these difficulties by use of a gas pocket trapping means to effect a seal against vertical liquid flow between the heat exchanger shell and the wall of the heat exchanger housing. Full details of the arrangement are described. (U.K.)

  13. The reactions of oxygen and hydrogen with liquid sodium

    International Nuclear Information System (INIS)

    Ullmann, H.

    1981-01-01

    Results so far available as to the reactions and chemical equilibrium of oxygen and hydrogen with liquid sodium have been analyzed critically. The enthalpy values of the reactions have been discussed and supplemented on the basis of corresponding BORN-HABER cycles. The concentration and temperature functions of the hydrogen equilibrium pressure were deduced from experimental results. In relation to the solubility data the solid phases coexisting with liquid sodium in the ternary system Na-O-H have been discussed. The reaction of oxygen with hydrogen in diluted solution in liquid sodium has been investigated in more detail. Interaction coefficients, and the temperature functions of the free energy of formation and the equilibrium constant have been determined. (orig.)

  14. Liquid and Solid Metal Embrittlement.

    Science.gov (United States)

    1981-09-05

    example, embrittlement of AISI 4140 steel begins at T/T, - 0.75 for cadmium, and 0.85 for lead and tin environments (2). In a few cases, e.g. zinc...has recently proposed, however, that liquid zinc can penetrate to very near the tip of a sharp crack in 4140 steel, based upon both direct observation...long could be detected, was observed in delayed failure experi- ments on unnotched 4140 steel, in the quenched and tempered condi- tion, embrittled by

  15. Hydrogenation of liquid natural rubber via diimide reduction in hydrazine hydrate/hydrogen peroxide system

    International Nuclear Information System (INIS)

    Yusof, Muhammad Jefri Mohd; Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

    2015-01-01

    Liquid natural rubber (LNR) with molecular weight of lower than 10 5 and shorter polymeric chain than natural rubber was prepared. LNR was then hydrogenated via diimide reduction by oxidation of hydrazine hydrate with hydrogen peroxide. The unsaturated units of the rubber were converted into saturated hydrocarbon to strengthen the backbone of the polymer so it was able to resist thermal degradation. The results indicated that hydrogenation degree of the product (HLNR) could be extended to 91.2% conversion under appropriate conditions. The hydrogenated LNR (HLNR) was characterized using Fourier-Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The physical characteristics of HLNR were analyzed with Termogravimetric Analysis (TGA)

  16. Hydrogenation of liquid natural rubber via diimide reduction in hydrazine hydrate/hydrogen peroxide system

    Science.gov (United States)

    Yusof, Muhammad Jefri Mohd; Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

    2015-09-01

    Liquid natural rubber (LNR) with molecular weight of lower than 105 and shorter polymeric chain than natural rubber was prepared. LNR was then hydrogenated via diimide reduction by oxidation of hydrazine hydrate with hydrogen peroxide. The unsaturated units of the rubber were converted into saturated hydrocarbon to strengthen the backbone of the polymer so it was able to resist thermal degradation. The results indicated that hydrogenation degree of the product (HLNR) could be extended to 91.2% conversion under appropriate conditions. The hydrogenated LNR (HLNR) was characterized using Fourier-Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The physical characteristics of HLNR were analyzed with Termogravimetric Analysis (TGA).

  17. Hydrogenation of liquid natural rubber via diimide reduction in hydrazine hydrate/hydrogen peroxide system

    Energy Technology Data Exchange (ETDEWEB)

    Yusof, Muhammad Jefri Mohd; Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2015-09-25

    Liquid natural rubber (LNR) with molecular weight of lower than 10{sup 5} and shorter polymeric chain than natural rubber was prepared. LNR was then hydrogenated via diimide reduction by oxidation of hydrazine hydrate with hydrogen peroxide. The unsaturated units of the rubber were converted into saturated hydrocarbon to strengthen the backbone of the polymer so it was able to resist thermal degradation. The results indicated that hydrogenation degree of the product (HLNR) could be extended to 91.2% conversion under appropriate conditions. The hydrogenated LNR (HLNR) was characterized using Fourier-Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The physical characteristics of HLNR were analyzed with Termogravimetric Analysis (TGA)

  18. Liquid metal fast reactor transient design

    International Nuclear Information System (INIS)

    Horak, C.; Purvis, E. III

    2000-01-01

    An examination has been made of how the currently available computing capabilities could be used to reduce Liquid Metal Fast Reactor design, manufacturing, and construction cost. While the examination focused on computer analyses some other promising means to reduce costs were also examined. (author)

  19. Improvements in liquid metal cooled nuclear reactors

    International Nuclear Information System (INIS)

    Barnes, S.

    1980-01-01

    A concrete containment vault for a liquid metal cooled nuclear reactor is described which is lined with thermal insulation to protect the vault against heat radiated from the reactor during normal operation of the reactor but whose efficiency of heat insulation is reduced in an emergency to enable excessive heat from the reactor to be dissipated through the vault. (UK)

  20. PFR liquid metals disposal at Dounreay

    International Nuclear Information System (INIS)

    McIntyre, A.W.

    1997-01-01

    When the Prototype Fast Reactor (PFR) at Dounreay was shut down in 1994, the UKAEA commissioned a series of studies to determine the least cost, lowest risk option for dealing with the liquid metal coolants, i.e. the sodium from the primary and secondary circuits and the NaK from the decay heat removal system. The studies concluded that leaving the liquid metals in situ was not a viable option. Removing the liquid metals had three options, provision of long term external storage facilities, re-use in other projects or treatment for final disposal. The UKAEA invited companies to bid for the challenging task of disposing of more than 1500 t of liquid metals. In 1995 UKAEA awarded NNC Ltd. one of the largest decommissioning projects ever to be let competitively in the UK. During the first year of the contract, the challenges have focused on solving design problems and a number of innovative solutions have been developed by NNC and its subcontractors. From January 1997 the focus has moved to construction on site at Dounreay, and the manufacturing and installation of the mechanical components of the plant

  1. Improvements in liquid metal cooled nuclear reactors

    International Nuclear Information System (INIS)

    Barnes, S.

    1980-01-01

    Improvements in the design of the thermally insulating material used to shield the concrete containment walls in liquid metal cooled nuclear reactors are described in detail. The insulating material is composed of two layers and is placed between the primary vessel (usually steel) and the steel lined concrete containment vault. The outer layer, which clads the inner wall surface of the vault, is generally impervious to liquid metal coolant whilst the inner layer is pervious to the coolant. In normal operation, both layers protect the concrete from heat radiated from the reactor. In the event of a breach of the containment vessel, the resulting leakage of liquid metal coolant permeates the inner layer of insulating material, provides a means of heat transfer by conduction and hence reduces the overall insulating properties of the two layers. The outer layer continues to protect the wall surface of the vault from substantial direct contact with the liquid metal. Thus the two apparently conflicting requirements of good thermal insulation during normal operation and of heat transfer during loss of coolant accidents are satisfied by this novel design. Suggestions are given for possible materials for use as the insulating layers. (U.K.)

  2. Heat Analysis of Liquid piston Compressor for Hydrogen Applications

    DEFF Research Database (Denmark)

    Kermani, Nasrin Arjomand; Rokni, Masoud

    2014-01-01

    A new hydrogen compression technology using liquid as the compression piston is investigated from heat transfer point of view. A thermodynamic model, simulating a single compression stroke, is developed to investigate the heat transfer phenomena inside the compression chamber. The model is develo......A new hydrogen compression technology using liquid as the compression piston is investigated from heat transfer point of view. A thermodynamic model, simulating a single compression stroke, is developed to investigate the heat transfer phenomena inside the compression chamber. The model...

  3. Track formation in a liquid hydrogen ultrasonic bubble chamber

    CERN Document Server

    Brown, R C A; Jarman, P D

    1973-01-01

    Track sensitivity to minimum ionising particles has been demonstrated in liquid hydrogen using only an intense ultrasonic field. Carefully designed transducer systems are shown to be capable of producing pressure amplitudes >2.8 atm in a standing wave system in liquid hydrogen. The growth of bubbles to visible size (0.1 mm) in less than 0.2 ms, and their collapse in less than 15 ms, indicates that rapid cycling rates of 50-100 pulses per second may be feasible with this technique. (11 refs).

  4. Solubility of hydrogen isotopes in liquid LiPb

    International Nuclear Information System (INIS)

    Konishi, S.; Yamamoto, Y.; Noborio, K.; Calderoni, P.; Merrill, B.

    2014-01-01

    This research was performed mainly in the first half of the task 1-2 of TITAN project to investigate the interaction between hydrogen isotopes and liquid LiPb. Solubility of hydrogen in liquid LiPb was measured under a static condition. Kyoto University provided the first experimental apparatus shipped to Idaho, and Kyushu University succeeded the experiment and further improved. Obtained solubility generally agreed with some previous reports, but varied orders of magnitudes suggesting influence of impurity or other chemical processes. (author)

  5. Corrosion behavior of construction materials for ionic liquid hydrogen compressor

    DEFF Research Database (Denmark)

    Arjomand Kermani, Nasrin; Petrushina, Irina; Nikiforov, Aleksey Valerievich

    2016-01-01

    The corrosion behavior of various commercially available stainless steels and nickel-based alloys as possible construction materials for components which are in direct contact with one of five different ionic liquids was evaluated. The ionic liquids, namely: 1-ethyl-3-methylimidazolium triflate, 1...... liquid hydrogen compressor. An electrochemical cell was specially designed, and steady-state cyclic voltammetry was used to measure the corrosion resistance of the alloys in the ionic liquids at 23 °C, under atmospheric pressure. The results showed a very high corrosion resistance and high stability...... for all the alloys tested. The two stainless steels, AISI 316L and AISI 347 showed higher corrosion resistance compared to AISI 321 in all the ionic liquids tested. It was observed that small addition of molybdenum, tantalum, and niobium to the alloys increased the corrosion stability in the ionic liquids...

  6. Compact device to heat up a liquid metal

    International Nuclear Information System (INIS)

    Blanc, R.; Pelloux, L.

    1981-01-01

    Device for heating a liquid metal, sodium for instance, this device being in one piece and capable of being introduced in one go into the tank containing the liquid metal and comprising heating rods and an electromagnetic pump [fr

  7. Modeling liquid hydrogen cavitating flow with the full cavitation model

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.B.; Qiu, L.M.; Qi, H.; Zhang, X.J.; Gan, Z.H. [Institute of Refrigeration and Cryogenic Engineering, Zhejiang University, Hangzhou 310027 (China)

    2008-12-15

    Cavitation is the formation of vapor bubbles within a liquid where flow dynamics cause the local static pressure to drop below the vapor pressure. This paper strives towards developing an effective computational strategy to simulate liquid hydrogen cavitation relevant to liquid rocket propulsion applications. The aims are realized by performing a steady state computational fluid dynamic (CFD) study of liquid hydrogen flow over a 2D hydrofoil and an axisymmetric ogive in Hord's reports with a so-called full cavitation model. The thermodynamic effect was demonstrated with the assumption of thermal equilibrium between the gas phase and liquid phase. Temperature-dependent fluid thermodynamic properties were specified along the saturation line from the ''Gaspak 3.2'' databank. Justifiable agreement between the computed surface pressure, temperature and experimental data of Hord was obtained. Specifically, a global sensitivity analysis is performed to examine the sensitivity of the turbulent computations to the wall grid resolution, wall treatments and changes in model parameters. A proper near-wall model and grid resolution were suggested. The full cavitation model with default model parameters provided solutions with comparable accuracy to sheet cavitation in liquid hydrogen for the two geometries. (author)

  8. A method of measuring a molten metal liquid pool volume

    Science.gov (United States)

    Garcia, G.V.; Carlson, N.M., Donaldson, A.D.

    1990-12-12

    A method of measuring a molten metal liquid pool volume and in particular molten titanium liquid pools, including the steps of (a) generating an ultrasonic wave at the surface of the molten metal liquid pool, (b) shining a light on the surface of a molten metal liquid pool, (c) detecting a change in the frequency of light, (d) detecting an ultrasonic wave echo at the surface of the molten metal liquid pool, and (e) computing the volume of the molten metal liquid. 3 figs.

  9. Turbulent Liquid Metal Dynamo Experiments

    International Nuclear Information System (INIS)

    Forest, Cary

    2007-01-01

    The self-generation of magnetic fields in planets and stars--the dynamo effect--is a long-standing problem of magnetohydrodynamics and plasma physics. Until recently, research on the self-excitation process has been primarily theoretical. In this talk, I will begin with a tutorial on how magnetic fields are generated in planets and stars, describing the 'Standard Model' of self-excitation known as the alpha-omega dynamo. In this model, axisymmetric differential rotation can produce the majority of the magnetic field, but some non-axisymmetric, turbulence driven currents are also necessary. Understanding the conversion of turbulent kinetic energy in the fluid motion into electrical currents and thus magnetic fields, is a major challenge for both experiments and theory at this time. I will then report on recent results from a 1 meter diameter, spherical, liquid sodium dynamo experiment at the University of Wisconsin, in which the first clear evidence for these turbulence driven currents has been observed.

  10. Chemistry of liquid metal coolants and sensors

    International Nuclear Information System (INIS)

    Gnanasekaran, T.

    2015-01-01

    Liquid sodium is the coolant of choice for the current generation fast breeder reactors. When sodium contains low levels of dissolved non-metallic impurities, it is highly compatible with structural steels. When the dissolved oxygen level is high, corrosion and mass transfer in sodium-steel circuits are enhanced and this involves formation of NaxMyOz type of species (M = alloying components in steels). Experience has shown that this enhancement of corrosion in a sodium circuit with all austenitic steel structural materials would not be encountered if oxygen level in sodium is below ~ 5ppm. For understanding this observation, a complete knowledge on the phase diagrams of Na-M-O systems and the thermochemical data of all relevant NaxMyOz compounds is essential. This presentation would highlight the work carried out at IGCAR on the chemistry of liquid sodium and heavy liquid metal coolants. Work carried out on various sensors for their use in these liquid metal circuits would be described and their current status would be discussed

  11. Ionic Liquids as Extraction Media for Metal Ions

    Science.gov (United States)

    Hirayama, Naoki

    In solvent extraction separation of metal ions, recently, many researchers have investigated possible use of hydrophobic ionic liquids as extraction media instead of organic solvents. Ionic liquids are salts of liquid state around room temperature and can act not only as solvents but also as ion-exchangers. Therefore, the extraction mechanism of metal ions into ionic liquids is complicated. This review presents current overview and perspective on evaluation of nature of hydrophobic ionic liquids as extraction media for metal ions.

  12. Proton conducting ceramics for potentiometric hydrogen sensors for molten metals

    Energy Technology Data Exchange (ETDEWEB)

    Borland, H.; Llivina, L.; Colominas, S.; Abellà, J., E-mail: jordi.abella@iqs.edu

    2013-10-15

    Highlights: • Synthesis and chemical characterization of proton conductor ceramics. • Qualification of ceramics for hydrogen sensors in molten lithium–lead. • Ceramics have well-defined grains with a wide distribution of sizes. • Good agreement with predictions obtained with BaZrY, BaCeZrY and SrFeCo ceramics. -- Abstract: Tritium monitoring in lithium–lead eutectic (Pb–15.7Li) is of great importance for the performance of liquid blankets in fusion reactors. Also, tritium measurements will be required in order to proof tritium self-sufficiency in liquid metal breeding systems. On-line hydrogen (isotopes) sensors must be design and tested in order to accomplish these goals. Potentiometric hydrogen sensors for molten lithium–lead eutectic have been designed at the Electrochemical Methods Lab at Institut Quimic de Sarria (IQS) at Barcelona and are under development and qualification. The probes are based on the use of solid state electrolytes and works as proton exchange membranes (PEM). In this work the following compounds: BaZr{sub 0.9}Y{sub 0.1}O{sub 3}, BaCe{sub 0.6}Zr{sub 0.3}Y{sub 0.1}O{sub 3−α}, Sr(Ce{sub 0.6}-Zr{sub 0.4}){sub 0.9}Y{sub 0.1}O{sub 3−α} and Sr{sub 3}Fe{sub 1.8}Co{sub 2}O{sub 7} have been synthesized in order to be tested as PEM H-probes. Potentiometric measurements of the synthesized ceramic elements at 500 °C have been performed at a fixed hydrogen concentration. The sensors constructed using the proton conductor elements BaZr{sub 0.9}Y{sub 0.1}O{sub 3}, BaCe{sub 0.6}Zr{sub 0.3}Y{sub 0.1}O{sub 3−δ} and Sr{sub 3}Fe{sub 1.8}Co{sub 0.2}O{sub 7−δ} exhibited stable output potential and its value was close to the theoretical value calculated with the Nernst equation (deviation around 60 mV). In contrast, the sensor constructed using the proton conductor element Sr(Ce{sub 0.6}–Zr{sub 0.4}){sub 0.9}Y{sub 0.1}O{sub 3−δ} showed a deviation higher than 100 mV between experimental an theoretical data.

  13. Ground Operations Demonstration Unit for Liquid Hydrogen Initial Test Results

    Science.gov (United States)

    Notardonato, W. U.; Johnson, W. L.; Swanger, A. M.; Tomsik, T.

    2015-01-01

    NASA operations for handling cryogens in ground support equipment have not changed substantially in 50 years, despite major technology advances in the field of cryogenics. NASA loses approximately 50% of the hydrogen purchased because of a continuous heat leak into ground and flight vessels, transient chill down of warm cryogenic equipment, liquid bleeds, and vent losses. NASA Kennedy Space Center (KSC) needs to develop energy-efficient cryogenic ground systems to minimize propellant losses, simplify operations, and reduce cost associated with hydrogen usage. The GODU LH2 project has designed, assembled, and started testing of a prototype storage and distribution system for liquid hydrogen that represents an advanced end-to-end cryogenic propellant system for a ground launch complex. The project has multiple objectives including zero loss storage and transfer, liquefaction of gaseous hydrogen, and densification of liquid hydrogen. The system is unique because it uses an integrated refrigeration and storage system (IRAS) to control the state of the fluid. This paper will present and discuss the results of the initial phase of testing of the GODU LH2 system.

  14. A liquid hydrogen target for the calibration of the MEG and MEG II liquid xenon calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Signorelli, G., E-mail: giovanni.signorelli@pi.infn.it [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Baldini, A.M. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Bemporad, C.; Cei, F.; Nicolò, D. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Università di Pisa, Dipartimento di Fisica, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Galli, L.; Gallucci, G.; Grassi, M. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Papa, A. [Paul Scherrer Institut, 5232 Villigen (Switzerland); Sergiampietri, F. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Venturini, M. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa (Italy)

    2016-07-11

    We designed, built and operated a liquid hydrogen target for the calibration of the liquid xenon calorimeter of the MEG experiment. The target was used throughout the entire data taking period, from 2008 to 2013 and it is being refurbished and partly re-designed to be integrated and used in the MEG-II experiment.

  15. Comparison of alternate fuels for aircraft. [liquid hydrogen, liquid methane, and synthetic aviation kerosene

    Science.gov (United States)

    Witcofski, R. D.

    1979-01-01

    Liquid hydrogen, liquid methane, and synthetic aviation kerosene were assessed as alternate fuels for aircraft in terms of cost, capital requirements, and energy resource utilization. Fuel transmission and airport storage and distribution facilities are considered. Environmental emissions and safety aspects of fuel selection are discussed and detailed descriptions of various fuel production and liquefaction processes are given. Technological deficiencies are identified.

  16. Liquid-vapour surface sensors for liquid nitrogen and hydrogen

    Science.gov (United States)

    Siegwarth, J. D.; Voth, R. O.; Snyder, S. M.

    1992-01-01

    The present paper identifies devices to serve as liquid-vapor detectors in zero gravity. The testing in LH2 was done in a sealed glass Dewar system to eliminate any chance of mixing H2 and air. Most of the tests were performed with the leads to the sensor horizontal. Some results of rapid cycle testing of LVDG in LH2 are presented. Findings of rapid-cycle testing of LVDG in LH2 are discussed. The sensor crossed the liquid surface when the position sensor registered 1.9 V, which occurred at about 0.4075 s. The delay time was about 1.5 ms. From the estimated slope of the position sensor curve at 1.9 V, the velocity of the sensor through the liquid surface is over 3 m/s. Results of tests of optical sensors are presented as well.

  17. Surface studies of liquid metals and alloys

    International Nuclear Information System (INIS)

    Bastasz, Robert

    2003-01-01

    Liquid metals and alloys have been proposed for use in nuclear fusion reactors to serve as replaceable plasma-facing surfaces that remove particles and heat from reacting plasmas. Several materials are being considered for this purpose including lithium, gallium, and tin as well as some of the alloys made from these elements. In order to better understand the properties of liquid surfaces, the technique of low-energy ion scattering was used to examine the surface composition of several of these materials in vacuum as a function of temperature. Oxygen is found to rapidly segregate to the surface of several metallic liquids. The segregation process can be interpreted using a simple thermodynamic model based on Gibbs theory. In the case of an alloy of Sn and Li, Li also segregates to the liquid surface. This provides a means to produce a surface enriched in Li, which is more plasma compatible than Sn, without the need to handle large quantities of liquid Li. (author)

  18. A system of hydrogen powered vehicles with liquid organic hydrides

    International Nuclear Information System (INIS)

    Taube, M.

    1981-07-01

    A motor car system based on the hydrogen produced by nuclear power stations during the night in the summer, and coupled with organic liquid hydride seems to be a feasible system in the near future. Such a system is discussed and the cost is compared with gasoline. (Auth.)

  19. Solubilities of hydrogen and methane in coal liquids

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Ho-mu; Sebastian, H M; Simnick, J J; Chao, Kwang Chu

    1981-04-01

    The solubilities of hydrogen and methane in Exxon Donor Solvent (EDS) and Solvent Refined Coal II (SRC-II) coal liquids are determined at 190 and 270 C and pressures to 250 atm. Two narrow boiling distillate cuts from EDS and three from SRC-II are studied.

  20. Annihilation of antiprotons stopped in liquid hydrogen and deuterium

    International Nuclear Information System (INIS)

    Dalkarov, O.D.; Kerbikov, B.O.; Markushin, V.E.

    1976-01-01

    Detailed analysis is given of stopping antiproton annihilation in liquid hydrogen and deuterium. Connection between capture schedule and properties of bound states in nucleon-antinucleon system is established. The theoretical predictions are compared with experimental data which appeared in 1971-75

  1. Silicon surface barrier detectors used for liquid hydrogen density measurement

    Science.gov (United States)

    James, D. T.; Milam, J. K.; Winslett, H. B.

    1968-01-01

    Multichannel system employing a radioisotope radiation source, strontium-90, radiation detector, and a silicon surface barrier detector, measures the local density of liquid hydrogen at various levels in a storage tank. The instrument contains electronic equipment for collecting the density information, and a data handling system for processing this information.

  2. Microcomputer-aided monitor for liquid hydrogen target system

    International Nuclear Information System (INIS)

    Kitami, T.; Watanabe, K.

    1983-03-01

    A microcomputer-aided monitor for a liquid hydrogen target system has been designed and tested. Various kinds of input data such as temperature, pressure, vacuum, etc. are scanned in a given time interval. Variation with time in any four items can be displayed on CRT and, if neccessary, printed out on a sheet of recording paper. (author)

  3. Compact, Lightweight Electromagnetic Pump for Liquid Metal

    Science.gov (United States)

    Godfroy, Thomas; Palzin, Kurt

    2010-01-01

    A proposed direct-current electromagnetic pump for circulating a molten alkali metal alloy would be smaller and lighter and would demand less input power, relative to currently available pumps of this type. (Molten alkali metals are used as heat-transfer fluids in high-temperature stages of some nuclear reactors.) The principle of operation of this or any such pump involves exploitation of the electrical conductivity of the molten metal: An electric current is made to pass through the liquid metal along an axis perpendicular to the longitudinal axis of the flow channel, and a magnetic field perpendicular to both the longitudinal axis and the electric current is superimposed on the flowchannel region containing the electric current. The interaction between the electric current and the magnetic field produces the pumping force along the longitudinal axis. The advantages of the proposed pump over other such pumps would accrue from design features that address overlapping thermal and magnetic issues.

  4. Delayed neutrons in liquid metal spallation targets

    International Nuclear Information System (INIS)

    Ridikas, D.; Bokov, P.; David, J.C.; Dore, D.; Giacri, M.L.; Van Lauwe, A.; Plukiene, R.; Plukis, A.; Ignatiev, S.; Pankratov, D.

    2003-01-01

    The next generation spallation neutron sources, neutrino factories or RIB production facilities currently being designed and constructed around the world will increase the average proton beam power on target by a few orders of magnitude. Increased proton beam power results in target thermal hydraulic issues leading to new target designs, very often based on flowing liquid metal targets such as Hg, Pb, Pb-Bi. Radioactive nuclides produced in liquid metal targets are transported into hot cells, past electronics, into pumps with radiation sensitive components, etc. Besides the considerable amount of photon activity in the irradiated liquid metal, a significant amount of the delayed neutron precursor activity can be accumulated in the target fluid. The transit time from the front of a liquid metal target into areas, where delayed neutrons may be important, can be as short as a few seconds, well within one half-life of many delayed neutron precursors. Therefore, it is necessary to evaluate the total neutron flux (including delayed neutrons) as a function of time and determine if delayed neutrons contribute significantly to the dose rate. In this study the multi-particle transport code MCNPX combined with the material evolution program CINDER'90 will be used to evaluate the delayed neutron flux and spectra. The following scientific issues will be addressed in this paper: - Modeling of a typical geometry of the liquid metal spallation target; - Predictions of the prompt neutron fluxes, fission fragment and spallation product distributions; - Comparison of the above parameters with existing experimental data; - Time-dependent calculations of delayed neutron precursors; - Neutron flux estimates due to the prompt and delayed neutron emission; - Proposal of an experimental program to measure delayed neutron spectra from high energy spallation-fission reactions. The results of this study should be directly applicable in the design study of the European MegaPie (1 MW

  5. Liquid Metal Machine Triggered Violin-Like Wire Oscillator.

    Science.gov (United States)

    Yuan, Bin; Wang, Lei; Yang, Xiaohu; Ding, Yujie; Tan, Sicong; Yi, Liting; He, Zhizhu; Liu, Jing

    2016-10-01

    The first ever oscillation phenomenon of a copper wire embraced inside a self-powered liquid metal machine is discovered. When contacting a copper wire to liquid metal machine, it would be swallowed inside and then reciprocally moves back and forth, just like a violin bow. Such oscillation could be easily regulated by touching a steel needle on the liquid metal surface.

  6. Hydrogen evolution by a metal-free electrocatalyst

    KAUST Repository

    Zheng, Yao

    2014-04-28

    Electrocatalytic reduction of water to molecular hydrogen via the hydrogen evolution reaction may provide a sustainable energy supply for the future, but its commercial application is hampered by the use of precious platinum catalysts. All alternatives to platinum thus far are based on nonprecious metals, and, to our knowledge, there is no report about a catalyst for electrocatalytic hydrogen evolution beyond metals. Here we couple graphitic-carbon nitride with nitrogen-doped graphene to produce a metal-free hybrid catalyst, which shows an unexpected hydrogen evolution reaction activity with comparable overpotential and Tafel slope to some of well-developed metallic catalysts. Experimental observations in combination with density functional theory calculations reveal that its unusual electrocatalytic properties originate from an intrinsic chemical and electronic coupling that synergistically promotes the proton adsorption and reduction kinetics. © 2014 Macmillan Publishers Limited. All rights reserved.

  7. Liquid uranium contaimment in refractories metals

    International Nuclear Information System (INIS)

    Duarte, J.L.; Padilha, A.F.

    1982-01-01

    Tests were performed on metalic materials for liquid uranium containment up to 2100 0 C. The materials Nb, Mo, Ta and W in the form of crucibles were tested at 2100 0 C for one hour in the presence of flowing argon. After testing, the crucibles were etched using HCl and analysed by optical metallography and electron proble microanalysis. The results are discussed in terms of Berthoud equation and indicated that the solubility limit of the crucible material in uranium at the temperature controlls the crucible dissolution by liquid uranium. The various phases formed, the mechanism of dissolution and the possible material for future use are presented and discussed. (Author) [pt

  8. Liquid metal pump for nuclear reactors

    International Nuclear Information System (INIS)

    Allen, H.G.; Maloney, J.R.

    1975-01-01

    A pump for use in pumping high temperature liquids at high pressures, particularly liquid metals used to cool nuclear reactors is described. It is of the type in which the rotor is submerged in a sump but is fed by an inlet duct which bypasses the sump. A chamber, kept full of fluid, surrounds the pump casing into which fluid is bled from the pump discharge and from which fluid is fed to the rotor bearings and hence to the sump. This equalizes pressure inside and outside the pump casing and reduces or eliminates the thermal shock to the bearings and sump tank

  9. Hydrogen as a New Alloying Element in Metals

    International Nuclear Information System (INIS)

    Shapovalov, Vladimir

    1999-01-01

    Hydrogen was regarded as a harmful impurity in many alloys and particularly in steels where it gives rise to a specific type of embrittlement and forms various discontinuities like flakes and blowholes. For this reason, the researcher efforts were mainly focused on eliminating hydrogen's negative impacts and explaining its uncommonly high diffusivity in condensed phases. Meanwhile, positive characteristics of hydrogen as an alloying element remained unknown for quite a long time. Initial reports in this field did not appear before the early 1970s. Data on new phase diagrams are given for metal-hydrogen systems where the metal may or may not form hydrides. Various kinds of hydrogen impact on structure formation in solidification, melting and solid-solid transformations are covered. Special attention is given to the most popular alloys based on iron, aluminum, copper, nickel, magnesium and titanium. Detailed is what is called gas-eutectic reaction resulting in a special type of gas-solid structure named gasarite. Properties and applications of gasars - gasaritic porous materials - are dealt with. Various versions of solid-state alloying with hydrogen are discussed that change physical properties and fabrication characteristics of metals. Details are given on a unique phenomenon of anomalous spontaneous deformation due to combination of hydrogen environment and polymorphic transformation. All currently known versions of alloying with hydrogen are categorized for both hydride-forming and non-hydrid forming metals

  10. Metal-deactivating additives for liquid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Boneva, M.I. [Institute of Organic Chemistry, Sofia (Bulgaria); Ivanov, S.K.; Kalitchin, Z.D. [SciBulCom, Ltd., Sofia (Bulgaria); Tanielyan, S.K. [Seton Hall Univ., South Orange, NJ (United States); Terebenina, A.; Todorova, O.I. [Institute of Inorganic Chemistry, Sofia (Bulgaria)

    1995-05-01

    The metal-deactivating and the antioxidant properties of 1-phenyl-3-methylpyrazolone-5 derivatives have been investigated both in the model reaction of low temperature oxidation of ethylbenzene and in gasoline oxidation. The study of the ability of these derivatives to reduce the catalytic effect of copper naphthenate demonstrates that they are promising as metal deactivating additives for light fuels. Some of the pyrazolone compounds appear to be of special interest for the long-term storage of liquid fuels due to their action as multifunctional inhibitors.

  11. Liquid metal cooled nuclear reactor constructions

    International Nuclear Information System (INIS)

    Aspden, G.J.; Allbeson, K.F.

    1984-01-01

    In a liquid metal cooled nuclear reactor with a nuclear fuel assembly in a coolant-containing primary vessel housed within a concrete containment vault, there is thermal insulation to protect the concrete, the insulation being disposed between vessel and concrete and being hung from metal structure secured to and projecting from the concrete, the insulation consisting of a plurality of adjoining units each unit incorporating a pack of thermal insulating material and defining a contained void co-extensive with said pack and situated between pack and concrete, the void of each unit being connected to the voids of adjoining units so as to form continuous ducting for a fluid coolant. (author)

  12. Sorption of radiostrontium from liquid metallic rubidium

    International Nuclear Information System (INIS)

    Zhujkov, B.L.; Kokhnyuk, V.M.; Vincent, J.S.

    2008-01-01

    One studied the radiostrontium (in particular, 82 Sr) sorption from the liquid metallic Rb in various inorganic sorbents (both metals and oxides). One studied the temperature dependence and the dynamics of the adsorption and put forward an interpretation of the observed mechanisms. The elaborated approach enables to extract 82 Sr efficiently from the Rb targets upon their irradiation by the accelerated protons. One studies various procedures and the applicability of the process to ensure elaboration of a new highly efficient process to produce 82 Sr, in particular, with the targets of the circulating Rb [ru

  13. Mechanical pumps for liquid metals; Pompes mecaniques pour metaux liquides

    Energy Technology Data Exchange (ETDEWEB)

    Baumier, J; Gollion, H J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-07-01

    The pumping of liquid metals by centrifugal pumps poses two principal problems. These are hermetic sealing of the rotating shaft and, its guidance where immersed in liquid metal. The solutions to the problems used on 13 experimental pumps are given here. The resolution of the guidance problem consists in the majority of cases in the utilisation of hydrostatic bearings. Accordingly, a theoretical study was instituted for the first time to calculate the bearings of the earlier pumps. After this, an experimental study was carried out, to check the theory by water tests. A relation for bearing calculation of pumps with diffusers is proposed. Finally the influence of the bearing elasticity on the shafts critical speed is studied. (authors) [French] Le pompage des metaux liquides, par des pompes centrifuges, pose 2 principaux problemes, qui sont: d'une part, la realisation d'une excellente etancheite au passage de l'arbre, d'autre part, son guidage sur la partie immergee dans le metal liquide. Les solutions retenues pour resoudre ces problemes sur 13 pompes experimentees sont presentees. Le probleme du guidage de l'arbre, a dans la majorite des cas ete resolu en utilisant un palier hydrostatique, aussi l'etude en a d'abord ete approfondie de facon theorique pour calculer les paliers des premieres pompes, puis experimentale pour controler la theorie, en effectuant des essais a l'eau. On propose une relation pour calculer les paliers des pompes a diffuseurs. On a en outre effectue une etude de l'influence de l'elasticite du palier hydrostatique sur la vitesse critique de l'arbre. (auteurs)

  14. A low cost liquid metal reactor design

    International Nuclear Information System (INIS)

    Arnold, W.H.; Anderson, C.A.; Mangus, J.D.

    1984-01-01

    A new, compact Liquid Metal Reactor (LMR) plant arrangement designed by Westinghouse, featuring factory-fabricated modules and an integrated fuel cycle facility, has made it possible to project a commercially competitive LMR plant for the near future. This innovative liquid metal-cooled plant design will allow a combination of capital, fuel, operation and maintenance costs that could be lower than today's fossil-fueled or light water reactor plant costs, and incorporate features which enhance public safety even beyond current high standards. Following early core loadings, the plant feeds only on depleted uranium. No shipment of fuel is required. And the plant can be tailored to produce enough plutonium to meet its need or to provide fuel for other nuclear plants

  15. Development of Korea advanced liquid metal reactor

    International Nuclear Information System (INIS)

    Park, C.K.

    1998-01-01

    Future nuclear power plants should not only have the features of improved safety and economic competitiveness but also provide a means to resolve spent fuel storage problems by minimizing volume of high level wastes. It is widely believed that liquid metal reactors (LMRs) have the highest potential of meeting these requirements. In this context, the LMR development program was launched as a national long-term R and D program in 1992, with a target to introduce a commercial LMR around 2030. Korea Advanced Liquid Metal Reactor (KALIMER), a 150 MWe pool-type sodium cooled prototype reactor, is currently under the conceptual design study with the target schedule to complete its construction by the mid-2010s. This paper summarizes the KALIMER development program and major technical features of the reactor system. (author)

  16. Liquid metal cooled fast breeder nuclear reactors

    International Nuclear Information System (INIS)

    Gatley, J.A.

    1979-01-01

    Breeder fuel sub-assemblies with electromagnetic brakes and fluidic valves for liquid metal cooled fast breeder reactors are described. The electromagnetic brakes are of relatively small proportions and the valves are of the controlled vortex type. The outlet coolant temperature of at least some of the breeder sub-assemblies are maintained by these means substantially constant throughout the life of the fuel assembly without severely pressurising the sub-assembly. (UK)

  17. Liquid metal cooled fast breeder nuclear reactors

    International Nuclear Information System (INIS)

    Thatcher, G.; Mitchell, A.J.

    1981-01-01

    Fuel sub-assemblies for liquid metal-cooled fast breeder reactors are described which each incorporate a fluid flow control valve for regulating the rate of flow through the sub-assembly. These small electro-magnetic valves seek to maintain the outlet coolant temperature of at least some of the breeder sub-assemblies substantially constant throughout the life of the fuel assembly without severely pressurising the sub-assembly. (U.K.)

  18. Advanced liquid metal reactor plant control system

    International Nuclear Information System (INIS)

    Dayal, Y.; Wagner, W.; Zizzo, D.; Carroll, D.

    1993-01-01

    The modular Advanced Liquid Metal Reactor (ALMR) power plant is controlled by an advanced state-of-the-art control system designed to facilitate plant operation, optimize availability, and protect plant investment. The control system features a high degree of automatic control and extensive amount of on-line diagnostics and operator aids. It can be built with today's control technology, and has the flexibility of adding new features that benefit plant operation and reduce O ampersand M costs as the technology matures

  19. Pool type liquid metal fast breeder reactors

    International Nuclear Information System (INIS)

    Guthrie, B.M.

