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Sample records for liquid metal eurisol

  1. Liquid metal cold trap

    DOEpatents

    Hundal, Rolv

    1976-01-01

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

  2. Liquid metal drop ejection

    NASA Technical Reports Server (NTRS)

    Khuri-Yakub, B. T.

    1993-01-01

    The aim of this project was to demonstrate the possibility of ejecting liquid metals using drop on demand printing technology. The plan was to make transducers for operation in the 100 MHz frequency range and to use these transducers to demonstrate the ability to eject drops of liquid metals such as gallium. Two transducers were made by indium bonding piezoelectric lithium niobate to quartz buffer rods. The lithium niobate plates were thinned by mechanical polishing to a thickness of 37 microns for operation at 100 MHz. Hemispherical lenses were polished in the opposite ends of the buffer rods. The lenses, which focus the sound waves in the liquid metal, had an F-number equals 1. A mechanical housing was made to hold the transducers and to allow precise control over the liquid level above the lens. We started by demonstrating the ability to eject drops of water on demand. The drops of water had a diameter of 15 microns which corresponds to the wavelength of the sound wave in the water. A videotape of this ejection was made. We then used a mixture of Gallium and Indium (used to lower the melting temperature of the Gallium) to demonstrate the ejection of liquid metal drops. This proved to be difficult because of the oxide skin which forms on the surface of the liquid. In some instances, we were able to eject metal drops, however, this was not consistent and reproducible. An experiment was set up at NASA-Lewis to stabilize the process of drop on demand liquid metal ejection. The object was to place the transducer and liquid metal in a vacuum station so that no oxide would form on the surface. We were successful in demonstrating that liquid metals could be ejected on demand and that this technology could be used for making sheet metal in space.

  3. Liquid metal electric pump

    DOEpatents

    Abbin, Joseph P.; Andraka, Charles E.; Lukens, Laurance L.; Moreno, James B.

    1992-01-01

    An electrical pump for pumping liquid metals to high pressures in high temperature environments without the use of magnets or moving mechanical parts. The pump employs a non-porous solid electrolyte membrane, typically ceramic, specific to the liquid metal to be pumped. A DC voltage is applied across the thickness of the membrane causing ions to form and enter the membrane on the electrically positive surface, with the ions being neutralized on the opposite surface. This action provides pumping of the liquid metal from one side of the non-porous solid electrolyte membrane to the other.

  4. Liquid metal hydrogen barriers

    DOEpatents

    Grover, George M.; Frank, Thurman G.; Keddy, Edward S.

    1976-01-01

    Hydrogen barriers which comprise liquid metals in which the solubility of hydrogen is low and which have good thermal conductivities at operating temperatures of interest. Such barriers are useful in nuclear fuel elements containing a metal hydride moderator which has a substantial hydrogen dissociation pressure at reactor operating temperatures.

  5. Liquid-metal corrosion

    SciTech Connect

    Chopra, O.K.; DeVan, J.H.; Smith, D.L.; Sze, D.K.; Tortorelli, P.F.

    1985-09-01

    A review of corrosion and environmental effects on the mechanical properties of candidate structural alloys for use with liquid metals in fusion reactors is presented. The corrosion/mass transfer behavior of austenitic and ferritic steels and vanadium-base alloys is evaluated to determine the preliminary operating temperature limits for circulating and static liquid-lithium and Pb-17Li systems. The influence of liquid-metal environment on the mechanical properties of structural materials is discussed. Corrosion effects of nitrate and fluoride salts are presented. Requirements for additional data are identified.

  6. Liquid metal pump

    DOEpatents

    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.

  7. Liquid metal thermal electric converter

    DOEpatents

    Abbin, Joseph P.; Andraka, Charles E.; Lukens, Laurance L.; Moreno, James B.

    1989-01-01

    A liquid metal thermal electric converter which converts heat energy to electrical energy. The design of the liquid metal thermal electric converter incorporates a unique configuration which directs the metal fluid pressure to the outside of the tube which results in the structural loads in the tube to be compressive. A liquid metal thermal electric converter refluxing boiler with series connection of tubes and a multiple cell liquid metal thermal electric converter are also provided.

  8. Handbook of liquid metals

    NASA Technical Reports Server (NTRS)

    Ukanwa, A. O.

    1976-01-01

    Metals are described by physical appearance followed by atomic weight, atomic number, and valence. Data includes laboratory handling and safety procedures, heat transfer correlations, diffusion coefficients in liquid gallium/indium solution, melting and boiling points, thermal conductivity, heat capacity, and electrical resistivity.

  9. Liquid metal thermoacoustic engine

    SciTech Connect

    Swift, G.W.; Migliori, A.; Wheatley, J.C.

    1986-01-01

    We are studying a liquid metal thermoacoustic engine both theoretically and experimentally. This type of engine promises to produce large quantities of electrical energy from heat at modest efficiency with no moving parts. A sound wave is usually thought of as consisting of pressure oscillations, but always attendant to the pressure oscillation are temperature oscillations. The combination produces a rich variety of ''thermoacoustic'' effects. These effects are usually so small that they are never noticed in everyday life; nevertheless under the right circumstances they can be harnessed to produce powerful heat engines, heat pumps, and refrigerators. In our liquid metal thermoacoustic engine, heat flow from a high temperature source to a low temperature sink generates a high-amplitude standing acoustic wave in liquid sodium. This acoustic power is converted to electric power by a simple magnetohydrodynamic effect at the acoustic oscillation frequency. We have developed a detailed thermoacoustic theory applicable to this engine, and find that a reasonably designed liquid sodium engine operating between 700/sup 0/C and 100/sup 0/C should generate about 60 W/cm/sup 2/ of acoustic power at about 1/3 of Carnot's efficiency. Construction of a 3000 W-thermal laboratory model engine has just been completed, and we have exciting preliminary experimental results as of the time of preparation of this manuscript showing, basically, that the engine works. We have also designed and built a 1 kHz liquid sodium magnetohydrodynamic generator and have extensive measurements on it. It is now very well characterized both experimentally and theoretically. The first generator of its kind, it already converts acoustic power to electric power with 40% efficiency. 16 refs., 5 figs.

  10. Method of foaming a liquid metal

    DOEpatents

    Fischer, Albert K.; Johnson, Carl E.

    1980-01-01

    The addition of a small quantity of barium to liquid metal NaK or sodium has been found to promote foam formation and improve bubble retention in the liquid metal. A stable liquid metal foam will provide a more homogeneous liquid metal flow through the channel of a two-phase liquid metal MHD power generator to improve operating efficiency.

  11. EXPERIMENTAL LIQUID METAL FUEL REACTOR

    DOEpatents

    Happell, J.J.; Thomas, G.R.; Denise, R.P.; Bunts, J.L. Jr.

    1962-01-23

    A liquid metal fuel nuclear fission reactor is designed in which the fissionable material is dissolved or suspended in a liquid metal moderator and coolant. The liquid suspension flows into a chamber in which a critical amount of fissionable material is obtained. The fluid leaves the chamber and the heat of fission is extracted for power or other utilization. The improvement is in the support arrangement for a segrnented graphite core to permit dif ferential thermal expansion, effective sealing between main and blanket liquid metal flows, and avoidance of excessive stress development in the graphite segments. (AEC)

  12. Solute diffusion in liquid metals

    NASA Technical Reports Server (NTRS)

    Bhat, B. N.

    1973-01-01

    A gas model of diffusion in liquid metals is presented. In this model, ions of liquid metals are assumed to behave like the molecules in a dense gas. Diffusion coefficient of solute is discussed with reference to its mass, ionic size, and pair potential. The model is applied to the case of solute diffusion in liquid silver. An attempt was made to predict diffusion coefficients of solutes with reasonable accuracy.

  13. LIQUID METAL COMPOSITIONS CONTAINING URANIUM

    DOEpatents

    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.

  14. Actively convected liquid metal divertor

    NASA Astrophysics Data System (ADS)

    Shimada, Michiya; Hirooka, Yoshi

    2014-12-01

    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.

  15. Computer simulation of liquid metals

    NASA Astrophysics Data System (ADS)

    Belashchenko, D. K.

    2013-12-01

    Methods for and the results of the computer simulation of liquid metals are reviewed. Two basic methods, classical molecular dynamics with known interparticle potentials and the ab initio method, are considered. Most attention is given to the simulated results obtained using the embedded atom model (EAM). The thermodynamic, structural, and diffusion properties of liquid metal models under normal and extreme (shock) pressure conditions are considered. Liquid-metal simulated results for the Groups I - IV elements, a number of transition metals, and some binary systems (Fe - C, Fe - S) are examined. Possibilities for the simulation to account for the thermal contribution of delocalized electrons to energy and pressure are considered. Solidification features of supercooled metals are also discussed.

  16. Liquid metal boiling inception

    NASA Technical Reports Server (NTRS)

    Sabin, C. M.; Poppendiek, H. F.; Mouritzen, G.; Meckel, P. T.; Cloakey, J. E.

    1972-01-01

    An experimental study of the inception of boiling in potassium in forced convection is reported. The boiler consisted of a 0.19-inch inside diameter, niobium-1% zirconium boiler tube approximately six feet long. Heating was accomplished by direct electrical tube wall conduction. Experiments were performed with both all-liquid fill and two-phase fill startup sequences and with a range of flow rates, saturation temperatures, inert gas levels, and fill liquid temperatures. Superheat of the liquid above the equilibrium saturation temperature was observed in all the experiments. Incipient boiling liquid superheat ranged from a few degrees to several hundred. Comparisons of these data with other data and with several analytical treatments are presented.

  17. Metal pad instabilities in liquid metal batteries.

    PubMed

    Zikanov, Oleg

    2015-12-01

    A mechanical analogy is used to analyze the interaction between the magnetic field, electric current, and deformation of interfaces in liquid metal batteries. In the framework of a low-mode, nondissipative, linear stability model, it is found that, during charging or discharging, a sufficiently large battery is prone to instabilities of two types. One is similar to the metal pad instability known to exist in the aluminum reduction cells. Another type is new. It is related to the destabilizing effect of the Lorentz force formed by the azimuthal magnetic field induced by the base current, and the current perturbations caused by the local variations of the thickness of the electrolyte layer.

  18. Metal pad instabilities in liquid metal batteries

    NASA Astrophysics Data System (ADS)

    Zikanov, Oleg

    2015-12-01

    A mechanical analogy is used to analyze the interaction between the magnetic field, electric current, and deformation of interfaces in liquid metal batteries. In the framework of a low-mode, nondissipative, linear stability model, it is found that, during charging or discharging, a sufficiently large battery is prone to instabilities of two types. One is similar to the metal pad instability known to exist in the aluminum reduction cells. Another type is new. It is related to the destabilizing effect of the Lorentz force formed by the azimuthal magnetic field induced by the base current, and the current perturbations caused by the local variations of the thickness of the electrolyte layer.

  19. Metals Separation by Liquid Extraction.

    ERIC Educational Resources Information Center

    Malmary, G.; And Others

    1984-01-01

    As part of a project focusing on techniques in industrial chemistry, students carry out experiments on separating copper from cobalt in chloride-containing aqueous solution by liquid extraction with triisoctylamine solvent and search the literature on the separation process of these metals. These experiments and the literature research are…

  20. Liquid Metal Drop Impingement

    NASA Astrophysics Data System (ADS)

    Che, Judy; Han, Jaehoon; Tryggvason, Gretar; Ceccio, Steven

    1996-11-01

    "Ballistic Partical Manufacturing" is a process in which individual drops are layered to form a part. We examine how metal drops deform and solidify, and how the solidification rate affects the material microstructure using both numerical simulations and experiments. A single set of equations governing the conservation of mass, energy, and momentum are written for all phases involved, and the phase boundary is treated as an imbedded interface by adding the appropriate source terms. We have simulated single drops colliding with a surface using a simple model which assumes that a melt solidifies below the melting point. Although simple, this model captures many aspects of the fluid flow and solidification. The experimental apparatus creates a single drop of prescribed size and propels it toward a cooled substrate. Favorable comparisons of experimental and numerical results have been achieved.

  1. Transformable liquid-metal nanomedicine

    PubMed Central

    Lu, Yue; Hu, Quanyin; Lin, Yiliang; Pacardo, Dennis B.; Wang, Chao; Sun, Wujin; Ligler, Frances S.; Dickey, Michael D.; Gu, Zhen

    2015-01-01

    To date, numerous inorganic nanocarriers have been explored for drug delivery systems (DDSs). However, the clinical application of inorganic formulations has often been hindered by their toxicity and failure to biodegrade. We describe here a transformable liquid-metal nanomedicine, based on a core–shell nanosphere composed of a liquid-phase eutectic gallium-indium core and a thiolated polymeric shell. This formulation can be simply produced through a sonication-mediated method with bioconjugation flexibility. The resulting nanoparticles loaded with doxorubicin (Dox) have an average diameter of 107 nm and demonstrate the capability to fuse and subsequently degrade under a mildly acidic condition, which facilitates release of Dox in acidic endosomes after cellular internalization. Equipped with hyaluronic acid, a tumour-targeting ligand, this formulation displays enhanced chemotherapeutic inhibition towards the xenograft tumour-bearing mice. This liquid metal-based DDS with fusible and degradable behaviour under physiological conditions provides a new strategy for engineering theranostic agents with low toxicity. PMID:26625944

  2. Transformable liquid-metal nanomedicine

    NASA Astrophysics Data System (ADS)

    Lu, Yue; Hu, Quanyin; Lin, Yiliang; Pacardo, Dennis B.; Wang, Chao; Sun, Wujin; Ligler, Frances S.; Dickey, Michael D.; Gu, Zhen

    2015-12-01

    To date, numerous inorganic nanocarriers have been explored for drug delivery systems (DDSs). However, the clinical application of inorganic formulations has often been hindered by their toxicity and failure to biodegrade. We describe here a transformable liquid-metal nanomedicine, based on a core-shell nanosphere composed of a liquid-phase eutectic gallium-indium core and a thiolated polymeric shell. This formulation can be simply produced through a sonication-mediated method with bioconjugation flexibility. The resulting nanoparticles loaded with doxorubicin (Dox) have an average diameter of 107 nm and demonstrate the capability to fuse and subsequently degrade under a mildly acidic condition, which facilitates release of Dox in acidic endosomes after cellular internalization. Equipped with hyaluronic acid, a tumour-targeting ligand, this formulation displays enhanced chemotherapeutic inhibition towards the xenograft tumour-bearing mice. This liquid metal-based DDS with fusible and degradable behaviour under physiological conditions provides a new strategy for engineering theranostic agents with low toxicity.

  3. Liquid metal Flow Meter - Final Report

    SciTech Connect

    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.

  4. Surface chemistry of liquid metals

    NASA Technical Reports Server (NTRS)

    Mann, J. Adin, Jr.; Peebles, Henry; Peebles, Diamond; Rye, Robert; Yost, Fred

    1993-01-01

    The fundamental surface chemistry of the behavior of liquid metals spreading on a solid substrate is not at all well understood. Each of these questions involves knowing the details of the structure of interfaces and their dynamics. For example the structure of a monolayer of tin oxide on pure liquid tin is unknown. This is in contrast to the relatively large amount of data available on the structure of copper oxide monolayers on solid, pure copper. However, since liquid tin has a vapor pressure below 10(exp -10)torr for a reasonable temperature range above its melting point, it is possible to use the techniques of surface science to study the geometric, electronic and vibrational structures of these monolayers. In addition, certain techniques developed by surface chemists for the study of liquid systems can be applied to the ultra-high vacuum environment. In particular we have shown that light scattering spectroscopy can be used to study the surface tension tensor of these interfaces. The tin oxide layer in particular is very interesting in that the monolayer is rigid but admits of bending. Ellipsometric microscopy allows the visualization of monolayer thick films and show whether island formation occurs at various levels of dosing.

  5. Liquid metal embrittlement. [crack propagation in metals with liquid metal in crack space

    NASA Technical Reports Server (NTRS)

    Tiller, W. A.

    1973-01-01

    Crack propagation is discussed for metals with liquid metal in the crack space. The change in electrochemical potential of an electron in a metal due to changes in stress level along the crack surface was investigated along with the change in local chemistry, and interfacial energy due to atomic redistribution in the liquid. Coupled elastic-elastrostatic equations, stress effects on electron energy states, and crack propagation via surface roughening are discussed.

  6. Thermodynamic properties of liquid metals /A review/.

    NASA Technical Reports Server (NTRS)

    Margrave, J. L.

    1970-01-01

    Summary of the current state of knowledge about the thermodynamic properties of liquid metals, including heats of fusion and heat capacities. A table is presented of consistent thermodynamic data for liquid metals, including estimates for the many high-melting transition metals which have not yet been studied, based on new levitation data and on periodic table correlations.

  7. Bearing for liquid metal pump

    DOEpatents

    Dickinson, Robert J.; Wasko, John; Pennell, William E.

    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.

  8. Liquid metal cooled nuclear reactor plant system

    DOEpatents

    Hunsbedt, Anstein; Boardman, Charles E.

    1993-01-01

    A liquid metal cooled nuclear reactor having a passive cooling system for removing residual heat resulting for fuel decay during reactor shutdown, or heat produced during a mishap. The reactor system is enhanced with sealing means for excluding external air from contact with the liquid metal coolant leaking from the reactor vessel during an accident. The invention also includes a silo structure which resists attack by leaking liquid metal coolant, and an added unique cooling means.

  9. Technique for detecting liquid metal leaks

    DOEpatents

    Bauerle, James 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.

  10. Radiopure metal-loaded liquid scintillator

    SciTech Connect

    Rosero, Richard; Yeh, Minfang

    2015-08-17

    Metal-loaded liquid scintillator plays a key role in particle and nuclear physics experiments. The applications of metal ions in various neutrino experiments and the purification methods for different scintillator components are discussed in this paper.

  11. Radiopure Metal-Loaded Liquid Scintillator

    SciTech Connect

    Rosero, Richard; Yeh, Minfang

    2015-03-18

    Metal-loaded liquid scintillator plays a key role in particle and nuclear physics experiments. The applications of metal ions in various neutrino experiments and the purification methods for different scintillator components are discussed in this paper.

  12. Schottky Barrier with Liquid Metal

    NASA Astrophysics Data System (ADS)

    Modi, B. P.; Patel, K. D.

    2011-12-01

    Schottky barrier with liquid metal may provide an attractive and new opportunity to look into various aspect of the evolution of Schottky interfaces in a relatively beneficial manner [1]. Here gallium-silicon diode has been fabricated and investigated especially around the melting point of gallium. Analysis of data no barrier height exhibits an anomalous change in the sense that there is a sharp deterioration in the rectifying nature near this temperature. It is believed to be related changes the phase transition driven physical process e.g. breaking of bonds both between gallium atoms and between gallium atoms and silicon interface; change from long range to short range order in gallium. Strain relaxations at the interface etc.

  13. Heat-Powered Pump for Liquid Metals

    NASA Technical Reports Server (NTRS)

    Campana, R. J.

    1986-01-01

    Proposed thermoelectromagnetic pump for liquid metal powered by waste heat; needs no battery, generator, or other external energy source. Pump turns part of heat in liquid metal into pumping energy. In combination with primary pump or on its own, thermoelectric pump circulates coolant between reactor and radiator. As long as there is decay heat to be removed, unit performs function.

  14. Liquid metal ion source and alloy

    DOEpatents

    Clark, Jr., William M.; Utlaut, Mark W.; Behrens, Robert G.; Szklarz, Eugene G.; Storms, Edmund K.; Santandrea, Robert P.; Swanson, Lynwood W.

    1988-10-04

    A liquid metal ion source and alloy, wherein the species to be emitted from the ion source is contained in a congruently vaporizing alloy. In one embodiment, the liquid metal ion source acts as a source of arsenic, and in a source alloy the arsenic is combined with palladium, preferably in a liquid alloy having a range of compositions from about 24 to about 33 atomic percent arsenic. Such an alloy may be readily prepared by a combustion synthesis technique. Liquid metal ion sources thus prepared produce arsenic ions for implantation, have long lifetimes, and are highly stable in operation.

  15. Sewage sludge dewatering using flowing liquid metals

    DOEpatents

    Carlson, Larry W.

    1986-01-01

    A method and apparatus for reducing the moisture content of a moist sewage sludge having a moisture content of about 50% to 80% and formed of small cellular micro-organism bodies having internally confined water is provided. A hot liquid metal is circulated in a circulation loop and the moist sewage sludge is injected in the circulation loop under conditions of temperature and pressure such that the confined water vaporizes and ruptures the cellular bodies. The vapor produced, the dried sludge, and the liquid metal are then separated. Preferably, the moist sewage sludge is injected into the hot liquid metal adjacent the upstream side of a venturi which serves to thoroughly mix the hot liquid metal and the moist sewage sludge. The venturi and the drying zone after the venturi are preferably vertically oriented. The dried sewage sludge recovered is available as a fuel and is preferably used for heating the hot liquid metal.

  16. Compressibility of liquid-metallic hydrogen

    NASA Astrophysics Data System (ADS)

    MacDonald, A. H.

    1983-05-01

    An expression for the compressibility κ of liquid-metallic hydrogen, derived within adiabatic and linear screening approximations, is presented. Terms in the expression for κ have been associated with Landau parameters of the two-component Fermi liquid. The compressibility found for the liquid state is much larger than the compressibility which would be expected in the solid state.

  17. Tokamak with liquid metal toroidal field coil

    DOEpatents

    Ohkawa, Tihiro; Schaffer, Michael 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.

  18. Liquid metal cooling of synchrotron optics

    SciTech Connect

    Smither, R.K.

    1992-09-01

    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.

  19. Development of a liquid metal slip ring

    NASA Technical Reports Server (NTRS)

    Weinberger, S. M.

    1972-01-01

    A liquid metal slip ring/solar orientation mechanism was designed and a model tested. This was a follow-up of previous efforts for the development of a gallium liquid metal slip ring in which the major problem was the formation and ejection of debris. A number of slip ring design approaches were studied. The probe design concept was fully implemented with detail drawings and a model was successfully tested for dielectric strength, shock vibration, acceleration and operation. The conclusions are that a gallium liquid metal slip ring/solar orientation mechanism is feasible and that the problem of debris formation and ejection has been successfully solved.

  20. Electromagnetic flow rate meter. [for liquid metals

    NASA Technical Reports Server (NTRS)

    Banks, B. A. (Inventor)

    1974-01-01

    A liquid metal, whose flow rate is to be determined, is directed through a chamber made of electrically-insulating material on which there is impressed a magnetic field perpendicular to the direction of flow of the liquid metal. The magnetic field is made to increase in strength in a downstream direction of the flow of liquid metal. At least a pair of electrodes are disposed in the chamber traversely and perpendicular to the direction of flow and an ammeter is connected between the electrodes. Electrodes may be disposed in the top or the bottom of the chamber and each may be segmented. Oppositely disposed electrodes may be used with at least one dividing wall extending from each electrode to cause reversal of the direction of flow of the liquid metal. The magnetic field may be provided by electromagnets or permanent magnets such as shaded pole permanent magnets.

  1. Liquid metal cooled divertor for ARIES

    SciTech Connect

    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{sup 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.

  2. Liquid-Metal-Fed Pulsed Plasma Thrusters

    NASA Technical Reports Server (NTRS)

    Markusic, Thomas

    2003-01-01

    Liquid metal propellants may provide a path toward more reliable and efficient pulsed plasma thrusters (PPTs). Conceptual thruster designs which eliminate the need for high current switches and propellant metering valves are described. Propellant loading techniques are suggested that, at least in principle, show promise to increase propellant utilization, dynamic, and electrical efficiency. Experimental results from a prototype electromagnetically-pumped propellant feed system, and experiments in the initiation of arc discharges in liquid metal droplets, are presented.

  3. Solar driven liquid metal MHD power generator

    NASA Technical Reports Server (NTRS)

    Lee, J. H.; Hohl, F. (Inventor)

    1983-01-01

    A solar energy collector focuses solar energy onto a solar oven which is attached to a mixer which in turn is attached to the channel of a MHD generator. Gas enters the oven and a liquid metal enters the mixer. The gas/liquid metal mixture is heated by the collected solar energy and moves through the MHD generator thereby generating electrical power. The mixture is then separated and recycled.

  4. Solar driven liquid metal MHD power generator

    NASA Astrophysics Data System (ADS)

    Lee, J. H.; Hohl, F.

    1983-06-01

    A solar energy collector focuses solar energy onto a solar oven which is attached to a mixer which in turn is attached to the channel of a MHD generator. Gas enters the oven and a liquid metal enters the mixer. The gas/liquid metal mixture is heated by the collected solar energy and moves through the MHD generator thereby generating electrical power. The mixture is then separated and recycled.

  5. Reduction of Metal Oxide to Metal using Ionic Liquids

    SciTech Connect

    Dr. Ramana Reddy

    2012-04-12

    A novel pathway for the high efficiency production of metal from metal oxide means of electrolysis in ionic liquids at low temperature was investigated. The main emphasis was to eliminate the use of carbon and high temperature application in the reduction of metal oxides to metals. The emphasis of this research was to produce metals such as Zn, and Pb that are normally produced by the application of very high temperatures. The reduction of zinc oxide to zinc and lead oxide to lead were investigated. This study involved three steps in accomplishing the final goal of reduction of metal oxide to metal using ionic liquids: 1) Dissolution of metal oxide in an ionic liquid, 2) Determination of reduction potential using cyclic voltammetry (CV) and 3) Reduction of the dissolved metal oxide. Ionic liquids provide additional advantage by offering a wide potential range for the deposition. In each and every step of the process, more than one process variable has been examined. Experimental results for electrochemical extraction of Zn from ZnO and Pb from PbO using eutectic mixtures of Urea ((NH2)2CO) and Choline chloride (HOC2H4N(CH3)3+Cl-) or (ChCl) in a molar ratio 2:1, varying voltage and temperatures were carried out. Fourier Transform Infra-Red (FTIR) spectroscopy studies of ionic liquids with and without metal oxide additions were conducted. FTIR and induction coupled plasma spectroscopy (ICPS) was used in the characterization of the metal oxide dissolved ionic liquid. Electrochemical experiments were conducted using EG&G potentiostat/galvanostat with three electrode cell systems. Cyclic voltammetry was used in the determination of reduction potentials for the deposition of metals. Chronoamperometric experiments were carried out in the potential range of -0.6V to -1.9V for lead and -1.4V to -1.9V for zinc. The deposits were characterized using XRD and SEM-EDS for phase, morphological and elemental analysis. The results showed that pure metal was deposited on the cathode

  6. Recent developments in liquid-metal embrittlement

    NASA Technical Reports Server (NTRS)

    Stoloff, N. S.

    1979-01-01

    The paper reviews developments in liquid-metal embrittlement of the past 7 years including data on cyclic loading. Embrittlement by solid and liquid metals and by hydrogen has many common features, although the mechanism of embrittler transport differs. Fracture may occur in each type of embrittlement by environmentally assisted shear and by reduced cohesion; embrittlement under cyclic loading has been widely observed, with stress level, temperature, and substrate alloy composition and grain size being the major variables. The degree of embrittlement between any combination of environment (i.e. hydrogen, liquid metal, or solid metal) and substrate depends upon the strength of the interaction with the substrate, the kinetics of embrittler transport, the mutual solubility of embrittler and substrate, and a large number of test and microstructural conditions. A method of calculating the most significant of these variables and the strength of interaction was reviewed and predictions of embrittlement in previously untested couples were made.

  7. Liquid metal porous matrix sliding electrical contact: A concept

    NASA Technical Reports Server (NTRS)

    Ferguson, H.

    1973-01-01

    Concept utilizes porous metal or nonmetal matrix containing liquid metal in porous structure and confines liquid metal to contact area between rotor and brush by capillary forces. System may also be used to lubricate bearing systems.

  8. Double-duct liquid metal magnetohydrodynamic engine

    DOEpatents

    Haaland, Carsten M.

    1995-01-01

    An internal combustion, liquid metal (LM) magnetohydrodynamic (MHD) engine and an alternating current (AC) magnetohydrodynamic generator, are used in combination to provide useful AC electric energy output. The engine design has-four pistons and a double duct configuration, with each duct containing sodium potassium liquid metal confined between free pistons located at either end of the duct. The liquid metal is forced to flow back and forth in the duct by the movement of the pistons, which are alternatively driven by an internal combustion process. In the MHD generator, the two LM-MHD ducts pass in close proximity through a Hartmann duct with output transformer. AC power is produced by operating the engine with the liquid metal in the two generator ducts always flowing in counter directions. The amount of liquid metal maintained in the ducts may be varied. This provides a variable stroke length for the pistons. The engine/generator provides variable AC power at variable frequencies that correspond to the power demands of the vehicular propulsion. Also the engine should maintain nearly constant efficiency throughout the range of power usage. Automobiles and trucks could be powered by the invention, with no transmission or power converter devices being required.

  9. Double-duct liquid metal magnetohydrodynamic engine

    DOEpatents

    Haaland, Carsten M.

    1997-01-01

    An internal combustion, liquid metal (LM) magnetohydrodynamic (MHD) engine and an alternating current (AC) magnetohydrodynamic generator, are used in combination to provide useful AC electric energy output. The engine design has four pistons and a double duct configuration, with each duct containing sodium potassium liquid metal confined between free pistons located at either end of the duct. The liquid metal is forced to flow back and forth in the duct by the movement of the pistons, which are alternatively driven by an internal combustion process. In the MHD generator, the two LM-MHD ducts pass in close proximity through a Hartmann duct with output transformer. AC power is produced by operating the engine with the liquid metal in the two generator ducts always flowing in counter directions. The amount of liquid metal maintained in the ducts may be varied. This provides a variable stroke length for the pistons. The engine/generator provides variable AC power at variable frequencies that correspond to the power demands of the vehicular propulsion. Also the engine should maintain nearly constant efficiency throughout the range of power usage. Automobiles and trucks could be powered by the invention, with no transmission or power converter devices being required.

  10. Mixing in a liquid metal electrode

    SciTech Connect

    Kelley, DH; Sadoway, DR

    2014-05-01

    Fluid mixing has first-order importance for many engineering problems in mass transport, including design and optimization of liquid-phase energy storage devices. Liquid metal batteries are currently being commercialized as a promising and economically viable technology for large-scale energy storage on worldwide electrical grids. But because these batteries are entirely liquid, fluid flow and instabilities may affect battery robustness and performance. Here we present estimates of flow magnitude and ultrasound measurements of the flow in a realistic liquid metal electrode. We find that flow does substantially affect mass transport by altering the electrode mixing time. Above a critical electrical current density, the convective flow organizes and gains speed, which promotes transport and would yield improved battery efficiency. (C) 2014 AIP Publishing LLC.

  11. Liquid metal suspensions for turbulent dynamo experiments

    NASA Astrophysics Data System (ADS)

    Brown, E.; Xu, Q.; Oudalov, N.; Guo, Q.; Jaeger, H.

    2012-12-01

    I will discuss the potential for using suspensions of magnetic particles in liquid metals for magnetohydrodynamics experiments in the laboratory. The ability to tune material properties of such suspensions could allow for experiments that in a parameter regime comparable to Earth's outer core. Specifically, high conductivity of the liquid metal and high magnetic permeability of the particles could reach the large magnetic Reynolds numbers required to generate a dynamo effect in the laboratory, while additional suspended particles can independently control viscosity and thus the Reynolds number. A key experimental challenge is to achieve good wetting of micron-sized suspended particles by liquid metals to produce homogenous suspensions. I will present data on the wetting and rheological properties of liquid gallium and a eutectic gallium-indium alloy (eGaIn). A rheometer is used to measure a yield stress due to an oxide skin on the surface of liquid metals, which can be controlled and eliminated by surrounding the metal with an acid bath. We find that this yield stress and the contact contact angle on solid surfaces change at the same critical acid concentration, thereby quantitatively confirming that the wettability of these liquid metals is due to the oxide skin, which can be controlled with the acid bath. This reveals a tunable tradeoff between good wetting for better suspension and a yield stress which introduces non-Newtonian fluid behavior. We find that even with this yield stress from an oxide skin or with a small fraction of particles suspended, the shear stresses at high Reynolds numbers match those of Newtonian fluids, suggesting that non-Newtonian fluid properties will not interfere with the turbulent flow structures that may be relevant to dynamos.

  12. Magnetohydrodynamic effects in liquid metal batteries

    NASA Astrophysics Data System (ADS)

    Stefani, F.; Galindo, V.; Kasprzyk, C.; Landgraf, S.; Seilmayer, M.; Starace, M.; Weber, N.; Weier, T.

    2016-07-01

    Liquid metal batteries (LMBs) consist of two liquid metal electrodes and a molten salt ionic conductor sandwiched between them. The density ratios allow for a stable stratification of the three layers. LMBs were already considered as part of energy conversion systems in the 1960s and have recently received renewed interest for economical large-scale energy storage. In this paper, we concentrate on the magnetohydrodynamic aspects of this cell type with special focus on electro-vortex flows and possible effects of the Tayler instability.

  13. Liquid-Metal-Fed Pulsed Plasma Thrusters

    NASA Technical Reports Server (NTRS)

    Markusic, Thomas

    2004-01-01

    A short document proposes liquid-metal-fed pulsed plasma thrusters for small spacecraft. The propellant liquid for such a thruster would be a low-melting-temperature metal that would be stored molten in an unpressurized, heated reservoir and would be pumped to the thruster by a magnetohydrodynamic coupler. The liquid would enter the thruster via a metal tube inside an electrically insulating ceramic tube. A capacitor would be connected between the outlet of the metal tube and the outer electrode of the thruster. The pumping would cause a drop of liquid to form at the outlet, eventually growing large enough to make contact with the outer electrode. Contact would close the circuit through the capacitor, causing the capacitor to discharge through the drop. The capacitor would have been charged with enough energy that the discharge would vaporize, ionize, and electromagnetically accelerate the contents of the metal drop. The resulting plasma would be ejected at a speed of about 50 km/s. The vaporization of the drop would reopen the circuit through the capacitor, enabling recharging of the capacitor. As pumping continued, a new drop would grow and the process would repeat.

  14. Holographic Metals and the Fractionalized Fermi Liquid

    SciTech Connect

    Sachdev, Subir

    2010-10-08

    We show that there is a close correspondence between the physical properties of holographic metals near charged black holes in anti-de Sitter (AdS) space, and the fractionalized Fermi liquid phase of the lattice Anderson model. The latter phase has a ''small'' Fermi surface of conduction electrons, along with a spin liquid of local moments. This correspondence implies that certain mean-field gapless spin liquids are states of matter at nonzero density realizing the near-horizon, AdS{sub 2}xR{sup 2} physics of Reissner-Nordstroem black holes.

  15. Holographic metals and the fractionalized fermi liquid.

    PubMed

    Sachdev, Subir

    2010-10-01

    We show that there is a close correspondence between the physical properties of holographic metals near charged black holes in anti-de Sitter (AdS) space, and the fractionalized Fermi liquid phase of the lattice Anderson model. The latter phase has a "small" Fermi surface of conduction electrons, along with a spin liquid of local moments. This correspondence implies that certain mean-field gapless spin liquids are states of matter at nonzero density realizing the near-horizon, AdS₂ × R² physics of Reissner-Nordström black holes. PMID:21230891

  16. Paths of progress in liquid metal processing

    NASA Astrophysics Data System (ADS)

    McLean, A.; Soda, H.; Sommerville, I. D.

    1995-04-01

    Industry has identified three major issues as being fundamental to future technological developments: process step elimination, product-process integration, and intelligent processing. This article reviews these concepts by discussing recent research at the University of Toronto on plasma processing, netshape casting, and diagnostic sensors for the evaluation of liquid metal quality.

  17. Conduction in fully ionized liquid metals

    NASA Technical Reports Server (NTRS)

    Stevenson, D. J.; Ashcroft, N. W.

    1973-01-01

    Electron transport is considered in high density fully ionized liquid metals. Ionic structure is described in terms of hard-sphere correlation functions and the scattering is determined from self-consistently screened point ions. Applications to the physical properties of the deep interior of Jupiter are briefly considered.

  18. Conduction in fully ionized liquid metals

    NASA Technical Reports Server (NTRS)

    Stevenson, D. J.; Ashcroft, N. W.

    1974-01-01

    Electron transport is considered in high-density fully ionized liquid metals. Ionic structure is described in terms of hard-sphere-correlation functions and the scattering is determined from self-consistently screened point ions. Applications to the physical properties of the deep interior of Jupiter are briefly considered.

  19. Solar-driven liquid metal magnetohydrodynamic generator

    NASA Astrophysics Data System (ADS)

    Lee, J. H.; Hohl, F.

    1981-05-01

    A solar oven heated by concentrated solar radiation as the heat source of a liquid metal magnetohydrodynamic (LMMHD) power generation system is proposed. The design allows the production of electric power in space, as well as on Earth, at high rates of efficiency. Two types of the solar oven suitable for the system are discussed.

  20. Solar-driven liquid metal magnetohydrodynamic generator

    NASA Technical Reports Server (NTRS)

    Lee, J. H.; Hohl, F.

    1981-01-01

    A solar oven heated by concentrated solar radiation as the heat source of a liquid metal magnetohydrodynamic (LMMHD) power generation system is proposed. The design allows the production of electric power in space, as well as on Earth, at high rates of efficiency. Two types of the solar oven suitable for the system are discussed.

  1. Liquid-metal-cooled reactor

    DOEpatents

    Hutter, Ernest

    1982-01-01

    A perforated depressor plate extending across the bottom of the instrument ree of a fast breeder reactor cooperates with a circular cylindrical metal bellows forming a part of the upper adapter of each core assembly and bearing on the bottom of the depressor plate to restrict flow of coolant between core assemblies, thereby reducing significantly the pressure differential between the coolant inside the core assemblies and the coolant outside of the core assemblies. Openings in the depressor plate are slightly smaller than the top of the upper adapter so the depressor plate will serve as a backup mechanical holddown for the core. In addition coolant mixing devices and locating devices are provided attached to the depressor plate.

  2. Liquid-metal-cooled reactor

    DOEpatents

    Hutter, E.

    A perforated depressor plate extending across the bottom of the instrument tree of a fast breeder reactor cooperates with a circular cylindrical metal bellows forming a part of the upper adapter of each core assembly and bearing on the bottom of the depressor plate to restrict flow of coolant between core assemblies, thereby reducing significantly the pressure differential between the coolant inside the core assemblies and the coolant outside of the core assemblies. Openings in the depressor plate are slightly smaller than the top of the upper adapter so the depressor plate will serve as a backup mechanical holddown for the core. In addition, coolant mixing devices and locating devices are provided attached to the depressor plate.

  3. Liquid crystal on subwavelength metal gratings

    NASA Astrophysics Data System (ADS)

    Palto, S. P.; Barnik, M. I.; Artemov, V. V.; Shtykov, N. M.; Geivandov, A. R.; Yudin, S. G.; Gorkunov, M. V.

    2015-06-01

    Optical and electrooptical properties of a system consisting of subwavelength metal gratings and nematic liquid crystal layer are studied. Aluminium gratings that also act as interdigitated electrodes are produced by focused ion beam lithography. It is found that a liquid crystal layer strongly influences both the resonance and light polarization properties characteristic of the gratings. Enhanced transmittance is observed not only for the TM-polarized light in the near infrared spectral range but also for the TE-polarized light in the visible range. Although the electrodes are separated by nanosized slits, and the electric field is strongly localized near the surface, a pronounced electrooptical effect is registered. The effect is explained in terms of local reorientation of liquid crystal molecules at the grating surface and propagation of the orientational deformation from the surface into the bulk of the liquid crystal layer.

  4. Liquid crystal on subwavelength metal gratings

    SciTech Connect

    Palto, S. P.; Barnik, M. I.; Artemov, V. V.; Shtykov, N. M.; Geivandov, A. R.; Yudin, S. G.; Gorkunov, M. V.

    2015-06-14

    Optical and electrooptical properties of a system consisting of subwavelength metal gratings and nematic liquid crystal layer are studied. Aluminium gratings that also act as interdigitated electrodes are produced by focused ion beam lithography. It is found that a liquid crystal layer strongly influences both the resonance and light polarization properties characteristic of the gratings. Enhanced transmittance is observed not only for the TM-polarized light in the near infrared spectral range but also for the TE-polarized light in the visible range. Although the electrodes are separated by nanosized slits, and the electric field is strongly localized near the surface, a pronounced electrooptical effect is registered. The effect is explained in terms of local reorientation of liquid crystal molecules at the grating surface and propagation of the orientational deformation from the surface into the bulk of the liquid crystal layer.

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

    DOEpatents

    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.

  6. Compact, Lightweight Electromagnetic Pump for Liquid Metal

    NASA Technical Reports Server (NTRS)

    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.

  7. Atomic Dynamics in Metallic Liquids and Glasses

    SciTech Connect

    Egami, Takeshi; Levashov, Valentin A; Aga, Rachel S; Morris, James R

    2007-01-01

    How atoms move in metallic glasses and liquids is an important question in discussing atomic transport, glass formation, structural relaxation and other properties of metallic glasses. While the concept of free-volume has long been used in describing atomic transport, computer simulations and isotope measurements have shown that atomic transport occurs by a much more collective process than assumed in the free-volume theory. We introduce a new approach to describe the atomic dynamics in metallic glasses, in terms of local energy landscapes related to fluctuations in the topology of atomic connectivity. This approach may form the basis for a new paradigm for discussing the structure-properties relationship in metallic glasses.

  8. Liquid metal pump for nuclear reactors

    DOEpatents

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

    1975-10-01

    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. Containerless thermophysical property measurements for liquid metals

    SciTech Connect

    Xiao, Z.L.; Pryor, K.E.; Hauge, R.H.; Margrave, J.L.

    1995-04-01

    Methods for measuring the thermophysical properties of liquid metals including sample size and density, translational and vibrational modes, surface tension, emissivity and thermodynamic temperature have been developed in the authors laboratory. Sample shape, size and density are measured with a video-imaging and computer processing technique. The translational and vibrational frequencies are monitored through the use of a continuous duo-lateral position sensor, where appropriate analysis of the data provides surface tension information. A two-channel polarization modulation ellipsometer has been developed to measure the optical constants and emissivity of a levitated metal drop. Preliminary results from the use of these techniques have been promising.

  10. POWER GENERATION FROM LIQUID METAL NUCLEAR FUEL

    DOEpatents

    Dwyer, O.E.

    1958-12-23

    A nuclear reactor system is described wherein the reactor is the type using a liquid metal fuel, such as a dispersion of fissile material in bismuth. The reactor is designed ln the form of a closed loop having a core sectlon and heat exchanger sections. The liquid fuel is clrculated through the loop undergoing flssion in the core section to produce heat energy and transferrlng this heat energy to secondary fluids in the heat exchanger sections. The fission in the core may be produced by a separate neutron source or by a selfsustained chain reaction of the liquid fuel present in the core section. Additional auxiliary heat exchangers are used in the system to convert water into steam which drives a turbine.

  11. Stretchable Loudspeaker using Liquid Metal Microchannel.

    PubMed

    Jin, Sang Woo; Park, Jeongwon; Hong, Soo Yeong; Park, Heun; Jeong, Yu Ra; Park, Junhong; Lee, Sang-Soo; Ha, Jeong Sook

    2015-07-16

    Considering the various applications of wearable and bio-implantable devices, it is desirable to realize stretchable acoustic devices for body-attached applications such as sensing biological signals, hearing aids, and notification of information via sound. In this study, we demonstrate the facile fabrication of a Stretchable Acoustic Device (SAD) using liquid metal coil of Galinstan where the SAD is operated by the electromagnetic interaction between the liquid metal coil and a Neodymium (Nd) magnet. To fabricate a liquid metal coil, Galinstan was injected into a micro-patterned elastomer channel. This fabricated SAD was operated simultaneously as a loudspeaker and a microphone. Measurements of the frequency response confirmed that the SAD was mechanically stable under both 50% uniaxial and 30% biaxial strains. Furthermore, 2000 repetitive applications of a 50% uniaxial strain did not induce any noticeable degradation of the sound pressure. Both voice and the beeping sound of an alarm clock were successfully recorded and played back through our SAD while it was attached to the wrist under repeated deformation. These results demonstrate the high potential of the fabricated SAD using Galinstan voice coil in various research fields including stretchable, wearable, and bio-implantable acoustic devices.

  12. Stretchable Loudspeaker using Liquid Metal Microchannel

    NASA Astrophysics Data System (ADS)

    Jin, Sang Woo; Park, Jeongwon; Hong, Soo Yeong; Park, Heun; Jeong, Yu Ra; Park, Junhong; Lee, Sang-Soo; Ha, Jeong Sook

    2015-07-01

    Considering the various applications of wearable and bio-implantable devices, it is desirable to realize stretchable acoustic devices for body-attached applications such as sensing biological signals, hearing aids, and notification of information via sound. In this study, we demonstrate the facile fabrication of a Stretchable Acoustic Device (SAD) using liquid metal coil of Galinstan where the SAD is operated by the electromagnetic interaction between the liquid metal coil and a Neodymium (Nd) magnet. To fabricate a liquid metal coil, Galinstan was injected into a micro-patterned elastomer channel. This fabricated SAD was operated simultaneously as a loudspeaker and a microphone. Measurements of the frequency response confirmed that the SAD was mechanically stable under both 50% uniaxial and 30% biaxial strains. Furthermore, 2000 repetitive applications of a 50% uniaxial strain did not induce any noticeable degradation of the sound pressure. Both voice and the beeping sound of an alarm clock were successfully recorded and played back through our SAD while it was attached to the wrist under repeated deformation. These results demonstrate the high potential of the fabricated SAD using Galinstan voice coil in various research fields including stretchable, wearable, and bio-implantable acoustic devices.

  13. Stretchable Loudspeaker using Liquid Metal Microchannel

    PubMed Central

    Jin, Sang Woo; Park, Jeongwon; Hong, Soo Yeong; Park, Heun; Jeong, Yu Ra; Park, Junhong; Lee, Sang-Soo; Ha, Jeong Sook

    2015-01-01

    Considering the various applications of wearable and bio-implantable devices, it is desirable to realize stretchable acoustic devices for body-attached applications such as sensing biological signals, hearing aids, and notification of information via sound. In this study, we demonstrate the facile fabrication of a Stretchable Acoustic Device (SAD) using liquid metal coil of Galinstan where the SAD is operated by the electromagnetic interaction between the liquid metal coil and a Neodymium (Nd) magnet. To fabricate a liquid metal coil, Galinstan was injected into a micro-patterned elastomer channel. This fabricated SAD was operated simultaneously as a loudspeaker and a microphone. Measurements of the frequency response confirmed that the SAD was mechanically stable under both 50% uniaxial and 30% biaxial strains. Furthermore, 2000 repetitive applications of a 50% uniaxial strain did not induce any noticeable degradation of the sound pressure. Both voice and the beeping sound of an alarm clock were successfully recorded and played back through our SAD while it was attached to the wrist under repeated deformation. These results demonstrate the high potential of the fabricated SAD using Galinstan voice coil in various research fields including stretchable, wearable, and bio-implantable acoustic devices. PMID:26181209

  14. Liquid-metal embrittlement of refractory metals by molten plutonium

    SciTech Connect

    Lesuer, D.R.; Bergin, J.B.; McInturff, S.A.; Kuhn, B.A.

    1980-07-01

    Embrittlement by molten plutonium of the refractory metals and alloys W-25 wt % Re, tantalum, molybdenum, and Ta-10 wt % W was studied. At 900/sup 0/C and a strain rate of 10/sup -4/ s/sup -1/, the materials tested may be ranked in order of decreasing susceptibility to liquid-plutonium embrittlement as follows: molybdenum, W-25 wt % Re, Ta-10 wt % W, and tantalum. These materials exhibited a wide range in susceptibility. Embrittlement was found to exhibit a high degree of temperature and strain-rate dependence, and we present arguments that strongly support a stress-assisted, intergranular, liquid-metal corrosion mechanism. We also believe microstructure plays a key role in the extent of embrittlement. In the case of W-25 wt % Re, we have determined that a dealloying corrosion takes place in which rhenium is selectively withdrawn from the alloy.

  15. Liquid suspensions of reversible metal hydrides

    DOEpatents

    Reilly, J.J.; Grohse, E.W.; Winsche, W.E.

    1983-12-08

    The reversibility of the process M + x/2 H/sub 2/ ..-->.. MH/sub x/, where M is a metal hydride former that forms a hydride MH/sub x/ in the presence of H/sub 2/, generally used to store and recall H/sub 2/, is found to proceed under a liquid, thereby to reduce contamination, provide better temperature control and provide in situ mobility of the reactants. Thus, a slurry of particles of a metal hydride former with an inert solvent is subjected to temperature and pressure controlled atmosphere containing H/sub 2/, to store hydrogen (at high pressures) and to release (at low pressures) previously stored hydrogen. The direction of the flow of the H/sub 2/ through the liquid is dependent upon the H/sub 2/ pressure in the gas phase at a given temperature. When the former is above the equilibrium absorption pressure of the respective hydride the reaction proceeds to the right, i.e., the metal hydride is formed and hydrogen is stored in the solid particle. When the H/sub 2/ pressure in the gas phase is below the equilibrium dissociation pressure of the respective hydride the reaction proceeds to the left, the metal hydride is decomposed and hydrogen is released into the gas phase.

  16. Prospects for advanced electron cyclotron resonance and electron beam ion source charge breeding methods for EURISOL

    SciTech Connect

    Delahaye, P.; Jardin, P.; Maunoury, L.; Traykov, E.; Varenne, F.; Angot, J.; Lamy, T.; Sortais, P.; Thuillier, T.; Ban, G.; Celona, L.; Lunney, D.; Choinski, J.; Gmaj, P.; Jakubowski, A.; Steckiewicz, O.; Kalvas, T.; and others

    2012-02-15

    As the most ambitious concept of isotope separation on line (ISOL) facility, EURISOL aims at producing unprecedented intensities of post-accelerated radioactive isotopes. Charge breeding, which transforms the charge state of radioactive beams from 1+ to an n+ charge state prior to post-acceleration, is a key technology which has to overcome the following challenges: high charge states for high energies, efficiency, rapidity and purity. On the roadmap to EURISOL, a dedicated R and D is being undertaken to push forward the frontiers of the present state-of-the-art techniques which use either electron cyclotron resonance or electron beam ion sources. We describe here the guidelines of this R and D.

  17. Modeling of thermodiffusion in liquid metal alloys.

    PubMed

    Eslamian, Morteza; Sabzi, Fatemeh; Saghir, M Ziad

    2010-11-01

    In this paper following the linear non-equilibrium thermodynamics approach, an expression is derived for the calculation of the thermodiffusion factor in binary liquid metal alloys. The expression is comprised of two terms; the first term accounts for the thermally driven interactions between metal ions, a phenomenon similar to that of the non-ionic binary mixtures, such as hydrocarbons; the second term is called the electronic contribution and is the mass diffusion due to an internal electric field that is induced as a result of the imposed thermal gradient. Both terms are formulated as functions of the net heats of transport. The ion-ion net heat of transport is simulated by the activation energy of viscous flow and the electronic net heat of transport is correlated with the force acting on the ions by the rearrangement of the conduction electrons and ions. A methodology is presented and used to estimate the liquid metal properties, such as the partial molar internal energies, enthalpies, volumes and the activity coefficients used for model validation. The prediction power of the proposed expression along with some other existing thermodiffusion models for liquid mixtures, such as the Haase, Kempers, Drickamer and Firoozabadi formulas are examined against available experimental data obtained on ground or in microgravity environment. The proposed model satisfactorily predicts the thermodiffusion data of mixtures that are composed of elements with comparable melting points. It is also potentially and qualitatively able to predict a sign change in thermodiffusion factor of Na-K liquid mixture. With some speculation, the sign change is attributed to an anomalous change in thermoelectric power of Na-K mixture with composition. PMID:20856973

  18. SP-100 liquid metal test loop design

    NASA Astrophysics Data System (ADS)

    Fallas, T. Ted; Kruger, Gordon B.; Wiltshire, Frank R.; Jensen, Grant C.; Clay, Harold; Upton, Hugh A.; Gamble, Robert E.; Kjaer-Olsen, Christian; Lee, Keith

    1992-01-01

    The SP-100 Power System Qualification (PSO) program validates the technology readiness of the SP-100 Generic Flight System (GFS). As part of the PSQ, the GFS reactor, heat transport and power generation systems are being validated, by test, in high temperature liquid metal test loops. The liquid metal test loop program consists of two test loops. The first, a natural circulation material test loop (MTL), has been successfully operating for the last year at GE's test facility in San Jose. The second, a forced circulation Component Test Loop (CTL) is in the preliminary design phase. Fabrication of the CTL and modifications to the Test Facility will be completed in FY94 with component testing scheduled to begin in FY95. The CTL is a Nb-1Zr test loop with an Electromagnetic (EM) pump providing forced circulation for the liquid lithium coolant. The CTL test program is comprised of a series of individual component tests. Test components containing thermoelectric cells will have their cold side ducts piped to an existing heat rejection loop external to the CTL vacuum vessel. The test assembly and test components are being designed by GE. The detail design of several loop components is being performed by Westinghouse Atomic Energy Systems (WAES). The CTL will be assembled and the test performed at GE's facilties in San Jose, California.

  19. Magnetic-field-induced liquid metal droplet manipulation

    NASA Astrophysics Data System (ADS)

    Kim, Daeyoung; Lee, Jeong-Bong

    2015-01-01

    We report magnetic-field-induced liquid metal droplet on-demand manipulation by coating a liquid metal with ferromagnetic materials. The gallium-based liquid metal alloy has a challenging drawback that it is instantly oxidized in ambient air, resulting in surface wetting on most surfaces. When the oxidized surface of the droplet is coated with ferromagnetic materials, it is non-wettable and can be controlled by applying an external magnetic field. We coated the surface of a liquid metal droplet with either an electroplated CoNiMnP layer or an iron (Fe) particle by simply rolling the liquid metal droplet on an Fe particle bed. For a paper towel, the minimum required magnetic flux density to initiate movement of the ~8 μL Fe-particle-coated liquid metal droplet was 50 gauss. Magnetic-field-induced liquid metal droplet manipulation was investigated under both horizontal and vertical magnetic fields. Compared to the CoNiMnP-electroplated liquid metal droplet, the Fe-particle-coated droplet could be well controlled because Fe particles were uniformly coated on the surface of the droplet. With a maximum applied magnetic flux density of ~1,600 gauss, the CoNiMnP layer on the liquid metal broke down, resulting in fragmentation of three smaller droplets, and the Fe particle was detached from the liquid metal surface and was re-coated after the magnetic field had been removed.

  20. Detection of velocity in high temperature liquid metals

    NASA Technical Reports Server (NTRS)

    Mikrovas, A. C.; Argyropoulos, S. A.

    1993-01-01

    Various efforts have been made to measure velocity in liquid metals. All of these efforts, however, share the same inherent limitation, namely, not being operative at the high temperatures required by liquid metals and liquid slags in an industrial application. In this paper, the current methods used were reviewed, and a new technique was presented for the measurement of velocity in high temperature liquid metals. In using this technique there are two stages. Starting with the calibration stage and then moving to the actual measurement stage by making use of the data obtained from calibration stage. Calibration proceeds in the following manner. Metallic spheres moving with a specific velocity are immersed in liquid metal held under isothermal conditions and at specific temperature. Their melting times are determined very accurately with a novel technique. These measurements are repeated for different metal bath temperatures and for different velocities of metallic spheres. In this manner it is possible to calculate the correlation between velocity and melting times for each metal bath temperature. During the actual measurement stage, when the metal bath temperature is known and its velocity is unknown, the magnitude of the unknown liquid metal velocity can be derived as follows: metallic spheres are immersed into the moving liquid metal and their melting times are determined. Using the above mentioned correlations, it will be shown that the magnitude of the unknown velocity in liquid metal can be deduced. This new technique was applied to high temperature liquid aluminum and liquid steel and these results were presented. The potential applicability of this technique in other liquid metals and liquid slags will also be discussed.

  1. Liquid oxygen/metal gelled monopropellants

    NASA Technical Reports Server (NTRS)

    Wickman, John H.

    1991-01-01

    The objectives of this program were to establish the feasibility of metallized/liquid oxygen monopropellants and select the best monopropellant formulation for continued study. The metal powders mixed with the liquid oxygen were aluminum/magnesium (80/20), silicon and iron (Iron was only tested for burning properties). The formulations were first evaluated on whether they detonated when ignited or burned. The formulations only burned when ignited. The viscosity for the formulations ranged from 900 cps to 100 cps at shear rates up to 300 seconds(sup -1). Two percent (by weight) of Cab-O-Sil was added to the aluminum and aluminum/magnesium formulations for gelling while the silicon formulation used three percent. Within a seven hour period, settling was suggested only in the 29 percent aluminum and 29 percent aluminum/magnesium formulations. The monopropellants were burned in a cylinder submerged in a liquid nitrogen bath. Experimental data at ambient pressure indicated that the monopropellants were extinguished when the flame front reached regions submerged under the liquid nitrogen. The burn rate increased dramatically when burned in a cylinder enclosure with less heat sink available to the monopropellant. The test results were inconclusive as to whether the increased burn rate was due to the lower heat sink capacity or the small amount of pressure (2 psi) generated during the burning of the monopropellant. The burning of the aluminum and aluminum/magnesium resulted in a brilliant white flame similar to that of an arc welder. These monopropellants burned in a pulsating manner with the aluminum/magnesium appearing to have less pulsating combustion. The silicon monopropellant burned with an orange glow. No sparks or energetic burning was apparent as with the aluminum or aluminum/magnesium.

  2. Thermal convection in a liquid metal battery

    NASA Astrophysics Data System (ADS)

    Shen, Yuxin; Zikanov, Oleg

    2016-08-01

    Generation of thermal convection flow in the liquid metal battery, a device recently proposed as a promising solution for the problem of the short-term energy storage, is analyzed using a numerical model. It is found that convection caused by Joule heating of electrolyte during charging or discharging is virtually unavoidable. It exists in laboratory prototypes larger than a few centimeters in size and should become much stronger in larger-scale batteries. The phenomenon needs further investigation in view of its positive (enhanced mixing of reactants) and negative (loss of efficiency and possible disruption of operation due to the flow-induced deformation of the electrolyte layer) effects.

  3. Liquid metal nanodroplet dynamics inside nanocontainers

    PubMed Central

    Jung, Hyun Young; Chun, Hyunkyung; Park, Sora; Kang, Seoung-Hun; Ahn, Chi Won; Kwon, Young-Kyun; Upmanyu, Moneesh; Ajayan, Pulickel M.; Jung, Yung Joon

    2013-01-01

    Here we report direct observations of spatial movements of nanodroplets of Pb metal trapped inside sealed carbon nanocontainers. We find drastic changes in the mobility of the liquid droplets as the particle size increases from a few to a few ten nanometers. In open containers the droplet becomes immobile and readily evaporates to the vacuum environment. The particle mobility strongly depends on confinement, particle size, and wetting on the enclosed surface. The collisions between droplets increase mobility but the tendency is reversed if collisions lead to droplet coalescence. The dynamics of confined nanodroplets could provide new insights into the activity of nanostructures in spatially constrained geometries. PMID:24005021

  4. Power losses in liquid metal current collectors

    NASA Astrophysics Data System (ADS)

    Hurwitz, M. M.; Wallace, D. R.

    1980-05-01

    A numerical capability has been developed which will compute ohmic and viscous power losses in liquid metal current collectors. The present work extends previous analytical investigations in that semi-infinite collector geometries are no longer assumed. This new capability is based on the finite element method and makes use of electrical current densities computed by the heat transfer portion of the NASTRAN structural analysis program. Although some limitations and questions remain, a comparison between the new numerical capability and experiment shows very good agreement in the computation of the power losses.

  5. Process for preparing liquid metal electrical contact device

    NASA Technical Reports Server (NTRS)

    Lovell, R. R.; Berkopec, F. D.; Culp, D. H. (Inventor)

    1977-01-01

    The parts of an electrical contact device are treated by sputter etching to remove the parent metal oxide. Prior to exposure of the electrodes to any oxygen, a sacrificial metal is sputter deposited on the parts. Preferably this sacrificial metal is one that oxidizes slowly and is readily dissolved by the liquid metal. The sacrificial metal may then be removed from unwanted areas. The remainder of the ring and the probe to be wet by the liquid metal are submerged in the liquid metal or the liquid metal is flushed over these areas, preferably while they are being slightly abraded, unitl all the sacrificial material on these portions is wet by the liquid metal. In doing so the liquid metal dissolves the sacrificial metal and permanently wets the parent metal. Preferred materials used in the process and for the electrodes of electrical contact devices are high purity (99.0%) nickel or AISI type 304 stainless steel for the electrical contact devices, gallium as the liquid metal, and gold as the sacrificial material.

  6. Metal-ion-ligand interactions in thermotropic liquid crystals

    NASA Astrophysics Data System (ADS)

    Diehl, P.; Wasser, H. R.; Gowda, G. A. Nagana; Suryaprakash, N.; Khetrapal, C. L.

    1989-07-01

    The interactions of lithium perchlorate with ligands such as dimethyl sulphoxide, acetonitrile, pyridine and the Schiff base liquid crystals are investigated. The experiments open a new field for the study of metal-ion-ligand interactions in thermotropic liquid crystals.

  7. Slow Modes in Convecting Liquid Metal

    NASA Astrophysics Data System (ADS)

    Aurnou, J. M.; Ribeiro, A.; Calkins, M. A.; Julien, K. A.

    2015-12-01

    Slow, large-scale magnetostrophic wave modes are expected to develop in rapidly-rotating magnetohydrodynamic systems. These slow modes arise due to a leading order balance between Coriolis and Lorentz forces, with negligible effects of fluid inertia. Such slow modes have long been argued to be the primary cause of the long period (e.g., century-scale) variations in observations of the geomagnetic field. Yet, to date, such slow modes have yet to develop in global-scale numerical models of planetary dynamo action. Here we present the results of closely coupled laboratory-numerical simulations of rapidly rotating magnetoconvection in liquid gallium, in which we find strong evidence for slow modes developing near, as well as beyond, the onset of convection. Preliminary results from an associated survey of numerical simulations are allowing us to determine under what range of conditions slow convective modes exist. Thus far, it appears they develop only in low Prandtl number fluids, in which the thermal diffusivity significantly exceeds the viscous diffusivity, as occurs in liquid metals. Our findings suggest more metal-like fluid properties are necessary for the development of slow modes in convection-driven global-scale dynamo models.

  8. Diverse transformations of liquid metals between different morphologies.

    PubMed

    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. PMID:24889178

  9. High-Power Liquid-Metal Heat-Transfer Loop

    NASA Technical Reports Server (NTRS)

    Bhandari, Pradeep; Fujita, Toshio

    1991-01-01

    Proposed closed-loop system for transfer of thermal power operates at relatively high differential pressure between vapor and liquid phases of liquid-metal working fluid. Resembles "capillary-pumped" liquid-metal heat-transfer loop except electric field across permselective barrier of beta alumina keeps liquid and vapor separate at heat-input end. Increases output thermal power, contains no moving parts, highly reliable and well suited to long-term unattended operation.

  10. Small Liquid Metal Cooled Reactor Safety Study

    SciTech Connect

    Minato, A; Ueda, N; Wade, D; Greenspan, E; Brown, N

    2005-11-02

    The Small Liquid Metal Cooled Reactor Safety Study documents results from activities conducted under Small Liquid Metal Fast Reactor Coordination Program (SLMFR-CP) Agreement, January 2004, between the Central Research Institute of the Electric Power Industry (CRIEPI) of Japan and the Lawrence Livermore National Laboratory (LLNL)[1]. Evaluations were completed on topics that are important to the safety of small sodium cooled and lead alloy cooled reactors. CRIEPI investigated approaches for evaluating postulated severe accidents using the CANIS computer code. The methods being developed are improvements on codes such as SAS 4A used in the US to analyze sodium cooled reactors and they depend on calibration using safety testing of metal fuel that has been completed in the TREAT facility. The 4S and the small lead cooled reactors in the US are being designed to preclude core disruption from all mechanistic scenarios, including selected unprotected transients. However, postulated core disruption is being evaluated to support the risk analysis. Argonne National Laboratory and the University of California Berkeley also supported LLNL with evaluation of cores with small positive void worth and core designs that would limit void worth. Assessments were also completed for lead cooled reactors in the following areas: (1) continuing operations with cladding failure, (2) large bubbles passing through the core and (3) recommendations concerning reflector control. The design approach used in the US emphasizes reducing the reactivity in the control mechanisms with core designs that have essentially no, or a very small, reactivity change over the core life. This leads to some positive void worth in the core that is not considered to be safety problem because of the inability to identify scenarios that would lead to voiding of lead. It is also believed that the void worth will not dominate the severe accident analysis. The approach used by 4S requires negative void worth throughout

  11. Liquid metal cooled reactors for space power applications

    NASA Technical Reports Server (NTRS)

    Bailey, S.; Vaidyanathan, S.; Van Hoomissen, J.

    1985-01-01

    The technology basis for evaluation of liquid metal cooled space reactors is summarized. Requirements for space nuclear power which are relevant to selection of the reactor subsystem are then reviewed. The attributes of liquid metal cooled reactors are considered in relation to these requirements in the areas of liquid metal properties, neutron spectrum characteristics, and fuel form. Key features of typical reactor designs are illustrated. It is concluded that liquid metal cooled fast spectrum reactors provide a high confidence, flexible option for meeting requirements for SP-100 and beyond.

  12. Dynamic interactions of Leidenfrost droplets on liquid metal surface

    NASA Astrophysics Data System (ADS)

    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.

  13. Self-Actuation of Liquid Metal via Redox Reaction.

    PubMed

    Gough, Ryan C; Dang, Jonathan H; Moorefield, Matthew R; Zhang, George B; Hihara, Lloyd H; Shiroma, Wayne A; Ohta, Aaron T

    2016-01-13

    Presented here is a method for actuating a gallium-based liquid-metal alloy without the need for an external power supply. Liquid metal is used as an anode to drive a complementary oxygen reduction reaction, resulting in the spontaneous growth of hydrophilic gallium oxide on the liquid-metal surface, which induces flow of the liquid metal into a channel. The extent and duration of the actuation are controllable throughout the process, and the induced flow is both reversible and repeatable. This self-actuation technique can also be used to trigger other electrokinetic or fluidic mechanisms. PMID:26693856

  14. Self-Actuation of Liquid Metal via Redox Reaction.

    PubMed

    Gough, Ryan C; Dang, Jonathan H; Moorefield, Matthew R; Zhang, George B; Hihara, Lloyd H; Shiroma, Wayne A; Ohta, Aaron T

    2016-01-13

    Presented here is a method for actuating a gallium-based liquid-metal alloy without the need for an external power supply. Liquid metal is used as an anode to drive a complementary oxygen reduction reaction, resulting in the spontaneous growth of hydrophilic gallium oxide on the liquid-metal surface, which induces flow of the liquid metal into a channel. The extent and duration of the actuation are controllable throughout the process, and the induced flow is both reversible and repeatable. This self-actuation technique can also be used to trigger other electrokinetic or fluidic mechanisms.

  15. Recent applications of liquid metals featuring nanoscale surface oxides

    NASA Astrophysics Data System (ADS)

    Neumann, Taylor V.; Dickey, Michael D.

    2016-05-01

    This proceeding describes recent efforts from our group to control the shape and actuation of liquid metal. The liquid metal is an alloy of gallium and indium which is non-toxic, has negligible vapor pressure, and develops a thin, passivating surface oxide layer. The surface oxide allows the liquid metal to be patterned and shaped into structures that do not minimize interfacial energy. The surface oxide can be selectively removed by changes in pH or by applying a voltage. The surface oxide allows the liquid metal to be 3D printed to form free-standing structures. It also allows for the liquid metal to be injected into microfluidic channels and to maintain its shape within the channels. The selective removal of the oxide results in drastic changes in surface tension that can be used to control the flow behavior of the liquid metal. The metal can also wet thin, solid films of metal that accelerates droplets of the liquid along the metal traces .Here we discuss the properties and applications of liquid metal to make soft, reconfigurable electronics.

  16. Steering liquid metal flow in microchannels using low voltages.

    PubMed

    Tang, Shi-Yang; Lin, Yiliang; Joshipura, Ishan D; Khoshmanesh, Khashayar; Dickey, Michael D

    2015-10-01

    Liquid metals based on gallium, such as eutectic gallium indium (EGaIn) and Galinstan, have been integrated as static components in microfluidic systems for a wide range of applications including soft electrodes, pumps, and stretchable electronics. However, there is also a possibility to continuously pump liquid metal into microchannels to create shape reconfigurable metallic structures. Enabling this concept necessitates a simple method to control dynamically the path the metal takes through branched microchannels with multiple outlets. This paper demonstrates a novel method for controlling the directional flow of EGaIn liquid metal in complex microfluidic networks by simply applying a low voltage to the metal. According to the polarity of the voltage applied between the inlet and an outlet, two distinct mechanisms can occur. The voltage can lower the interfacial tension of the metal via electrocapillarity to facilitate the flow of the metal towards outlets containing counter electrodes. Alternatively, the voltage can drive surface oxidation of the metal to form a mechanical impediment that redirects the movement of the metal towards alternative pathways. Thus, the method can be employed like a 'valve' to direct the pathway chosen by the metal without mechanical moving parts. The paper elucidates the operating mechanisms of this valving system and demonstrates proof-of-concept control over the flow of liquid metal towards single or multiple directions simultaneously. This method provides a simple route to direct the flow of liquid metal for applications in microfluidics, optics, electronics, and microelectromechanical systems.

  17. Steering liquid metal flow in microchannels using low voltages.

    PubMed

    Tang, Shi-Yang; Lin, Yiliang; Joshipura, Ishan D; Khoshmanesh, Khashayar; Dickey, Michael D

    2015-10-01

    Liquid metals based on gallium, such as eutectic gallium indium (EGaIn) and Galinstan, have been integrated as static components in microfluidic systems for a wide range of applications including soft electrodes, pumps, and stretchable electronics. However, there is also a possibility to continuously pump liquid metal into microchannels to create shape reconfigurable metallic structures. Enabling this concept necessitates a simple method to control dynamically the path the metal takes through branched microchannels with multiple outlets. This paper demonstrates a novel method for controlling the directional flow of EGaIn liquid metal in complex microfluidic networks by simply applying a low voltage to the metal. According to the polarity of the voltage applied between the inlet and an outlet, two distinct mechanisms can occur. The voltage can lower the interfacial tension of the metal via electrocapillarity to facilitate the flow of the metal towards outlets containing counter electrodes. Alternatively, the voltage can drive surface oxidation of the metal to form a mechanical impediment that redirects the movement of the metal towards alternative pathways. Thus, the method can be employed like a 'valve' to direct the pathway chosen by the metal without mechanical moving parts. The paper elucidates the operating mechanisms of this valving system and demonstrates proof-of-concept control over the flow of liquid metal towards single or multiple directions simultaneously. This method provides a simple route to direct the flow of liquid metal for applications in microfluidics, optics, electronics, and microelectromechanical systems. PMID:26279150

  18. Reconfigurable plasmonic devices using liquid metals.

    PubMed

    Wang, Jinqi; Liu, Shuchang; Nahata, Ajay

    2012-05-21

    We experimentally demonstrate an approach to create reconfigurable plasmonic devices in which the geometry of the device can be changed dramatically. The specific embodiment we present utilizes eutectic gallium indium (EGaIn), a metal that is liquid at room temperature, which is injected into or withdrawn from channels encapsulated by a polydimethylsiloxane (PDMS) bullseye mold fabricated on a gold coated substrate. Using terahertz (THz) time-domain spectroscopy, we measure the enhanced transmission properties of a single subwavelength aperture surrounded by differing numbers of concentric annular EGaIn rings. The results obtained from different device geometries, with either a single or multiple rings, are performed using a single device, demonstrating true reconfigurability. We explain the properties of the observed temporal waveforms using a simple time-domain model. This represents, we believe, a first step in developing more complex reconfigurable plasmonic devices.

  19. Impact dynamics of oxidized liquid metal drops

    NASA Astrophysics Data System (ADS)

    Xu, Qin; Brown, Eric; Jaeger, Heinrich M.

    2013-04-01

    With exposure to air, many liquid metals spontaneously generate an oxide layer on their surface. In oscillatory rheological tests, this skin is found to introduce a yield stress that typically dominates the elastic response but can be tuned by exposing the metal to hydrochloric acid solutions of different concentration. We systematically studied the normal impact of eutectic gallium-indium (eGaIn) drops under different oxidation conditions and show how this leads to two different dynamical regimes. At low impact velocity (or low Weber number), eGaIn droplets display strong recoil and rebound from the impacted surface when the oxide layer is removed. In addition, the degree of drop deformation or spreading during impact is controlled by the oxide skin. We show that the scaling law known from ordinary liquids for the maximum spreading radius as a function of impact velocity can still be applied to the case of oxidized eGaIn if an effective Weber number We is employed that uses an effective surface tension factoring in the yield stress. In contrast, no influence on spreading from different oxidations conditions is observed for high impact velocity. This suggests that the initial kinetic energy is mostly damped by bulk viscous dissipation. Results from both regimes can be collapsed in an impact phase diagram controlled by two variables, the maximum spreading factor Pm=R0/Rm, given by the ratio of initial to maximum drop radius, and the impact number K=We/Re4/5, which scales with the effective Weber number We as well as the Reynolds number Re. The data exhibit a transition from capillary to viscous behavior at a critical impact number Kc≈0.1.

  20. Heavy liquid metals: Research programs at PSI

    SciTech Connect

    Takeda, Y.

    1996-06-01

    The author describes work at PSI on thermohydraulics, thermal shock, and material tests for mechnical properties. In the presentation, the focus is on two main programs. (1) SINQ LBE target: The phase II study program for SINQ is planned. A new LBE loop is being constructed. The study has the following three objectives: (a) Pump study - design work on an electromagnetic pump to be integrated into the target. (b) Heat pipe performance test - the use of heat pipes as an additional component of the target cooling system is being considered, and it may be a way to futher decouple the liquid metal and water coolant loops. (c) Mixed convection experiment - in order to find an optimal configuration of the additional flow guide for window cooling, mixed convection around the window is to be studied. The experiment will be started using water and then with LBE. (2) ESS Mercury target: For ESS target study, the following experimental studies are planned, some of which are exampled by trial experiments. (a) Flow around the window: Flow mapping around the hemi-cylindrical window will be made for optimising the flow channels and structures, (b) Geometry optimisation for minimizing a recirculation zone behind the edge of the flow separator, (c) Flow induced vibration and buckling problem for a optimised structure of the flow separator and (d) Gas-liquid two-phase flow will be studied by starting to establish the new experimental method of measuring various kinds of two-phase flow characteristics.

  1. Theory of the spin-1 bosonic liquid metal - Equilibrium properties of liquid metallic deuterium

    NASA Technical Reports Server (NTRS)

    Oliva, J.; Ashcroft, N. W.

    1984-01-01

    The theory of a two-component quantum fluid comprised of spin-1/2 fermions and nonzero spin bosons is examined. This system is of interest because it embodies a possible quantum liquid metallic phase of highly compressed deuterium. Bose condensation is assumed present and the two cases of nuclear-spin-polarized and -unpolarized systems are considered. A significant feature in the unpolarized case is the presence of a nonmagnetic mode with quadratic dispersion owing its existence to nonzero boson spin. The physical character of this mode is examined in detail within a Bogoliubov approach. The specific heat, bulk modulus, spin susceptibility, and thermal expansion are all determined. Striking contrasts in the specific heats and thermal-expansion coefficients of the liquid and corresponding normal solid metallic phase are predicted.

  2. 3D printing of free standing liquid metal microstructures.

    PubMed

    Ladd, Collin; So, Ju-Hee; Muth, John; Dickey, Michael D

    2013-09-25

    This paper describes a method to direct-write 3D liquid metal microcomponents at room temperature. The thin oxide layer on the surface of the metal allows the formation of mechanically stable structures strong enough to stand against gravity and the large surface tension of the liquid. The method is capable of printing wires, arrays of spheres, arches, and interconnects. PMID:23824583

  3. New physics of metals: fermi surfaces without Fermi liquids.

    PubMed Central

    Anderson, P W

    1995-01-01

    I relate the historic successes, and present difficulties, of the renormalized quasiparticle theory of metals ("AGD" or Fermi liquid theory). I then describe the best-understood example of a non-Fermi liquid, the normal metallic state of the cuprate superconductors. PMID:11607559

  4. Formation of monatomic metallic glasses through ultrafast liquid quenching.

    PubMed

    Zhong, Li; Wang, Jiangwei; Sheng, Hongwei; Zhang, Ze; Mao, Scott X

    2014-08-14

    It has long been conjectured that any metallic liquid can be vitrified into a glassy state provided that the cooling rate is sufficiently high. Experimentally, however, vitrification of single-element metallic liquids is notoriously difficult. True laboratory demonstration of the formation of monatomic metallic glass has been lacking. Here we report an experimental approach to the vitrification of monatomic metallic liquids by achieving an unprecedentedly high liquid-quenching rate of 10(14) K s(-1). Under such a high cooling rate, melts of pure refractory body-centred cubic (bcc) metals, such as liquid tantalum and vanadium, are successfully vitrified to form metallic glasses suitable for property interrogations. Combining in situ transmission electron microscopy observation and atoms-to-continuum modelling, we investigated the formation condition and thermal stability of the monatomic metallic glasses as obtained. The availability of monatomic metallic glasses, being the simplest glass formers, offers unique possibilities for studying the structure and property relationships of glasses. Our technique also shows great control over the reversible vitrification-crystallization processes, suggesting its potential in micro-electromechanical applications. The ultrahigh cooling rate, approaching the highest liquid-quenching rate attainable in the experiment, makes it possible to explore the fast kinetics and structural behaviour of supercooled metallic liquids within the nanosecond to picosecond regimes.

  5. Contactless Inductive Bubble Detection in a Liquid Metal Flow

    PubMed Central

    Gundrum, Thomas; Büttner, Philipp; Dekdouk, Bachir; Peyton, Anthony; Wondrak, Thomas; Galindo, Vladimir; Eckert, Sven

    2016-01-01

    The detection of bubbles in liquid metals is important for many technical applications. The opaqueness and the high temperature of liquid metals set high demands on the measurement system. The high electrical conductivity of the liquid metal can be exploited for contactless methods based on electromagnetic induction. We will present a measurement system which consists of one excitation coil and a pickup coil system on the opposite sides of the pipe. With this sensor we were able to detect bubbles in a sodium flow inside a stainless steel pipe and bubbles in a column filled with a liquid Gallium alloy. PMID:26751444

  6. Contactless Inductive Bubble Detection in a Liquid Metal Flow.

    PubMed

    Gundrum, Thomas; Büttner, Philipp; Dekdouk, Bachir; Peyton, Anthony; Wondrak, Thomas; Galindo, Vladimir; Eckert, Sven

    2016-01-01

    The detection of bubbles in liquid metals is important for many technical applications. The opaqueness and the high temperature of liquid metals set high demands on the measurement system. The high electrical conductivity of the liquid metal can be exploited for contactless methods based on electromagnetic induction. We will present a measurement system which consists of one excitation coil and a pickup coil system on the opposite sides of the pipe. With this sensor we were able to detect bubbles in a sodium flow inside a stainless steel pipe and bubbles in a column filled with a liquid Gallium alloy. PMID:26751444

  7. Tokamak with liquid metal for inducing toroidal electrical field

    DOEpatents

    Ohkawa, Tihiro

    1981-01-01

    A tokamak apparatus includes a vessel for defining a reservoir and confining liquid therein. A toroidal liner disposed within said vessel defines a toroidal space within the liner confines gas therein. Liquid metal fills the reservoir outside the liner. A magnetic field is established in the liquid metal to develop magnetic flux linking the toroidal space. The gas is ionized. The liquid metal and the toroidal space are moved relative to one another transversely of the space to generate electric current in the ionized gas in the toroidal space about its major axis and thereby heat plasma developed in the toroidal space.

  8. Microfluidic platforms for gallium-based liquid metal alloy

    NASA Astrophysics Data System (ADS)

    Kim, Daeyoung

    As an alternative to toxic mercury, non-toxic gallium-based liquid metal alloy has been gaining popularity due to its higher thermal and electrical conductivities, and low toxicity along with liquid property. However, it is difficult to handle as the alloy becomes readily oxidized in atmospheric air environment. This instant oxidation causes the gallium-based liquid metal alloy to wet almost any solid surface. Therefore, it has been primarily limited to applications which rely only on its deformability, not on its mobility. In this research, various approaches to mobilize gallium-based liquid metal alloy were investigated. Multi-scale surface patterned with polydimethylsiloxane (PDMS) micro pillar array showed super-lyophobic property against gallium-based liquid metal alloy by minimizing the contact area between the solid surface and the liquid metal, and it was expanded to a three-dimensional tunnel shaped microfluidic channel. Vertically-aligned carbon nanotube forest leads to another promising super-lyophobic surface due to its hierarchical micro/nano scale combined structures and chemical inertness. When the carbon nanotubes were transferred onto flexible PDMS by imprinting, the super-lyophobic property was still maintained even under the mechanical deformation such as stretching and bending. Alternatively, the gallium-based liquid metal can be manipulated by modifying the surface of liquid metal itself. With chemical reaction with HCl 'vapor', the oxidized surface (mainly Ga2O3/Ga2O) of gallium-based liquid metal was converted to GaCl3/InCl 3 resulting in the recovery of non-wetting characteristics. Paper which is intrinsically porous is attractive as a super-lyophobic surface and it was found that hydrochloric acid (HCl) impregnation enhanced the anti-wetting property by the chemical reaction. As another alternative method, by coating the viscoelastic oxidized surface of liquid metal with ferromagnetic materials (CoNiMnP or Fe), it showed non

  9. Measurement of the differential pressure of liquid metals

    DOEpatents

    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)

  10. Ionic imbalance induced self-propulsion of liquid metals

    NASA Astrophysics Data System (ADS)

    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. Ionic imbalance induced self-propulsion of liquid metals

    PubMed Central

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

    2016-01-01

    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. PMID:27488954

  12. Ionic imbalance induced self-propulsion of liquid metals.

    PubMed

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

    2016-01-01

    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. PMID:27488954

  13. Ionic imbalance induced self-propulsion of liquid metals.

    PubMed

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

    2016-08-04

    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.

  14. Effects of water in film boiling over liquid metal melts

    SciTech Connect

    Greene, G.A.; Finfrock, C.; Burson, S.B.

    1986-01-01

    Liquid-liquid boiling experiments have been performed with H/sub 2/O and liquid metal melts in the 100-series test matrix (Runs 121, 126, 127) and the VE test matrix. Some of the pre-explosion unstable film boiling data as well as observations from the explosive series have been previously reported.

  15. Optical and thermodynamic property measurements of liquid metals and alloys

    NASA Technical Reports Server (NTRS)

    Weber, J. K. R.; Krishnan, Shankar; Schiffman, Robert A.; Nordine, Paul C.

    1991-01-01

    Optical properties and spectral emissivities of liquid silicon, titanium, niobium, and zirconium were investigated by HeNe laser polarimetry at 632.8 nm. The metals were of a high purity and, except for zirconium, clean. The more demanding environmental requirements for eliminating oxide or nitride phases from zirconium were not met. Containerless conditions were achieved by electromagnetic levitation and heating. CO2 laser beam heating was also used to extend the temperature range for stable levitation and to heat solid silicon to form the metallic liquid phase. Corrections to previously reported calorimetric measurements of the heat capacity of liquid niobium were derived from the measured temperature dependence of its spectral emissivity. Property measurements were obtained for supercooled liquid silicon and supercooling of liquid zirconium was accomplished. The purification of liquid metals and the extension of this work on liquids to the measurement of thermodynamic properties and phase equilibria are discussed.

  16. Solar-Driven Liquid-Metal MHD Generator

    NASA Technical Reports Server (NTRS)

    Hohl, F.; Lee, J. H.

    1982-01-01

    Liquid-metal magnetohydrodynamic (MHD) power generator with solar oven as its heat source has potential to produce electric power in space and on Earth at high efficiency. Generator focuses radiation from Sun to heat driving gas that pushes liquid metal past magnetic coil. Power is extracted directly from electric currents set up in conducting liquid. Using solar energy as fuel can save considerable costs and payload weight, compared to previous systems.

  17. Liquid metal actuation by electrical control of interfacial tension

    NASA Astrophysics Data System (ADS)

    Eaker, Collin B.; Dickey, Michael D.

    2016-09-01

    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.

  18. Hydrogenation of coal liquid utilizing a metal carbonyl catalyst

    DOEpatents

    Feder, Harold M.; Rathke, Jerome W.

    1979-01-01

    Coal liquid having a dissolved transition metal, catalyst as a carbonyl complex such as Co.sub.2 (CO.sub.8) is hydrogenated with hydrogen gas or a hydrogen donor. A dissociating solvent contacts the coal liquid during hydrogenation to form an immiscible liquid mixture at a high carbon monoxide pressure. The dissociating solvent, e.g. ethylene glycol, is of moderate coordinating ability, while sufficiently polar to solvate the transition metal as a complex cation along with a transition metal, carbonyl anion in solution at a decreased carbon monoxide pressure. The carbon monoxide pressure is reduced and the liquids are separated to recover the hydrogenated coal liquid as product. The dissociating solvent with the catalyst in ionized form is recycled to the hydrogenation step at the elevated carbon monoxide pressure for reforming the catalyst complex within fresh coal liquid.

  19. Structural disorder in metallic glass-forming liquids.

    PubMed

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

    2016-01-01

    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. PMID:27278113

  20. Structural disorder in metallic glass-forming liquids

    PubMed Central

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

    2016-01-01

    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. PMID:27278113

  1. Reconfigurable liquid metal circuits by Laplace pressure shaping

    NASA Astrophysics Data System (ADS)

    Cumby, Brad L.; Hayes, Gerard J.; Dickey, Michael D.; Justice, Ryan S.; Tabor, Christopher E.; Heikenfeld, Jason C.

    2012-10-01

    We report reconfigurable circuits formed by liquid metal shaping with <10 pounds per square inch (psi) Laplace and vacuum pressures. Laplace pressure drives liquid metals into microreplicated trenches, and upon release of vacuum, the liquid metal dewets into droplets that are compacted to 10-100× less area than when in the channel. Experimental validation includes measurements of actuation speeds exceeding 30 cm/s, simple erasable resistive networks, and switchable 4.5 GHz antennas. Such capability may be of value for next generation of simple electronic switches, tunable antennas, adaptive reflectors, and switchable metamaterials.

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

    SciTech Connect

    Zhang, D. W.; Wang, X. D. E-mail: jiangjz@zju.edu.cn; Lou, H. B.; Cao, Q. P.; Jiang, J. Z. E-mail: jiangjz@zju.edu.cn; Wang, L. W.; Zhang, D. X.

    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.

  3. Structural crossover in a supercooled metallic liquid and the link to a liquid-to-liquid phase transition

    NASA Astrophysics Data System (ADS)

    Lan, S.; Blodgett, M.; Kelton, K. F.; Ma, J. L.; Fan, J.; Wang, X.-L.

    2016-05-01

    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.

  4. Liquid Metal Cooled Reactor for Space Power

    NASA Astrophysics Data System (ADS)

    Weitzberg, Abraham

    2003-01-01

    The conceptual design is for a liquid metal (LM) cooled nuclear reactor that would provide heat to a closed Brayton cycle (CBC) power conversion subsystem to provide electricity for electric propulsion thrusters and spacecraft power. The baseline power level is 100 kWe to the user. For long term power generation, UN pin fuel with Nb1Zr alloy cladding was selected. As part of the SP-100 Program this fuel demonstrated lifetime with greater than six atom percent burnup, at temperatures in the range of 1400-1500 K. The CBC subsystem was selected because of the performance and lifetime database from commercial and aircraft applications and from prior NASA and DOE space programs. The high efficiency of the CBC also allows the reactor to operate at relatively low power levels over its 15-year life, minimizing the long-term power density and temperature of the fuel. The scope of this paper is limited to only the nuclear components that provide heated helium-xenon gas to the CBC subsystem. The principal challenge for the LM reactor concept was to design the reactor core, shield and primary heat transport subsystems to meet mission requirements in a low mass configuration. The LM concept design approach was to assemble components from prior programs and, with minimum change, determine if the system met the objective of the study. All of the components are based on technologies having substantial data bases. Nuclear, thermalhydraulic, stress, and shielding analyses were performed using available computer codes. Neutronics issues included maintaining adequate operating and shutdown reactivities, even under accident conditions. Thermalhydraulic and stress analyses calculated fuel and material temperatures, coolant flows and temperatures, and thermal stresses in the fuel pins, components and structures. Using conservative design assumptions and practices, consistent with the detailed design work performed during the SP-100 Program, the mass of the reactor, shield, primary heat

  5. Investigation of a liquid-metal magnetohydrodynamic power system.

    NASA Technical Reports Server (NTRS)

    Elliott, D. G.; Hays, L. G.; Cerini, D. J.; Bogdanoff, D. W.

    1972-01-01

    Liquid-metal magnetohydrodynamic power conversion is being investigated for nuclear-electric propulsion. A liquid-metal MHD converter has no moving mechanical parts and requires a heat source temperature of only 1300 K. Cycle efficiencies of 5% to 8% for single-stage converters and 10% for multistage converters appear attainable. The specific weight of a 240 kWe MHD power plant has been estimated as 30 kg/kWe with shielding for unmanned science missions.

  6. Analysis of liquid metal embrittlement from a bond energy viewpoint

    NASA Technical Reports Server (NTRS)

    Kelley, M. J.; Stoloff, N. S.

    1975-01-01

    Absorption induced embrittlement of solid metals by certain liquid metals is analyzed through an Engel-Brewer calculation of the solid-liquid interaction energy, and of the effect of the latter in reducing fracture surface energy. The reduction in fracture surface energy is estimated by comparison of the electronic contribution to the solid-liquid interaction energy with solid-solid bond energy for some 40 liquid-solid couples. Regular solution theory is used to estimate mutual solubility as the relative difference in parameter values. Embrittlement can be predicted by using reduction in fracture surface energy and solubility parameter difference as critical variables. The effect of solute additions to the liquid on the degree of embrittlement is interpreted via the same two variables; the principal effect of solutes is to modify solubility relationships at the solid-liquid interface.

  7. Glass-to-Metal Seal Against Liquid Helium

    NASA Technical Reports Server (NTRS)

    Watkins, John L.; Gatewood, John R.

    1987-01-01

    Simple compression joint with indium gasket forms demountable seal for superfluids. Seal developed for metal lid on glass jar used in experiments on liquid helium. Glass container allows contents to be viewed for such purposes as calibration of liquid-level detectors and adjustments of displacement plungers. Seal contains liquid helium even when temperature drops below 2.19K. Made from inexpensive, commercially available materials and parts.

  8. REMOVAL OF CERTAIN FISSION PRODUCT METALS FROM LIQUID BISMUTH COMPOSITIONS

    DOEpatents

    Dwyer, O.E.; Howe, H.E.; Avrutik, E.R.

    1959-11-24

    A method is described for purifying a solution of urarium in liquid bismuth containing at least one metal from the group consisting of selenium, tellurium, palladium, ruthenium, rhodium, niobium, and zirconium. The solution is contacted with zinc in an inert atmosphere to form a homogeneous melt, a solid zinc phase is formed, and the zinc phase containing the metal is separated from the melt.

  9. The emissivities of liquid metals at their fusion temperatures

    NASA Technical Reports Server (NTRS)

    Bonnell, D. W.; Treverton, J. A.; Valerga, A. J.; Margrave, J. L.

    1972-01-01

    A survey of the literature through 1969 shows an almost total lack of experimental emissivity data for metals in the liquid state. The emissivities for several transition metals and various other metals and compounds in the liquid state at their fusion temperatures have been determined. The technique used involves electromagnetic levitation-induction heating of the materials in an inert atmosphere. The brightness temperature of the liquid phase of the material is measured as the material is heated through fusion. Given a reliable value of the fusion temperature, which is available for most pure substances, one may readily calculate an emissivity for the liquid phase at the fusion temperatures. Even in cases where melting points are poorly known, the brightness temperatures are unique parameters, independent of the temperature scale and measured for a chemically defined system at a fixed point. Better emissivities may be recalculated as better melting point data become available.

  10. Dewetting Properties of Metallic Liquid Film on Nanopillared Graphene

    PubMed Central

    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

  11. Dewetting properties of metallic liquid film on nanopillared graphene.

    PubMed

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

    2014-02-03

    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.

  12. Emerging Applications of Liquid Metals Featuring Surface Oxides

    PubMed Central

    2014-01-01

    Gallium and several of its alloys are liquid metals at or near room temperature. Gallium has low toxicity, essentially no vapor pressure, and a low viscosity. Despite these desirable properties, applications calling for liquid metal often use toxic mercury because gallium forms a thin oxide layer on its surface. The oxide interferes with electrochemical measurements, alters the physicochemical properties of the surface, and changes the fluid dynamic behavior of the metal in a way that has, until recently, been considered a nuisance. Here, we show that this solid oxide “skin” enables many new applications for liquid metals including soft electrodes and sensors, functional microcomponents for microfluidic devices, self-healing circuits, shape-reconfigurable conductors, and stretchable antennas, wires, and interconnects. PMID:25283244

  13. Compatibility of materials with liquid metal targets for SNS

    SciTech Connect

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

    1996-06-01

    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, {Delta}T, 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 {approx}550{degrees}C, ferritic/martensitic steels have been satisfactory in Pb or Hg systems and the maximum temperature can be extended to {approx}650{degrees}C with additions of inhibitors to the liquid metal, e.g. Mg, Ti, Zr. Above {approx}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.

  14. On the use of liquid-metal electrodes for liquid impedance spectroscopy measurements

    NASA Astrophysics Data System (ADS)

    Kellis, Nathan; Mazzeo, Brian

    2010-10-01

    Electrode polarization is an obstacle to the accurate measurement of liquids containing ions. An atomically smooth surface electrode would potentially reduce uncertainties due to electrode polarization. Galinstan was used as a liquid-metal electrode for impedance spectroscopy measurements. Electrodes were formed by adhering Galinstan onto a PMMA plate. Two plates were placed in a parallel plate capacitor arrangement with a liquid reservoir. For comparison, an equivalent arrangement of stainless steel electrodes was constructed. Liquid was pipetted into the reservoirs, and impedance was measured from 40 Hz to 110 MHz. Galinstan electrodes showed increased electrode polarization for ionic liquids and chemical instability.

  15. Two-component Fermi-liquid theory - Equilibrium properties of liquid metallic hydrogen

    NASA Technical Reports Server (NTRS)

    Oliva, J.; Ashcroft, N. W.

    1981-01-01

    It is reported that the transition of condensed hydrogen from an insulating molecular crystal phase to a metallic liquid phase, at zero temperature and high pressure, appears possible. Liquid metallic hydrogen (LMH), comprising interpenetrating proton and electron fluids, would constitute a two-component Fermi liquid with both a very high component-mass ratio and long-range, species-dependent bare interactions. The low-temperature equilibrium properties of LMH are examined by means of a generalization to the case of two components of the phenomenological Landau Fermi-liquid theory, and the low-temperature specific heat, compressibility, thermal expansion coefficient and spin susceptibility are given. It is found that the specific heat and the thermal expansion coefficient are vastly greater in the liquid than in the corresponding solid, due to the presence of proton quasiparticle excitations in the liquid.

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

    SciTech Connect

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

    1993-09-01

    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.

  17. Liquid Galvanic Coatings for Protection of Imbedded Metals

    NASA Technical Reports Server (NTRS)

    MacDowell, Louis G. (Inventor); Curran, Joseph J. (Inventor)

    2003-01-01

    Coating compositions and methods of their use are described herein for the reduction of corrosion in imbedded metal structures. The coatings are applied as liquids to an external surface of a substrate in which the metal structures are imbedded. The coatings are subsequently allowed to dry. The liquid applied coatings provide galvanic protection to the imbedded metal structures. Continued protection can be maintained with periodic reapplication of the coating compositions, as necessary, to maintain electrical continuity. Because the coatings may be applied using methods similar to standard paints, and because the coatings are applied to external surfaces of the substrates in which the metal structures are imbedded, the corresponding corrosion protection may be easily maintained. The coating compositions are particularly useful in the protection of metal-reinforced concrete.

  18. The Parameterization of Solid Metal-Liquid Metal Partitioning of Siderophile Elements

    NASA Technical Reports Server (NTRS)

    Chabot, N. L.; Jones, J. H.

    2003-01-01

    The composition of a metallic liquid can significantly affect the partitioning behavior of elements. For example, some experimental solid metal-liquid metal partition coefficients have been shown to increase by three orders of magnitude with increasing S-content of the metallic liquid. Along with S, the presence of other light elements, such as P and C, has also been demonstrated to affect trace element partitioning behavior. Understanding the effects of metallic composition on partitioning behavior is important for modeling the crystallization of magmatic iron meteorites and the chemical effects of planetary differentiation. It is thus useful to have a mathematical expression that parameterizes the partition coefficient as a function of the composition of the metal. Here we present a revised parameterization method, which builds on the theory of the current parameterization of Jones and Malvin and which better handles partitioning in multi-light-element systems.