    1978-08-01

    Various technical aspects of the liquid metal fast breeder reactor (LMFBR), specifically pool type LMFBR's, are summarized. The information presented, for the most part, draws upon existing data. Special sections are devoted to design, technical feasibility (normal operating conditions), and safety (accident conditions). A survey of world fast reactors is presented in tabular form, as are two sets of reference reactor parameters based on available data from present and conceptual LMFBR's. (auth)

  20. Hydrogen adsorption in metal-decorated silicon carbide nanotubes

    Science.gov (United States)

    Singh, Ram Sevak; Solanki, Ankit

    2016-09-01

    Hydrogen storage for fuel cell is an active area of research and appropriate materials with excellent hydrogen adsorption properties are highly demanded. Nanotubes, having high surface to volume ratio, are promising storage materials for hydrogen. Recently, silicon carbide nanotubes have been predicted as potential materials for future hydrogen storage application, and studies in this area are ongoing. Here, we report a systematic study on hydrogen adsorption properties in metal (Pt, Ni and Al) decorated silicon carbide nanotubes (SiCNTs) using first principles calculations based on density functional theory. The hydrogen adsorption properties are investigated by calculations of adsorption energy, electronic band structure, density of states (DOS) and Mulliken charge population analysis. Our findings show that hydrogen adsorptions on Pt, Ni and Al-decorated SiCNTs undergo spontaneous exothermic reactions with significant modulation of electronic structure of SiCNTs in all cases. Importantly, according to the Mulliken charge population analysis, dipole-dipole interaction causes chemisorptions of hydrogen in Pt, Ni and Al decorated SiCNTs with formation of chemical bonds. The study is a platform for the development of metal decorated SiCNTs for hydrogen adsorption or hydrogen storage application.

  1. Hydrogen isotope separation in hydrophobic catalysts between hydrogen and liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Linsen, E-mail: yls2005@mail.ustc.edu.cn [China Academy of Engineering Physics, Mianyang 621900 (China); Luo, Deli [Science and Technology on Surface Physics and Chemistry Laboratory, Jiangyou 621907 (China); Tang, Tao; Yang, Wan; Yang, Yong [China Academy of Engineering Physics, Mianyang 621900 (China)

    2015-11-15

    Hydrogen isotope catalytic exchange between hydrogen and liquid water is a very effective process for deuterium-depleted potable water production and heavy water detritiation. To improve the characteristics of hydrophobic catalysts for this type of reaction, foamed and cellular structures of hydrophobic carbon-supported platinum catalysts were successfully prepared. Separation of deuterium or tritium from liquid water was carried out by liquid-phase catalytic exchange. At a gas–liquid ratio of 1.53 and exchange temperature of 70 °C, the theoretical plate height of the hydrophobic catalyst (HETP = 34.2 cm) was slightly lower than previously reported values. Changing the concentration of the exchange column outlet water yielded nonlinear changes in the height of the packing layer. Configurations of deuterium-depleted potable water and detritiation of heavy water provide references for practical applications.

  2. Solutions to commercializing metal hydride hydrogen storage products

    International Nuclear Information System (INIS)

    Tomlinson, J.J.; Belanger, R.

    2004-01-01

    'Full text:' Whilst the concept of a Hydrogen economy in the broad sense may for some analysts and Fuel Cell technology developers be an ever moving target the use of hydrogen exists and is growing in other markets today. The use of hydrogen is increasing. Who are the users? What are their unique needs? How can they better be served? As the use of hydrogen increases there are things we can do to improve the perception and handling of hydrogen as an industrial gas that will impact the future issues of hydrogen as a fuel thereby assisting the mainstream availability of hydrogen fuel a reality. Factors that will induce change in the way hydrogen is used, handled, transported and stored are the factors to concentrate development efforts on. Other factors include: cost; availability; safety; codes and standards; and regulatory authorities acceptance of new codes and standards. New methods of storage and new devices in which the hydrogen is stored will influence and bring about change and increased use. New innovative products based on Metal Hydride hydrogen storage will address some of the barriers to widely distributed hydrogen as a fuel or energy carrier to which successful fuel cell product commercialization is subject. Palcan has developed innovative products based on it's Rare Earth Metal Hydride alloy. Some of these innovations will aid the distribution of hydrogen as a fuel and offer alternatives to the existing hydrogen user and to the Fuel Cell product developer. An overview of the products and how these products will affect the distribution and use of hydrogen as an industrial gas and fuel is presented. (author)

  3. Interactions of hydrogen isotopes and oxides with metal tubes

    International Nuclear Information System (INIS)

    Longhurst, G. R.; Cleaver, J.

    2008-01-01

    Understanding and accounting for interaction of hydrogen isotopes and their oxides with metal surfaces is important for persons working with tritium systems. Reported data from several investigators have shown that the processes of oxidation, adsorption, absorption, and permeation are all coupled and interactive. A computer model has been developed for predicting the interaction of hydrogen isotopes and their corresponding oxides in a flowing carrier gas stream with the walls of a metallic tube, particularly at low hydrogen concentrations. An experiment has been constructed to validate the predictive model. Predictions from modeling lead to unexpected experiment results. (authors)

  4. Interactions of hydrogen isotopes and oxides with metal tubes

    Energy Technology Data Exchange (ETDEWEB)

    Longhurst, G. R. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-3860 (United States); Cleaver, J. [Idaho State Univ., 921 South 8th Avenue, Pocatello, ID 83201 (United States)

    2008-07-15

    Understanding and accounting for interaction of hydrogen isotopes and their oxides with metal surfaces is important for persons working with tritium systems. Reported data from several investigators have shown that the processes of oxidation, adsorption, absorption, and permeation are all coupled and interactive. A computer model has been developed for predicting the interaction of hydrogen isotopes and their corresponding oxides in a flowing carrier gas stream with the walls of a metallic tube, particularly at low hydrogen concentrations. An experiment has been constructed to validate the predictive model. Predictions from modeling lead to unexpected experiment results. (authors)

  5. Interactions of Hydrogen Isotopes and Oxides with Metal Tubes

    International Nuclear Information System (INIS)

    Longhurst, Glen R.

    2008-01-01

    Understanding and accounting for interaction of hydrogen isotopes and their oxides with metal surfaces is important for persons working with tritium systems. Reported data from several investigators have shown that the processes of oxidation, adsorption, absorption, and permeation are all coupled and interactive. A computer model has been developed for predicting the interaction of hydrogen isotopes and their corresponding oxides in a flowing carrier gas stream with the walls of a metallic tube, particularly at low hydrogen concentrations. An experiment has been constructed to validate the predictive model. Predictions from modeling lead to unexpected experiment results

  6. Method and apparatus for electrokinetic co-generation of hydrogen and electric power from liquid water microjets

    Energy Technology Data Exchange (ETDEWEB)

    Saykally, Richard J; Duffin, Andrew M; Wilson, Kevin R; Rude, Bruce S

    2013-02-12

    A method and apparatus for producing both a gas and electrical power from a flowing liquid, the method comprising: a) providing a source liquid containing ions that when neutralized form a gas; b) providing a velocity to the source liquid relative to a solid material to form a charged liquid microjet, which subsequently breaks up into a droplet spay, the solid material forming a liquid-solid interface; and c) supplying electrons to the charged liquid by contacting a spray stream of the charged liquid with an electron source. In one embodiment, where the liquid is water, hydrogen gas is formed and a streaming current is generated. The apparatus comprises a source of pressurized liquid, a microjet nozzle, a conduit for delivering said liquid to said microjet nozzle, and a conductive metal target sufficiently spaced from said nozzle such that the jet stream produced by said microjet is discontinuous at said target. In one arrangement, with the metal nozzle and target electrically connected to ground, both hydrogen gas and a streaming current are generated at the target as it is impinged by the streaming, liquid spray microjet.

  7. Current Design of the Flange Type Hydrogen Permeation Sensor in Liquid Breeder

    International Nuclear Information System (INIS)

    Lee, E. H.; Jin, H. G.; Yoon, J. S.; Kim, S. K.; Lee, D. W.; Lee, H. G.

    2015-01-01

    In 2004, A. Ciampichetti et al. proposed a hollow capsule shape permeation sensor and they theoretically and experimentally evaluated the performance of the sensor made of Nb membrane at test condition of 500 .deg. C. However, the evaluation result showed the measured hydrogen permeation flux in the sensor much lower than the predicted one and they concluded that, the result is due to the formation of an oxide layer on the sensor membrane surface. Three years later, A. Ciampichetti et al. observed that a hollow capsule shape permeation sensor has too long response time to measure hydrogen concentration in liquid breeder. However, they suggested optimizing the sensor geometry with the reduction of the ratio 'total sensor volume/permeation surface' to overcome the low hydrogen permeating flux. For development of the liquid breeding technologies in nuclear fusion, the permeation sensor to measure tritium concentration in liquid metal breeder has been developed. Lee et al. proposed a flange type permeation sensor to dramatically reduce the ratio sensor 'inside volume/permeation surface' and to remove membrane welding during sensor manufacture process. However, the flange type sensor has problem with sealing. In present study, the modified flange sensor design with a metallic C-ring spring gasket is introduced. The modified sensor will be verified and evaluated under high temperature conditions by end of 2015

  8. Current Design of the Flange Type Hydrogen Permeation Sensor in Liquid Breeder

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E. H.; Jin, H. G.; Yoon, J. S.; Kim, S. K.; Lee, D. W. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, H. G. [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    In 2004, A. Ciampichetti et al. proposed a hollow capsule shape permeation sensor and they theoretically and experimentally evaluated the performance of the sensor made of Nb membrane at test condition of 500 .deg. C. However, the evaluation result showed the measured hydrogen permeation flux in the sensor much lower than the predicted one and they concluded that, the result is due to the formation of an oxide layer on the sensor membrane surface. Three years later, A. Ciampichetti et al. observed that a hollow capsule shape permeation sensor has too long response time to measure hydrogen concentration in liquid breeder. However, they suggested optimizing the sensor geometry with the reduction of the ratio 'total sensor volume/permeation surface' to overcome the low hydrogen permeating flux. For development of the liquid breeding technologies in nuclear fusion, the permeation sensor to measure tritium concentration in liquid metal breeder has been developed. Lee et al. proposed a flange type permeation sensor to dramatically reduce the ratio sensor 'inside volume/permeation surface' and to remove membrane welding during sensor manufacture process. However, the flange type sensor has problem with sealing. In present study, the modified flange sensor design with a metallic C-ring spring gasket is introduced. The modified sensor will be verified and evaluated under high temperature conditions by end of 2015.

  9. Process for exchanging hydrogen isotopes between gaseous hydrogen and water

    International Nuclear Information System (INIS)

    Hindin, S. G.; Roberts, G. W.

    1980-01-01

    A process for exchanging isotopes of hydrogen, particularly tritium, between gaseous hydrogen and water is provided whereby gaseous hydrogen depeleted in tritium and liquid or gaseous water containing tritium are reacted in the presence of a metallic catalyst

  10. The US Liquid Metal Reactor Development Program

    International Nuclear Information System (INIS)

    Till, C.E.; Arnold, W.H.; Griffith, J.D.

    1988-01-01

    The US Liquid Metal Reactor Development Program has been restructured to take advantage of the opportunity today to carry out R and D on truly advanced reactor technology. The program gives particular emphasis to improvements to reactor safety. The new directions are based on the technology of the Integral Fast Reactor (IFR). Much of the basis for superior safety performance using IFR technology has been experimentally verified and aggressive programs continue in EBR-II and TREAT. Progress has been made in demonstrating both the metallic fuel and the new electrochemical processes of the IFR. The FFTF facility is converting to metallic fuel; however, FFTF also maintains a considerable US program in oxide fuels. In addition, generic programs are continuing in steam generator testing, materials development, and, with international cooperation, aqueous reprocessing. Design studies are carried out in conjunction with the IFR technology development program. In summary, the US maintains an active development program in Liquid Metal Reactor technology, and new directions in reactor safety are central to the program

  11. Integrated Refrigeration and Storage for Advanced Liquid Hydrogen Operations

    Science.gov (United States)

    Swanger, A. M.; Notardonato, W. U.; Johnson, W. L.; Tomsik, T. M.

    2016-01-01

    NASA has used liquefied hydrogen (LH2) on a large scale since the beginning of the space program as fuel for the Centaur and Apollo upper stages, and more recently to feed the three space shuttle main engines. The LH2 systems currently in place at the Kennedy Space Center (KSC) launch pads are aging and inefficient compared to the state-of-the-art. Therefore, the need exists to explore advanced technologies and operations that can drive commodity costs down, and provide increased capabilities. The Ground Operations Demonstration Unit for Liquid Hydrogen (GODU-LH2) was developed at KSC to pursue these goals by demonstrating active thermal control of the propellant state by direct removal of heat using a cryocooler. The project has multiple objectives including zero loss storage and transfer, liquefaction of gaseous hydrogen, and densification of liquid hydrogen. The key technology challenge was efficiently integrating the cryogenic refrigerator into the LH2 storage tank. A Linde LR1620 Brayton cycle refrigerator is used to produce up to 900W cooling at 20K, circulating approximately 22 g/s gaseous helium through the hydrogen via approximately 300 m of heat exchanger tubing. The GODU-LH2 system is fully operational, and is currently under test. This paper will discuss the design features of the refrigerator and storage system, as well as the current test results.

  12. New Transition metal assisted complex borohydrides for hydrogen storage

    International Nuclear Information System (INIS)

    Sesha Srinivasan; Elias Lee Stefanakos; Yogi Goswami

    2006-01-01

    High capacity hydrogen storage systems are indeed essential for the on-board vehicular application that leads to the pollution free environment. Apart from the various hydrogen storage systems explored in the past, complex hydrides involving light weight alkali/alkaline metals exhibits promising hydrogenation/ dehydrogenation characteristics. New transition metal assisted complex borohydrides [Zn(BH 4 ) 2 ] have been successfully synthesized by an inexpensive mechano-chemical process. These complex hydrides possesses gravimetric hydrogen storage capacity of ∼8.4 wt.% at around 120 C. We have determined the volumetric hydrogen absorption and desorption of these materials for a number of cycles. Another complex borohydride mixture LiBH 4 /MgH 2 catalyzed with ZnCl 2 has been synthesized and characterized using various analytical techniques. (authors)

  13. Additive Manufacturing a Liquid Hydrogen Rocket Engine

    Science.gov (United States)

    Jones, Carl P.; Robertson, Elizabeth H.; Koelbl, Mary Beth; Singer, Chris

    2016-01-01

    Space Propulsion is a 5 day event being held from 2nd May to the 6th May 2016 at the Rome Marriott Park Hotel in Rome, Italy. This event showcases products like Propulsion sub-systems and components, Production and manufacturing issues, Liquid, Solid, Hybrid and Air-breathing Propulsion Systems for Launcher and Upper Stages, Overview of current programmes, AIV issues and tools, Flight testing and experience, Technology building blocks for Future Space Transportation Propulsion Systems : Launchers, Exploration platforms & Space Tourism, Green Propulsion for Space Transportation, New propellants, Rocket propulsion & global environment, Cost related aspects of Space Transportation propulsion, Modelling, Pressure-Thrust oscillations issues, Impact of new requirements and regulations on design etc. in the Automotive, Manufacturing, Fabrication, Repair & Maintenance industries.

  14. Warm Pressurant Gas Effects on the Liquid Hydrogen Bubble Point

    Science.gov (United States)

    Hartwig, Jason W.; McQuillen, John B.; Chato, David J.

    2013-01-01

    This paper presents experimental results for the liquid hydrogen bubble point tests using warm pressurant gases conducted at the Cryogenic Components Cell 7 facility at the NASA Glenn Research Center in Cleveland, Ohio. The purpose of the test series was to determine the effect of elevating the temperature of the pressurant gas on the performance of a liquid acquisition device. Three fine mesh screen samples (325 x 2300, 450 x 2750, 510 x 3600) were tested in liquid hydrogen using cold and warm noncondensible (gaseous helium) and condensable (gaseous hydrogen) pressurization schemes. Gases were conditioned from 0 to 90 K above the liquid temperature. Results clearly indicate a degradation in bubble point pressure using warm gas, with a greater reduction in performance using condensable over noncondensible pressurization. Degradation in the bubble point pressure is inversely proportional to screen porosity, as the coarsest mesh demonstrated the highest degradation. Results here have implication on both pressurization and LAD system design for all future cryogenic propulsion systems. A detailed review of historical heated gas tests is also presented for comparison to current results.

  15. Hydrogen storage in metal-organic frameworks: A review

    CSIR Research Space (South Africa)

    Langmi, Henrietta W

    2014-05-01

    Full Text Available Metal-organic frameworks (MOFs) for hydrogen storage have continued to receive intense interest over the past decade. MOFs are a class of organic-inorganic hybrid crystalline materials consisting of metallic moieties that are linked by strong...

  16. Precipitation of metal sulphides using gaseous hydrogen sulphide: mathematical modelling

    NARCIS (Netherlands)

    Al Tarazi, M.Y.M.; Heesink, Albertus B.M.; Versteeg, Geert

    2004-01-01

    A mathematical model has been developed that describes the precipitation of metal sulffides in an aqueous solution containing two different heavy metal ions. The solution is assumed to consist of a well-mixed bulk and a boundary layer that is contacted with hydrogen sulphide gas. The model makes use

  17. Precipitation of metal sulphides using gaseous hydrogen sulphide : mathematical modelling

    NARCIS (Netherlands)

    Tarazi, Mousa Al-; Heesink, A. Bert M.; Versteeg, Geert F.

    2004-01-01

    A mathematical model has been developed that describes the precipitation of metal sulphides in an aqueous solution containing two different heavy metal ions. The solution is assumed to consist of a well-mixed bulk and a boundary layer that is contacted with hydrogen sulphide gas. The model makes use

  18. Gas--liquid equilibria in mixtures of hydrogen and thianaphthene

    Energy Technology Data Exchange (ETDEWEB)

    Sebastian, H M; Simnick, J J; Lin, H M; Chao, K C

    1978-12-01

    Gas--liquid equilibrium conditions in binary mixtures of hydrogen and thianaphthene were experimentally determined at temperature of 190 to 430/sup 0/C and pressures to 250 atm in a flow apparatus. The same apparatus was also employed to measure the vapor pressure of thianaphthene. Comparisons of the new mixture data with Chao--Seader and Grayson--Streed correlations show that both correlations predict the thianaphthene equilibrium ratios well but are in error by up to about 45 and 35% respectively for K-values of hydrogen. 4 figures, 2 tables.

  19. Hydrogen embrittlement and stress corrosion cracking in metals

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Suk; Cheong, Yong Mu; Im, Kyung Soo

    2004-10-15

    The objective of this report is to elucidate the mechanism for hydrogen embrittlement (HE) and stress corrosion cracking (SCC) in metals. To this end, we investigate the common features between delayed hydride cracking (DHC) in zirconium alloys and HE in metals with no precipitation of hydrides including Fe base alloys, Nickel base alloys, Cu alloys and Al alloys. Surprisingly, as with the crack growth pattern for the DHC in zirconium alloy, the metals mentioned above show a discontinuous crack growth, striation lines and a strong dependence of yield strength when exposed to hydrogen internally and externally. This study, for the first time, analyzes the driving force for the HE in metals in viewpoints of Kim's DHC model that a driving force for the DHC in zirconium alloys is a supersaturated hydrogen concentration coming from a hysteresis of the terminal solid solubility of hydrogen, not by the stress gradient, As with the crack growing only along the hydride habit plane during the DHC in zirconium alloys, the metals exposed to hydrogen seem to have the crack growing by invoking the dislocation slip along the preferential planes as a result of some interactions of the dislocations with hydrogen. Therefore, it seems that the hydrogen plays a role in inducing the slip only on the preferential planes so as to cause a strain localization at the crack tip. Sulfur in metals is detrimental in causing a intergranular cracking due to a segregation of the hydrogens at the grain boundaries. In contrast, boron in excess of 500 ppm added to the Ni3Al intermetallic compound is found to be beneficial in suppressing the HE even though further details of the mechanism for the roles of boron and sulfur are required. Carbon, carbides precipitating semi-continuously along the grain boundaries and the CSL (coherent site lattice) boundaries is found to suppress the intergranular stress corrosion cracking (IGSCC) in Alloy 600. The higher the volume fraction of twin boundaries, the

  20. Hydrogen embrittlement and stress corrosion cracking in metals

    International Nuclear Information System (INIS)

    Kim, Young Suk; Cheong, Yong Mu; Im, Kyung Soo

    2004-10-01

    The objective of this report is to elucidate the mechanism for hydrogen embrittlement (HE) and stress corrosion cracking (SCC) in metals. To this end, we investigate the common features between delayed hydride cracking (DHC) in zirconium alloys and HE in metals with no precipitation of hydrides including Fe base alloys, Nickel base alloys, Cu alloys and Al alloys. Surprisingly, as with the crack growth pattern for the DHC in zirconium alloy, the metals mentioned above show a discontinuous crack growth, striation lines and a strong dependence of yield strength when exposed to hydrogen internally and externally. This study, for the first time, analyzes the driving force for the HE in metals in viewpoints of Kim's DHC model that a driving force for the DHC in zirconium alloys is a supersaturated hydrogen concentration coming from a hysteresis of the terminal solid solubility of hydrogen, not by the stress gradient, As with the crack growing only along the hydride habit plane during the DHC in zirconium alloys, the metals exposed to hydrogen seem to have the crack growing by invoking the dislocation slip along the preferential planes as a result of some interactions of the dislocations with hydrogen. Therefore, it seems that the hydrogen plays a role in inducing the slip only on the preferential planes so as to cause a strain localization at the crack tip. Sulfur in metals is detrimental in causing a intergranular cracking due to a segregation of the hydrogens at the grain boundaries. In contrast, boron in excess of 500 ppm added to the Ni3Al intermetallic compound is found to be beneficial in suppressing the HE even though further details of the mechanism for the roles of boron and sulfur are required. Carbon, carbides precipitating semi-continuously along the grain boundaries and the CSL (coherent site lattice) boundaries is found to suppress the intergranular stress corrosion cracking (IGSCC) in Alloy 600. The higher the volume fraction of twin boundaries, the more

  1. Reaction rates and electrical resistivities of the hydrogen isotopes with, and their solubilities in, liquid lithium

    International Nuclear Information System (INIS)

    Pulham, R.J.; Adams, P.F.; Hubberstey, P.; Parry, G.; Thunder, A.E.

    1976-01-01

    The rate of reaction, k, of hydrogen and of deuterium with liquid lithium have been determined up to pressures of 20kNm -2 and at temperatures between 230 and 270 0 C. The reaction is first order with an apparent activation energy of 52.8 and 55.2 kJmol -1 for hydrogen and deuterium, respectively. The deuterium isotope effect, k/sub H/k/sub D/, decreases from 2.95 at 230 to 2.83 at 270 0 C. Tritium is predicted to react even more slowly than deuterium. The freezing point of lithium is depressed by 0.082 and 0.075 0 C, respectively, by dissolved hydride and deuteride giving eutectics at 0.016 mol percent H and 0.012 mol percent D in the metal-salt phase diagrams. The depression and eutectic concentration are expected to be less for tritium. The increase in the resistivity of liquid lithium caused by dissolved hydrogen isotopes is linear and relatively large, 5 x 10 -8 Ωm (mol percent H or D) -1 . The solubility of lithium hydride and deuteride was determined from the marked change in resistivity on saturation. The liquidus of the metal-salt phase diagram rises steeply from the eutectic point to meet the two-immiscible liquid region. Tritium is expected to be less soluble than deuterium. The partial molar enthalpies of solution are 44.2 and 55.0 kJmol -1 for hydrogen and deuterium, respectively. These values are used to calculate the solvation enthalpies of the isotope anions in the metal

  2. Complex metal hydrides for hydrogen, thermal and electrochemical energy storage

    DEFF Research Database (Denmark)

    Møller, Kasper T.; Sheppard, Drew; Ravnsbæk, Dorthe B.

    2017-01-01

    field. This review illustrates that complex metal hydrides may store hydrogen in the solid state, act as novel battery materials, both as electrolytes and electrode materials, or store solar heat in a more efficient manner as compared to traditional heat storage materials. Furthermore, it is highlighted...... how complex metal hydrides may act in an integrated setup with a fuel cell. This review focuses on the unique properties of light element complex metal hydrides mainly based on boron, nitrogen and aluminum, e.g., metal borohydrides and metal alanates. Our hope is that this review can provide new...

  3. Hydrogen damage in metals, particularly in steels

    International Nuclear Information System (INIS)

    Funes, A.J.

    1982-03-01

    Hydrogen damage examples of practical interest for the engineer are presented, showing the scope of the problem and its importance in relation to technological development, particularly of CANDU reactor and of heavy water production plants. The fundamental triangle of the hydrogen embrittlement is established as follows: presence of hydrogen in the crystalline network, structure susceptible of damage, and effort. The initial collection of examples is classified in function of the observed effects. For the consideration of the causes of said effects three models of hydrogen interaction with the crystalline network are described, indicating their scopes and limitations. Then the use of the models is explained, both in order to obtain practical information (evaluation tests, acceptance and rejection criteria) and for the validation and improvement of the models themselves (study methods). Solutions for attenuating the hydrogen embrittlement and a programme of studies and tests are proposed to be carried out by the National Atomic Energy Commission. Among the latter, the local development of a microimpression method to detect the evaluation of absorbed hydrogen, comparable with the autoradiography of high resolution, and a mechanical test yielding results on fragility comparable with those obtained through the test of standard disks, are described. (M.E.L.) [es

  4. Oscillatory Convection in Rotating Liquid Metals

    Science.gov (United States)

    Bertin, Vincent; Grannan, Alex; Aurnou, Jonathan

    2016-11-01

    We have performed laboratory experiments in a aspect ratio Γ = 2 cylinder using liquid gallium (Pr = 0 . 023) as the working fluid. The Ekman number varies from E = 4 ×10-5 to 4 ×10-6 and the Rayleigh number varies from Ra = 3 ×105 to 2 ×107 . Using heat transfer and temperature measurements within the fluid, we characterize the different styles of low Pr rotating convective flow. The convection threshold is first overcome in the form of a container scale inertial oscillatory mode. At stronger forcing, wall-localized modes develop, coexisting with the inertial oscillatory modes in the bulk. When the strength of the buoyancy increases further, the bulk flow becomes turbulent while the wall modes remain. Our results imply that rotating convective flows in liquid metals do not develop in the form of quasi-steady columns, as in Pr = 1 planetary and stellar dynamo models, but in the form of oscillatory motions. Therefore, convection driven dynamo action in low Pr fluids can differ substantively than that occurring in typical Pr = 1 numerical models. Our results also suggest that low wavenumber, wall modes may be dynamically and observationally important in liquid metal dynamo systems. We thank the NSF Geophysics Program for support of this project.

  5. Deuterium isotope separation factor between hydrogen and liquid water

    International Nuclear Information System (INIS)

    Rolston, J.H.; den Hartog, J.; Butler, J.P.

    1976-01-01

    The overall deuterium isotope separation factor between hydrogen and liquid water, α, has been measured directly for the first time between 280 and 370 0 K. The data are in good agreement with values of α calculated from literature data on the equilibrium constant for isotopic exchange between hydrogen and water vapor, K 1 , and the liquid-vapor separation factor, α/sub V/. The temperature dependence of α over the range 273-473 0 K based upon these new experimental results and existing literature data is given by the equation ln α = -0.2143 + (368.9/T) + (27,870/T 2 ). Measurements on α/sub V/ given in the literature have been surveyed and the results are summarized over the same temperature range by the equation ln α/sub V/ = 0.0592 - (80.3/T) +

  6. Theoretical study of hydrogen storage in metal hydrides.

    Science.gov (United States)

    Oliveira, Alyson C M; Pavão, A C

    2018-05-04

    Adsorption, absorption and desorption energies and other properties of hydrogen storage in palladium and in the metal hydrides AlH 3 , MgH 2 , Mg(BH 4 ) 2 , Mg(BH 4 )(NH 2 ) and LiNH 2 were analyzed. The DFT calculations on cluster models show that, at a low concentration, the hydrogen atom remains adsorbed in a stable state near the palladium surface. By increasing the hydrogen concentration, the tetrahedral and the octahedral sites are sequentially occupied. In the α phase the tetrahedral site releases hydrogen more easily than at the octahedral sites, but the opposite occurs in the β phase. Among the hydrides, Mg(BH 4 ) 2 shows the highest values for both absorption and desorption energies. The absorption energy of LiNH 2 is higher than that of the palladium, but its desorption energy is too high, a recurrent problem of the materials that have been considered for hydrogen storage. The release of hydrogen, however, can be favored by using transition metals in the material structure, as demonstrated here by doping MgH 2 with 3d and 4d-transition metals to reduce the hydrogen atomic charge and the desorption energy.

  7. Liquid metal reactor core material HT9

    International Nuclear Information System (INIS)

    Kim, S. H.; Kuk, I. H.; Ryu, W. S. and others

    1998-03-01

    A state-of-the art is surveyed on the liquid metal reactor core materials HT9. The purpose of this report is to give an insight for choosing and developing the materials to be applied to the KAERI prototype liquid metal reactor which is planned for the year of 2010. In-core stability of cladding materials is important to the extension of fuel burnup. Austenitic stainless steel (AISI 316) has been used as core material in the early LMR due to the good mechanical properties at high temperatures, but it has been found to show a poor swelling resistance. So many efforts have been made to solve this problem that HT9 have been developed. HT9 is 12Cr-1MoVW steel. The microstructure of HT9 consisted of tempered martensite with dispersed carbide. HT9 has superior irradiation swelling resistance as other BCC metals, and good sodium compatibility. HT9 has also a good irradiation creep properties below 500 dg C, but irradiation creep properties are degraded above 500 dg C. Researches are currently in progress to modify the HT9 in order to improve the irradiation creep properties above 500 dg C. New design studies for decreasing the core temperature below 500 dg C are needed to use HT9 as a core material. On the contrary, decrease of the thermal efficiency may occur due to lower-down of the operation temperature. (author). 51 refs., 6 tabs., 19 figs

  8. Properties of structural materials in liquid metal environment. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Borgstedt, H U [ed.

    1991-12-15

    The International Working Group on Fast Reactors (IWGFR) Specialists Meeting on Properties of Structural Materials in Liquid Metal Environment was held during June 18 to June 20, 1991, at the Nuclear Research Centre (Kernforschungszentrum) in Karlsruhe, Germany. The Specialists Meeting was divided into five technical sessions which addressed topics as follows: Creep-Rupture Behaviour of Structural Materials in Liquid Metal Environment; Behaviour of Materials in Liquid Metal Environments under Off-Normal Conditions;Fatigue and Creep-Fatigue of Structural Materials in Liquid Metal Environment; Crack Propagation in Liquid Sodium; and Conclusions and recommendations. Individual papers have been cataloged separately.

  9. Evidence for a first-order liquid-liquid transition in high-pressure hydrogen from ab initio simulations.

    Science.gov (United States)

    Morales, Miguel A; Pierleoni, Carlo; Schwegler, Eric; Ceperley, D M

    2010-07-20

    Using quantum simulation techniques based on either density functional theory or quantum Monte Carlo, we find clear evidence of a first-order transition in liquid hydrogen, between a low conductivity molecular state and a high conductivity atomic state. Using the temperature dependence of the discontinuity in the electronic conductivity, we estimate the critical point of the transition at temperatures near 2,000 K and pressures near 120 GPa. Furthermore, we have determined the melting curve of molecular hydrogen up to pressures of 200 GPa, finding a reentrant melting line. The melting line crosses the metalization line at 700 K and 220 GPa using density functional energetics and at 550 K and 290 GPa using quantum Monte Carlo energetics.

  10. Heat transfer analysis of liquid piston compressor for hydrogen applications

    DEFF Research Database (Denmark)

    Kermani, Nasrin Arjomand; Rokni, Masoud

    2015-01-01

    A hydrogen compression technology using liquid as the compression piston is investigated from heat transfer point of view. A thermodynamic model, simulating a single compression stroke, is developed to investigate the heat transfer phenomena inside the compression chamber. The model is developed...... and through the walls, is investigated and compared with the adiabatic case. The results show that depending on heat transfer correlation, the hydrogen temperature reduces slightly between 0.2% and 0.4% compared to the adiabatic case, at 500bar, due to the large wall resistance and small contact area...... at the interface. Moreover, the results of the sensitivity analysis illustrates that increasing the total heat transfer coefficients at the interface and the wall, together with compression time, play key roles in reducing the hydrogen temperature. Increasing the total heat transfer coefficient at the interface...

  11. The coalescence of heterogeneous liquid metal on nano substrate

    Science.gov (United States)

    Wang, Long; Li, Yifan; Zhou, Xuyan; Li, Tao; Li, Hui

    2017-06-01

    Molecular dynamics simulation has been performed to study the asymmetric coalescence of heterogeneous liquid metal on graphene. Simulation results show that the anomalies in the drop coalescence is mainly caused by the wettability of heterogeneous liquid metal. The silver atoms incline to distribute on the outer layer of the gold and copper droplets, revealing that the structure is determined by the interaction between different metal atoms. The coalescence and fusion of heterogeneous liquid metal drop can be predicted by comparing the wettability and the atomic mass of metallic liquid drops, which has important implications in the industrial application such as ink-jet printing and metallurgy.

  12. Metal-functionalized silicene for efficient hydrogen storage.

    Science.gov (United States)

    Hussain, Tanveer; Chakraborty, Sudip; Ahuja, Rajeev

    2013-10-21

    First-principles calculations based on density functional theory are used to investigate the electronic structure along with the stability, bonding mechanism, band gap, and charge transfer of metal-functionalized silicene to envisage its hydrogen-storage capacity. Various metal atoms including Li, Na, K, Be, Mg, and Ca are doped into the most stable configuration of silicene. The corresponding binding energies and charge-transfer mechanisms are discussed from the perspective of hydrogen-storage compatibility. The Li and Na metal dopants are found to be ideally suitable, not only for strong metal-to-substrate binding and uniform distribution over the substrate, but also for the high-capacity storage of hydrogen. The stabilities of both Li- and Na-functionalized silicene are also confirmed through molecular dynamics simulations. It is found that both of the alkali metals, Li(+) and Na(+), can adsorb five hydrogen molecules, attaining reasonably high storage capacities of 7.75 and 6.9 wt %, respectively, with average adsorption energies within the range suitable for practical hydrogen-storage applications. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Microscopic dynamics and relaxation processes in liquid hydrogen fluoride

    International Nuclear Information System (INIS)

    Angelini, R.; Giura, P.; Monaco, G.; Sette, F.; Fioretto, D.; Ruocco, G.

    2004-01-01

    Inelastic x-ray scattering and Brillouin light scattering measurements of the dynamic structure factor of liquid hydrogen fluoride have been performed in the temperature range T=214-283 K. The data, analyzed using a viscoelastic model with a two time-scale memory function, show a positive dispersion of the sound velocity c(Q) between the low frequency value c 0 (Q) and the high frequency value c ∞α (Q). This finding confirms the existence of a structural (α) relaxation directly related to the dynamical organization of the hydrogen bonds network of the system. The activation energy E a of the process has been extracted by the analysis of the temperature behavior of the relaxation time τ α (T) that follows an Arrhenius law. The obtained value for E a , when compared with that observed in another hydrogen bond liquid as water, suggests that the main parameter governing the α-relaxation process is the number of hydrogen bonds per molecule

  14. Liquid metals as electrodes in polymer light emitting diodes

    NARCIS (Netherlands)

    Andersson, G.G.; Gommans, H.H.P.; Denier van der Gon, A.W.; Brongersma, H.H.

    2003-01-01

    We demonstrate that liquid metals can be used as cathodes in light emitting diodes (pLEDs). The main difference between the use of liquid cathodes and evaporated cathodes is the sharpness of the metal–polymer interface. Liquid metal cathodes result in significantly sharper metal–organic interfaces

  15. Metal oxide/hydrogen battery; Kinzoku sankabutsu/suiso denchi

    Energy Technology Data Exchange (ETDEWEB)

    Kanda, M.; Niki, H. [Toshiba Research and Development Centre, Komukai, Kawasaki (Japan)

    1995-07-04

    The metal oxide-hydrogen battery consisting mainly of hydrogen storage alloy has high energy density and high volume efficiency. However, it is disadvantageous that the self-discharge takes place since the discharge capacity is lowered due to the delivery of stored hydrogen from the hydrogen electrode. This invention relates to the metal oxide-hydrogen battery consisting of hydrogen storage alloy. Hydrogen storage alloy which is composed of LaNi5 system homogeneous solid solution having an equilibrium plateau pressure of less than 1 atm at 20{degree}C is used. As a result, the battery voltage change and the self-discharge can be reduced, and the cell performance can be improved. Examples of LaNi5 system hydrogen storage alloy are ANi(5-x)Mx (A = La, Mm, and Ca, M = Al, Mn, Si, Ge, Fe, B, Ga, Cu, In, and Co). LaNi(4.7)Al(0.3) and MmNi(4.2)Mn(0.8) are preferable. 3 figs.

  16. Glass Bubbles Insulation for Liquid Hydrogen Storage Tanks

    Science.gov (United States)

    Sass, J. P.; SaintCyr, W. W.; Barrett, T. M.; Baumgartner, R. G.; Lott, J. W.; Fesmire, J. E.