  19. Separation of metals by supported liquid membranes

    SciTech Connect

    Takigawa, D.Y.

    1990-12-31

    A supported liquid membrane system for the separation of a preselected chemical species within a feedstream, preferably an aqueous feedstream, includes a feed compartment containing a feed solution having at least one preselected chemical species therein, a stripping compartment containing a stripping solution therein, and a microporous polybenzimidazole membrane situated between the compartments, the microporous polybenzimidazole membrane containing an extractant mixture selective for the preselected chemical species within the membrane pores is disclosed along with a method of separating preselected chemical species from a feedstream with such a system, and a supported liquid membrane for use in such a system.

  20. Free surface stability of liquid metal plasma facing components

    NASA Astrophysics Data System (ADS)

    Fiflis, P.; Christenson, M.; Szott, M.; Kalathiparambil, K.; Ruzic, D. N.

    2016-10-01

    An outstanding concern raised over the implementation of liquid metal plasma facing components in fusion reactors is the potential for ejection of liquid metal into the fusion plasma. The influences of Rayleigh-Taylor-like and Kelvin-Helmholtz-like instabilities were experimentally observed and quantified on the thermoelectric-driven liquid-metal plasma-facing structures (TELS) chamber at the University of Illinois at Urbana-Champaign. To probe the stability boundary, plasma currents and velocities were first characterized with a flush probe array. Subsequent observations of lithium ejection under exposure in the TELS chamber exhibited a departure from previous theory based on linear perturbation analysis. The stability boundary is mapped experimentally over the range of plasma impulses of which TELS is capable to deliver, and a new theory based on a modified set of the shallow water equations is presented which accurately predicts the stability of the lithium surface under plasma exposure.

  1. Review of liquid metal heat pipe work at Los Alamos

    NASA Astrophysics Data System (ADS)

    Reid, Robert S.; Merrigan, Michael A.; Sena, J. Tom

    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.

  2. Review of liquid metal heat pipe work at Los Alamos

    SciTech Connect

    Reid, R.S.; Merrigan, M.A.; Sena, J.T. )

    1991-01-10

    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.

  3. Review of liquid metal heat pipe work at Los Alamos

    NASA Astrophysics Data System (ADS)

    Reid, Robert S.; Merrigan, Michael A.; Sena, J. Tom

    1991-01-01

    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.

  4. Review of liquid metal heat pipe work at Los Alamos

    NASA Astrophysics Data System (ADS)

    Reid, Robert S.; Merrigan, Michael A.; Sena, J. T.

    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 reference section citing sources where these works may be found.

  5. Temperature-dependent liquid metal flowrate control device

    DOEpatents

    Carlson, Roger 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.

  6. Stretchable Metamaterial Absorber Using Liquid Metal-Filled Polydimethylsiloxane (PDMS)

    PubMed Central

    Kim, Kyeongseob; Lee, Dongju; Eom, Seunghyun; Lim, Sungjoon

    2016-01-01

    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. PMID:27077861

  7. Review of liquid metal heat pipe work at Los Alamos

    SciTech Connect

    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.

  8. Distinct metallization and atomization transitions in dense liquid hydrogen.

    PubMed

    Mazzola, Guglielmo; Sorella, Sandro

    2015-03-13

    We perform molecular dynamics simulations driven by accurate quantum Monte Carlo forces on dense liquid hydrogen. There is a recent report of a complete atomization transition between a mixed molecular-atomic liquid and a completely dissociated fluid in an almost unaccessible pressure range [Nat. Commun. 5, 3487 (2014)]. Here, instead, we identify a different transition between the fully molecular liquid and the mixed-atomic fluid at ∼400  GPa, i.e., in a much more interesting pressure range. We provide numerical evidence supporting the metallic behavior of this intermediate phase. Therefore, we predict that the metallization at finite temperature occurs in this partially dissociated molecular fluid, well before the complete atomization of the liquid. At high temperature this first-order transition becomes a crossover, in very good agreement with the experimental observation. Several systematic tests supporting the quality of our large scale calculations are also reported.

  9. A liquid-liquid transition can exist in monatomic transition metals with a positive melting slope

    PubMed Central

    Lee, Byeongchan; Lee, Geun Woo

    2016-01-01

    Liquid-liquid transitions under high pressure are found in many elemental materials, but the transitions are known to be associated with either sp-valent materials or f-valent rare-earth elements, in which the maximum or a negative slope in the melting line is readily suggestive of the transition. Here we find a liquid-liquid transition with a positive melting slope in transition metal Ti from structural, electronic, and thermodynamic studies using ab-initio molecular dynamics calculations, showing diffusion anomaly, but no density anomaly. The origin of the transition in liquid Ti is a pressure-induced increase of local structures containing very short bonds with directionality in electronic configurations. This behavior appears to be characteristic of the early transition metals. In contrast, the late transition metal liquid Ni does not show the L-L transition with pressure. This result suggests that the possibility of the L-L transition decreases from early to late transition metals as electronic structures of late transition metals barely have a Jahn-Teller effect and bond directionality. Our results generalize that a phase transition in disordered materials is found with any valence band regardless of the sign of the melting slope, but related to the symmetry of electronic structures of constituent elements. PMID:27762334

  10. Coalescence of Immiscible Liquid Metal Drop on Graphene

    PubMed Central

    Li, Tao; Li, Jie; Wang, Long; Duan, Yunrui; Li, Hui

    2016-01-01

    Molecular dynamics simulations were performed to investigate the wetting and coalescence of liquid Al and Pb drops on four carbon-based substrates. We highlight the importance of the microstructure and surface topography of substrates in the coalescence process. Our results show that the effect of substrate on coalescence is achieved by changing the wettability of the Pb metal. Additionally, we determine the critical distance between nonadjacent Al and Pb films required for coalescence. These findings improve our understanding of the coalescence of immiscible liquid metals at the atomistic level. PMID:27667589

  11. Contactless electromagnetic phase-shift flowmeter for liquid metals

    NASA Astrophysics Data System (ADS)

    Priede, Jānis; Buchenau, Dominique; Gerbeth, Gunter

    2011-05-01

    We present a concept and test results of an eddy-current flowmeter for liquid metals. The flow rate is determined by applying a weak ac magnetic field to a liquid metal flow and measuring the flow-induced phase disturbance in the external electromagnetic field. The phase disturbance is found to be more robust than that of the amplitude used in conventional eddy-current flowmeters. The basic characteristics of this type of flowmeter are analysed using simple theoretical models, where the flow is approximated by a solid body motion. Design of such a flowmeter is presented and its test results are reported.

  12. Dense simple plasmas as high-temperature liquid simple metals

    NASA Technical Reports Server (NTRS)

    Perrot, F.

    1990-01-01

    The thermodynamic properties of dense plasmas considered as high-temperature liquid metals are studied. An attempt is made to show that the neutral pseudoatom picture of liquid simple metals may be extended for describing plasmas in ranges of densities and temperatures where their electronic structure remains 'simple'. The primary features of the model when applied to plasmas include the temperature-dependent self-consistent calculation of the electron charge density and the determination of a density and temperature-dependent ionization state.

  13. Electromagnetically Sustained Liquid Metal Flow for Feedback Stabilization Studies

    NASA Astrophysics Data System (ADS)

    Mirhoseini, Seyyed Mohammad; Volpe, Francesco

    2015-11-01

    Liquid metal walls in fusion reactors, whether nearly static or rapidly flowing, will be subject to instabilities that will make them locally bulge, thus entering in contact with the plasma, or deplete, hence exposing the underlying solid substrate. To prevent this, research has begun at Columbia University to create liquid metal flows and demonstrate their stabilization by electromagnetic forces, adjusted in feedback with thickness measurements. Here we present initial results regarding the sustainment of a flow of Galinstan (a gallium, indium, tin alloy) by a special pump consisting of a ferromagnetic rotor, with permanent magnets mounted on it. The magnetic field is partly ``frozen'' in the liquid metal surrounding the rotor. Therefore, as the field rotates, the liquid metal rotates as well, although with a slip factor. This solution was preferred to conventional pumps, which would enter in electrical contact with the metal flow. The pump, 3D-printed at Columbia, allows to adjust the flow-velocity from few mm/s to several cm/s.

  14. Factors Affecting Liquid-Metal Embrittlement in C-103

    NASA Technical Reports Server (NTRS)

    Mclemore, R.; Lampson, F. K.

    1982-01-01

    Results of a study of weld cracks on Space Shuttle control thrustors point toward better understanding of cracking problem in columbium metal, which has also plagued nonaerospace users. Although liquid-metal embrittlement is known to be cause of problem, factors affecting growth and severity of cracks are not well understood. New results tie crack growth to type of contaminants present, grain size and level of stress present while welding is done.

  15. Characteristics of the boat inductor for keeping liquid metal in the suspended state

    NASA Technical Reports Server (NTRS)

    Fogel, A. A.; Siforova, T. A.; Mezdrogina, M. M.

    1985-01-01

    Characteristics of the boat inductor for keeping liquid metal in the suspended state are examined. Behavioral features of the liquid metal, and the suspension boundary of liquid metal in the lower position are discussed. It is concluded that the inductor can be used to crystallize metals in the suspended state.

  16. A sliding cell technique for diffusion measurements in liquid metals

    SciTech Connect

    Geng, Yongliang; Zhu, Chunao; Zhang, Bo

    2014-03-15

    The long capillary and shear cell techniques are the usual methods for diffusion measurements in liquid metals. Here we present a new “sliding cell technique” to measure interdiffusion in liquid alloys, which combines the merits of these two methods. Instead of a number of shear cells, as used in the shear cell method, only one sliding cell is designed to separate and join the liquid diffusion samples. Using the sliding cell technique, the influence of the heating process (which affects liquid diffusion measurements in the conventional long capillary method) can be eliminated. Time-dependent diffusion measurements at the same isothermal temperature were carried out in Al-Cu liquids. Compared with the previous results measured by in-situ X-ray radiography, the obtained liquid diffusion coefficient in this work is believed to be influenced by convective flow. The present work further supports the idea that to obtain accurate diffusion constants in liquid metals, the measurement conditions must be well controlled, and there should be no temperature gradients or other disturbances.

  17. Plasma torch with liquid metal electrodes

    SciTech Connect

    Predtechenskii, M.R.; Tukhto, O.M.

    2006-03-15

    In order to eliminate the negative effect of erosion processes on electrodes in arc plasma generators, a new scheme of arc discharge was proposed in which the surface of a molten metal acts as electrodes. A plasma reactor was designed on the basis of this concept. The electrophysical characteristics of such a discharge in steam and air as plasma gases were studied. Experiments on destruction of toxic polychlorinated biphenyls and steam coal gasification were performed.

  18. LSPR properties of metal nanoparticles adsorbed at a liquid-liquid interface.

    PubMed

    Yang, Zhilin; Chen, Shu; Fang, Pingping; Ren, Bin; Girault, Hubert H; Tian, Zhongqun

    2013-04-21

    Unlike the solid-air and solid-liquid interfaces, the optical properties of metal nanoparticles adsorbed at the liquid-liquid interface have not been theoretically exploited to date. In this work, the three dimensional finite difference time domain (3D-FDTD) method is employed to clarify the localized surface plasmon resonance (LSPR) based optical properties of gold nanoparticles (NPs) adsorbed at the water-oil interface, including near field distribution, far field absorption and their relevance. The LSPR spectra of NPs located at a liquid-liquid interface are shown to differ significantly from those in a uniform liquid environment or at the other interfaces. The absorption spectra exhibit two distinct LSPR peaks, the positions and relative strengths of which are sensitive to the dielectric properties of each liquid and the exact positions of the NPs with respect to the interface. Precise control of the particles' position and selection of the appropriate wavelength of the excitation laser facilitates the rational design and selective excitation of localized plasmon modes for interfacial NPs, a necessary advance for the exploration of liquid-liquid interfaces via surface enhanced Raman spectroscopy (SERS). According to our calculations, the SERS enhancement factor for Au nanosphere dimers at the water-oil interface can be as high as 10(7)-10(9), implying significant promise for future investigations of interfacial structure and applications of liquid-liquid interfaces towards chemical analysis.

  19. Ecotoxicology of heavy metals: Liquid-phase extraction by nanosorbents

    NASA Astrophysics Data System (ADS)

    Burakov, A.; Romantsova, I.; Babkin, A.; Neskoromnaya, E.; Kucherova, A.; Kashevich, Z.

    2015-11-01

    The paper considers the problem of extreme toxicity heavy metal compounds dissolved in wastewater and liquid emissions of industrial enterprises to living organisms and environment as a whole. The possibility of increasing extraction efficiency of heavy metal ions by sorption materials was demonstrated. The porous space of the latter was modified by carbon nanotubes (CNTs) during process of the chemical vapour deposition (CVD) of carbon on metal oxide catalysts. The increasing of the sorption capacity (10-30%) and the sorption rate of nanomodified activated carbons in comparison with standard materials in the example of absorption of Co2+ and Ni2+ ions from aqueous solutions was proven.

  20. An Integrated Liquid Cooling System Based on Galinstan Liquid Metal Droplets.

    PubMed

    Zhu, Jiu Yang; Tang, Shi-Yang; Khoshmanesh, Khashayar; Ghorbani, Kamran

    2016-01-27

    The continued miniaturization of electronic components demands integrated liquid cooling systems with minimized external connections and fabrication costs that can be implanted very close to localized hot spots. This might be challenging for existing liquid cooling systems because most of them rely on external pumps, connecting tubes, and microfabricated heat sinks. Here, we demonstrate an integrated liquid cooling system by utilizing a small droplet of liquid metal Galinstan, which is placed over the hot spot. Energizing the liquid metal droplet with a square wave signal creates a surface tension gradient across the droplet, which induces Marangoni flow over the surface of droplet. This produces a high flow rate of coolant medium through the cooling channel, enabling a "soft" pump. At the same time, the high thermal conductivity of liquid metal extends the heat transfer surface and facilitates the dissipation of heat, enabling a "soft" heat sink. This facilitates the rapid cooling of localized hot spots, as demonstrated in our experiments. Our technology facilitates customized liquid cooling systems with simple fabrication and assembling processes, with no moving parts that can achieve high flow rates with low power consumption. PMID:26716607

  1. An Integrated Liquid Cooling System Based on Galinstan Liquid Metal Droplets.

    PubMed

    Zhu, Jiu Yang; Tang, Shi-Yang; Khoshmanesh, Khashayar; Ghorbani, Kamran

    2016-01-27

    The continued miniaturization of electronic components demands integrated liquid cooling systems with minimized external connections and fabrication costs that can be implanted very close to localized hot spots. This might be challenging for existing liquid cooling systems because most of them rely on external pumps, connecting tubes, and microfabricated heat sinks. Here, we demonstrate an integrated liquid cooling system by utilizing a small droplet of liquid metal Galinstan, which is placed over the hot spot. Energizing the liquid metal droplet with a square wave signal creates a surface tension gradient across the droplet, which induces Marangoni flow over the surface of droplet. This produces a high flow rate of coolant medium through the cooling channel, enabling a "soft" pump. At the same time, the high thermal conductivity of liquid metal extends the heat transfer surface and facilitates the dissipation of heat, enabling a "soft" heat sink. This facilitates the rapid cooling of localized hot spots, as demonstrated in our experiments. Our technology facilitates customized liquid cooling systems with simple fabrication and assembling processes, with no moving parts that can achieve high flow rates with low power consumption.

  2. Wideband-Switchable Metamaterial Absorber Using Injected Liquid Metal.

    PubMed

    Kim, Hyung Ki; Lee, Dongju; Lim, Sungjoon

    2016-01-01

    Metamaterial absorbers can provide good solutions for radar-cross-section (RCS) reduction. In spite of their attractive features of thinness, lightness, and low cost, resonant metamaterial absorbers have a drawback of narrow bandwidth. For practical radar applications, wideband absorbers are necessary. In this paper, we propose a wideband-switchable metamaterial absorber using liquid metal. In order to reduce RCS both for X-band and C-band, the switchable Jerusalem cross (JC) resonator is introduced. The JC resonator consists of slotted circular rings, chip resistors, and microfluidic channels. The JC resonator is etched on a flexible printed circuit board (FPCB), and the microfluidic channels are laser-etched on a polydimethylsiloxane (PDMS) material. The proposed absorber can switch the absorption frequency band by injecting a liquid metal alloy into the channels. The performance of the absorber was demonstrated through full-wave simulation and through measurements employing prototypes. The experimental results showed absorption ratios of over 90% from 7.43 GHz to 14.34 GHz, and from 5.62 GHz to 7.3 GHz, with empty channels and liquid metal-filled channels, respectively. Therefore, the absorption band was successfully switched between the C-band (4-8 GHz) and the X-band (8-12 GHz) by injecting liquid metal eutectic gallium indium alloy (EGaIn) into the channels. PMID:27546310

  3. Solubility data are compiled for metals in liquid zinc

    NASA Technical Reports Server (NTRS)

    Dillon, I. G.; Johnson, I.

    1967-01-01

    Available data is compiled on the solubilities of various metals in liquid zinc. The temperature dependence of the solubility data is expressed using the empirical straight line relationship existing between the logarithm of the solubility and the reciprocal of the absolute temperature.

  4. Control of impurity concentration in liquid metals by neutron scattering

    SciTech Connect

    Morozov, V. A.; Novikov, A. G.; Savostin, V. V.

    2011-12-15

    A technique is proposed for determining the impurity concentration in liquid metal-impurity systems. This technique does not require special measurements or geometry: information about the impurity concentration can be obtained directly from the data collected during the diffraction experiment. The impurity concentrations in a lead melt with a potassium impurity and in a sodium melt with a lead impurity are determined.

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

    PubMed

    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 < 1. Most analog models of planetary dynamos, however, use moderate Pr fluids, and the systematic influence of reducing Pr is not well understood. We perform 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 and Pr > 1 fluids, respectively.

  6. Handwritten, Soft Circuit Boards and Antennas Using Liquid Metal Nanoparticles.

    PubMed

    Lin, Yiliang; Cooper, Christopher; Wang, Meng; Adams, Jacob J; Genzer, Jan; Dickey, Michael D

    2015-12-22

    Soft conductors are created by embedding liquid metal nanoparticles between two elastomeric sheets. Initially, the particles form an electrically insulating composite. Soft circuit boards can be handwritten by a stylus, which sinters the particles into conductive traces by applying localized mechanical pressure to the elastomeric sheets. Antennas with tunable frequencies are formed by sintering nanoparticles in microchannels.

  7. Wideband-Switchable Metamaterial Absorber Using Injected Liquid Metal

    NASA Astrophysics Data System (ADS)

    Kim, Hyung Ki; Lee, Dongju; Lim, Sungjoon

    2016-08-01

    Metamaterial absorbers can provide good solutions for radar-cross-section (RCS) reduction. In spite of their attractive features of thinness, lightness, and low cost, resonant metamaterial absorbers have a drawback of narrow bandwidth. For practical radar applications, wideband absorbers are necessary. In this paper, we propose a wideband-switchable metamaterial absorber using liquid metal. In order to reduce RCS both for X-band and C-band, the switchable Jerusalem cross (JC) resonator is introduced. The JC resonator consists of slotted circular rings, chip resistors, and microfluidic channels. The JC resonator is etched on a flexible printed circuit board (FPCB), and the microfluidic channels are laser-etched on a polydimethylsiloxane (PDMS) material. The proposed absorber can switch the absorption frequency band by injecting a liquid metal alloy into the channels. The performance of the absorber was demonstrated through full-wave simulation and through measurements employing prototypes. The experimental results showed absorption ratios of over 90% from 7.43 GHz to 14.34 GHz, and from 5.62 GHz to 7.3 GHz, with empty channels and liquid metal-filled channels, respectively. Therefore, the absorption band was successfully switched between the C-band (4-8 GHz) and the X-band (8-12 GHz) by injecting liquid metal eutectic gallium indium alloy (EGaIn) into the channels.

  8. Wideband-Switchable Metamaterial Absorber Using Injected Liquid Metal

    PubMed Central

    Kim, Hyung Ki; Lee, Dongju; Lim, Sungjoon

    2016-01-01

    Metamaterial absorbers can provide good solutions for radar-cross-section (RCS) reduction. In spite of their attractive features of thinness, lightness, and low cost, resonant metamaterial absorbers have a drawback of narrow bandwidth. For practical radar applications, wideband absorbers are necessary. In this paper, we propose a wideband-switchable metamaterial absorber using liquid metal. In order to reduce RCS both for X-band and C-band, the switchable Jerusalem cross (JC) resonator is introduced. The JC resonator consists of slotted circular rings, chip resistors, and microfluidic channels. The JC resonator is etched on a flexible printed circuit board (FPCB), and the microfluidic channels are laser-etched on a polydimethylsiloxane (PDMS) material. The proposed absorber can switch the absorption frequency band by injecting a liquid metal alloy into the channels. The performance of the absorber was demonstrated through full-wave simulation and through measurements employing prototypes. The experimental results showed absorption ratios of over 90% from 7.43 GHz to 14.34 GHz, and from 5.62 GHz to 7.3 GHz, with empty channels and liquid metal-filled channels, respectively. Therefore, the absorption band was successfully switched between the C-band (4–8 GHz) and the X-band (8–12 GHz) by injecting liquid metal eutectic gallium indium alloy (EGaIn) into the channels. PMID:27546310

  9. Liquid metal cooled nuclear reactors with passive cooling system

    DOEpatents

    Hunsbedt, Anstein; Fanning, Alan W.

    1991-01-01

    A liquid metal cooled nuclear reactor having a passive cooling system for removing residual heat resulting from fuel decay during reactor shutdown. The passive cooling system comprises a plurality of cooling medium flow circuits which cooperate to remove and carry heat away from the fuel core upon loss of the normal cooling flow circuit to areas external thereto.

  10. Wideband-Switchable Metamaterial Absorber Using Injected Liquid Metal.

    PubMed

    Kim, Hyung Ki; Lee, Dongju; Lim, Sungjoon

    2016-08-22

    Metamaterial absorbers can provide good solutions for radar-cross-section (RCS) reduction. In spite of their attractive features of thinness, lightness, and low cost, resonant metamaterial absorbers have a drawback of narrow bandwidth. For practical radar applications, wideband absorbers are necessary. In this paper, we propose a wideband-switchable metamaterial absorber using liquid metal. In order to reduce RCS both for X-band and C-band, the switchable Jerusalem cross (JC) resonator is introduced. The JC resonator consists of slotted circular rings, chip resistors, and microfluidic channels. The JC resonator is etched on a flexible printed circuit board (FPCB), and the microfluidic channels are laser-etched on a polydimethylsiloxane (PDMS) material. The proposed absorber can switch the absorption frequency band by injecting a liquid metal alloy into the channels. The performance of the absorber was demonstrated through full-wave simulation and through measurements employing prototypes. The experimental results showed absorption ratios of over 90% from 7.43 GHz to 14.34 GHz, and from 5.62 GHz to 7.3 GHz, with empty channels and liquid metal-filled channels, respectively. Therefore, the absorption band was successfully switched between the C-band (4-8 GHz) and the X-band (8-12 GHz) by injecting liquid metal eutectic gallium indium alloy (EGaIn) into the channels.

  11. Generation and characterization of gas bubbles in liquid metals

    SciTech Connect

    Eckert, S.; Gerbeth, G.; Witke, W.

    1996-06-01

    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. Turbulent convection in liquid metal with and without rotation

    PubMed Central

    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 buoyancy forcing and rotation periods (E). Our primary diagnostic is the efficiency of convective heat transfer . In general, we find that the convective behavior of liquid metal differs substantially from that of moderate 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 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 and fluids, respectively. PMID:23569262

  13. Wideband-Switchable Metamaterial Absorber Using Injected Liquid Metal

    NASA Astrophysics Data System (ADS)

    Kim, Hyung Ki; Lee, Dongju; Lim, Sungjoon

    2016-08-01

    Metamaterial absorbers can provide good solutions for radar-cross-section (RCS) reduction. In spite of their attractive features of thinness, lightness, and low cost, resonant metamaterial absorbers have a drawback of narrow bandwidth. For practical radar applications, wideband absorbers are necessary. In this paper, we propose a wideband-switchable metamaterial absorber using liquid metal. In order to reduce RCS both for X-band and C-band, the switchable Jerusalem cross (JC) resonator is introduced. The JC resonator consists of slotted circular rings, chip resistors, and microfluidic channels. The JC resonator is etched on a flexible printed circuit board (FPCB), and the microfluidic channels are laser-etched on a polydimethylsiloxane (PDMS) material. The proposed absorber can switch the absorption frequency band by injecting a liquid metal alloy into the channels. The performance of the absorber was demonstrated through full-wave simulation and through measurements employing prototypes. The experimental results showed absorption ratios of over 90% from 7.43 GHz to 14.34 GHz, and from 5.62 GHz to 7.3 GHz, with empty channels and liquid metal-filled channels, respectively. Therefore, the absorption band was successfully switched between the C-band (4–8 GHz) and the X-band (8–12 GHz) by injecting liquid metal eutectic gallium indium alloy (EGaIn) into the channels.

  14. Topology-generating interfacial pattern formation during liquid metal dealloying

    PubMed Central

    Geslin, Pierre-Antoine; McCue, Ian; Gaskey, Bernard; Erlebacher, Jonah; Karma, Alain

    2015-01-01

    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. PMID:26582248

  15. Surface entropy of liquid transition and noble metals

    NASA Astrophysics Data System (ADS)

    Gosh, R. C.; Das, Ramprosad; Sen, Sumon C.; Bhuiyan, G. M.

    2015-07-01

    Surface entropy of liquid transition and noble metals has been investigated using an expression obtained from the hard-sphere (HS) theory of liquid. The expression is developed from the Mayer's extended surface tension formula [Journal of Non-Crystalline Solids 380 (2013) 42-47]. For interionic interaction in metals, Brettonet-Silbert (BS) pseudopotentials and embedded atom method (EAM) potentials have been used. The liquid structure is described by the variational modified hypernetted chain (VMHNC) theory. The essential ingredient of the expression is the temperature dependent effective HS diameter (or packing fraction), which is calculated from the aforementioned potentials together with the VMHNC theory. The obtained results for the surface entropy using the effective HS diameter are found to be good in agreement with the available experimental as well as other theoretical values.

  16. Topology-generating interfacial pattern formation during liquid metal dealloying

    DOE PAGES

    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 growthmore » 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. Furthermore, we deduce scaling laws governing microstructural length scales and dealloying kinetics.« less

  17. Computer modeling of convection in the liquid metal during solidification

    NASA Technical Reports Server (NTRS)

    Lott, R. L., Jr.; Cheng, T. S.

    1988-01-01

    Numerical methods are used to study thermally/gravitationally induced convection during solidification. The primary object is aimed at understanding the flow field in the liquid metal pool due to convection. An Al-0.5Fe weight percent alloy is assumed to fill a small scale vertical rectangular enclosure model for this study. The Alternating Direction Implicit method and Successive Overrelaxation method are employed to solve these equations, which include the energy balance equation coupled with the mass and momentum equations. Both transient and steady state conditions under 1 g and low gravity (0.001 g) are investigated. The solutions for the two-dimensional isotherms and streamlines under 1 g conditions are graphically presented. The quantitative results show that the convection which occurs in the liquid metal pool is very small and is likely to have a negligible effect on the solute redistribution ahead of the solid-liquid interface.

  18. The emissivities of liquid metals at their fusion temperatures.

    NASA Technical Reports Server (NTRS)

    Bonnell, D. W.; Treverton, J. A.; Valerga, A. J.; Margrave , J. L.

    1972-01-01

    The emissivities for several transition metals and various other metals and compounds in the liquid state at their fusion temperatures have been determined in this laboratory. The technique used involves electromagnetic levitation-induction heating of the materials in an inert atmosphere. The brightness temperature of the liquid phase of the material is measured as the material is heated through fusion. Given a reliable value of the fusion temperature, which is available for most pure substances, one may readily calculate an emissivity for the liquid phase at the fusion temperature. Even in cases where melting points are poorly known, the brightness temperatures are unique parameters, independent of the temperature scale and measured for a chemically defined system at a fixed point.

  19. Topology-generating interfacial pattern formation during liquid metal dealloying

    SciTech Connect

    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. Furthermore, we deduce scaling laws governing microstructural length scales and dealloying kinetics.

  20. Liquid Metal Propellant Feed System for Plasma Propulsion

    NASA Technical Reports Server (NTRS)

    Markusic, T. E.

    2004-01-01

    High-power plasma thrusters that utilize molten metallic propellants (e.g., the Lithium Lorentz Force Accelerator) are currently being investigated as a primary propulsion option for in-space nuclear-electric systems. A critical component of the thruster is the propellant feed system, which must reliably and accurately pump liquid metal into the thruster discharge chamber. We present design details and calibration results for a compact liquid metal propellant feed system that contains no moving parts, for use in laboratory testing of plasma thrusters. Feed line pressure is maintained using an MHD flow coupler, and the flow rate is monitored using a simple voltage divider, which is submerged in the propellant reservoir. Results for lithium and gallium propellants show capability to meter propellant at flow rates up to 10 +/- 0.1 mg/s.

  1. Liquid Metal Infiltration Processing of Metallic Composites: A Critical Review

    NASA Astrophysics Data System (ADS)

    Sree Manu, K. M.; Ajay Raag, L.; Rajan, T. P. D.; Gupta, Manoj; Pai, B. C.

    2016-07-01

    Metal matrix composites (MMC) are one of the advanced materials widely used for aerospace, automotive, defense, and general engineering applications. MMC can be tailored to have superior properties such as enhanced high-temperature performance, high specific strength and stiffness, increased wear resistance, better thermal and mechanical fatigue, and creep resistance than those of unreinforced alloys. To fabricate such composites with ideal properties, the processing technique has to ensure high volume fraction of reinforcement incorporation, uniform distribution of the reinforcement, and acceptable adhesion between the matrix and the reinforcing phase without unwanted interfacial reactions which degrades the mechanical properties. A number of processing techniques such as stir casting/vortex method, powder metallurgy, infiltration, casting etc. have been developed to synthesize MMC employing a variety of alloy and the reinforcement's combinations. Among these, infiltration process is widely used for making MMC with high volume fraction of reinforcements and offers many more advantages compared to other conventional manufacturing processes. The present paper critically reviews the various infiltration techniques used for making the MMC, their process parameters, characteristics, and selected studies carried out worldwide and by authors on the development of metal ceramic composites by squeeze infiltration process.

  2. Liquid Metal Infiltration Processing of Metallic Composites: A Critical Review

    NASA Astrophysics Data System (ADS)

    Sree Manu, K. M.; Ajay Raag, L.; Rajan, T. P. D.; Gupta, Manoj; Pai, B. C.

    2016-10-01

    Metal matrix composites (MMC) are one of the advanced materials widely used for aerospace, automotive, defense, and general engineering applications. MMC can be tailored to have superior properties such as enhanced high-temperature performance, high specific strength and stiffness, increased wear resistance, better thermal and mechanical fatigue, and creep resistance than those of unreinforced alloys. To fabricate such composites with ideal properties, the processing technique has to ensure high volume fraction of reinforcement incorporation, uniform distribution of the reinforcement, and acceptable adhesion between the matrix and the reinforcing phase without unwanted interfacial reactions which degrades the mechanical properties. A number of processing techniques such as stir casting/vortex method, powder metallurgy, infiltration, casting etc. have been developed to synthesize MMC employing a variety of alloy and the reinforcement's combinations. Among these, infiltration process is widely used for making MMC with high volume fraction of reinforcements and offers many more advantages compared to other conventional manufacturing processes. The present paper critically reviews the various infiltration techniques used for making the MMC, their process parameters, characteristics, and selected studies carried out worldwide and by authors on the development of metal ceramic composites by squeeze infiltration process.

  3. Corrosion behavior of surface treated steel in liquid sodium negative electrode of liquid metal battery

    NASA Astrophysics Data System (ADS)

    Lee, Jeonghyeon; Shin, Sang Hun; Lee, Jung Ki; Choi, Sungyeol; Kim, Ji Hyun

    2016-03-01

    While liquid metal batteries are attractive options for grid-scale energy storage applications as they have flexible siting capacities and small footprints, the compatibility between structural materials such as current collectors and negative electrode such as sodium is one of major issues for liquid metal batteries. Non-metallic elements such as carbon, oxygen, and nitrogen in the liquid sodium influence the material behaviors of the cell construction materials in the battery system. In this study, the compatibility of structural materials with sodium is investigated in high temperature liquid sodium, and electrochemical impedance spectroscopy (EIS) is used to monitor in-situ the corrosion behavior at the surface of materials in sodium. Chemical vapor deposition (CVD) coatings of SiC and Si3N4 are applied as protective barriers against dissolution and corrosion on the steel surface. The results show that CVD coating of Si compounds can delay corrosion of steel in high temperature liquid sodium comparing to the result of as-received specimens, while SiC coating is more durable than Si3N4 coating in high temperature liquid sodium.

  4. Friction and wear of selected metals and of carbons in liquid natural gas

    NASA Technical Reports Server (NTRS)

    Wisander, D. W.

    1971-01-01

    Friction and wear experiments were conducted with hemispherically tipped (4.76-mm radius) rider specimens in sliding contact with a rotating disk submerged in liquid natural gas (LNG). The program included metal combinations and carbon-metal combinations. These experiments revealed that the metal combinations were not lubricated by the LNG. Carbons had much lower wear in LNG than in liquid hydrogen or in liquid nitrogen. (Wear of carbon in liquid hydrogen was 100 times that in LNG.) The friction coefficients obtained in LNG (0.6 for metal-metal and 0.2 for carbon-metal) are similar to those obtained in liquid hydrogen.

  5. Separation of metal species by supported liquid membranes

    SciTech Connect

    Danesi, P.R.

    1985-01-01

    The work performed in the Separation Chemistry Group of the Chemistry Division of Argonne National Laboratory on the transport and separation properties of supported liquid membranes (SLM) are reviewed. The models and equations which describe the permeation through SLMs of metal species are described. These models have been tested with various carriers absorbed on flat-sheet and hollow-fiber SLMs by measuring the permeation of several metal species of hydrometallurgical and nuclear interest. An equation for the separation factor of metal species in SLM processes and examples of separations of metal ions are reported. The possibility of bypassing the single stage character of SLM separations by using multilayer composite SLMs, arranged in series, is also analyzed. Finally, the factors which control the stability of SLMs are briefly discussed. 28 references, 27 figures, 6 tables.

  6. Separation of metal species by supported liquid membranes

    SciTech Connect

    Danesi, P.R.

    1984-01-01

    The works performed on the transport and separation properties of supported liquid membranes (SLM) are reviewed. The models and equations which describe the permeation through SLMs of metal species are described. These models have been tested with various carriers absorbed on flat-sheet and hollow-fiber SLMs by measuring the permeation of several metal species of hydrometallurgical and nuclear interest. An equation for the separation factor of metal species in SLM processes and examples of separations of metal ions are reported. The possibility of bypassing the single stage character of SLM separations by using multilayer composite SLMs, arranged in series, is also analyzed. Finally, the factors which control the stability of SLMs are briefly discussed.

  7. Surface tension of liquid metals and alloys--recent developments.

    PubMed

    Egry, I; Ricci, E; Novakovic, R; Ozawa, S

    2010-09-15

    Surface tension measurements are a central task in the study of surfaces and interfaces. For liquid metals, they are complicated by the high temperatures and the consequently high reactivity characterising these melts. In particular, oxidation of the liquid surface in combination with evaporation phenomena requires a stringent control of the experimental conditions, and an appropriate theoretical treatment. Recently, much progress has been made on both sides. In addition to improving the conventional sessile drop technique, new containerless methods have been developed for surface tension measurements. This paper reviews the experimental progress made in the last few years, and the theoretical framework required for modelling and understanding the relevant physico-chemical surface phenomena.

  8. Liquid-solid joining of bulk metallic glasses.

    PubMed

    Huang, Yongjiang; Xue, Peng; Guo, Shu; Wu, Yang; Cheng, Xiang; Fan, Hongbo; Ning, Zhiliang; Cao, Fuyang; Xing, Dawei; Sun, Jianfei; Liaw, Peter K

    2016-01-01

    Here, we successfully welded two bulk metallic glass (BMG) materials, Zr51Ti5Ni10Cu25Al9 and Zr50.7Cu28Ni9Al12.3 (at. %), using a liquid-solid joining process. An atomic-scale metallurgical bonding between two BMGs can be achieved. The interface has a transition layer of ~50 μm thick. The liquid-solid joining of BMGs can shed more insights on overcoming their size limitation resulting from their limited glass-forming ability and then promoting their applications in structural components. PMID:27471073

  9. Liquid-solid joining of bulk metallic glasses

    NASA Astrophysics Data System (ADS)

    Huang, Yongjiang; Xue, Peng; Guo, Shu; Wu, Yang; Cheng, Xiang; Fan, Hongbo; Ning, Zhiliang; Cao, Fuyang; Xing, Dawei; Sun, Jianfei; Liaw, Peter K.

    2016-07-01

    Here, we successfully welded two bulk metallic glass (BMG) materials, Zr51Ti5Ni10Cu25Al9 and Zr50.7Cu28Ni9Al12.3 (at. %), using a liquid-solid joining process. An atomic-scale metallurgical bonding between two BMGs can be achieved. The interface has a transition layer of ~50 μm thick. The liquid-solid joining of BMGs can shed more insights on overcoming their size limitation resulting from their limited glass-forming ability and then promoting their applications in structural components.

  10. Liquid-solid joining of bulk metallic glasses

    PubMed Central

    Huang, Yongjiang; Xue, Peng; Guo, Shu; Wu, Yang; Cheng, Xiang; Fan, Hongbo; Ning, Zhiliang; Cao, Fuyang; Xing, Dawei; Sun, Jianfei; Liaw, Peter K.

    2016-01-01

    Here, we successfully welded two bulk metallic glass (BMG) materials, Zr51Ti5Ni10Cu25Al9 and Zr50.7Cu28Ni9Al12.3 (at. %), using a liquid-solid joining process. An atomic-scale metallurgical bonding between two BMGs can be achieved. The interface has a transition layer of ~50 μm thick. The liquid-solid joining of BMGs can shed more insights on overcoming their size limitation resulting from their limited glass-forming ability and then promoting their applications in structural components. PMID:27471073

  11. High temperature interaction behavior at liquid metal-ceramic interfaces

    NASA Astrophysics Data System (ADS)

    McDeavitt, S. M.; Billings, G. W.; Indacochea, J. E.

    2002-08-01

    Liquid metal/ceramic interaction experiments were undertaken at elevated temperatures with the purpose of developing reusable crucibles for melting reactive metals. The metals used in this work included zirconium (Zr), Zr-8 wt.% stainless steel, and stainless steel containing 15 wt.% Zr. The ceramic substrates include yttria, Zr carbide, and hafnium (Hf) carbide. The metal-ceramic samples were placed on top of a tungsten (W) dish. These experiments were conducted with the temperature increasing at a controlled rate until reaching set points above 2000 °C; the systems were held at the peak temperature for about five min and then cooled. The atmosphere in the furnace was argon (Ar). An outside video recording system was used to monitor the changes on heating up and cooling down. All samples underwent a post-test metallurgical examination. Pure Zr was found to react with yttria, resulting in oxygen (O) evolution at the liquid metal-ceramic interface. In addition, dissolved O was observed in the as-cooled Zr metal. Yttrium (Y) was also present in the Zr metal, but it had segregated to the grain boundaries on cooling. Despite the normal expectations for reactive wetting, no transition interface was developed, but the Zr metal was tightly bound to yttria ceramic. Similar reactions occurred between the yttria and the Zr-stainless steel alloys. Two other ceramic samples were Zr carbide and Hf carbide; both carbide substrates were wetted readily by the molten Zr, which flowed easily to the sides of the substrates. The molten Zr caused a very limited dissolution of the Zr carbide, and it reacted more strongly with the Hf carbide. These reactive wetting results are relevant to the design of interfaces and the development of reactive filler metals for the fabrication of high temperature components through metal-ceramic joining. Parameters that have a marked impact on this interface reaction include the thermodynamic stability of the substrate, the properties of the modified

  12. Magnetorotational Instability in a Rotating Liquid Metal Annulus

    SciTech Connect

    Hantao Ji; Jeremy Goodman; Akira Kageyama

    2001-03-10

    Although the magnetorotational instability (MRI) has been widely accepted as a powerful accretion mechanism in magnetized accretion disks, it has not been realized in the laboratory. The possibility of studying MRI in a rotating liquid-metal annulus (Couette flow) is explored by local and global stability analysis and magnetohydrodynamic (MHD) simulations. Stability diagrams are drawn in dimensionless parameters, and also in terms of the angular velocities at the inner and outer cylinders. It is shown that MRI can be triggered in a moderately rapidly rotating table-top apparatus, using easy-to-handle metals such as gallium. Practical issues of this proposed experiment are discussed.

  13. Upper stages using liquid propulsion and metallized propellants

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan A.

    1992-01-01

    Metallized propellants are liquid propellants with a metal additive suspended in a gelled fuel. Typically, aluminum particles are the metal additive. These propellants increase the density and/or the specific impulse of the propulsion system. Using metallized propellants for volume- and mass-constrained upper stages can deliver modest increases in performance for low Earth orbit to geosynchronous Earth orbit (LEO-GEO) and other Earth-orbital transfer missions. However, using metallized propellants for planetary missions can deliver great reductions in flight time with a single-stage, upper-stage system. Tradeoff studies comparing metallized propellant stage performance with nonmetallized upper stages and the Inertial Upper Stage (IUS) are presented. These upper stages, launched from the STS and STS-C, are both one- and two-stage vehicles that provide the added energy to send payloads to high altitude orbits and onto interplanetary trajectories that are unattainable with only the Space Transportation System (STS) and the Space Transportation System-Cargo (STS-C). The stage designs are controlled by the volume and the mass constraints of the STS and STS-C launch vehicles. The influences of the density and specific impulse increases enabled by metallized propellants are examined for a variety of different stage and propellant combinations.

  14. Excess Entropy Scaling Law for Diffusivity in Liquid Metals.

    PubMed

    Jakse, N; Pasturel, A

    2016-01-01

    Understanding how dynamic properties depend on the structure and thermodynamics in liquids is a long-standing open problem in condensed matter physics. A very simple approach is based on the Dzugutov contribution developed on model fluids in which a universal (i.e. species-independent) connection relates the pair excess entropy of a liquid to its reduced diffusion coefficient. However its application to "real" liquids still remains uncertain due to the ability of a hard sphere (HS) reference fluid used in reducing parameters to describe complex interactions that occur in these liquids. Here we use ab initio molecular dynamics simulations to calculate both structural and dynamic properties at different temperatures for a wide series of liquid metals including Al, Au, Cu, Li, Ni, Ta, Ti, Zn as well as liquid Si and B. From this analysis, we demonstrate that the Dzugutov scheme can be applied successfully if a self-consistent method to determine the packing fraction of the hard sphere reference fluid is used as well as the Carnahan-Starling approach to express the excess entropy. PMID:26862002

  15. Excess Entropy Scaling Law for Diffusivity in Liquid Metals

    PubMed Central

    Jakse, N.; Pasturel, A.

    2016-01-01

    Understanding how dynamic properties depend on the structure and thermodynamics in liquids is a long-standing open problem in condensed matter physics. A very simple approach is based on the Dzugutov contribution developed on model fluids in which a universal (i.e. species-independent) connection relates the pair excess entropy of a liquid to its reduced diffusion coefficient. However its application to “real” liquids still remains uncertain due to the ability of a hard sphere (HS) reference fluid used in reducing parameters to describe complex interactions that occur in these liquids. Here we use ab initio molecular dynamics simulations to calculate both structural and dynamic properties at different temperatures for a wide series of liquid metals including Al, Au, Cu, Li, Ni, Ta, Ti, Zn as well as liquid Si and B. From this analysis, we demonstrate that the Dzugutov scheme can be applied successfully if a self-consistent method to determine the packing fraction of the hard sphere reference fluid is used as well as the Carnahan-Starling approach to express the excess entropy. PMID:26862002

  16. Fabrication of Short Graphite Fiber Preforms for Liquid Metal Infiltration

    NASA Astrophysics Data System (ADS)

    Liu, Tingting; He, Xinbo; Liu, Qian; Zhang, Lin; Wang, Ling; Kang, Qiping; Qu, Xuanhui

    2013-06-01

    Starch-based and paraffin wax (PW)-based binders were used to fabricate short graphite fiber preforms for liquid metal infiltration. The effects of different binder components and debinding process parameters on the properties of short graphite fiber preforms were investigated. The results indicate that the graphite fiber preforms with appropriate porosity of 58-62% and relatively high compressive strength of about 2-3 MPa can be made by starch-based and PW-based binders. The graphite fiber preforms made from the PW-based binder exhibit higher compressive strength than that of the starch-based binder. Graphite fiber reinforced aluminum composites fabricated by utilizing these preforms through vacuum pressure infiltration have relatively high density of 98.5% and thermal conductivity of 186.3 W/m K, proving the applicability of the prepared preforms for liquid metal infiltration.

  17. A Liquid Metal Flume for Free Surface Magnetohydrodynamic Experiments

    SciTech Connect

    Nornberg, M.D.; Ji, H.; Peterson, J.L.; Rhoads, J.R.

    2008-08-27

    We present an experiment designed to study magnetohydrodynamic effects in free-surface channel flow. The wide aspect ratio channel (the width to height ratio is about 15) is completely enclosed in an inert atmosphere to prevent oxidization of the liquid metal. A custom-designed pump reduces entrainment of oxygen, which was found to be a problem with standard centrifugal and gear pumps. Laser Doppler Velocimetry experiments characterize velocity profiles of the flow. Various flow constraints mitigate secondary circulation and end effects on the flow. Measurements of the wave propagation characteristics in the liquid metal demonstrate the surfactant effect of surface oxides and the damping of fluctuations by a cross-channel magnetic field.

  18. Liquid-metal dip seal with pneumatic spring

    DOEpatents

    Poindexter, Allan M.

    1977-01-01

    An improved liquid-metal dip seal for sealing the annulus between rotating plugs in the reactor vessel head of a liquid-metal fast-breeder nuclear reactor has two legs of differing widths communicating under a seal blade; the wide leg is also in communication with cover gas of the reactor and the narrow leg is also in communication with an isolated plug annulus above the seal. The annulus contains inert gas which acts as a pneumatic spring. Upon increasing cover gas pressure which depresses the level in the wide leg and greatly increases the level in the narrow leg, the pneumatic spring is compressed, and resists further level changes, thus preventing radioactive cover gas from bubbling through the seal.

  19. Liquid Metal Pump Technologies for Nuclear Surface Power

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.

    2007-01-01

    Multiple liquid metal pump options are reviewed for the purpose of determining the technologies that are best suited for inclusion in a nuclear reactor thermal simulator intended to test prototypical space nuclear system components. Conduction, induction, and thermoelectric electromagnetic pumps are evaluated based on their performance characteristics and the technical issues associated incorporation into a reactor system. The thermoelectric electromagnetic pump is recommended for inclusion in the present system based on favorable quantitative and qualitative measures relative to the other options under consideration.

  20. Steam generator for liquid metal fast breeder reactor

    DOEpatents

    Gillett, James E.; Garner, Daniel C.; Wineman, Arthur L.; Robey, Robert M.

    1985-01-01

    Improvements in the design of internal components of J-shaped steam generators for liquid metal fast breeder reactors. Complex design improvements have been made to the internals of J-shaped steam generators which improvements are intended to reduce tube vibration, tube jamming, flow problems in the upper portion of the steam generator, manufacturing complexities in tube spacer attachments, thermal stripping potentials and difficulties in the weld fabrication of certain components.

  1. Liquid Metal Thermal Electric Converter bench test module

    SciTech Connect

    Lukens, L.L.; Andraka, C.E.; Moreno, J.B.

    1988-04-01

    This report describes the design, fabrication, and test of a Liquid Metal Thermal Electric Converter Bench Test Module. The work presented in this document was conducted as a part of Heat Engine Task of the US Department of Energy's (DOE) Solar Thermal Technology Program. The objective of this task is the development and evaluation of heat engine technologies applicable to distributed receiver systems, in particular, dish electric systems.

  2. Heat capacities of liquid metals above 1500 K

    NASA Technical Reports Server (NTRS)

    Margrave, J. L.

    1982-01-01

    Heat capacity data are presented for liquid transition metals for temperatures close to the melting point and for 3000, 4000, and 5000 K. The data have been obtained by summarizing the results of levitation, exploding-wire, and drop-calorimetry measurements reported in the literature and by providing analytical estimates where experimental data are not available. The data given here are useful in assigning heat loads and predicting structure survival during extreme temperature excursions caused by nuclear, laser, or particle irradiations.

  3. Proposal for Universality in the Viscosity of Metallic Liquids

    SciTech Connect

    Blodgett, M. E.; Egami, Takeshi; Nussinov, Z.; Kelton, K. F.

    2015-09-09

    The range of magnitude of the liquid viscosity, η, as a function of temperature is one of the most impressive of any physical property, changing by approximately 17 orders of magnitude from its extrapolated value at infinite temperature (ηo) to that at the glass transition temperature, Tg. We present experimental measurements of containerlessly processed metallic liquids that suggest that log(η/ηo) as a function of TA/T is a potentially universal scaled curve. In stark contrast to previous approaches, the scaling requires only two fitting parameters, which are on average predictable. The temperature TA corresponds to the onset of cooperative motion and is strongly correlated with Tg, suggesting that the processes underlying the glass transition first appear in the high temperature liquid.

  4. Proposal for Universality in the Viscosity of Metallic Liquids

    DOE PAGES

    Blodgett, M. E.; Egami, Takeshi; Nussinov, Z.; Kelton, K. F.

    2015-09-09

    The range of magnitude of the liquid viscosity, η, as a function of temperature is one of the most impressive of any physical property, changing by approximately 17 orders of magnitude from its extrapolated value at infinite temperature (ηo) to that at the glass transition temperature, Tg. We present experimental measurements of containerlessly processed metallic liquids that suggest that log(η/ηo) as a function of TA/T is a potentially universal scaled curve. In stark contrast to previous approaches, the scaling requires only two fitting parameters, which are on average predictable. The temperature TA corresponds to the onset of cooperative motion andmore » is strongly correlated with Tg, suggesting that the processes underlying the glass transition first appear in the high temperature liquid.« less

  5. Proposal for universality in the viscosity of metallic liquids

    PubMed Central

    Blodgett, M. E.; Egami, T.; Nussinov, Z.; Kelton, K. F.

    2015-01-01

    The range of magnitude of the liquid viscosity, η, as a function of temperature is one of the most impressive of any physical property, changing by approximately 17 orders of magnitude from its extrapolated value at infinite temperature (ηo) to that at the glass transition temperature, Tg. We present experimental measurements of containerlessly processed metallic liquids that suggest that log(η/ηo) as a function of TA/T is a potentially universal scaled curve. In stark contrast to previous approaches, the scaling requires only two fitting parameters, which are on average predictable. The temperature TA corresponds to the onset of cooperative motion and is strongly correlated with Tg, suggesting that the processes underlying the glass transition first appear in the high temperature liquid. PMID:26350788

  6. Proposal for universality in the viscosity of metallic liquids.

    PubMed

    Blodgett, M E; Egami, T; Nussinov, Z; Kelton, K F

    2015-01-01

    The range of magnitude of the liquid viscosity, η, as a function of temperature is one of the most impressive of any physical property, changing by approximately 17 orders of magnitude from its extrapolated value at infinite temperature (ηo) to that at the glass transition temperature, Tg. We present experimental measurements of containerlessly processed metallic liquids that suggest that log(η/ηo) as a function of TA/T is a potentially universal scaled curve. In stark contrast to previous approaches, the scaling requires only two fitting parameters, which are on average predictable. The temperature TA corresponds to the onset of cooperative motion and is strongly correlated with Tg, suggesting that the processes underlying the glass transition first appear in the high temperature liquid. PMID:26350788

  7. Proposal for universality in the viscosity of metallic liquids

    NASA Astrophysics Data System (ADS)

    Blodgett, M. E.; Egami, T.; Nussinov, Z.; Kelton, K. F.

    2015-09-01

    The range of magnitude of the liquid viscosity, η, as a function of temperature is one of the most impressive of any physical property, changing by approximately 17 orders of magnitude from its extrapolated value at infinite temperature (ηo) to that at the glass transition temperature, Tg. We present experimental measurements of containerlessly processed metallic liquids that suggest that log(η/ηo) as a function of TA/T is a potentially universal scaled curve. In stark contrast to previous approaches, the scaling requires only two fitting parameters, which are on average predictable. The temperature TA corresponds to the onset of cooperative motion and is strongly correlated with Tg, suggesting that the processes underlying the glass transition first appear in the high temperature liquid.

  8. Complaint liquid metal electrodes for dielectric elastomer actuators

    NASA Astrophysics Data System (ADS)

    Finkenauer, Lauren R.; Majidi, Carmel

    2014-03-01

    This work presents a liquid-phase metal electrode to be used with poly(dimethylsiloxane) (PDMS) for a dielectric elastomer actuator (DEA). DEAs are favorable for soft-matter applications where high efficiency and response times are desirable. A consistent challenge faced during the fabrication of these devices is the selection and deposition of electrode material. While numerous designs have been demonstrated with a variety of conductive elastomers and greases, these materials have significant and often intrinsic shortcomings, e.g. low conductivity, hysteresis, incapability of large deformations, and complex fabrication requirements. The liquid metal alloy eutectic Gallium-Indium (EGaIn) is a promising alternative to existing compliant electrodes, having both high conductivity and complete soft-matter functionality. The liquid electrode shares almost the same electrical conductivity as conventional metal wiring and provides no mechanical resistance to bending or stretching of the DEA. This research establishes a straightforward and effective method for quickly depositing EGaIn electrodes, which can be adapted for batch fabrication, and demonstrates the successful actuation of sample curved cantilever elastomer actuators using these electrodes. As with the vast majority of electrostatically actuated elastomer devices, the voltage requirements for these curved DEAs are still quite significant, though modifications to the fabrication process show some improved electrical properties. The ease and speed with which this method can be implemented suggests that the development of a more electronically efficient device is realistic and worthwhile.

  9. Ultrasound Velocity Measurement in a Liquid Metal Electrode.

    PubMed

    Perez, Adalberto; Kelley, Douglas H

    2015-01-01

    A growing number of electrochemical technologies depend on fluid flow, and often that fluid is opaque. Measuring the flow of an opaque fluid is inherently more difficult than measuring the flow of a transparent fluid, since optical methods are not applicable. Ultrasound can be used to measure the velocity of an opaque fluid, not only at isolated points, but at hundreds or thousands of points arrayed along lines, with good temporal resolution. When applied to a liquid metal electrode, ultrasound velocimetry involves additional challenges: high temperature, chemical activity, and electrical conductivity. Here we describe the experimental apparatus and methods that overcome these challenges and allow the measurement of flow in a liquid metal electrode, as it conducts current, at operating temperature. Temperature is regulated within ±2 °C using a Proportional-Integral-Derivative (PID) controller that powers a custom-built furnace. Chemical activity is managed by choosing vessel materials carefully and enclosing the experimental setup in an argon-filled glovebox. Finally, unintended electrical paths are carefully prevented. An automated system logs control settings and experimental measurements, using hardware trigger signals to synchronize devices. This apparatus and these methods can produce measurements that are impossible with other techniques, and allow optimization and control of electrochemical technologies like liquid metal batteries.

  10. Theoretical Studies of the Surface Tension of Liquid Metal System

    NASA Technical Reports Server (NTRS)

    Stroud, D. G.; Shih, W. H.

    1985-01-01

    A major goal of this project is to understand the surface tension and other thermophysical properties of liquid metals and alloys from a fundamental viewpoint. The approach is to calculate these quantities by a first principles technique which combines the statistical-mechanical theory of the liquid state with an electronic pseudopotential theory of electrons in metals. The inhomogeneity of the surface is treated using an ionic-density-functional formalism developed with the support of NASA. Of particular interest are the variation of surface tension with temperature and impurity concentration: such variations strongly influence the types of convection which make take place in a low-gravity environment. Some progress has already been achieved in computing the reduction of surface tension due to the presence of low-surface-tension impurities, and the corresponding surface segregation of such impurities. In the coming year, it is planned to concentrate on the surface properties of materials of particular interest to the MSA program: Si, Ga and GaSn alloys. An additional goal is to gain some theoretical understanding of the high temperature thermophysical properties of liquid metals, particularly high melting point materials which have not been studied extensively from a theoretical viewpoint.

  11. On Pressure Wave Simulations in Liquid Metal Neutron Source Targets

    NASA Astrophysics Data System (ADS)

    Fetzer, Jana R.; Class, Andreas

    2014-11-01

    Sound waves generated by fluid flow at low Mach numbers is associated with separated scales and thus with difficulties to construct efficient numerical methods for their approximation. One method is the Multi Pressure Variables (MPV) approach introduced for aero-acoustic applications. The MPV approach is based on a single time scale multiple space scale asymptotic analysis derived for subsonic flow by an asymptotic series expansion in the Mach-number. Distinguished are the flow and acoustic length scales resulting in three pressure contribution, i.e. thermodynamic, acoustic and dynamic pressure which are discretized on numerical meshes of different resolution. We propose to apply MPV to analyse liquid metal cooled spallation targets with a pulsed proton beams. These targets are operating in high power neutron sources for fundamental research. The nearly instantaneous heating of the liquid metal results in volumetric expansion of inertia confined liquid and thus to high pressure waves, which represent a major lifetime limiting thread. Our development accompanies design activities for the META:LIC (MEgawatt TArget: Lead bIsmuth Cooled) target proposed for the European Spallation Source.

  12. Nanoparticulate gellants for metallized gelled liquid hydrogen with aluminum

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan; Starkovich, John; Adams, Scott

    1996-01-01

    Gelled liquid hydrogen was experimentally formulated using sol-gel technology. As a follow-on to work with cryogenic simulants, hydrogen was gelled with an alkoxide material: BTMSE. Initial results demonstrated that gellants with a specific surface area of 1000 m(exp 2)/g could be repeatably fabricated. Gelled hexane and metallized gelled hexane (with 13.8-wt% Al) were produced. Propellant settling testing was conducted for acceleration levels of 2 to 10 times normal gravity and a minimum gellant percentage was determined for stable gelled hexane and metalized gelled hexane. A cryogenic capillary rheometer was also designed, constructed, and used to determine the viscosity of gelled hydrogen. Small volumes of liquid hydrogen were gelled with a 7- to 8-wt% gellant level. The gelled H2 viscosity was 1.5 to 3.7 times that of liquid hydrogen: 0.048 to 0.116 mPa-s versus 0.03 mPa-s for liquid H2 (at 16 K and approximately 1 atm pressure).

  13. Thermal diffusion in metal-sulfide liquids - Early results

    NASA Technical Reports Server (NTRS)

    Jones, J. H.; Walker, D.

    1991-01-01

    Experiments were carried out to evaluate the Soret effect in liquid Fe-Ni-S-P alloys in order to gain a better understanding of the physical and thermodynamic properties of metallic liquids and to assess the possibility of systematic errors in Czochralski growth techniques. The metal-sulfide liquids were found to show a substantial Soret effect and, contrary to previous expectation, can be as large as that seen in the silicate system. The segregation is largely produced by S-Fe interactions. The P redistribution occurs to reduce activity gradients in P consequent upon S gradients, and P segregation can be approximately predicted in Fe-Ni-S liquids using the activity model of Jones and Malvin (1990). It is inferred that the sense of the Soret segregation, with P going to the cold end and S going to the hot end, is in accordance with the prediction of Malvin et al. (1986), who speculated that the crystal-pulling experiments of Sellamuthu and Goldstein (1985) was influenced by the Soret effect.

  14. Experimental determination of the Si isotope fractionation factor between liquid metal and liquid silicate

    NASA Astrophysics Data System (ADS)

    Hin, Remco C.; Fitoussi, Caroline; Schmidt, Max W.; Bourdon, Bernard

    2014-02-01

    The conditions of core formation and the abundances of the light elements in Earth's core remain debated. Silicon isotope fractionation provides a tool contributing to this subject. We present experimentally determined Si isotope fractionation factors between liquid metal and liquid silicate at 1450 °C and 1750 °C, which allow calibrating the temperature dependence of Si isotope fractionation. Experiments were performed in a centrifuging piston cylinder at 1 GPa, employing both graphite and MgO capsules. Tin was used to lower the melting temperature of the metal alloys for experiments performed at 1450 °C. Tests reveal that neither Sn nor C significantly affects Si isotope fractionation. An alkaline fusion technique was employed to dissolve silicate as well as metal phases prior to ion exchange chemistry and mass spectrometric analysis. The results show that metal is consistently enriched in light isotopes relative to the silicate, yielding average metal-silicate fractionation factors of -1.48±0.08‰ and -1.11±0.14‰ at 1450 °C and 1750 °C, respectively. The temperature dependence of equilibrium Si isotope fractionation between metal and silicate can thus be described as Δ30SiMetal-Silicate=-4.42(±0.05)×106/T2. The Si isotope equilibrium fractionation is thus about 1.7 times smaller than previously proposed on the basis of experiments. A consequence of this smaller fractionation is that the calculated difference between the Si isotope composition of the bulk Earth and that of the bulk silicate Earth generated by core formation is smaller than previously thought. It is therefore increasingly difficult to match the Si isotope composition of the bulk silicate Earth with that of chondrites for metal-silicate equilibration temperatures above ∼2500 K. This suggests that Si isotopes were more sensitive to the early stages of core formation when low oxygen fugacities allowed significant incorporation of Si into metal.

  15. NGNP Process Heat Utilization: Liquid Metal Phase Change Heat Exchanger

    SciTech Connect

    Piyush Sabharwall; Mike Patterson; Vivek Utgikar; Fred Gunnerson

    2008-09-01

    One key long-standing issue that must be overcome to fully realize the successful growth of nuclear power is to determine other benefits of nuclear energy apart from meeting the electricity demands. The Next Generation Nuclear Plant (NGNP) will most likely be producing electricity and heat for the production of hydrogen and/or oil retrieval from oil sands and oil shale to help in our national pursuit of energy independence. For nuclear process heat to be utilized, intermediate heat exchange is required to transfer heat from the NGNP to the hydrogen plant or oil recovery field in the most efficient way possible. Development of nuclear reactor - process heat technology has intensified the interest in liquid metals as heat transfer media because of their ideal transport properties. Liquid metal heat exchangers are not new in practical applications. An important rational for considering liquid metals is the potential convective heat transfer is among the highest known. Thus explains the interest in liquid metals as coolant for intermediate heat exchange from NGNP. For process heat it is desired that, intermediate heat exchangers (IHX) transfer heat from the NGNP in the most efficient way possible. The production of electric power at higher efficiency via the Brayton Cycle, and hydrogen production, requires both heat at higher temperatures and high effectiveness compact heat exchangers to transfer heat to either the power or process cycle. Compact heat exchangers maximize the heat transfer surface area per volume of heat exchanger; this has the benefit of reducing heat exchanger size and heat losses. High temperature IHX design requirements are governed in part by the allowable temperature drop between the outlet and inlet of the NGNP. In order to improve the characteristics of heat transfer, liquid metal phase change heat exchangers may be more effective and efficient. This paper explores the overall heat transfer characteristics and pressure drop of the phase change

  16. Nanostructured elastomers: From smectic liquid crystals to noble metal nanocomposites

    NASA Astrophysics Data System (ADS)

    Lentz, Daniel M.

    method of the nanoinfusion process has been demonstrated that displays significant enhancements to nanoparticle concentration (volume fraction) in thermoplastic polyurethane elastomers (TPUs), as well as decreased average particle size. This latter method involves the creation of an interpenetrating layer of a functionalized monomer via an infusion-polymerization approach. Said functional group is subsequently used to reduce the metal precursor as it is infused using the same processing step as the above method. TEM images show significantly higher volume fraction of nanoparticles using this method, providing the potential for more drastic improvements in optical and other properties. Another material of interest for synthesis of nanocomposites are liquid crystalline elastomers. Liquid crystalline elastomers have received attention for their unique mechanical properties, which underlie their potential for use in applications such as artificial muscles (due to the electroclinic effect) and constrained vibration damping applications (due to their broad peak in tan delta versus either temperature or frequency). An interesting feature observed in the liquid crystalline elastomers produced in our groups is the formation of a neck in the sample under uniaxial tension. The mechanical response of these smectic main-chain liquid crystalline elastomers (MCLCE) has been characterized at a variety of strain rates and temperatures in order to understand the cause of the observed neck formation. A well-defined yield stress is observed at a critical strain that is essentially independent of strain rate, followed by necking and cold-drawing. Cold-drawing is rarely observed in liquid crystalline elastomers, but we believe that it is observed in MCLCE due to the unfolding of hairpin chains at the start of the polydomain to monodomain transition. A neck forms as the hairpins straighten out, resulting in a decreased cross-sectional area that promotes yielding. Infusions of both metal

  17. Liquid Metals: Stretchable, High-k Dielectric Elastomers through Liquid-Metal Inclusions (Adv. Mater. 19/2016).

    PubMed

    Bartlett, Michael D; Fassler, Andrew; Kazem, Navid; Markvicka, Eric J; Mandal, Pratiti; Majidi, Carmel

    2016-05-01

    An all-soft-matter composite consisting of liquid metal microdroplets embedded in a soft elastomer matrix is presented by C. Majidi and co-workers on page 3726. This composite exhibits a high dielectric constant while maintaining exceptional elasticity and compliance. The image shows the composite's microstructure captured by 3D X-ray imaging using a nano-computed tomographic scanner. PMID:27167031

  18. A handy liquid metal based electroosmotic flow pump.

    PubMed

    Gao, Meng; Gui, Lin

    2014-06-01

    A room temperature liquid metal based electroosmotic flow (EOF) pump has been proposed in this work. This low-cost EOF pump is convenient for both fabrication and integration. It utilizes polydimethylsiloxane (PDMS) microchannels filled with the liquid-metal as non-contact pump electrodes. The electrode channels are fabricated symmetrically to both sides of the pumping channel, having no contact with the pumping channel. To test the pumping performance of the EOF pump, the mean flow velocities of the fluid (DI water) in the EOF pumps were experimentally measured by tracing the fluorescent microparticles in the flow. To provide guidance for designing a low voltage EOF pump, parametric studies on dimensions of the electrode and pumping channels were performed in this work. According to the experimental results, the pumping speed can reach 5.93 μm s(-1) at a driving voltage of only 1.6 V, when the gap between the electrode and the pumping channel is 20 μm. Injecting a room temperature liquid metal into microchannels can provide a simple, rapid, low-cost but accurately self-aligned way to fabricate microelectrodes for EOF pumps, which is a promising method to achieve the miniaturization and integration of the EOF pump in microfluidic systems. The non-contact liquid electrodes have no influence on the fluid in the pumping channel when pumping, reducing Joule heat generation and preventing gas bubble formation at the surface of electrodes. The pump has great potential to drive a wide range of fluids, such as drug reagents, cell suspensions and biological macromolecule solutions.

  19. A handy liquid metal based electroosmotic flow pump.

    PubMed

    Gao, Meng; Gui, Lin

    2014-06-01

    A room temperature liquid metal based electroosmotic flow (EOF) pump has been proposed in this work. This low-cost EOF pump is convenient for both fabrication and integration. It utilizes polydimethylsiloxane (PDMS) microchannels filled with the liquid-metal as non-contact pump electrodes. The electrode channels are fabricated symmetrically to both sides of the pumping channel, having no contact with the pumping channel. To test the pumping performance of the EOF pump, the mean flow velocities of the fluid (DI water) in the EOF pumps were experimentally measured by tracing the fluorescent microparticles in the flow. To provide guidance for designing a low voltage EOF pump, parametric studies on dimensions of the electrode and pumping channels were performed in this work. According to the experimental results, the pumping speed can reach 5.93 μm s(-1) at a driving voltage of only 1.6 V, when the gap between the electrode and the pumping channel is 20 μm. Injecting a room temperature liquid metal into microchannels can provide a simple, rapid, low-cost but accurately self-aligned way to fabricate microelectrodes for EOF pumps, which is a promising method to achieve the miniaturization and integration of the EOF pump in microfluidic systems. The non-contact liquid electrodes have no influence on the fluid in the pumping channel when pumping, reducing Joule heat generation and preventing gas bubble formation at the surface of electrodes. The pump has great potential to drive a wide range of fluids, such as drug reagents, cell suspensions and biological macromolecule solutions. PMID:24706096

  20. Numerical Modeling of Inclusion Behavior in Liquid Metal Processing

    NASA Astrophysics Data System (ADS)

    Bellot, Jean-Pierre; Descotes, Vincent; Jardy, Alain

    2013-09-01

    Thermomechanical performance of metallic alloys is directly related to the metal cleanliness that has always been a challenge for metallurgists. During liquid metal processing, particles can grow or decrease in size either by mass transfer with the liquid phase or by agglomeration/fragmentation mechanisms. As a function of numerical density of inclusions and of the hydrodynamics of the reactor, different numerical modeling approaches are proposed; in the case of an isolated particle, the Lagrangian technique coupled with a dissolution model is applied, whereas in the opposite case of large inclusion phase concentration, the population balance equation must be solved. Three examples of numerical modeling studies achieved at Institut Jean Lamour are discussed. They illustrate the application of the Lagrangian technique (for isolated exogenous inclusion in titanium bath) and the Eulerian technique without or with the aggregation process: for precipitation and growing of inclusions at the solidification front of a Maraging steel, and for endogenous inclusions in the molten steel bath of a gas-stirred ladle, respectively.

  1. Calcium-Antimony Alloys as Electrodes for Liquid Metal Batteries

    SciTech Connect

    Ouchi, T; Kim, H; Ning, XH; Sadoway, DR

    2014-08-08

    The performance of a calcium-antimony (Ca-Sb) alloy serving as the positive electrode in a Ca vertical bar vertical bar Sb liquid metal battery was investigated in an electrochemical cell, Ca(in Bi) vertical bar LiCl-NaCl-CaCl2 vertical bar Ca(in Sb). The equilibrium potential of the Ca-Sb electrode was found to lie on the interval, 1.2-0.95 V versus Ca, in good agreement with electromotive force (emf) measurements in the literature. During both alloying and dealloying of Ca at the Sb electrode, the charge transfer and mass transport at the interface are facile enough that the electrode potential varies linearly from 0.95 to 0.75 V vs Ca(s) as current density varies from 50 to 500 mA cm(-2). The discharge capacity of the Ca vertical bar vertical bar Sb cells increases as the operating temperature increases due to the higher solubility and diffusivity of Ca in Sb. The cell was successfully cycled with high coulombic efficiency (similar to 100%) and small fade rate (<0.01% cycle(-1)). These data combined with the favorable costs of these metals and salts make the Ca vertical bar vertical bar Sb liquid metal battery attractive for grid-scale energy storage. (C) The Author(s) 2014. Published by ECS. All rights reserved.

  2. Metal ion adsorption at the ionic liquid-mica interface

    NASA Astrophysics Data System (ADS)

    McDonald, Samila; Elbourne, Aaron; Warr, Gregory G.; Atkin, Rob

    2015-12-01

    Mica has been employed in many studies of ionic liquid (IL) interfaces on account of its atomic smoothness and well defined surface properties. However, until now it has been unclear whether ions dissolved in ILs can compete with the IL cation and adsorb to mica charge sites. In this work amplitude modulated atomic force microscopy (AM-AFM) has been used to probe metal ion adsorption at the interface of mica with propylammonium nitrate (PAN), a room temperature IL. Lithium, sodium, potassium, magnesium and calcium nitrate salts were added to PAN at a concentration of ~60 mM. Aluminum nitrate was also investigated, but only at 5 mM because its solubility in PAN is much lower. The AM-AFM images obtained when the metal ions were present are strikingly different to that of pure PAN, indicating that the ions compete effectively with the propylammonium cation and adsorb to negatively charged sites on the mica surface despite their much lower concentration. This is a consequence of electrostatic attractions between the mica charge sites and the metal ions being significantly stronger than for the propylammonium cation; compared to the metal ions the propylammonium charged group is relatively constrained sterically. A distinct honeycomb pattern is noted for the PAN + Al3+ system, less obviously for the divalent ions and not at all for monovalent ions. This difference is attributed to the strength of electrostatic interactions between metal ions and mica charge sites increasing with the ion charge, which means that divalent and (particularly) trivalent ions are located more precisely above the charged sites of the mica lattice. The images obtained allow important distinctions between metal ion adsorption at mica-water and mica-PAN interfaces to be made.Mica has been employed in many studies of ionic liquid (IL) interfaces on account of its atomic smoothness and well defined surface properties. However, until now it has been unclear whether ions dissolved in ILs can compete

  3. Zn Penetration in Liquid Metal Embrittled TWIP Steel

    NASA Astrophysics Data System (ADS)

    Kang, Heeseung; Cho, Lawrence; Lee, Changwook; De Cooman, Bruno C.

    2016-06-01

    Hot-dip Zn-coated high manganese twinning-induced plasticity (TWIP) steel is sensitive to liquid metal embrittlement (LME). The microstructure of Zn-coated TWIP steel after brittle fracture at 1123 K (850 °C) was investigated. The grain boundaries at the tip of the Zn penetration were analyzed by electron microscopy and atom probe tomography. Γ-(Fe,Mn)3Zn10 was found at the tip of the Zn penetration in the TWIP steel, implying that liquid Fe- and Mn-saturated Zn-rich alloy had percolated along the grain boundaries to the tip of the Zn penetration. Evidence for extensive Zn grain boundary diffusion ahead of the Zn-rich alloy percolation path was also observed. Both the Stoloff-Johnson-Westwood-Kamdar model and the Krishtal-Gordon-An model for LME crack formation are compatible with the present in-depth microanalysis of the Zn penetration.

  4. ‘Crystal Genes’ in Metallic Liquids and Glasses

    DOE PAGES

    Sun, Yang; Zhang, Feng; Ye, Zhuo; Zhang, Yue; Fang, Xiaowei; Ding, Zejun; Wang, Cai-Zhuang; Mendelev, Mikhail I.; Ott, Ryan T.; Kramer, Matthew J.; et al

    2016-03-31

    We analyze the underlying structural order that transcends liquid, glass and crystalline states in metallic systems. A genetic algorithm is applied to search for the most common energetically favorable packing motifs in crystalline structures. These motifs are in turn compared to the observed packing motifs in the actual liquid or glass structures using a cluster-alignment method. Using this method, we have revealed the nature of the short-range order in Cu64Zr36 glasses. More importantly, we identified a novel structural order in the Al90Sm10 system. In addition, our approach brings new insight into understanding the origin of vitrification and describing mesoscopic order-disordermore » transitions in condensed matter systems.« less

  5. Breakdown voltage of metal-oxide resistors in liquid argon

    SciTech Connect

    Bagby, L. F.; Gollapinni, S.; James, C. C.; Jones, B. J.P.; Jostlein, H.; Lockwitz, S.; Naples, D.; Raaf, J. L.; Rameika, R.; Schukraft, A.; Strauss, T.; Weber, M. S.; Wolbers, S. A.

    2014-11-07

    We characterized a sample of metal-oxide resistors and measured their breakdown voltage in liquid argon by applying high voltage (HV) pulses over a 3 second period. This test mimics the situation in a HV-divider chain when a breakdown occurs and the voltage across resistors rapidly rise from the static value to much higher values. All resistors had higher breakdown voltages in liquid argon than their vendor ratings in air at room temperature. Failure modes range from full destruction to coating damage. In cases where breakdown was not catastrophic, subsequent breakdown voltages were lower in subsequent measuring runs. One resistor type withstands 131 kV pulses, the limit of the test setup.

  6. Impinging jet separators for liquid metal magnetohydrodynamic power cycles

    NASA Technical Reports Server (NTRS)

    Bogdanoff, D. W.

    1973-01-01

    In many liquid metal MHD power, cycles, it is necessary to separate the phases of a high-speed liquid-gas flow. The usual method is to impinge the jet at a glancing angle against a solid surface. These surface separators achieve good separation of the two phases at a cost of a large velocity loss due to friction at the separator surface. This report deals with attempts to greatly reduce the friction loss by impinging two jets against each other. In the crude impinging jet separators tested to date, friction losses were greatly reduced, but the separation of the two phases was found to be much poorer than that achievable with surface separators. Analyses are presented which show many lines of attack (mainly changes in separator geometry) which should yield much better separation for impinging jet separators).

  7. Nanostructure operations by means of the liquid metal ion sourcesa)

    NASA Astrophysics Data System (ADS)

    Gasanov, I. S.; Gurbanov, I. I.

    2012-02-01

    Characteristics of a disperse phase of liquid metal ion source on the basis of various working substances are investigated. It is revealed that generation of the charged particles occurs in the threshold image and is simultaneously accompanied by excitation of capillary instability on a surface of the emitter. The majority of particles has the size about 2 nm (Sn) and a specific charge of 5 × 104 C/kg. If the working liquid possesses high viscosity (Ni), generation of nanodroplets does not occur. Gold nanoparticles are used for deposition on a surface of quartz cantilevers with the purpose of increase in sensitivity of biosensors and on an external surface of carbon nanotubes for creation pressure sensors. By means of an ion source nanostructures can be etched on a flat surface of conductive materials without difficult ion optics.

  8. ‘Crystal Genes’ in Metallic Liquids and Glasses

    NASA Astrophysics Data System (ADS)

    Sun, Yang; Zhang, Feng; Ye, Zhuo; Zhang, Yue; Fang, Xiaowei; Ding, Zejun; Wang, Cai-Zhuang; Mendelev, Mikhail I.; Ott, Ryan T.; Kramer, Matthew J.; Ho, Kai-Ming

    2016-03-01

    We analyze the underlying structural order that transcends liquid, glass and crystalline states in metallic systems. A genetic algorithm is applied to search for the most common energetically favorable packing motifs in crystalline structures. These motifs are in turn compared to the observed packing motifs in the actual liquid or glass structures using a cluster-alignment method. Using this method, we have revealed the nature of the short-range order in Cu64Zr36 glasses. More importantly, we identified a novel structural order in the Al90Sm10 system. In addition, our approach brings new insight into understanding the origin of vitrification and describing mesoscopic order-disorder transitions in condensed matter systems.

  9. ‘Crystal Genes’ in Metallic Liquids and Glasses

    PubMed Central

    Sun, Yang; Zhang, Feng; Ye, Zhuo; Zhang, Yue; Fang, Xiaowei; Ding, Zejun; Wang, Cai-Zhuang; Mendelev, Mikhail I.; Ott, Ryan T.; Kramer, Matthew J.; Ho, Kai-Ming

    2016-01-01

    We analyze the underlying structural order that transcends liquid, glass and crystalline states in metallic systems. A genetic algorithm is applied to search for the most common energetically favorable packing motifs in crystalline structures. These motifs are in turn compared to the observed packing motifs in the actual liquid or glass structures using a cluster-alignment method. Using this method, we have revealed the nature of the short-range order in Cu64Zr36 glasses. More importantly, we identified a novel structural order in the Al90Sm10 system. In addition, our approach brings new insight into understanding the origin of vitrification and describing mesoscopic order-disorder transitions in condensed matter systems. PMID:27030071

  10. Directed liquid phase assembly of highly ordered metallic nanoparticle arrays

    SciTech Connect

    Wu, Yueying; Dong, Nanyi; Fu, Shaofang; Fowlkes, Jason D.; Kondic, Lou; Vincenti, Maria A.; de Ceglia, Domenico; Rack, Philip D.

    2014-04-01

    Directed assembly of nanomaterials is a promising route for the synthesis of advanced materials and devices. We demonstrate the directed-assembly of highly ordered two-dimensional arrays of hierarchical nanostructures with tunable size, spacing and composition. The directed assembly is achieved on lithographically patterned metal films that are subsequently pulse-laser melted; during the brief liquid lifetime, the pattened nanostructures assemble into highly ordered primary and secondary nanoparticles, with sizes below that which was originally patterned. Complementary fluid-dynamics simulations emulate the resultant patterns and show how the competition of capillary forces and liquid metal–solid substrate interaction potential drives the directed assembly. Lastly, as an example of the enhanced functionality, a full-wave electromagnetic analysis has been performed to identify the nature of the supported plasmonic resonances.

  11. Directed liquid phase assembly of highly ordered metallic nanoparticle arrays

    DOE PAGES

    Wu, Yueying; Dong, Nanyi; Fu, Shaofang; Fowlkes, Jason D.; Kondic, Lou; Vincenti, Maria A.; de Ceglia, Domenico; Rack, Philip D.

    2014-04-01

    Directed assembly of nanomaterials is a promising route for the synthesis of advanced materials and devices. We demonstrate the directed-assembly of highly ordered two-dimensional arrays of hierarchical nanostructures with tunable size, spacing and composition. The directed assembly is achieved on lithographically patterned metal films that are subsequently pulse-laser melted; during the brief liquid lifetime, the pattened nanostructures assemble into highly ordered primary and secondary nanoparticles, with sizes below that which was originally patterned. Complementary fluid-dynamics simulations emulate the resultant patterns and show how the competition of capillary forces and liquid metal–solid substrate interaction potential drives the directed assembly. Lastly, asmore » an example of the enhanced functionality, a full-wave electromagnetic analysis has been performed to identify the nature of the supported plasmonic resonances.« less

  12. Present status of liquid metal research for a fusion reactor

    NASA Astrophysics Data System (ADS)

    Tabarés, Francisco L.

    2016-01-01

    Although the use of solid materials as targets of divertor plasmas in magnetic fusion research is accepted as the standard solution for the very challenging issue of power and particle handling in a fusion reactor, a generalized feeling that the present options chosen for ITER will not represent the best choice for a reactor is growing up. The problems found for tungsten, the present selection for the divertor target of ITER, in laboratory tests and in hot plasma fusion devices suggest so. Even in the absence of the strong neutron irradiation expected in a reactor, issues like surface melting, droplet ejection, surface cracking, dust generation, etc., call for alternative solutions in a long pulse, high efficient fusion energy-producing continuous machine. Fortunately enough, decades of research on plasma facing materials based on liquid metals (LMs) have produced a wealth of appealing ideas that could find practical application in the route to the realization of a commercial fusion power plant. The options presently available, although in a different degree of maturity, range from full coverage of the inner wall of the device with liquid metals, so that power and particle exhaust together with neutron shielding could be provided, to more conservative combinations of liquid metal films and conventional solid targets basically representing a sort of high performance, evaporative coating for the alleviation of the surface degradation issues found so far. In this work, an updated review of worldwide activities on LM research is presented, together with some open issues still remaining and some proposals based on simple physical considerations leading to the optimization of the most conservative alternatives.

  13. Thermal Control Using Liquid-Metal Bridge Switches

    NASA Technical Reports Server (NTRS)

    Hirsa, Amir H.; Olles, Joseph; Tilger, Christopher

    2013-01-01

    A short term effort (3-months) was undertaken to demonstrate the feasibility of a novel method to locally control the heat transfer rate and demonstrate the potential to achieve a turndown ratio of approximately 10:1. The technology had to be demonstrated to be at a TRL of 2-3, with a plan to advance it to a TRL 5-6. Here, we show that the concept recently developed in our laboratory, namely the pinned-contact, double droplet switch made by overfilling a hole drilled in a suitable substrate can be implemented with a low-melting temperature metal. When toggled near a second substrate, a liquid bridge can be reversibly connected or disconnected, on demand. We have shown experimentally that liquid-metal bridge switches can be made from gallium with a suitable choice of substrate materials, activation strategies, and control techniques. Individual as well as arrays of gallium bridge switches were shown to be feasible and can be robustly controlled. The very short response time of the bridge connection and disconnection (on the order of 1 millisecond) provides for utility in a wide range of applications. The liquid bridge switches may be controlled actively or passively. We have shown through computations and analysis that liquid bridge switches provide locally large turndown ratios (on the order of 103:1), so a relatively sparse packing of them would be needed to obtain the desired turndown ratio of 10:1. For the laboratory demonstrations, pressure activation was utilized. Simple designs for a passive control strategy are presented which are highly attractive for several reasons, including i) large turndown ratio, ii) no solid-moving parts, and iii) stable operation. Finally, we note that passive systems do not require any electronics for their control. This along with the relatively small molecular weight of candidate materials for the system, makes for a robust design outside of Earth?s magnetic field, where spacecraft are subject to significant radiation bombardment.

  14. Optical properties and emissivities of liquid metals and alloys

    NASA Technical Reports Server (NTRS)

    Krishnan, Shankar; Nordine, Paul C.

    1993-01-01

    This paper presents the results from our on-going program to investigate the optical properties of liquid metals and alloys at elevated temperatures. Ellipsometric and polarimetric techniques have been used to investigate the optical properties of materials in the 1000 - 3000 K temperature range and in the 0.3 - 0.1 mu m wavelength range. The ellipsometric and polarimetric techniques are described and the characteristics of the instruments are presented. The measurements are conducted by reflecting a polarized laser beam from an electromagnetically levitated liquid metal or alloy specimen. A Rotating Analyzer Ellipsometer (RAE) or a four-detector Division-of-Amplitude Photopolarimeter (DOAP) is used to determine the polarimetric properties of the light reflected at an angle of incidence of approximately 68 deg. Optical properties of the specimen which are calculated from these measurements include the index of refraction, extinction coefficient, normal spectral emissivity, and spectral hemispherical emissivity. These properties have been determined at various wavelengths and temperatures for liquid Ag, Al, Au, Cu, Nb, Ni, Pd, Pt, Si, Ti, Ti-Al alloys, U, and Zr. We also describe new experiments using pulsed-dye laser spectroscopic ellipsometry for studies of the wavelength dependence of the emissivities and optical properties of materials at high temperature. Preliminary results are given for liquid Al. The application of four-detector polarimetry for rapid determination of surface emissivity and true temperature is also described. Characteristics of these devices are presented. An example of the accuracy of this instrument in measurements of the melting point of zirconium is illustrated.

  15. Solid Metal-Liquid Metal Partitioning of Pt, Re, and Os: The Effect of Carbon

    NASA Technical Reports Server (NTRS)

    Chabot, N. L.; Campbell, A. J.; Humayun, M.

    2004-01-01

    If the measured Os isotopic ratios are a signature from the Earth's outer core, understanding them is a unique opportunity to understand more about the Earth's core. The distribution of elements between the Earth's solid inner core and the liquid outer core will depend on their solid metal-liquid metal partition coefficients (D). Solid metal-liquid metal partitioning data are loosely consistent with the needed fractionations between Re-Os and Pt-Os to account for the Os isotopic signature; D(Os) is greater than both D(Re) and D(Pt), and the magnitude of the partition coefficients are similar to those needed [e.g. 7, 8]. The pressure in the core, the composition of the core, and the crystal structure of the solid Fe alloy in the inner core may influence the specific values of the partition coefficients. It may thus be possible to use these sensitivities of the partition coefficients to gain insight into the conditions within the Earth's core. In this abstract, we focus on the compositional influence of C, a potential component of the light element in the Earth's core [9], on the partitioning behaviors of Pt, Re, and Os.

  16. Passive cooling safety system for liquid metal cooled nuclear reactors

    DOEpatents

    Hunsbedt, Anstein; Boardman, Charles E.; Hui, Marvin M.; Berglund, Robert C.

    1991-01-01

    A liquid metal cooled nuclear reactor having a passive cooling system for removing residual heat resulting from fuel decay during reactor shutdown. The passive cooling system comprises a plurality of partitions surrounding the reactor vessel in spaced apart relation forming intermediate areas for circulating heat transferring fluid which remove and carry away heat from the reactor vessel. The passive cooling system includes a closed primary fluid circuit through the partitions surrounding the reactor vessel and a partially adjoining secondary open fluid circuit for carrying transferred heat out into the atmosphere.

  17. Laser-Driven Corrugation Instability of Liquid Metal Surfaces

    NASA Astrophysics Data System (ADS)

    Keilmann, Fritz

    1983-12-01

    During intense CO2-laser irradiation deep corrugations build up on liquid metals such as Hg, In, Sn, Al, and Pb. Spacing, orientation, growth, and decay of the corrugations are studied, by visible light diffraction; support is found for a model of stimulated scattering where the incident light parametrically decays into both the surface corrugation and a surface plasmon. Thermal evaporation supplies the nonlinearity. The instability provides polarization-dependent absorption and can be expected in laser-metalworking and laser-plasma situations.

  18. Liquid-Metal Pump Technologies for Nuclear Surface Power

    NASA Technical Reports Server (NTRS)

    Polzin, K. A.

    2007-01-01

    Multiple liquid-metal pump options are reviewed for the purpose of determining the technologies that are best suited for inclusion in a nuclear reactor thermal simulator intended to test prototypical space nuclear system components. Conduction, induction, and thermoelectric electromagnetic pumps are evaluated based on their performance characteristics and the technical issues associated with incorporation into a reactor system. The thermoelectric pump is recommended for inclusion in the planned system at NASA MSFC based on its relative simplicity, low power supply mass penalty, flight heritage, and the promise of increased pump efficiency over earlier flight pump designs through the use of skutterudite thermoelectric elements.

  19. Liquid-metal atomization for hot working preforms

    NASA Technical Reports Server (NTRS)

    Grant, N. J.; Pelloux, R. M.

    1974-01-01

    Rapid quenching of a liquid metal by atomization or splat cooling overcomes the major limitation of most solidification processes, namely, the segregation of alloying elements, impurities, and constituent phases. The cooling rates of different atomizing processes are related to the dendrite arm spacings and to the microstructure of the atomized powders. The increased solubility limits and the formation of metastable compounds in splat-cooled alloys are discussed. Consolidation of the powders by hot isostatic compaction, hot extrusion, or hot forging and rolling processes yields billets with properties equivalent to or better than those of the wrought alloys. The application of this powder processing technology to high-performance alloys is reviewed.

  20. Liquid metal thermal-electric converter electrode development

    SciTech Connect

    Martinez, J.I.

    1988-02-01

    This report describes work done in support of distributed receiver technology development. Dish-electric systems are being pursued in an effort to circumvent the need for energy transport by providing for heat-to-electricity energy conversion by individual heat engines at the focal point of parabolic dish concentrators. The Liquid Metal Thermal-Electric Converter is an engine that can convert thermal energy to electricity without the need for moving parts. The report documents the results of contracted work in the development of a long-lifetime, high-performance electrode for LMTEC, including the materials prepared for it. 17 refs., 20 figs., 3 tabs.

  1. Indirect passive cooling system for liquid metal cooled nuclear reactors

    DOEpatents

    Hunsbedt, Anstein; Boardman, Charles E.

    1990-01-01

    A liquid metal cooled nuclear reactor having a passive cooling system for removing residual heat resulting from fuel decay during reactor shutdown. The passive cooling system comprises a plurality of partitions surrounding the reactor vessel in spaced apart relation forming intermediate areas for circulating heat transferring fluid which remove and carry away heat from the reactor vessel. The passive cooling system includes a closed primary fluid circuit through the partitions surrounding the reactor vessel and a partially adjoining secondary open fluid circuit for carrying transferred heat out into the atmosphere.

  2. The stress analysis of a heavy liquid metal pump impeller

    NASA Astrophysics Data System (ADS)

    Ma, X. D.; Li, X. L.; Zhu, Z. Q.; Li, C. J.; Gao, S.

    2016-05-01

    Lead-based coolant reactor is a promising Generation-IV reactor. In the lead-based coolant reactor, the coolant is liquid lead or lead-bismuth eutectic. The main pump in the reactor is a very important device. It supplies force for the coolant circulation. The liquid metal has a very large density which is about ten times of the water. Also, the viscosity of the coolant is small which is about one sixth of the water. When the pump transports heavy liquid, the blade loading is heavy. The large force can cause the failure of the blade when the fatigue stress exceeds the allowable stress. The impeller fraction is a very serious accident which is strictly prohibited in the nuclear reactor. In this paper, the numerical method is used to simulate the flow field of a heavy liquid metal pump. The SST k-w turbulent model is used in the calculation to get a more precise flow structure. The hydraulic force is obtained with the one way fluid solid coupling. The maximum stress in the impeller is analyzed. The stress in the liquid metal pump is compared with that in the water pump. The calculation results show that the maximum stress of the impeller blade increases with increase of flow rate. In the design of the impeller blade thickness, the impeller strength in large operating condition should be considered. The maximum stress of the impeller blade located in the middle and near the hub of the leading edge. In this position, the blade is easy to fracture. The maximum deformation of the impeller firstly increase with increase of flow rate and then decrease with increase of flow rate. The maximum deformation exists in the middle of the leading edge when in small flow rate and in the out radius of the impeller when in large flow rate. Comparing the stress of the impeller when transporting water and LBE, the maximum stress is almost one-tenth of that in the LBE impeller which is the same ratio of the density. The static stress in different medium is proportional to the pressure

  3. Magnesium-Antimony Liquid Metal Battery for Stationary Energy Storage

    SciTech Connect

    Bradwell, DJ; Kim, H; Sirk, AHC; Sadoway, DR

    2012-02-01

    Batteries are an attractive option for grid: scale energy storage applications because of their small footprint and flexible siting. A high-temperature (700 degrees C) magnesium antimony (MgllSb) liquid metal battery comprising a negative electrode of Mg, a molten salt electrolyte (MgCL2-KCl-NaCl), and a positive electrode of Sb is proposed and characterized. Because of the immiscibility of the contiguous salt and metal phases, they stratify by density into three distinct layers. Cells were cycled at rates ranging from 50 to 200 mA/cm(2) and demonstrated up to 69% DC-DC energy efficiency. The self-segregating nature of the battery components and the use Of low-cost materials results in a promising technology for stationary energy storage applications.

  4. PREFACE: 13th International Conference on Liquid and Amorphous Metals

    NASA Astrophysics Data System (ADS)

    Popel, Pjotr; Gelchinskii, Boris; Sidorov, Valeriy; Son, Leonid; Sabirzjanov, Alexandre

    2007-06-01

    The state of the art in the field of liquid and amorphous metals and alloys is regularly updated through two series of complementary international conferences, the LAM (Liquid and Amorphous Metals) and the RQ (Rapidly Quenched Materials). The first series of the conferences started as LM-1 in 1966 at Brookhaven for the basic understanding of liquid metals. The subsequent LM conferences were held in Tokyo (1972) and Bristol (1976). The conference was renewed in Grenoble (1980) as a LAM conference including amorphous metals and continued in Los Angeles (1983), Garmisch-Partenkirchen (1986), Kyoto (1989), Vienna (1992), Chicago (1995), Dortmund (1998), Yokohama (2001) and Metz (2004). The conferences are mainly devoted to liquid and amorphous metals and alloys. However, communications on some non-metallic systems such as semi conductors, quasicrystals etc, were accepted as well. The conference tradition strongly encourages the participation of junior researchers and graduate students. The 13th conference of the LAM series was organized in Ekaterinburg, Russia, by the Institute of Metallurgy of the Ural Branch of the Russian Academy of Sciences (IMet UB RAS) and Ural State Pedagogical University (USPU) and held on 8-13 July 2007 under the chairmanship of Professors Pjotr Popel (USPU) and Boris Gelchinskii (IMet UB RAS). There were 242 active and about 60 guest participants from 20 countries who attended the conference. There were no parallel sessions and all oral reports were separated into three groups: invited talks (40 min), full-scale (25 min) and brief (15 min) oral reports. The program included 10 sessions, ranging from purely theoretical subjects to technological application of molten and amorphous alloys. The following sessions took place: A) Electronic structure and transport, magnetic properties; B) Phase transitions; C) Structure; D) Atomic dynamics and transport; E) Thermodynamics; F) Modelling, simulation; G) Surface and interface; H) Mechanical properties

  5. Metal ion adsorption at the ionic liquid-mica interface.

    PubMed

    McDonald, Samila; Elbourne, Aaron; Warr, Gregory G; Atkin, Rob

    2016-01-14

    Mica has been employed in many studies of ionic liquid (IL) interfaces on account of its atomic smoothness and well defined surface properties. However, until now it has been unclear whether ions dissolved in ILs can compete with the IL cation and adsorb to mica charge sites. In this work amplitude modulated atomic force microscopy (AM-AFM) has been used to probe metal ion adsorption at the interface of mica with propylammonium nitrate (PAN), a room temperature IL. Lithium, sodium, potassium, magnesium and calcium nitrate salts were added to PAN at a concentration of ∼60 mM. Aluminum nitrate was also investigated, but only at 5 mM because its solubility in PAN is much lower. The AM-AFM images obtained when the metal ions were present are strikingly different to that of pure PAN, indicating that the ions compete effectively with the propylammonium cation and adsorb to negatively charged sites on the mica surface despite their much lower concentration. This is a consequence of electrostatic attractions between the mica charge sites and the metal ions being significantly stronger than for the propylammonium cation; compared to the metal ions the propylammonium charged group is relatively constrained sterically. A distinct honeycomb pattern is noted for the PAN + Al(3+) system, less obviously for the divalent ions and not at all for monovalent ions. This difference is attributed to the strength of electrostatic interactions between metal ions and mica charge sites increasing with the ion charge, which means that divalent and (particularly) trivalent ions are located more precisely above the charged sites of the mica lattice. The images obtained allow important distinctions between metal ion adsorption at mica-water and mica-PAN interfaces to be made. PMID:26661934

  6. Metal ion adsorption at the ionic liquid-mica interface.

    PubMed

    McDonald, Samila; Elbourne, Aaron; Warr, Gregory G; Atkin, Rob

    2016-01-14

    Mica has been employed in many studies of ionic liquid (IL) interfaces on account of its atomic smoothness and well defined surface properties. However, until now it has been unclear whether ions dissolved in ILs can compete with the IL cation and adsorb to mica charge sites. In this work amplitude modulated atomic force microscopy (AM-AFM) has been used to probe metal ion adsorption at the interface of mica with propylammonium nitrate (PAN), a room temperature IL. Lithium, sodium, potassium, magnesium and calcium nitrate salts were added to PAN at a concentration of ∼60 mM. Aluminum nitrate was also investigated, but only at 5 mM because its solubility in PAN is much lower. The AM-AFM images obtained when the metal ions were present are strikingly different to that of pure PAN, indicating that the ions compete effectively with the propylammonium cation and adsorb to negatively charged sites on the mica surface despite their much lower concentration. This is a consequence of electrostatic attractions between the mica charge sites and the metal ions being significantly stronger than for the propylammonium cation; compared to the metal ions the propylammonium charged group is relatively constrained sterically. A distinct honeycomb pattern is noted for the PAN + Al(3+) system, less obviously for the divalent ions and not at all for monovalent ions. This difference is attributed to the strength of electrostatic interactions between metal ions and mica charge sites increasing with the ion charge, which means that divalent and (particularly) trivalent ions are located more precisely above the charged sites of the mica lattice. The images obtained allow important distinctions between metal ion adsorption at mica-water and mica-PAN interfaces to be made.