    2009-01-01

    A full-scale field application of glass bubbles insulation has been demonstrated in a 218,000 L liquid hydrogen storage tank. This work is the evolution of extensive materials testing, laboratory scale testing, and system studies leading to the use of glass bubbles insulation as a cost efficient and high performance alternative in cryogenic storage tanks of any size. The tank utilized is part of a rocket propulsion test complex at the NASA Stennis Space Center and is a 1960's vintage spherical double wall tank with an evacuated annulus. The original perlite that was removed from the annulus was in pristine condition and showed no signs of deterioration or compaction. Test results show a significant reduction in liquid hydrogen boiloff when compared to recent baseline data prior to removal of the perlite insulation. The data also validates the previous laboratory scale testing (1000 L) and full-scale numerical modeling (3,200,000 L) of boiloff in spherical cryogenic storage tanks. The performance of the tank will continue to be monitored during operation of the tank over the coming years. KEYWORDS: Glass bubble, perlite, insulation, liquid hydrogen, storage tank.

  17. Equilibrium of current driven rotating liquid metal

    International Nuclear Information System (INIS)

    Velikhov, E.P.; Ivanov, A.A.; Zakharov, S.V.; Zakharov, V.S.; Livadny, A.O.; Serebrennikov, K.S.

    2006-01-01

    In view of great importance of magneto-rotational instability (MRI) as a fundamental mechanism for angular momentum transfer in magnetized stellar accretion disks, several research centers are involved in experimental study of MRI under laboratory conditions. The idea of the experiment is to investigate the rotation dynamics of well conducting liquid (liquid metal) between two cylinders in axial magnetic field. In this Letter, an experimental scheme with immovable cylinders and fluid rotation driven by radial current is considered. The analytical solution of a stationary flow was found taking into account the external current. Results of axially symmetric numerical simulations of current driven fluid dynamics in experimental setup geometry are presented. The analytical solution and numerical simulations show that the current driven fluid rotation in axial magnetic field provides the axially homogeneous velocity profile suitable for MRI study in classical statement

  18. Time-resolved crystallization of deeply cooled liquid hydrogen isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Kuehnel, Matthias

    2014-02-15

    This thesis serves two main purposes: 1. The introduction of a novel experimental method to investigate phase change dynamics of supercooled liquids 2. First-time measurements for the crystallization behaviour for hydrogen isotopes under various conditions (1) The new method is established by the synergy of a liquid microjet of ∼ 5 μm diameter and a scattering technique with high spatial resolution, here linear Raman spectroscopy. Due to the high directional stability and the known velocity of the liquid filament, its traveling axis corresponds to a time axis static in space. Utilizing evaporative cooling in a vacuum environment, the propagating liquid cools down rapidly and eventually experiences a phase transition to the crystalline state. This temporal evolution is probed along the filament axis, ultimately resulting in a time resolution of 10 ns. The feasibility of this approach is proven successfully within the following experiments. (2) A main object of study are para-hydrogen liquid filaments. Raman spectra reveal a temperature gradient of the liquid across the filament. This behaviour can quantitatively be reconstructed by numerical simulations using a layered model and is rooted in the effectiveness of evaporative cooling on the surface and a finite thermal conductivity. The deepest supercoolings achieved are ∼ 30% below the melting point, at which the filament starts to solidify from the surface towards the core. With a crystal growth velocity extracted from the data the appropriate growth mechanism is identified. The crystal structure that initially forms is metastable and probably the result of Ostwald's rule of stages. Indications for a transition within the solid towards the stable equilibrium phase support this interpretation. The analog isotope ortho-deuterium is evidenced to behave qualitatively similar with quantitative differences being mass related. In further measurements, isotopic mixtures of para-hydrogen and ortho-deuterium are

  19. Time-resolved crystallization of deeply cooled liquid hydrogen isotopes

    International Nuclear Information System (INIS)

    Kuehnel, Matthias

    2014-02-01

    This thesis serves two main purposes: 1. The introduction of a novel experimental method to investigate phase change dynamics of supercooled liquids 2. First-time measurements for the crystallization behaviour for hydrogen isotopes under various conditions (1) The new method is established by the synergy of a liquid microjet of ∼ 5 μm diameter and a scattering technique with high spatial resolution, here linear Raman spectroscopy. Due to the high directional stability and the known velocity of the liquid filament, its traveling axis corresponds to a time axis static in space. Utilizing evaporative cooling in a vacuum environment, the propagating liquid cools down rapidly and eventually experiences a phase transition to the crystalline state. This temporal evolution is probed along the filament axis, ultimately resulting in a time resolution of 10 ns. The feasibility of this approach is proven successfully within the following experiments. (2) A main object of study are para-hydrogen liquid filaments. Raman spectra reveal a temperature gradient of the liquid across the filament. This behaviour can quantitatively be reconstructed by numerical simulations using a layered model and is rooted in the effectiveness of evaporative cooling on the surface and a finite thermal conductivity. The deepest supercoolings achieved are ∼ 30% below the melting point, at which the filament starts to solidify from the surface towards the core. With a crystal growth velocity extracted from the data the appropriate growth mechanism is identified. The crystal structure that initially forms is metastable and probably the result of Ostwald's rule of stages. Indications for a transition within the solid towards the stable equilibrium phase support this interpretation. The analog isotope ortho-deuterium is evidenced to behave qualitatively similar with quantitative differences being mass related. In further measurements, isotopic mixtures of para-hydrogen and ortho-deuterium are

  20. Time-resolved crystallization of deeply cooled liquid hydrogen isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Kuehnel, Matthias

    2014-02-15

    This thesis serves two main purposes: 1. The introduction of a novel experimental method to investigate phase change dynamics of supercooled liquids 2. First-time measurements for the crystallization behaviour for hydrogen isotopes under various conditions (1) The new method is established by the synergy of a liquid microjet of ∼ 5 μm diameter and a scattering technique with high spatial resolution, here linear Raman spectroscopy. Due to the high directional stability and the known velocity of the liquid filament, its traveling axis corresponds to a time axis static in space. Utilizing evaporative cooling in a vacuum environment, the propagating liquid cools down rapidly and eventually experiences a phase transition to the crystalline state. This temporal evolution is probed along the filament axis, ultimately resulting in a time resolution of 10 ns. The feasibility of this approach is proven successfully within the following experiments. (2) A main object of study are para-hydrogen liquid filaments. Raman spectra reveal a temperature gradient of the liquid across the filament. This behaviour can quantitatively be reconstructed by numerical simulations using a layered model and is rooted in the effectiveness of evaporative cooling on the surface and a finite thermal conductivity. The deepest supercoolings achieved are ∼ 30% below the melting point, at which the filament starts to solidify from the surface towards the core. With a crystal growth velocity extracted from the data the appropriate growth mechanism is identified. The crystal structure that initially forms is metastable and probably the result of Ostwald's rule of stages. Indications for a transition within the solid towards the stable equilibrium phase support this interpretation. The analog isotope ortho-deuterium is evidenced to behave qualitatively similar with quantitative differences being mass related. In further measurements, isotopic mixtures of para-hydrogen and ortho-deuterium are

  1. Design analysis of liquid metal pipe supports

    International Nuclear Information System (INIS)

    Margolin, L.L.; LaSalle, F.R.

    1979-02-01

    Design guidelines pertinent to liquid metal pipe supports are presented. The numerous complex conditions affecting the support stiffness and strength are addressed in detail. Topics covered include modeling of supports for natural frequency and stiffness calculations, support hardware components, formulas for deflection due to torsion, plate bending, and out-of-plane flexibility. A sample analysis and a discussion on stress analysis of supports are included. Also presented are recommendations for design improvements for increasing the stiffness of pipe supports and which were utilized in the FFTF system

  2. Developing remote techniques for liquid metal reactors

    International Nuclear Information System (INIS)

    Fenemore, Peter

    1987-01-01

    Three devices have been designed in Britain to meet the need for special remote equipment and techniques required to inspect the reactor vessel and internals of liquid metal reactors. The ''Links Manipulator Under-Sodium Viewing System'' - a device to be used for the surveillance of reactor internals, which are submerged in sodium. An ''Automatic Guided Vehicle'' - a free roving vehicle to be used to survey the externals of the reactor vessel. The ''Snake Manipulator'' - an articulated arm used to gain access to restricted areas. (author)

  3. Liquid-metal aspects of HYLIFE

    International Nuclear Information System (INIS)

    Meier, W.R.; Hoffman, N.J.; McDowell, M.W.

    1980-01-01

    The High Yield Lithium Injection Fusion Energy (HYLIFE) converter is a reactor concept for an inertial fusion electric power plant. In this concept, flowing molten lithium protects the structures of the fusion chamber from the deleterious effects of deuterium-tritium (DT) fusion reactions and converts the pulsed fusion energy into steay thermal power. Lithium is circulated as the primary coolant to transfer heat to an intermediate sodium loop which drives a superheated steam cycle. Lithium is also the source of the tritium fuel which is recovered via a molten-salt extraction process. The liquid-metal aspects of the HYLIFE plant with particular emphasis on the lithium systems

  4. Hydrogenation of nitriles on a well-characterized nickel surface: From surface science studies to liquid phase catalytic activity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Gardin, Denis Emmanuel [Univ. of California, Berkeley, CA (United States)

    1993-12-01

    Nitrile hydrogenation is the most commonly used method for preparing diverse amines. This thesis is aimed at the mechanism and factors affecting the performance of Ni-based catalysts in nitrile hydrogenations. Surface science techniques are used to study bonding of nitriles and amines to a Ni(111) surface and to identify surface intermediates. Liquid-phase hydrogenations of cyclohexene and 1-hexene on a Pt foil were carried out successfully. Finally, knowledge about the surface structure, surface chemical bond, dynamics of surface atoms (diffusion, growth), and reactivity of metal surfaces from solid-gas interface studies, is discussed.

  5. Hydrogen formation in metals and alloys during fusion reactor operation

    International Nuclear Information System (INIS)

    Zimin, S.; Takatsu, Hideyuki; Mori, Seiji

    1994-08-01

    The results of neutron transport calculations of the hydrogen formation based on the JENDL gas-production cross section file are discussed for some metals and alloys, namely 51 V, Cr, Fe, Ni, Mo, austenitic stainless steel (Ti modified 316SS:PCA), ferritic steel (Fe-8Cr-2W:F82H) and the vanadium-base alloy (V-5Cr-5Ti). Impact of the steel fraction in steel/water homogeneous blanket/shield compositions on the hydrogen formation rate in above-mentioned metals and alloys is discussed both for the hydrogen formation in the first wall and the blanket/shield components. The results obtained for the first wall are compared with those for the helium formation obtained at JAERI by the same calculational conditions. Hydrogen formation rates at the first wall having 51 V, Cr, Fe, Ni and Mo are larger than those of helium by 3-8 times. (author)

  6. Production of Liquid Metal Spheres by Molding

    Directory of Open Access Journals (Sweden)

    Mohammed G. Mohammed

    2014-10-01

    Full Text Available This paper demonstrates a molding technique for producing spheres composed of eutectic gallium-indium (EGaIn with diameters ranging from hundreds of microns to a couple millimeters. The technique starts by spreading EGaIn across an elastomeric sheet featuring cylindrical reservoirs defined by replica molding. The metal flows into these features during spreading. The spontaneous formation of a thin oxide layer on the liquid metal keeps the metal flush inside these reservoirs. Subsequent exposure to acid removes the oxide and causes the metal to bead up into a sphere with a size dictated by the volume of the reservoirs. This technique allows for the production and patterning of droplets with a wide range of volumes, from tens of nanoliters up to a few microliters. EGaIn spheres can be embedded or encased subsequently in polymer matrices using this technique. These spheres may be useful as solder bumps, electrodes, thermal contacts or components in microfluidic devices (valves, switches, pumps. The ease of parallel-processing and the ability to control the location of the droplets during their formation distinguishes this technique.

  7. Performance Gains of Propellant Management Devices for Liquid Hydrogen Depots

    Science.gov (United States)

    Hartwig, Jason W.; McQuillen, John B.; Chato, David J.

    2013-01-01

    This paper presents background, experimental design, and preliminary experimental results for the liquid hydrogen bubble point tests conducted at the Cryogenic Components Cell 7 facility at the NASA Glenn Research Center in Cleveland, Ohio. The purpose of the test series was to investigate the parameters that affect liquid acquisition device (LAD) performance in a liquid hydrogen (LH2) propellant tank, to mitigate risk in the final design of the LAD for the Cryogenic Propellant Storage and Transfer Technology Demonstration Mission, and to provide insight into optimal LAD operation for future LH2 depots. Preliminary test results show an increase in performance and screen retention over the low reference LH2 bubble point value for a 325 2300 screen in three separate ways, thus improving fundamental LH2 LAD performance. By using a finer mesh screen, operating at a colder liquid temperature, and pressurizing with a noncondensible pressurant gas, a significant increase in margin is achieved in bubble point pressure for LH2 screen channel LADs.

  8. Hydrogen storage in metallic hydrides: the hydrides of magnesium-nickel alloys

    International Nuclear Information System (INIS)

    Silva, E.P. da.

    1981-01-01

    The massive and common use of hydrogen as an energy carrier requires an adequate solution to the problem of storing it. High pressure or low temperatures are not entirely satisfactory, having each a limited range of applications. Reversible metal hydrides cover a range of applications intermediate to high pressure gas and low temperature liquid hydrogen, retaining very favorable safety and energy density characteristics, both for mobile and stationary applications. This work demonstrates the technical viability of storing hydrogen in metal hydrides of magnesium-nickel alloys. Also, it shows that technology, a product of science, can be generated within an academic environment, of the goal is clear, the demand outstanding and the means available. We review briefly theoretical models relating to metal hydride properties, specially the thermodynamics properties relevant to this work. We report our experimental results on hydrides of magnesium-nickel alloys of various compositions including data on structure, hydrogen storage capacities, reaction kinetics, pressure-composition isotherms. We selected a promising alloy for mass production, built and tested a modular storage tank based on the hydrides of the alloy, with a capacity for storing 10 Nm sup(3) of hydrogen of 1 atm and 20 sup(0)C. The tank weighs 46,3 Kg and has a volume of 21 l. (author)

  9. Solubility of hydrogen isotopes in stressed hydride-forming metals

    International Nuclear Information System (INIS)

    Coleman, C.E.; Ambler, J.F.R.

    1983-01-01

    Components made from hydride-forming metals can be brittle when particles of hydride are present. The solid solubility limit of hydrogen in these metals needs to be known so that fracture resistance can be properly assessed. Stress affects the solubility of hydrogen in metals. As hydrogen dissolves the metal volume increases, an applied hydrostatic tensile stress supplies work to increase the solubility. Precipitation of hydrides increases the volume further. A hydrostatic tensile stress promotes the formation of hydrides and tends to reduce the terminal solubility. For materials containing hydrogen in solution in equilibrium with hydrides, the effect of stress on the terminal solubility is given. Hydrogen migrates up tensile stress gradients because of the effect of stress on the solubility and solubility limit. Consequently, hydrogen concentrates at flaws. When hydrides are present in the metal matrix, those remote from the flaw tip will preferentially dissolve in favor of those precipitated at the flaw. If the stress is large enough, at some critical condition the hydrides at the flaw will crack. This is delayed hydrogen cracking. Notched and fatigue-cracked cantilever beam specimens (6) (38 x 4 x 3 mm) were machined from the circumferential direction of several cold-worked Zr-2.5 at. % Nb pressure tubes. The chemical compositions had the ranges (in atomic %) Nb - 2.5 to 2.7; O - 0.58 to 0.71; H - 0.018 to 0.18. The effect of test temperature is for a specimen containing 0.13 at. % protium and 0.29 at .% deuterium. Between 505 K and 530 K was less than 1 hr, between 530 K and 537 K it increased to 25.8 h, while at 538 K no cracking was observed up to the 54 h

  10. Study and Development of Face-Contact, Bellows Mechanical Seal for Liquid Hydrogen Turbopump

    OpenAIRE

    NOSAKA, Masataka; SUZUKI, Mineo; MIYAKAWA, Yukio; KAMIJO, Kenjiro; KIKUCHI, Masataka; MORI, Masahiro; 野坂, 正隆; 鈴木, 峰男; 宮川, 行雄; 上絛, 謙二郎; 菊池, 正孝; 森, 雅裕

    1981-01-01

    The development of a 10-ton thrust liquid oxygen and liquid hydrogen (LOX and LH2) rocket engine is under way at the National Space Development Agency. In advance of the development of a liquid hydrogen turbopump, the National Aerospace Laboratory carried out study and development of a face-contact, bellows mechanical seal for a liquid hydrogen turbopump in co-operation with the National Space Development Agency. The present report describes the fundamental experiments of the mechanical seal ...

  11. Ballmilling of metal borohydrides for hydrogen storage

    DEFF Research Database (Denmark)

    Sommer, Sanna

    2014-01-01

    of the renewable energy sources [2]. Borohydrides have received great attention as energy carrier due to their high gravimetric content of hydrogen, though unfortunately they are currently not applicable for industrial use due to high thermal stability and poor recycling. The purpose of the investigation...

  12. Experimental testing facilities for ultrasonic measurements in heavy liquid metal

    International Nuclear Information System (INIS)

    Cojocaru, V.; Ionescu, V.; Nicolescu, D.; Nitu, A.

    2016-01-01

    The thermo-physical properties of Heavy Liquid Metals (HLM), like lead or its alloy, Lead Bismuth Eutectic (LBE), makes them attractive as coolant candidates in advanced nuclear systems. The opaqueness, that is common to all liquid metals, disables all optical methods. For this reason ultrasound waves are used in different applications in heavy liquid metal technology, for example for flow and velocity measurements and for inspection techniques. The practical use of ultrasound in heavy liquid metals still needs to be demonstrated by experiments. This goal requires heavy liquid metal technology facility especially adapted to this task. In this paper is presented an experimental testing facility for investigations of Heavy Liquid Metals acoustic properties, designed and constructed in RATEN ICN. (authors)

  13. Tethered Transition Metals Promoted Photocatalytic System for Efficient Hydrogen Evolutions

    KAUST Repository

    Takanabe, Kazuhiro; Isimjan, Tayirjan; Yu, Weili; Del Gobbo, Silvano; Xu, Wei

    2015-01-01

    The present invention is directed, at least in part, to a process for improving the efficiency of a photocatalyst (a semiconductor photocatalyst) by tethering (depositing) a metal (e.g., metal ions of a late transition metal, such as nickel) to the semiconductor (photocatalyst) surface through the use of an organic ligand. More specifically, 1,2-ethanedithiol (EDT) functions as an excellent molecular linker (organic ligand) to attach a transition metal complex (e.g., nickel (Ni.sup.2+ ions)) to the semiconductor surface, which can be in the form of a cadmium sulfide surface. The photocatalyst has particular utility in generating hydrogen from H.sub.2S.

  14. Tethered Transition Metals Promoted Photocatalytic System for Efficient Hydrogen Evolutions

    KAUST Repository

    Takanabe, Kazuhiro

    2015-03-05

    The present invention is directed, at least in part, to a process for improving the efficiency of a photocatalyst (a semiconductor photocatalyst) by tethering (depositing) a metal (e.g., metal ions of a late transition metal, such as nickel) to the semiconductor (photocatalyst) surface through the use of an organic ligand. More specifically, 1,2-ethanedithiol (EDT) functions as an excellent molecular linker (organic ligand) to attach a transition metal complex (e.g., nickel (Ni.sup.2+ ions)) to the semiconductor surface, which can be in the form of a cadmium sulfide surface. The photocatalyst has particular utility in generating hydrogen from H.sub.2S.

  15. C1 Chemistry for the Production of Ultra-Clean Liquid Transportation Fuels and Hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Gerald P. Huffman

    2006-03-30

    Professors and graduate students from five universities--the University of Kentucky, University of Pittsburgh, University of Utah, West Virginia University, and Auburn University--are collaborating in a research program to develop C1 chemistry processes to produce ultra-clean liquid transportation fuels and hydrogen, the zero-emissions transportation fuel of the future. The feedstocks contain one carbon atom per molecular unit. They include synthesis gas (syngas), a mixture of carbon monoxide and hydrogen produced by coal gasification or reforming of natural gas, methane, methanol, carbon dioxide, and carbon monoxide. An important objective is to develop C1 technology for the production of liquid transportation fuel and hydrogen from domestically plentiful resources such as coal, coalbed methane, and hydrocarbon gases and liquids produced from coal. An Advisory Board with representatives from Chevron-Texaco, Eastman Chemical, Conoco-Phillips, the Air Force Research Laboratory, the U.S. Army National Automotive Center, and Tier Associates provides guidance on the practicality of the research. The current report summarizes the results obtained in this program during the period October 1, 2002 through March 31, 2006. The results are presented in detailed reports on 16 research projects headed by professors at each of the five CFFS Universities and an Executive Summary. Some of the highlights from these results are: (1) Small ({approx}1%) additions of acetylene or other alkynes to the Fischer-Tropsch (F-T) reaction increases its yield, causes chain initiation, and promotes oxygenate formation. (2) The addition of Mo to Fe-Cu-K/AC F-T catalysts improves catalyst lifetime and activity. (3) The use of gas phase deposition to place highly dispersed metal catalysts on silica or ceria aerogels offers promise for both the F-T and the water-gas shift WGS reactions. (4) Improved activity and selectivity are exhibited by Co F-T catalysts in supercritical hexane. (5) Binary Fe

  16. Magnesium nanoparticles with transition metal decoration for hydrogen storage

    International Nuclear Information System (INIS)

    Pasquini, Luca; Callini, Elsa; Brighi, Matteo; Boscherini, Federico; Montone, Amelia; Jensen, Torben R.; Maurizio, Chiara; Vittori Antisari, Marco; Bonetti, Ennio

    2011-01-01

    We report on the hydrogen storage behaviour of Mg nanoparticles (NPs) (size range 100 nm–1 μm) with metal-oxide core–shell morphology synthesized by inert gas condensation and decorated by transition metal (TM) (Pd or Ti) clusters via in situ vacuum deposition. The structure and morphology of the as-prepared and hydrogenated NPs is studied by electron microscopy, X-ray diffraction including in situ experiments and X-ray absorption spectroscopy, in order to investigate the relationships with the hydrogen storage kinetics measured by the volumetric Sieverts method. With both Pd and Ti, the decoration deeply improves the hydrogen sorption properties: previously inert NPs exhibit complete hydrogenation with fast transformation kinetics, good stability and reversible gravimetric capacity that can attain 6 wt%. In the case of Pd-decoration, the occurrence of Mg–Pd alloying is observed at high temperatures and in dependence of the hydrogen pressure conditions. These structural transformations modify both the kinetics and thermodynamics of hydride formation, while Ti-decoration has an effect only on the kinetics. The experimental results are discussed in relation with key issues such as the amount of decoration, the heat of mixing between TM and Mg and the binding energy between TM and hydrogen.

  17. Complex Metal Hydrides for Hydrogen, Thermal and Electrochemical Energy Storage

    DEFF Research Database (Denmark)

    Moller, Kasper T.; Sheppard, Drew; Ravnsbaek, Dorthe B.

    2017-01-01

    Hydrogen has a very diverse chemistry and reacts with most other elements to form compounds, which have fascinating structures, compositions and properties. Complex metal hydrides are a rapidly expanding class of materials, approaching multi-functionality, in particular within the energy storage...... inspiration to solve the great challenge of our time: efficient conversion and large-scale storage of renewable energy....... field. This review illustrates that complex metal hydrides may store hydrogen in the solid state, act as novel battery materials, both as electrolytes and electrode materials, or store solar heat in a more efficient manner as compared to traditional heat storage materials. Furthermore, it is highlighted...

  18. Turbulent convection in liquid metal with and without rotation

    OpenAIRE

    King, Eric M.; Aurnou, Jonathan M.

    2013-01-01

    The magnetic fields of Earth and other planets are generated by turbulent, rotating convection in liquid metal. Liquid metals are peculiar in that they diffuse heat more readily than momentum, quantified by their small Prandtl numbers, . Most analog models of planetary dynamos, however, use moderate fluids, and the systematic influence of reducing is not well understood. We perform rotating Rayleigh–Bénard convection experiments in the liquid metal gallium over a range of nondimensional bu...

  19. Ionic liquids used in extraction and separation of metal ions

    International Nuclear Information System (INIS)

    Shen Xinghai; Xu Chao; Liu Xinqi; Chu Taiwei

    2006-01-01

    Ionic liquids as green solvents now have become a research hotspot in the field of separation of metal ions by solvent extraction. Experimental results of extraction of various metal ions with ionic liquids as solvents, including that of alkali metals, alkaline earths, transition metals rare earths and actinides are introduced. The extraction of uranium, plutonium and fission products that are involved in spent nuclear fuel reprocessing is also reviewed. The possible extraction mechanisms are discussed. Finally, the prospect of replacement of volatile and/or toxic organic solvents with environmentally benign ionic liquids for solvent extraction and the potency of applications of ionic liquids in solvent extraction are also commented. (authors)

  20. Dynamic interactions of Leidenfrost droplets on liquid metal surface

    Science.gov (United States)

    Ding, Yujie; Liu, Jing

    2016-09-01

    Leidenfrost dynamic interaction effects of the isopentane droplets on the surface of heated liquid metal were disclosed. Unlike conventional rigid metal, such conductive and deformable liquid metal surface enables the levitating droplets to demonstrate rather abundant and complex dynamics. The Leidenfrost droplets at different diameters present diverse morphologies and behaviors like rotation and oscillation. Depending on the distance between the evaporating droplets, they attract and repulse each other through the curved surfaces beneath them and their vapor flows. With high boiling point up to 2000 °C, liquid metal offers a unique platform for testing the evaporating properties of a wide variety of liquid even solid.

  1. Utility industry evaluation of the metal fuel facility and metal fuel performance for liquid metal reactors

    International Nuclear Information System (INIS)

    Burstein, S.; Gibbons, J.P.; High, M.D.; O'Boyle, D.R.; Pickens, T.A.; Pilmer, D.F.; Tomonto, J.R.; Weinberg, C.J.

    1990-02-01

    A team of utility industry representatives evaluated the liquid metal reactor metal fuel process and facility conceptual design being developed by Argonne National Laboratory (ANL) under Department of Energy sponsorship. The utility team concluded that a highly competent ANL team was making impressive progress in developing high performance advanced metal fuel and an economic processing and fabrication technology. The utility team concluded that the potential benefits of advanced metal fuel justified the development program, but that, at this early stage, there are considerable uncertainties in predicting the net overall economic benefit of metal fuel. Specific comments and recommendations are provided as a contribution towards enhancing the development program. 6 refs

  2. Softening of metals under hydrogen ion irradiation

    International Nuclear Information System (INIS)

    Guseva, M.I.; Korshunov, S.N.; Martynenko, Yu.V.; Skorlupkin, I.D.

    2005-01-01

    Experimental study results are presented on steel type 18-10 creep under hydrogen ion irradiation. The Irradiation of annealed specimens is accomplished by 15 keV H 2 + ions with a dose up to 10 22 m -2 at current density of 0.6 A/m 2 at temperatures of 570-770 K. Creep tests show that the irradiation at T = 770 K results in a sharp increase of creep rate. At t 570 K the effect of ion-induced creep in steel 18-10 is not observed. The model is proposed which explains the ion-induced creep by accumulation of hydrogen along grain boundaries, their weakening and removal of obstacles to sliding [ru

  3. Engineering: Liquid metal pumped at a record temperature

    Science.gov (United States)

    Lambrinou, Konstantina

    2017-10-01

    Although liquid metals are effective fluids for heat transfer, pumping them at high temperatures is limited by their corrosiveness to solid metals. A clever pump design addresses this challenge using only ceramics. See Article p.199

  4. Electronic transport coefficients from ab initio simulations and application to dense liquid hydrogen

    International Nuclear Information System (INIS)

    Holst, Bastian; French, Martin; Redmer, Ronald

    2011-01-01

    Using Kubo's linear response theory, we derive expressions for the frequency-dependent electrical conductivity (Kubo-Greenwood formula), thermopower, and thermal conductivity in a strongly correlated electron system. These are evaluated within ab initio molecular dynamics simulations in order to study the thermoelectric transport coefficients in dense liquid hydrogen, especially near the nonmetal-to-metal transition region. We also observe significant deviations from the widely used Wiedemann-Franz law, which is strictly valid only for degenerate systems, and give an estimate for its valid scope of application toward lower densities.

  5. Composite metal-hydrogen electrodes for metal-hydrogen batteries. Final report, October 1, 1993 - April 15, 1997

    International Nuclear Information System (INIS)

    Ruckman, M.W.; Strongin, M.; Weismann, H.

    1997-04-01

    The purpose of this project is to develop and conduct a feasibility study of metallic thin films (multilayered and alloy composition) produced by advanced sputtering techniques for use as anodes in Ni-metal hydrogen batteries that would be deposited as distinct anode, electrolyte and cathode layers in thin film devices. The materials could also be incorporated in secondary consumer batteries (i.e. type AF(4/3 or 4/5)) which use electrodes in the form of tapes. The project was based on pioneering studies of hydrogen uptake by ultra-thin Pd-capped Nb films, these studies suggested that materials with metal-hydrogen ratios exceeding those of commercially available metal hydride materials and fast hydrogen charging and discharging kinetics could be produced. The project initially concentrated on gas phase and electrochemical studies of Pd-capped niobium films in laboratory-scale NiMH cells. This extended the pioneering work to the wet electrochemical environment of NiMH batteries and exploited advanced synchrotron radiation techniques not available during the earlier work to conduct in-situ studies of such materials during hydrogen charging and discharging. Although batteries with fast charging kinetics and hydrogen-metal ratios approaching unity could be fabricated, it was found that oxidation, cracking and corrosion in aqueous solutions made pure Nb films and multilayers poor candidates for battery application. The project emphasis shifted to alloy films based on known elemental materials used for NiMH batteries. Although commercial NiMH anode materials contain many metals, it was found that 0.24 μm thick sputtered Zr-Ni films cycled at least 50 times with charging efficiencies exceeding 95% and [H]/[M] ratios of 0.7-1.0. Multilayered or thicker Zr-Ni films could be candidates for a thin film NiMH battery that may have practical applications as an integrated power source for modern electronic devices

  6. Study of liquid hydrogen and liquid deuterium cold neutron sources; Etude de sources de neutrons froids a hydrogene et deuterium liquides

    Energy Technology Data Exchange (ETDEWEB)

    Harig, H D [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1967-12-01

    In view of the plant of the cold neutron source for a high flux reactor (maximal thermal flux of about 10{sup 15} n/cm{sup 2}s) an experimental study of several cold sources of liquid hydrogen and liquid deuterium has been made in a low power reactor (100 kW, about 10{sup 12} n/cm{sup 2}s). We have investigated: -cold neutron sources of liquid hydrogen shaped as annular layers of different thickness. Normal liquid hydrogen was used as well as hydrogen with a high para-percentage. -Cold neutron sources of liquid deuterium in cylinders of 18 and 38 cm diameter. In this case the sources could be placed into different positions to the reactor core within the heavy water reflector. This report gives a general description of the experimental device and deals more detailed with the design of the cryogenic systems. Then, the measured results are communicated, interpreted and finally compared with those of a theoretical study about the same cold moderators which have been the matter of the experimental investigation. (authors) [French] En vue de l'installation d'une source a neutrons froids dans un reacteur a haut flux (flux thermique maximal environ 10{sup 15} n/cm{sup 2}s), nous avons fait une etude neutronique experimentale de differentes sources froides a hydrogene et a deuterium liquides aupres d'un reacteur a faible puissance (100 kW environ 10{sup 12} n/cm{sup 2}s). Nous avons etudie: des couches annulaires de differentes epaisseurs d'hydrogene liquide normal et d'hydrogene a grand pourcentage para, des cellules cylindriques de 18 et 38 cm de diametre, remplies de deuterium liquide et placees a differentes positions dans le reflecteur D{sub 2}O. Ce travail traite l'implantation de l'installation cryogenique et donne une description generale de l'experience. L'interpretation des resultats fait etat entre autres d'une comparaison entre l'experience et une etude theorique portant sur les memes moderateurs. (auteurs)

  7. Microstructured liquid metal electron and ion sources (MILMES/MILMIS)

    Energy Technology Data Exchange (ETDEWEB)

    Mitterauer, J [Technische Universitaet Wien (Austria). Institut fuer Allgemeine Elektrotechnik und Elektronik

    1997-12-31

    Ion or electron beams can be emitted from liquid metal wetted needles, or from capillaries or slits into which the liquid metal is allowed to flow. Large-area liquid metal field emission sources have been proposed recently, using either two-dimensional, regular arrays of cones or capillaries, or even a substrate with an intrinsically microstructured surface covered by a liquid metal film. This latter concept has been realized in a pilot experiment by in situ wicking and wetting of a porous sintered metal disc. Microstructured liquid metal ion or electron sources are capable of operating in a pulsed mode at a current level which is orders of magnitude above that for steady-state operation. (author). 3 figs., 10 refs.

  8. Archive-cup insert for liquid-metal sampling

    International Nuclear Information System (INIS)

    Nelson, P.A.; Kolba, V.M.; Filewicz, E.C.; Holmes, J.T.

    1975-01-01

    An insert for collecting liquid-metal samples within a vertical casing including an elongated housing with an upper and a lower overflow seal of annular shape is described. The lower seal includes a centrally located pedestal on which a sample cup is disposed. Liquid metal enters the annulus of the upper seal and overflows into the cup which fills and overflows into the lower seal. Liquid-metal overflow from the lower seal is discharged from the insert. On cooling, the liquid metal trapped within the seals solidifies to hermetically isolate the metal sample within the cup. The device is particularly applicable for use with sampling systems on liquid metal-cooled reactors. (U.S.)

  9. Organic chemical hydrides as storage medium of hydrogen on the basis of superheated liquid-film concept

    International Nuclear Information System (INIS)

    Shinya Hodoshima; Atsushi Shono; Kazumi Satoh; Yasukazu Saito

    2006-01-01

    A catalysis pair of tetralin dehydrogenation / naphthalene hydrogenation has been proposed in the present paper as an organic chemical hydride for operating stationary fuel cells. Catalytic naphthalene hydrogenation, having been commercialized since the 1940's, proceeds to generate decalin via tetralin as an intermediate. The storage capacities of tetralin (3.0 wt%, 28.2 kg-H 2 / m 3 ) are lower than decalin (7.3 wt%, 64.8 kg-H 2 / m 3 ) but both tetralin dehydrogenation and naphthalene hydrogenation are much faster than the decalin / naphthalene pair. Moreover, existing infrastructures, e.g., gas station and tank lorry, are available for storage, transportation and supply of hydrogen. As for the stationary fuel cells with large space for hydrogen storage, tetralin as a hydrogen carrier is superior to decalin in terms of fast hydrogen supply. Rapid hydrogen supply from tetralin under mild conditions was only accomplished with the carbon supported metal catalysts in the 'superheated liquid-film states' under reactive distillation conditions. In contrast to the ordinary suspended states, the catalyst layer superheated in the liquid-film state gave high catalytic performances at around 250 C. As a result, serious coke formation over the catalyst surface and excessive exergy consumption were prevented simultaneously. (authors)

  10. Development of composite metallic membranes for hydrogen purification

    International Nuclear Information System (INIS)

    Gaillard, F.

    2003-12-01

    Fuel cells are able to convert chemical energy into electric power. There are different types of cells; the best for automotive applications are Proton Exchange Membrane Fuel Cells. But, these systems need hydrogen of high purity. However, fuel reforming generates a mixture of gases, from which hydrogen has to be extracted before supplying the electrochemical cell. The best way for the purification of hydrogen is the membrane separation technology. Palladium is selectively permeable to hydrogen and this is the reason why this metal is largely used for the membrane development. This work deals with the development of hydrogen-selective membranes by deposition of a thin film of palladium onto a porous mechanical support. For this, we have used the electroless plating technique: a palladium salt and a reducing agent are mixed and the deposition takes place onto the catalytic surface of the substrate. After bibliographic investigations, experimental studies have been performed first with a dense metallic substrate in order to better understand the different parameters controlling the deposition. First of all, potentiometric measurements have been carried out to follow the electrochemical reactions in the bath. Then, kinetic measurements of the coating thickness have been recorded to understand the effect of the bath conditions on the yield and the adhesion of the film. Finally, the electroless plating method has been applied to deposit palladium membranes onto porous stainless steel substrates. After optimisation, the resulting membranes were tested for their hydrogen permeation properties. (author)

  11. Hydrogen gettering the overpressure gas from highly radioactive liquids

    International Nuclear Information System (INIS)

    Riley, D.L.; Schicker, J.R.

    1996-04-01

    Remediation of current inventories of high-activity radioactive liquid waste (HALW) requires transportation of Type-B quantities of radioactive material, possibly up to several hundred liters. However, the only currently certified packaging is limited to quantities of 50 ml (0.01 gal) quantities of Type-B radioactive liquid. Efforts are under way to recertify the existing packaging to allow the shipment of up to 4 L (1.1 gal) of Type-B quantities of HALW, but significantly larger packaging could be needed in the future. Scoping studies and preliminary designs have identified the feasibility of retrofitting an insert into existing casks, allowing the transport of up to 380 L (100 gal) of HALW. However, the insert design and ultimate certification strategy depend heavily on the gas-generating attributes of the HALW. A non-vented containment vessel filled with HALW, in the absence of any gas-mitigation technologies, poses a deflagration threat and, therefore, gas generation, specifically hydrogen generation, must be reliably controlled during all phases of transportation. Two techniques are available to mitigate hydrogen accumulation: recombiners and getters. Getters have an advantage over recombiners in that oxides are not required to react with the hydrogen. A test plan was developed to evaluate three forms of getter material in the presence of both simulated HALW and the gases that are produced by the HALW. These tests demonstrated that getters can react with hydrogen in the presence of simulated waste and in the presence of several other gases generated by the HALW, such as nitrogen, ammonia, nitrous oxide, and carbon monoxide. Although the use of such a gettering system has been shown to be technically feasible, only a preliminary design for its use has been completed. No further development is planned until the requirement for bulk transport of Type-B quantities of HALW is more thoroughly defined

  12. Hydrogen storage alloys for nickel/metal hydride battery

    Energy Technology Data Exchange (ETDEWEB)

    Kuriyama, Nobuhiro; Sakai, Tetsuo; Myamura, Hiroshi; Tanaka, Hideaki; Ishikawa, Hiroshi; Uehara, Itsuki [Osaka National Research Inst. (Japan)

    1996-06-01

    Efforts to improve performance of metal hydride electrodes such as substitution of alloy components, heat treatment, and surface treatment intended to change surface and bulk structure of hydrogen storage alloys, mainly LaNi{sub 5} based alloys, are reviewed. The importance of control of morphology is emphasized. (author)

  13. Cascades for hydrogen isotope separation using metal hydrides

    International Nuclear Information System (INIS)

    Hill, F.B.; Grzetic, V.

    1982-01-01

    Designs are presented for continuous countercurrent hydrogen isotope separation cascades based on the use of metal hydrides. The cascades are made up of pressure swing adsorption (PSA) or temperature swing adsorption (TSA) stages. The designs were evolved from consideration of previously conducted studies of the separation performance of four types of PSA and TSA processes

  14. Removal of heavy metal from industrial wastewater using hydrogen ...

    African Journals Online (AJOL)

    The batch removal of heavy metals lead (Pb), zinc (Zn) and copper (Cu) from industrial wastewater effluent under different experimental conditions using hydrogen peroxide was investigated. Experimental results indicated that at pH 6.5, pre-treatment analysis gave the following values: Pb 57.63 mg/l, Zn 18.9 mg/l and Cu ...

  15. Cascades for hydrogen isotope separation using metal hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Hill, F B; Grzetic, V [Brookhaven National Lab., Upton, NY (USA)

    1983-02-01

    Designs are presented for continuous countercurrent hydrogen isotope separation cascades based on the use of metal hydrides. The cascades are made up of pressure swing adsorption (PSA) or temperature swing adsorption (TSA) stages. The designs were evolved from consideration of previously conducted studies of the separation performance of four types of PSA and TSA processes.

  16. Biomass transition metal hydrogen-evolution electrocatalysts and electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wei-Fu; Iyer, Shweta; Iyer, Shilpa; Sasaki, Kotaro; Muckerman, James T.; Fujita, Etsuko

    2017-02-28

    A catalytic composition from earth-abundant transition metal salts and biomass is disclosed. A calcined catalytic composition formed from soybean powder and ammonium molybdate is specifically exemplified herein. Methods for making the catalytic composition are disclosed as are electrodes for hydrogen evolution reactions comprising the catalytic composition.

  17. Hydrogen evolution on nano-particulate transition metal sulfides

    DEFF Research Database (Denmark)

    Bonde, Jacob Lindner; Moses, Poul Georg; Jaramillo, Thomas F.

    2008-01-01

    The hydrogen evolution reaction (HER) on carbon supported MoS2 nanoparticles is investigated and compared to findings with previously published work on Au(111) supported MoS2. An investigation into MoS2 oxidation is presented and used to quantify the surface concentration of MoS2. Other metal sul...

  18. Fundamental study on cavitation erosion in liquid metal. Effect of liquid parameter on cavitation erosion in liquid metals (Joint research)

    International Nuclear Information System (INIS)

    Hattori, Shuji; Kurachi, Hiroaki; Inoue, Fumitaka; Watashi, Katsumi; Tsukimori, Kazuyuki; Yada, Hiroki; Hashimoto, Takashi

    2009-02-01

    Cavitation erosion, which possibly occurs on the surfaces of fluid machineries and components contacting flowing liquid and causes sponge-like damage on the material surface, is important problem, since it may become the cause of performance deduction, life shortening, noise, vibration of mechanical components and moreover failure of machine. Research on cavitation erosion in liquid metal is very important to confirm the safety of fast breeder reactor using sodium coolant and to avoid serious damage of the target vessel of spallation neutron source containing liquid-mercury. But the research on cavitation erosion in liquid metal has been hardly performed because of its specially in comparison with that in water. In this study, a cavitation erosion test apparatus was developed to carry out the erosion tests in low-temperature liquid metals. Cavitation erosion tests were carried out in liquid lead-bismuth alloy and in deionized water. We discuss the effect of liquid parameters and temperature effects on the erosion rate. We reach to the following conclusions. The erosion rate was evaluated in terms of a relative temperature which was defind as the percentage between freezing and boiling points. At 14degC relative temperature, the erosion rate is 10 times in lead-bismuth alloy, and 2 to 5 times in sodium, compared with that in deionized water. At 14degC relative temperature, the erosion rate can be evaluated in terms of the following parameter. 1 / (1/ρ L /C L +1/ρ S C S )√ρ L . Where ρ is the material density and c is the velocity of sound, L and S denote liquid and solid. In the relative temperature between 14 and 30degC, the temperature dependence on the erosion rate is due to the increase in vapor pressure. (author)

  19. Thermophysical properties of hydrogen along the liquid-vapor coexistence

    Science.gov (United States)

    Osman, S. M.; Sulaiman, N.; Bahaa Khedr, M.

    2016-05-01

    We present Theoretical Calculations for the Liquid-Vapor Coexistence (LVC) curve of fluid Hydrogen within the first order perturbation theory with a suitable first order quantum correction to the free energy. In the present equation of state, we incorporate the dimerization of H2 molecule by treating the fluid as a hard convex body fluid. The thermophysical properties of fluid H2 along the LVC curve, including the pressure-temperature dependence, density-temperature asymmetry, volume expansivity, entropy and enthalpy, are calculated and compared with computer simulation and empirical results.

  20. A liquid organic carrier of hydrogen as a fuel for automobiles

    International Nuclear Information System (INIS)

    Taube, M.; Taube, P.

    1979-09-01

    A system of storing energy in a hydrogen containing fuel for the motor car is discussed. The recyclable liquid chemical carrier is: (Methylcyclohexane (liquid)) dehydrogenation (Toluene (liquid)) + (hydrogen (gas)). The reverse reaction, the hydrogenation of toluene, occurs in a regional plant connected to a source of hydrogen (electrolysis of water) with a significant by-product being heat at 200 0 C for district heating. The system is able to store hydrogen in liquid form under ambient temperature and pressure even in a small motor car. The concentration of hydrogen is 6.1 % by weight. The release of gaseous hydrogen from the liquid methylcyclohexane needs a chemical catalytic reactor having a temperature of 300 0 C and a pressure of some bars. This reaction has been well studied. The thermal energy for the dehydrogenation is taken from the exhaust gases at 780 0 C. A layout of the most important processes of the system is given. (Auth.)

  1. Radionuclide trap for liquid metal cooled reactors

    International Nuclear Information System (INIS)

    McGuire, J.C.; Brehm, W.F.

    1978-10-01

    At liquid metal cooled reactor operating temperatures, radioactive corrosion product transport and deposition in the primary system will be sufficiently high to limit access time for maintenance of system components. A radionuclide trap has been developed to aid in controlling radioactivity transport. This is a device which is located above the reactor core and which acts as a getter, physically immobilizing radioactive corrosion products, particularly 54 Mn. Nickel is the getter material used. It is most effective at temperatures above 450 0 C and effectiveness increases with increasing temperature. Prototype traps have been tested in sodium loops for 40,000 hours at reactor primary temperatures and sodium velocities. Several possible in-reactor trap sites were considered but a location within the top of each driver assembly was chosen as the most convenient and effective. In this position the trap is changed each time fuel is changed

  2. Liquid metal cooled fast breeder nuclear reactors

    International Nuclear Information System (INIS)

    Duncombe, E.; Thatcher, G.

    1979-01-01

    The invention described relates to a liquid metal cooled fast breeder nuclear reactor in which the fuel assembly has an inner zone comprised mainly of fissile material and a surrounding outer zone comprised mainly of breeder material. According to the invention the sub-assemblies in the outer zone include electro-magnetic braking devices (magnets, pole pieces and armature) for regulating the flow of coolant through the sub-assemblies. The magnetic fields of the electro-magnetic breaking devices are temperature sensitive so that as the power output of the breeder sub-assemblies increases the electro-magnetic resistance to coolant flow is reduced thereby maintaining the temperature of the coolant outlets from the sub-assemblies substantially constant. (UK)

  3. Generation of electricity using liquid metal magnetohydrodynamics

    International Nuclear Information System (INIS)

    Goodwin, F.E.

    1992-01-01

    With liquid metal magnetohydrodynamics, a column of molten lead is passed through a magnetic field, thereby generating a voltage potential according to Faraday's law. The molten lead is propelled through a closed loop by steam from water injected just above where the lead is heated at the bottom of the loop. This water in turn boils explosively, propelling the lead upward through the loop and past the point where the steam escapes through a separator. Electricity can be generated more efficiently from steam with LMMHD than with conventional turbines. With the DC current generated by LMMHD, industriell cogeneration is seen as the most likely application, where the byproduct steam still has enough pressure to also power other steam-driven machinery. Furthermore, the byproduct steam is essentially lead-free since the operating temperature of the LMMHD generator is well below the temperature where lead could dissolve into the steam. (orig.) [de

  4. Flow balancing in liquid metal blankets

    International Nuclear Information System (INIS)

    Tillack, M.S.; Morley, N.B.

    1995-01-01

    Non-uniform flow distribution between parallel channels is one of the most serious concerns for self-cooled liquid metal blankets with electrically insulated walls. We show that uncertainties in flow distribution can be dramatically reduced by relatively simple design modifications. Several design features which impose flow uniformity by electrically coupling parallel channels are surveyed. Basic mechanisms for ''flow balancing'' are described, and a particular self-regulating concept using discrete passive electrodes is proposed for the US ITER advanced blanket concept. Scoping calculations suggest that this simple technique can be very powerful in equalizing the flow, even with massive insulator failures in individual channels. More detailed analyses and experimental verification will be required to demonstrate this concept for ITER. (orig.)

  5. A study on metal organic framework (MOF-177) synthesis, characterization and hydrogen adsorption -desorption cycles

    Energy Technology Data Exchange (ETDEWEB)

    Viditha, V.; Venkateswer Rao, M.; Srilatha, K.; Himabindu, V. [Centre for Environment, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad-500 085, A.P. (India); Yerramilli, Anjaneyulu [Director, TLGVRC, JSU Box 18739, JSU, Jackson, MS 32917-0939 (United States)

    2013-07-01

    Hydrogen has long been considered to be an ideal alternative to fossil-fuel systems and much work has now been done on its storage. There are four main methods of hydrogen storage: as a liquid; as compressed hydrogen; in the form of metal hydrides; and by physisorption. Among all the materials metal organic frameworks (MOFs) are considered to have desirable properties like high porosity, pore volume and high thermal stability. MOF-177 is considered to be an ideal storage material. In this paper we study about its synthesis and hydrogen storage capacities of MOF-177 at different pressures ranging from 25, 50, 75 and 100 bar respectively. The obtained samples are characterized by XRD, BET and SEM. The recorded results show that the obtained hydrogen capacity is 1.1, 2.20, 2.4 and 2.80 wt%. The desorption capacity is 0.9, 2.1, 2.37 and 2.7 wt% at certain temperatures like 373 K.

  6. Liquid metal tribology in fast breeder reactors

    International Nuclear Information System (INIS)

    Wild, E.; Mack, K.J.; Gegenheimer, M.

    1984-11-01

    Liquid Metal Cooled Fast Breeder Reactors (LMFBR) require mechanisms operating in various sodium liquid and sodium vapor environments for extended periods of time up to temperatures of 900 K under different chemical properties of the fluid. The design of tribological systems in those reactors cannot be based on data and past experience of so-called conventional tribology. Although basic tribological phenomena and their scientific interpretation apply in this field, operating conditions specific to nuclear reactors and prevailing especially in the nuclear part of such facilities pose special problems. Therefore, in the framework of the R and D-program accompanying the construction phase of SNR 300 experiments were carried out to provide data and knowledge necessary for the lay-out of friction systems between mating surfaces of contacting components. Initially, screening tests isolated material pairs with good slipping properties and maximum wear resistance. Those materials were subjected to comprehensive parameter investigations. A multitude of laboratory scale tests have been performed under largely reactor specific conditions. Unusual superimpositions of parameters were analyzed and separated to find their individual influence on the friction process. The results of these experiments were made available to the reactor industry as well as to factories producing special tribo-materials. (orig.) [de

  7. Insulator-metal transition of fluid molecular hydrogen

    International Nuclear Information System (INIS)

    Ross, M.

    1996-01-01

    Dynamically compressed fluid hydrogen shows evidence for metallization at the relatively low pressure of 140 GPa (1.4 Mbar) while experiments on solid hydrogen made in a diamond-anvil cell have failed to detect any evidence for gap closure up to a pressure of 230 GPa (2.3 Mbar). Two possible mechanisms for metal- liclike resistivity are put forward. The first is that as a consequence of the large thermal disorder in the fluid (kT∼0.2 endash 0.3 eV) short-range molecular interactions lead to band tailing that extends the band edge into the gap, resulting in closure at a lower pressure than in the solid. The second mechanism argues that molecular dissociation creates H atoms that behave similar to n-type donors in a heavily doped semiconductor and undergo a nonmetal-metal Mott-type transition. copyright 1996 The American Physical Society

  8. Progress of liquid metal technology and application in energy industries

    International Nuclear Information System (INIS)

    Miyazaki, Keiji; Kamei, Mitsuru; Nei, Hiromichi.

    1990-01-01

    Liquid metals are excellent energy transport media, and recently remarkable development has been observed in the technology of handling sodium and the machinery and equipment. In nuclear fusion, the development of the use of lithium as the coolant is advanced. For space technology, attention has been paid from the early stage to various liquid metals. For general industries, liquid metals have been used for high temperature heat pipes and the utilization of solar heat, and mercury vapor turbines were manufactured for trial. Besides, attention is paid anew to liquid metal MHD electric power generation. The development of the NaS batteries for electric cars and electric power storage and the interchange of liquid metal technology with the fields of iron and steel, metallurgy and so on advance. It is expected that liquid metal technology bears future advanced energy engineering while deepening the interchange with other advanced fields also in order to reactivate atomic energy technology. Liquid metals have the features of high electric and thermal conductivities, chemical activity and opaque property as metals, and fluidity and relatively high boiling point and melting point as liquids. FBRs, fusion reactors and the power sources for space use are described. (K.I.)

  9. Novel routes to metal nanoparticles : electrodeposition and reactions at liquid-liquid interfaces

    OpenAIRE

    Johans, Christoffer

    2003-01-01

    This thesis considers the nucleation and growth, synthesis, and catalytic application of metallic nanoparticles at liquid|liquid interfaces. It comprises five publications, a previously unpublished synthesis of polymer coated palladium nanoparticles, and an introduction to the relevant literature. Three publications are concerned with electrodeposition of metal nanoparticles at liquid|liquid interfaces. One publication and the results presented here consider the synthesis of silver and pallad...

  10. Ionic imbalance induced self-propulsion of liquid metals

    Science.gov (United States)

    Zavabeti, Ali; Daeneke, Torben; Chrimes, Adam F.; O'Mullane, Anthony P.; Zhen Ou, Jian; Mitchell, Arnan; Khoshmanesh, Khashayar; Kalantar-Zadeh, Kourosh

    2016-08-01

    Components with self-propelling abilities are important building blocks of small autonomous systems and the characteristics of liquid metals are capable of fulfilling self-propulsion criteria. To date, there has been no exploration regarding the effect of electrolyte ionic content surrounding a liquid metal for symmetry breaking that generates motion. Here we show the controlled actuation of liquid metal droplets using only the ionic properties of the aqueous electrolyte. We demonstrate that pH or ionic concentration gradients across a liquid metal droplet induce both deformation and surface Marangoni flow. We show that the Lippmann dominated deformation results in maximum velocity for the self-propulsion of liquid metal droplets and illustrate several key applications, which take advantage of such electrolyte-induced motion. With this finding, it is possible to conceive the propulsion of small entities that are constructed and controlled entirely with fluids, progressing towards more advanced soft systems.

  11. Method of charging instruments into liquid metal coolant

    International Nuclear Information System (INIS)

    Yamazaki, Hiroshi

    1980-01-01

    Purpose: To alleviate the thermal shock of a reactor charging machine when charging the machine into liquid metal coolant after the machine is preheated in cover gas. Method: When a reactor fueling machine reaches at the lowermost portion the position immediately above liquid metal coolant surface level, the machine is stopped moving down. The reactor fueling machine is heated at the lowermost portion by thermal radiation from the surface of the liquid metal coolant. After the machine is thus preheated in cover gas, it is again steadily moved down by a winch and charged into the liquid metal coolant. Therefore, the thermal shock of the machine becomes low when charging the machine into the liquid metal coolant to eliminate the damage and deformation at the machine. (Yoshihara, H.)

  12. Measurement of the differential pressure of liquid metals

    Science.gov (United States)

    Metz, H.J.

    1975-09-01

    This patent relates to an improved means for measuring the differential pressure between any two points in a process liquid metal coolant loop, wherein the flow of liquid metal in a pipe is opposed by a permanent magnet liquid metal pump until there is almost zero flow shown by a magnetic type flowmeter. The pressure producing the liquid metal flow is inferred from the rate of rotation of the permanent magnet pump. In an alternate embodiment, a differential pressure transducer is coupled to a process pipeline by means of high-temperature bellows or diaphragm seals, and a permanent magnet liquid metal pump in the high-pressure transmission line to the pressure transducer can be utilized either for calibration of the transducer or for determining the process differential pressure as a function of the magnet pump speed. (auth)

  13. Measurement of the differential pressure of liquid metals

    International Nuclear Information System (INIS)

    Metz, H.J.

    1975-01-01

    This patent relates to an improved means for measuring the differential pressure between any two points in a process liquid metal coolant loop, wherein the flow of liquid metal in a pipe is opposed by a permanent magnet liquid metal pump until there is almost zero flow shown by a magnetic type flowmeter. The pressure producing the liquid metal flow is inferred from the rate of rotation of the permanent magnet pump. In an alternate embodiment, a differential pressure transducer is coupled to a process pipeline by means of high-temperature bellows or diaphragm seals, and a permanent magnet liquid metal pump in the high-pressure transmission line to the pressure transducer can be utilized either for calibration of the transducer or for determining the process differential pressure as a function of the magnet pump speed

  14. Photoionization microscopy of hydrogen atom near a metal surface

    International Nuclear Information System (INIS)

    Yang Hai-Feng; Wang Lei; Liu Xiao-Jun; Liu Hong-Ping

    2011-01-01

    We have studied the ionization of Rydberg hydrogen atom near a metal surface with a semiclassical analysis of photoionization microscopy. Interference patterns of the electron radial distribution are calculated at different scaled energies above the classical saddle point and at various atom—surface distances. We find that different types of trajectories contribute predominantly to different manifolds in a certain interference pattern. As the scaled energy increases, the structure of the interference pattern evolves smoothly and more types of trajectories emerge. As the atom approaches the metal surface closer, there are more types of trajectories contributing to the interference pattern as well. When the Rydberg atom comes very close to the metal surface or the scaled energy approaches the zero field ionization energy, the potential induced by the metal surface will make atomic system chaotic. The results also show that atoms near a metal surface exhibit similar properties like the atoms in the parallel electric and magnetic fields. (atomic and molecular physics)

  15. Liquid alternative diesel fuels with high hydrogen content

    Energy Technology Data Exchange (ETDEWEB)

    Hancsok, Jenoe; Varga, Zoltan; Eller, Zoltan; Poelczmann, Gyoergy [Pannonia Univ., Veszprem (Hungary). MOL Dept. of Hydrocarbon Processing; Kasza, Tamas [MOL Hungarian Oil and Gas Plc., Szazhalombatta (Hungary)

    2013-06-01

    Mobility is a keystone of the sustainable development. In the operation of the vehicles as the tools of mobility internal combustion engines, so thus Diesel engines will play a remarkable role in the next decades. Beside fossil fuels - used for power these engines - liquid alternative fuels have higher and higher importance, because of their known advantages. During the presentation the categorization possibilities based on the chronology of their development and application will be presented. The importance of fuels with high hydrogen content will be reviewed. Research and development activity in the field of such kind of fuels will be presented. During this developed catalytic systems and main performance properties of the product will be presented which were obtained in case of biogasoils produced by special hydrocracking of natural triglycerides and in case of necessity followed by isomerization; furthermore in case of synthetic biogasoils obtained by the isomerization hydrocracking of Fischer-Tropsch paraffins produced from biomass based synthesis gas. Excellent combustion properties (cetane number > 65-75), good cold flow properties and reduced harmful material emission due to the high hydrogen content (C{sub n}H{sub 2n+2}) are highlighted. Finally production possibilities of linear and branched paraffins based on lignocelluloses are briefly reviewed. Summarizing it was concluded that liquid hydrocarbons with high isoparaffin content are the most suitable fuels regarding availability, economical and environmental aspects, namely the sustainable development. (orig.)

  16. Many-Body Potentials For Binary Immiscible liquid Metal Alloys

    International Nuclear Information System (INIS)

    Karaguelle, H.

    2004-01-01

    The modified analytic embedded atom method (MAEAM) type many- body potentials have been constructed for three binary liquid immiscible alloy systems: Al-Pb, Ag-Ni, Ag- Cu. The MAEAM potential functions are fitted to both solid and liquid state properties for only liquid pure metals which consist the immiscible alloy. In order to test the reliability of the constructed MAEAM effective potentials, partial structure factors and pair distribution functions of these binary liquid metal alloys have been calculated using the thermodynamically self-consistent variational modified hypernetted chain (VMHNC) theory of liquids. A good agreement with the available experimental data for structure has

  17. Bulk viscosity and ultrasonic attenuation in liquid metals

    International Nuclear Information System (INIS)

    Awasthi, O.N.; Murthy, B.V.S.

    1984-11-01

    Ultrasonic attenuation in simple liquid metals has been investigated using the thermodynamic theory of relaxation processes incorporating the concept of a two state model for the liquid near the melting point. Agreement of the results with the experimental values of the ultrasonic attenuation and bulk viscosity indicates that this might be an appropriate approach to explain the excess attenuation of ultrasonic waves in liquid metals. (author)

  18. A neutronic method to determine low hydrogen concentrations in metals

    International Nuclear Information System (INIS)

    Bennun, Leonardo; Santisteban, Javier; Diaz-Valdes, J.; Granada, J.R.; Mayer, R.E.

    2007-01-01

    We propose a method for the non-destructive determination of low hydrogen content in metals. The method is based on measurements of neutron inelastic scattering combined with cadmium filters. Determination is simple and the method would allow to construct a mobile device, to perform the analysis 'in situ'. We give a brief description of the usual methods to determine low hydrogen contents in solids, paying special attention to those methods supported by neutron techniques. We describe the proposed method, calculations to achieve a better sensitivity, and experimental results

  19. Liquid metal actuation by electrical control of interfacial tension

    Energy Technology Data Exchange (ETDEWEB)

    Eaker, Collin B.; Dickey, Michael D., E-mail: michael-dickey@ncsu.edu [Department of Chemical and Biomolecular Engineering, North Carolina State University, 911 Partners Way, Raleigh, North Carolina 27695 (United States)

    2016-09-15

    By combining metallic electrical conductivity with low viscosity, liquid metals and liquid metal alloys offer new and exciting opportunities to serve as reconfigurable components of electronic, microfluidic, and electromagnetic devices. Here, we review the physics and applications of techniques that utilize voltage to manipulate the interfacial tension of liquid metals; such techniques include electrocapillarity, continuous electrowetting, electrowetting-on-dielectric, and electrochemistry. These techniques lower the interfacial tension between liquid metals and a surrounding electrolyte by driving charged species (or in the case of electrochemistry, chemical species) to the interface. The techniques are useful for manipulating and actuating liquid metals at sub-mm length scales where interfacial forces dominate. We focus on metals and alloys that are liquid near or below room temperature (mercury, gallium, and gallium-based alloys). The review includes discussion of mercury—despite its toxicity—because it has been utilized in numerous applications and it offers a way of introducing several phenomena without the complications associated with the oxide layer that forms on gallium and its alloys. The review focuses on the advantages, applications, opportunities, challenges, and limitations of utilizing voltage to control interfacial tension as a method to manipulate liquid metals.

  20. Nuclear processes in deuterium/natural hydrogen-metal systems

    International Nuclear Information System (INIS)

    Zelensky, V.F.

    2013-01-01

    The survey presents the analysis of the phenomena taking place in deuterium - metal and natural hydrogen - metal systems under cold fusion experimental conditions. The cold fusion experiments have shown that the generation of heat and helium in the deuterium-metal system without emission of energetic gamma-quanta is the result of occurrence of a chain of chemical, physical and nuclear processes observed in the system, culminating in both the fusion of deuterium nuclei and the formation of a virtual, electron-modified excited 4He nucleus. The excitation energy of the helium nucleus is transferred to the matrix through emission of conversion electrons, and that, under appropriate conditions, provides a persistent synthesis of deuterium. The processes occurring in the deuterium/natural hydrogen - metal systems have come to be known as chemonuclear DD- and HD-fusion. The mechanism of stimulation of weak interaction reactions under chemonuclear deuterium fusion conditions by means of strong interaction reactions has been proposed. The results of numerous experiments discussed in the survey bear witness to the validity of chemonuclear fusion. From the facts discussed it is concluded that the chemonuclear deuterium fusion scenario as presented in this paper may serve as a basis for expansion of deeper research and development of this ecologically clean energy source. It is shown that the natural hydrogen-based system, containing 0.015% of deuterium, also has good prospects as an energy source. The chemonuclear fusion processes do not require going beyond the scope of traditional physics for their explanation

  1. Heat transfer on liquid-liquid interface of molten-metal and water

    International Nuclear Information System (INIS)

    Tanaka, T.; Saito, Yasushi; Mishima, Kaichiro

    2001-01-01

    Molten-core pool had been formed in the lower-head of TMI-2 pressure vessel at the severe accident. The lower head, however, didn't receive any damage by reactor core cooling. Heat transfer at outside of the lower head and boiling heat transfer at liquid-liquid interface of molten-metal and water, however, are important for initial cooling process of the molten-core pool. The heat transfer experiments for the liquid-liquid interface of molten-metal and water are carried out over the range of natural convection to film boiling region. Phenomenon on the heat transfer experiments are visualized by using of high speed video camera. Wood's metal and U-alloy 78 are used as molten-metal. The test section of the experiments consists of a copper block with heater, wood's metal, and water. Three thermocouple probes are used for temperature measurement of water side and the molten-metal side. Stability of the liquid-liquid interface is depended on the wetness of container wall for molten metal and the temperature distribution of the interface. Entrainment phenomena of molten-metal occurs by a fluctuation of the interface after boiling on the container wall surface. The boiling curves obtained from the liquid-liquid interface experiments are agree with the nucleate boiling and the film boiling correlations of solid-liquid system. (Suetake, M.)

  2. Catalytic activation of molecular hydrogen in alkyne hydrogenation reactions by lanthanide metal vapor reaction products

    International Nuclear Information System (INIS)

    Evans, W.J.; Bloom, I.; Engerer, S.C.

    1983-01-01

    A rotary metal vapor was used in the synthesis of Lu, Er, Nd, Sm, Yb, and La alkyne, diene, and phosphine complexes. A typical catalytic hydrogenation experiment is described. The lanthanide metal vapor product is dissolved in tetrahydrofuran or toluene and placed in a pressure reaction vessel 3-hexyne (or another substrate) is added, the chamber attached to a high vacuum line, cooled to -196 0 C, evacuated, warmed to ambient temperature and hydrogen is added. The solution is stirred magnetically while the pressure in monitored. The reaction products were analyzed by gas chromatography. Rates and products of various systems are listed. This preliminary survey indicates that catalytic reaction chemistry is available to these metals in a wide range of coordination environments. Attempts to characterize these compounds are hampered by their paramagnetic nature and their tendency to polymerize

  3. Exploring liquid metal plasma facing component (PFC) concepts-Liquid metal film flow behavior under fusion relevant magnetic fields

    International Nuclear Information System (INIS)

    Narula, M.; Abdou, M.A.; Ying, A.; Morley, N.B.; Ni, M.; Miraghaie, R.; Burris, J.

    2006-01-01

    The use of fast moving liquid metal streams or 'liquid walls' as a plasma contact surface is a very attractive option and has been looked upon with considerable interest over the past several years, both by the plasma physics and fusion engineering programs. Flowing liquid walls provide an ever replenishing contact surface to the plasma, leading to very effective particle pumping and surface heat flux removal. A key feasibility issue for flowing liquid metal plasma facing component (PFC) systems, pertains to their magnetohydrodynamic (MHD) behavior under the spatially varying magnetic field environment, typical of a fusion device. MHD forces hinder the development of a smooth and controllable liquid metal flow needed for PFC applications. The present study builds up on the ongoing research effort at UCLA, directed towards providing qualitative and quantitative data on liquid metal free surface flow behavior under fusion relevant magnetic fields

  4. Capillary Flow of Liquid Metals in Brazing

    Science.gov (United States)

    Dehsara, Mohammad

    Capillary flow is driven or controlled by capillary forces, exerted at the triple line where the fluid phases meet the solid boundary. Phase field (PF) models naturally accommodate diffusive triple line motion with variable contact angle, thus allowing for the no-slip boundary condition without the stress singularities. Moreover, they are uniquely suited for modeling of topological discontinuities which often arise during capillary flows. In this study, we consider diffusive triple line motion within two PF models: the compositionally compressible (CC) and the incompressible (IC) models. We derive the IC model as a systematic approximation to the CC model, based on a suitable choice of continuum velocity field. The CC model, applied to the fluids of dissimilar mass densities, exhibits a computational instability at the triple line. The IC model perfectly represents the analytic equilibria. We develop the parameter identification procedure and show that the triple line kinetics can be well represented by the IC model's diffusive boundary condition. The IC model is first tested by benchmarking the phase-field and experimental kinetics of water, and silicone oil spreading over the glass plates in which two systems do not interact with the substrate. Then, two high-temperature physical settings involving spreading of the molten Al-Si alloy: one over a rough wetting substrate, the other over a non-wetting substrate are modeled in a T-joint structure which is a typical geometric configuration for many brazing and soldering applications. Surface roughness directly influences the spreading of the molten metal by causing break-ups of the liquid film and trapping the liquid away from the joint. In the early stages of capillary flow over non-wetting surface, the melting and flow are concurrent, so that the kinetics of wetting is strongly affected by the variations in effective viscosity of the partially molten metal. We define adequate time-dependent functions for the

  5. Inducer pumps for liquid metal reactor plants

    International Nuclear Information System (INIS)

    Jackson, E.D.

    2002-01-01

    Pumps proposed for liquid metal reactor plants typically use centrifugal impellers as the rotating element and are required to maintain a relatively low speed to keep the suction specific speed low enough to operate at the available net positive suction head (HPSH) and to avoid cavitation damage. These low speeds of operation require that the pump diameter increase and/or multiple stages be used to achieve the design head. This frequently results in a large, heavy, complex pump design. In addition, the low speed results in a larger drive motor size so that the resultant penalty to the plant designer is multiplied. The heavier pump can also result in further complications as, e.g., the difficulty in maintaining the first critical speed sufficiently above the pump operating range to provide margin for rotor dynamic stability. To overcome some of these disadvantages, it was proposed the use of inducer pumps for Liquid Metal Fast Breeder Reactor (LMFBR) plants. This paper discusses some of the advantages of the inducer pump and the development history of designing and testing these pumps both in water and sodium. The inducer pump is seen to be a sound concept with a strong technology base derived from the aerospace and ship propulsion industries. The superior suction performance capability of the inducer offers significant system design advantages, primarily a smaller, lighter weight, less complex pump design with resulting saving in cost. Extensive testing of these pumps has been conducted in both sodium and water to demonstrate the long-life capability with no cavitation damage occurring in those designs based on Rockwell's current design criteria. These tests have utilized multiple inspection and measurement approaches to accurately assess and identify any potential for cavitation damage, and these approaches have all concluded that no damage is occurring. Therefore, it is concluded that inducer pumps can be safely designed for long life operation in sodium with

  6. Electrochemical reduction of metal ions in dilute solution using hydrogen

    NARCIS (Netherlands)

    Portegies Zwart, I.; Wijnbelt, E.C.W.; Janssen, L.J.J.

    1995-01-01

    Reduction of metal ions in dilute solutions is of great interest for purification of waste waters and process liquids. A new electrochemical cell has been introduced. This cell - a GBC-cell - is a combination of a gasdiffusion electrode in direct contact with a packed bed of carbon particles.

  7. Development of hydrogen oxidizing bacteria using hydrogen from radiolysis or metal corrosion

    International Nuclear Information System (INIS)

    Libert, M.F.; Sellier, R.; Marty, V.; Camaro, S.

    2000-01-01

    The effect of many parameters need to be studied to characterize the long term behavior of nuclear waste in a deep repository. These parameters concern the chemical effects, radiolytic effects, mechanical properties, water composition, and microbiological activity. To evaluate microbial activity in such an environment, work was focused on an inventory of key nutrients (C, H, 0, N, P, S) and energy sources required for bacterial growth. The production of hydrogen in the nuclear waste environment leads to the growth of hydrogen oxidizing bacteria, which modify the gas production balance. A deep repository containing bituminized waste drums implies several sources of hydrogen: - water radiolysis; -corrosion of metal containers; - radiolysis of the embedding matrix (bitumen). Two deep geological disposal conditions leading to H 2 production in a bituminized nuclear waste environment were simulated in the present study: - H 2 production by iron corrosion under anaerobic conditions was simulated by adding 10% of H 2 in the atmosphere; - H 2 production by radiolysis of bitumen matrix was approached by subjecting this material to external gamma irradiation with a dose rate near real conditions (6 Gy/h). The presence of dissolved H 2 in water allows the growth of hydrogen oxidizing bacteria leading to: - CO 2 and N 2 production; - H 2 consumption; - lower NO 3 - concentration caused by reduction to nitrogen. In the first case, hydrogen consumption is limited by the NO 3 - release rate from the bitumen matrix. In the second case, however, under gamma radiation at a low dose rate, hydrogen production is weak, and the hydrogen is completely consumed by microorganisms. Knowledge about these hydrogen oxidizing bacteria is just beginning to emerge. Heterotrophic denitrifying bacteria adapt well to hydrogen metabolism (autotrophic metabolism) by oxidizing H 2 instead of hydrocarbons. (authors)

  8. Thermal management of Li-ion battery with liquid metal

    International Nuclear Information System (INIS)

    Yang, Xiao-Hu; Tan, Si-Cong; Liu, Jing

    2016-01-01

    Highlights: • Liquid metal is used for power battery pack thermal management. • Better cooling performance and more uniform module temperature is obtained. • Less power consumption is needed. • The proposed liquid metal cooling system is robust and can cope with stressful conditions. - Abstract: Thermal management especially cooling of electric vehicles (EVs) battery pack is of great significance for guaranteeing the performance of the cells as well as safety and high-efficiency working of the EVs. Liquid cooling is a powerful way to keep the battery temperature in a proper range. However, the efficiency of conventional liquid cooling is still limited due to the inherently low thermal conductivity of the coolant which is usually water or aqueous ethanol. In this paper, a new kind of coolant, liquid metal, is proposed to be used for the thermal management of the battery pack. Mathematical analysis and numerical simulations are conducted to evaluate the cooling capability, pump power consumption and module temperature uniformity of the liquid metal cooling system, in comparison with that of water cooling. The results show that under the same flow conditions, a lower and more uniform module temperature can be obtained and less pump power consumption are needed in the liquid metal cooling system. In addition, liquid metal has an excellent cooling capability coping with stressful conditions, such as high power draw, defects in cells, and high ambient temperature. This makes it a promising coolant for the thermal management of high driving force EVs and quick charge batteries.

  9. Structural disorder in metallic glass-forming liquids.

    Science.gov (United States)

    Pan, Shao-Peng; Feng, Shi-Dong; Wang, Li-Min; Qiao, Jun-Wei; Niu, Xiao-Feng; Dong, Bang-Shao; Wang, Wei-Min; Qin, Jing-Yu

    2016-06-09

    We investigated structural disorder by a new structural parameter, quasi-nearest atom (QNA), in atomistic configurations of eight metallic glass-forming systems generated through molecular dynamics simulations at various temperatures. Structural analysis reveals that the scaled distribution of the number of QNA appears to be an universal property of metallic liquids and the spatial distribution of the number of QNA displays to be clearly heterogeneous. Furthermore, the new parameter can be directly correlated with potential energy and structural relaxation at the atomic level. Some straightforward relationships between QNA and other properties (per-atom potential energy and α-relaxation time) are introduced to reflect structure-property relationship in metallic liquids. We believe that the new structural parameter can well reflect structure disorder in metallic liquids and play an important role in understanding various properties in metallic liquids.