  7. High Temperature Concentrated Solar Power Using Liquid Metal

    NASA Astrophysics Data System (ADS)

    Henry, Asegun

    One of the most attractive ways to try and reduce the cost of concentrated solar power (CSP) is to increase the system efficiency and the biggest loss in the system occurs in the conversion of heat to electricity via heat engine. Heat engines that utilize turbomachinery currently operate near their thermodynamic limitations and thus one of the only ways to improve heat engine efficiency is to increase the turbine inlet temperature. Significant effort is being devoted to the development of supercritical CO2 heat engines, but the most efficient heat engines are combined cycles, which reach efficiencies as high as 60%. However, such heat engines require turbine inlet temperatures ~1300-1500C, which is far beyond what is currently feasible with the state of the art molten salt infrastructure. In working towards the development of a system that can operate in the 1300-1500C temperature range, the most significant challenges lie in the materials and forming functional and reliable components out of new materials. One of the most attractive options from a cost and heat transfer perspective is to use liquid metals, such as tin and aluminum-silicon alloys along with a ceramic based infrastructure. This talk will overview ongoing efforts in the Atomistic Simulation and Energy (ASE) research group at Georgia Tech to develop prototype components such as an efficient high temperature cavity receiver, pumps and valves that can make a liquid metal based CSP infrastructure realizable.

  8. Specific power of liquid-metal-cooled reactors

    SciTech Connect

    Dobranich, D.

    1987-10-01

    Calculations of the core specific power for conceptual space-based liquid-metal-cooled reactors, based on heat transfer considerations, are presented for three different fuel types: (1) pin-type fuel; (2) cermet fuel; and (3) thermionic fuel. The calculations are based on simple models and are intended to provide preliminary comparative results. The specific power is of interest because it is a measure of the core mass required to produce a given amount of power. Potential problems concerning zero-g critical heat flux and loss-of-coolant accidents are also discussed because these concerns may limit the core specific power. Insufficient experimental data exists to accurately determine the critical heat flux of liquid-metal-cooled reactors in space; however, preliminary calculations indicate that it may be a concern. Results also indicate that the specific power of the pin-type fuels can be increased significantly if the gap between the fuel and the clad is eliminated. Cermet reactors offer the highest specific power because of the excellent thermal conductivity of the core matrix material. However, it may not be possible to take fuel advantage of this characteristic when loss-of-coolant accidents are considered in the final core design. The specific power of the thermionic fuels is dependent mainly on the emitter temperature. The small diameter thermionic fuels have specific powers comparable to those of pin-type fuels. 11 refs., 12 figs, 2 tabs.

  9. Liquid metal-to-gas leak-detection instruments. [LMFBR

    SciTech Connect

    Matlin, E.; Witherspoon, J.E.; Johnson, J.L.

    1982-01-01

    It is desirable for liquid-metal-cooled reactors that small liquid metal-to-gas leaks be reliably detected. Testing has been performed on a number of detection systems to evaluate their sensitivity, response time, and performance characteristics. This testing has been scheduled in three phases. The first phase was aimed at screening out the least suitable detectors and optimizing the performance of the most promising. In the second phase, candidates were tested in a 1500 ft/sup 3/ walk-in type enclosure in which leaks were simulated on 24-in. and 3-in. piping. In the third phase of testing, selected type detectors were tested in the 1500-ft/sup 3/ enclosure with Clinch River Breeder Reactor Plant (CRBRP) pipe insulation configurations and detector tubing configuration with cell gas recirculation simulated. Endurance testing of detection equipment was also performed as part of this effort. Test results have been shown that aerosol-type detectors will reliably detect leaks as small as a few grams per hour when sampling pipe insulation annuli.

  10. The Atomic scale structure of liquid metal-electrolyte interfaces

    NASA Astrophysics Data System (ADS)

    Murphy, B. M.; Festersen, S.; Magnussen, O. M.

    2016-07-01

    Electrochemical interfaces between immiscible liquids have lately received renewed interest, both for gaining fundamental insight as well as for applications in nanomaterial synthesis. In this feature article we demonstrate that the atomic scale structure of these previously inaccessible interfaces nowadays can be explored by in situ synchrotron based X-ray scattering techniques. Exemplary studies of a prototypical electrochemical system - a liquid mercury electrode in pure NaCl solution - reveal that the liquid metal is terminated by a well-defined atomic layer. This layering decays on length scales of 0.5 nm into the Hg bulk and displays a potential and temperature dependent behaviour that can be explained by electrocapillary effects and contributions of the electronic charge distribution on the electrode. In similar studies of nanomaterial growth, performed for the electrochemical deposition of PbFBr, a complex nucleation and growth behaviour is found, involving a crystalline precursor layer prior to the 3D crystal growth. Operando X-ray scattering measurements provide detailed data on the processes of nanoscale film formation.

  11. The Atomic scale structure of liquid metal-electrolyte interfaces.

    PubMed

    Murphy, B M; Festersen, S; Magnussen, O M

    2016-08-01

    Electrochemical interfaces between immiscible liquids have lately received renewed interest, both for gaining fundamental insight as well as for applications in nanomaterial synthesis. In this feature article we demonstrate that the atomic scale structure of these previously inaccessible interfaces nowadays can be explored by in situ synchrotron based X-ray scattering techniques. Exemplary studies of a prototypical electrochemical system - a liquid mercury electrode in pure NaCl solution - reveal that the liquid metal is terminated by a well-defined atomic layer. This layering decays on length scales of 0.5 nm into the Hg bulk and displays a potential and temperature dependent behaviour that can be explained by electrocapillary effects and contributions of the electronic charge distribution on the electrode. In similar studies of nanomaterial growth, performed for the electrochemical deposition of PbFBr, a complex nucleation and growth behaviour is found, involving a crystalline precursor layer prior to the 3D crystal growth. Operando X-ray scattering measurements provide detailed data on the processes of nanoscale film formation. PMID:27301317

  12. The Atomic scale structure of liquid metal-electrolyte interfaces.

    PubMed

    Murphy, B M; Festersen, S; Magnussen, O M

    2016-08-01

    Electrochemical interfaces between immiscible liquids have lately received renewed interest, both for gaining fundamental insight as well as for applications in nanomaterial synthesis. In this feature article we demonstrate that the atomic scale structure of these previously inaccessible interfaces nowadays can be explored by in situ synchrotron based X-ray scattering techniques. Exemplary studies of a prototypical electrochemical system - a liquid mercury electrode in pure NaCl solution - reveal that the liquid metal is terminated by a well-defined atomic layer. This layering decays on length scales of 0.5 nm into the Hg bulk and displays a potential and temperature dependent behaviour that can be explained by electrocapillary effects and contributions of the electronic charge distribution on the electrode. In similar studies of nanomaterial growth, performed for the electrochemical deposition of PbFBr, a complex nucleation and growth behaviour is found, involving a crystalline precursor layer prior to the 3D crystal growth. Operando X-ray scattering measurements provide detailed data on the processes of nanoscale film formation.

  13. Liquid metal micro heat pipes for space radiator applications

    NASA Technical Reports Server (NTRS)

    Gerner, F. M.; Henderson, H. T.

    1995-01-01

    Micromachining is a chemical means of etching three-dimensional structures, typically in single-crystalline silicon. These techniques are leading toward what is coming to be referred to as MEMS (micro electro mechanical systems), where in addition to the ordinary two dimensional (planar) microelectronics, it is possible to build three-dimensional micromotors, electrically-actuated microvalves, hydraulic systems, and much more on the same microchip. These techniques become possible because of differential etching rates of various crystallographic planes and materials used for semiconductor microfabrication. The University of Cincinnati group in collaboration with NASA Lewis formed micro heat pipes in silicon by the above techniques. Work is ongoing at a modest level, but several essential bonding and packaging techniques have been recently developed. Currently, we have constructed and filled water/silicon micro heat pipes. Preliminary thermal tests of arrays of 125 micro heat pipes etched in a 1 inch x 1 inch x 250 micron silicon wafer have been completed. These pipes are instrumented with extremely small P-N junctions to measure their effective conductivity and their maximum operating power. A relatively simple one-dimensional model has been developed in order to predict micro heat pipes' operating characteristics. This information can be used to optimize micro heat pipe design with respect to length, hydraulic diameter, and number of pipes. Work is progressing on the fabrication of liquid-metal micro heat pipes. In order to be compatible with liquid metal (sodium or potassium), the inside of the micro heat pipes will be coated with a refractory metal (such as tungsten, molybdenum, or titanium).

  14. Mechanical annealing in the flow of supercooled metallic liquid

    SciTech Connect

    Zhang, Meng; Dai, Lan Hong; Liu, Lin

    2014-08-07

    Flow induced structural evolution in a supercooled metallic liquid Vit106a (Zr{sub 58.5}Cu{sub 15.6}Al{sub 10.3}Ni{sub 12.8}Nb{sub 2.8}, at. %) was investigated via uni-axial compression combined with differential scanning calorimeter (DSC). Compression tests at strain rates covering the transition from Newtonian flow to non-Newtonian flow and at the same strain rate 2 × 10{sup −1} s{sup −1} to different strains were performed at the end of glass transition (T{sub g-end} = 703 K). The relaxation enthalpies measured by DSC indicate that the samples underwent non-Newtonian flow contain more free volume than the thermally annealed sample (703 K, 4 min), while the samples underwent Newtonian flow contain less, namely, the free volume of supercooled metallic liquids increases in non-Newtonian flow, while decreases in Newtonian flow. The oscillated variation of the relaxation enthalpies of the samples deformed at the same strain rate 2 × 10{sup −1} s{sup −1} to different strains confirms that the decrease of free volume was caused by flow stress, i.e., “mechanical annealing.” Micro-hardness tests were also performed to show a similar structural evolution tendency. Based on the obtained results, the stress-temperature scaling in the glass transition of metallic glasses are supported experimentally, as stress plays a role similar to temperature in the creation and annihilation of free volume. In addition, a widening perspective angle on the glass transition of metallic glasses by exploring the 3-dimensional stress-temperature-enthalpy phase diagram is presented. The implications of the observed mechanical annealing effect on the amorphous structure and the work-hardening mechanism of metallic glasses are elucidated based on atomic level stress model.

  15. Transport properties of liquid metal hydrogen under high pressures

    NASA Technical Reports Server (NTRS)

    Brown, R. C.; March, N. H.

    1972-01-01

    A theory is developed for the compressibility and transport properties of liquid metallic hydrogen, near to its melting point and under high pressure. The interionic force law is assumed to be of the screened Coulomb type, because hydrogen has no core electrons. The random phase approximation is used to obtain the structure factor S(k) of the system in terms of the Fourier transform of this force law. The long wavelenth limit of the structure factor S(o) is related to the compressibility, which is much lower than that of alkali metals at their melting points. The diffusion constant at the melting point is obtained in terms of the Debye frequency, using a frequency spectrum analogous with the phonon spectrum of a solid. A similar argument is used to obtain the combined shear and bulk viscosities, but these depend also on S(o). The transport coefficients are found to be about the same size as those of alkali metals at their melting points.

  16. Electron transport across metal/discotic liquid crystal interfaces

    NASA Astrophysics Data System (ADS)

    Boden, N.; Bushby, R. J.; Clements, J.; Movaghar, B.

    1998-03-01

    Electron transport across micron thick films of columnar hexagonal discotic liquid crystal phases homeotropically aligned between metal electrode surfaces has been studied both experimentally and theoretically. These molecules are unique in their combination of charge transport along individual molecular columns with liquidlike self-organization. Typical of organic insulators, a high resistance Ohmic regime is evident at fields of less than 0.05 MV cm-1, due to a low concentration of chemical impurities (n<109cm-3), and a space-charge injection regime at higher fields. Breakdown fields are reasonably high: in hexakis(hexyloxy)triphenylene they reach ˜5 MV cm-1 at room temperature. Our results show that triphenylene-based discotics form an excellent class of highly ordered optically transparent insulators. At high temperatures and high fields the current is injection controlled and exhibits typical tunneling and space charge limited, nonlinear I-V characteristics. Dramatic jumps in injection currents are observed at phase transitions. The change at the crystalline to liquid crystalline phase transition is mainly due to more efficient "wetting" of the electrode surface in the liquid crystalline phase, whilst at the liquid crystalline to isotropic phase transition it arises from the enhancement in the molecular mobility. The concepts of semiconducting gaps, band mobilities, and carrier injection rates are extended to these new materials. The experimental observations are interpreted in a framework which takes into account the important role played by liquidlike dynamics in establishing the microscopic structural order in, what is, otherwise a highly anisotropic and weakly bonded "molecular crystal."

  17. Jumping liquid metal droplet in electrolyte triggered by solid metal particles

    NASA Astrophysics Data System (ADS)

    Tang, Jianbo; Wang, Junjie; Liu, Jing; Zhou, Yuan

    2016-05-01

    We report the electron discharge effect due to point contact between liquid metal and solid metal particles in electrolyte. Adding nickel particles induces drastic hydrogen generating and intermittent jumping of a sub-millimeter EGaIn droplet in NaOH solution. Observations from different orientations disclose that such jumping behavior is triggered by pressurized bubbles under the assistance of interfacial interactions. Hydrogen evolution around particles provides clear evidence that such electric instability originates from the varied electric potential and morphology between the two metallic materials. The point-contact-induced charge concentration significantly enhances the near-surface electric field intensity at the particle tips and thus causes electric breakdown of the electrolyte.

  18. Evaluation of liquid metal embrittlement susceptibility of oxide dispersion strengthened steel MA956

    NASA Astrophysics Data System (ADS)

    Baker, B. W.; Brewer, L. N.

    2014-10-01

    This research examined the susceptibility of MA956 to liquid metal embrittlement using two experimental approaches. In both approaches, historical data on traditional steels was used to determine likely conditions to promote liquid metal embrittlement in lead and lead-bismuth eutectic environments. U-bend specimens of MA956 were found to be immune to liquid metal embrittlement after prolonged exposure to liquid lead. Similarly, slow strain rate testing of MA956 showed immunity to liquid metal embrittlement for both lead and lead-bismuth at temperatures of 328 °C and 150 °C respectively corresponding to the melting temperature of each embrittler individually. These results suggest that the same passive protective oxide layers that limit general corrosion and oxidation also prevent liquid metal embrittlement.

  19. Kinetics of gas-to-liquid and liquid-to-solid transfer of particles in metal-matrix composites

    NASA Technical Reports Server (NTRS)

    Stefanescu, D. M.; Rana, F.; Moitra, A.; Kacar, S.

    1990-01-01

    Analytical models for transfer of particles from gas to liquid and from liquid to solid are introduced. The model for calculation of the pushing/engulfment transition in directionally solidified particulate metal matrix composites, considers process thermodynamics, process kinetics, thermophysical properties and buoyant forces. Based on processing variables (solidification velocity and direction) and on material variables (interface energies, particle size, particle and liquid density, volume fraction of particles and particle/liquid thermal conductivity ratio) four types of behavior were predicted. Also, two numerical models for liquid-to-solid transfer are discussed, as well as the limitations of presently available models.

  20. Gallium-Based Room Temperature Liquid Metals and its Application to Single Channel Two-Liquid Hyperelastic Capacitive Strain Sensors

    NASA Astrophysics Data System (ADS)

    Liu, Shanliangzi

    Gallium-based liquid metals are of interest for a variety of applications including flexible electronics, soft robotics, and biomedical devices. Still, nano- to microscale device fabrication with these materials is challenging because of their strong adhesion to a majority of substrates. This unusual high adhesion is attributed to the formation of a thin oxide shell; however, its role in the adhesion process has not yet been established. In the first part of the thesis, we described a multiscale study aiming at understanding the fundamental mechanisms governing wetting and adhesion of gallium-based liquid metals. In particular, macroscale dynamic contact angle measurements were coupled with Scanning Electron Microscope (SEM) imaging to relate macroscopic drop adhesion to morphology of the liquid metal-surface interface. In addition, room temperature liquid-metal microfluidic devices are also attractive systems for hyperelastic strain sensing. Currently two types of liquid metal-based strain sensors exist for inplane measurements: single-microchannel resistive and two-microchannel capacitive devices. However, with a winding serpentine channel geometry, these sensors typically have a footprint of about a square centimeter, limiting the number of sensors that can be embedded into. In the second part of the thesis, firstly, simulations and an experimental setup consisting of two GaInSn filled tubes submerged within a dielectric liquid bath are used to quantify the effects of the cylindrical electrode geometry including diameter, spacing, and meniscus shape as well as dielectric constant of the insulating liquid and the presence of tubing on the overall system's capacitance. Furthermore, a procedure for fabricating the two-liquid capacitor within a single straight polydiemethylsiloxane channel is developed. Lastly, capacitance and response of this compact device to strain and operational issues arising from complex hydrodynamics near liquid-liquid and liquid

  1. Carbonate-coordinated metal complexes precede the formation of liquid amorphous mineral emulsions of divalent metal carbonates†

    PubMed Central

    Wolf, Stephan E.; Müller, Lars; Barrea, Raul; Kampf, Christopher J.; Leiterer, Jork; Panne, Ulrich; Hoffmann, Thorsten

    2011-01-01

    During the mineralisation of metal carbonates MCO3 (M = Ca, Sr, Ba, Mn, Cd, Pb) liquid-like amorphous intermediates emerge. These intermediates that form via a liquid/liquid phase separation behave like a classical emulsion and are stabilized electrostatically. The occurrence of these intermediates is attributed to the formation of highly hydrated networks whose stability is mainly based on weak interactions and the variability of the metal-containing pre-critical clusters. Their existence and compositional freedom are evidenced by electrospray ionization mass spectrometry (ESI-MS). Liquid intermediates in non-classical crystallisation pathways seem to be more common than assumed. PMID:21218241

  2. Clustomesogens: Liquid Crystalline Hybrid Nanomaterials Containing Functional Metal Nanoclusters.

    PubMed

    Molard, Yann

    2016-08-16

    Inorganic phosphorescent octahedral metal nanoclusters fill the gap between metal complexes and nanoparticles. They are finite groups of metal atoms linked by metal-metal bonds, with an exact composition and structure at the nanometer scale. As their phosphorescence internal quantum efficiency can approach 100%, they represent a very attractive class of molecular building blocks to design hybrid nanomaterials dedicated to light energy conversion, optoelectronic, display, lighting, or theragnostic applications. They are obtained as AnM6X(i)8X(a)6 ternary salt powders (A = alkali cation, M = Mo, Re, W, X(i): halogen inner ligand, X(a) = halogen apical ligand) by high temperature solid state synthesis (750-1200 °C). However, their ceramic-like behavior has largely restricted their use as functional components in the past. Since these last two decades, several groups, including ours, started to tackle the challenge of integrating them in easy-to-process materials. Within this context, we have extensively explored the nanocluster ternary salt specificities to develop a new class of self-organized hybrid organic-inorganic nanomaterials known as clustomesogens. These materials, combine the specific properties of nanoclusters (magnetic, electronic, luminescence) with the anisotropy-related properties of liquid crystals (LCs). This Account covers the research and development of clustomesogens starting from the design concepts and synthesis to their introduction in functional devices. We developed three strategies to build such hybrid super- or supramolecules. In the covalent approach, we capitalized on the apical ligand-metal bond iono-covalent character to graft tailor-made organic LC promoters on the {M6X(i)8}(n+) nanocluster cores. The supramolecular approach relies on the host-guest complexation of the ternary cluster salt alkali cations with functional crown ether macrocycles. We showed that the hybrid LC behavior depends on the macrocycles structural features

  3. Liquid-metal magnetohydrodynamic system evaluation. [coal-fired designs

    NASA Technical Reports Server (NTRS)

    Holman, R. R.; Lippert, T. E.

    1976-01-01

    The present study emphasizes a direct coal-fired design using a bubbly two-component flow of sodium and argon in the MHD generator and a Rankine steam-bottoming plant. Two basic cycles were studied, corresponding to argon temperatures of 922 and 1089 K at the duct inlet. The MHD duct system consisted of multiple ducts arranged in clusters and separated by iron magnet pole pieces. The ducts, each with an output of about 100 MW, were parallel to the flow, but were connected in series electrically to provide a higher MHD voltage. With channel efficiencies of 80%, a pump efficiency of 90%, and a 45% efficient steam-bottoming plant, the overall efficiency of the 1089 K liquid-metal MHD power plant was 43%.

  4. Reliability and Maintainability Data for Liquid Metal Cooling Systems

    SciTech Connect

    Cadwallader, Lee Charles

    2015-05-01

    One of the coolants of interest for future fusion breeding blankets is lead-lithium. As a liquid metal it offers the advantages of high temperature operation for good station efficiency, low pressure, and moderate flow rate. This coolant is also under examination for use in test blanket modules to be used in the ITER international project. To perform reliability, availability, maintainability and inspectability (RAMI) assessment as well as probabilistic safety assessment (PSA) of lead-lithium cooling systems, component failure rate data are needed to quantify the system models. RAMI assessment also requires repair time data and inspection time data. This paper presents a new survey of the data sets that are available at present to support RAMI and PSA quantification. Recommendations are given for the best data values to use when quantifying system models.

  5. High-resolution mass spectrometer for liquid metal ion sources

    SciTech Connect

    Wortmann, Martin; Ludwig, Arne; Reuter, Dirk; Wieck, Andreas D.; Meijer, Jan

    2013-09-15

    Recently, a mass spectrometer for liquid metal ion sources (LMIS) has been built and set into operation. This device uses an E×B-filter as mass dispersive element and provides sufficient resolution to analyse the emission of clusters from LMIS to much higher mass ranges (>2000 amu) than commercially available mass filters for focused ion beam systems. It has also been shown that for small masses the composition of clusters from different isotopes can be resolved. Furthermore, a rather high fluence of monodisperse clusters in the range of 10{sup 6}–10{sup 7} clusters/s can be achieved with this setup. This makes it a promising tool for the preparation of mass selected clusters. In this contribution, theoretical considerations as well as technical details and the results of first measurements are presented.

  6. High-resolution mass spectrometer for liquid metal ion sources.

    PubMed

    Wortmann, Martin; Ludwig, Arne; Meijer, Jan; Reuter, Dirk; Wieck, Andreas D

    2013-09-01

    Recently, a mass spectrometer for liquid metal ion sources (LMIS) has been built and set into operation. This device uses an E × B-filter as mass dispersive element and provides sufficient resolution to analyse the emission of clusters from LMIS to much higher mass ranges (>2000 amu) than commercially available mass filters for focused ion beam systems. It has also been shown that for small masses the composition of clusters from different isotopes can be resolved. Furthermore, a rather high fluence of monodisperse clusters in the range of 10(6)-10(7) clusters/s can be achieved with this setup. This makes it a promising tool for the preparation of mass selected clusters. In this contribution, theoretical considerations as well as technical details and the results of first measurements are presented.

  7. Cleavage crystallography of liquid metal embrittled aluminum alloys

    NASA Technical Reports Server (NTRS)

    Reynolds, A. P.; Stoner, G. E.

    1991-01-01

    The crystallography of liquid metal-induced transgranular cleavage in six aluminum alloys having a variety of microstructures has been determined via Laue X-ray back reflection. The cleavage crystallography was independent of alloy microstructure, and the cleavage plane was 100-plane oriented in all cases. It was further determined that the cleavage crystallography was not influenced by alloy texture. Examination of the fracture surface indicated that there was not a unique direction of crack propagation. In addition, the existence of 100-plane cleavage on alloy 2024 fracture surfaces was inferred by comparison of secondary cleavage crack intersection geometry on the 2024 surfaces with the geometry of secondary cleavage crack intersections on the test alloys.

  8. Method of shielding a liquid-metal-cooled reactor

    DOEpatents

    Sayre, Robert K.

    1978-01-01

    The primary heat transport system of a nuclear reactor -- particularly for a liquid-metal-cooled fast-breeder reactor -- is shielded and protected from leakage by establishing and maintaining a bed of a powdered oxide closely and completely surrounding all components thereof by passing a gas upwardly therethrough at such a rate as to slightly expand the bed to the extent that the components of the system are able to expand without damage and yet the particles of the bed remain close enough so that the bed acts as a guard vessel for the system. Preferably the gas contains 1 to 10% oxygen and the gas is passed upwardly through the bed at such a rate that the lower portion of the bed is a fixed bed while the upper portion is a fluidized bed, the line of demarcation therebetween being high enough that the fixed bed portion of the bed serves as guard vessel for the system.

  9. Capture of liquid hydrogen boiloff with metal hydride absorbers

    NASA Technical Reports Server (NTRS)

    Rosso, M. J.; Golben, P. M.

    1984-01-01

    A procedure which uses metal hydrides to capture some of this low pressure (,1 psig) hydrogen for subsequent reliquefaction is described. Of the five normally occurring sources of boil-off vapor the stream associated with the off-loading of liquid tankers during dewar refill was identified as the most cost effective and readily recoverable. The design, fabrication and testing of a proof-of-concept capture device, operating at a rate that is commensurate with the evolution of vapor by the target stream, is described. Liberation of the captured hydrogen gas at pressure .15 psig at normal temperatures (typical liquefier compressor suction pressure) are also demonstrated. A payback time of less than three years is projected.

  10. Testing of Liquid Metal Components for Nuclear Surface Power Systems

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.; Godfroy, Thomas J.; Pearson, J. Boise

    2010-01-01

    The Early Flight Fission Test Facility (EFF-TF) was established by the Marshall Space Flight Center (MSFC) to provide a capability for performing hardware-directed activities to support multiple in-space nuclear reactor concepts by using a non-nuclear test methodology. This includes fabrication and testing at both the module/component level and near prototypic reactor configurations. The EFF-TF is currently supporting an effort to develop an affordable fission surface power (AFSP) system that could be deployed on the Lunar surface. The AFSP system is presently based on a pumped liquid metal-cooled (Sodium-Potassium eutectic, NaK-78) reactor design. This design was derived from the only fission system that the United States has deployed for space operation, the Systems for Nuclear Auxiliary Power (SNAP) 10A reactor, which was launched in 1965. Two prototypical components recently tested at MSFC were a pair of Stirling power conversion units that would be used in a reactor system to convert heat to electricity, and an annular linear induction pump (ALIP) that uses travelling electromagnetic fields to pump the liquid metal coolant through the reactor loop. First ever tests were conducted at MSFC to determine baseline performance of a pair of 1 kW Stirling convertors using NaK as the hot side working fluid. A special test rig was designed and constructed and testing was conducted inside a vacuum chamber at MSFC. This test rig delivered pumped NaK for the hot end temperature to the Stirlings and water as the working fluid on the cold end temperature. These test were conducted through a hot end temperature range between 400 to 550C in increments of 50 C and a cold end temperature range from 30 to 70 C in 20 C increments. Piston amplitudes were varied from 6 to 1 1mm in .5 mm increments. A maximum of 2240 Watts electric was produced at the design point of 550 hot end, 40 C cold end with a piston amplitude of 10.5mm. This power level was reached at a gross thermal

  11. Review of experimental investigations of liquid-metal heat transfer

    NASA Technical Reports Server (NTRS)

    Lubarsky, Bernard; Kaufman, Samuel J

    1956-01-01

    Experimental data of various investigators of liquid-metal heat-transfer characteristics were reevaluated using as consistent assumptions and methods as possible and then compared with each other and with theoretical results. The reevaluated data for both local fully developed and average Nusselt numbers in the turbulent flow region were found still to have considerable spread, with the bulk of the data being lower than predicted by existing analysis. An equation based on empirical grounds which represents most of the fully developed heat-transfer data is nu = 0.625 pe(0.4) where nu represents the Nusselt number and pe the Peclet number. The theoretical prediction of the heat transfer in the entrance region was found to give lower values, in most cases, than those found in the experimental work.

  12. Liquid Metal Pump Technologies for Nuclear Surface Power

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.

    2007-01-01

    Multiple liquid metal pump options are reviewed for the purpose of determining the technologies that are best suited for inclusion in a nuclear reactor thermal simulator intended to rest prototypical space nuclear surface power system components. Conduction, induction and thermoelectric electromagnetic pumps are evaluated based on their performance characteristics and the technical issues associated with incorporation into a reactor system. A thermoelectric electromagnetic pump is selected as the best option for use in NASA-MSFC's Fission Surface Power-Primary Test Circuit reactor simulator based on its relative simplicity, low power supply mass penalty, flight heritage, and the promise of increased pump efficiency over those earlier pump designs through the use of skutterudite thermoelectric elements.

  13. Numerical simulation of turbulent forced convection in liquid metals

    NASA Astrophysics Data System (ADS)

    Vodret, S.; Vitale Di Maio, D.; Caruso, G.

    2014-11-01

    In the frame of the future generation of nuclear reactors, liquid metals are foreseen to be used as a primary coolant. Liquid metals are characterized by a very low Prandtl number due to their very high heat diffusivity. As such, they do not meet the so-called Reynolds analogy which assumes a complete similarity between the momentum and the thermal boundary layers via the use of the turbulent Prandtl number. Particularly, in the case of industrial fluid-dynamic calculations where a resolved computation near walls could be extremely time consuming and could need very large computational resources, the use of the classical wall function approach could lead to an inaccurate description of the temperature profile close to the wall. The first aim of the present study is to investigate the ability of a well- established commercial code (ANSYS FLUENT v.14) to deal with this issue, validating a suitable expression for the turbulent Prandtl number. Moreover, a thermal wall-function developed at Universite Catholique de Louvain has been implemented in FLUENT and validated, overcoming the limits of the solver to define it directly. Both the resolved and unresolved approaches have been carried out for a channel flow case and assessed against available direct numerical and large eddy simulations. A comparison between the numerically evaluated Nusselt number and the main correlations available in the literature has been also carried out. Finally, an application of the proposed methodology to a typical sub-channel case has been performed, comparing the results with literature correlations for tube banks.

  14. A reconfigurable liquid metal antenna driven by electrochemically controlled capillarity

    SciTech Connect

    Wang, M.; Adams, J. J.; Trlica, C.; Khan, M. R.; Dickey, M. D.

    2015-05-21

    We describe a new electrochemical method for reversible, pump-free control of liquid eutectic gallium and indium (EGaIn) in a capillary. Electrochemical deposition (or removal) of a surface oxide on the EGaIn significantly lowers (or increases) its interfacial tension as a means to induce the liquid metal in (or out) of the capillary. A fabricated prototype demonstrates this method in a reconfigurable antenna application in which EGaIn forms the radiating element. By inducing a change in the physical length of the EGaIn, the operating frequency of the antenna tunes over a large bandwidth. This purely electrochemical mechanism uses low, DC voltages to tune the antenna continuously and reversibly between 0.66 GHz and 3.4 GHz resulting in a 5:1 tuning range. Gain and radiation pattern measurements agree with electromagnetic simulations of the device, and its measured radiation efficiency varies from 41% to 70% over its tuning range.

  15. Growth of metal oxide nanowires from supercooled liquid nanodroplets.

    SciTech Connect

    Kim, M. H.; Lee, B.; Lee, S.; Larson, C.; Balik, J. M.; Yavuz, C. T.; Seifert, S.; Vajda, S.; Winans, R. E.; Moskovits, M.; Stucky, G. D.; Wodtke, A. M.; Univ. of California at Santa Barbara; Yale Univ.

    2009-12-01

    Nanometer-sized liquid droplets formed at temperatures below the bulk melting point become supercooled as they grow through Ostwald ripening or coalescence and can be exploited to grow nanowires without any catalyst. We used this simple approach to synthesize a number of highly crystalline metal oxide nanowires in a chemical or physical vapor deposition apparatus. Examples of nanowires made in this way include VO{sub 2}, V{sub 2}O{sub 5}, RuO{sub 2}, MoO{sub 2}, MoO{sub 3}, and Fe{sub 3}O{sub 4}, some of which have not been previously reported. Direct evidence of this new mechanism of nanowire growth is found from in situ 2-dimensional GISAXS (grazing incidence small angle X-ray scattering) measurements of VO{sub 2} nanowire growth, which provides quantitative information on the shapes and sizes of growing nanowires as well as direct evidence of the presence of supercooled liquid droplets. We observe dramatic changes in nanowire growth by varying the choice of substrate, reflecting the influence of wetting forces on the supercooled nanodroplet shape and mobility as well as substrate-nanowire lattice matching on the definition of nanowire orientation. Surfaces with defects can also be used to pattern the growth of the nanowires. The simplicity of this synthesis concept suggests it may be rather general in its application.

  16. Electric current induced flow of liquid metals: Mechanism and substrate-surface effects

    SciTech Connect

    Kumar, P.; Howarth, J.; Dutta, I.

    2014-01-28

    Long range, continuous flow of liquid metals occurs upon application of an electric current. Here, we report experimental results elucidating the mechanism of current-induced liquid metal flow, and its dependence on substrate surface condition. It is shown that the observed flow is diffusion-controlled, with the flow-rate depending linearly on applied current density, indicating that it is driven by electromigration. The effective charge number for liquid electromigration, Z*, of several pure metals, such as Al, Bi, Ga, Sn, and Pb, were deduced from the experimental results and were found to be close to the elemental valency. With the exception of liquid Pb, Z* for all liquid metals tested in this study were positive, indicating that: (i) electron wind contributes much less to Z* in liquid metals than in solids, and (ii) with a few exceptions, liquid metals generally flow in the direction of the electric current. On smooth substrates which are wetted well by the liquid metal, flow occurs in a thin, continuous stream. On rough surfaces which are poorly wetted, on the other hand, discrete beads of liquid form, with mass transport between adjacent beads occurring by surface diffusion on the substrate. A rationale for the role of substrate roughness in fostering this observed transition in flow mechanism is presented.

  17. Experimental Partitioning of As and SB Among Metal, Troilite, Schreibersite, Barringerite, and Metallic Liquid

    NASA Astrophysics Data System (ADS)

    Jones, J. H.; Casanova, I.

    1993-07-01

    We have performed a series of experiments to evaluate the behaviors of As and Sb in metallic systems. Because of the reputed chalcophile nature of these elements, we wrongly anticipated that they would follow S and that, compared to the Fe-X systems [1], (solid metal/liquid metal) partition coefficients would be considerably lower in S-bearing systems. Experimental and Analytical: Experiments were performed in sealed silica tubes as in [2]. Starting materials were high-purity metals, natural pyrite, and natural stibnite. Charges were doped either with As or Sb. Experiments were held at either 950 degrees C for six days or 1250 degrees C for three days. Typical experimental assemblages consisted either of taenite and coexisting Fe-Ni-S-X liquid (1250 degrees and 950 degrees C) or an assemblage of troilite, schreibersite, and Fe-Ni-S-P-X liquid (950 degrees C). The schreibersite-bearing, As-doped charge also contained barringerite (Fe,Ni)2P. Charges were mounted in epoxy, polished, and analyzed using a Cameca SX-50 electron microprobe and standard techniques. Results: Phases appeared homogeneous. Our results, along with partition coefficients inferred for the S-free system, are given in Table 1. Table 1 appears here in the hard copy. Discussion: Our results indicate that As behaves as a siderophile element at low temperatures, very analogous to Au. While the siderophility of Sb increases with decreasing temperature, it remains incompatible in solid metal. In this regard Sb is unique. Both As and Sb are very incompatible in troilite. Arsenic is weakly incompatible in schreibersite and strongly compatible in barringerite. Nickel shows no preference for either phosphide. Nickel partition coefficients for metal and schreibersite are similar to those measured previously [3]. On a lnD vs. ln(1-2 alpha X(S)) diagram [4], the data for Sb and As subparallel each other, indicating similar dependencies on S, despite their very different partition coefficients. Arsenic behaves

  18. Space- and time-resolved resistive measurements of liquid metal wall thickness

    NASA Astrophysics Data System (ADS)

    Mirhoseini, S. M. H.; Volpe, F. A.

    2016-11-01

    In a fusion reactor internally coated with liquid metal, it will be important to diagnose the thickness of the liquid at various locations in the vessel, as a function of time, and possibly respond to counteract undesired bulging or depletion. The electrical conductance between electrodes immersed in the liquid metal can be used as a simple proxy for the local thickness. Here a matrix of electrodes is shown to provide spatially and temporally resolved measurements of liquid metal thickness in the absence of plasma. First a theory is developed for m × n electrodes, and then it is experimentally demonstrated for 3 × 1 electrodes, as the liquid stands still or is agitated by means of a shaker. The experiments were carried out with Galinstan, but are easily extended to lithium or other liquid metals.

  19. Diffusion in liquid metal systems. [information on electrical resistivity and thermal conductivity

    NASA Technical Reports Server (NTRS)

    Ukanwa, A. O.

    1975-01-01

    Physical properties of twenty liquid metals are reported; some of the data on such liquid metal properties as density, electrical resistivity, thermal conductivity, and heat capacity are summarized in graphical form. Data on laboratory handling and safety procedure are summarized for each metal; heat-transfer-correlations for liquid metals under various conditions of laminar and turbulent flow are included. Where sufficient data were available, temperature equations of properties were obtained by the method of least-squares fit. All values of properties given are valid in the given liquid phase ranges only. Additional tabular data on some 40 metals are reported in the appendix. Included is a brief description of experiments that were performed to investigate diffusion in liquid indium-gallium systems.

  20. Single channel double-duct liquid metal electrical generator using a magnetohydrodynamic device

    DOEpatents

    Haaland, C.M.; Deeds, W.E.

    1999-07-13

    A single channel double-duct liquid metal electrical generator using a magnetohydrodynamic (MHD) device. The single channel device provides useful output AC electric energy. The generator includes a two-cylinder linear-piston engine which drives liquid metal in a single channel looped around one side of the MHD device to form a double-duct contra-flowing liquid metal MHD generator. A flow conduit network and drive mechanism are provided for moving liquid metal with an oscillating flow through a static magnetic field to produce useful AC electric energy at practical voltages and currents. Variable stroke is obtained by controlling the quantity of liquid metal in the channel. High efficiency is obtained over a wide range of frequency and power output. 5 figs.

  1. Single channel double-duct liquid metal electrical generator using a magnetohydrodynamic device

    DOEpatents

    Haaland, Carsten M.; Deeds, W. Edward

    1999-01-01

    A single channel double-duct liquid metal electrical generator using a magnetohydrodynamic (MHD) device. The single channel device provides useful output AC electric energy. The generator includes a two-cylinder linear-piston engine which drives liquid metal in a single channel looped around one side of the MHD device to form a double-duct contra-flowing liquid metal MHD generator. A flow conduit network and drive mechanism are provided for moving liquid metal with an oscillating flow through a static magnetic field to produce useful AC electric energy at practical voltages and currents. Variable stroke is obtained by controlling the quantity of liquid metal in the channel. High efficiency is obtained over a wide range of frequency and power output.

  2. Simplified thermochemistry of oxygen in lithium and sodium for liquid metal cooling systems

    NASA Technical Reports Server (NTRS)

    Tower, L. K.

    1972-01-01

    Plots of oxygen chemical potential against composition of lithium-oxygen solutions and sodium-oxygen solutions for a range of temperature were constructed. For each liquid metal two such plots were prepared. For one plot ideal solution behavior was assumed. For the other plot, existing solubility limit data for oxygen in the liquid metal were used to determine a first-order term for departure from ideality. The use of the plots in evaluating the oxygen gettering capability of refractory metals in liquid metal cooling systems is illustrated by a simple example involving lithium, oxygen, and hafnium.

  3. Corrosion-resistant fuel cladding allow for liquid metal fast breeder reactors

    DOEpatents

    Brehm, Jr., William F.; Colburn, Richard P.

    1982-01-01

    An aluminide coating for a fuel cladding tube for LMFBRs (liquid metal fast breeder reactors) such as those using liquid sodium as a heat transfer agent. The coating comprises a mixture of nickel-aluminum intermetallic phases and presents good corrosion resistance to liquid sodium at temperatures up to 700.degree. C. while additionally presenting a barrier to outward diffusion of .sup.54 Mn.

  4. Fragment structure from vapor explosions during the impact of molten metal droplets into a liquid pool

    NASA Astrophysics Data System (ADS)

    Kouraytem, Nadia; Li, Er Qiang; Vakarelski, Ivan Uriev; Thoroddsen, Sigurdur

    2015-11-01

    High-speed video imaging is used in order to look at the impact of a molten metal drop falling into a liquid pool. The interaction regimes are three: film boiling, nucleate boiling or vapor explosion. Following the vapor explosion, the metal fragments and different textures are observed. It was seen that, using a tin alloy, a porous structure results whereas using a distinctive eutectic metal, Field's metal, micro beads are formed. Different parameters such as the metal type, molten metal temperature, pool surface tension and pool boiling temperature have been altered in order to assess the role they play on the explosion dynamics and the molten metal's by product.

  5. Metal Chlorides in Ionic Liquid Solvents Convert Sugars to 5-Hydroxymethylfurfural

    SciTech Connect

    Zhao, Haibo; Holladay, John E.; Brown, Heather M.; Zhang, Z. Conrad

    2007-06-15

    Sugars were converted to hydroxymethylfurfural (HMF) at high yield in ionic liquids without the addition of Bronsted acids. Very small amount of certain metal halides significantly reduced the fructose dehydration barrier in ionic liquids producing HMF at high yields. Most remarkably, glucose, a common sugar molecule, was selectively converted to HMF in good yield in ionic liquids containing a small amount of CrCl2. Thus CrCl2 is unique among metal chlorides tested for its effectiveness in both isomerizing glucose as well as dehydrating fructose. Only negligble amount of levulinic acid was formed in the reactions. The catalytic activity of metal chlorides for sugar conversion in ionic liquids is perhaps related to hydroxyl group of the sugar forming metal complexes with the unsaturated metal center.

  6. On-Chip Production of Size-Controllable Liquid Metal Microdroplets Using Acoustic Waves.

    PubMed

    Tang, Shi-Yang; Ayan, Bugra; Nama, Nitesh; Bian, Yusheng; Lata, James P; Guo, Xiasheng; Huang, Tony Jun

    2016-07-01

    Micro- to nanosized droplets of liquid metals, such as eutectic gallium indium (EGaIn) and Galinstan, have been used for developing a variety of applications in flexible electronics, sensors, catalysts, and drug delivery systems. Currently used methods for producing micro- to nanosized droplets of such liquid metals possess one or several drawbacks, including the lack in ability to control the size of the produced droplets, mass produce droplets, produce smaller droplet sizes, and miniaturize the system. Here, a novel method is introduced using acoustic wave-induced forces for on-chip production of EGaIn liquid-metal microdroplets with controllable size. The size distribution of liquid metal microdroplets is tuned by controlling the interfacial tension of the metal using either electrochemistry or electrocapillarity in the acoustic field. The developed platform is then used for heavy metal ion detection utilizing the produced liquid metal microdroplets as the working electrode. It is also demonstrated that a significant enhancement of the sensing performance is achieved by introducing acoustic streaming during the electrochemical experiments. The demonstrated technique can be used for developing liquid-metal-based systems for a wide range of applications. PMID:27309129

  7. On-Chip Production of Size-Controllable Liquid Metal Microdroplets Using Acoustic Waves.

    PubMed

    Tang, Shi-Yang; Ayan, Bugra; Nama, Nitesh; Bian, Yusheng; Lata, James P; Guo, Xiasheng; Huang, Tony Jun

    2016-07-01

    Micro- to nanosized droplets of liquid metals, such as eutectic gallium indium (EGaIn) and Galinstan, have been used for developing a variety of applications in flexible electronics, sensors, catalysts, and drug delivery systems. Currently used methods for producing micro- to nanosized droplets of such liquid metals possess one or several drawbacks, including the lack in ability to control the size of the produced droplets, mass produce droplets, produce smaller droplet sizes, and miniaturize the system. Here, a novel method is introduced using acoustic wave-induced forces for on-chip production of EGaIn liquid-metal microdroplets with controllable size. The size distribution of liquid metal microdroplets is tuned by controlling the interfacial tension of the metal using either electrochemistry or electrocapillarity in the acoustic field. The developed platform is then used for heavy metal ion detection utilizing the produced liquid metal microdroplets as the working electrode. It is also demonstrated that a significant enhancement of the sensing performance is achieved by introducing acoustic streaming during the electrochemical experiments. The demonstrated technique can be used for developing liquid-metal-based systems for a wide range of applications.

  8. Alloys for a liquid metal fast breeder reactor

    DOEpatents

    Rowcliffe, Arthur F.; Bleiberg, Melvin L.; Diamond, Sidney; Bajaj, Ram

    1979-01-01

    An essentially gamma-prime precipitation-hardened iron-chromium-nickel alloy has been designed with emphasis on minimum nickel and chromium contents to reduce the swelling tendencies of these alloys when used in liquid metal fast breeder reactors. The precipitation-hardening components have been designed for phase stability and such residual elements as silicon and boron, also have been selected to minimize swelling. Using the properties of these alloys in one design would result in an increased breeding ratio over 20% cold worked stainless steel, a reference material, of 1.239 to 1.310 and a reduced doubling time from 15.8 to 11.4 years. The gross stoichiometry of the alloying composition comprises from about 0.04% to about 0.06% carbon, from about 0.05% to about 1.0% silicon, up to about 0.1% zirconium, up to about 0.5% vanadium, from about 24% to about 31% nickel, from 8% to about 11% chromium, from about 1.7% to about 3.5% titanium, from about 1.0% to about 1.8% aluminum, from about 0.9% to about 3.7% molybdenum, from about 0.04% to about 0.8% boron, and the balance iron with incidental impurities.

  9. Liquid-vapor phase diagram of metals using EAM potential

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Chandrani

    2013-02-01

    Pair-wise additive potentials are not adequate to describe the properties of metallic systems since many body effects are completely ignored in that approximation. In this regard, the embedded atom method is more appropriate because, in addition to the pair interaction, the total energy includes an embedding energy which is the energy required to add an impurity atom to the host electron fluid. Thus EAM takes into account the many body effects to some extent. We use the Cai and Ye's EAM potential to predict the liquid vapor phase diagram and critical constants of Aluminum and Copper within a perturbation theory approach. In this method, free energy of a fluid molecule, trapped in a cage formed by its nearest neighbors, is expanded about a hard sphere reference system. The first order correction term is calculated in terms of the zero temperature isotherm of the solid obtained using the EAM potential. Higher order correction terms are added to account for the deviation of the behavior of the real fluid from the reference hard sphere fluid.

  10. An investigation of corrosion in liquid-metal heat pipes

    SciTech Connect

    Adkins, D.R.; Rawlinson, K.S.; Andraka, C.E.; Showalter, S.K.; Moreno, J.B.; Moss, T.A.; Cordiero, P.G.