  10. Liquid metal cooling concepts in solar power application

    International Nuclear Information System (INIS)

    Deegan, P.B.; Mangus, J.D.; Whitlow, G.A.

    1978-01-01

    The thermodynamic and thermophysical properties and proven technology of a liquid sodium heat transport system provide numerous advantages and benefits for application in a central receiver solar thermal power plant concept. The major advantages of utilizing liquid sodium are: attainment of high thermodynamic cycle efficiencies, reduced relative costs, and achievement of these goals by the mid-1980's through the utilization of proven liquid metal technology developed in the power industry, without the need for extensive development programs. The utilization of liquid sodium reduces the complexity of the design of these systems, thus providing confidence in system reliability. The implementation of the proven technology in liquid metal systems also provides assurance of reliability. In addition, the ease of transition from liquid metal breeder reactor systems to solar application provides immediate availability of this technology

  11. Dynamic stabilization of imploding liquid metal liner

    International Nuclear Information System (INIS)

    Itoh, Yasuyuki; Fujiie, Yoichi

    1979-01-01

    The rotational stabilization has been proposed against the Rayleigh-Taylor instability of the imploding liquid metal liner. In this paper, the discussion is made on the possibility of the dynamic stabilization by applying the oscillating azimuthal magnetic field in addition to the axial field. In contrast to the rotational stabilization, the required (field) energy for this stabilization is also used for the liner driving or the plasma confinement. In the analysis, the liner subjected to the acceleration is assumed to be infinitely long, at rest and have the situation at the start of the implosion or turnaround. At turnaround, the existence of the plasma is taken into account. The perturbed motion of the liner is discussed with a linear stability analysis. Results are as follows: (1) The dynamic stabilization at the start of the implosion is possible if the distance from the conducting wall to the liner outer surface is comparable with or less than the liner thickness. (2) At turnaround, the stability is improved with decreasing the ratio of the plasma radius to that of the liner inner surface however the kink mode (m = 1) cannot be suppressed. (author)

  12. Liquid metal coolant flow rate regulation

    International Nuclear Information System (INIS)

    Vitkovskij, I.V.; Glukhikh, V.A.; Kirillov, I.R.; Smirnov, A.M.

    1981-01-01

    Some aspects of fast reactor and experimental bench operation related to liquid metal flow rate regulation are considered. Requirements to the devices for the flow rate regulation are formulated. A new type of these devices namely magnetohydrodynamic (MHD) throttles is described. Structural peculiarities of MHD throttles of different types are described as well. It is noted that the MHD throttles with a screw channel have the best energy mass indices. On the basis of the comparison of the MHD throttles with mechanical valves it is concluded that the MHD throttles described are useful for regulating the flow rates of any working media. Smoothness and accuracy of the flow rate regulation by the throttles are determined by the electric control circuit and may be practically anyone. The total coefficient of hydraulic losses in the throttle channel in the absence of a magnetic field is ten and more times lesser than in completely open mechanical valve. Electromagnetic time constant of the MHD throttles does not exceed several tenths of a second [ru

  13. Turbulent temperature fluctuations in liquid metals

    International Nuclear Information System (INIS)

    Lawn, C.J.

    1977-01-01

    Examination of experimental data for the spectral distribution of velocity (u and v) and temperature (theta) fluctuations in the fully turbulent region of heated pipe-flow has suggested a schematic representation which incorporates the essential features. Evidence is cited to suggest that the -vtheta correlation coefficient maintains higher values that the uv coefficient at wave-numbers in the inertial subrange. The theory of Batchelor, Howells and Townsend, and limited evidence from experiments in mercury, then suggests the form of the theta 2 spectra and -vtheta cross-spectra in liquid metals. From this information, a limiting Peclet number is deduced, above which the correlation coefficient of v and theta should be a fairly weak function of Pe alone. An attempt to check this inference from published data for the RMS level of temperature fluctuations, and for the turbulent Prandtl number, proves inconclusive, because many of the correlation coefficients so estimated have values greater than unity. It is concluded that all these results for theta tilde must therefore be in error. However, since there is no evidence of very low correlation coefficients, they almost certainly lie in the range 0.5 multiply/divide 2 over a large proportion of the radius. Thus theta tilde can be estimated for any fluid in which the fluctuations are induced by uniform heating, at least to within a factor of 2, using the analysis presented. (author)

  14. Thermomechanics of hydrogen storage in metallic hydrides: modeling and analysis

    Czech Academy of Sciences Publication Activity Database

    Roubíček, Tomáš; Tomassetti, G.

    2014-01-01

    Roč. 19, č. 7 (2014), s. 2313-2333 ISSN 1531-3492 R&D Projects: GA ČR GA201/09/0917 Institutional support: RVO:61388998 Keywords : metal-hydrid phase transformation * hydrogen diffusion * swelling Subject RIV: BA - General Mathematics Impact factor: 0.768, year: 2014 http://aimsciences.org/journals/pdfs.jsp?paperID=10195&mode=full

  15. Selective gettering of hydrogen in high pressure metal iodide lamps

    International Nuclear Information System (INIS)

    Kuus, G.

    1976-01-01

    One of the main problems in the manufacture of high pressure gas discharge lamps is the elimination of gaseous impurities from their arc tubes. Long degassing processes of all the lamp components are necessary in order to produce lamps with a low ignition voltage and good maintenance of the radiation properties. The investigation described deals with a selective getter place in the arc tube which can replace the long degassing process. The getter consists of a piece of yttrium encapsulated in thin tantalum foil. By this way it is possible to use the gettering action of tantalum and yttrium without having reaction between the metal iodide of the arc tube and yttrium. Yttrium is used because this metal can adsorb a large quantity of hydrogen even at a temperature of 1000 0 C. Hydrogen forms the main gaseous impurity in the high pressure metal iodide lamp. For this reason the adsorption properties like adsorption rate and capacity of the tantalum--yttrium getter for hydrogen are examined, and the results obtained from lamp experiments are given

  16. Diverse transformations of liquid metals between different morphologies.

    Science.gov (United States)

    Sheng, Lei; Zhang, Jie; Liu, Jing

    2014-09-10

    Transformation from a film into a sphere, rapid merging of separate objects, controlled self-rotation, and planar locomotion are the very unusual phenomena observed in liquid metals under application of an electric field to a liquid metal immersed in or sprayed with water. A mechanism for these effects is suggested and potential applications - for example the recovery of liquid metal previously injected into the body for therapeutic purposes - are outlined. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Magnetohydrodynamic instability of a cylindrical liquid-metal brush

    International Nuclear Information System (INIS)

    Hong, S.H.; Wilhelm, H.E.

    1976-01-01

    The stability of a homopolar generator brush, consisting of a liquid-metal-filled cavity between rotating (rotor) and fixed (stator) cylinder electrodes, is analyzed in the presence of radial current transport and an axial homogeneous magnetic field. Within the frame of linear magnetohydrodynamics, it is shown that the liquid-metal flow in the brush is always unstable if the brush transports current. In the absence of current flow (infinite load) the axial magnetic field stabilizes the liquid-metal flow in the brush if the magnetic energy density is larger than a certain fraction of the energy density of the rotating fluid

  18. Thermal behaviors of liquid La-based bulk metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, D. W.; Wang, X. D., E-mail: wangxd@zju.edu.cn, E-mail: jiangjz@zju.edu.cn; Lou, H. B.; Cao, Q. P.; Jiang, J. Z., E-mail: wangxd@zju.edu.cn, E-mail: jiangjz@zju.edu.cn [International Center for New-Structured Materials (ICNSM), Laboratory of New-Structured Materials, State Key Laboratory of Silicon Materials, and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Wang, L. W. [Institute of Materials Science and Engineering, Lanzhou University, Lanzhou 730000 (China); Zhang, D. X. [State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310027 (China)

    2014-12-14

    Thermal behaviors of liquid La-based bulk metallic glasses have been measured by using the dilatometer with a self-sealed sample cell. It is demonstrated that the strong glass forming liquid not only has the small thermal expansion coefficient but also shows the slow variation rate. Moreover, the strong glass former has relatively dense atomic packing and also small density change in the liquid state. The results suggest that the high glass forming ability of La-based metallic glasses would be closely related to the slow atomic rearrangements in liquid melts.

  19. Hydrogen production during processing of radioactive sludge containing noble metals

    International Nuclear Information System (INIS)

    Ha, B.C.; Ferrara, D.M.; Bibler, N.E.

    1992-01-01

    Hydrogen was produced when radioactive sludge from Savannah River Site radioactive waste containing noble metals was reacted with formic acid. This will occur in a process tank in the Defense Waste Facility at SRS when waste is vitrified. Radioactive sludges from four tanks were tested in a lab-scale apparatus. Maximum hydrogen generation rates varied from 5 x10 -7 g H 2 /hr/g of sludge from the least reactive sludge (from Waste Tank 51) to 2 x10 -4 g H 2 /hr/g of sludge from the most reactive sludge (from Waste Tank 11). The time required for the hydrogen generation to reach a maximum varied from 4.1 to 25 hours. In addition to hydrogen, carbon dioxide and nitrous oxide were produced and the pH of the reaction slurry increased. In all cases, the carbon dioxide and nitrous oxide were generated before the hydrogen. The results are in agreement with large-scale studies using simulated sludges

  20. Hydrogen storage by reaction between metallic amides and imides

    International Nuclear Information System (INIS)

    Eymery, J.B.; Cahen, S.; Tarascon, J.M.; Janot, R.

    2007-01-01

    This paper details the various metal-N-H systems reported in the literature as possible hydrogen storage materials. In a first part, we discuss the hydrogen storage performances of the Li-N-H system and the desorption mechanism of the LiH-LiNH 2 mixture is especially presented. The possibility of storing hydrogen using two other binary systems (Mg-N-H and Ca-N-H) is described in a second part. In the third part of the paper, we discuss about the performances of the highly promising Li-Mg-N-H system, for which a nice reversibility is obtained at 200 C with an experimental hydrogen capacity of about 5.0 wt.%. Other ternary systems, as Li-B-N-H and Li-Al-N-H, are presented in the last part of this review paper. We especially emphasize the performances obtained in our Laboratory at Amiens with a LiAl(NH 2 ) 4 -LiH mixture able to desorb around 6.0 wt.% of hydrogen at only 130 C. (authors)

  1. Separation of rate processes for isotopic exchange between hydrogen and liquid water in packed columns 10

    International Nuclear Information System (INIS)

    Butler, J.P.; Hartog, J. den; Goodale, J.W.; Rolston, J.H.

    1977-01-01

    Wetproofed platinum catalysts in packed columns promote isotopic exchange between counter-current streams of hydrogen saturated with water vapour and liquid water. The net rate of deuterium transfer from isotopically enriched hydrogen has been measured and separated into two rate processes involving the transfer of deuterium from hydrogen to water vapour and from water vapour to liquid. These are compared with independent measurements of the two rate processes to test the two-step successive exchange model for trickle bed reactors. The separated transfer rates are independent of bed height and characterize the deuterium concentrations of each stream along the length of the bed. The dependences of the transfer rates upon hydrogen and liquid flow, hydrogen pressure, platinum loading and the effect of dilution of the hydrophobic catalyst with inert hydrophilic packing are reported. The results indicate a third process may be important in the transfer of deuterium between hydrogen and liquid water. (author)

  2. Two-dimensional thermal analysis of liquid hydrogen tank insulation

    Energy Technology Data Exchange (ETDEWEB)

    Babac, Gulru; Sisman, Altug [Istanbul Technical University, Energy Institute, Ayazaga campus, 34469 Maslak, Istanbul (Turkey); Cimen, Tolga [Jaguar and Landrover, Banbury Road, Gaydon, Warwick CV35 0RR (United Kingdom)

    2009-08-15

    Liquid hydrogen (LH{sub 2}) storage has the advantage of high volumetric energy density, while boil-off losses constitute a major disadvantage. To minimize the losses, complicated insulation techniques are necessary. In general, Multi Layer Insulation (MLI) and a Vapor-Cooled Shield (VCS) are used together in LH{sub 2} tanks. In the design of an LH{sub 2} tank with VCS, the main goal is to find the optimum location for the VCS in order to minimize heat leakage. In this study, a 2D thermal model is developed by considering the temperature dependencies of the thermal conductivity and heat capacity of hydrogen gas. The developed model is used to analyze the effects of model considerations on heat leakage predictions. Furthermore, heat leakage in insulation of LH{sub 2} tanks with single and double VCS is analyzed for an automobile application, and the optimum locations of the VCS for minimization of heat leakage are determined for both cases. (author)

  3. Hydrogen storage and evolution catalysed by metal hydride complexes.

    Science.gov (United States)

    Fukuzumi, Shunichi; Suenobu, Tomoyoshi

    2013-01-07

    The storage and evolution of hydrogen are catalysed by appropriate metal hydride complexes. Hydrogenation of carbon dioxide by hydrogen is catalysed by a [C,N] cyclometalated organoiridium complex, [Ir(III)(Cp*)(4-(1H-pyrazol-1-yl-κN(2))benzoic acid-κC(3))(OH(2))](2)SO(4) [Ir-OH(2)](2)SO(4), under atmospheric pressure of H(2) and CO(2) in weakly basic water (pH 7.5) at room temperature. The reverse reaction, i.e., hydrogen evolution from formate, is also catalysed by [Ir-OH(2)](+) in acidic water (pH 2.8) at room temperature. Thus, interconversion between hydrogen and formic acid in water at ambient temperature and pressure has been achieved by using [Ir-OH(2)](+) as an efficient catalyst in both directions depending on pH. The Ir complex [Ir-OH(2)](+) also catalyses regioselective hydrogenation of the oxidised form of β-nicotinamide adenine dinucleotide (NAD(+)) to produce the 1,4-reduced form (NADH) under atmospheric pressure of H(2) at room temperature in weakly basic water. In weakly acidic water, the complex [Ir-OH(2)](+) also catalyses the reverse reaction, i.e., hydrogen evolution from NADH to produce NAD(+) at room temperature. Thus, interconversion between NADH (and H(+)) and NAD(+) (and H(2)) has also been achieved by using [Ir-OH(2)](+) as an efficient catalyst and by changing pH. The iridium hydride complex formed by the reduction of [Ir-OH(2)](+) by H(2) and NADH is responsible for the hydrogen evolution. Photoirradiation (λ > 330 nm) of an aqueous solution of the Ir-hydride complex produced by the reduction of [Ir-OH(2)](+) with alcohols resulted in the quantitative conversion to a unique [C,C] cyclometalated Ir-hydride complex, which can catalyse hydrogen evolution from alcohols in a basic aqueous solution (pH 11.9). The catalytic mechanisms of the hydrogen storage and evolution are discussed by focusing on the reactivity of Ir-hydride complexes.

  4. Predicted energy densitites for nickel-hydrogen and silver-hydrogen cells embodying metallic hydrides for hydrogen storage

    Science.gov (United States)

    Easter, R. W.

    1974-01-01

    Simplified design concepts were used to estimate gravimetric and volumetric energy densities for metal hydrogen battery cells for assessing the characteristics of cells containing metal hydrides as compared to gaseous storage cells, and for comparing nickel cathode and silver cathode systems. The silver cathode was found to yield superior energy densities in all cases considered. The inclusion of hydride forming materials yields cells with very high volumetric energy densities that also retain gravimetric energy densities nearly as high as those of gaseous storage cells.

  5. Experimental studies on cold fusion and hydrogen-metal

    International Nuclear Information System (INIS)

    Locou, P.

    2007-01-01

    The cold fusion is a nuclear fusion realized in pervading conditions of temperature and pressure. My own process is parallel to that of the team of the University of Los Angeles, but shaped in 1996 within my personal and private Laboratory: A small cylinder in which we replace the air by some deuterium to the gas state in - 33 d egree (the deuterium is some hydrogen with a neutron, which we find in quantity in the sea water). We introduce a crystal there, extremely rare - the property of which is to emit continuously one thousand times dose of successful energy and it during several years without outside pyro, natural excitement - electric - that is it creates an electric field in the slightest change in temperature. We carry then the whole in + 7 d egree, what generates in some seconds a 200 000 volt electric field, an intense enough field to separate the pits of the deuterium of their electrons and to admit them to collide with those of the crystal. There is a fusion of protons between them (positive particles of the pit (core)) and a emission of neutrons, which do not merge. It is this emission which serves for measuring the quantity of energy produced by the fusion (merger). We so managed to produce some energy in unlimited quantity, allowing us to feed our installation with electric current in total autarky, and to reduce so our costs of functioning to divers domains. This crystal is exceptional in its applications and to give it the name would return has to break our current headway: the thorough problem, in this current period of takeover by the financial bodies of the possible patents, brought to us to the biggest caution as regards our results. And, as we look for no outside financing, we do not need to submit ourselves to the requirements lauded by the scientific Community, only our results are strictly estimated. For example we can make estimate our bars or patches of Hydrogen - Metal: a simple spectroscopy in YEW will give as result, only, the element H

  6. Highly stable noble-metal nanoparticles in tetraalkylphosphonium ionic liquids for in situ catalysis.

    Science.gov (United States)

    Banerjee, Abhinandan; Theron, Robin; Scott, Robert W J

    2012-01-09

    Gold and palladium nanoparticles were prepared by lithium borohydride reduction of the metal salt precursors in tetraalkylphosphonium halide ionic liquids in the absence of any organic solvents or external nanoparticle stabilizers. These colloidal suspensions remained stable and showed no nanoparticle agglomeration over many months. A combination of electrostatic interactions between the coordinatively unsaturated metal nanoparticle surface and the ionic-liquid anions, bolstered by steric protection offered by the bulky alkylated phosphonium cations, is likely to be the reason behind such stabilization. The halide anion strongly absorbs to the nanoparticle surface, leading to exceptional nanoparticle stability in halide ionic liquids; other tetraalkylphosphonium ionic liquids with non-coordinating anions, such as tosylate and hexafluorophosphate, show considerably lower affinities towards the stabilization of nanoparticles. Palladium nanoparticles stabilized in the tetraalkylphosphonium halide ionic liquid were stable, efficient, and recyclable catalysts for a variety of hydrogenation reactions at ambient pressures with sustained activity. Aerial oxidation of the metal nanoparticles occurred over time and was readily reversed by re-reduction of oxidized metal salts. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Infrared Spectroscopy as Molecular Probe of the Macroscopic Metal-Liquid Interface

    Directory of Open Access Journals (Sweden)

    Johannes Kiefer

    2017-11-01

    Full Text Available Metal-liquid interfaces are of the utmost importance in a number of scientific areas, including electrochemistry and catalysis. However, complicated analytical methods and sample preparation are usually required to study the interfacial phenomena. We propose an infrared spectroscopic approach that enables investigating the molecular interactions at the interface, but needing only minimal or no sample preparation. For this purpose, the internal reflection element (IRE is wetted with a solution as first step. Second, a small plate of the metal of interest is put on top and pressed onto the IRE. The tiny amount of liquid that is remaining between the IRE and the metal is sufficient to produce an IR spectrum with good signal to noise ratio, from which information about molecular interactions, such as hydrogen bonding, can be deduced. Proof-of-concept experiments were carried out with aqueous salt and acid solutions and an aluminum plate.

  8. Experiments on the thermalization of slow neutrons by liquid hydrogen (1962); Experience de thermalisation de neutrons lents par de l'hydrogene liquide (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Cribier, D; Jacrot, B; Lacaze, A; Roubeau, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Institut Fourier, 38 - Grenoble (France)

    1962-07-01

    In order to increase the flux of neutrons of long wave-length ({lambda} > 4 A) emerging from a channel in the EL-3, a liquid hydrogen device was introduced into a channel of the reactor (Channel H{sub 1}). The principle of the device is simple. A volume of liquid hydrogen is introduced as close as possible to the reactor core into a region of intense isotropic flux. This hydrogen slows down the slow neutrons; because of the very small mean free diffusion path of slow in hydrogen, this slowing down is considerable even in a small volume of liquid hydrogen, and the spectrum temperature of neutrons emerging from the volume of liquid hydrogen can therefore be shifted. The intensity gain for neutrons with a wave length {lambda}, is a G ({lambda}) function which, for perfect thermalization and ignoring capture, is expressed by: G ({lambda}) = 225 exp (- 45.3/{lambda}{sup 2}), assuming a temperature of 300 deg. K for the neutrons before cooling and is 20 deg. K after cooling. For a wave-length of 5 A, the theoretical maximum gain of thus about 37. (authors) [French] Dans le but d'accroitre le flux des neutrons de grande longueur d'onde ({lambda} > 4 A) sortant d'un canal de la pile EL-3, un dispositif a hydrogene liquide a ete introduit dans un canal de la pile (canal H{sub 1}). Le principe du dispositif est simple. Un volume d'hydrogene liquide est introduit le plus pres possible du coeur de ia pile dans une region de flux intense et isotrope. Les neutrons lents sont ralentis par cet hydrogene; a cause du tres faible libre parcours moyen de diffusion des neutrons lents dans l'hydrogene, ce ralentissement est important meme dans un faible volume d'hydrogene liquide et l'on peut ainsi deplacer la temperature du spectre des neutrons sortant du volume d'hydrogene liquide. Le gain en intensite des neutrons de longueur d'onde {lambda} est une fonction G ({lambda}) qui pour une thermalisation parfaite et en negligeant la capture, s'exprime par: G ({lambda}) = 225 exp (- 45

  9. Metal and hydrogen catalysis in isotopic hydrogen exchange in some biologically important heterocyclic compounds

    International Nuclear Information System (INIS)

    Buncel, E.; Joly, H.A.; Jones, J.R.; Onyido, I.

    1989-01-01

    This study reports on the catalytic roles of metal and hydrogen ions in tritium exchange in some heterocyclic substrates which occur as residues in many biologically important molecules. We have found that detritiation of 1-methyl[2- 3 H]imidazole is inhibited by a number of metal ions. As well, inhibition of exchange rates was noted with Ag(I) and Cu(II) for [2- 3 H]thiazole and 1-methyl[8- 3 H]inosine, with Ag(I) for [2- 3 H]benzothiazole, and with Cu(II) for 1-methyl[8- 3 H]guanosine. A complete mechanistic description, which includes the various metal ion-coordinated species generated under the experimental conditions, is presented. The results demonstrate the reactivity order: protonated >> metal-coordinated >> neutral substrates. The differential catalytic effects of metal and hydrogen ions in these processes are discussed in terms of the extent of charge developed on the ligating heteroatom in the reaction intermediate. (author). 13 refs.; 1 fig

  10. Vapour pressure isotope effects in liquid hydrogen chloride

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, J.N.C.; Calado, J.C.G. (Instituto Superior Tecnico, Lisbon (Portugal)); Jancso, Gabor (Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics)

    1992-08-10

    The difference between the vapour pressures of HCl and DCl has been measured over the temperature range 170-203 K by a differential manometric technique in a precision cryostat. In this range the vapour pressure of HCl is higher than that of DCl by 3.2% at 170 K, decreasing to 0.9% at 200 K. The reduced partition function ratios f[sub l]/f[sub g] derived from the vapour pressure data can be described by the equation ln(f[sub l]/f[sub g]) = (3914.57[+-]10)/T[sup 2] - (17.730[+-]0.055)/T. The experimentally observed H-D vapour pressure isotope effect, together with the values on the [sup 35]Cl-[sup 37]Cl isotope effect available in the literature, is interpreted in the light of the statistical theory of isotope effects in condensed systems by using spectroscopic data of the vapour and liquid phases. The results indicate that the rotation in liquid hydrogen chloride is hindered. Temperature-dependent force constants for the hindered translational and rotational motions were invoked in order to obtain better agreement between the model calculation and experiment. (author).

  11. Annular Air Leaks in a liquid hydrogen storage tank

    Science.gov (United States)

    Krenn, AG; Youngquist, RC; Starr, SO

    2017-12-01

    Large liquid hydrogen (LH2) storage tanks are vital infrastructure for NASA, the DOD, and industrial users. Over time, air may leak into the evacuated, perlite filled annular region of these tanks. Once inside, the extremely low temperatures will cause most of the air to freeze. If a significant mass of air is allowed to accumulate, severe damage can result from nominal draining operations. Collection of liquid air on the outer shell may chill it below its ductility range, resulting in fracture. Testing and analysis to quantify the thermal conductivity of perlite that has nitrogen frozen into its interstitial spaces and to determine the void fraction of frozen nitrogen within a perlite/frozen nitrogen mixture is presented. General equations to evaluate methods for removing frozen air, while avoiding fracture, are developed. A hypothetical leak is imposed on an existing tank geometry and a full analysis of that leak is detailed. This analysis includes a thermal model of the tank and a time-to-failure calculation. Approaches to safely remove the frozen air are analyzed, leading to the conclusion that the most feasible approach is to allow the frozen air to melt and to use a water stream to prevent the outer shell from chilling.

  12. Static phenomena at the charged surface of liquid hydrogen

    International Nuclear Information System (INIS)

    Levchenko, A.A.; Kolmakov, G.V.; Mezhov-Deglin, L.P.; Mikhjlov, M.G.; Trusov, A.B.

    1999-01-01

    The shape evolution of the equipotentially charged surface of liquid hydrogen layer covering the lower plate of a horizontally arranged diode in external electric fields has been studied experimentally for the first time. A reconstruction phenomenon (the formation of a stationary hump) at the flat charged surface at voltages higher than a certain critical U c1 was observed under the conditions of total compensation of the electric field in the bulk liquid by a surface charge. It is shown that the transition of the flat charged surface into the reconstructed state is a phase transition closed to the second order phase transition. The height of the hump increased with increasing the voltage and at U c2 > 1,2 U c1 the reconstructed surface lost the stability, and a stream discharge pulse was observed. The shape evolution of a changed droplet of constant volume suspended at the upper plate of the diode when the stretching electric field and gravity forces act in the same direction was studied as the voltage was increased up to the discharge

  13. Characterization of liquid metal reactor materials

    International Nuclear Information System (INIS)

    Kuk, I. H.; Ryu, W. S.; Kim, H. H. and others

    1999-03-01

    The objectives of this report were to assess the material requirements for LMR environment, to select the optimum candidates for KALIMER components, to characterize the performance for establishing a database of the structural materials for KALIMER, and to develop the basic material technologies for the localization of the advanced materials. Stainless steel ingots were melted by VIM and hot-rolled to plate with the thickness of 15mm. The plate was solution-treated for 1 hr at 1100 deg C and then water-quenched. Specimens were taken parallel to the rolling direction of the plate. The effects of nitrogen and phosphorus were analyzed on the high temperature mechanical properties of 316MRP (Liquid Metal Reactor, Primary candidate material) stainless steels with the different nitrogen content from 0.04 to 0.15% and with the different phosphorus content from 0.002 to 0.02%. Heat treatment was performed to investigate the changes in microstructure and mechanical properties of Cr-Mo steels for LMR heat transfer tube materials and core materials. The Cr-Mo steels were normalized at the temperatures between 900 deg C and 1200 deg C for 1hrs and tempered at the temperatures between 500 deg C and 800 deg C for 2hrs. Conventional optical and electron micrographic studies were carried out to investigate the martensite lath structure, carbide indentification and carbide shape. Vickers microhardness was measured at room temperature using 10g load. Tensile properties were tested at high temperature. Charpy V-notch impact tests were also carried out at temperature between -120 deg C and +180 deg C. (author). 72 refs., 28 tabs., 244 figs

  14. Turbulent convection in liquid metal with and without rotation.

    Science.gov (United States)

    King, Eric M; Aurnou, Jonathan M

    2013-04-23

    The magnetic fields of Earth and other planets are generated by turbulent, rotating convection in liquid metal. Liquid metals are peculiar in that they diffuse heat more readily than momentum, quantified by their small Prandtl numbers, Pr rotating Rayleigh-Bénard convection experiments in the liquid metal gallium (Pr = 0.025) over a range of nondimensional buoyancy forcing (Ra) and rotation periods (E). Our primary diagnostic is the efficiency of convective heat transfer (Nu). In general, we find that the convective behavior of liquid metal differs substantially from that of moderate Pr fluids, such as water. In particular, a transition between rotationally constrained and weakly rotating turbulent states is identified, and this transition differs substantially from that observed in moderate Pr fluids. This difference, we hypothesize, may explain the different classes of magnetic fields observed on the Gas and Ice Giant planets, whose dynamo regions consist of Pr 1 fluids, respectively.

  15. Generation of core–shell nanoparticles Al@Ti by laser ablation in liquid for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Serkov, A.A. [Wave Research Center of A.M. Prokhorov General Physics Institute of the Russian Academy of Sciences, 38, Vavilov street, 119991 Moscow (Russian Federation); The Federal State Educational Institution of Higher Professional Education, “Moscow Institute of Physics and Technology (State University)”, 9, Institutsky lane, 141700, Dolgoprudny, Moscow (Russian Federation); Barmina, E.V.; Simakin, A.V. [Wave Research Center of A.M. Prokhorov General Physics Institute of the Russian Academy of Sciences, 38, Vavilov street, 119991 Moscow (Russian Federation); Kuzmin, P.G., E-mail: qzzzma@gmail.com [Wave Research Center of A.M. Prokhorov General Physics Institute of the Russian Academy of Sciences, 38, Vavilov street, 119991 Moscow (Russian Federation); Voronov, V.V. [A.M. Prokhorov General Physics Institute of the Russian Academy of Sciences, 38, Vavilov street, 119991 Moscow (Russian Federation); Shafeev, G.A. [Wave Research Center of A.M. Prokhorov General Physics Institute of the Russian Academy of Sciences, 38, Vavilov street, 119991 Moscow (Russian Federation); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 31, Kashirskoye highway, 115409 Moscow (Russian Federation)

    2015-09-01

    Highlights: • Core–shell Al@Ti NPs are generated by laser ablation in isopropanol. • Isopropanol was saturated with molecular hydrogen. • The composite metallic Al-Ti target was used. • HR TEM characterization shows that Ti core is covered by epitaxial Al shell. • Al@Ti NPs are promising for hydrogen storage. - Abstract: Core–shell Al@Ti nanoparticles are generated by ablation of a composite Ti–Al target in liquid isopropanol saturated with molecular hydrogen using a Nd:YAG laser with pulse duration of 10 ps and repetition rate of 200 kHz. The target is made of two plates of corresponding metals stacked together and placed into a flowing cell reactor. Transmission Electron Microscopy analysis of generated NPs reveals their core–shell structure with Ti core and Al shell. Average size of NPs determined by means of measuring disk centrifuge is around 40 nm. Saturation of NPs by hydrogen is due to sharp dependence of its solubility in these metals on temperature. XRD studies of generated NPs show the peaks of both metallic Ti and Al with some amount of TiO{sub 2}. No peaks of Ti–Al alloys are observed.

  16. Blanket of a hybrid thermonuclear reactor with liquid- metal cooling

    International Nuclear Information System (INIS)

    Terent'ev, I.K.; Fedorovich, E.P.; Paramonov, P.M.; Zhokhov, K.A.

    1982-01-01

    Blanket design of a hybrid thermopuclear reactor with a liquid metal coolant is described. To decrease MHD-resistance for uranium zone fuel elements a cylindrical shape is suggested and movement of liquid-metal coolant in fuel element packets is presumed to be in perpendicular to the magnetic field and fuel element axes direction. The first wall is cooled by water, blanket-by lithium-lead alloy

  17. Advancing liquid metal reactor technology with nitride fuels

    International Nuclear Information System (INIS)

    Lyon, W.F.; Baker, R.B.; Leggett, R.D.; Matthews, R.B.

    1991-08-01

    A review of the use of nitride fuels in liquid metal fast reactors is presented. Past studies indicate that both uranium nitride and uranium/plutonium nitride possess characteristics that may offer enhanced performance, particularly in the area of passive safety. To further quantify these effects, the analysis of a mixed-nitride fuel system utilizing the geometry and power level of the US Advanced Liquid Metal Reactor as a reference is described. 18 refs., 2 figs., 2 tabs

  18. A three-cell liquid hydrogen target for an extended focal plane polarimeter

    International Nuclear Information System (INIS)

    Golovanov, L.B.; Borzounov, Yu.T.; Piskunov, N.M.; Tsvinev, A.P.

    1996-01-01

    This article describes the design and working principle of a 3-cell liquid hydrogen target produced for the high-energy deuteron polarimeter HYPOM. This target uses liquid Helium as a cooling agent. After a general description of the apparatus, tests and operating modes are thoroughly explained. In particular the air controlled self regulation of Helium flow in the cryostat to stabilize the liquid hydrogen level is presented. (author)

  19. Alloying of Yb-Cu and Yb-Ag utilizing liquid ammonia metal solutions of ytterbium

    International Nuclear Information System (INIS)

    Imamura, H.; Yoshimura, T.; Sakata, Y.

    2003-01-01

    In the course of the studies on preparation of novel compounds using the dissolution of Eu or Yb metals in liquid ammonia, the formation of Yb-Cu and Yb-Ag intermetallic films has been found. When Cu or Ag metal powders were placed in a reactor containing a solution of Yb metal in liquid ammonia, the dissolved Yb readily react with the Cu or Ag metal particles to form surface alloy compounds. X-ray diffraction of Yb-Cu showed that upon thermal treatment above 673 K, the Yb metal deposited on the Cu particles reacted together to be transformed into the YbCu 6.5 intermetallic compound. A characteristic endothermic peak at 749 K, due to alloying of Yb-Cu, was observed by the differential scanning calorimeter measurements. By use of the high reactivity of liquid ammonia metal solutions of ytterbium, it was found that the ytterbium intermetallic films were readily formed under mild conditions. Yb-Cu and Yb-Ag exhibited enhanced catalytic activity for the hydrogenation of ethene as a result of alloying

  20. Metal-hydrogen systems with an exceptionally large and tunable thermodynamic destabilization

    NARCIS (Netherlands)

    Ngene, Peter; Longo, Alessandro; Mooij, L.P.A.; Bras, Wim; Dam, B.

    2017-01-01

    Hydrogen is a key element in the energy transition. Hydrogen-metal systems have been studied for various energy-related applications, e.g., for their use in reversible hydrogen storage, catalysis, hydrogen sensing, and rechargeable batteries. These applications depend strongly on the

  1. Hydrogen storage material and process using graphite additive with metal-doped complex hydrides

    Science.gov (United States)

    Zidan, Ragaiy [Aiken, SC; Ritter, James A [Lexington, SC; Ebner, Armin D [Lexington, SC; Wang, Jun [Columbia, SC; Holland, Charles E [Cayce, SC

    2008-06-10

    A hydrogen storage material having improved hydrogen absorbtion and desorption kinetics is provided by adding graphite to a complex hydride such as a metal-doped alanate, i.e., NaAlH.sub.4. The incorporation of graphite into the complex hydride significantly enhances the rate of hydrogen absorbtion and desorption and lowers the desorption temperature needed to release stored hydrogen.

  2. Alternative route to metal halide free ionic liquids

    International Nuclear Information System (INIS)

    Takao, Koichiro; Ikeda, Yasuhisa

    2008-01-01

    An alternative synthetic route to metal halide free ionic liquids using trialkyloxonium salt is proposed. Utility of this synthetic route has been demonstrated by preparing 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid through the reaction between 1-methylimidazole and triethyloxonium tetra-fluoroborate in anhydrous ether. (author)

  3. Controlled delamination of metal films by hydrogen loading

    Energy Technology Data Exchange (ETDEWEB)

    Nikitin, Eugen

    2008-11-18

    n this work we quantitatively determine the adhesion energy between metal films and their substrates. Therefore a new controlled buckling technique is established, applying the strong compressive in-plane stress that results in thin films clamped on rigid substrates during hydrogen loading. When the elastic energy stored in the H-loaded thin film exceeds the adhesion energy between film and substrate, delamination occurs. At the onset of delamination, a critical hydrogen concentration, a critical stress value and a critical bending of the substrate are present, which are quantitative measures for the adhesion energy and permit its calculation. As the critical values are determined at the onset of delamination, plastic deformation is negligible, which denies the quantitative determination of adhesion energies in conventional test setups. In multilayer-systems, adhesion energies between substrates and films that hardly absorb hydrogen can be measured by the controlled buckling technique, when the films of interest are coated with hydrogen absorbing films (active layer). The measurements are performed easily and can be repeated under the same test conditions, while variables such as the thickness of the coating materials or the boundary surface structure can be varied and optimized. In this work the adhesion energies of different materials on polycarbonate and niobium on sapphire are investigated. (orig.)

  4. Ternary Amides Containing Transition Metals for Hydrogen Storage: A Case Study with Alkali Metal Amidozincates.

    Science.gov (United States)

    Cao, Hujun; Richter, Theresia M M; Pistidda, Claudio; Chaudhary, Anna-Lisa; Santoru, Antonio; Gizer, Gökhan; Niewa, Rainer; Chen, Ping; Klassen, Thomas; Dornheim, Martin

    2015-11-01

    The alkali metal amidozincates Li4 [Zn(NH2)4](NH2)2 and K2[Zn(NH2)4] were, to the best of our knowledge, studied for the first time as hydrogen storage media. Compared with the LiNH2-2 LiH system, both Li4 [Zn(NH2)4](NH2)2-12 LiH and K2[Zn(NH2)4]-8 LiH systems showed improved rehydrogenation performance, especially K2[Zn(NH2)4]-8 LiH, which can be fully hydrogenated within 30 s at approximately 230 °C. The absorption properties are stable upon cycling. This work shows that ternary amides containing transition metals have great potential as hydrogen storage materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Chemistry and physics at liquid alkali metal/solid metal interfaces

    International Nuclear Information System (INIS)

    Barker, M.G.

    1977-01-01

    This paper describes the chemistry of processes which take place at the interface between liquid alkali metals and solid metal surfaces. A brief review of wetting data for liquid sodium is given and the significance of critical wetting temperatures discussed on the basis of an oxide-film reduction mechanism. The reactions of metal oxides with liquid metals are outlined and a correlation with wetting data established. The transfer of dissolved species from the liquid metal across the interface to form solid phases on the solid metal surface is well recognised. The principal features of such processes are described and a simple thermodynamic explanation is outlined. The reverse process, the removal of solid material into solution, is also considered. (author)

  6. Some aspects of hydrogen interaction with amorphous metallic materials

    International Nuclear Information System (INIS)

    Spivak, L.V.; Khonik, V.A.; Skryabina, N.E.

    1995-01-01

    For the first time is considered change of some properties of amorphous metallic materials (AMM) directly in the process of hydrogenation. A supposition is made that many found effects are consequence of accumulation and relief of internal stresses during hydrogenation, exposure or following annealing of AMM. Fe 81 B 14 Si 15 , Fe 52 Co 20 Si 15 B 13 , Fe 5 Co 70 Si 15 B 10 , Fe 5 Co 58 Ni 10 Si 11 B 16 , Co 67 Fe 4 Cr 7 Si 8 B 14 84KChSP, Ni 60 Nb 35 Ti 5 , Ni 60 Nb 40 and Pd 17,5 Cu 6 Si 16.5 AMM were investigated. 24 refs.; 4 figs

  7. Metal hydride hydrogen compression: recent advances and future prospects

    Science.gov (United States)

    Yartys, Volodymyr A.; Lototskyy, Mykhaylo; Linkov, Vladimir; Grant, David; Stuart, Alastair; Eriksen, Jon; Denys, Roman; Bowman, Robert C.

    2016-04-01

    Metal hydride (MH) thermal sorption compression is one of the more important applications of the MHs. The present paper reviews recent advances in the field based on the analysis of the fundamental principles of this technology. The performances when boosting hydrogen pressure, along with two- and three-step compression units, are analyzed. The paper includes also a theoretical modelling of a two-stage compressor aimed at describing the performance of the experimentally studied systems, their optimization and design of more advanced MH compressors. Business developments in the field are reviewed for the Norwegian company HYSTORSYS AS and the South African Institute for Advanced Materials Chemistry. Finally, future prospects are outlined presenting the role of the MH compression in the overall development of the hydrogen-driven energy systems. The work is based on the analysis of the development of the technology in Europe, USA and South Africa.

  8. Laser-induced separation of hydrogen isotopes in the liquid phase

    International Nuclear Information System (INIS)

    Beattie, W.; Freund, S.; Holland, R.; Maier, W.

    1980-01-01

    A process for separating hydrogen isotopes which comprises (A) forming a liquid phase of hydrogen-bearing feedstock compound at a temperature at which the spectral features of the feedstock compound are narrow enough or the absorption edges sharp enough to permit spectral features corresponding to the different hydrogen isotopes to be separated to be distinguished, (B) irradiating the liquid phase at said temperature with monochromatic radiation of a first wavelength which selectively or at least preferentially excites those molecules of said feedstock compound containing a first hydrogen isotope, and (C) subjecting the excited molecules to physical or chemical processes or a combination thereof whereby said first hydrogen isotope contained in said excited molecules is separated from other hydrogen isotopes contained in the unexcited molecules in said liquid phase

  9. Thermal expansion of metals over the entire liquid range

    International Nuclear Information System (INIS)

    Shaner, J.W.

    1977-01-01

    This paper reviews the current state of the art for measuring liquid metal densities. Conventional high precision techniques for use below 2000K as well as new techniques for more extreme temperatures are addressed. Pertinent data, which have appeared since the last critical reviews, for elemental metals are discussed

  10. Acoustical study of electro- and thermal conductivity of liquid metals

    International Nuclear Information System (INIS)

    Tekuchev, V.V.; Rygalov, L.N.; Ivanova, I.V.; Barashkov, B.I.

    2003-01-01

    One established a link between electrical, elastic and structural properties of electronic smelts. One calculated polyterms of resistance and thermal conductivity of liquid metals (Be, Cd, U, V, Mo, Cr, rare-earth metals) on the basis of data covering both melting and boiling points. For some metals the values were obtained for the first time. To analyze kinetic properties of metals under high temperatures one should apply complex many-particles model representations and efficient computing equipment. It is pointed out that essential problems blocking efforts to tackle the mentioned task result in necessity to find simple though approximate models describing satisfactorily properties of metals [ru

  11. Liquid metal cooled fast breeder nuclear reactors

    International Nuclear Information System (INIS)

    Barnes, S.

    1976-01-01

    Reference is made to liquid metal cooled fast breeder reactors of the 'pool' kind. In this type of reactor the irradiated fuel is lowered into a transfer rotor for removal to storage facilities, this rotor normally having provision for the temporary storage of 20 irradiated fuel assemblies, each within a stainless steel bucket. For insertion or withdrawal of a fuel assembly the rotor is rotated to bring the fuel assembly to a loading or discharging station. The irradiated fuel assembly is withdrawn from the rotor within its bucket and the total weight is approximately 1000 kg, which is lifted about 27 m. In the event of malfunction the combination falls back into the rotor with considerable force. In order to prevent damage to the rotor fracture pins are provided, and to prevent damage to the reactor vessel and other parts of the reactor structure deformable energy absorbing devices are provided. After a malfunction the fractured pins and the energy absorbing devices must be replaced by remote control means operated from outside the reactor vault - a complex operation. The object of the arrangement described is to provide improved energy absorbing means for fuel assemblies falling into a fuel transfer rotor. The fuel assemblies are supported in the rotor by elastic means during transfer to storage and a hydraulic dash pot is provided in at least one position below the rotor for absorbing the energy of a falling fuel assembly. It is preferable to provide dash pots immediately below a receiving station for irradiated fuel assemblies and immediately below a discharge station. Each bucket is carried in a container that is elastically supported in the transfer rotor on a helical coil compression spring, so that, in the event of a malfunction the container and bucket are returned to their normal operating position after the force of the falling load has been absorbed by the dash pot. The transfer rotor may also be provided with recoil springs to absorb the recoil energy

  12. SOLUBILITY OF IRON IN METALLIC HYDROGEN AND STABILITY OF DENSE CORES IN GIANT PLANETS

    International Nuclear Information System (INIS)

    Wahl, Sean M.; Wilson, Hugh F.; Militzer, Burkhard

    2013-01-01

    The formation of the giant planets in our solar system, and likely a majority of giant exoplanets, is most commonly explained by the accretion of nebular hydrogen and helium onto a large core of terrestrial-like composition. The fate of this core has important consequences for the evolution of the interior structure of the planet. It has recently been shown that H 2 O, MgO, and SiO 2 dissolve in liquid metallic hydrogen at high temperature and pressure. In this study, we perform ab initio calculations to study the solubility of an innermost metallic core. We find dissolution of iron to be strongly favored above 2000 K over the entire pressure range (0.4-4 TPa) considered. We compare with and summarize the results for solubilities on other probable core constituents. The calculations imply that giant planet cores are in thermodynamic disequilibrium with surrounding layers, promoting erosion and redistribution of heavy elements. Differences in solubility behavior between iron and rock may influence evolution of interiors, particularly for Saturn-mass planets. Understanding the distribution of iron and other heavy elements in gas giants may be relevant in understanding mass-radius relationships, as well as deviations in transport properties from pure hydrogen-helium mixtures

  13. Modeling hydrogen storage in boron-substituted graphene decorated with potassium metal atoms

    CSIR Research Space (South Africa)

    Tokarev, A

    2015-03-01

    Full Text Available Boron-substituted graphene decorated with potassium metal atoms was considered as a novel material for hydrogen storage. Density functional theory calculations were used to model key properties of the material, such as geometry, hydrogen packing...

  14. Hydrogen isotope exchange in a metal hydride tube

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, David B. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2014-09-01

    This report describes a model of the displacement of one hydrogen isotope within a metal hydride tube by a different isotope in the gas phase that is blown through the tube. The model incorporates only the most basic parameters to make a clear connection to the theory of open-tube gas chromatography, and to provide a simple description of how the behavior of the system scales with controllable parameters such as gas velocity and tube radius. A single tube can be seen as a building block for more complex architectures that provide higher molar flow rates or other advanced design goals.

  15. Dewetting Properties of Metallic Liquid Film on Nanopillared Graphene

    Science.gov (United States)

    Li, Xiongying; He, Yezeng; Wang, Yong; Dong, Jichen; Li, Hui

    2014-01-01

    In this work, we report simulation evidence that the graphene surface decorated by carbon nanotube pillars shows strong dewettability, which can give it great advantages in dewetting and detaching metallic nanodroplets on the surfaces. Molecular dynamics (MD) simulations show that the ultrathin liquid film first contracts then detaches from the graphene on a time scale of several nanoseconds, as a result of the inertial effect. The detaching velocity is in the order of 10 m/s for the droplet with radii smaller than 50 nm. Moreover, the contracting and detaching behaviors of the liquid film can be effectively controlled by tuning the geometric parameters of the liquid film or pillar. In addition, the temperature effects on the dewetting and detaching of the metallic liquid film are also discussed. Our results show that one can exploit and effectively control the dewetting properties of metallic nanodroplets by decorating the surfaces with nanotube pillars. PMID:24487279

  16. Dispersion relations of the acoustic modes in divalent liquid metals

    Directory of Open Access Journals (Sweden)

    Inui Masanori

    2017-01-01

    Full Text Available Collective dynamics in liquid Ca and liquid Cd was studied by inelastic x-ray scattering (IXS. Using our experimental technique to prepare proper sample cells and high performance of an IXS beamline (BL35XU at SPring-8 in Japan, the dynamic structure factor with reasonable statistics was obtained for these divalent liquid metals. For both liquids, the dynamic structure factor at low Q exhibits a central peak with a shoulder or small hump clearly visible on each side, and the inelastic excitation energy determined using the model function composed of Lorentzian and the damped harmonic oscillator function disperses with increasing Q. The dispersion curves of these liquids were compared with that of the longitudinal acoustic phonon in each crystalline phase. From these results, clear difference in the interatomic interaction be- tween liquid Ca and liquid Cd was inferred.

  17. Kinetics of hydrogen release from dissolutions of ammonia borane in different ionic liquids

    International Nuclear Information System (INIS)

    Valero-Pedraza, María José; Martín-Cortés, Alexandra; Navarrete, Alexander; Bermejo, María Dolores; Martín, Ángel

    2015-01-01

    Ammonia borane is a promising hydrogen storage material that liberates hydrogen by thermolysis at moderate temperatures, but it also presents major limitations for practical applications including a long induction time before the initiation of hydrogen release and a difficult regeneration. Previous works have demonstrated that by dissolution of ammonia borane into several ionic liquids, and particularly in 1-butyl-3-methylimidazolium chloride bmimCl, the induction period at the beginning of the thermolysis is eliminated, but some problems persist, including foaming and the formation of a residue after thermolysis that is insoluble in the ionic liquid. In this work, the release of hydrogen from ammonia borane dissolved in different ionic liquids has been analyzed, measuring the kinetics of hydrogen release, visually following the evolution of the sample during the process using pressure glass tube reactors, and analyzing the residue by spectroscopic techniques. While dissolutions of ammonia borane in most ionic liquids analyzed show similar properties as dissolutions in bmimCl, using ionic liquids with bis(trifluoromethylsulfanyl)imide Tf_2N anion the foaming problem is reduced, and in some cases the residue remains dissolved in the ionic liquid, while with ionic liquids with choline anion higher hydrogen yields are achieved that indicate that the decomposition of ammonia borane proceeds through a different path. - Highlights: • Hydrogen release from ammonia borane dissolved in 13 ionic liquids has been studied. • Induction time is shortened and hydrogen release rate is accelerated in all cases. • The best results are obtained using ionic liquids with Tf_2N anion. • Ch cation ionic liquids enable higher H_2 yield, but cyclotriborazane is produced.

  18. Oxidation of Group 8 transition-Metal Hydrides and Ionic Hydrogenation of Ketones and Aldehydes

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Kjell-Tore

    1996-08-01

    Transition-metal hydrides have received considerable attention during the last decades because of their unusual reactivity and their potential as homogeneous catalysts for hydrogenation and other reactions of organic substrates. An important class of catalytic processes where transition-metal hydrides are involved is the homogeneous hydrogenation of alkenes, alkynes, ketones, aldehydes, arenes and nitro compounds. This thesis studies the oxidation of Group 8 transition-metal hydrides and the ionic hydrogenation of ketones and aldehydes.

  19. Diagnosis of a Poorly Performing Liquid Hydrogen Bulk Storage Sphere

    Science.gov (United States)

    Krenn, Angela G.

    2011-01-01

    There are two 850,000 gallon Liquid Hydrogen (LH2) storage spheres used to support the Space Shuttle Program; one residing at Launch Pad A and the other at Launch Pad B. The LH2 Sphere at Pad B has had a high boiloff rate since being brought into service in the 1960's. The daily commodity loss was estimated to be approximately double that of the Pad A sphere, and well above the minimum required by the sphere's specification. Additionally, after being re-painted in the late 1990's a "cold spot" appeared on the outer sphere which resulted in a poor paint bond, and mold formation. Thermography was used to characterize the area, and the boiloff rate was continually evaluated. All evidence suggested that the high boiloff rate was caused by an excessive heat leak into the inner sphere due to an insulation void in the annulus. Pad B was recently taken out of Space Shuttle program service which provided a unique opportunity to diagnose the sphere's poor performance. The sphere was drained and inerted, and then opened from the annular relief device on the top where a series of boroscoping operations were accomplished. Boroscoping revealed a large Perlite insulation void in the region of the sphere where the cold spot was apparent. Perlite was then trucked in and off-loaded into the annular void region until the annulus was full. The sphere has not yet been brought back into service.

  20. Renewable energy carriers: Hydrogen or liquid air/nitrogen?

    International Nuclear Information System (INIS)

    Li Yongliang; Chen Haisheng; Zhang Xinjing; Tan Chunqing; Ding Yulong

    2010-01-01

    The world's energy demand is met mainly by the fossil fuels today. The use of such fuels, however, causes serious environmental issues, including global warming, ozone layer depletion and acid rains. A sustainable solution to the issues is to replace the fossil fuels with renewable ones. Implementing such a solution, however, requires overcoming a number of technological barriers including low energy density, intermittent supply and mobility of the renewable energy sources. A potential approach to overcoming these barriers is to use an appropriate energy carrier, which can store, transport and distribute energy. The work to be reported in this paper aims to assess and compare a chemical energy carrier, hydrogen, with a physical energy carrier, liquid air/nitrogen, and discuss potential applications of the physical carrier. The ocean energy is used as an example of the renewable energy sources in the work. The assessment and comparison are carried out in terms of the overall efficiency, including production, storage/transportation and energy extraction. The environmental impact, waste heat recovery and safety issues are also considered. It is found that the physical energy carrier may be a better alternative to the chemical energy carrier under some circumstances, particularly when there are waste heat sources.

  1. Towards hydrogen metallization: an Ab initio approach; Vers la metallisation de l`hydrogene: approche AB initio

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, St

    1999-12-31

    The quest for metallic hydrogen is a major goal for both theoretical and experimental condensed matter physics. Hydrogen and deuterium have been compressed up to 200 GPa in diamond anvil cells, without any clear evidence for a metallic behaviour. Loubeyere has recently suggested that hydrogen could metallize, at pressures within experimental range, in a new Van der Waals compound: Ar(H{sub 2}){sub 2} which is characterized at ambient pressure by an open and anisotropic sublattice of hydrogen molecules, stabilized by an argon skeleton. This thesis deals with a detailed ab initio investigation, by Car-Parrinello molecular dynamics methods, of the evolution under pressure of this compound. In a last chapter, we go to much higher pressures and temperatures, in order to compare orbital and orbital free ab initio methods for the dense hydrogen plasma. (author) 109 refs.

  2. Towards hydrogen metallization: an Ab initio approach; Vers la metallisation de l`hydrogene: approche AB initio

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, St

    1998-12-31

    The quest for metallic hydrogen is a major goal for both theoretical and experimental condensed matter physics. Hydrogen and deuterium have been compressed up to 200 GPa in diamond anvil cells, without any clear evidence for a metallic behaviour. Loubeyere has recently suggested that hydrogen could metallize, at pressures within experimental range, in a new Van der Waals compound: Ar(H{sub 2}){sub 2} which is characterized at ambient pressure by an open and anisotropic sublattice of hydrogen molecules, stabilized by an argon skeleton. This thesis deals with a detailed ab initio investigation, by Car-Parrinello molecular dynamics methods, of the evolution under pressure of this compound. In a last chapter, we go to much higher pressures and temperatures, in order to compare orbital and orbital free ab initio methods for the dense hydrogen plasma. (author) 109 refs.

  3. Density dependent atomic motion in a liquid alkali metal

    International Nuclear Information System (INIS)

    Pilgrim, W.-C.; Hosokawa, S.; Morkel, C.

    2001-01-01

    Inelastic X-ray and neutron scattering results obtained from liquid sodium and rubidium are presented. They cover the entire liquid range between melting and liquid vapour critical point. At high densities the dynamics of the liquid metal is characterized by collective excitations. The corresponding dispersion relations indicate the existence of surprisingly stable next neighbouring shells leading to an increase of the propagation speed for the collective modes. Below 2ρ crit. the dynamics changes from collective to localized indicating the existence of molecular aggregates. This interpretation is in accord with a simple model where the properties of a Rb- and a Rb 2 - lattice are calculated using density functional theory. (orig.)

  4. Hydrogen release at metal-oxide interfaces: A first principle study of hydrogenated Al/SiO{sub 2} interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jianqiu, E-mail: jianqiu@vt.edu [Department of Mechanical Engineering, Virginia Tech, Goodwin Hall, 635 Prices Fork Road - MC 0238, Blacksburg, VA 24061 (United States); Tea, Eric; Li, Guanchen [Department of Mechanical Engineering, Virginia Tech, Goodwin Hall, 635 Prices Fork Road - MC 0238, Blacksburg, VA 24061 (United States); Hin, Celine [Department of Mechanical Engineering, Virginia Tech, Goodwin Hall, 635 Prices Fork Road - MC 0238, Blacksburg, VA 24061 (United States); Department of Material Science and Engineering, Virginia Tech, Goodwin Hall, 635 Prices Fork Road-MC 0238, Blacksburg, VA 24061 (United States)

    2017-06-01

    Highlights: • Hydrogen release process at the Al/SiO{sub 2} metal-oxide interface has been investigated. • A mathematical model that estimates the hydrogen release potential has been proposed. • Al atoms, Al−O bonds, and Si−Al bonds are the major hydrogen traps at the Al/SiO{sub 2} interface. • Hydrogen atoms are primarily release from Al−H and O−H bonds at the Al/SiO{sub 2} metal-oxide interface. - Abstract: The Anode Hydrogen Release (AHR) mechanism at interfaces is responsible for the generation of defects, that traps charge carriers and can induce dielectric breakdown in Metal-Oxide-Semiconductor Field Effect Transistors. The AHR has been extensively studied at Si/SiO{sub 2} interfaces but its characteristics at metal-silica interfaces remain unclear. In this study, we performed Density Functional Theory (DFT) calculations to study the hydrogen release mechanism at the typical Al/SiO{sub 2} metal-oxide interface. We found that interstitial hydrogen atoms can break interfacial Al−Si bonds, passivating a Si sp{sup 3} orbital. Interstitial hydrogen atoms can also break interfacial Al−O bonds, or be adsorbed at the interface on aluminum, forming stable Al−H−Al bridges. We showed that hydrogenated O−H, Si−H and Al−H bonds at the Al/SiO{sub 2} interfaces are polarized. The resulting bond dipole weakens the O−H and Si−H bonds, but strengthens the Al−H bond under the application of a positive bias at the metal gate. Our calculations indicate that Al−H bonds and O−H bonds are more important than Si−H bonds for the hydrogen release process.

  5. Metal decontamination for waste minimization using liquid metal refining technology

    International Nuclear Information System (INIS)

    Joyce, E.L. Jr.; Lally, B.; Ozturk, B.; Fruehan, R.J.

    1993-01-01

    The current Department of Energy Mixed Waste Treatment Project flowsheet indicates that no conventional technology, other than surface decontamination, exists for metal processing. Current Department of Energy guidelines require retrievable storage of all metallic wastes containing transuranic elements above a certain concentration. This project is in support of the National Mixed Low Level Waste Treatment Program. Because of the high cost of disposal, it is important to develop an effective decontamination and volume reduction method for low-level contaminated metals. It is important to be able to decontaminate complex shapes where surfaces are hidden or inaccessible to surface decontamination processes and destruction of organic contamination. These goals can be achieved by adapting commercial metal refining processes to handle radioactive and organic contaminated metal. The radioactive components are concentrated in the slag, which is subsequently vitrified; hazardous organics are destroyed by the intense heat of the bath. The metal, after having been melted and purified, could be recycled for use within the DOE complex. In this project, we evaluated current state-of-the-art technologies for metal refining, with special reference to the removal of radioactive contaminants and the destruction of hazardous organics. This evaluation was based on literature reports, industrial experience, plant visits, thermodynamic calculations, and engineering aspects of the various processes. The key issues addressed included radioactive partitioning between the metal and slag phases, minimization of secondary wastes, operability of the process subject to widely varying feed chemistry, and the ability to seal the candidate process to prevent the release of hazardous species

  6. Performance study of a hydrogen powered metal hydride actuator

    International Nuclear Information System (INIS)

    Bhuiya, Md Mainul Hossain; Kim, Kwang J

    2016-01-01

    A thermally driven hydrogen powered actuator integrating metal hydride hydrogen storage reactor, which is compact, noiseless, and able to generate smooth actuation, is presented in this article. To test the plausibility of a thermally driven actuator, a conventional piston type actuator was integrated with LaNi 5 based hydrogen storage system. Copper encapsulation followed by compaction of particles into pellets, were adopted to improve overall thermal conductivity of the reactor. The operation of the actuator was thoroughly investigated for an array of operating temperature ranges. Temperature swing of the hydride reactor triggering smooth and noiseless actuation over several operating temperature ranges were monitored for quantification of actuator efficiency. Overall, the actuator generated smooth and consistent strokes during repeated cycles of operation. The efficiency of the actuator was found to be as high as 13.36% for operating a temperature range of 20 °C–50 °C. Stress–strain characteristics, actuation hysteresis etc were studied experimentally. Comparison of stress–strain characteristics of the proposed actuator with traditional actuators, artificial muscles and so on was made. The study suggests that design modification and use of high pressure hydride may enhance the performance and broaden the application horizon of the proposed actuator in future. (paper)

  7. Molecular metal-Oxo catalysts for generating hydrogen from water

    Science.gov (United States)

    Long, Jeffrey R; Chang, Christopher J; Karunadasa, Hemamala I

    2015-02-24

    A composition of matter suitable for the generation of hydrogen from water is described, the positively charged cation of the composition having the general formula [(PY5W.sub.2)MO].sup.2+, wherein PY5W.sub.2 is (NC.sub.5XYZ)(NC.sub.5H.sub.4).sub.4C.sub.2W.sub.2, M is a transition metal, and W, X, Y, and Z can be H, R, a halide, CF.sub.3, or SiR.sub.3, where R can be an alkyl or aryl group. The two accompanying counter anions, in one embodiment, can be selected from the following Cl.sup.-, I.sup.-, PF.sub.6.sup.-, and CF.sub.3SO.sub.3.sup.-. In embodiments of the invention, water, such as tap water containing electrolyte or straight sea water can be subject to an electric potential of between 1.0 V and 1.4 V relative to the standard hydrogen electrode, which at pH 7 corresponds to an overpotential of 0.6 to 1.0 V, with the result being, among other things, the generation of hydrogen with an optimal turnover frequency of ca. 1.5 million mol H.sub.2/mol catalyst per h.

  8. Hydrogen Storage Engineering Center of Excellence Metal Hydride Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Motyka, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2014-05-31

    The Hydrogen Storage Engineering Center of Excellence (HSECoE) was established in 2009 by the U.S. Department of Energy (DOE) to advance the development of materials-based hydrogen storage systems for hydrogen-fueled light-duty vehicles. The overall objective of the HSECoE is to develop complete, integrated system concepts that utilize reversible metal hydrides, adsorbents, and chemical hydrogen storage materials through the use of advanced engineering concepts and designs that can simultaneously meet or exceed all the DOE targets. This report describes the activities and accomplishments during Phase 1 of the reversible metal hydride portion of the HSECoE, which lasted 30 months from February 2009 to August 2011. A complete list of all the HSECoE partners can be found later in this report but for the reversible metal hydride portion of the HSECoE work the major contributing organizations to this effort were the United Technology Research Center (UTRC), General Motors (GM), Pacific Northwest National Laboratory (PNNL), the National Renewable Energy Laboratory (NREL) and the Savannah River National Laboratory (SRNL). Specific individuals from these and other institutions that supported this effort and the writing of this report are included in the list of contributors and in the acknowledgement sections of this report. The efforts of the HSECoE are organized into three phases each approximately 2 years in duration. In Phase I, comprehensive system engineering analyses and assessments were made of the three classes of storage media that included development of system level transport and thermal models of alternative conceptual storage configurations to permit detailed comparisons against the DOE performance targets for light-duty vehicles. Phase 1 tasks also included identification and technical justifications for candidate storage media and configurations that should be capable of reaching or exceeding the DOE targets. Phase 2 involved bench-level testing and

  9. Liquid phase and supercooled liquid phase welding of bulk metallic glasses

    International Nuclear Information System (INIS)

    Kawamura, Y.

    2004-01-01

    Recent progress on welding in bulk metallic glasses (BMGs) has been reviewed. BMGs have been successfully welded to BMGs or crystalline metals by liquid phase welding using explosion, pulse-current and electron-beam methods, and by supercooled liquid phase welding using friction method. Successful welding of the liquid phase methods was due to the high glass-forming ability of the BMGs and the high concentration of welding energy in these methods. In contrast, the supercooled liquid phase welding was successful due to the thermally stable supercooled liquid state of the BMGs and the superplasticity and viscous flow of the supercooled liquid. The successful welding of BMGs to BMGs and crystalline materials is promising for the future development of BMGs as engineering materials

  10. Hydrogen Storage using Metal Hydrides in a Stationary Cogeneration System

    International Nuclear Information System (INIS)

    Botzung, Maxime; Chaudourne, Serge; Perret, Christian; Latroche, Michel; Percheron-Guegan, Annick; Marty Philippe

    2006-01-01

    In the frame of the development of a hydrogen production and storage unit to supply a 40 kW stationary fuel cell, a metal hydride storage tank was chosen according to its reliability and high energetic efficiency. The study of AB5 compounds led to the development of a composition adapted to the project needs. The absorption/desorption pressures of the hydride at 75 C (2 / 1.85 bar) are the most adapted to the specifications. The reversible storage capacity (0.95 %wt) has been optimized to our work conditions and chemical kinetics is fast. The design of the Combined Heat and Power CHP system requires 5 kg hydrogen storage but in a first phase, only a 0.1 kg prototype has been realised and tested. Rectangular design has been chosen to obtain good compactness with an integrated plate fin type heat exchanger designed to reach high absorption/desorption rates. In this paper, heat and mass transfer characteristics of the Metal Hydride tank (MH tank) during absorption/desorption cycles are given. (authors)

  11. Liquid metal batteries - materials selection and fluid dynamics

    Science.gov (United States)

    Weier, T.; Bund, A.; El-Mofid, W.; Horstmann, G. M.; Lalau, C.-C.; Landgraf, S.; Nimtz, M.; Starace, M.; Stefani, F.; Weber, N.

    2017-07-01

    Liquid metal batteries are possible candidates for massive and economically feasible large-scale stationary storage and as such could be key components of future energy systems based mainly or exclusively on intermittent renewable electricity sources. The completely liquid interior of liquid metal batteries and the high current densities give rise to a multitude of fluid flow phenomena that will primarily influence the operation of future large cells, but might be important for today’s smaller cells as well. The paper at hand starts with a discussion of the relative merits of using molten salts or ionic liquids as electrolytes for liquid metal cells and touches the choice of electrode materials. This excursus into electrochemistry is followed by an overview of investigations on magnetohydrodynamic instabilities in liquid metal batteries, namely the Tayler instability and electromagnetically excited gravity waves. A section on electro-vortex flows complements the discussion of flow phenomena. Focus of the flow related investigations lies on the integrity of the electrolyte layer and related critical parameters.

  12. Review of the critical heat flux correlations for liquid metals

    International Nuclear Information System (INIS)

    Lee, Yong Bum; Han, H. D.; Chang, W. P.; Kwon, Y. M.

    1999-09-01

    The CHF phenomenon in the two-phase convective flows has been an important issue in the fields of design and safety analysis of light water reactor (LWR) as well as sodium cooled liquid metal reactor (LMR). Especially in the LWR application, many physical aspects of the CHF phenomenon are understood and reliable correlations and mechanistic models to predict the CHF condition have been proposed over the past three decades. Most of the existing CHF correlations have been developed for light water reactor core applications. Compared with water, liquid metals show a divergent picture of boiling pattern. This can be attributed to the consequence that special CHF conditions obtained from investigations with water cannot be applied to liquid metals. Numerous liquid metal boiling heat transfer and two-phase flow studies have put emphasis on development of models and understanding of the mechanism for improving the CHF predictions. Thus far, no overall analytical solution method has been obtained and the reliable prediction method has remained empirical. The principal objectives of the present report are to review the state of the art in connection with liquid metal critical heat flux under low pressure and low flow conditions and to discuss the basic mechanisms. (author)

  13. Emergency cooling system for a liquid metal cooled reactor

    International Nuclear Information System (INIS)

    Murata, Ryoichi; Fujiwara, Toshikatsu.

    1980-01-01

    Purpose: To suitably cool liquid metal as coolant in emergency in a liquid metal cooled reactor by providing a detector for the pressure loss of the liquid metal passing through a cooling device in a loop in which the liquid metal is flowed and communicating the detector with a coolant flow regulator. Constitution: A nuclear reactor is stopped in nuclear reaction by control element or the like in emergency. If decay heat is continuously generated for a while and secondary coolant is insufficiently cooled with water or steam flowed through a steam and water loop, a cooler is started. That is, low temperature air is supplied by a blower through an inlet damper to the cooler to cool the secondary coolant flowed into the cooler through a bypass pipe so as to finally safely stop an entire plant. Since the liquid metal is altered in its physical properties by the temperature at this time, it is detected to regulate the opening of the valve of the damper according to the detected value. (Sekiya, K.)

  14. Key study on the potential of hydrazine bisborane for solid- and liquid-state chemical hydrogen storage.

    Science.gov (United States)

    Pylypko, Sergii; Petit, Eddy; Yot, Pascal G; Salles, Fabrice; Cretin, Marc; Miele, Philippe; Demirci, Umit B

    2015-05-04

    Hydrazine bisborane N2H4(BH3)2 (HBB; 16.8 wt %) recently re-emerged as a potential hydrogen storage material. However, such potential is controversial: HBB was seen as a hazardous compound up to 2010, but now it would be suitable for hydrogen storage. In this context, we focused on fundamentals of HBB because they are missing in the literature and should help to shed light on its effective potential while taking into consideration any risk. Experimental/computational methods were used to get a complete characterization data sheet, including, e.g., XRD, NMR, FTIR, Raman, TGA, and DSC. From the reported results and discussion, it is concluded that HBB has potential in the field of chemical hydrogen storage given that both thermolytic and hydrolytic dehydrogenations were analyzed. In solid-state chemical hydrogen storage, it cannot be used in the pristine state (risk of explosion during dehydrogenation) but can be used for the synthesis of derivatives with improved dehydrogenation properties. In liquid-state chemical hydrogen storage, it can be studied for room-temperature dehydrogenation, but this requires the development of an active and selective metal-based catalyst. HBB is a thus a candidate for chemical hydrogen storage.

  15. An assessment of the government liquid hydrogen requirements for the 1995-2005 time frame including addendum, liquid hydrogen production and commercial demand in the United States

    Science.gov (United States)

    Bain, Addison

    1990-01-01

    Liquid hydrogen will continue to be an integral element in virtually every major space program, and it has also become a significant merchant product for certain commercial markets. Liquid hydrogen is not a universally available commodity, and the number of supply sources historically have been limited to regions having concentrated consumption patterns. With the increased space program activity it becomes necessary to assess all future programs on a collective and unified basis. An initial attempt to identify projected requirements on a long range basis is presented.

  16. Primary metals extraction by liquid membranes

    International Nuclear Information System (INIS)

    Subramanian, K.N.

    1980-01-01

    The extraction of copper and uranium by liquid membranes is presented. The recovery of uranium from wet process phosphoric acid is described. The development of this process has progressed through three stages, firstly the chemistry of uranium extraction as it pertains to liquid membrane systems. This was followed by continuous extraction tests on fresh black acid and on aged acid. Results on a 1 litre/minute pilot plant demonstrated that the process could be operated with a minimum of feed pretreatment and about 90% of uranium could be extracted. The extraction of copper from copper leach liquors is also described. (U.K.)

  17. Hydrogen Sensors Using Nitride-Based Semiconductor Diodes: The Role of Metal/Semiconductor Interfaces

    Directory of Open Access Journals (Sweden)

    Yoshihiro Irokawa

    2011-01-01

    Full Text Available In this paper, I review my recent results in investigating hydrogen sensors using nitride-based semiconductor diodes, focusing on the interaction mechanism of hydrogen with the devices. Firstly, effects of interfacial modification in the devices on hydrogen detection sensitivity are discussed. Surface defects of GaN under Schottky electrodes do not play a critical role in hydrogen sensing characteristics. However, dielectric layers inserted in metal/semiconductor interfaces are found to cause dramatic changes in hydrogen sensing performance, implying that chemical selectivity to hydrogen could be realized. The capacitance-voltage (C-V characteristics reveal that the work function change in the Schottky metal is not responsible mechanism for hydrogen sensitivity. The interface between the metal and the semiconductor plays a critical role in the interaction of hydrogen with semiconductor devises. Secondly, low-frequency C-V characterization is employed to investigate the interaction mechanism of hydrogen with diodes. As a result, it is suggested that the formation of a metal/semiconductor interfacial polarization could be attributed to hydrogen-related dipoles. In addition, using low-frequency C-V characterization leads to clear detection of 100 ppm hydrogen even at room temperature where it is hard to detect hydrogen by using conventional current-voltage (I-V characterization, suggesting that low-frequency C-V method would be effective in detecting very low hydrogen concentrations.

  18. Comparison of the renewable transportation fuels, liquid hydrogen and methanol, with gasoline - energetic and economic aspects

    International Nuclear Information System (INIS)

    Specht, M.; Staiss, F.; Bandi, A.; Weimer, T.

    1998-01-01

    In this paper, the renewable energy vectors liquid hydrogen (LH 2 ) and methanol generated from atmospheric CO 2 are compared with the conventional crude oil-gasoline system. Both renewable concepts, liquid hydrogen and methanol, lead to a drastic CO 2 reduction compared to the fossil-based system. The comparison between the LH 2 and methanol vector for the transport sector shows nearly the same fuel cost and energy efficiency but strong infrastructure advantages for methanol. (author)

  19. A large economic liquid metal reactor for United States utilities

    International Nuclear Information System (INIS)

    Rodwell, E.

    1985-01-01

    The United States has demonstrated its ability to build and operate small and medium sized liquid metal reactors and continues to operate the Experimental Breeder Reactor II and the Fast Flux Test Facility to demonstrate long life fuel designs. Similar-sized liquid metal reactors in Europe have been followed by a step-up to the 1200 MWe capacity of the Superphenix plant. To permit the United States to make a similar step-up in capacity, a 1320 MWe liquid metal reactor plant has been designed with the main emphasis on minimizing the specific capital cost in order to be competitive with light water reactor plant and fossil plant alternatives. The design is based on a four parallel heat transport loops arrangement and complies with current regulatory requirements. The primary heat transport loops are now being integrated into the reactor vessel to achieve further reduction in the capital cost

  20. Review of liquid metal heat pipe work at Los Alamos

    International Nuclear Information System (INIS)

    Reid, R.S.; Merrigan, M.A.; Sena, J.T.

    1990-01-01

    A survey of space-power related liquid metal heat pipe work at Los Alamos National Laboratory is presented. Heat pipe development at Los Alamos has been on-going since 1963. Heat pipes were initially developed for thermionic nuclear-electrical power production in space. Since then Los Alamos has developed liquid metal heat pipes for numerous applications related to high temperature systems in both the space and terrestrial environments. Some of these applications include thermionic electrical generators, thermoelectric energy conversion (both in-core and direct radiation), thermal energy storage, hypersonic vehicle leading edge cooling, and heat pipe vapor laser cells. Some of the work performed at Los Alamos has been documented in internal reports that are often little-known. A representative description and summary of progress in space-related liquid metal heat pipe technology is provided followed by a reference section citing sources where these works may be found. 53 refs

  1. Temperature-dependent liquid metal flowrate control device

    International Nuclear Information System (INIS)

    Carlson, R.D.