    1998-08-01

    Research is underway to develop a 75-kW heat pipe to transfer solar energy from the focus of a parabolic dish concentrator to the heater tubes of a Stirling engine. The high flux levels and high total power level encountered in this application have made it necessary to use a high-performance wick structure with fibers on the order of 4 to 8 microns in diameter. This fine wick structure is highly susceptible to corrosion damage and plugging, as dissolved contaminants plate out on the evaporator surface. Normal operation of the heat pipe also tends to concentrate contaminants in localized areas of the evaporator surface where heat fluxes are the highest. Sandia National Laboratories is conducting a systematic study to identify procedures that reduce corrosion and contamination problems in liquid-metal heat pipes. A series of heat pipes are being tested to explore different options for cleaning heat-pipe systems. Models are being developed to help understand the overall importance of operating parameters on the life of heat-pipe systems. In this paper, the authors present their efforts to reduce corrosion damage.

  11. Liquid metal thermoelectric converter (LMTEC) for solar applications

    SciTech Connect

    Martinez, J.I.

    1985-01-01

    An overview is given of the research and development plan for the Liquid Metal Thermoelectric Converter (LMTEC) being undertaken by Sandia Laboratories under the Solar Thermal Technologies program of DOE. Sandia initiated work in this area less than a year ago and has pursued the work as a specific subtask starting in FY 1985. As with any new project, a significant part of the initial effort has been spent on reviewing the current technology in thermo-electric converters including Thermally Regenerative Electrochemical Systems (TRES), fuel cells, thermionic devices, magnetohydrodynamics, and other modes of direct thermal-to-electric conversion. Consequently, no formal research results are included in this paper and the presentation is intended more to indicate those areas in which further research and development efforts could be expended to prove of positive impact on the solar application of LMTEC. The principal objective of this task is to design, engineer, and develop a LMTEC suitable for use in solar distributed receiver applications. Since the thermal requirements for the LMTEC are in the temperature range of parabolic dishes, the engineering development effort will concentrate on a device that can be mounted at the focal point of a dish and preferably incorporated into the receiver. Due to a technology review, the LMTEC most likely will be based on the current Sodium Heat Engine (SHE) concept. Our main effort will consist of optimizing the concept for solar applications and conducting the necessary engineering development to produce a 20 to 50 kWe device.

  12. Elevator mode convection in liquid metal blankets for fusion reactors

    NASA Astrophysics Data System (ADS)

    Zikanov, Oleg; Liu, Li

    2015-11-01

    The work is motivated by the design of liquid-metal blankets for nuclear fusion reactors. Mixed convection in a downward flow in a vertical duct with strong contant-rate heating of one wall (the Grashof number up to 1012) and strong transverse magnetic field (the Hartmann number up to 104) is considered. It is found that in an infinitely long duct the flow is dominated by exponentially growing elevator modes having the form of a combination of ascending and descending jets. An analytical solution approximating the growth rate of the modes is derived. Analogous flows in finite-length pipes and ducts are analyzed using the high-resolution numerical simulations. The results of the recent experiments are reproduced and explained. It is found that the flow evolves in cycles consisting of periods of exponential growth and breakdowns of the jets. The resulting high-amplitude fluctuations of temperature is a feature potentially dangerous for operation of a reactor blanket. Financial support was provided by the US NSF (Grant CBET 1232851).

  13. Variations of the Lifshitz-van der Waals force between metals immersed in liquids.

    PubMed

    Esquivel-Sirvent, R

    2010-05-21

    We present a theoretical calculation of the Lifshitz-van der Waals force between two metallic slabs embedded in a fluid, taking into account the change of the Drude parameters of the metals when in contact with liquids of different index of refraction. For the three liquids considered in this work, water, CCl(3)F and CBr(3)F the change in the Drude parameters of the metal imply a difference of up to 15% in the determination of the force at short separations. These variations in the force are larger for liquids with a higher index of refraction.

  14. Frequency-Switchable Metamaterial Absorber Injecting Eutectic Gallium-Indium (EGaIn) Liquid Metal Alloy

    PubMed Central

    Ling, Kenyu; Kim, Hyung Ki; Yoo, Minyeong; Lim, Sungjoon

    2015-01-01

    In this study, we demonstrated a new class of frequency-switchable metamaterial absorber in the X-band. Eutectic gallium-indium (EGaIn), a liquid metal alloy, was injected in a microfluidic channel engraved on polymethyl methacrylate (PMMA) to achieve frequency switching. Numerical simulation and experimental results are presented for two cases: when the microfluidic channels are empty, and when they are filled with liquid metal. To evaluate the performance of the fabricated absorber prototype, it is tested with a rectangular waveguide. The resonant frequency was successfully switched from 10.96 GHz to 10.61 GHz after injecting liquid metal while maintaining absorptivity higher than 98%. PMID:26561815

  15. Design study for a liquid metal slip ring solar array orientation mechanism

    NASA Technical Reports Server (NTRS)

    Clark, R. B.

    1972-01-01

    The design of a single axis orientation mechanism for solar arrays on high power synchronous satellites is studied primarily with respect to providing 116 liquid metal slip rings for reduced friction and improved electrical characteristics. Designs and tradeoff studies for the slip rings and other components are presented. An assembly containing 33 slip rings of three design approaches was designed, fabricated, and vacuum tested to 30 amperes and 30,000 volts. Containment of the liquid metal gallium in large diameter slip rings was difficult. A design approach is presented which is expected to provide improved retention of the liquid metal.

  16. Review of the highlights of X-ray studies of liquid metal surfaces

    SciTech Connect

    Pershan, P. S.

    2014-12-14

    X-ray studies of the interface between liquid metals and their coexisting vapor are reviewed. After a brief discussion of the few elemental liquid metals for which the surface Debye-Waller effect is sufficiently weak to allow measurement, this paper will go on to discuss the various types of surface phenomena that have been observed for liquid metal alloys. These include surface adsorption, surface freezing, surface aggregation of nm size atomic clusters, and surface chemistry that leads to new 3D crystalline phases.

  17. Investigation of Liquid Metal Embrittlement of Materials for use in Fusion Reactors

    NASA Astrophysics Data System (ADS)

    Kennedy, Daniel; Jaworski, Michael

    2014-10-01

    Liquid metals can provide a continually replenished material for the first wall and extraction blankets of fusion reactors. However, research has shown that solid metal surfaces will experience embrittlement when exposed to liquid metals under stress. Therefore, it is important to understand the changes in structural strength of the solid metal materials and test different surface treatments that can limit embrittlement. Research was conducted to design and build an apparatus for exposing solid metal samples to liquid metal under high stress and temperature. The apparatus design, results of tensile testing, and surface imaging of fractured samples will be presented. This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internships Program (SULI).

  18. Uphill transport of rare-earth metals through a highly stable supported liquid membrane based on an ionic liquid.

    PubMed

    Kubota, Fukiko; Shimobori, Yousuke; Koyanagi, Yusuke; Shimojo, Kojiro; Kamiya, Noriho; Goto, Masahiro

    2010-01-01

    We have developed a highly stable supported liquid membrane based on ionic liquids (ILs) for the separation of rare-earth metals, employing N,N-dioctyldiglycol amic acid as a mobile carrier. The quantitative transport of Y and Eu through the membrane was successfully attained, and separation from metal impurities, Zn, was efficiently accomplished. A membrane stable enough for long-term operation was constructible from imidazolium-based ILs having a longer alkyl chain, such as octyl or dodecyl groups in an imidazolium cation.

  19. Nanofabrication of highly ordered, tunable metallic mesostructures via quasi-hard-templating of lyotropic liquid crystals

    PubMed Central

    Zhang, Xinyi; Lu, Wei; Dai, Jiyan; Bourgeois, Laure; Yao, Jianfeng; Wang, Huanting; Friend, James R.; Zhao, Dongyuan; MacFarlane, Douglas R.

    2014-01-01

    The synthesis of metal frameworks perforated with nanotunnels is a challenge because metals have high surface energies that favor low surface area structures; traditional liquid-crystal templating techniques cannot achieve the synthetic control required. We report a synthetic strategy to fabricate metal nanomaterials with highly ordered, tunable mesostructures in confined systems based on a new quasi-hard-templating liquid-crystals mechanism. The resulting platinum nanowires exhibit long range two-dimensional hexagonally ordered mesopore structures. In addition, single crystalline hexagonal mesoporous platinum nanowires with dominant {110} facets have been synthesized. Finally, we demonstrate that the mesostructures of metal nanomaterials can be tuned from hexagonal to lamellar mesostructures. PMID:25502015

  20. Carbonate-coordinated metal complexes precede the formation of liquid amorphous mineral emulsions of divalent metal carbonates

    NASA Astrophysics Data System (ADS)

    Wolf, Stephan E.; Müller, Lars; Barrea, Raul; Kampf, Christopher J.; Leiterer, Jork; Panne, Ulrich; Hoffmann, Thorsten; Emmerling, Franziska; Tremel, Wolfgang

    2011-03-01

    During the mineralisation of metal carbonates MCO3 (M = Ca, Sr, Ba, Mn, Cd, Pb) liquid-like amorphous intermediates emerge. These intermediates that form via a liquid/liquid phase separation behave like a classical emulsion and are stabilized electrostatically. The occurrence of these intermediates is attributed to the formation of highly hydrated networks whose stability is mainly based on weak interactions and the variability of the metal-containing pre-critical clusters. Their existence and compositional freedom are evidenced by electrospray ionization mass spectrometry (ESI-MS). Liquid intermediates in non-classical crystallisation pathways seem to be more common than assumed.During the mineralisation of metal carbonates MCO3 (M = Ca, Sr, Ba, Mn, Cd, Pb) liquid-like amorphous intermediates emerge. These intermediates that form via a liquid/liquid phase separation behave like a classical emulsion and are stabilized electrostatically. The occurrence of these intermediates is attributed to the formation of highly hydrated networks whose stability is mainly based on weak interactions and the variability of the metal-containing pre-critical clusters. Their existence and compositional freedom are evidenced by electrospray ionization mass spectrometry (ESI-MS). Liquid intermediates in non-classical crystallisation pathways seem to be more common than assumed. Electronic supplementary information (ESI) available: (S1 and S5) TEM at higher magnifications and of crystallizations conducted at pH = 6.0, 9.0 and 11.3; (S2) sketch of a spreading liquid particle on a TEM grid; (S3) wide-angle scattering of BaCO3 and CdCO3; (S4 and S6-S9) ESI-MS spectra of a solution of carbon dioxide and of bicarbonates of Sr, Ba, Pb, Mn and Cd. See DOI: 10.1039/c0nr00761g

  1. Natural circulation in a liquid metal one-dimensional loop

    NASA Astrophysics Data System (ADS)

    Tarantino, M.; De Grandis, S.; Benamati, G.; Oriolo, F.

    2008-06-01

    A wide use of pure lead, as well as its alloys (such as lead-bismuth, lead-lithium), is foreseen in several nuclear-related fields: it is studied as coolant in critical and sub-critical nuclear reactors, as spallation target for neutron generation in several applications and for tritium generation in fusion systems. In this framework, a new facility named NAtural CIrculation Experiment (NACIE), has been designed at ENEA-Brasimone Research Centre. NACIE is a rectangular loop, made by stainless steel pipes. It consists mainly of a cold and hot leg and an expansion tank installed on the top of the loop. A fuel bundle simulator, made by three electrical heaters placed in a triangular lattice, is located in the lower part of the cold leg, while a tube in tube heat exchanger is installed in the upper part of the hot leg. The adopted secondary fluid is THT oil, while the foreseen primary fluid for the tests is lead-bismuth in eutectic composition (LBE). The aim of the facility is to carry out experimental tests of natural circulation and collect data on the heat transfer coefficient (HTC) for heavy liquid metal flowing through rod bundles. The paper is focused on the preliminary estimation of the LBE flow rate along the loop. An analytical methodology has been applied, solving the continuity, momentum and energy transport equations under appropriate hypothesis. Moreover numerical simulations have been performed. The FLUENT 6.2 CFD code has been utilized for the numerical simulations. The main results carried out from the pre-tests simulations are illustrated in the paper, and a comparison with the theoretical estimations is done.

  2. Improved simulations of heat transfer in liquid metal flows.

    SciTech Connect

    Tzanos, C.

    2011-04-01

    In liquid-metal flows, the predictions of the Nusselt number (heat transfer) by Reynolds-averaged Navier-Stokes models of turbulence that use the assumption of a constant turbulent Prandtl number can be significantly off. Heat transfer analyses were performed with a number of turbulence models for flows in a triangular rod bundle and in a pipe, and model predictions were compared with experimental data. Emphasis was placed on the low Reynolds (low-Re) number k-{var_epsilon} model that resolves the boundary layer and does not use 'logarithmic wall functions.' The high Reynolds (high-Re) number k-{var_epsilon} model underpredicts the Nusselt number up to 30%, while the low-Re number model overpredicts it up to 34%. For high Peclet number values, the low-Re number model provides better predictions than the high-Re number model. For Peclet numbers higher than 1500, the predictions of the Reynolds stress model (RSM) are in very good agreement with experimental measurements, but for lower Peclet number values its predictions are significantly off. A relationship was developed that expresses the turbulent Prandtl number as a function of the ratio of the turbulent viscosity to the molecular viscosity. With this modified turbulent Prandtl number, for the flow in the rod bundle the predictions of the low-Re number model are well within the spread of the experimental measurements. For pipe flow, the model predictions are not as sensitive to the correction of the turbulent Prandtl number as they are in the case of the flow in a bundle. The modified low-Re number model underpredicts the limited experimental data by 4%.

  3. Testing of Liquid Metal Components for Nuclear Surface Power Systems

    NASA Technical Reports Server (NTRS)

    Polzin, K. A.; Pearson, J. B.; Godfroy, T. J.; Schoenfeld, M.; Webster, K.; Briggs, M. H.; Geng, S. M.; Adkins, H. E.; Werner, J. E.

    2010-01-01

    The capability to perform testing at both the module/component level and in near prototypic reactor configurations using a non-nuclear test methodology allowed for evaluation of two components critical to the development of a potential nuclear fission power system for the lunar surface. A pair of 1 kW Stirling power convertors, similar to the type that would be used in a reactor system to convert heat to electricity, were integrated into a reactor simulator system to determine their performance using pumped NaK as the hot side working fluid. The performance in the pumped-NaK system met or exceed the baseline performance measurements where the converters were electrically heated. At the maximum hot-side temperature of 550 C the maximum output power was 2375 watts. A specially-designed test apparatus was fabricated and used to quantify the performance of an annular linear induction pump that is similar to the type that could be used to circulate liquid metal through the core of a space reactor system. The errors on the measurements were generally much smaller than the magnitude of the measurements, permitting accurate performance evaluation over a wide range of operating conditions. The pump produced flow rates spanning roughly 0.16 to 5.7 l/s (2.5 to 90 GPM), and delta p levels from less than 1 kPa to 90 kPa (greater than 0.145 psi to roughly 13 psi). At the nominal FSP system operating temperature of 525 C the maximum efficiency was just over 4%.

  4. Modification of an oxygen bomb calorimeter to measure enthalpies of reaction of liquid metals.

    PubMed

    Carling, R W

    1978-10-01

    Modification of a commercially available oxygen bomb calorimeter is described. This modification permits direct determination of the enthalpies of reaction of liquid metals that have melting points below about 310 K. PMID:18698983

  5. Model of liquid-metal splashing in the cathode spot of a vacuum arc discharge

    NASA Astrophysics Data System (ADS)

    Gashkov, M. A.; Zubarev, N. M.; Zubareva, O. V.; Mesyats, G. A.; Uimanov, I. V.

    2016-04-01

    The formation of microjets is studied during the extrusion of a melted metal by the plasma pressure from craters formed on a cathode in a burning vacuum arc. An analytic model of liquid-metal splashing that includes two stages is proposed. At the first stage, the liquid motion has the axial symmetry and a liquid-metal wall surrounding the crater is formed. At the second stage, the axial symmetry is broken due to the development of the Plateau-Rayleigh instability in the upper part of the wall. The wall breakup process is shown to have a threshold. The minimal plasma pressure and the minimal electric current flowing through the crater required for obtaining the liquid-metal splashing regime are found. The basic spatial and temporal characteristics of the jet formation process are found using the analytic model.

  6. The mechanism of liquid metal jet formation in the cathode spot of vacuum arc discharge

    NASA Astrophysics Data System (ADS)

    Gashkov, M. A.; Zubarev, N. M.; Mesyats, G. A.; Uimanov, I. V.

    2016-08-01

    We have theoretically studied the dynamics of molten metal during crater formation in the cathode spot of vacuum arc discharge. At the initial stage, a liquid-metal ridge is formed around the crater. This process has been numerically simulated in the framework of the two-dimensional axisymmetric heat and mass transfer problem in the approximation of viscous incompressible liquid. At a more developed stage, the motion of liquid metal loses axial symmetry, which corresponds to a tendency toward jet formation. The development of azimuthal instabilities of the ridge is analyzed in terms of dispersion relations for surface waves. It is shown that maximum increments correspond to instability of the Rayleigh-Plateau type. Estimations of the time of formation of liquid metal jets and their probable number are obtained.

  7. RARE-EARTH METAL FISSION PRODUCTS FROM LIQUID U-Bi

    DOEpatents

    Wiswall, R.H.

    1960-05-10

    Fission product metals can be removed from solution in liquid bismuth without removal of an appreciable quantity of uranium by contacting the liquid metal solution with fused halides, as for example, the halides of sodium, potassium, and lithium and by adding to the contacted phases a quantity of a halide which is unstable relative to the halides of the fission products, a specific unstable halide being MgCl/sub 3/.

  8. The t-matrix resistivity of liquid rare earth metals using pseudopotential

    SciTech Connect

    Bhatia, Kamaldeep G.; Bhatt, N. K.; Vyas, P. R.; Gohel, V. B.

    2015-06-24

    Present theoretical study of liquid metal resistivity of some trivalent (La,Ce,Gd) and divalent (Eu,Yb) rare earth metals using pseudopotential has been carried out employing Ziman’s weak scattering and transition matrix (t-matrix) approaches. Our computed results of liquid metal resistivity using t-matrix approach are better than resistivity computed using Ziman’s approach and are also in excellent agreement with experimental results and other theoretical findings. The present study confirms that for f-shell metals pseudopotential must be determined uniquely and t-matrix approach is more physical in comparison with Ziman’s nearly free electron approach. The present pseudopotential accounts s-p-d hybridization properly. Such success encourages us to study remaining liquid state properties of these metals.

  9. Development of a fast thermal response microfluidic system using liquid metal

    NASA Astrophysics Data System (ADS)

    Gao, Meng; Gui, Lin

    2016-07-01

    Room temperature liquid metal gallium alloy has been widely used in many micro-electromechanical systems applications, such as on-chip electrical microheaters, micro temperature sensors, micro pumps and so on. Injecting liquid metal into microchannels can provide a simple, rapid, low-cost but efficient way to integrate these elements in microfluidic chips with high accuracy. The liquid metal-filled microstructures can be designed in any shape and easily integrated into microfluidic chips. In this paper, an on-chip liquid metal-based thermal microfluidic system is proposed for quick temperature control at the microscale. The micro system utilizes just one microfluidic chip as a basic working platform, which has liquid metal-based on-chip heaters, temperature sensors and electroosmotic flow pumps. Under the comprehensive control of these elements, the micro system can quickly change the temperature of a target fluid in the microfluidic chip. These liquid metal-based on-chip elements are very helpful for the fabrication and miniaturization of the microfluidic chip. In this paper, deionized water is used to test the temperature control performance of the thermal microfluidic system. According to the experimental results, the micro system can efficiently control the temperature of water ranging from 28 °C to 90 °C. The thermal microfluidic system has great potential for use in many microfluidic applications, such as on-chip polymerase chain reaction, temperature gradient focusing, protein crystallization and chemical synthesis.

  10. Experimental Investigation on Liquid Metal Flow Distribution in Insulating Manifold under Uniform Magnetic Field

    NASA Astrophysics Data System (ADS)

    Miura, Masato; Ueki, Yoshitaka; Yokomine, Takehiko; Kunugi, Tomoaki

    2012-11-01

    Magnetohydrodynamics (MHD) problem which is caused by interaction between electrical conducting fluid flow and the magnetic field is one of the biggest problem in the liquid metal blanket of the fusion reactor. In the liquid metal blanket concept, it is necessary to distribute liquid metal flows uniformly in the manifold because imbalance of flow rates should affect the heat transfer performance directly, which leads to safety problem. While the manifold is insulated electrically as well as the flow duct, the 3D-MHD effect on the flowing liquid metal in the manifold is more apparent than that in straight duct. With reference to the flow distribution in this concept, the liquid metal flow in the electrical insulating manifold under the uniform transverse magnetic field is investigated experimentally. In this study, GaInSn is selected as working fluid. The experimental system includes the electrical magnet and the manifold test section which is made of acrylic resin for perfectly electrical insulation. The liquid metal flows in a non-symmetric 180°-turn with manifold, which consists of one upward channel and two downward channels. The flow rates in each channel are measured by electromagnetic flow meters for several combinations Reynolds number and Hartman number. The effects of magnetic field on the uniformity of flow distribution are cleared.

  11. Binding in pair potentials of liquid simple metals from nonlocality in electronic kinetic energy

    NASA Technical Reports Server (NTRS)

    Perrot, F.; March, N. H.

    1990-01-01

    The paper presents an explicit expression for the pair potential in liquid simple metals from low-order density-gradient theory when the superposition of single-center displaced charges is employed. Numerical results are presented for the gradient expansion pair interaction in liquid Na and Be. The low-order density-gradient equation for the pair potential is presented.

  12. Sidewall containment of liquid metal with horizontal alternating magnetic fields

    DOEpatents

    Praeg, Walter F.

    1995-01-01

    An apparatus for confining molten metal with a horizontal alternating magnetic field. In particular, this invention employs a magnet that can produce a horizontal alternating magnetic field to confine a molten metal at the edges of parallel horizontal rollers as a solid metal sheet is cast by counter-rotation of the rollers.

  13. Sidewall containment of liquid metal with horizontal alternating magnetic fields

    DOEpatents

    Pareg, Walter F.

    1990-01-01

    An apparatus for confining molten metal with a horizontal alternating magnetic field. In particular, this invention employs a magnet that can produce a horizontal alternating magnetic field to confine a molten metal at the edges of parallel horizontal rollers as a solid metal sheet is cast by counter-rotation of the rollers.

  14. The effect of oxygen as a light element in metallic liquids on partitioning behavior

    NASA Astrophysics Data System (ADS)

    Chabot, Nancy L.; Wollack, E. Alex; Humayun, Munir; Shank, Ellen M.

    2015-04-01

    Oxygen has been considered a potentially important light element in metallic liquids during a range of planetary processes, yet the influence of O in a metallic melt on element partitioning behavior is largely unknown. To investigate the effect of O in such systems, we conducted experiments in the Fe-S-O system, doped with 25 trace elements, which produced two immiscible metallic liquids. Our results indicate that the presence of O in the metallic liquid produces a distinctive chemical signature for W and Ga in particular. Tungsten shows an affinity for O in the metallic liquid and partitions more strongly into the metallic melt in the presence of O. The partitioning of Ga is relatively constant despite the presence of O, which is in contrast to the majority of the other siderophile elements in the study. Our experiments from 1400 to 1600 °C show no significant effect from temperature on the partitioning behavior of any trace elements over this limited temperature range. This distinctive chemical signature due to the presence of O in the metallic liquid has potential implications for modeling core formation, evaluating isotopic signatures produced by core crystallization, and interpreting chemical assemblages observed in meteorites.

  15. Sidewall containment of liquid metal with vertical alternating magnetic fields

    DOEpatents

    Lari, R.J.; Praeg, W.F.; Turner, L.R.; Battles, J.E.; Hull, J.R.; Rote, D.M.

    1990-12-04

    An apparatus is disclosed for containing molten metal using a magnet producing vertical alternating magnetic field positioned adjacent the area in which the molten metal is to be confined. This invention can be adapted particularly to the casting of metal between counter-rotating rollers with the vertical alternating magnetic field used to confine the molten metal at the edges of the rollers. Alternately, the vertical alternating magnetic field can be used as a flow regulator in casting molten metal from an opening in a channel. 9 figs.

  16. Sidewall containment of liquid metal with vertical alternating magnetic fields

    DOEpatents

    Lari, R.J.; Praeg, W.F.; Turner, L.R.; Battles, J.E.; Hull, J.R.; Rote, D.M.

    1988-06-17

    An apparatus for containing molten metal using a magnet producing vertical alternating magnetic field positioned adjacent to the area in which the molten metal is to be confined. This invention can be adapted particularly to the casting of metal between counter-rotating rollers with the vertical alternating magnetic field used to confine the molten metal at the edges of the rollers. Alternately, the vertical alternating magnetic field can be used as a flow regulator in casting molten metal from an opening in a channel. 8 figs.

  17. Sidewall containment of liquid metal with vertical alternating magnetic fields

    DOEpatents

    Lari, Robert J.; Praeg, Walter F.; Turner, Larry R.; Battles, James E.; Hull, John R.; Rote, Donald M.

    1990-01-01

    An apparatus for containing molten metal using a magnet producing vertical alternating magnetic field positioned adjacent the area in which the molten metal is to be confined. This invention can be adapted particularly to the casting of metal between counter-rotating rollers with the vertical alternating magnetic field used to confine the molten metal at the edges of the rollers. Alternately, the vertical alternating magnetic field can be used as a flow regulator in casting molten metal from an opening in a channel.

  18. Biomedical Implementation of Liquid Metal Ink as Drawable ECG Electrode and Skin Circuit

    PubMed Central

    Yu, Yang; Zhang, Jie; Liu, Jing

    2013-01-01

    Background Conventional ways of making bio-electrodes are generally complicated, expensive and unconformable. Here we describe for the first time the method of applying Ga-based liquid metal ink as drawable electrocardiogram (ECG) electrodes. Such material owns unique merits in both liquid phase conformability and high electrical conductivity, which provides flexible ways for making electrical circuits on skin surface and a prospective substitution of conventional rigid printed circuit boards (PCBs). Methods Fundamental measurements of impedance and polarization voltage of the liquid metal ink were carried out to evaluate its basic electrical properties. Conceptual experiments were performed to draw the alloy as bio-electrodes to acquire ECG signals from both rabbit and human via a wireless module developed on the mobile phone. Further, a typical electrical circuit was drawn in the palm with the ink to demonstrate its potential of implementing more sophisticated skin circuits. Results With an oxide concentration of 0.34%, the resistivity of the liquid metal ink was measured as 44.1 µΩ·cm with quite low reactance in the form of straight line. Its peak polarization voltage with the physiological saline was detected as −0.73 V. The quality of ECG wave detected from the liquid metal electrodes was found as good as that of conventional electrodes, from both rabbit and human experiments. In addition, the circuit drawn with the liquid metal ink in the palm also runs efficiently. When the loop was switched on, all the light emitting diodes (LEDs) were lit and emitted colorful lights. Conclusions The liquid metal ink promises unique printable electrical properties as both bio-electrodes and electrical wires. The implemented ECG measurement on biological surface and the successfully run skin circuit demonstrated the conformability and attachment of the liquid metal. The present method is expected to innovate future physiological measurement and biological circuit

  19. Thermophysical properties of simple liquid metals: A brief review of theory

    NASA Technical Reports Server (NTRS)

    Stroud, David

    1993-01-01

    In this paper, we review the current theory of the thermophysical properties of simple liquid metals. The emphasis is on thermodynamic properties, but we also briefly discuss the nonequilibrium properties of liquid metals. We begin by defining a 'simple liquid metal' as one in which the valence electrons interact only weakly with the ionic cores, so that the interaction can be treated by perturbation theory. We then write down the equilibrium Hamiltonian of a liquid metal as a sum of five terms: the bare ion-ion interaction, the electron-electron interaction, the bare electron-ion interaction, and the kinetic energies of electrons and ions. Since the electron-ion interaction can be treated by perturbation, the electronic part contributes in two ways to the Helmholtz free energy: it gives a density-dependent term which is independent of the arrangement of ions, and it acts to screen the ion-ion interaction, giving rise to effective ion-ion pair potentials which are density-dependent, in general. After sketching the form of a typical pair potential, we briefly enumerate some methods for calculating the ionic distribution function and hence the Helmholtz free energy of the liquid: monte Carlo simulations, molecular dynamics simulations, and thermodynamic perturbation theory. The final result is a general expression for the Helmholtz free energy of the liquid metal. It can be used to calculate a wide range of thermodynamic properties of simple metal liquids, which we enumerate. They include not only a range of thermodynamic coefficients of both metals and alloys, but also many aspects of the phase diagram, including freezing curves of pure elements and phase diagrams of liquid alloys (including liquidus and solidus curves). We briefly mention some key discoveries resulting from previous applications of this method, and point out that the same methods work for other materials not normally considered to be liquid metals (such as colloidal suspensions, in which the

  20. Appearance of "fragile" Fermi liquids in finite-width Mott insulators sandwiched between metallic leads.

    PubMed

    Zenia, H; Freericks, J K; Krishnamurthy, H R; Pruschke, Th

    2009-09-11

    Using inhomogeneous dynamical mean-field theory, we show that the normal-metal proximity effect could force any finite number of Mott-insulating "barrier" planes sandwiched between semi-infinite metallic leads to become "fragile" Fermi liquids. They are fully Fermi-liquid-like at T=0, leading to a restoration of lattice periodicity at zero frequency, with a well-defined Fermi surface, and perfect (ballistic) conductivity. However, the Fermi-liquid character can rapidly disappear at finite omega, V, T, disorder, or magnetism, all of which restore the expected quantum tunneling regime, leading to fascinating possibilities for nonlinear response in devices.

  1. Enhanced coupling of optical energy during liquid-confined metal ablation

    SciTech Connect

    Kang, Hyun Wook; Welch, Ashley J.

    2015-10-21

    Liquid-confined laser ablation was investigated with various metals of indium, aluminum, and nickel. Ablation threshold and rate were characterized in terms of surface deformation, transient acoustic responses, and plasma emissions. The surface condition affected the degree of ablation dynamics due to variations in reflectance. The liquid confinement yielded up to an order of larger ablation crater along with stronger acoustic transients than dry ablation. Enhanced ablation performance resulted possibly from effective coupling of optical energy at the interface during explosive vaporization, plasma confinement, and cavitation. The deposition of a liquid layer can induce more efficient ablation for laser metal processing.

  2. Quantum spin liquids and the metal-insulator transition in doped semiconductors.

    PubMed

    Potter, Andrew C; Barkeshli, Maissam; McGreevy, John; Senthil, T

    2012-08-17

    We describe a new possible route to the metal-insulator transition in doped semiconductors such as Si:P or Si:B. We explore the possibility that the loss of metallic transport occurs through Mott localization of electrons into a quantum spin liquid state with diffusive charge neutral "spinon" excitations. Such a quantum spin liquid state can appear as an intermediate phase between the metal and the Anderson-Mott insulator. An immediate testable consequence is the presence of metallic thermal conductivity at low temperature in the electrical insulator near the metal-insulator transition. Further, we show that though the transition is second order, the zero temperature residual electrical conductivity will jump as the transition is approached from the metallic side. However, the electrical conductivity will have a nonmonotonic temperature dependence that may complicate the extrapolation to zero temperature. Signatures in other experiments and some comparisons with existing data are made. PMID:23006401

  3. The Numerical Simulation of Liquid-Vapor Stratified Flow in Horizontal Metal-Foam Tubes.

    PubMed

    Wang, Jingxuan; Wang, Yueshe; Chen, Zhengwei; Chen, Kaituo; Li, Bing

    2015-04-01

    In this paper, a boiling stratified flow model in a metal-foam tube is proposed. First, based on Branuer non-equilibrium gas-liquid interface model, a force balance on the gas-liquid interface in metal-foam is calculated. The shape of the interface of upper gas phase and lower liquid phase in metal foam tube is obtained. As for the lower liquid phase, the energy conservation equations of liquid and metal foam are formulated, which account for porosity and fiber diameter of foam on the basis of non-local thermal equilibrium model (NTEM), respectively. Therefore, a profile of temperature difference between liquid and metal foam can be obtained. For the upper gas phase, an empirical correlation developed by other researchers is utilized to obtain temperature difference between gas phase and solid wall. In addition, the variation of the Reynolds number with increasing mass quality along the flow direction is acquired. Ultimately, an average circumference heat transfer coefficient is calculated. The results of circumference heat transfer coefficient agree well with available experimental data, showing the prediction of the proposed stratified flow model is feasible. The reason resulting in discrepancies between the prediction and experiment data is also illustrated. PMID:26353555

  4. Liquid-metal pin-fin pressure drop by correlation in cross flow

    SciTech Connect

    Wang, Zhibi; Kuzay, T.M.; Assoufid, L.

    1994-08-01

    The pin-fin configuration is widely used as a heat transfer enhancement method in high-heat-flux applications. Recently, the pin-fin design with liquid-metal coolant was also applied to synchrotron-radiation beamline devices. This paper investigates the pressure drop in a pin-post design beamline mirror with liquid gallium as the coolant. Because the pin-post configuration is a relatively new concept, information in literature about pin-post mirrors or crystals is rare, and information about the pressure drop in pin-post mirrors with liquid metal as the coolant is even more sparse. Due to this the authors considered the cross flow in cylinder-array geometry, which is very similar to that of the pin-post, to examine the pressure drop correlation with liquid metals over pin fins. The cross flow of fluid with various fluid characteristics or properties through a tube bank was studied so that the results can be scaled to the pin-fin geometry with liquid metal as the coolant. Study lead to two major variables to influence the pressure drop: fluid properties, viscosity and density, and the relative length of the posts. Correlation of the pressure drop between long and short posts and the prediction of the pressure drop of liquid metal in the pin-post mirror and comparison with an existing experiment are addressed.

  5. Conductor of high electrical current at high temperature in oxygen and liquid metal environment

    DOEpatents

    Powell, IV, Adam Clayton; Pati, Soobhankar; Derezinski, Stephen Joseph; Lau, Garrett; Pal, Uday B.; Guan, Xiaofei; Gopalan, Srikanth

    2016-01-12

    In one aspect, the present invention is directed to apparatuses for and methods of conducting electrical current in an oxygen and liquid metal environment. In another aspect, the invention relates to methods for production of metals from their oxides comprising providing a cathode in electrical contact with a molten electrolyte, providing a liquid metal anode separated from the cathode and the molten electrolyte by a solid oxygen ion conducting membrane, providing a current collector at the anode, and establishing a potential between the cathode and the anode.

  6. Transient behaviour of deposition of liquid metal droplets on a solid substrate

    NASA Astrophysics Data System (ADS)

    Chapuis, J.; Romero, E.; Soulié, F.; Bordreuil, C.; Fras, G.

    2016-10-01

    This paper investigates the mechanisms that contribute to the spreading of liquid metal macro-drop deposited during Stationary Pulsed Gas Metal Arc Welding on an initially cold solid workpiece. Surface tension and inertial effects take an important part in the behaviour of the liquid metal macro-drop, but in this configuration the influence of energetic effects can also be significant. The experimental results are discussed in the light of dimensional analysis in order to appreciate the influence of the process parameters and the physical mechanisms involved on the spreading of a macro-drop. A law is established to model forced non-isothermal spreading.

  7. Method and apparatus for regenerating cold traps within liquid-metal systems

    DOEpatents

    McKee, Jr., John M.

    1976-01-01

    Oxide and hydride impurities of a liquid metal such as sodium are removed from a cold trap by heating to a temperature at which the metal hydroxide is stable in a molten state. The partial pressure of hydrogen within the system is measured to determine if excess hydride or oxide is present. Excess hydride is removed by venting hydrogen gas while excess oxide can be converted to molten hydroxide through the addition of hydrogen. The resulting, molten hydroxide is drained from the trap which is then returned to service at cold trap temperatures within the liquid-metal system.

  8. Recovery and Extraction of Heavy Metal Ions Using Ionic Liquid as Green Solvent

    NASA Astrophysics Data System (ADS)

    Kumano, Masami; Yabutani, Tomoki; Motonaka, Junko; Mishima, Yuji

    Ionic liquids are expected to replace conventional organic solvents in organic synthesis, solvent extraction and electrochemistry due to their unique characters such as low volatility, high stability and so on. In this work, N,N,-diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis(trifluoromethansulfonyl)imide was used as an alternative solvent to extract heavy metal ions. As the extracting conditions, the additional effect of 8-hydroxyquinoline (8-HQ) as metal chelating agent into ionic liquids, shaking time and volume ratio were investigated. As extraction efficiency depended on 8-HQ concentration significantly, in order to extract high concentrated metal ions the solubility of 8-HQ into ionic liquid was tested. N,N,-diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis(trifluoromethansulfonyl)imide had good solubility of 8-HQ. Consequently, 5 μmol of copper, zinc, cadmium and manganese could be completely recovered with 100 μl of ionic liquid.

  9. Fabrication methods and applications of microstructured gallium based liquid metal alloys

    NASA Astrophysics Data System (ADS)

    Khondoker, M. A. H.; Sameoto, D.

    2016-09-01

    This review contains a comparative study of reported fabrication techniques of gallium based liquid metal alloys embedded in elastomers such as polydimethylsiloxane or other rubbers as well as the primary challenges associated with their use. The eutectic gallium–indium binary alloy (EGaIn) and gallium–indium–tin ternary alloy (galinstan) are the most common non-toxic liquid metals in use today. Due to their deformability, non-toxicity and superior electrical conductivity, these alloys have become very popular among researchers for flexible and reconfigurable electronics applications. All the available manufacturing techniques have been grouped into four major classes. Among them, casting by needle injection is the most widely used technique as it is capable of producing features as small as 150 nm width by high-pressure infiltration. One particular fabrication challenge with gallium based liquid metals is that an oxide skin is rapidly formed on the entire exposed surface. This oxide skin increases wettability on many surfaces, which is excellent for keeping patterned metal in position, but is a drawback in applications like reconfigurable circuits, where the position of liquid metal needs to be altered and controlled accurately. The major challenges involved in many applications of liquid metal alloys have also been discussed thoroughly in this article.

  10. Fabrication methods and applications of microstructured gallium based liquid metal alloys

    NASA Astrophysics Data System (ADS)

    Khondoker, M. A. H.; Sameoto, D.

    2016-09-01

    This review contains a comparative study of reported fabrication techniques of gallium based liquid metal alloys embedded in elastomers such as polydimethylsiloxane or other rubbers as well as the primary challenges associated with their use. The eutectic gallium-indium binary alloy (EGaIn) and gallium-indium-tin ternary alloy (galinstan) are the most common non-toxic liquid metals in use today. Due to their deformability, non-toxicity and superior electrical conductivity, these alloys have become very popular among researchers for flexible and reconfigurable electronics applications. All the available manufacturing techniques have been grouped into four major classes. Among them, casting by needle injection is the most widely used technique as it is capable of producing features as small as 150 nm width by high-pressure infiltration. One particular fabrication challenge with gallium based liquid metals is that an oxide skin is rapidly formed on the entire exposed surface. This oxide skin increases wettability on many surfaces, which is excellent for keeping patterned metal in position, but is a drawback in applications like reconfigurable circuits, where the position of liquid metal needs to be altered and controlled accurately. The major challenges involved in many applications of liquid metal alloys have also been discussed thoroughly in this article.

  11. Thermodynamic scaling of glassy dynamics and dynamic heterogeneities in metallic glass-forming liquid

    NASA Astrophysics Data System (ADS)

    Hu, Yuan-Chao; Shang, Bao-Shuang; Guan, Peng-Fei; Yang, Yong; Bai, Hai-Yang; Wang, Wei-Hua

    2016-09-01

    A ternary metallic glass-forming liquid is found to be not strongly correlating thermodynamically, but its average dynamics, dynamic heterogeneities including the high order dynamic correlation length, and static structure are still well described by thermodynamic scaling with the same scaling exponent γ. This may indicate that the metallic liquid could be treated as a single-parameter liquid. As an intrinsic material constant stemming from the fundamental interatomic interactions, γ is theoretically predicted from the thermodynamic fluctuations of the potential energy and the virial. Although γ is conventionally understood merely from the repulsive part of the inter-particle potentials, the strong correlation between γ and the Grüneisen parameter up to the accuracy of the Dulong-Petit approximation demonstrates the important roles of anharmonicity and attractive force of the interatomic potential in governing glass transition of metallic glassformers. These findings may shed light on how to understand metallic glass formation from the fundamental interatomic interactions.

  12. Calculation of the surface tension of liquid metals using a one-component-plasma reference system

    NASA Technical Reports Server (NTRS)

    Zeng, X. C.; Stroud, D.

    1987-01-01

    The one-component-plasma (OCP) model is used as a reference system instead of the traditional hard-sphere fluid to calculate the liquid-vapor interfacial surface tension of liquid metals within the density functional formalism. The calculated surface tensions of the alkali metals are in excellent agreement with experiment. For the polyvalent metal Al, the result obtained is larger than experimental measurements. It is concluded that the OCP system is not suitable to describe the liquid-vapor phase transition in simple metals which have a nominal plasma parameter larger than the usual freezing value of about 178. The calculated interfacial widths in all cases are narrower than the expected experimental values.

  13. Thermodynamic scaling of glassy dynamics and dynamic heterogeneities in metallic glass-forming liquid.

    PubMed

    Hu, Yuan-Chao; Shang, Bao-Shuang; Guan, Peng-Fei; Yang, Yong; Bai, Hai-Yang; Wang, Wei-Hua

    2016-09-14

    A ternary metallic glass-forming liquid is found to be not strongly correlating thermodynamically, but its average dynamics, dynamic heterogeneities including the high order dynamic correlation length, and static structure are still well described by thermodynamic scaling with the same scaling exponent γ. This may indicate that the metallic liquid could be treated as a single-parameter liquid. As an intrinsic material constant stemming from the fundamental interatomic interactions, γ is theoretically predicted from the thermodynamic fluctuations of the potential energy and the virial. Although γ is conventionally understood merely from the repulsive part of the inter-particle potentials, the strong correlation between γ and the Grüneisen parameter up to the accuracy of the Dulong-Petit approximation demonstrates the important roles of anharmonicity and attractive force of the interatomic potential in governing glass transition of metallic glassformers. These findings may shed light on how to understand metallic glass formation from the fundamental interatomic interactions. PMID:27634267

  14. Studies of liquid metal surfaces using Auger spectroscopy

    NASA Technical Reports Server (NTRS)

    Hardy, S.; Fine, J.

    1982-01-01

    The surface composition of liquid gallium-tin alloys is studied in an Auger electron spectrometer as a function of bulk composition and temperature. The sessile drop samples are cleaned by argon ion bombardment sputtering of the liquid. This technique produces surfaces that are entirely free of impurities within the sensitivity of the spectrometer and remain so for many days. Tin is found to be strongly adsorbed at the liquid-vacuum interface. Surface concentrations based on Auger measurements are found to be in reasonably good agreement with values calculated from surface tension measurements interpreted in terms of a monolayer depth distribution model for the adsorbed tin.

  15. Spectral emissivities and optical constants of electromagnetically levitated liquid metals as functions of temperature and wavelength

    NASA Technical Reports Server (NTRS)

    Krishnan, S.; Hauge, R. H.; Margrave, J. L.

    1989-01-01

    The development of a noncontact temperature measurement device utilizing rotating analyzer ellipsometry is described. The technique circumvents the necessity of spectral emissivity estimation by direct measurement concomittant with radiance brightness. Using this approach, the optical properties of electromagnetically levitated liquid metals Cu, Ag, Au, Ni, Pd, Pt, and Zr were measured in situ at four wavelengths and up to 600 K superheat in the liquid. The data suggest an increase in the emissivity of the liquid compared with the incandescent solid. The data also show moderate temperature dependence of the spectral emissivity. A few measurements of the optical properties of undercooled liquid metals were also conducted. The data for both solids and liquids show excellent agreement with available values in the literature for the spectral emissivities as well as the optical constants.

  16. Plasmon electro-optic effect in a subwavelength metallic nanograting with a nematic liquid crystal

    NASA Astrophysics Data System (ADS)

    Palto, S. P.; Barnik, M. I.; Kasyanova, I. V.; Geivandov, A. R.; Shtykov, N. M.; Artemov, V. V.; Gorkunov, M. V.

    2016-01-01

    The electro-optic effect in hybrid structures based on subwavelength metallic nanogratings in contact with a layer of a nematic liquid crystal has been experimentally studied. Metallic gratings are fabricated in the form of interdigitated electrodes, which makes it possible to use them not only as optical elements but also for the production of an electric field in a thin surface region of the layer of the liquid crystal. It has been shown that, owing to the electric-field-induced reorientation of molecules of the liquid crystal near the surface of the grating, it is possible to significantly control the spectral features of the transmission of light, which are caused by the excitation of surface plasmons. The electro-optic effect is superfast for liquid crystal devices because a change in the optical properties of the system requires the reorientation of molecules only in a very thin surface layer of the liquid crystal.

  17. Preventing Oxide Adhesion of Liquid Metal Alloys to Enable Actuation in Microfluidic Systems

    NASA Astrophysics Data System (ADS)

    Joshipura, Ishan; Johnson, Alexander; Ayers, Hudson; Dickey, Michael

    This work explores the wetting behavior of an oxide-coated liquid metal, eutectic alloy of gallium and indium (`EGaIn'), which remains a liquid at room temperature. Liquid metals uniquely combine fluidity with metallic properties. Combined, these properties enable soft, stretchable, and shape reconfigurable electronics with `softer than skin' interfaces. Ga forms spontaneously a thin surface oxide that alters its wetting behavior and makes it difficult to move across surfaces without leaving residue behind. We examine the effects of surface roughness (i.e., Cassie-Baxter state) and lubrication to minimize adhesion of Ga oxide to surfaces. Lubricated surfaces create a `slip-layer' of liquid between the metal and surface that also inhibits wetting. This slip layer allows the metal to move reversibly through microchannels by preventing adhesion of the oxide. The metal may be pumped or moved by using low voltages or pneumatic actuation. Optical microscopy confirms the importance of the slip-layer, which enables non-stick motion of the metal through capillaries. Finally, electrochemical impedance spectroscopy characterizes the electrohydrodynanic motion of EGaIn in capillary systems.

  18. Chemical reactions of metal powders with organic and inorganic liquids during ball milling

    NASA Technical Reports Server (NTRS)

    Arias, A.

    1975-01-01

    Chromium and/or nickel powders were milled in metal chlorides and in organic liquids representative of various functional groups. The powders always reacted with the liquid and became contaminated with elements from them. The milled powders had specific surface areas ranging from 0.14 to 37 sq m/g, and the total contamination with elements from the milling liquid ranged from 0.01 to 56 weight percent. Compounds resulting from substitution, addition, or elimination reactions formed in or from the milling liquid.

  19. Eutectic-based ionic liquids with metal-containing anions and cations.

    PubMed

    Abbott, Andrew P; Barron, John C; Ryder, Karl S; Wilson, David

    2007-01-01

    Eutectic mixtures of zinc chloride and donor molecules such as urea and acetamide are described and it is proposed that these constitute a new class of ionic liquids. FAB-MS analysis shows that the liquids are made up of metal-containing anions and cations in which the donor is coordinated to the cation. Data on the viscosity, conductivity, density, phase behaviour and surface tension are presented and these are shown to be significantly different to other related ionic liquids that incorporate quaternary ammonium salts. The conductivity and viscosity are comparable with other ionic liquids and the data fit well to the Hole theory model recently proposed. PMID:17477454

  20. Metallotropic liquid crystals formed by surfactant templating of molten metal halides.

    PubMed

    Martin, James D; Keary, Cristin L; Thornton, Todd A; Novotnak, Mark P; Knutson, Jeremey W; Folmer, Jacob C W

    2006-04-01

    Liquid crystals consist of anisotropic molecular units, and most are organic molecules. Materials incorporating metals into anisotropic molecules, described as metallomesogens, have been prepared. Anisotropic structures such as one-dimensional chains and two-dimensional layers are frequently observed in solid-state inorganic materials, however, little is understood about structural organization in melts of such materials. Achieving liquid-crystalline behaviour in inorganic fluids should be possible if the anisotropic structure can be retained or designed into the molten phase. We demonstrated the ability to engineer zeolite-type structures into metal halide glasses and liquids. In this work we have engineered lamellar, cubic and hexagonal liquid-crystalline structure in metal-halide melts by controlling the volume fraction and nature of the inorganic block (up to 80 mol%) with respect to alkylammonium surfactants. The high metal content of these liquid-crystalline systems significantly advances the field of metallomesogens, which seeks to combine magnetic, electronic, optical, redox and catalytic properties common to inorganic materials with the fluid properties of liquid crystals. PMID:16547520

  1. Velocity-density systematics of liquid indium and the validity of the Birch's law for a liquid metal

    NASA Astrophysics Data System (ADS)

    Kato, J.; Komabayashi, T.; Hirose, K.; Baron, A. Q.; Tsutsui, S.; Ohishi, Y.