    1978-01-01

    A temperature-dependent liquid metal flowrate control device includes a magnet and a ferromagnetic member defining therebetween a flow path for liquid metal, the ferromagnetic member being formed of a material having a curie temperature at which a change in the flow rate of the liquid metal is desired. According to the preferred embodiment the magnet is a cylindrical rod magnet axially disposed within a cylindrical member formed of a curie material and having iron pole pieces at the ends. A cylindrical iron shunt and a thin wall stainless steel barrier are disposed in the annulus between magnet and curie material. Below the curie temperature flow between steel barrier and curie material is impeded and above the curie temperature flow impedance is reduced

  2. Stretchable Metamaterial Absorber Using Liquid Metal-Filled Polydimethylsiloxane (PDMS

    Directory of Open Access Journals (Sweden)

    Kyeongseob Kim

    2016-04-01

    Full Text Available A stretchable metamaterial absorber is proposed in this study. The stretchability was achieved by liquid metal and polydimethylsiloxane (PDMS. To inject liquid metal, microfluidic channels were fabricated using PDMS powers and microfluidic-channel frames, which were built using a three-dimensional printer. A top conductive pattern and ground plane were designed after considering the easy injection of liquid metal. The proposed metamaterial absorber comprises three layers of PDMS substrate. The top layer is for the top conductive pattern, and the bottom layer is for the meandered ground plane. Flat PDMS layers were inserted between the top and bottom PDMS layers. The measured absorptivity of the fabricated absorber was 97.8% at 18.5 GHz, and the absorption frequency increased from 18.5 to 18.65 GHz as the absorber was stretched from its original length (5.2 cm to 6.4 cm.

  3. Liquid metal flow control by DC electromagnetic pumps

    International Nuclear Information System (INIS)

    Borges, Eduardo Madeira; Braz Filho, Francisco Antonio; Guimaraes, Lamartine Nogueira Frutuoso

    2006-01-01

    The cooling system of high-density thermal power requires fluids of high thermal conductivity, such as liquid metals. Electromagnetic pumps can be used to liquid metal fluid flow control in cooling circuits. The operation of electromagnetic pumps used to flow control is based on Lorentz force. This force can be achieved by magnetic field and electric current interaction, controlled by external independent power supplies. This work presents the electromagnetic pump operational principles, the IEAv development scheme and the BEMC-1 simulation code. The theoretical results of BEMC-1 simulation are compared to electromagnetic pump operation experimental data, validating the BEMC-1 code. This code is used to evaluate the DC electromagnetic pump performance applied to Mercury flow control and others liquid metal such as Sodium, Lead and Bismuth, used in nuclear fast reactors. (author)

  4. Reactions of oxygen and hydrogen with liquid sodium - a critical survey

    International Nuclear Information System (INIS)

    Ullmann, H.

    1982-01-01

    The fundamentals of solvation chemistry are presented with appropriate components formulated. Methods of investigation and kinetics of the reactions are described. The hydrogen equilibrium pressure and saturation solubilities are described. The chemical equilibrium between O and H in solution is presented with detailed tabulation of the saturation solutions of oxygen, hydrogen and hydroxide in liquid sodium. Agreements and differences with the literature are presented

  5. Alcohol-responsive, hydrogen-bonded, cholesteric liquid-crystal networks

    NARCIS (Netherlands)

    Chang, C.; Bastiaansen, C.W.M.; Broer, D.J.; Kuo, H.-L.

    2012-01-01

    Hydrogen-bridged, cholesteric liquid-crystal (CLC) polymer networks are adopted as an optical sensor material to distinguish between ethanol and methanol. Fast uptake of the alcohols is facilitated by an incorporated porosity created by breaking the hydrogen bridges and by a previously removed

  6. Development of a Hemispherical Metal Diaphragm for Single-Cycle Liquid-Metal Positive Expulsion Systems

    National Research Council Canada - National Science Library

    Gorland, Sol

    1965-01-01

    This report presents experimental results pertaining to the design and development of a metallic expulsion diaphragm for single-cycle positive expulsion of high-temperature liquid in an agravity condition...

  7. Liquid state properties of certain noble and transition metals

    International Nuclear Information System (INIS)

    Bhuiyan, G.M.; Rahman, A.; Khaleque, M.A.; Rashid, R.I.M.A.; Mujibur Rahman, S.M.

    1998-07-01

    Certain structural, thermodynamic and atomic transport properties of a number of liquid noble and transition metals are reported. The underlying theory combines together a simple form of the N-body potential and the thermodynamically self-consistent variational modified hypernetted chain (VMHNC) theory of liquid. The static structure factors calculated by using the VMHNC resemble the hard sphere (HS) values. Consequently the HS model is used to calculate the thermodynamic properties viz. specific heat, entropy, isothermal compressibility and atomic transport properties. (author)

  8. Hydrogen and dihydrogen bonding of transition metal hydrides

    International Nuclear Information System (INIS)

    Jacobsen, Heiko

    2008-01-01

    Intermolecular interactions between a prototypical transition metal hydride WH(CO) 2 NO(PH 3 ) 2 and a small proton donor H 2 O have been studied using DFT methodology. The hydride, nitrosyl and carbonyl ligand have been considered as site of protonation. Further, DFT-D calculations in which empirical corrections for the dispersion energy are included, have been carried out. A variety of pure and hybrid density functionals (BP86, PW91, PBE, BLYP, OLYP, B3LYP, B1PW91, PBE0, X3LYP) have been considered, and our calculations indicate the PBE functional and its hybrid variation are well suited for the calculation of transition metal hydride hydrogen and dihydrogen bonding. Dispersive interactions make up for a sizeable portion of the intermolecular interaction, and amount to 20-30% of the bond energy and to 30-40% of the bond enthalpy. An energy decomposition analysis reveals that the H...H bond of transition metal hydrides contains both covalent and electrostatic contributions

  9. Hydrogen and dihydrogen bonding of transition metal hydrides

    Science.gov (United States)

    Jacobsen, Heiko

    2008-04-01

    Intermolecular interactions between a prototypical transition metal hydride WH(CO) 2NO(PH 3) 2 and a small proton donor H 2O have been studied using DFT methodology. The hydride, nitrosyl and carbonyl ligand have been considered as site of protonation. Further, DFT-D calculations in which empirical corrections for the dispersion energy are included, have been carried out. A variety of pure and hybrid density functionals (BP86, PW91, PBE, BLYP, OLYP, B3LYP, B1PW91, PBE0, X3LYP) have been considered, and our calculations indicate the PBE functional and its hybrid variation are well suited for the calculation of transition metal hydride hydrogen and dihydrogen bonding. Dispersive interactions make up for a sizeable portion of the intermolecular interaction, and amount to 20-30% of the bond energy and to 30-40% of the bond enthalpy. An energy decomposition analysis reveals that the H⋯H bond of transition metal hydrides contains both covalent and electrostatic contributions.

  10. Hydrogen and dihydrogen bonding of transition metal hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Jacobsen, Heiko [KemKom, Libellenweg 2, 25917 Leck, Nordfriesland (Germany)], E-mail: jacobsen@kemkom.com

    2008-04-03

    Intermolecular interactions between a prototypical transition metal hydride WH(CO){sub 2}NO(PH{sub 3}){sub 2} and a small proton donor H{sub 2}O have been studied using DFT methodology. The hydride, nitrosyl and carbonyl ligand have been considered as site of protonation. Further, DFT-D calculations in which empirical corrections for the dispersion energy are included, have been carried out. A variety of pure and hybrid density functionals (BP86, PW91, PBE, BLYP, OLYP, B3LYP, B1PW91, PBE0, X3LYP) have been considered, and our calculations indicate the PBE functional and its hybrid variation are well suited for the calculation of transition metal hydride hydrogen and dihydrogen bonding. Dispersive interactions make up for a sizeable portion of the intermolecular interaction, and amount to 20-30% of the bond energy and to 30-40% of the bond enthalpy. An energy decomposition analysis reveals that the H...H bond of transition metal hydrides contains both covalent and electrostatic contributions.

  11. Development of oxygen sensors for use in liquid metal

    International Nuclear Information System (INIS)

    Van Nieuwenhove, Rudi; Ejenstam, Jesper; Szakalos, Peter

    2015-01-01

    For generation IV reactor concepts, based on liquid metal cooling, there is a need for robust oxygen sensors which can be used in the core of the reactor since corrosion can only be kept sufficiently low by controlling the dissolved oxygen content in the liquid metal. A robust, ceramic membrane type sensor has been developed at IFE/Halden (Norway) and tested in an autoclave system at KTH (Sweden). The sensor has been tested in lead-bismuth at 550 deg. C and performed well. (authors)

  12. Development of oxygen sensors for use in liquid metal

    Energy Technology Data Exchange (ETDEWEB)

    Van Nieuwenhove, Rudi [Institutt for Energiteknikk, Halden, (Norway); Ejenstam, Jesper; Szakalos, Peter [KTH Royal Institute of Technology, Division of Surface and Corrosion Science, Stockholm, (Sweden)

    2015-07-01

    For generation IV reactor concepts, based on liquid metal cooling, there is a need for robust oxygen sensors which can be used in the core of the reactor since corrosion can only be kept sufficiently low by controlling the dissolved oxygen content in the liquid metal. A robust, ceramic membrane type sensor has been developed at IFE/Halden (Norway) and tested in an autoclave system at KTH (Sweden). The sensor has been tested in lead-bismuth at 550 deg. C and performed well. (authors)

  13. Single-magnet rotary flowmeter for liquid metals

    OpenAIRE

    Priede, Jānis; Buchenau, Dominique; Gerbeth, Gunter

    2010-01-01

    We present a theory of single-magnet flowmeter for liquid metals and compare it with experimental results. The flowmeter consists of a freely rotating permanent magnet, which is magnetized perpendicularly to the axle it is mounted on. When such a magnet is placed close to a tube carrying liquid metal flow, it rotates so that the driving torque due to the eddy currents induced by the flow is balanced by the braking torque induced by the rotation itself. The equilibrium rotation rate, which var...

  14. Performance and safety design of the advanced liquid metal reactor

    International Nuclear Information System (INIS)

    Berglund, R.C.; Magee, P.M.; Boardman, C.E.; Gyorey, G.L.

    1991-01-01

    The Advanced Liquid Metal Reactor (ALMR) program led by General Electric is developing, under U.S. Department of Energy sponsorship, a conceptual design for an advanced sodium-cooled liquid metal reactor plant. This design is intended to improve the already excellent level of plant safety achieved by the nuclear power industry while at the same time providing significant reductions in plant construction and operating costs. In this paper, the plant design and performance are reviewed, with emphasis on the ALMR's unique passive design safety features and its capability to utilize as fuel the actinides in LWR spent fuel

  15. Interaction of hydrogen and oxygen with bulk defects and surfaces of metals

    International Nuclear Information System (INIS)

    Besenbacher, F.

    1994-05-01

    The thesis deals with the interaction of hydrogen with defects in metals and the interaction of hydrogen and oxygen with metal surfaces studied by ion-beam techniques and scanning tunneling microscopy (STM), respectively. The first part of the thesis discusses the interaction of hydrogen with simple defects in transition metals. The trap-binding enthalpies and the lattice location of hydrogen trapped to vacancies have been determined, and an extremely simple and versatile picture of the hydrogen-metal interaction has evolved, in which the trap strength is mainly determined by the local electron density. Any dilution of the lattice will lead to a trap, vacancies and voids being the strongest trap. It is found that hydrogen trapped to vacancies in fcc metals is quantum-mechanically delocalized, and the excitation energies for the hydrogen in the vacancy potential are a few MeV only. The interaction of hydrogen with metal surfaces is studied by the transmission channeling (TC) technique. It is found that hydrogen chemisorbs in the highest-coordinated sites on the surfaces, and that there is a direct relationship between the hydrogen-metal bond length and the coordination number for the hydrogen. In the final part of the thesis the dynamics of the chemisorption process for oxygen and hydrogen on metal surfaces is studied by STM, a fascinating and powerful technique for exploring the atomic-scale realm of surfaces. It is found that there is a strong coupling between the chemisorption process and the distortion of the metal surface. The adsorbates induce a surface reconstruction, i.e. metal-metal bond breaks and metal-adsorbate bounds form. Whereas hydrogen interacts weakly with the metals and induces reconstructions where only nnn metals bonds are broken, oxygen interacts strongly with the metal, and the driving force for the O-induced reconstructions appears to be the formation of low-coordinated metal-O rows, formed by breaking of nn metal bonds. Finally it is shown

  16. The solubility of metals in Pb-17Li liquid alloy

    International Nuclear Information System (INIS)

    Borgstedt, H.U.; Feuerstein, H.

    1992-01-01

    The solubility data of iron in the eutectic alloy Pb-17Li which were evaluated from corrosion tests in a turbulent flow of the molten alloy are discussed in the frame of solubilities of the transition metals in liquid lead. It is shown that the solubility of iron in the alloy is close to that in lead. This is also the fact for several other alloying elements of steels. A comparison of all known data shows that they are in agreement with generally shown trends for the solubility of the transition metals in low melting metals. These trends indicate comparably high solubilities of nickel and manganese in the liquid metals, lower saturation concentration of vanadium, chromium, iron, and cobalt, and extremely low solubility of molybdenum. (orig.)

  17. Review of the methods to form hydrogen peroxide in electrical discharge plasma with liquid water

    Science.gov (United States)

    Locke, Bruce R.; Shih, Kai-Yuan

    2011-06-01

    This paper presents a review of the literature dealing with the formation of hydrogen peroxide from plasma processes. Energy yields for hydrogen peroxide generation by plasma from water span approximately three orders of magnitude from 4 × 10-2 to 80 g kWh-1. A wide range of plasma processes from rf to pulsed, ac, and dc discharges directly in the liquid phase have similar energy yields and may thus be limited by radical quenching processes at the plasma-liquid interface. Reactor modification using discharges in bubbles and discharges over the liquid phase can provide modest improvements in energy yield over direct discharge in the liquid, but the interpretation is complicated by additional chemical reactions of gas phase components such as ozone and nitrogen oxides. The highest efficiency plasma process utilizes liquid water droplets that may enhance efficiency by sequestering hydrogen peroxide in the liquid and by suppressing decomposition reactions by radicals from the gas and at the interface. Kinetic simulations of water vapor reported in the literature suggest that plasma generation of hydrogen peroxide should approach 45% of the thermodynamics limit, and this fact coupled with experimental studies demonstrating improvements with the presence of the condensed liquid phase suggest that further improvements in energy yield may be possible. Plasma generation of hydrogen peroxide directly from water compares favorably with a number of other methods including electron beam, ultrasound, electrochemical and photochemical methods, and other chemical processes.

  18. Review of the methods to form hydrogen peroxide in electrical discharge plasma with liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Locke, Bruce R; Shih, Kai-Yuan [Department of Chemical and Biomedical Engineering, Florida State University, Tallahassee, FL 32310 (United States)

    2011-06-15

    This paper presents a review of the literature dealing with the formation of hydrogen peroxide from plasma processes. Energy yields for hydrogen peroxide generation by plasma from water span approximately three orders of magnitude from 4 x 10{sup -2} to 80 g kWh{sup -1}. A wide range of plasma processes from rf to pulsed, ac, and dc discharges directly in the liquid phase have similar energy yields and may thus be limited by radical quenching processes at the plasma-liquid interface. Reactor modification using discharges in bubbles and discharges over the liquid phase can provide modest improvements in energy yield over direct discharge in the liquid, but the interpretation is complicated by additional chemical reactions of gas phase components such as ozone and nitrogen oxides. The highest efficiency plasma process utilizes liquid water droplets that may enhance efficiency by sequestering hydrogen peroxide in the liquid and by suppressing decomposition reactions by radicals from the gas and at the interface. Kinetic simulations of water vapor reported in the literature suggest that plasma generation of hydrogen peroxide should approach 45% of the thermodynamics limit, and this fact coupled with experimental studies demonstrating improvements with the presence of the condensed liquid phase suggest that further improvements in energy yield may be possible. Plasma generation of hydrogen peroxide directly from water compares favorably with a number of other methods including electron beam, ultrasound, electrochemical and photochemical methods, and other chemical processes.

  19. An electrochemical method for determining hydrogen concentrations in metals and some applications

    Science.gov (United States)

    Danford, M. D.

    1983-01-01

    An electrochemical method was developed for the determination of hydrogen in metals using the EG&G-PARC Model 350A Corrosion Measurement Console. The method was applied to hydrogen uptake, both during electrolysis and electroplating, and to studies of hydrogen elimination and the effect of heat treatment on elimination times. Results from these studies are presented.

  20. Hydrogen charging/discharging system with liquid organic compounds: a lacunar oxide catalyst to hydrogenate the unsaturated organic compound

    International Nuclear Information System (INIS)

    Jalowiecki-Duhamel, L.; Carpentier, J.; Payen, E.; Heurtaux, F.

    2006-01-01

    Lacunar mixed oxides based on cerium nickel and aluminium or zirconium CeM 0.5 Ni x O y s (M = Zr or Al), able to store high quantities of hydrogen, have been analysed in the hydrogenation of toluene into methyl-cyclohexane (MCH). When these solids present very good toluene hydrogenation activity and selectivity towards MCH in presence of H 2 , in absence of gaseous hydrogen, the reactive hydrogen species stored in the solid can hydrogenate toluene into MCH. The hydrogenation activity under helium + toluene flow decreases as a function of time and becomes nil. The integration of the curve obtained allows to determine the extractable hydrogen content of the solid used, and a value of 1.2 wt % is obtained at 80 C on a CeAl 0.5 Ni 3 O y compound pre-treated in H 2 at 300 C. To optimise the system, different parameters have been analysed, such as the catalyst formulation, the metal content, the pre-reducing conditions as well as the reaction conditions under helium + toluene. (authors)

  1. Electrical resistivity of liquid noble metal alloys

    International Nuclear Information System (INIS)

    Anis Alam, M.; Tomak, M.

    1983-08-01

    Calculations of the dependence of the electrical resistivity in liquid Ag-Au, Cu-Ag, Cu-Au binary alloys on composition are reported. The structure of the binary alloy is described as a hard sphere system. A one-parameter local pseudopotential, which incorporates s-d hybridization effects phenomenologically, is employed in the resistivity calculation. A reasonable agreement with experimental trends is observed in cases where experimental information is available. (author)

  2. Liquid metal cooled blanket concept for NET

    International Nuclear Information System (INIS)

    Malang, S.; Casal, V.; Arheidt, K.; Fischer, U.; Link, W.; Rust, K.

    1986-01-01

    A blanket concept for NET using liquid lithium-lead both as breeder material and as coolant is described. The need for inboard breeding is avoided by using beryllium as neutron multiplier in the outboard blanket. Novel flow channel inserts are employed in all poloidal ducts to reduce the MHD pressure drop. The concept offers a simple mechanical design and a higher tritium breeding ratio compared to water- and gas-cooled blankets. (author)

  3. Data acquisition and quantitative analysis of stable hydrogen isotope in liquid and gas in the liquid phase catalytic exchange process

    International Nuclear Information System (INIS)

    Choi, H. J.; Lee, H. S.; Kim, K. R.; Cheong, H. S.; Ahn, D. H.; Lee, S. H.; Paek, S. W.; Kang, H. S.; Kim, J. G.

    2001-01-01

    A pilot plant for the Liquid Phase Catalytic Exchange process was built and has been operating to test the hydrophobic catalyst developed to remove the tritium generated at the CANDU nuclear power plants. The methods of quantitative analysis of hydrogen stable isotope were compared. Infrared spectroscopy was used for the liquid samples, and gas chromatography with hydrogen carrier gas showed the best result for gas samples. Also, a data acquisition system was developed to record the operation parameters. This record was very useful to investigate the causes of the system trip

  4. Nuclear quadrupole relaxation and viscosity in liquid metals

    International Nuclear Information System (INIS)

    Schirmacher, W.

    1976-01-01

    It is shown that the nuclear quadrupole relaxation rate due to the molecular motions in liquid metals is related to the shear and bulk viscosity and hence to the absorption coefficient of ultrasound. Application of the 'extended liquid phonon' model of Ortoleva and Nelkin - which is the third of a series of continued-fraction-approximations for the van Hove neutron scattering function - gives a relation to the self diffusion constant. The predictions of the theory concerning the temperature dependence are compared with quadrupole relaxation measurements of Riegel et al. and Kerlin et al. in liquid gallium. Agreement is found only with the data of Riegel et al. (orig.) [de

  5. Notch Effect on Tensile Deformation Behavior of 304L and 316L Steels in Liquid Helium and Hydrogen

    International Nuclear Information System (INIS)

    Shibata, K.; Fujii, H.

    2004-01-01

    Tensile tests of type 304L and 316L steels were carried out using round bar specimens with a notch in liquid helium, hydrogen, liquid nitrogen and at ambient temperature. The obtained tensile strengths were compared with the tensile strengths of smooth specimens. For smooth specimens, tensile strength increased with a decrease in temperature and the strengths in liquid helium and hydrogen show similar values in both steels. For notched specimen of 304L steel, tensile strength (including fracture strength) increased noticeably from ambient to liquid nitrogen temperature but showed a large decrease in liquid helium and hydrogen. In liquid hydrogen and helium, the tensile strength is a little lower in liquid hydrogen than in liquid helium and both strengths are lower than tensile strengths of smooth specimens. For notched specimen of 316L steel, an increase in tensile strength from ambient to liquid nitrogen temperature was not so large and a decrease from liquid nitrogen to liquid hydrogen was small. The tensile strengths in liquid helium and hydrogen were nearly same and higher than those of smooth specimens. Different behavior of serration was observed between liquid helium and hydrogen, and between 304L and 316L steels. The reasons for these differences were discussed using computer simulation

  6. Studies about interaction of hydrogen isotopes with metals and intermetallic compounds

    International Nuclear Information System (INIS)

    Vasut, F.; Anisoara, P.; Zamfirache, M.

    2003-01-01

    Hydrogen is a non-toxic but highly inflammable gas. Compared to other inflammable gases, its range of inflammability in air is much broader (4-74.5%) but it also vaporizes much more easily. Handling of hydrogen in form of hydrides enhances safety. The interaction of hydrogen with metals and intermetallic compounds is a major field within physical chemistry. Using hydride-forming metals and intermetallic compounds, for example, recovery, purification and storage of heavy isotopes in tritium containing system can solve many problems arising in the nuclear-fuel cycle. The paper presents the thermodynamics and the kinetics between hydrogen and metal or intermetallic compounds. (author)

  7. Applications of some microscopic, diffraction and absorption techniques to the study of metal--hydrogen systems

    International Nuclear Information System (INIS)

    Pick, M.A.

    1979-01-01

    Several experimental techniques were reviewed which are used to investigate metal hydrogen systems. The first technique is metallography and optical microscopy. This is a very old technique which was found to be very powerful in the case of metal hydrogen systems. A few examples of such work are shown and the results are discussed

  8. Structural crossover in a supercooled metallic liquid and the link to a liquid-to-liquid phase transition

    Energy Technology Data Exchange (ETDEWEB)

    Lan, S.; Ma, J. L.; Fan, J. [Department of Physics and Material Science, City University of Hong Kong 83 Tat Chee Ave., Kowloon (Hong Kong); Blodgett, M.; Kelton, K. F. [Department of Physics and Institute of Materials Science and Engineering, Washington University One Brookings Drive, St. Louis, Missouri 63130-4899 (United States); Wang, X.-L., E-mail: xlwang@cityu.edu.hk [Department of Physics and Material Science, City University of Hong Kong 83 Tat Chee Ave., Kowloon (Hong Kong); City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057 (China)

    2016-05-23

    Time-resolved synchrotron measurements were carried out to capture the structure evolution of an electrostatically levitated metallic-glass-forming liquid during free cooling. The experimental data shows a crossover in the liquid structure at ∼1000 K, about 115 K below the melting temperature and 150 K above the crystallization temperature. The structure change is characterized by a dramatic growth in the extended-range order below the crossover temperature. Molecular dynamics simulations have identified that the growth of the extended-range order was due to an increased correlation between solute atoms. These results provide structural evidence for a liquid-to-liquid-phase-transition in the supercooled metallic liquid.

  9. The use of infrared absorption to determine density of liquid hydrogen.

    Science.gov (United States)

    Unland, H. D.; Timmerhaus, K. D.; Kropschot, R. H.

    1972-01-01

    Experimental evaluation of the use of infrared absorption for determining the density of liquid hydrogen, and discussion of the feasibility of an airborne densitometer based on this concept. The results indicate that infrared absorption of liquid hydrogen is highly sensitive to the density of hydrogen, and, under the operating limitations of the equipment and experimental techniques used, the determined values proved to be repeatable to an accuracy of 2.7%. The desiderata and limitations of an in-flight density-determining device are outlined, and some of the feasibility problems are defined.

  10. The self limiting effect of hydrogen cluster in gas jet under liquid nitrogen temperature

    International Nuclear Information System (INIS)

    Han Jifeng; Yang Chaowen; Miao Jingwei; Fu Pengtao; Luo Xiaobing; Shi Miangong

    2010-01-01

    The generation of hydrogen clusters in gas jet is tested using the Rayleigh scattering method under liquid nitrogen temperature of 79 K. The self limiting effect of hydrogen cluster is studied and it is found that the cluster formation is greatly affected by the number of expanded molecules. The well designed liquid nitrogen cold trap ensured that the hydrogen cluster would keep maximum size for maximum 15 ms during one gas jet. The scattered light intensity exhibits a power scaling on the backing pressure ranging from 5 to 48 bar with the power value of 4.1.

  11. Standard practice for evaluation of hydrogen uptake, permeation, and transport in metals by an electrochemical technique

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1997-01-01

    1.1 This practice gives a procedure for the evaluation of hydrogen uptake, permeation, and transport in metals using an electrochemical technique which was developed by Devanathan and Stachurski. While this practice is primarily intended for laboratory use, such measurements have been conducted in field or plant applications. Therefore, with proper adaptations, this practice can also be applied to such situations. 1.2 This practice describes calculation of an effective diffusivity of hydrogen atoms in a metal and for distinguishing reversible and irreversible trapping. 1.3 This practice specifies the method for evaluating hydrogen uptake in metals based on the steady-state hydrogen flux. 1.4 This practice gives guidance on preparation of specimens, control and monitoring of the environmental variables, test procedures, and possible analyses of results. 1.5 This practice can be applied in principle to all metals and alloys which have a high solubility for hydrogen, and for which the hydrogen permeation is ...

  12. NATO International Symposium on the Electronic Structure and Properties of Hydrogen in Metals

    CERN Document Server

    Satterthwaite, C

    1983-01-01

    Hydrogen is the smallest impurity atom that can be implanted in a metallic host. Its small mass and strong interaction with the host electrons and nuclei are responsible for many anomalous and interesting solid state effects. In addition, hydrogen in metals gives rise to a number of technological problems such as hydrogen embrittlement, hydrogen storage, radiation hardening, first wall problems associated with nuclear fusion reactors, and degradation of the fuel cladding in fission reactors. Both the fundamental effects and applied problems have stimulated a great deal of inter­ est in the study of metal hydrogen systems in recent years. This is evident from a growing list of publications as well as several international conferences held in this field during the past decade. It is clear that a fundamental understanding of these problems re­ quires a firm knowledge of the basic interactions between hydrogen, host metal atoms, intrinsic lattice defects and electrons. This understanding is made particularly di...

  13. Performance Tests of a Permeation Sensor for Test Blanket Modules Using Liquid Metal

    International Nuclear Information System (INIS)

    Choi, B. G.; Lee, D. W.; Lee, E. H.; Yoon, J. S.; Kim, S. K.; Shin, K. I.; Jin, H. G.

    2013-01-01

    The tritium extraction from a breeder is one of the key technologies and its methods have been investigated. For developing the tritium extraction methods and evaluating the amount of tritium in the system, a reliable and correct sensor is required to measure the hydrogen concentration in liquid metal breeder. There are several researches for developing the sensors in the ITER participants and especially, EU has developed the permeation sensors trying to selecting materials with low Serviette's constant (solubility) and high hydrogen diffusivity coefficient. However, EU's response time is still too long time about tens of minutes to measure the tritium concentration in the online system. We have been performing the preliminary tests with designed and fabricated sensors to solve the late response of sensor. However, we could not continue the tests because of the membrane's oxidation (pure Fe) and the difficulty of welding nonferrous metals. In present study, a permeation sensor made of vacuum flanges with a porous plate inside is proposed not only to eliminate the difficulty of the fabrication but to optimize the performance of sensor. The permeation sensor to measure the hydrogen isotopes in liquid metal breeder has been proposed and evaluated to overcome the limitation of a long response time for various shapes and materials. We found that the previous sensors have limitation; the oxidation problems (pure Fe) and the difficulty in welding (nonferrous metals). Therefore we proposed a permeation sensor with the vacuum flanges filled with porous disks to eliminate the problems. By using the CF flanges, the problem caused by welding is removed. But the permeable response time of sensors took a long time to reach the pressure equivalent

  14. Designing Kitaev Spin Liquids in Metal-Organic Frameworks

    Science.gov (United States)

    Yamada, Masahiko G.; Fujita, Hiroyuki; Oshikawa, Masaki

    2017-08-01

    Kitaev's honeycomb lattice spin model is a remarkable exactly solvable model, which has a particular type of spin liquid (Kitaev spin liquid) as the ground state. Although its possible realization in iridates and α -RuCl3 has been vigorously discussed recently, these materials have substantial non-Kitaev direct exchange interactions and do not have a spin liquid ground state. We propose metal-organic frameworks (MOFs) with Ru3 + (or Os3 + ), forming the honeycomb lattice as promising candidates for a more ideal realization of Kitaev-type spin models, where the direct exchange interaction is strongly suppressed. The great flexibility of MOFs allows generalization to other three-dimensional lattices for the potential realization of a variety of spin liquids, such as a Weyl spin liquid.

  15. Modeling of hydrogen isotopes separation in a metal hydride bed

    International Nuclear Information System (INIS)

    Charton, S.; Corriou, J.P.; Schweich, D.

    1999-01-01

    A predictive model for hydrogen isotopes separation in a non-isothermal bed of unsupported palladium hydride particles is derived. It accounts for the non-linear adsorption-dissociation equilibrium, hydrodynamic dispersion, pressure drop, mass transfer kinetics, heat of sorption and heat losses at the bed wall. Using parameters from the literature or estimated with classical correlations, the model gives simulated curves in agreement with previously published experiments without any parameter fit. The non-isothermal behavior is shown to be responsible for drastic changes of the mass transfer rate which is controlled by diffusion in the solid-phase lattice. For a feed at 300 K and atmospheric pressure, the endothermic hydride-to-deuteride exchange is kinetically controlled, whereas the reverse exothermic exchange is nearly at equilibrium. Finally, a simple and efficient thermodynamic model for the dissociative equilibrium between a metal and a diatomic gas is proposed. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  16. Neutron spectroscopy of fast hydrogen diffusion in BCC transition metals

    International Nuclear Information System (INIS)

    Richter, D.; Lottner, V.

    1979-01-01

    Quasielastic neutron scattering reveals microscopic details of both the time and space development of the H-diffusion process on an atomic scale. After outlining the method on the example of PdH/sub x/, new results on the jump geometry in bcc metals are surveyed. In particular, the anomalous diffusion behavior of H in Nb, Ta, and V at elevated temperature is emphasized, where correlated jump processes are important. The influence of impurities on the H-diffusion process is demonstrated by experiments performed on NbH/sub x/ doped with nitrogen impurities, which act as trapping centers for the diffusing hydrogen. The results are discussed in terms of a two-state random walk model which includes multiple trapping and detrapping processes. The concentration and temperature dependence of the capture and escape rates of traps are obtained

  17. Electron-doping by hydrogen in transition-metal dichalcogenides

    Science.gov (United States)

    Oh, Sehoon; Im, Seongil; Choi, Hyoung Joon

    Using first-principles calculations, we investigate the atomic and electronic structures of 2H-phase transition-metal dichalcogenides (TMDC), 2H-MX2, with and without defects, where M is Mo or W and X is S, Se or Te. We find that doping of atomic hydrogen on 2H-MX2 induces electron doping in the conduction band. To understand the mechanism of this electron doping, we analyze the electronic structures with and without impurities. We also calculate the diffusion energy barrier to discuss the spatial stability of the doping. Based on these results, we suggest a possible way to fabricate elaborately-patterned circuits by modulating the carrier type of 2H-MoTe2. We also discuss possible applications of this doping in designing nano-devices. This work was supported by NRF of Korea (Grant No. 2011-0018306) and KISTI supercomputing center (Project No. KSC-2016-C3-0052).

  18. Light Metal Decorated Graphdiyne (GDY) Nanosheets for Reversible Hydrogen Storage.

    Science.gov (United States)

    Panigrahi, P; Dhinakaran, A K; Naqvi, S R; Rao, Sankara Gollu; Ahuja, Rajeev; Hussain, Tanveer

    2018-05-29

    The sensitive nature of molecular hydrogen (H2) interaction with the surfaces of pristine and functionalized nanostructures, especially two-dimensional materials (2D) has been a subject of debate for a while now. An accurate approximation of H2 adsorption mechanism has a vital significance for the specific fields like H2 storage applications. Owing to the importance of this issue, we have performed a comprehensive DFT study by means of several different approximations to investigate the structural, electronic, charge transfer and energy storage properties of pristine and functionalized graphdiyne (GDY) nano sheets. The dopants considered here include light-metals Li, Na, K, Ca, Sc and Ti, which make uniform distribution over GDY even at high doping concentration due to their strong binding and charge transfer mechanism. Upon 11% of metal functionalization, GDY changes into metallic state from being a small band gap semiconductor. Such situations turn the dopants to a partial positive state, which is favorable for adsorption of H2 molecules. The adsorption mechanism of H2 on GDY has been studied and compared by different methods like GGA, vdW-DF and DFT-D3 functionals. It has been established that each functionalized systems anchor multiple H2 molecules with adsorption energies that falls into a suitable range regardless of the functional used for approximations. A significantly high H2 storage capacity would guarantee that light metal-doped GDY nano sheets could serve the purpose of an efficient and reversible H2 storage material. © 2018 IOP Publishing Ltd.

  19. The Oscillatory Nature of Rotating Convection in Liquid Metal

    Science.gov (United States)

    Aurnou, J. M.; Bertin, V. L.; Grannan, A. M.

    2016-12-01

    Earth's magnetic field is assumed to be generated by fluid motions in its liquid metal core. In this fluid, the heat diffuses significantly more than momentum and thus, the ratio of these two diffusivities, the Prandtl number Pr=ν/Κ, is well below unity. The convective flow dynamics of liquid metal is very different from Pr ≈ 1 fluids like water and those used in current dynamo simulations. In order to characterize rapidly rotating thermal convection in low Pr number fluids, we have performed laboratory experiments in a cylinder using liquid gallium (Pr ≈ 0.023) as the working fluid. The Ekman number, which characterizes the effect of rotation, varies from E = 4 10-5 to 4 10-6 and the dimensionless buoyancy forcing (Rayleigh number, Ra) varies from Ra =3 105 to 2 107. Using heat transfer measurements (Nusselt number, Nu) as well as temperature measurements within the fluid, we characterize the different styles of low Pr rotating convective flow. The convection threshold is first overcome in the form of a container scale inertial oscillatory mode. At stronger forcing, wall-localized modes are identified for the first time in liquid metal laboratory experiments. These wall modes coexist with the bulk inertial oscillatory modes. When the strengh of the buoyancy increases, the bulk flow becomes turbulent while the wall modes remain. Our results imply that rotating convective flows in liquid metals do not develop in the form of quasi-steady columns, as in Pr ≈ 1 dynamo models, but in the form of oscillatory motions. Therefore, the flows that drive thermally-driven dynamo action in low Pr geophysical and astrophysical fluids can differ substantively than those occuring in current-day Pr ≈ 1 numerical models. In addition, our results suggest that relatively low wavenumber, wall-attached modes may be dynamically important in rapidly-rotating convection in liquid metals.

  20. Design and integration of a hydrogen storage on metallic hydrides

    International Nuclear Information System (INIS)

    Botzung, M.

    2008-01-01

    This work presents a hydrogen storage system using metal hydrides for a Combined Heat and Power (CHP) system. Hydride storage technology has been chosen due to project specifications: high volumetric capacity, low pressures (≤ 3.5 bar) and low temperatures (≤ 75 C: fuel cell temperature). During absorption, heat from hydride generation is dissipated by fluid circulation. An integrated plate-fin type heat exchanger has been designed to obtain good compactness and to reach high absorption/desorption rates. At first, the storage system has been tested in accordance with project specifications (absorption 3.5 bar, desorption 1.5 bar). Then, the hydrogen charge/discharge times have been decreased to reach system limits. System design has been used to simulate thermal and mass comportment of the storage tank. The model is based on the software Fluent. We take in consideration heat and mass transfers in the porous media during absorption/desorption. The hydride thermal and mass behaviour has been integrated in the software. The heat and mass transfers experimentally obtained have been compared to results calculated by the model. The influence of experimental and numerical parameters on the model behaviour has also been explored. (author) [fr

  1. Cellular automaton model for hydrogen transport dynamics through metallic surface

    International Nuclear Information System (INIS)

    Shimura, K.; Yamaguchi, K.; Terai, T.; Yamawaki, M.