    2011-12-01

    The Earth's core is composed mostly of iron with some amounts of light element(s). In order to put constraints on the composition of the core, high-pressure (P) and -temperature (T) elastic properties and density of both solid and liquid iron and iron compounds are of quite importance. The Birch's law which suggests that the compressional velocity would change linearly with density, has been applied to the discussion of the core composition, since it does not require temperature of the core which is one of the most difficult parameters to constrain. Assuming the Birch's law, 300-K compression experiments of solid iron or iron compounds in a diamond anvil cell (DAC) can directly address the velocity-density relations of the inner core. On the other hand, the velocity-density relation for liquid iron has not been studied in the DAC since it requires high-temperatures. Here we investigated both velocity and density of a liquid metal, in order to study the validity of the Birch's law for the liquid metal. Since the melting temperature of iron is very high, we chose indium whose melting temperature is 430 K at 1 bar. For sound velocity measurements of liquid indium, we conducted inelastic X-ray scattering measurements in an externally heated DAC. The inelastic X-ray scattering measurements were conducted at the BL35XU, SPring-8 (Japan). We collected the data of solid and liquid phases at 10 different pressure and temperature conditions. The maximum P-T condition was 9 GPa and 750 K. The melting was confirmed by the two dimensional X-ray diffraction images. For density measurements, in-situ X-ray absorption experiments in the externally heated DAC were conducted at the BL10XU, SPring-8. Dual holes are drilled in the rhenium gasket and each hole was filled with either indium or NaCl. X-ray transmission intensities were measured by a photodiode across the sample and the standard material (NaCl). Assuming the Lambert-Beer law, we estimated the density of liquid indium up to

  2. Molecular dynamics simulations of bubble formation and cavitation in liquid metals.

    SciTech Connect

    Insepov, Z.; Hassanein, A.; Bazhirov, T. T.; Norman, G. E.; Stegailov, V. V.; Mathematics and Computer Science; Inst. for High Energy Densities of Joint Inst. for High Temperatures of RAS

    2007-11-01

    Thermodynamics and kinetics of nano-scale bubble formation in liquid metals such as Li and Pb were studied by molecular dynamics (MD) simulations at pressures typical for magnetic and inertial fusion. Two different approaches to bubble formation were developed. In one method, radial densities, pressures, surface tensions, and work functions of the cavities in supercooled liquid lithium were calculated and compared with the surface tension experimental data. The critical radius of a stable cavity in liquid lithium was found for the first time. In the second method, the cavities were created in the highly stretched region of the liquid phase diagram; and then the stability boundary and the cavitation rates were calculated in liquid lead. The pressure dependences of cavitation frequencies were obtained over the temperature range 700-2700 K in liquid Pb. The results of MD calculations for cavitation rate were compared with estimates of classical nucleation theory (CNT).

  3. Positive-electrode current collector for liquid-metal cells

    DOEpatents

    Shimotake, H.; Bartholme, L.G.

    1982-09-27

    A current collector for the positive electrode of an electrochemical cell with a positive electrode including a sulfide. The cell also has a negative electrode and a molten salt electrolyte including halides of a metal selected from the alkali metals and the alkaline earth metals in contact with both the positive and negative electrodes. The current collector has a base metal of copper, silver, gold, aluminum or alloys thereof with a coating thereon of iron, nickel, chromium or alloys thereof. The current collector when subjected to cell voltage forms a sulfur-containing compound on the surface thereby substantially protecting the current collector from further attack by sulfur ions during cell operation. Both electroless and electrolytic processes may be used to deposit coatings.

  4. Positive electrode current collector for liquid metal cells

    DOEpatents

    Shimotake, Hiroshi; Bartholme, Louis G.

    1984-01-01

    A current collector for the positive electrode of an electrochemical cell with a positive electrode including a sulfide. The cell also has a negative electrode and a molten salt electrolyte including halides of a metal selected from the alkali metals and the alkaline earth metals in contact with both the positive and negative electrodes. The current collector has a base metal of copper, silver, gold, aluminum or alloys thereof with a coating thereon of iron, nickel, chromium or alloys thereof. The current collector when subjected to cell voltage forms a sulfur-containing compound on the surface thereby substantially protecting the current collector from further attack by sulfur ions during cell operation. Both electroless and electrolytic processes may be used to deposit coatings.

  5. On the Shape of Liquid Metal Droplets in Electromagnetic Levitation Experiments

    NASA Technical Reports Server (NTRS)

    Schwartz, E.; Sauerland, S.; Szekely, J.; Egry, I.

    1993-01-01

    We present calculations and measurements on the shape of liquid metal droplets in electromagnetic levitation experiments. A normal stress balance model was developed to predict the shapes of liquid metal droplets that will be obtained in a microgravity experiment to measure the viscosity and surface tension of undercooled metals. This model was tested by calculating the droplet shapes in containerless experiments conducted to determine the surface tension of liquid metals. Inconsistencies associated with the results of a previous paper are elucidated. The computational results of the mathematical model are compared with the results of ground-based experiments for two different metals. The importance of the ratio of electromagnetic skin depth-to-droplet radius to the accuracy of the mathematical model is discussed. A planned alternate approach to modeling the shape by consideration of the entire droplet rather than only the surface is presented. As an example of an application. the influence of the shape on the splitting of the surface oscillation modes of levitated liquid metal droplets is discussed.

  6. Liquid wastes and industrial sludge. New investigation fields to recycle metals

    SciTech Connect

    Meux, E.; Leclerc, N.; Peneliau, F.; Muller, P.

    1999-07-01

    The aim of this work is to propose some alternatives to the landfilling of metallic hydroxide sludge coming from the classical physico-chemical treatment of liquid wastes containing metallic cations. A downstream treatment was investigated. It consists of a selective leaching of filter-press cakes. This chemical treatment allows the elimination of toxic metals from the sludge and produces an inertized residue. An upstream treatment was studied: the selective precipitation of metallic cations. In this case, it is possible to obtain zinc sulfide and iron oxide. These products meet the acceptance conditions for the zinc and steel industry.

  7. Production of aluminium metal matrix composites by liquid processing methods

    NASA Astrophysics Data System (ADS)

    Hynes, N. Rajesh Jesudoss; Kumar, R.; Tharmaraj, R.; Velu, P. Shenbaga

    2016-05-01

    Owing to high strength to low weight ratio, Aluminium matrix composites are widely used in diverse applications of many industries. This lucrative property is achieved by reinforcing the brittle ceramic particles in the aluminium matrix. Aluminium matrix composites are produced by liquid processing methods and solid processing methods. Nevertheless, liquidprocessing techniques stand out because of its simplicity and its suitability for mass production. In this review article, the production of aluminium matrix composites by different liquid processing technique is discussed and a comparative study is carried out.

  8. Liquid-metal-fed Pulsed Plasma Thrusters for In-space Propulsion

    NASA Technical Reports Server (NTRS)

    Markusic, Thomas E.

    2004-01-01

    Liquid metal propellants may provide a path toward more reliable and efficient pulsed plasma thrusters (PPTs). Conceptual thruster designs which eliminate the need for high current switches and propellant metering valves are described. Propellant loading techniques are suggested that show promise to increase thruster propellant utilization, dynamic, and electrical efficiency. Calibration results from a compact, electromagnetically-pumped propellant feed system are presented. Results for lithium and gallium propellants show capability to meter propellant at flow rates up to 10 +/- 0.1 mg/s. Experiments investigating the initiation of arc discharges using liquid metal droplets are presented. High speed photography and laser interferometry provide spatially and temporally resolved information on the decomposition of liquid metal droplets , and the evolution of the accelerating current channel.

  9. Linking structure to fragility in bulk metallic glass-forming liquids

    SciTech Connect

    Wei, Shuai E-mail: m.stolpe@mx.uni-saarland.de; Stolpe, Moritz E-mail: m.stolpe@mx.uni-saarland.de; Gross, Oliver; Gallino, Isabella; Hembree, William; Busch, Ralf; Evenson, Zach; Bednarcik, Jozef; Kruzic, Jamie J.

    2015-05-04

    Using in-situ synchrotron X-ray scattering, we show that the structural evolution of various bulk metallic glass-forming liquids can be quantitatively connected to their viscosity behavior in the supercooled liquid near T{sub g}. The structural signature of fragility is identified as the temperature dependence of local dilatation on distinct key atomic length scales. A more fragile behavior results from a more pronounced thermally induced dilatation of the structure on a length scale of about 3 to 4 atomic diameters, coupled with shallower temperature dependence of structural changes in the nearest neighbor environment. These findings shed light on the structural origin of viscous slowdown during undercooling of bulk metallic glass-forming liquids and demonstrate the promise of predicting the properties of bulk metallic glasses from the atomic scale structure.

  10. Crystalline monolayer surface of liquid Au-Cu-Si-Ag-Pd: Metallic glass former

    SciTech Connect

    Mechler, S; Yahel, E; Pershan, P S; Meron, M; Lin, B

    2012-02-06

    It is demonstrated by means of x-ray synchrotron reflectivity and diffraction that the surface of the liquid phase of the bulk metallic glass forming alloy Au49Cu26.9Si16.3Ag5.5Pd2.3 consists of a two-dimensional crystalline monolayer phase for temperatures of up to about 50 K above the eutectic temperature. The present alloy as well as glass forming Au82Si18 and Au-Si-Ge alloys containing small amounts of Ge are the only metallic liquids to exhibit surface freezing well above the melting temperature. This suggests that the phenomena of surface freezing in metallic liquids and glass forming ability are related and probably governed by similar physical properties.

  11. Analysis of impingement heat transfer for two parallel liquid-metal slot jets

    NASA Technical Reports Server (NTRS)

    Siegel, R.

    1974-01-01

    An analytical method is developed for determining heat transfer by impinging liquid-metal slot jets. The method involves mapping the jet flow region, which is bounded by free streamlines, into a potential plane where it becomes a uniform flow in a channel of constant width. The energy equation is transformed into potential plane coordinates and is solved in the channel flow region. Conformal mapping is then used to transform the solution back into the physical plane and obtain the desired heat-transfer characteristics. The analysis given here determines the heat-transfer characteristics for two parallel liquid-metal slot jets impinging normally against a uniformly heated flat plate. The liquid-metal assumptions are made that the jets are inviscid and that molecular conduction is dominating heat diffusion. Wall temperature distributions along the heated plate are obtained as a function of spacing between the jets and the jet Peclet number.

  12. Development of a lithium liquid metal ion source for MeV ion beam analysis

    SciTech Connect

    Read, P.M.; Maskrey, J.T.; Alton, G.D.

    1988-01-01

    Lithium liquid metal ion sources are an attractive complement to the existing gaseous ion sources that are extensively used for ion beam analysis. This is due in part to the high brightness of the liquid metal ion source and in part to the availability of a lithium ion beam. High brightness is of particular importance to MeV ion microprobes which are now approaching current density limitations on targets determined by the ion source. The availability of a lithium beam provides increased capabilities for hydrogen profiling and high resolution Rutherford backscattering spectrometry. This paper describes the design and performance of a lithium liquid metal ion source suitable for use on a 5MV Laddertron accelerator. Operational experience with the source and some of its uses for ion beam analysis are discussed. 8 refs., 2 figs.

  13. Performance test of electromagnetic pump on heavy liquid metal in PREKY-I facility

    NASA Astrophysics Data System (ADS)

    li, X. L.; Ma, X. D.; Zhu, Z. Q.; Li, Y.; Lv, K. F.

    2016-05-01

    Pump is a key sub-system which drives the heavy liquid metal circulation in experimental loops. In the paper, the hydraulic and mechanical performances of an electromagnetic pump (EMP) were tested in the liquid metal test facility named PREKY-I. The test results showed that the EMP worked at good state when the working current was up to 170 ampere. In this condition, the flow rate was 5m3/h, and pressure head 7.5bar, when the outlet temperature was kept at 380°C during the test. The performance was close to the expected design parameters. The EMP had run continuously for 200 hours with stable performance. From the test results, the EMP could be used in KYLIN-II loop, which is the upgrade liquid metal test loop of PREKY-I.

  14. Electrolytic reduction of liquid metal oxides and its application to reconfigurable structured devices

    NASA Astrophysics Data System (ADS)

    Wang, Jinqi; Appusamy, Kanagasundar; Guruswamy, Sivaraman; Nahata, Ajay

    2015-03-01

    Structured metallic patterns are routinely used for a wide variety of applications, ranging from electronic circuits to plasmonics and metamaterials. Numerous techniques have been developed for the fabrication of these devices, in which the metal patterns are typically formed using conventional metals. While this approach has proven very successful, it does generally limit the ability to reconfigure the geometry of the overall device. Here, we demonstrate the ability to create artificially structured metallic devices using liquid metals, in which the configuration can be altered via the electrolysis of saline solutions or deionized water. We accomplish this using an elastomeric mold with two different sets of embedded microfluidic channels that are patterned and injected with EGaIn and water, respectively. The electrochemical reaction is then used to etch the thin oxide layer that forms on eutectic gallium indium (EGaIn) in a controlled reproducible manner. Once the oxide layer is dissolved locally, the underlying liquid metal retracts away from the original position to a position where a new stable oxide layer can reform, which is equivalent to erasing a section of the liquid metal. To allow for full reconfigurability, the entire device can be reset by refilling all of the microchannels with EGaIn.

  15. Electrolytic reduction of liquid metal oxides and its application to reconfigurable structured devices

    PubMed Central

    Wang, Jinqi; Appusamy, Kanagasundar; Guruswamy, Sivaraman; Nahata, Ajay

    2015-01-01

    Structured metallic patterns are routinely used for a wide variety of applications, ranging from electronic circuits to plasmonics and metamaterials. Numerous techniques have been developed for the fabrication of these devices, in which the metal patterns are typically formed using conventional metals. While this approach has proven very successful, it does generally limit the ability to reconfigure the geometry of the overall device. Here, we demonstrate the ability to create artificially structured metallic devices using liquid metals, in which the configuration can be altered via the electrolysis of saline solutions or deionized water. We accomplish this using an elastomeric mold with two different sets of embedded microfluidic channels that are patterned and injected with EGaIn and water, respectively. The electrochemical reaction is then used to etch the thin oxide layer that forms on eutectic gallium indium (EGaIn) in a controlled reproducible manner. Once the oxide layer is dissolved locally, the underlying liquid metal retracts away from the original position to a position where a new stable oxide layer can reform, which is equivalent to erasing a section of the liquid metal. To allow for full reconfigurability, the entire device can be reset by refilling all of the microchannels with EGaIn. PMID:25727894

  16. Lunar Oxygen Production and Metals Extraction Using Ionic Liquids

    NASA Technical Reports Server (NTRS)

    Marone, Matthew; Paley, Mark Steven; Donovan, David N.; Karr, Laurel J.

    2009-01-01

    Initial results indicate that ionic liquids are promising media for the extraction of oxygen from lunar regolith. IL acid systems can solubilize regolith and produce water with high efficiency. IL electrolytes are effective for water electrolysis, and the spent IL acid media are capable of regeneration.

  17. Metal corrosion in a supercritical carbon dioxide - liquid sodium power cycle.

    SciTech Connect

    Moore, Robert Charles; Conboy, Thomas M.

    2012-02-01

    A liquid sodium cooled fast reactor coupled to a supercritical carbon dioxide Brayton power cycle is a promising combination for the next generation nuclear power production process. For optimum efficiency, a microchannel heat exchanger, constructed by diffusion bonding, can be used for heat transfer from the liquid sodium reactor coolant to the supercritical carbon dioxide. In this work, we have reviewed the literature on corrosion of metals in liquid sodium and carbon dioxide. The main conclusions are (1) pure, dry CO{sub 2} is virtually inert but can be highly corrosive in the presence of even ppm concentrations of water, (2) carburization and decarburization are very significant mechanism for corrosion in liquid sodium especially at high temperature and the mechanism is not well understood, and (3) very little information could be located on corrosion of diffusion bonded metals. Significantly more research is needed in all of these areas.

  18. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 10: Liquid-metal MHD systems. [energy conversion efficiency of electric power plants using liquid metal magnetohydrodynamics

    NASA Technical Reports Server (NTRS)

    Holman, R. R.; Lippert, T. E.

    1976-01-01

    Electric Power Plant costs and efficiencies are presented for two basic liquid-metal cycles corresponding to 922 and 1089 K (1200 and 1500 F) for a commercial applications using direct coal firing. Sixteen plant designs are considered for which major component equipment were sized and costed. The design basis for each major component is discussed. Also described is the overall systems computer model that was developed to analyze the thermodynamics of the various cycle configurations that were considered.

  19. Multiphysics analysis of liquid metal annular linear induction pumps: A project overview

    DOE PAGES

    Maidana, Carlos Omar; Nieminen, Juha E.

    2016-03-14

    Liquid metal-cooled fission reactors are both moderated and cooled by a liquid metal solution. These reactors are typically very compact and they can be used in regular electric power production, for naval and space propulsion systems or in fission surface power systems for planetary exploration. The coupling between the electromagnetics and thermo-fluid mechanical phenomena observed in liquid metal thermo-magnetic systems for nuclear and space applications gives rise to complex engineering magnetohydrodynamics and numerical problems. It is known that electromagnetic pumps have a number of advantages over rotating mechanisms: absence of moving parts, low noise and vibration level, simplicity of flowmore » rate regulation, easy maintenance and so on. However, while developing annular linear induction pumps, we are faced with a significant problem of magnetohydrodynamic instability arising in the device. The complex flow behavior in this type of devices includes a time-varying Lorentz force and pressure pulsation due to the time-varying electromagnetic fields and the induced convective currents that originates from the liquid metal flow, leading to instability problems along the device geometry. The determinations of the geometry and electrical configuration of liquid metal thermo-magnetic devices give rise to a complex inverse magnetohydrodynamic field problem were techniques for global optimization should be used, magnetohydrodynamics instabilities understood –or quantified- and multiphysics models developed and analyzed. Lastly, we present a project overview as well as a few computational models developed to study liquid metal annular linear induction pumps using first principles and the a few results of our multi-physics analysis.« less

  20. Efficient separation of transition metals from rare earths by an undiluted phosphonium thiocyanate ionic liquid.

    PubMed

    Rout, Alok; Binnemans, Koen

    2016-06-21

    The ionic liquid trihexyl(tetradecyl)phosphonium thiocyanate has been used for the extraction of the transition metal ions Co(ii), Ni(ii), Zn(ii), and the rare-earth ions La(iii), Sm(iii) and Eu(iii) from aqueous solutions containing nitrate or chloride salts. The transition metal ions showed a high affinity for the ionic liquid phase and were efficiently extracted, while the extraction efficiency of the rare-earth ions was low. This difference in extraction behavior enabled separation of the pairs Co(ii)/Sm(iii), Ni(ii)/La(iii) and Zn(ii)/Eu(iii). These separations are relevant for the recycling of rare earths and transition metals from samarium cobalt permanent magnets, nickel metal hydride batteries and lamp phosphors, respectively. The extraction of metal ions from a chloride or nitrate solution with a thiocyanate ionic liquid is an example of "split-anion extraction", where different anions are present in the aqueous and ionic liquid phase. Close to 100% loading was possible for Co(ii) and Zn(ii) up to a concentration of 40 g L(-1) of the transition metal salt in the initial aqueous feed solution, whereas the extraction efficiency for Ni(ii) gradually decreased with increase in the initial feed concentration. Stripping of Co(ii), Zn(ii) and Ni(ii) from the loaded ionic liquid phase was possible by a 15 wt% NH3 solution. The ionic liquid could reused after extraction and stripping. PMID:27243450

  1. Modeling of the mass transfer rates of metal ions across supported liquid membranes. 1: Theory

    SciTech Connect

    Elhassadi, A.A.; Do, D.D.

    1999-01-01

    This paper deals with the modeling of the transport and separation of metal ions across supported liquid membranes. The mass transfer resistance at the liquid-membrane interfaces and the interfacial chemical reactions at both the extracting side and the stripping side are taken into account in the model equations. Simple analysis of the time scale of the system shows the influence of various important parameters and their interactions on the overall transport rate. Parametric studies are also dealt with in this paper.

  2. Liquid-liquid extraction of metal ions by the 6-membered N-containing macrocycle hexacyclen.

    PubMed

    Arpadjan, S; Mitewa, M; Bontchev, P R

    1987-11-01

    The nitrogen-containing analogue of 18-crown-6, 1,4,7,10,13,16-hexa-azaoctadecane (hexacyclen)] was studied as a reagent for complexation and extraction of some metal ions. It was found that with this reagent and methyl isobutyl ketone, metal ions such as silver(I), mercury(II), copper(II), platinum(II) and palladium(II) can be quantitatively extracted and separated from iron(III) and some other metal ions.

  3. Photolithography-Based Patterning of Liquid Metal Interconnects for Monolithically Integrated Stretchable Circuits.

    PubMed

    Park, Chan Woo; Moon, Yu Gyeong; Seong, Hyejeong; Jung, Soon Won; Oh, Ji-Young; Na, Bock Soon; Park, Nae-Man; Lee, Sang Seok; Im, Sung Gap; Koo, Jae Bon

    2016-06-22

    We demonstrate a new patterning technique for gallium-based liquid metals on flat substrates, which can provide both high pattern resolution (∼20 μm) and alignment precision as required for highly integrated circuits. In a very similar manner as in the patterning of solid metal films by photolithography and lift-off processes, the liquid metal layer painted over the whole substrate area can be selectively removed by dissolving the underlying photoresist layer, leaving behind robust liquid patterns as defined by the photolithography. This quick and simple method makes it possible to integrate fine-scale interconnects with preformed devices precisely, which is indispensable for realizing monolithically integrated stretchable circuits. As a way for constructing stretchable integrated circuits, we propose a hybrid configuration composed of rigid device regions and liquid interconnects, which is constructed on a rigid substrate first but highly stretchable after being transferred onto an elastomeric substrate. This new method can be useful in various applications requiring both high-resolution and precisely aligned patterning of gallium-based liquid metals. PMID:27250997

  4. Photolithography-Based Patterning of Liquid Metal Interconnects for Monolithically Integrated Stretchable Circuits.

    PubMed

    Park, Chan Woo; Moon, Yu Gyeong; Seong, Hyejeong; Jung, Soon Won; Oh, Ji-Young; Na, Bock Soon; Park, Nae-Man; Lee, Sang Seok; Im, Sung Gap; Koo, Jae Bon

    2016-06-22

    We demonstrate a new patterning technique for gallium-based liquid metals on flat substrates, which can provide both high pattern resolution (∼20 μm) and alignment precision as required for highly integrated circuits. In a very similar manner as in the patterning of solid metal films by photolithography and lift-off processes, the liquid metal layer painted over the whole substrate area can be selectively removed by dissolving the underlying photoresist layer, leaving behind robust liquid patterns as defined by the photolithography. This quick and simple method makes it possible to integrate fine-scale interconnects with preformed devices precisely, which is indispensable for realizing monolithically integrated stretchable circuits. As a way for constructing stretchable integrated circuits, we propose a hybrid configuration composed of rigid device regions and liquid interconnects, which is constructed on a rigid substrate first but highly stretchable after being transferred onto an elastomeric substrate. This new method can be useful in various applications requiring both high-resolution and precisely aligned patterning of gallium-based liquid metals.

  5. Packaging a liquid metal ESD with micro-scale Mercury droplet.

    SciTech Connect

    Barnard, Casey Anderson

    2011-08-01

    A liquid metal ESD is being developed to provide electrical switching at different acceleration levels. The metal will act as both proof mass and electric contact. Mercury is chosen to comply with operation parameters. There are many challenges surrounding the deposition and containment of micro scale mercury droplets. Novel methods of micro liquid transfer are developed to deliver controllable amounts of mercury to the appropriate channels in volumes under 1 uL. Issues of hermetic sealing and avoidance of mercury contamination are also addressed.

  6. Updated reference design of a liquid metal cooled tandem mirror fusion breeder

    SciTech Connect

    Berwald, D.H.; Whitley, R.H.; Garner, J.K.; Gromada, R.J.; McCarville, T.J.; Moir, R.W.; Lee, J.D.; Bandini, B.R.; Fulton, F.J.; Wong, C.P.C.; Maya, I.; Hoot, C.G.; Schultz, K.R.; Miller, L.G.; Beeston, J.M.; Harris, B.L.; Westman, R.A.; Ghoniem, N.M.; Orient, G.; Wolfer, M.; DeVan, J.H.; Torterelli, P.

    1985-09-01

    Detailed studies of key techinical issues for liquid metal cooled fusion breeder (fusion-fission hybrid blankets) have been performed during the period 1983-4. Based upon the results of these studies, the 1982 reference liquid metal cooled tandem mirror fusion breeder blanket design was updated and is described. The updated reference blankets provides increased breeding and lower technological risk in comparison with the original reference blanket. In addition to the blanket design revisions, a plant concept, cost, and fuel cycle economics assessment is provided. The fusion breeder continues to promise an economical source of fissile fuel for the indefinite future.

  7. Inverse correlation between cohesive energy and thermal expansion coefficient in liquid transition metal alloys.

    PubMed

    Gangopadhyay, A K; Bendert, J C; Mauro, N A; Kelton, K F

    2012-09-19

    The volume expansion coefficients (α) of twenty-five glass-forming transition metal alloy liquids, measured using the electrostatic levitation technique, are reported. An inverse correlation between α and the cohesive energy is found. The predicted values of α from this relationship agree reasonably well with the published data for thirty other transition metal and alloy liquids; some disagreement was found for a few alloys containing significant amounts of group III and IV elements. A theoretical argument for this empirical relationship is presented. PMID:22842287

  8. Analysis of heat transfer for a normally impinging liquid-metal slot jet

    NASA Technical Reports Server (NTRS)

    Siegel, R.

    1973-01-01

    A two-dimensional liquid-metal slot jet that is impinging normally against a uniformly heated flat plate is analyzed. The distributions of wall temperature and heat-transfer coefficient are obtained as functions of position along the plate. The liquid-metal assumptions are made that the jet is inviscid and that molecular condition is dominating heat diffusion. The solution is obtained by mapping the jet flow region into a potential plane where it occupies a strip of uniform width. The energy equation is transformed into potential coordinates, and an exact solution obtained in the strip region. Conformal mapping is then used to transform the solution into the physical plane.

  9. Empirical relation between surface tension and density for some pure liquid metals

    NASA Astrophysics Data System (ADS)

    Ceotto, D.

    2015-12-01

    A new investigation is conducted on the experimental values of surface tension and density for some common pure liquid metals. Using the most recent and accredited data a new relation is found between these values for Au, Cu, Sn, Al, Pb, In, Bi, Ni, Co, Fe, Ba, Na, Nd, Ga, and Sb. The proportion constant has then been calculated giving an accuracy R2 equal to about 0.98. The equation proposed finds agreement with other theoretical models present in literature; it can be used by engineers in many industrial fields to predict the variables but also to simulate macroscopic processes involving liquid metals.

  10. X-ray grating interferometry with a liquid-metal-jet source

    SciTech Connect

    Thüring, T.; Rutishauser, S.; Stampanoni, M.; Zhou, T.; Lundström, U.; Burvall, A.; Hertz, H. M.; David, C.

    2013-08-26

    A liquid-metal-jet X-ray tube is used in an X-ray phase-contrast microscope based on a Talbot type grating interferometer. With a focal spot size in the range of a few microns and a photon flux of ∼10{sup 12} photons/s×sr, the brightness of such a source is approximately one order of magnitude higher than for a conventional microfocus source. For comparison, a standard microfocus source was used with the same grating interferometer, showing significantly increased visibility for the liquid-metal-jet arrangement. Together with the increased flux, this results in improved signal-to-noise ratio.

  11. Double-sided electromagnetic pump with controllable normal force for rapid solidification of liquid metals

    DOEpatents

    Kuznetsov, S.B.

    1987-01-13

    A system for casting liquid metals is provided with an electromagnetic pump which includes a pair of primary blocks each having a polyphase winding and being positioned to form a gap through which a movable conductive heat sink passes. A solidifying liquid metal sheet is deposited on the heat sink and the heat sink and sheet are held in compression by forces produced as a result of current flow through the polyphase windings. Shaded-pole interaction between the primary windings, heat sink and solidifying strip produce transverse forces which act to center the strip on the heat sink. 5 figs.

  12. Double-sided electromagnetic pump with controllable normal force for rapid solidification of liquid metals

    DOEpatents

    Kuznetsov, Stephen B.

    1987-01-01

    A system for casting liquid metals is provided with an electromagnetic pump which includes a pair of primary blocks each having a polyphase winding and being positioned to form a gap through which a movable conductive heat sink passes. A solidifying liquid metal sheet is deposited on the heat sink and the heat sink and sheet are held in compression by forces produced as a result of current flow through the polyphase windings. Shaded-pole interaction between the primary windings, heat sink and solidifying strip produce transverse forces which act to center the strip on the heat sink.

  13. Onset of Cooperative Dynamics in an Equilibrium Glass-Forming Metallic Liquid

    DOE PAGES

    Jaiswal, Abhishek; O’Keeffe, Stephanie; Mills, Rebecca; Podlesynak, Andrey; Ehlers, Georg; Dmowski, Wojciech; Lokshin, Konstantin; Stevick, Joseph; Egami, Takeshi; Zhang, Yang

    2016-01-22

    Onset of cooperative dynamics has been observed in many molecular liquids, colloids, and granular materials in the metastable regime on approaching their respective glass or jamming transition points, and is considered to play a significant role in the emergence of the slow dynamics. However, the nature of such dynamical cooperativity remains elusive in multicomponent metallic liquids characterized by complex many-body interactions and high mixing entropy. Herein, we report evidence of onset of cooperative dynamics in an equilibrium glass-forming metallic liquid (LM601: Zr51Cu36Ni4Al9). This is revealed by deviation of the mean effective diffusion coefficient from its high-temperature Arrhenius behavior below TAmore » ≈ 1300 K, i.e., a crossover from uncorrelated dynamics above TA to landscape-influenced correlated dynamics below TA. Moreover, the onset/ crossover temperature TA in such a multicomponent bulk metallic glass-forming liquid is observed at approximately twice of its calorimetric glass transition temperature (Tg ≈ 697 K) and in its stable liquid phase, unlike many molecular liquids.« less

  14. Onset of Cooperative Dynamics in an Equilibrium Glass-Forming Metallic Liquid.

    PubMed

    Jaiswal, Abhishek; O'Keeffe, Stephanie; Mills, Rebecca; Podlesynak, Andrey; Ehlers, Georg; Dmowski, Wojciech; Lokshin, Konstantin; Stevick, Joseph; Egami, Takeshi; Zhang, Yang

    2016-02-18

    Onset of cooperative dynamics has been observed in many molecular liquids, colloids, and granular materials in the metastable regime on approaching their respective glass or jamming transition points, and is considered to play a significant role in the emergence of the slow dynamics. However, the nature of such dynamical cooperativity remains elusive in multicomponent metallic liquids characterized by complex many-body interactions and high mixing entropy. Herein, we report evidence of onset of cooperative dynamics in an equilibrium glass-forming metallic liquid (LM601: Zr51Cu36Ni4Al9). This is revealed by deviation of the mean effective diffusion coefficient from its high-temperature Arrhenius behavior below TA ≈ 1300 K, i.e., a crossover from uncorrelated dynamics above TA to landscape-influenced correlated dynamics below TA. Furthermore, the onset/crossover temperature TA in such a multicomponent bulk metallic glass-forming liquid is observed at approximately twice of its calorimetric glass transition temperature (Tg ≈ 697 K) and in its stable liquid phase, unlike many molecular liquids. PMID:26798946

  15. Determination of metal ions by high-performance liquid chromatographic separation of their hydroxamic acid chelates

    SciTech Connect

    Palmieri, M.D.; Fritz, J.S.

    1987-09-15

    Metal ions are determined by adding N-methylfurohydroxamic acid to an aqueous sample and then separating the metal chelates by direct injection onto a liquid chromatographic column. Separations on a C/sub 8/ silica column and a polystyrene-divinylbenzene column are compared, with better separations seen on the polymeric column. The complexes formed at low pH values are cationic and are separated by an ion pairing mechanism. Retention times and selectivity of the metal complexes can be varied by changing the pH. Several metal ions can be separated and quantified; separation conditions, linear calibration curve ranges, and detection limits are presented for Zr(IV), Hf(IV), Fe(III), Nb(V), Al(III), and Sb(III). Interferences due to the presence of other ions in solution are investigated. Finally, an antiperspirant sample is analyzed for zirconium by high-performance liquid chromatography.

  16. Controlling Surface Chemistry of Gallium Liquid Metal Alloys to Enhance their Fluidic Properties

    NASA Astrophysics Data System (ADS)

    Ilyas, Nahid; Cumby, Brad; Cook, Alexander; Durstock, Michael; Tabor, Christopher; Materials; Manufacturing Directorate Team

    Gallium liquid metal alloys (GaLMAs) are one of the key components of emerging technologies in reconfigurable electronics, such as tunable radio frequency antennas and electronic switches. Reversible flow of GaLMA in microchannels of these types of devices is hindered by the instantaneous formation of its oxide skin in ambient environment. The oxide film sticks to most surfaces leaving unwanted metallic residues that can cause undesired electronic properties. In this report, residue-free reversible flow of a binary alloy of gallium (eutectic gallium indium) is demonstrated via two types of surface modifications where the oxide film is either protected by an organic thin film or chemically removed. An interface modification layer (alkyl phosphonic acids) was introduced into the microfluidic system to modify the liquid metal surface and protect its oxide layer. Alternatively, an ion exchange membrane was utilized as a 'sponge-like' channel material to store and slowly release small amounts of HCl to react with the surface oxide of the liquid metal. Characterization of these interfaces at molecular level by surface spectroscopy and microscopy provided with mechanistic details for the interfacial interactions between the liquid metal surface and the channel materials.

  17. Selective Single-Step Separation of a Mixture of Three Metal Ions by a Triphasic Ionic-Liquid-Water-Ionic-Liquid Solvent Extraction System.

    PubMed

    Vander Hoogerstraete, Tom; Blockx, Jonas; De Coster, Hendrik; Binnemans, Koen

    2015-08-10

    In a conventional solvent extraction system, metal ions are distributed between two immiscible phases, typically an aqueous and an organic phase. In this paper, the proof-of-principle is given for the distribution of metal ions between three immiscible phases, two ionic liquid phases with an aqueous phase in between them. Three-liquid-phase solvent extraction allows separation of a mixture of three metal ions in a single step, whereas at least two steps are required to separate three metals in the case of two-liquid-phase solvent extraction. In the triphasic system, the lower organic phase is comprised of the ionic liquid betainium- or choline bis(trifluoromethylsulfonyl)imide, whereas the upper organic phase is comprised of the ionic liquid trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide. The triphasic system was used for the separation of a mixture of tin(II), yttrium(III), and scandium(III) ions. PMID:26178665

  18. Liquid-metal binary cycles for stationary power

    NASA Technical Reports Server (NTRS)

    Gutstein, M.; Furman, E. R.; Kaplan, G. M.

    1975-01-01

    The use of topping cycles to increase electric power plant efficiency is discussed, with particular attention to mercury and alkali metal Rankine cycle systems that could be considered for topping cycle applications. An overview of this technology, possible system applications, the required development, and possible problem areas is presented.

  19. Laboratory experiments on liquid metal spherical-Couette flows

    NASA Astrophysics Data System (ADS)

    Andres Triana, Santiago; Lathrop, Daniel

    2005-11-01

    We present experimental observations on liquid sodium flow in a spherical-Couette geometry. By applying an external magnetic field we are able to clearly identify at least two induced magnetic field modes with different poloidal patterns as well as different azimuthal wave numbers. The origin of many of these induced field oscillations appears to be related to inertial wave oscillations propagating in the spherical annulus. Possible implications for dynamo action and to the magneto-rotational instability will also be discussed.

  20. Self-assembly of organic films on a liquid metal

    NASA Astrophysics Data System (ADS)

    Magnussen, Olaf M.; Ocko, Benjamin M.; Deutsch, Moshe; Regan, Michael J.; Pershan, Peter S.; Abernathy, Douglas; Grübel, Gerhard; Legrand, Jean-François

    1996-11-01

    THE structure and phase behaviour of organic thin films result from the subtle interplay of intermolecular Van der Waals interactions, which promote self-assembly and long-ranged order, and the more complex interactions between the end groups of the organic chains and the substrate. The structure of molecular films of amphiphiles has been extensively studied on subphases of dielectric liquids, notably water (Langmuir mono-layers) and on solid surfaces (self-assembled monolayers, SAMs)1-4. Here we report structural studies, by synchrotron X-ray scattering, of an intermediate case: densely packed alka-nethiol films on the surface of liquid mercury. While, like SAMs, these films form strong chemical bonds to the subphase, this subphase is smooth and unstructured, as in the case of Langmuir monolayers. But unlike either of these1,2,5-7, our films have no in-plane long-range order. We suggest that the strong interaction of the thiol group with the underlying disordered liquid dominates here over the order-promoting interactions of the alkyl chains.

  1. Economizer Based Data Center Liquid Cooling with Advanced Metal Interfaces

    SciTech Connect

    Timothy Chainer

    2012-11-30

    A new chiller-less data center liquid cooling system utilizing the outside air environment has been shown to achieve up to 90% reduction in cooling energy compared to traditional chiller based data center cooling systems. The system removes heat from Volume servers inside a Sealed Rack and transports the heat using a liquid loop to an Outdoor Heat Exchanger which rejects the heat to the outdoor ambient environment. The servers in the rack are cooled using a hybrid cooling system by removing the majority of the heat generated by the processors and memory by direct thermal conduction using coldplates and the heat generated by the remaining components using forced air convection to an air- to- liquid heat exchanger inside the Sealed Rack. The anticipated benefits of such energy-centric configurations are significant energy savings at the data center level. When compared to a traditional 10 MW data center, which typically uses 25% of its total data center energy consumption for cooling this technology could potentially enable a cost savings of up to $800,000-$2,200,000/year (assuming electricity costs of 4 to 11 cents per kilowatt-hour) through the reduction in electrical energy usage.

  2. Overview of EU activities on DEMO liquid metal breeder blanket

    SciTech Connect

    Giancarli, L.; Proust, E.

    1994-12-31

    The European test-blanket development programme, started in 1988, is aiming at the selection by 1995 of two DEMO-relevant blanket lines to be tested in ITER. At present, four lines of blanket are under development, two of them using solid and the other two liquid breeder materials. As far as liquid breeders are concerned, two lines of blankets have been selected within the European Union, the water-cooled lithium-lead (the eutectic Pb-17Li) blankets and the dual-coolant Pb-17Li blankets. Designs have been developed considering an agreed set of DEMO specifications, such as, for instance, a fusion power of 2,200 MW, a neutron wall-loading of 2MW/m{sup 2}, a life-time of 20,000 hours, and the use of martensitic steel as a structural material. Moreover, an experimental program has been set up in order to address the main critical issues for each line. The present paper gives an overview of both design and experimental activities within the European Union concerning these two lines of liquid breeder blankets.

  3. Performance investigations of liquid-metal heat pipes for space and terrestrial applications

    NASA Technical Reports Server (NTRS)

    Kemme, J. E.; Keddy, E. S.; Phillips, J. R.

    1978-01-01

    The high heat transfer capacity of liquid-metal heat pipes is demonstrated in performance tests with mercury, potassium, sodium, and lithium working fluids and wick structures which serve to minimize liquid pressure losses and vapor/liquid interactions. Appropriate wicks for horizontal and vertical operation are described. It is shown that heat-transfer with these wicks is limited by vapor flow effects. Examples are given of particular effects associated with a long adiabatic section between evaporator and condenser and with a heat source of uniform temperature as opposed to a source of uniform power.

  4. Liquid drop technique for generation of organic glass and metal shells

    NASA Technical Reports Server (NTRS)

    Hendricks, C. D.

    1982-01-01

    It was found that liquid drop techniques are very useful in several diverse areas. For producing very uniform metallic, organic, inorganic and, on particular, glassy shells, the liquid jet method is the most reproducible and exceptionally useful of all the techniques studied. The technique of capillary wave synchronization of the break-up of single and multiple component jets was utilized to produce uniform sized liquid drops and solid particles, and hollow liquid and solid shells. The technique was also used to encapsulate a number of liquids in impermeable spherical shells. Highly uniform glass shells were made by generating uniform drops of glass forming materials in an aqueous solution, subsequently evaporating the water, and then fusing and blowing the remaining solids in a high temperature vertical tube furnace. Experimental results are presented and the critical problems in further research in this field are discussed.

  5. Liquid metals as ultra-stretchable, soft, and shape reconfigurable conductors

    NASA Astrophysics Data System (ADS)

    Eaker, Collin B.; Dickey, Michael D.

    2015-05-01

    Conventional, rigid materials remain the key building blocks of most modern electronic devices, but they are limited in their ability to conform to curvilinear surfaces. It is possible to make electronic components that are flexible and in some cases stretchable by utilizing thin films, engineered geometries, or inherently soft and stretchable materials that maintain their function during deformation. Here, we describe the properties and applications of a micromoldable liquid metal that can form conductive components that are ultra-stretchable, soft, and shape-reconfigurable. This liquid metal is a gallium-based alloy with low viscosity and high conductivity. The metal develops spontaneously a thin, passivating oxide layer on the surface that allows the metal to be molded into non-spherical shapes, including films and wires, and patterned by direct-write techniques or microfluidic injection. Furthermore, unlike mercury, the liquid metal has low toxicity and negligible vapor pressure. This paper discusses the mechanical and electrical properties of the metal in the context of electronics, and discusses how the properties of the oxide layer have been exploited for new patterning techniques that enable soft, stretchable and reconfigurable devices.

  6. Deposition of metal films on an ionic liquid as a basis for a lunar telescope

    NASA Astrophysics Data System (ADS)

    Borra, Ermanno F.; Seddiki, Omar; Angel, Roger; Eisenstein, Daniel; Hickson, Paul; Seddon, Kenneth R.; Worden, Simon P.

    2007-06-01

    An optical/infrared telescope of 20-100m aperture located on the Moon would be able to observe objects 100 to 1,000 times fainter than the proposed next generation of space telescopes. The infrared region of the spectrum is particularly important for observations of objects at redshifts z>7. The apparent simplicity and low mass of a liquid mirror telescope, compared with a traditional pointable glass mirror, suggest that the concept should be considered further. A previously proposed liquid mirror telescope, based upon a spinning liquid metallic alloy, is not appropriate for infrared applications, which will require a liquid below 130K. Here we report the successful coating of an ionic liquid with silver. The surface is smooth and the silver coating is stable on a timescale of months. The underlying ionic liquid does not evaporate in a vacuum and remains liquid down to a temperature of 175K. Given that there are ~106 simple and ~1018 ternary ionic liquids, it should be possible to synthesize liquids with even lower melting temperatures.

  7. A Method to Manipulate Surface Tension of a Liquid Metal via Surface Oxidation and Reduction.

    PubMed

    Eaker, Collin B; Khan, M Rashed; Dickey, Michael D

    2016-01-26

    Controlling interfacial tension is an effective method for manipulating the shape, position, and flow of fluids at sub-millimeter length scales, where interfacial tension is a dominant force. A variety of methods exist for controlling the interfacial tension of aqueous and organic liquids on this scale; however, these techniques have limited utility for liquid metals due to their large interfacial tension. Liquid metals can form soft, stretchable, and shape-reconfigurable components in electronic and electromagnetic devices. Although it is possible to manipulate these fluids via mechanical methods (e.g., pumping), electrical methods are easier to miniaturize, control, and implement. However, most electrical techniques have their own constraints: electrowetting-on-dielectric requires large (kV) potentials for modest actuation, electrocapillarity can affect relatively small changes in the interfacial tension, and continuous electrowetting is limited to plugs of the liquid metal in capillaries. Here, we present a method for actuating gallium and gallium-based liquid metal alloys via an electrochemical surface reaction. Controlling the electrochemical potential on the surface of the liquid metal in electrolyte rapidly and reversibly changes the interfacial tension by over two orders of magnitude ( ̴500 mN/m to near zero). Furthermore, this method requires only a very modest potential (< 1 V) applied relative to a counter electrode. The resulting change in tension is due primarily to the electrochemical deposition of a surface oxide layer, which acts as a surfactant; removal of the oxide increases the interfacial tension, and vice versa. This technique can be applied in a wide variety of electrolytes and is independent of the substrate on which it rests.

  8. Electronic structure of metallic liquid Se-Te alloys

    NASA Astrophysics Data System (ADS)

    Kao, Shaw Shya; Cutler, Melvin

    1988-06-01

    Experimental data for the electrical conductivity σ, the thermopower S, and the magnetic susceptibility χ are analyzed for alloys SexTe100-x in the metallic and near-metallic range of compositions x=0 to 50. Comparison of the behavior of σ and S in the region where the metallic approximation to the transport coefficients is valid shows that σ(EF) is proportional to the Fermi energy EF for x=10 and 20. In view of the validity of the diffusive model for transport, this corresponds to a parabolic density of states N(EF). At x=30, it is found that N(EF) changes to a linear dependence on EF, in keeping with the beginning of band tailing as the Fermi energy approaches the edge of the valence band. For x<=30, the experimental behavior of the paramagnetic susceptibility χP confirms independently the shape of N(EF) deduced from σ and S, and comparison of the three experimental variables yields numerical values for the band parameters. At x=40 and 50, where analysis requires the use of Fermi-Dirac integrals, the behavior of σ and S is still consistent with a linear N(E), but the behavior of the experimental χP indicates that the spin states are separating from the valence band as the temperature is decreased.

  9. Turbulent Convection in a Rotating Sphere Filled With Liquid Metal

    NASA Astrophysics Data System (ADS)

    Nataf, H.; Aubert, J.; Cardin, P.; Brito, D.; Masson, J.

    2001-12-01

    Understanding the organization of turbulent convective motions in a rotating sphere would help building more realistic models of the geodynamo and solar dynamo. We have performed laboratory experiments using water and gallium as working fluids. We have examined the convective structures that form by following the time--variation of velocity profiles measured by Doppler ultrasonic velocimetry and investigated their dynamical behaviour by monitoring the amplitude of velocity as a function of the Prandtl, Rayleigh and Ekman numbers. Our most striking result is that a strong zonal flow develops in liquid gallium (Prandtl number of 0.025). It can be 2.5 times stronger than typical convective velocities. We explain this phenomenon by the high Reynolds numbers reached in these experiments, up to 2000, much larger than in the water experiments (less than 250). Our observations for gallium are well accounted for by a quasi--geostrophic inertial model, in which kinetic energy is injected at the convective scale and cascades up to a large zonal flow, whose amplitude is limited by friction on the outer sphere. This model predicts that the convective velocity U becomes independent of the two diffusivities (viscous and thermal) and scales as : $ U ~ D Ω ( (α g Q)/(ρ CP Ω 3 D2) )2/5 where D is the thickness of the liquid shell, \\Omega the rotation rate, Q the heat flux, g the gravity acceleration, and \\alpha, \\rho and C_P$ are the thermal expansion coefficient, the density and the heat capacity of the liquid. The sphericity also introduces a variation of velocity with radius. Both the scaling law and these radial variations are in very good agreement with the measured velocity profiles. In contrast, the zonal velocity does depend upon the viscosity of the liquid through friction on the outer boundary. This behaviour illustrates the crucial role of the spherical boundaries in controlling the organization of turbulence. Nevertheless, the motions remain essentially two

  10. Electromagnetic Pumps for Liquid Metal-Fed Electric Thrusters

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.; Markusic, Thomas E.

    2007-01-01

    Prototype designs of two separate pumps for use in electric propulsion systems with liquid lithium and bismuth propellants are presented. Both pumps are required to operate at elevated temperatures, and the lithium pump must additionally withstand the corrosive nature of the propellant. Compatibility of the pump materials and seals with lithium and bismuth were demonstrated through proof-of-concept experiments followed by post-experiment visual inspections. The pressure rise produced by the bismuth pump was found to be linear with input current and ranged from 0-9 kPa for corresponding input current levels of 0-30 A, showing good quantitative agreement with theoretical analysis.

  11. Recycling of rare earth metals from rare earth-transition metal alloy scrap by liquid metal extraction

    DOEpatents

    Ellis, Timothy W.; Schmidt, Frederick A.

    1995-08-01

    Method of treating rare earth metal-bearing scrap, waste or other material (e.g. Nd--Fe--B or Dy--Tb--Fe scrap) to recover the rare earth metal comprising melting the rare earth metal-bearing material, melting a Group IIA metal extractant, such as Mg, Ca, or Ba, in which the rare earth is soluble in the molten state, and contacting the melted material and melted extractant at a temperature and for a time effective to extract the rare earth from the melted material into the melted extractant. The rare earth metal is separated from the extractant metal by vacuum sublimation or distillation.