    2002-01-01

    Hydrogen re-emission and re-combination at the surface of first wall materials are a crucial issue for the understanding of the fuel recycling and for the tritium inventory in plasma facing materials. It is know to be difficult to model the transient behaviour of those processes due to their complex time-transient nature. However, cellular automata (CA) are powerful tools to model such complex systems because of their nature of discreteness in both dependent and independent variables. Then the system can be represented by the fully local interactions between cells. For that reason, complex physical and chemical systems can be described by fairly simple manner. In this study, the kinetics of desorption of adsorbed hydrogen from an ideal metallic surface is modelled in CA. Thermal desorption is simulated with this model and the comparison with the theory of rate processes is performed to identify the validity of this model. The overall results show that this model is reasonable to express the desorption kinetics

  2. The equilibrium hydrogen pressure-temperature diagram for the liquid sodium-hydrogen-oxygen system

    International Nuclear Information System (INIS)

    Knights, C.F.; Whittingham, A.C.

    1982-01-01

    The underlying equilibria in the sodium-hydrogen-oxygen system are presented in the form of a completmentary hydrogen equilibrium pressure-temperature diagram, constructed by using published data and supplemented by experimental measurements of hydrogen equilibrium pressures over condensed phases in the system. Possible applications of the equilibrium pressure-temperature phase diagram limitations regarding its use are outlined

  3. Collective Excitations in Liquid Hydrogen Observed by Coherent Neutron Scattering

    DEFF Research Database (Denmark)

    da Costa Carneiro, Kim; Nielsen, M.; McTague, J. P.

    1973-01-01

    Coherent scattering of neutrons by liquid parahydrogen shows the existence of well-defined collective excitations in this liquid. Qualitative similarity with the scattering from liquid helium is found. Furthermore, in the range of observed wave vectors, 0.7 Å-1 ≤κ≤3.1 Å-1, extending from the firs...

  4. New vistas in the determination of hydrogen in aerospace engine metal alloys

    Science.gov (United States)

    Danford, M. D.

    1986-01-01

    The application of diffusion theory to the analysis of hydrogen desorption data has been studied. From these analyses, important information concerning hydrogen solubilities and the nature of the hydrogen distributions in the metal has been obtained. Two nickel base alloys, Rene' 41 and Waspaloy, and one ferrous alloy, 4340 steel, were studied in this work. For the nickel base alloys, it was found that the hydrogen distributions after electrolytic charging conformed closely to those which would be predicted by diffusion theory. The hydrogen distributions in electrolytically charged 4340 steel, on the other hand, were essentially uniform in nature, which would not be predicted by diffusion theory. Finally, it has been found that the hydrogen desorption is completely explained by the nature of the hydrogen distribution in the metal, and that the 'fast' hydrogen is not due to surface and subsurface hydride formation, as was originally proposed.

  5. Adsorption of hydrogen isotopes by metals in non-equilibrium conditions

    International Nuclear Information System (INIS)

    Livshits, A.I.; Notkin, M.E.; Pustovojt, Yu.M.

    1982-01-01

    To study the interaction of thermonuclear plasma and additions with metallic walls, nonequilibrium system of thermal atomary hydrogen - ''cold'' (300-1100 K) metal is experimentally investigated. Atomary hydrogen was feeded to samples of Ni and Pd in the shape of atomic beam, coming into vacuum from high-frequency gaseous discharge. It is shown that hydrogen solubility under nonequilibrium conditions increases with surface passivation (contamination); in this case it surpasses equilibrium solubility by value orders. Nickel and iron dissolve more hydrogen than palladium at a certain state of surface ( passivation) and gas (atomary hydrogen). The sign of the temperature dependence of hydrogen solubility in passivated N 1 and Fe changes when alterating molecular hydrogen by atomary hydrogen

  6. Hydrogen storage in Pd nanocrystals covered with a metal-organic framework

    Science.gov (United States)

    Li, Guangqin; Kobayashi, Hirokazu; Taylor, Jared M.; Ikeda, Ryuichi; Kubota, Yoshiki; Kato, Kenichi; Takata, Masaki; Yamamoto, Tomokazu; Toh, Shoichi; Matsumura, Syo; Kitagawa, Hiroshi

    2014-08-01

    Hydrogen is an essential component in many industrial processes. As a result of the recent increase in the development of shale gas, steam reforming of shale gas has received considerable attention as a major source of H2, and the more efficient use of hydrogen is strongly demanded. Palladium is well known as a hydrogen-storage metal and an effective catalyst for reactions related to hydrogen in a variety of industrial processes. Here, we present remarkably enhanced capacity and speed of hydrogen storage in Pd nanocrystals covered with the metal-organic framework (MOF) HKUST-1 (copper(II) 1,3,5-benzenetricarboxylate). The Pd nanocrystals covered with the MOF have twice the storage capacity of the bare Pd nanocrystals. The significantly enhanced hydrogen storage capacity was confirmed by hydrogen pressure-composition isotherms and solid-state deuterium nuclear magnetic resonance measurements. The speed of hydrogen absorption in the Pd nanocrystals is also enhanced by the MOF coating.

  7. Metal-support interactions in electrocatalysis: Hydrogen effects on electron and hole transport at metal-support contacts

    International Nuclear Information System (INIS)

    Heller, A.

    1986-01-01

    This paper discusses the effects of hydrogen on electron and hole transport at metal support contacts during electrocatalysis. When hydrogen dissolves in high work function metals such as Pt, Rh or Ru the contact forms between the semiconductor and the hydrogenated metal, which has a work function that is lower than that of the pure metal. Thus by changing the gaseous atmosphere that envelopes metal-substrate contacts, it is possible to reversibly change their diode characteristics. In some cases, such as Pt on n-TiO/sub 2/, Rh on n-TiO/sub 2/ and Ru on n-TiO/sub 2/, it is even possible to reversibly convert Schottky diodes into ohmic contacts by changing the atmosphere from air to hydrogen. In contacts between hydrogen dissolving group VIII metals and semiconducting substrates, one can test for interfacial reaction of the catalysts and the substrate by examining the electrical characteristics of the contacts in air (oxygen) and in hydrogen. In the absence of interfacial reaction, large hydrogen induced variation in the barrier heights is observed and the hydrogenated contacts, approach ideality (i.e. their non-ideality factor is close to unity). When a group VIII metal and a substrate do react, the reaction often produces a phase that blocks hydrogen transport to the interface between the substrate and the reaction product. In this case the hydrogen effect is reduced or absent. Furthermore, because such reaction often introduces defects into the surface of the semiconductor, the contacts have non-ideal diode characteristics

  8. Manufacturing processes of cellular metals. Part I. Liquid route processes

    International Nuclear Information System (INIS)

    Fernandez, P.; Cruz, L. J.; Coleto, J.

    2008-01-01

    With its interesting and particular characteristics, cellular metals are taking part of the great family of new materials. They can have open or closed porosity. At the present time, the major challenge for the materials researchers is based in the manufacturing techniques improvement in order to obtain reproducible and reliable cellular metals with quality. In the present paper, the different production methods to manufacture cellular metals by liquid route are reviewed; making a short description about the main parameters involved and the advantages and drawbacks in each of them. (Author) 106 refs

  9. Long range order and hydrogen bonding in liquid methanol: A Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Shilov, I.Y.; Rode, B.M. [Department of Theoretical Chemistry, Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 52a, A-6020 Innsbruck (Austria); Durov, V.A. [Department of Physical Chemistry, Faculty of Chemistry, Lomonosov Moscow State University, Moscow (Russian Federation)

    1999-02-01

    A Monte Carlo simulation of liquid methanol was performed in NVT ensemble at 298 K using a cubic simulation box containing 500 molecules. Long-range correlations in the liquid are discussed on the basis of site-site radial distribution functions. Hydrogen bonding and topological structure of the methanol aggregates were evaluated in detail, namely the number of linked molecules, formation of branches and cyclic structures. The necessity of larger simulation boxes for a full structural description and thermodynamic characterization of hydrogen-bonded liquids is clearly established by the results. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. Combustion characteristics of nanoaluminum, liquid water, and hydrogen peroxide mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Sabourin, J.L.; Yetter, R.A. [The Pennsylvania State University, Department of Mechanical and Nuclear Engineering, University Park, PA 16801 (United States); Risha, G.A. [The Pennsylvania State University, Division of Business and Engineering, Altoona, PA 16601 (United States); Son, S.F. [Purdue University, School of Mechanical Engineering, West Lafayette, IN 47907 (United States); Tappan, B.C. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2008-08-15

    An experimental investigation of the combustion characteristics of nanoaluminum (nAl), liquid water (H{sub 2}O{sub (l)}), and hydrogen peroxide (H{sub 2}O{sub 2}) mixtures has been conducted. Linear and mass-burning rates as functions of pressure, equivalence ratio ({phi}), and concentration of H{sub 2}O{sub 2} in H{sub 2}O{sub (l)} oxidizing solution are reported. Steady-state burning rates were obtained at room temperature using a windowed pressure vessel over an initial pressure range of 0.24 to 12.4 MPa in argon, using average nAl particle diameters of 38 nm, {phi} from 0.5 to 1.3, and H{sub 2}O{sub 2} concentrations between 0 and 32% by mass. At a nominal pressure of 3.65 MPa, under stoichiometric conditions, mass-burning rates per unit area ranged between 6.93 g/cm{sup 2} s (0% H{sub 2}O{sub 2}) and 37.04 g/cm{sup 2} s (32% H{sub 2}O{sub 2}), which corresponded to linear burning rates of 9.58 and 58.2 cm/s, respectively. Burning rate pressure exponents of 0.44 and 0.38 were found for stoichiometric mixtures at room temperature containing 10 and 25% H{sub 2}O{sub 2}, respectively, up to 5 MPa. Burning rates are reduced above {proportional_to}5 MPa due to the pressurization of interstitial spaces of the packed reactant mixture with argon gas, diluting the fuel and oxidizer mixture. Mass burning rates were not measured above {proportional_to}32% H{sub 2}O{sub 2} due to an anomalous burning phenomena, which caused overpressurization within the quartz sample holder, leading to tube rupture. High-speed imaging displayed fingering or jetting ahead of the normal flame front. Localized pressure measurements were taken along the sample length, determining that the combustion process proceeded as a normal deflagration prior to tube rupture, without significant pressure buildup within the tube. In addition to burning rates, chemical efficiencies of the combustion reaction were determined to be within approximately 10% of the theoretical maximum under all conditions

  11. Generation and characterization of gas bubbles in liquid metals

    International Nuclear Information System (INIS)

    Eckert, S.; Gerbeth, G.; Witke, W.

    1996-01-01

    There is an ongoing research performed in the RCR on local transport phenomena in turbulent liquid metal (LM) duct flows exposed to external magnetic fields. In this context so-called MHD flow phenomena can be observed, which are unknown in usual hydraulic engineering. The field of interest covers also the influence of magnetic fields on the behaviour of liquid metal - gas mixtures. Profound knowledge on these LMMHD two-phase flow plays an important role in a variety of technological applications, in particular, in the design of Liquid-Metal MHD generators or for several metallurgical processes employing gas-stirred reactors. However, the highly empirical nature of two-phase flow analysis gives little hope for the prediction of MHD two-phase flows without extensive experimental data. A summary is given about the authors research activities focussing on two directions: (a) Momentum transfer between gas and liquid metal in a bubbly flow regime to investigate the influence of the external magnetic field on the velocity slip ration S (b) Peculiarities of the MHD turbulence to use small gas bubbles as local tracers in order to study the turbulent mass transfer

  12. Structure of liquid alkali metals as electron-ion plasmas

    International Nuclear Information System (INIS)

    Chaturvedi, D.K.; Senatore, G.; Tosi, M.P.

    1980-08-01

    The static structure factor of liquid alkali metals near freezing, and its dependence on temperature and pressure, are evaluated in an electron-ion plasma model from an accurate theoretical determination of the structure factor of the one-component classical plasma and electron-screening theory. Very good agreement is obtained with the available experimental data. (author)

  13. Liquid metal-based reconfigurable and stretchable photolithography

    International Nuclear Information System (INIS)

    Kim, Daeyoung; Yoo, Jun Hyeon; Lee, Jeong-Bong

    2016-01-01

    Conventional ultraviolet (UV) lithography typically uses a photomask made of a fused silica plate covered with a layer of UV opaque material such as chromium. The photomask has passive binary patterns of UV opaque and UV transparent regions and the pattern is unalterable. We report a novel real-time dynamically reconfigurable photomask technology using a liquid metal (as a UV opaque material) filled in polydimethylsiloxane (PDMS, as a UV transparent material) microfluidic channels. We found that the gallium-based liquid metal (e.g. Galinstan ® ) is opaque in broad spectrum of light in the wavelength from 325 nm to 850 nm while the PDMS is highly transparent in this wide range of spectrum. We made both bright field and dark field microfluidic photomasks and transferred various patterns onto a positive photoresist. A 7-segment display microfluidic channel photomask was also fabricated and decimal numerals (from ‘0’ to ‘9’) were patterned with one photomask by dynamically reconfiguring decimal numeral shapes with on-demand injection and withdrawal of the liquid metal in specific segment microfluidic channels in the photomask. In addition, utilizing mechanical flexibility of the PDMS and the liquid metal, reconfiguration of the patterns in a microfluidic photomask under stretching was successfully tested. (paper)

  14. Continuous process for selective metal extraction with an ionic liquid

    NARCIS (Netherlands)

    Parmentier, D.; Paradis, S.; Metz, S.J.; Wiedmer, S.K.; Kroon, M.C.

    2016-01-01

    This work describes for the first time a continuous process for selective metal extraction with an ionic liquid (IL) at room temperature. The hydrophobic fatty acid based IL tetraoctylphosphonium oleate ([P8888][oleate]) was specifically chosen for its low viscosity and high selectivity towards

  15. Structural properties of low-density liquid alkali metals

    Indian Academy of Sciences (India)

    The static structure factors of liquid alkali metals have been modelled at temperatures close to their melting points and a few higher temperatures using the reverse Monte Carlo (RMC) method. The positions of 5000 atoms in a box, with full periodicity, were altered until the experimental diffraction data of the structure factor ...

  16. Determination of liquid metal density using X-radiography

    International Nuclear Information System (INIS)

    Mel'nik, B.A.

    1978-01-01

    A method for measuring molten metal densities based on the determination of the critical angle of complete external X-ray reflection angle is proposed. A good agreement between the experimental and reported data is exemplified by density measurements of liquid Ga, In and Hg at different temperatures. The theoretical method accuracy is 0.2%

  17. Fuel transfer manipulator for liquid metal nuclear reactors

    International Nuclear Information System (INIS)

    Sturges, R.H.

    1983-01-01

    A manipulator for transferring fuel assemblies between inclined fuel chutes of a liquid metal nuclear reactor installation. Hoisting means are mounted on a mount supported by beams pivotably attached by pins to the mount and to the floor in such a manner that pivoting of the beams causes movement and tilting of a hoist tube between positions of alignment with the inclined chutes. (author)

  18. Graphite-based extinguishants for liquid metal fires

    International Nuclear Information System (INIS)

    Simpson, J.M.; Gardener, N.J.L.

    1987-01-01

    Effective extinguishants for liquid alkali metal fires must be provided for all LMFBRs. Traditional sodium salt based extinguishants have disadvantages. An intercalation compound of graphite was identified as a possible alternative. Following successful tests on fires of up to 25 m 2 area the graphite based extinguishant has been introduced by the UKAEA at Dounreay. (author)

  19. Liquid Metal Oscillation and Arc Behaviour during Welding

    NARCIS (Netherlands)

    Yudodibroto, B.Y.B.

    2010-01-01

    The purpose of this research is to obtain insight into the oscillation behaviour of the liquid metal and the arc behaviour during GMA welding. Observations of the weld pool and the arc were undertaken by visual means using a high-speed video and by analysis of the voltage. To deal with the complex

  20. Hydrogen storage evaluation based on investigations of the catalytic properties of metal/metal oxides in electrospun carbon fibers

    Energy Technology Data Exchange (ETDEWEB)

    Im, Ji Sun; Lee, Young-Seak [Department of Fine Chemical Engineering and Chemistry, Chungnam National University, Daejeon 305-764 (Korea); Park, Soo-Jin [Department of Chemistry, Inha University, Incheon 402-751 (Korea); Kim, Taejin [Core Technology Research Center for Fuel Cell, Jeollabuk-do 561-844 (Korea)

    2009-05-15

    In order to investigate the catalytic capacity of metals and metal oxides based on electrospun carbon fibers for improving hydrogen storage, electrospinning and heat treatments were carried out to obtain metal/metal oxide-embedded carbon fibers. Although the fibers were treated with the same activation procedure, they had different pore structures, due to the nature of the metal oxide. When comparing the catalytic capacity of metal and metal oxide, metal exhibits better performance as a catalyst for the improvement of hydrogen storage, when considering the hydrogen storage system. When a metal oxide with an m.p. lower than the temperature of heat treatment was used, the metal oxide was changed to metal during the heat treatment, developing a micropore structure. The activation process produced a high specific surface area of up to 2900 m{sup 2}/g and a pore volume of up to 2.5 cc/g. The amount of hydrogen adsorption reached approximately 3 wt% at 100 bar and room temperature. (author)

  1. Application of hydrogen isotopes and metal hydrides in future energy source

    Energy Technology Data Exchange (ETDEWEB)

    Guoqiang, Jiang [Sichuan Inst. of Materials and Technology, Chengdu, SC (China)

    1994-12-01

    The probable application of hydrogen isotopes and metal hydrides to future energy source is reviewed. Starting from existing state of China`s energy source, the importance for developing hydrogen energy and fusion energy is explained. It is suggested that the application investigation of hydrogen energy and hydrogen storage materials should be spurred and encouraged; keeping track of the development on tritium technology for fusion reactor is stressed.

  2. Application of hydrogen isotopes and metal hydrides in future energy source

    International Nuclear Information System (INIS)

    Jiang Guoqiang

    1994-12-01

    The probable application of hydrogen isotopes and metal hydrides to future energy source is reviewed. Starting from existing state of China's energy source, the importance for developing hydrogen energy and fusion energy is explained. It is suggested that the application investigation of hydrogen energy and hydrogen storage materials should be spurred and encouraged; keeping track of the development on tritium technology for fusion reactor is stressed

  3. Hydrogen and helium recycling from stirred liquid lithium under steady state plasma bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Hirooka, Yoshi, E-mail: hirooka.yoshihiko@nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); The Graduate School for Advanced Studies, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Zhou, Haishan [The Graduate School for Advanced Studies, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Ono, Masa [Princeton Plasma Physics Laboratory, PO Box 451, Princeton, NJ 08543 (United States)

    2014-12-15

    For improved core performance via edge plasma-wall boundary control, solid and liquid lithium has been used as a plasma-facing material in a number of confinement experiments over the past several decades. Unfortunately, it is unavoidable that lithium is saturated in the surface region with implanted hydrogenic species as well as oxygen-containing impurities. For steady state operation, a flowing liquid lithium divertor with forced convection would probably be required. In the present work, the effects of liquid stirring to simulate forced convection have been investigated on the behavior of hydrogen and helium recycling from molten lithium at temperatures up to ∼350 °C. Data indicate that liquid stirring reactivates hydrogen pumping via surface de-saturation and/or uncovering impurity films, but can also induce helium release via surface temperature change.

  4. Thermal design study of a liquid hydrogen-cooled cold-neutron source

    International Nuclear Information System (INIS)

    Quach, D.; Aldredge, R.C.; Liu, H.B.; Richards, W.J.

    2007-01-01

    The use of both liquid hydrogen as a moderator and polycrystalline beryllium as a filter to enhance cold neutron flux at the UC Davis McClellan Nuclear Radiation Center has been studied. Although, more work is needed before an actual cold neutron source can be designed and built, the purpose of this preliminary study is to investigate the effects of liquid hydrogen and the thickness of a beryllium filter on the cold neutron flux generated. Liquid hydrogen is kept at 20 K, while the temperature of beryllium is assumed to be 77 K in this study. Results from Monte Carlo simulations show that adding a liquid hydrogen vessel around the beam tube can increase cold neutron flux by more than an order of magnitude. As the thickness of the liquid hydrogen layer increases up to about half an inch, the flux of cold neutrons also increases. Increasing the layer thickness to more than half an inch gives no significant enhancement of cold neutron flux. Although, the simulations show that the cold neutron flux is almost independent of the thickness of beryllium at 77 K, the fraction of cold neutrons does drop along the beam tube. This may be due to the fact that the beam tube is not shielded for neutrons coming directly from the reactor core. Further design studies are necessary for to achieve complete filtering of undesired neutrons. A simple comparison analysis based on heat transfer due to neutron scattering and gamma-ray heating shows that the beryllium filter has a larger rate of change of temperature and its temperature is higher. As a result heat will be transferred from beryllium to liquid hydrogen, so that keeping liquid hydrogen at the desired temperature will be the most important step in the cooling process

  5. Discovery of Novel Complex Metal Hydrides for Hydrogen Storage through Molecular Modeling and Combinatorial Methods

    Energy Technology Data Exchange (ETDEWEB)

    Lesch, David A; Adriaan Sachtler, J.W. J.; Low, John J; Jensen, Craig M; Ozolins, Vidvuds; Siegel, Don; Harmon, Laurel

    2011-02-14

    order to exploit the tremendous gravimetric capacity of LiBH4. A number of LiNH2 LiBH4 transition metal (TM) systems were investigated for the following reasons. No additional leads were discovered in this system. Another major project activity was the assembly of a high throughput synthesis system. The automated synthesizer was set up in a glovebox and was capable of handling liquids and powders and carrying out sealed block syntheses up to 250 °C. Unfortunately, the synthesizer could not handle the delivery of the fine powders required fro hydrogen storage applications. Although the powder delivery system was overhauled and redesigned several times, this problem was never remedied.

  6. Chemical bonding of hydrogen molecules to transition metal complexes

    International Nuclear Information System (INIS)

    Kubas, G.J.

    1990-01-01

    The complex W(CO) 3 (PR 3 ) 2 (H 2 ) (CO = carbonyl; PR 3 = organophosphine) was prepared and was found to be a stable crystalline solid under ambient conditions from which the hydrogen can be reversibly removed in vacuum or under an inert atmosphere. The weakly bonded H 2 exchanges easily with D 2 . This complex represents the first stable compound containing intermolecular interaction of a sigma-bond (H-H) with a metal. The primary interaction is reported to be donation of electron density from the H 2 bonding electron pair to a vacant metal d-orbital. A series of complexes of molybdenum of the type Mo(CO)(H 2 )(R 2 PCH 2 CH 2 PR 2 ) 2 were prepared by varying the organophosphine substitutent to demonstrate that it is possible to bond either dihydrogen or dihydride by adjusting the electron-donating properties of the co-ligands. Results of infrared and NMR spectroscopic studies are reported. 20 refs., 5 fig

  7. Electronic specific heats in metal--hydrogen systems

    International Nuclear Information System (INIS)

    Flotow, H.E.

    1979-01-01

    The electronic specific heats of metals and metal--hydrogen systems can in many cases be evaluated from the measured specific heats at constant pressure, C/sub p/, in the temperature range 1 to 10 K. For the simplest case, C/sub p/ = γT + βT 3 , where γT represents the specific heat contribution associated with the conduction electrons, and βT 3 represents lattice specific heat contribution. The electronic specific heat coefficient, γ, is important because it is proportional to electron density of states at the Fermi surface. A short description of a low temperature calorimetric cryostat employing a 3 He/ 4 He dilution refrigeration is given. Various considerations and complications encountered in the evaluation of γ from specific heat data are discussed. Finally, the experimental values of γ for the V--Cr--H system and for the Lu--H system are summarized and the variations of γ as function of alloy composition are discussed

  8. Hydrogen transport behavior of metal coatings for plasma facing components

    International Nuclear Information System (INIS)

    Anderl, R.A.; Holland, D.F.; Longhurst, G.R.

    1990-01-01

    Plasma-facing components for experimental and commercial fusion reactor studies may include cladding or coatings of refractory metals like tungsten on metallic structural substrates such as copper, vanadium alloys and austenitic stainless steel. Issues of safety and fuel economy include the potential for inventory buildup and permeation of tritium implanted into the plasma-facing surface. This paper reports on laboratory-scale studies with 3-keV D 3 + ion beams to investigate the hydrogen transport behavior in tungsten coatings on substrates of copper. These experiments entailed measurements of the deuterium re-emission and permeation rates for tungsten, copper, and tungsten-coated copper specimens at temperatures ranging from 638 K to 825 K and implanting particle fluxes of approximately 5 x 10 19 D/m 2 s. Diffusion constants and surface recombination coefficients with enhancement factors due to sputtering were obtained from these measurements. These data may be used in calculations to estimate permeation rates and inventory buildups for proposed diverter designs. 18 refs., 3 figs., 3 tabs

  9. ACCEPTABILITY ENVELOPE FOR METAL HYDRIDE-BASED HYDROGEN STORAGE SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, B.; Corgnale, C.; Tamburello, D.; Garrison, S.; Anton, D.

    2011-07-18

    The design and evaluation of media based hydrogen storage systems requires the use of detailed numerical models and experimental studies, with significant amount of time and monetary investment. Thus a scoping tool, referred to as the Acceptability Envelope, was developed to screen preliminary candidate media and storage vessel designs, identifying the range of chemical, physical and geometrical parameters for the coupled media and storage vessel system that allow it to meet performance targets. The model which underpins the analysis allows simplifying the storage system, thus resulting in one input-one output scheme, by grouping of selected quantities. Two cases have been analyzed and results are presented here. In the first application the DOE technical targets (Year 2010, Year 2015 and Ultimate) are used to determine the range of parameters required for the metal hydride media and storage vessel. In the second case the most promising metal hydrides available are compared, highlighting the potential of storage systems, utilizing them, to achieve 40% of the 2010 DOE technical target. Results show that systems based on Li-Mg media have the best potential to attain these performance targets.

  10. Topology-generating interfacial pattern formation during liquid metal dealloying.

    Science.gov (United States)

    Geslin, Pierre-Antoine; McCue, Ian; Gaskey, Bernard; Erlebacher, Jonah; Karma, Alain

    2015-11-19

    Liquid metal dealloying has emerged as a novel technique to produce topologically complex nanoporous and nanocomposite structures with ultra-high interfacial area and other unique properties relevant for diverse material applications. This process is empirically known to require the selective dissolution of one element of a multicomponent solid alloy into a liquid metal to obtain desirable structures. However, how structures form is not known. Here we demonstrate, using mesoscale phase-field modelling and experiments, that nano/microstructural pattern formation during dealloying results from the interplay of (i) interfacial spinodal decomposition, forming compositional domain structures enriched in the immiscible element, and (ii) diffusion-coupled growth of the enriched solid phase and the liquid phase into the alloy. We highlight how those two basic mechanisms interact to yield a rich variety of topologically disconnected and connected structures. Moreover, we deduce scaling laws governing microstructural length scales and dealloying kinetics.

  11. Five-fold local symmetry in metallic liquids and glasses

    International Nuclear Information System (INIS)

    Li M Z; Li F X; Zhang H P; Peng H L; Hu Y C; Wang W H

    2017-01-01

    The structure of metallic glasses has been a long-standing mystery. Owing to the disordered nature of atomic structures in metallic glasses, it is a great challenge to find a simple structural description, such as periodicity for crystals, for establishing the structure–property relationship in amorphous materials. In this paper, we briefly review the recent developments of the five-fold local symmetry in metallic liquids and glasses and the understanding of the structure–property relationship based on this parameter. Experimental evidence demonstrates that five-fold local symmetry is found to be general in metallic liquids and glasses. Comprehensive molecular dynamics simulations show that the temperature evolution of five-fold local symmetry reflects the structural evolution in glass transition in cooling process, and the structure–property relationship such as relaxation dynamics, dynamic crossover phenomena, glass transition, and mechanical deformation in metallic liquids and glasses can be well understood base on the simple and general structure parameter of five-fold local symmetry. (paper)

  12. Review of thermodinamic and mechanical properties of hydrogen-transition metal systems

    International Nuclear Information System (INIS)

    Mathias, H.; Katz, Y.

    1978-04-01

    A large body of fundamental and empirical knowledge has been acquired during many years of research concerning the interactions between hydrogen and metals, the location of hydrogen in metal structures, its mobility in metals and its influence on mechanical properties of metals. Much progress has been made in the understanding of related phenomena, and various theories have been proposed, but considerable disagreement still exist about basic mechanisms involved. The growing interest in these subjects and their important role in science and technology are well documented by many reviews and symposia. A general survey of these topics with reference to experimental results and theories related to thermodynamic and mechanical properties of hydrogen-transition metal systems, such as H-Pd, H-Ti, H-Fe etc. is given in the present review. Special emphasis is given to hydrogen embrittlement of metals

  13. The metal-carbon-fluorine system for improving hydrogen storage by using metal and fluorine with different levels of electronegativity

    Energy Technology Data Exchange (ETDEWEB)

    Im, Ji Sun; Lee, Young-Seak [Department of Fine Chemical Engineering and Applied Chemistry, BK21-E2M, Chungnam National University, Daejeon 305-764 (Korea); Park, Soo-Jin [Department of Chemistry, Inha University, Incheon 402-751 (Korea)

    2009-02-15

    In order to improve the capacity of hydrogen storage using activated carbon nanofibers, metal and fluorine were introduced into the activated carbon nanofibers by electrospinning, heat treatment, and direct fluorination. The pore structure of the samples was developed by the KOH activation process and investigated using nitrogen isotherms and micropore size distribution. The specific surface area and total pore volume approached 2800 m{sup 2}/g and 2.7 cc/g, respectively. Because of the electronegativity gap between the two elements (metal and fluorine), the electron of a hydrogen molecule can be attracted to one side. This reaction effectively guides the hydrogen molecule into the carbon nanofibers. The amount of hydrogen storage was dramatically increased in this metal-carbon-fluorine system; hydrogen content was as high as 3.2 wt%. (author)

  14. Contact angles of liquid metals on quasicrystals

    International Nuclear Information System (INIS)

    Bergman, Claire; Girardeaux, Christophe; Perrin-Pellegrino, Carine; Gas, Patrick; Dubois, Jean-Marie; Rivier, Nicolas

    2008-01-01

    Wetting with μm-sized Pb droplets on thin polycrystalline films of decagonal Al 13 Co 4 is reported. The films were prepared under high vacuum conditions in order to have Pb droplets lying on a clean surface. The method used is sequential deposition and annealing of specific stackings of Al and Co layers of nanometric thicknesses. A 300 nm thick Pb slab was then deposited on top of the films and dewetting experiments were followed in situ in a scanning Auger microprobe. The contact angle between the Pb droplet and the surface of the film is measured to be 49 deg. ± 7 deg. Further investigation performed by cross section transmission electron microscopy allows us to better characterize the interface. Taking into account the rugosity of the film, it is concluded that there is partial wetting of the film, which corresponds to a smaller contact angle. The comparison with other results obtained either with pure metals or with a cubic AlCo compound leads to the conclusion that the wetting behaviour of Pb on the surface of a decagonal compound is close to that of a metal with a high melting point and not significantly different from that of a crystalline compound with a small unit cell

  15. Liquid Acquisition Device Hydrogen Outflow Testing on the Cryogenic Propellant Storage and Transfer Engineering Design Unit

    Science.gov (United States)

    Zimmerli, Greg; Statham, Geoff; Garces, Rachel; Cartagena, Will

    2015-01-01

    As part of the NASA Cryogenic Propellant Storage and Transfer (CPST) Engineering Design Unit (EDU) testing with liquid hydrogen, screen-channel liquid acquisition devices (LADs) were tested during liquid hydrogen outflow from the EDU tank. A stainless steel screen mesh (325x2300 Dutch T will weave) was welded to a rectangular cross-section channel to form the basic LAD channel. Three LAD channels were tested, each having unique variations in the basic design. The LADs fed a common outflow sump at the aft end of the 151 cu. ft. volume aluminum tank, and included a curved section along the aft end and a straight section along the barrel section of the tank. Wet-dry sensors were mounted inside the LAD channels to detect when vapor was ingested into the LADs during outflow. The use of warm helium pressurant during liquid hydrogen outflow, supplied through a diffuser at the top of the tank, always led to early breakdown of the liquid column. When the tank was pressurized through an aft diffuser, resulting in cold helium in the ullage, LAD column hold-times as long as 60 minutes were achieved, which was the longest duration tested. The highest liquid column height at breakdown was 58 cm, which is 23 less than the isothermal bubble-point model value of 75 cm. This paper discusses details of the design, construction, operation and analysis of LAD test data from the CPST EDU liquid hydrogen test.

  16. Measurement of scattering cross sections of liquid and solid hydrogen, deuterium and deuterium hydride for thermal neutrons

    International Nuclear Information System (INIS)

    Seiffert, W.D.

    1984-01-01

    The scattering cross sections for liquid and solid normal hydrogen, para-hydrogen, deuterium and deuterium hydride were measured for thermal neutrons at various temperatures. Solid samples of para-hydrogen exhibit distinct Bragg scattering. Liquid samples of deuterium and para-hydrogen also exhibit distinct coherence phenomena, which is indicative of strong local ordering of the molecules. In para-hydrogen and deuterium hydride, the threshold for scattering with excitation of rotations is distinctly visible. The positions of the thresholds show that the molecules in liquid hydrogen are not unhindered in their movement. After the beginning of the rotational excitation the scattering cross sections of liquid and solid para-hydrogen have different shapes which is to be explained by the differences in the dynamics of the liquid and the solid specimen. 22 references

  17. Device for removing impurities from liquid metals

    International Nuclear Information System (INIS)

    Naito, Kesahiro; Yokota, Norikatsu; Shimoyashiki, Shigehiro; Takahashi, Kazuo; Ishida, Tomio.

    1984-01-01

    Purpose: To attain highly reliable and efficient impurity removal by forming temperature distribution the impurity removing device thereby providing the function of corrosion product trap, nuclear fission product trap and cold trap under the conditions suitable to the impurity removing materials. Constitution: The impurity removing device comprises a container containing impurity removing fillers. The fillers comprise material for removing corrosion products, material for removing nuclear fission products and material for removing depositions from liquid sodium. The positions for the respective materials are determined such that the materials are placed under the temperature conditions easy to attain their function depending on the temperature distribution formed in the removing device, whereby appropriate temperature condition is set to each of the materials. (Yoshino, Y.)

  18. Determination of Surface Properties of Liquid Transition Metals

    International Nuclear Information System (INIS)

    Korkmaz, S. D.

    2008-01-01

    Certain surface properties of liquid simple metals are reported. Using the expression derived by Gosh and coworkers we investigated the surface entropy of liquid transition metals namely Fe, Co and Ni. We have also computed surface tensions of the metals concerned. The pair distribution functions are calculated from the solution of Ornstein-Zernike integral equation with Rogers-Young closure using the individual version of the electron-ion potential proposed by Fioalhais and coworkers which was originally developed for solid state. The predicted values of surface tension and surface entropy are in very good agreement with available experimental data. The present study results show that the expression derived by Gosh and coworkers is very useful for the surface entropy by using Fioalhais pseudopotential and Rogers-Young closure

  19. Ionizable polyethers as specific metal ion carriers in liquid-liquid extraction and liquid membrane separations

    International Nuclear Information System (INIS)

    Walkowiak, W.; Charewicz, W.A.; Bartsch, R.A.; Ndip, G.M.

    1988-01-01

    Consideration is given to results of investigations into competitive extraction and penetration through a liquid membrane of alkali and alkaline earth cations from aqueous solutions by a series of lipophilic and ionizable acyclic polyethers of various molecular structure. It is shown that specificity and selectiviy of cation carriers in liquid-liquid extraction and liquid membrane separation depend on molecular structure of acyclic polyethers

  20. Hydrogen and helium in metals: positron lifetime experiments. Quarterly report 3. quarter 1987

    International Nuclear Information System (INIS)

    Rajainmaeki, Hannu.

    1987-09-01

    This thesis reviews a new approach to studying the role of hydrogen and helium in defect recovery of metals by the positron lifetime technique. A cryostat has been built at the University of Jyvaeskylae for irradiating and/or implaning solids by high-energy proton or helium beams from the MC-20 cyclotron. The samples can be kept continuously below 20 K and the isochronal annealings and the subsequent positron lifetime measurements are carried ou in the same cryostat after the irradiations. During the implantations below 20 K both impuities (H or He) and Frenkel pairs are produced simultaneously. By measuring positron lifetimes during the annealing detailed information is obtained about radiation damage, impurity-defect interactions, lattice defect annealing, void nucleation and formation of helium bubbles. In this work positron lifetime spectroscopy has been utilized for the first time to study defect recovery below the liquid nitrogen temperature (77 K). The annealing stages are investigated in aluminium, nickel and molybdenum in the temperature range 20-700 K. Hydrogen is found to get trapped at vacancies in all the studied metals with binding energies 0.53+-0.04 and 1.6+-0.1 eV, respectively. Trapped hydrogen retards the vacancy migration in Al and Mo, while H-vancancy pairs dissociate in Ni below the free vacancy migration stage. helium gets deeply trapped at vacancies in Al and migrates substitutionally with the activation energy of 1.3+-0.1 eV. Helium-vacancy pairs are observed to nucleate into clusters and form helium bubbles which are stable up to the Al melting temperature. The growth mechanisms for the bubbles are established as thermal vacancy absorption and bubble migration/coalescence