  12. Recycling of rare earth metals from rare earth-transition metal alloy scrap by liquid metal extraction

    DOEpatents

    Ellis, T.W.; Schmidt, F.A.

    1995-08-01

    A method is described for treating rare earth metal-bearing scrap, waste or other material (e.g. Nd--Fe--B or Dy--Tb--Fe scrap) to recover the rare earth metal comprising melting the rare earth metal-bearing material, melting a Group IIA metal extractant, such as Mg, Ca, or Ba, in which the rare earth is soluble in the molten state, and contacting the melted material and melted extractant at a temperature and for a time effective to extract the rare earth from the melted material into the melted extractant. The rare earth metal is separated from the extractant metal by vacuum sublimation or distillation. 2 figs.

  13. Utilizing Metalized Fabrics for Liquid and Rip Detection and Localization

    SciTech Connect

    Holland, Stephen; Mahan, Cody; Kuhn, Michael J; Rowe, Nathan C

    2013-01-01

    This paper proposes a novel technique for utilizing conductive textiles as a distributed sensor for detecting and localizing liquids (e.g., blood), rips (e.g., bullet holes), and potentially biosignals. The proposed technique is verified through both simulation and experimental measurements. Circuit theory is utilized to depict conductive fabric as a bounded, near-infinite grid of resistors. Solutions to the well-known infinite resistance grid problem are used to confirm the accuracy and validity of this modeling approach. Simulations allow for discontinuities to be placed within the resistor matrix to illustrate the effects of bullet holes within the fabric. A real-time experimental system was developed that uses a multiplexed Wheatstone bridge approach to reconstruct the resistor grid across the conductive fabric and detect liquids and rips. The resistor grid model is validated through a comparison of simulated and experimental results. Results suggest accuracy proportional to the electrode spacing in determining the presence and location of discontinuities in conductive fabric samples. Future work is focused on refining the experimental system to provide more accuracy in detecting and localizing events as well as developing a complete prototype that can be deployed for field testing. Potential applications include intelligent clothing, flexible, lightweight sensing systems, and combat wound detection.

  14. Utilizing metalized fabrics for liquid and rip detection and localization

    NASA Astrophysics Data System (ADS)

    Holland, Stephen A.; Mahan, Cody A.; Kuhn, Michael J.; Rowe, Nathan C.

    2013-05-01

    This paper proposes a novel technique for utilizing electrically conductive textiles as a distributed sensor for detecting and localizing liquids (e.g., blood), damage (e.g., rips, cuts, bullet holes) and, potentially, biosignals. The proposed technique is verified through both simulation and experimental measurements. Circuit theory is employed to depict conductive fabric as a bounded, near-infinite grid of resistors. Solutions to the well-known infinite resistance grid problem are used to confirm the accuracy and validity of this modeling approach. Simulations allow for discontinuities to be placed within the resistor matrix to illustrate the effects of bullet holes within the fabric. A real-time experimental system was developed that uses a multiplexed, Wheatstone bridge measurement approach to determine the resistances of a coarse electrode grid across the conductive fabric. Non-uniform resistance values of the grid infer the presence of liquids and rips in the fabric. The resistor-grid model is validated through a comparison of simulated and experimental results. Results suggest accuracy proportional to the electrode spacing in determining the presence and location of disturbances in conductive fabric samples. Future work is focused on refining the experimental system to provide more accuracy in detecting and localizing events (although just the knowledge of a penetration may be adequate for some intended applications) as well as developing a complete prototype that can be deployed for field testing. Potential applications include intelligent clothing, flexible, lightweight sensing systems, and combat wound detection.

  15. Carbyne fiber synthesis within evaporating metallic liquid carbon

    SciTech Connect

    Cannella, Christopher B.; Goldman, Nir

    2015-07-09

    Carbyne (e.g., linear chains of sp-bonded carbon) has been the subject of intense research focus due to its presence in astrophysical bodies, as well as its potential for use as a nanoelectronic device and superhard material. In this work, we discuss the formation of carbyne fiber bundles over a nanosecond time scale in laser pulse melting studies, using a previously determined density functional tight binding model for carbon coupled with a new correction for the dispersion energy. We determine our dispersion energy model by optimizing a modified Lennard-Jones potential to an experimentally determined equation of state for graphite, yielding excellent results for the bulk modulus and density under ambient conditions. We then simulate previous experiments by heating graphite to high temperature, followed by expanding the ensuing liquid phase to low density. Our results indicate that the initial, hot liquid phase mainly consists of sp2-bonded carbon atoms, which form a system of sp-bonded strands bound together via dispersion interactions upon achieving low density and temperature. Lastly, the high computational efficiency of our approach allows for direct comparison with experiments that span a wide range of thermodynamic conditions and can help determine parameters for synthesis of carbon-based materials with potentially exotic properties.

  16. Carbyne fiber synthesis within evaporating metallic liquid carbon

    DOE PAGES

    Cannella, Christopher B.; Goldman, Nir

    2015-07-09

    Carbyne (e.g., linear chains of sp-bonded carbon) has been the subject of intense research focus due to its presence in astrophysical bodies, as well as its potential for use as a nanoelectronic device and superhard material. In this work, we discuss the formation of carbyne fiber bundles over a nanosecond time scale in laser pulse melting studies, using a previously determined density functional tight binding model for carbon coupled with a new correction for the dispersion energy. We determine our dispersion energy model by optimizing a modified Lennard-Jones potential to an experimentally determined equation of state for graphite, yielding excellentmore » results for the bulk modulus and density under ambient conditions. We then simulate previous experiments by heating graphite to high temperature, followed by expanding the ensuing liquid phase to low density. Our results indicate that the initial, hot liquid phase mainly consists of sp2-bonded carbon atoms, which form a system of sp-bonded strands bound together via dispersion interactions upon achieving low density and temperature. Lastly, the high computational efficiency of our approach allows for direct comparison with experiments that span a wide range of thermodynamic conditions and can help determine parameters for synthesis of carbon-based materials with potentially exotic properties.« less

  17. Non-Fermi liquid phase in metallic Skyrmion crystals

    NASA Astrophysics Data System (ADS)

    Watanabe, Haruki; Parameswaran, Siddharth; Raghu, Srinivas; Vishwanath, Ashvin

    2014-03-01

    Motivated by reports of a non-Fermi liquid state in MnSi, we examine the effect of coupling phonons of an incommensurate skyrmion crystal (SkX) to conduction electrons. We find that non-Fermi liquid behavior emerges in both two and three dimensions over the entire phase, due to an anomalous electron-phonon coupling that is linked to the net skyrmion density. A small parameter, the spiral wave vector in lattice units, allows us to exercise analytic control and ignore Landau damping of phonons over a wide energy range. At the lowest energy scales the problem is similar to electrons coupled to a gauge field. The best prospects for realizing these effects is in short period skyrmion lattice systems such as MnGe or epitaxial MnSi films. We also compare our results with the unusual T 3 / 2 scaling of temperature dependent resistivity seen in high pressure experiments on MnSi. We acknowledge support from the NSF via Grant DMR-0645691, the DOE Office of Basic Energy Sciences via contract DE-AC02-76SF00515, and the Simons, Templeton, and Alfred P. Sloan Foundations.

  18. EFFECT OF LIQUID TO SOLID RATIO ON LEACHING OF METALS FROM MINERAL PROCESSING WASTE

    EPA Science Inventory

    Various anthropogenic activities generate hazardous solid wastes that are affluent in heavy metals, which can cause significant damage to the environment an human health. A mineral processing waste was used to study the effect of liquid to solid ratio (L/S) on the leaching behav...

  19. DEMONSTRATION OF A LIQUID CARBON DIOXIDE PROCESS FOR CLEANING METAL PARTS

    EPA Science Inventory

    The report gives results of a demonstration of liquid carbon dioxide (LCO2) as an alternative to chlorinated solvents for cleaning metal parts. It describes the LCO2 process, the parts tested, the contaminants removed, and results from preliminary laboratory testing and on-site d...

  20. Liquid metal extraction of Nd from NdFeB magnet scrap

    SciTech Connect

    Xu, Yanchen

    1999-12-10

    This research involves using molten magnesium (Mg) to remove neodymium (Nd) from NdFeB magnet scrap by diffusion. The results show that liquid metal extraction of Nd may be a viable and inexpensive method for recovering the expensive rare earth element Nd for use in Mg castings.

  1. Investigation of Liquid Metal Heat Exchanger Designs for Fission Surface Power

    NASA Technical Reports Server (NTRS)

    Dyson, Rodger W.; Penswick, Barry; Robbie, Malcolm; Geng, Steven M.

    2009-01-01

    Fission surface power is an option for future Moon and Mars surface missions. High power nuclear reactor heated Stirling convertors are an option to provide reliable power for long duration outpost operations. This report investigates various design approaches for the liquid metal to acceptor heat exchange and clarifies the details used in the analysis.

  2. Subtask 12E1: Compatibility of structural materials in liquid alkali metals

    SciTech Connect

    Natesan, K.; Rink, D.L.; Haglund, R.; Clark, R.W.

    1995-03-01

    The objectives of this task are to (a) evaluate the chemical compatibility of structural alloys such as V-5 wt.%Cr-5 wt.%Ti alloy and Type 316 stainless steel for application in liquid alkali metals such as lithium and sodium-78 wt.% potassium (NaK) at temperatures that are in the range of interest for the International Thermonuclear Experimental Reactor (ITER); (b) evaluate the transfer of nonmetallic elements such as oxygen, nitrogen, carbon, and hydrogen between structural materials and liquid metals; and (c) evaluate the effects of such transfers on the mechanical and microstructural characteristics of the materials for long-term service in liquid-metal environments. Candidate structural materials are being evaluated for their compatibility, interstitial-element transfer, and corrosion in liquid alkali-metal systems such as lithium and NaK. Type 316 stainless steel and V-5Cr-5Ti coupon specimens with and without prealuminizing treatment have been exposed to NaK and lithium environments of commercial purity for times up to 3768 h at temperatures between 300 and 400{degrees}C. 13 refs., 8 figs., 3 tabs.

  3. Refolding of horseradish peroxidase is enhanced in presence of metal cofactors and ionic liquids.

    PubMed

    Bae, Sang-Woo; Eom, Doyoung; Mai, Ngoc Lan; Koo, Yoon-Mo

    2016-03-01

    The effects of various refolding additives, including metal cofactors, organic co-solvents, and ionic liquids, on the refolding of horseradish peroxidase (HRP), a well-known hemoprotein containing four disulfide bonds and two different types of metal centers, a ferrous ion-containing heme group and two calcium atoms, which provide a stabilizing effect on protein structure and function, were investigated. Both metal cofactors (Ca(2+) and hemin) and ionic liquids have positive impact on the refolding of HRP. For instance, the HRP refolding yield remarkably increased by over 3-fold upon addition of hemin and calcium chloride to the refolding buffer as compared to that in the conventional urea-containing refolding buffer. Moreover, the addition of ionic liquids [EMIM][Cl] to the hemin and calcium cofactor-containing refolding buffer further enhanced the HRP refolding yield up to 80% as compared to 12% in conventional refolding buffer at relatively high initial protein concentration (5 mg/ml). These results indicated that refolding method utilizing metal cofactors and ionic liquids could enhance the yield and efficiency for metalloprotein.

  4. Bellows-Type Accumulators for Liquid Metal Loops of Space Reactor Power Systems

    SciTech Connect

    Tournier, Jean-Michel; El-Genk, Mohamed S.

    2006-01-20

    In many space nuclear power systems, the primary and/or secondary loops use liquid metal working fluids, and require accumulators to accommodate the change in the liquid metal volume and maintain sufficient subcooling to avoid boiling. This paper developed redundant and light-weight bellows-type accumulators with and without a mechanical spring, and compared the operating condition and mass of the accumulators for different types of liquid metal working fluids and operating temperatures: potassium, NaK-78, sodium and lithium loops of a total capacity of 50 liters and nominal operating temperatures of 840 K, 860 K, 950 K and 1340 K, respectively. The effects of using a mechanical spring and different structural materials on the design, operation and mass of the accumulators are also investigated. The structure materials considered include SS-316, Hastelloy-X, C-103 and Mo-14Re. The accumulator without a mechanical spring weighs 23 kg and 40 kg for a coolant subcooling of 50 K and 100 K, respectively, following a loss of the fill gas. The addition of a mechanical spring comes with a mass penalty, in favor of higher redundancy and maintaining a higher liquid metal subcooling.

  5. Bellows-Type Accumulators for Liquid Metal Loops of Space Reactor Power Systems

    NASA Astrophysics Data System (ADS)

    Tournier, Jean-Michel; El-Genk, Mohamed S.

    2006-01-01

    In many space nuclear power systems, the primary and/or secondary loops use liquid metal working fluids, and require accumulators to accommodate the change in the liquid metal volume and maintain sufficient subcooling to avoid boiling. This paper developed redundant and light-weight bellows-type accumulators with and without a mechanical spring, and compared the operating condition and mass of the accumulators for different types of liquid metal working fluids and operating temperatures: potassium, NaK-78, sodium and lithium loops of a total capacity of 50 liters and nominal operating temperatures of 840 K, 860 K, 950 K and 1340 K, respectively. The effects of using a mechanical spring and different structural materials on the design, operation and mass of the accumulators are also investigated. The structure materials considered include SS-316, Hastelloy-X, C-103 and Mo-14Re. The accumulator without a mechanical spring weighs 23 kg and 40 kg for a coolant subcooling of 50 K and 100 K, respectively, following a loss of the fill gas. The addition of a mechanical spring comes with a mass penalty, in favor of higher redundancy and maintaining a higher liquid metal subcooling.

  6. The liquid metal slip ring experiment for the communications technology satellite

    NASA Technical Reports Server (NTRS)

    Lovell, R. R.

    1972-01-01

    The experiment is designed to demonstrate liquid metal slip ring (LMSR) performance in a space environment. An evaluation was made of the features of the LMSR where improvement in performance over conventional slip rings was expected. The primary measurements to be made in the experiment will allow a determination of the slip ring electrical resistance, between ring insulation and ring cleanliness.

  7. Nuclear Engineering Computer Modules, Thermal-Hydraulics, TH-2: Liquid Metal Fast Breeder Reactors.

    ERIC Educational Resources Information Center

    Reihman, Thomas C.

    This learning module is concerned with the temperature field, the heat transfer rates, and the coolant pressure drop in typical liquid metal fast breeder reactor (LMFBR) fuel assemblies. As in all of the modules of this series, emphasis is placed on developing the theory and demonstrating the use with a simplified model. The heart of the module is…

  8. Method for passive cooling liquid metal cooled nuclear reactors, and system thereof

    DOEpatents

    Hunsbedt, Anstein; Busboom, Herbert J.

    1991-01-01

    A liquid metal cooled nuclear reactor having a passive cooling system for removing residual heat resulting from fuel decay during reactor shutdown. The passive cooling system comprises a plurality of partitions surrounding the reactor vessel in spaced apart relation forming intermediate areas for circulating heat transferring fluid which remove and carry away heat from the reactor vessel.

  9. Instability of the Liquid Metal-Pattern Interface in the Lost Foam Casting of Aluminum Alloys

    NASA Astrophysics Data System (ADS)

    Griffiths, W. D.; Ainsworth, M. J.

    2016-06-01

    The nature of the liquid metal-pattern interface during mold filling in the Lost Foam casting of aluminum alloys was investigated using real-time X-ray radiography for both normal expanded polystyrene, and brominated polystyrene foam patterns. Filling the pattern under the action of gravity from above or below had little effect on properties, both cases resulting in a large scatter of tensile strength values, (quantified by their Weibull Modulus). Countergravity filling at different velocities demonstrated that the least scatter of tensile strength values (highest Weibull Modulus) was associated with the slowest filling, when a planar liquid metal-pattern interface occurred. Real-time X-ray radiography showed that the advancing liquid metal front became unstable above a certain critical velocity, leading to the entrainment of the degrading pattern material and associated defects. It has been suggested that the transition of the advancing liquid metal-pattern interface into an unstable regime may be a result of Saffman-Taylor Instability.

  10. Hartmann flow with temperature-dependent physical properties. [magnetohydrodynamics of liquid metal

    NASA Technical Reports Server (NTRS)

    Linn, G. T.; Walker, J. S.

    1978-01-01

    Attention is given to the steady, fully developed, one-dimensional flow of a liquid metal in which thermal conductivity, electrical conductivity, and viscosity are functions of temperature. It is found that the properties are decreasing functions of temperature and the first differences between temperature-dependent and constant properties are discussed.

  11. An energetic evaluation of dissolution corrosion capabilities of liquid metals on iron surface.

    PubMed

    Xu, Yichun; Song, Chi; Zhang, Yange; Liu, C S; Pan, B C; Wang, Zhiguang

    2014-08-21

    Using first principles calculations, dissolution corrosion of liquid metals on iron surfaces has been investigated by calculating adsorption energies of metal atoms in the liquid phase on the surface and escape energies of surface Fe atoms. The adsorption energies, characterizing the stability of the adsorbed atoms on the investigated surfaces, show that Bi is more stable than Pb and Au. The escape energies, representing the energy required for an Fe atom to escape from the surface, show that adsorbed Pb makes surface Fe atoms escape more easily than Bi and Au. The combination of adsorption energy and escape energy indicates that the corrosion capabilities of liquid metals decrease in the order Bi > Pb > Au. This is further proved by the investigation of surface properties, such as inter-layer distance, magnetic momentum and charge density difference. The results are consistent with experimental results that Fe can be corroded more severely in Bi than in Pb. In the case of liquid alloys, chemical proportions of compositions are incorporated to evaluate the corrosion capabilities of Pb-Bi eutectic (LBE) and Pb-Au eutectic (LGE). It is found that LBE has more severe corrosion capability than LGE. The energetic calculation is further developed in evaluating the effect of alloying elements in popular steels on the dissolution corrosion. The results indicate that Si, V, Nb and Mo may mitigate the dissolution corrosion of martensite steels in liquid Pb, Bi and Au.

  12. Heat-driven liquid metal cooling device for the thermal management of a computer chip

    NASA Astrophysics Data System (ADS)

    Ma, Kun-Quan; Liu, Jing

    2007-08-01

    The tremendous heat generated in a computer chip or very large scale integrated circuit raises many challenging issues to be solved. Recently, liquid metal with a low melting point was established as the most conductive coolant for efficiently cooling the computer chip. Here, by making full use of the double merits of the liquid metal, i.e. superior heat transfer performance and electromagnetically drivable ability, we demonstrate for the first time the liquid-cooling concept for the thermal management of a computer chip using waste heat to power the thermoelectric generator (TEG) and thus the flow of the liquid metal. Such a device consumes no external net energy, which warrants it a self-supporting and completely silent liquid-cooling module. Experiments on devices driven by one or two stage TEGs indicate that a dramatic temperature drop on the simulating chip has been realized without the aid of any fans. The higher the heat load, the larger will be the temperature decrease caused by the cooling device. Further, the two TEGs will generate a larger current if a copper plate is sandwiched between them to enhance heat dissipation there. This new method is expected to be significant in future thermal management of a desk or notebook computer, where both efficient cooling and extremely low energy consumption are of major concern.

  13. Electromagnetic induction pump for pumping liquid metals and other conductive liquids

    DOEpatents

    Smither, R.K.

    1993-05-11

    An electromagnetic induction pump is described in which an electrically conductive liquid is made to flow by means of a force created by interaction of a permanent magnetic field and a DC current. The pump achieves high efficiency through combination of: powerful permanent magnet materials which provide a high strength field that is uniform and constant; steel tubing formed into a coil which is constructed to carry conducting liquids with minimal electrical resistance and heat; and application of a voltage to induce a DC current which continuously produces a force in the direction of the desired flow.

  14. Electromagnetic induction pump for pumping liquid metals and other conductive liquids

    DOEpatents

    Smither, Robert K.

    1993-01-01

    An electromagnetic induction pump in which an electrically conductive liquid is made to flow by means of a force created by interaction of a permanent magnetic field and a DC current. The pump achieves high efficiency through combination of: powerful permanent magnet materials which provide a high strength field that is uniform and constant; steel tubing formed into a coil which is constructed to carry conducting liquids with minimal electrical resistance and heat; and application of a voltage to induce a DC current which continuously produces a force in the direction of the desired flow.

  15. Universal Scaling Law for Atomic Diffusion and Viscosity in Liquid Metals

    NASA Astrophysics Data System (ADS)

    Li, Guang-Xu; Liu, Chang-Song; Zhu, Zhen-Gang

    2004-12-01

    The recently proposed scaling law relating the diffusion coefficient and the excess entropy of liquid [Samanta A et al. 2004 Phys. Rev. Lett. 92 145901; Dzugutov M 1996 Nature 381 137], and a quasi-universal relationship between the transport coefficients and excess entropy of dense fluids [Rosenfeld Y 1977 Phys. Rev. A 15 2545], are tested for diverse liquid metals using molecular dynamics simulations. Interatomic potentials derived from the glue potential and second-moment approximation of tight-binding scheme are used to study liquid metals. Our simulation results give sound support to the above-mentioned universal scaling laws. Following Dzugutov, we have also reached a new universal scaling relationship between the viscosity coefficient and excess entropy. The simulation results suggest that the reduced transport coefficients can be expressed approximately in terms of the corresponding packing density.

  16. High-Temperature Liquid Metal Infusion Considering Surface Tension-Viscosity Dissipation

    NASA Astrophysics Data System (ADS)

    Kumar, Vinod; Harris, Christopher K.; Bronson, Arturo; Shantha-Kumar, Sanjay; Medina, Arturo

    2016-02-01

    In considering the significant effect of the surface tension-viscosity dissipation driving the fluid flow within a capillary, high-temperature liquid metal infusion was analyzed for titanium, yttrium, hafnium, and zirconium penetrating into a packed bed. A model of the dissipation considers the momentum balance within the capillary to determine the rate of infusion, which is compared with the Semlak-Rhines model developed for liquid metal penetration into a packed bed assumed as a bundle of tubes mimicking the porosity of a packed bed. For liquid Ti, the penetration rate was calculated from 0.2 µs to 1 ms and rose to a maximum of 7 m/s at approximately 1 µs; after which, the rate decreased to 0.7 m/s at 1 ms. Beyond 10 µs, the decreasing trend of the rate of penetration determined by the model of dissipation compared favorably with the Semlak-Rhines equation.

  17. Enhancement of heat removal using concave liquid metal targets for high-power accelerators.

    SciTech Connect

    Konkashbaev, I.; Fischer, P.; Hassanein, A.; Mokhov, N. V.; Mathematics and Computer Science; FNAL

    2007-01-01

    The need is increasing for development of high-power targets and beam dump areas for the production of intense beams of secondary particles. The severe constraints arising from a megawatt beam deposited on targets and absorbers call for nontrivial procedures to dilute the beam. This study describes the development of targets and absorbers and the advantages of using flowing liquid metal in concave channels first proposed by IFMIF to raise the liquid metal boiling point by increasing the pressure in liquid supported by a centrifugal force. Such flow with a back-wall is subject to Taylor-Couette instability. The instability can play a positive role of increasing the heat transfer from the hottest region in the target/absorber to the back-wall cooled by water. Results of theoretical analysis and numerical modeling of both targets and dump areas for the IFMIF, ILC, and RIA facilities are presented.

  18. Calculations of electrical transport properties of liquid metals at high pressures

    NASA Technical Reports Server (NTRS)

    Evans, R.; Jain, A.

    1972-01-01

    It is shown how the usual nearly-free-electron model for the electrical resistivity of simple liquid metals can be extended to the case of liquid transition metals such as iron. A simple prescription is given for calculating the resistivity at different densities and temperatures. As an application and example of the method, calculations on liquid iron at different densities were carried out and the resistivity of molten iron in the earth's outer core is estimated. The effects of alloying iron with other elements are also considered. The calculated conductivity of the outer core is well within the limit required for the dynamo model of the geomagnetic field and agrees well with some recent shock wave data.

  19. 3-D printing of liquid metals for stretchable and flexible conductors

    NASA Astrophysics Data System (ADS)

    Trlica, Chris; Parekh, Dishit Paresh; Panich, Lazar; Ladd, Collin; Dickey, Michael D.

    2014-06-01

    3-D printing is an emerging technology that has been used primarily on small scales for rapid prototyping, but which could also herald a wider movement towards decentralized, highly customizable manufacturing. Polymers are the most common materials to be 3-D printed today, but there is great demand for a way to easily print metals. Existing techniques for 3-D printing metals tend to be expensive and energy-intensive, and usually require high temperatures or pressures, making them incompatible with polymers, organics, soft materials, and biological materials. Here, we describe room temperature liquid metals as complements to polymers for 3-D printing applications. These metals enable the fabrication of soft, flexible, and stretchable devices. We survey potential room temperature liquid metal candidates and describe the benefits of gallium and its alloys for these purposes. We demonstrate the direct printing of a liquid gallium alloy in both 2-D and 3-D and highlight the structures and shapes that can be fabricated using these processes.

  20. Superconducting homopolar machinery - Liquid metal current collection and design principles

    NASA Astrophysics Data System (ADS)

    Eriksson, J.-T.

    The current collection problem of superconducting homopolar machines is treated. Auxiliary rotors at each end of the armature winding provide full torque at zero speed; the velocity dividing effect of this arrangement decreases collector losses by about a factor of 2.5 compared to conventional designs. Porous electrode surfaces made from spun tungsten wire are used, and experiments showed that as a cover liquid, oxalic acid provides excellent reducing properties. Adding 0.2 M sodium perchlorate suppresses the emulsification tendency. The ejection instability is phenomenologically explained using Kelvin-Helmholtz concepts, and is experimentally supported. The design procedure for superconducting homopolar machines is presented, offering a practical working tool for rough estimation of losses, efficiency, adequate number of armature current loops and the required amount of superconducting wire. The algorithm provides a convenient way of investigating parameter interconnections.

  1. Solid-liquid-vapor metal-catalyzed etching of lateral and vertical nanopores.

    PubMed

    Wallentin, Jesper; Deppert, Knut; Borgström, Magnus T

    2013-10-18

    Etching is an essential tool for the creation of nanostructures, where patterned metal structures can be used as masks. Here, we investigate HCl gas etching of InP substrates decorated with Au nanoparticles, and find that the etch rate is strongly increased at the Au-InP interfaces. The {111}A facets of the InP are preferentially etched. The metal nanoparticles follow in the etch direction, thereby creating nanopores. The size and position of the pores is controlled by the Au nanoparticles, and we measure nanopores as thin as 20 nm with an aspect ratio of 25:1. The direction of the nanopores is influenced by the temperature and the substrate orientation, which we use to demonstrate lateral, vertical and inclined nanopores. We explain the process by a solid-liquid-vapor model, in which the liquid metal particle catalyzes the dissolution of the solid InP. PMID:24060650

  2. Instability of nano- and microscale liquid metal filaments: Transition from single droplet collapse to multidroplet breakup

    SciTech Connect

    Hartnett, Chris A.; Mahady, Kyle; Fowlkes, Jason Davidson; Afkhami, Shahriar; Rack, P. D.; Kondic, L.

    2015-11-23

    We carry out experimental and numerical studies to investigate the collapse and breakup of finite size, nano- and microscale, liquid metal filaments supported on a substrate. We find the critical dimensions below which filaments do not break up but rather collapse to a single droplet. The transition from collapse to breakup can be described as a competition between two fluid dynamic phenomena: the capillary driven end retraction and the Rayleigh–Plateau type instability mechanism that drives the breakup. We focus on the unique spatial and temporal transition region between these two phenomena using patterned metallic thin film strips and pulsed-laser-induced dewetting. The experimental results are compared to an analytical model proposed by Driessen et al. and modified to include substrate interactions. Additionally, we report the results of numerical simulations based on a volume-of-fluid method to provide additional insight and highlight the importance of liquid metal resolidification, which reduces inertial effects.

  3. Direct observation of an abrupt insulator-to-metal transition in dense liquid deuterium

    NASA Astrophysics Data System (ADS)

    Knudson, M. D.; Desjarlais, M. P.; Becker, A.; Lemke, R. W.; Cochrane, K. R.; Savage, M. E.; Bliss, D. E.; Mattsson, T. R.; Redmer, R.

    2015-06-01

    Eighty years ago, it was proposed that solid hydrogen would become metallic at sufficiently high density. Despite numerous investigations, this transition has not yet been experimentally observed. More recently, there has been much interest in the analog of this predicted metallic transition in the dense liquid, due to its relevance to planetary science. Here, we show direct observation of an abrupt insulator-to-metal transition in dense liquid deuterium. Experimental determination of the location of this transition provides a much-needed benchmark for theory and may constrain the region of hydrogen-helium immiscibility and the boundary-layer pressure in standard models of the internal structure of gas-giant planets.

  4. Homochiral metal-organic framework used as a stationary phase for high-performance liquid chromatography.

    PubMed

    Kong, Jiao; Zhang, Mei; Duan, Ai-Hong; Zhang, Jun-Hui; Yang, Rui; Yuan, Li-Ming

    2015-02-01

    Metal-organic frameworks are promising porous materials. Chiral metal-organic frameworks have attracted considerable attention in controlling enantioselectivity. In this study, a homochiral metal-organic framework [Co(2) (D-cam)(2) (TMDPy)] (D-cam = D-camphorates, TMDPy = 4,4'-trimethylenedipyridine) with a non-interpenetrating primitive cubic net has been used as a chiral stationary phase in high-performance liquid chromatography. It has allowed the successful separation of six positional isomers and six chiral compounds. The good selectivity and baseline separation, or at least 60% valley separation, confirmed its excellent molecular recognition characteristics. The relative standard deviations for the retention time of run-to-run and column-to-column were less than 1.8 and 3.1%, respectively. These results demonstrate that [Co(2) (D-cam)(2) (TMDPy)] may represent a promising chiral stationary phase for use in high-performance liquid chromatography.

  5. EXAFS study into the speciation of metal salts dissolved in ionic liquids and deep eutectic solvents.

    PubMed

    Hartley, Jennifer M; Ip, Chung-Man; Forrest, Gregory C H; Singh, Kuldip; Gurman, Stephen J; Ryder, Karl S; Abbott, Andrew P; Frisch, Gero

    2014-06-16

    The speciation of metals in solution controls their reactivity, and this is extremely pertinent in the area of metal salts dissolved in ionic liquids. In the current study, the speciation of 25 metal salts is investigated in four deep eutectic solvents (DESs) and five imidazolium-based ionic liquids using extended X-ray absorption fine structure. It is shown that in diol-based DESs M(I) ions form [MCl2](-) and [MCl3](2-) complexes, while all M(II) ions form [MCl4](2-) complexes, with the exception of Ni(II), which exhibits a very unusual coordination by glycol molecules. This was also found in the X-ray crystal structure of the compound [Ni(phen)2(eg)]Cl2·2eg (eg = ethylene glycol). In a urea-based DES, either pure chloro or chloro-oxo coordination is observed. In [C6mim][Cl] pure chloro complexation is also observed, but coordination numbers are smaller (typically 3), which can be explained by the long alkyl chain of the cation. In [C2mim][SCN] metal ions are entirely coordinated by thiocyanate, either through the N or the S atom, depending on the hardness of the metal ion according to the hard-soft acid-base principle. With weaker coordinating anions, mixed coordination between solvent and solute anions is observed. The effect of hydrate or added water on speciation is insignificant for the diol-based DESs and small in other liquids with intermediate or strong ligands. One of the main findings of this study is that, with respect to metal speciation, there is no fundamental difference between deep eutectic solvents and classic ionic liquids. PMID:24897923

  6. Tomonaga-Luttinger liquid theory for metallic fullurene polymers

    NASA Astrophysics Data System (ADS)

    Yoshioka, Hideo; Shima, Hiroyuki; Noda, Yusuke; Ono, Shota; Ohno, Kaoru

    2016-04-01

    We investigate the low energy behavior of local density of states in metallic C60 polymers theoretically. The multichannel bosonization method is applied to electronic band structures evaluated from first-principles calculation, by which the effects of electronic correlation and nanoscale corrugation in the atomic configuration are fully taken into account. We obtain a closed-form expression for the power-law anomalies in the local density of states, which successfully describes the experimental observation on the C60 polymers in a quantitative manner. An important implication from the closed-form solution is the existence of an experimentally unobserved crossover at nearly a hundred milli-electron volts, beyond which the power-law exponent of the C60 polymers should change significantly.

  7. Microscopic Motion of Liquid Metal Plasma Facing Components In A Diverted Plasma

    SciTech Connect

    Jaworski, M A; Morley, N B; Abrams, T; Kaita, R; Kallman, J; Kugel, H; Majeski, R

    2010-09-22

    Liquid metal plasma facing components (PFCs) have been identified as an alternative material for fusion plasma experiments. The use of a liquid conductor where significant magnetic fields are present is considered risky, with the possibility of macroscopic fluid motion and possible ejection into the plasma core. Analysis is carried out on thermoelectric magnetohydrodynamic (TEMHD) forces caused by temperature gradients in the liquid-container system itself in addition to scrape-off-layer currents interacting with the PFC from a diverted plasma. Capillary effects at the liquid-container interface will be examined which govern droplet ejection criteria. Stability of the interface is determined using linear stability methods. In addition to application to liquidmetal PFCs, thin film liquidmetal effects have application to current and future devices where off-normal events may liquefy portions of the first wall and other plasma facing components.

  8. Descent of low-Bond-number liquid-metal diapirs with trailing conduits during core formation

    NASA Astrophysics Data System (ADS)

    Rains, C.; Weeraratne, D. S.

    2012-12-01

    Formation of the early Earth involved violent impacts and meteorite bombardment which partially or fully melted surface materials, facilitating separation of iron metal from silicates. Geochemical constraints on core formation times indicate that this liquid metal must have been transported to the center of the Earth within 30 Ma. Among the mechanisms that have been proposed, metal-silicate plumes resulting from Rayleigh-Taylor instabilities of a liquid-metal pond at the bottom of a magma ocean provide the fastest rates of delivery to the core. Recent studies have shown that these rapidly descending plumes develop trailing conduits that fill with the overlying melted silicate material. However, while large plumes descend quickly, they do not provide enough time or surface area for metal-silicate equilibration to be achieved throughout the mantle. Instead, small metal drops descending in the wake of larger diapirs or in conduits of their own making may have been crucial in the equilibration process that resulted in the excess siderophile mantle abundance. We investigate the instability and descent of liquid-metal drops through a highly viscous layer using three-component laboratory fluid experiments representing the Earth's proto-mantle (layer 2) covered by a magma ocean (layer 1), and a liquid iron pond (layer 3) initially resting at their interface. Silicate materials are represented by dehydrated (layer 2), or diluted (layer 1) glucose and salt solutions. Liquid gallium represents the iron metal phase. We scale our experiments to the Earth's mantle through the use of Bond numbers to characterize drops and diapirs, and a non-dimensional length scale λ, which we define as the ratio of radius to height, to characterize conduits. Previous laboratory work using liquid gallium has investigated high-Bond-number diapirs (B = 13 - 66) and conduits of λ ~ 0.2, analogous to large plumes in the Earth. Here, we focus on low Bond numbers (B ~ 4), and small λ ~ .05 to

  9. The effect of sulfur on vapor liquid fractionation of metals in hydrothermal systems

    NASA Astrophysics Data System (ADS)

    Pokrovski, Gleb S.; Borisova, Anastassia Yu.; Harrichoury, Jean-Claude

    2008-02-01

    Despite the growing evidence that the vapor phase, formed through magma degassing and ore fluid boiling, can selectively concentrate and transport metals, the effects of major volatile components like sulfur, chlorine or carbon dioxide on the metal vapor-liquid fractionation and vapor-phase transport under magmatic-hydrothermal conditions remain poorly known. We performed systematic experiments to investigate the effect of sulfur ligands on metal vapor-liquid partitioning in model H 2O-S-NaCl-KCl-NaOH systems at temperatures from 350 to 500 °C. Results show that at acidic-to-neutral conditions, vapor-liquid equilibrium distribution coefficients, Km = mvapor / mliquid, where m is the mass concentration of the metal in corresponding phase, of metalloids (As, Sb) and base metals (Zn, Fe, Pb, Ag) are in the range 0.1-1.0 and 0.001-0.1, respectively, and are not significantly affected by the presence of geologically common sulfur concentrations, up to 1-3 wt.% S. In contrast, the partitioning of Cu, Au, and Pt into the vapor increases by a factor of 100 in comparison to the S-free water-salt system, yielding Km values of 0.5-1.0, 1-10, and 10-20, respectively, due to formation of volatile neutral complexes with H 2S and, possibly, SO 2. In neutral-to-basic systems, Zn, Pb, Fe and Ag show 10-100-fold increase of their partition coefficients, whereas Cu, Au and Pt exhibit Km values of up to several orders of magnitude lower, compared to acidic conditions at similar temperature, pressure and sulfur contents. These vapor-liquid distribution patterns result from combined effects of i) formation of volatile species with reduced sulfur ligands in the vapor phase, ii) changes in the metal speciation in the coexisting liquid phase as a function of pH, and iii) solute-solvent interactions in both phases. Our data explain the vapor-liquid fractionation trends for many metals as inferred in coexisting brine and vapor inclusions from magmatic-hydrothermal deposits, and provide a

  10. 3D printing of liquid metals as fugitive inks for fabrication of 3D microfluidic channels.

    PubMed

    Parekh, Dishit P; Ladd, Collin; Panich, Lazar; Moussa, Khalil; Dickey, Michael D

    2016-05-21

    This paper demonstrates a simple method to fabricate 3D microchannels and microvasculature at room temperature by direct-writing liquid metal as a sacrificial template. The formation of a surface oxide skin on the low-viscosity liquid metal stabilizes the shape of the printed metal for planar and out-of-plane structures. The printed structures can be embedded in a variety of soft (e.g. elastomeric) and rigid (e.g. thermoset) polymers. Both acid and electrochemical reduction are capable of removing the oxide skin that forms on the metal, which destabilizes the ink so that it withdraws from the encapsulating material due to capillary forces, resulting in nearly full recovery of the fugitive ink at room temperature. Whereas conventional fabrication procedures typically confine microchannels to 2D planes, the geometry of the printed microchannels can be varied from a simple 2D network to complex 3D architectures without using lithography. The method produces robust monolithic structures without the need for any bonding or assembling techniques that often limit the materials of construction of conventional microchannels. Removing select portions of the metal leaves behind 3D metal features that can be used as antennas, interconnects, or electrodes for interfacing with lab-on-a-chip devices. This paper describes the capabilities and limitations of this simple process. PMID:27025537

  11. Ionomer-Liquid Electrolyte Hybrid Ionic Conductor for High Cycling Stability of Lithium Metal Electrodes

    PubMed Central

    Song, Jongchan; Lee, Hongkyung; Choo, Min-Ju; Park, Jung-Ki; Kim, Hee-Tak

    2015-01-01

    The inhomogeneous Li electrodeposition of lithium metal electrode has been a major impediment to the realization of rechargeable lithium metal batteries. Although single ion conducting ionomers can induce more homogeneous Li electrodeposition by preventing Li+ depletion at Li surface, currently available materials do not allow room-temperature operation due to their low room temperature conductivities. In the paper, we report that a highly conductive ionomer/liquid electrolyte hybrid layer tightly laminated on Li metal electrode can realize stable Li electrodeposition at high current densities up to 10 mA cm−2 and permit room-temperature operation of corresponding Li metal batteries with low polarizations. The hybrid layer is fabricated by laminating few micron-thick Nafion layer on Li metal electrode followed by soaking 1 M LiPF6 EC/DEC (1/1) electrolyte. The Li/Li symmetric cell with the hybrid layer stably operates at a high current density of 10 mA cm−2 for more than 2000 h, which corresponds to more than five-fold enhancement compared with bare Li metal electrode. Also, the prototype Li/LiCoO2 battery with the hybrid layer offers cycling stability more than 350 cycles. These results demonstrate that the hybrid strategy successfully combines the advantages of bi-ionic liquid electrolyte (fast Li+ transport) and single ionic ionomer (prevention of Li+ depletion). PMID:26411701

  12. 3D printing of liquid metals as fugitive inks for fabrication of 3D microfluidic channels.

    PubMed

    Parekh, Dishit P; Ladd, Collin; Panich, Lazar; Moussa, Khalil; Dickey, Michael D

    2016-05-21

    This paper demonstrates a simple method to fabricate 3D microchannels and microvasculature at room temperature by direct-writing liquid metal as a sacrificial template. The formation of a surface oxide skin on the low-viscosity liquid metal stabilizes the shape of the printed metal for planar and out-of-plane structures. The printed structures can be embedded in a variety of soft (e.g. elastomeric) and rigid (e.g. thermoset) polymers. Both acid and electrochemical reduction are capable of removing the oxide skin that forms on the metal, which destabilizes the ink so that it withdraws from the encapsulating material due to capillary forces, resulting in nearly full recovery of the fugitive ink at room temperature. Whereas conventional fabrication procedures typically confine microchannels to 2D planes, the geometry of the printed microchannels can be varied from a simple 2D network to complex 3D architectures without using lithography. The method produces robust monolithic structures without the need for any bonding or assembling techniques that often limit the materials of construction of conventional microchannels. Removing select portions of the metal leaves behind 3D metal features that can be used as antennas, interconnects, or electrodes for interfacing with lab-on-a-chip devices. This paper describes the capabilities and limitations of this simple process.

  13. Conventional and microwave hydrothermal synthesis of monodispersed metal oxide nanoparticles at liquid-liquid interface

    EPA Science Inventory

    Monodispersed nanoparticles of metal oxide including ferrites MFe2O4 (M=, Ni, Co, Mn) and γ-Fe2O3, Ta2O5 etc. have been synthesized using a water-toluene interface under both conventional and microwave hydrothermal conditions. This general synthesis procedure uses readily availab...

  14. Calcium-bismuth electrodes for large-scale energy storage (liquid metal batteries)

    SciTech Connect

    Kim, H; Boysen, DA; Ouchi, T; Sadoway, DR

    2013-11-01

    Calcium is an attractive electrode material for use in grid-scale electrochemical energy storage due to its low electronegativity, earth abundance, and low cost. The feasibility of combining a liquid Ca-Bi positive electrode with a molten salt electrolyte for use in liquid metal batteries at 500-700 degrees C was investigated. Exhibiting excellent reversibility up to current densities of 200 mA cm(-2), the calcium bismuth liquid alloy system is a promising positive electrode candidate for liquid metal batteries. The measurement of low self-discharge current suggests that the solubility of calcium metal in molten salt electrolytes can be sufficiently suppressed to yield high coulombic efficiencies >98%. The mechanisms giving rise to Ca-Bi electrode overpotentials were investigated in terms of associated charge transfer and mass transport resistances. The formation of low density Ca11Bi10 intermetallics at the electrode electrolyte interface limited the calcium deposition rate capability of the electrodes; however, the co-deposition of barium into bismuth from barium-containing molten salts suppressed Ca-Bi intermetallic formation thereby improving the discharge capacity. (C) 2013 Elsevier B.V. All rights reserved.

  15. Calcium-bismuth electrodes for large-scale energy storage (liquid metal batteries)

    NASA Astrophysics Data System (ADS)

    Kim, Hojong; Boysen, Dane A.; Ouchi, Takanari; Sadoway, Donald R.

    2013-11-01

    Calcium is an attractive electrode material for use in grid-scale electrochemical energy storage due to its low electronegativity, earth abundance, and low cost. The feasibility of combining a liquid Ca-Bi positive electrode with a molten salt electrolyte for use in liquid metal batteries at 500-700 °C was investigated. Exhibiting excellent reversibility up to current densities of 200 mA cm-2, the calcium-bismuth liquid alloy system is a promising positive electrode candidate for liquid metal batteries. The measurement of low self-discharge current suggests that the solubility of calcium metal in molten salt electrolytes can be sufficiently suppressed to yield high coulombic efficiencies >98%. The mechanisms giving rise to Ca-Bi electrode overpotentials were investigated in terms of associated charge transfer and mass transport resistances. The formation of low density Ca11Bi10 intermetallics at the electrode-electrolyte interface limited the calcium deposition rate capability of the electrodes; however, the co-deposition of barium into bismuth from barium-containing molten salts suppressed Ca-Bi intermetallic formation thereby improving the discharge capacity.

  16. Levitation of a metallic sphere near gas-liquid and liquid-liquid interfaces by the repulsive Casimir force

    NASA Astrophysics Data System (ADS)

    Inui, Norio

    2014-06-01

    By counteracting gravity, the repulsive Casimir force enables stable levitation of a perfectly conducting particle near a liquid-air interface if the particle exists inside the liquid. In the present study, we examine the levitation of a gold particle near a bromobenzene-air interface and calculate the levitation height using the scattering-matrix formulation. In addition, we consider the Casimir force acting on a gold sphere near the interface between bromobenzene and water. At asymptotically large separations, the Casimir force is attractive because of the large static dielectric permittivity of water. However, the Casimir force changes from attractive to repulsive as the separation decreases. We also found that the gold particle can be levitated in bromobenzene above water.

  17. Surface study of metal-containing ionic liquids by means of photoemission and absorption spectroscopies

    NASA Astrophysics Data System (ADS)

    Caporali, Stefano; Pedio, Maddalena; Chiappe, Cinzia; Pomelli, Christian S.; Acres, Robert G.; Bardi, Ugo

    2016-06-01

    The vacuum/liquid interface of different ionic liquids obtained by dissolving bistriflimide salts of Ag, Al, Cu, Ni, and Zn in 1-butyl-3-methylimidazolium bistriflimide ([bmim][Tf2N]) was investigated under vacuum using AR-XPS and NEXAFS. The XPS spectra show chemical shifts of the nitrogen of the bistriflimide anion as a function of the metal type, indicating different strength of the coordination bonds. In silver bearing ILs, silver ions were found to be only weakly coordinated. On the contrary, Ni, Cu, Zn, and especially Al exhibit large chemical shifts attributable to strong interaction with the bistriflimide ions. The outermost surface was enriched with or depleted of metal ions as a function of the nature of the metals. Nickel and zinc tend to slightly concentrate at the surface while copper, silver, and especially aluminum are depleted at the surface. We also observed that the aliphatic alkyl chains of the cations tend to protrude outside the surface in all systems studied. However, the presence of metals generally increases the amount of bistriflimide at the vacuum/liquid interface.

  18. Impermeable flexible liquid barrier film for encapsulation of DSSC metal electrodes

    NASA Astrophysics Data System (ADS)

    Yang, Junghee; Min, Misook; Yoon, Yeoheung; Kim, Won Jung; Kim, Sol; Lee, Hyoyoung

    2016-06-01

    Encapsulation of electronic devices such as dye-sensitized solar cells (DSSCs) is prone to degradation under normal atmospheric conditions, even with hermetic barriers on the metal electrodes. Overcoming this problem is crucial to increasing DSSC lifetimes and making them commercially viable. Herein, we report a new impermeable flexible liquid barrier film using polyvinyl alcohol (PVA) and partially reduced graphene oxide (PrGO), which dramatically enhances the lifetime of Ag metal electrodes (typically used in DSSCs) immersed in a highly acidic iodolyte solution. The Ag metal electrode encapsulated by the PVA/PrGO film survived for over 500 hrs, superior to existing barriers of glass frits, epoxy resins and polymers. The PVA/PrGO film strongly adheres to the Ag metal surface, and the resulting PVA/PrGO/Ag electrode is stable even on a curved substrate, with a sheet resistance nearly independent of curvature. These results give new insight for the design of high-performance and solution-processable flexible liquid barrier films for a wide range of applications, in particular for the encapsulation of electronic devices with liquid electrolytes.

  19. Impermeable flexible liquid barrier film for encapsulation of DSSC metal electrodes.

    PubMed

    Yang, Junghee; Min, Misook; Yoon, Yeoheung; Kim, Won Jung; Kim, Sol; Lee, Hyoyoung

    2016-01-01

    Encapsulation of electronic devices such as dye-sensitized solar cells (DSSCs) is prone to degradation under normal atmospheric conditions, even with hermetic barriers on the metal electrodes. Overcoming this problem is crucial to increasing DSSC lifetimes and making them commercially viable. Herein, we report a new impermeable flexible liquid barrier film using polyvinyl alcohol (PVA) and partially reduced graphene oxide (PrGO), which dramatically enhances the lifetime of Ag metal electrodes (typically used in DSSCs) immersed in a highly acidic iodolyte solution. The Ag metal electrode encapsulated by the PVA/PrGO film survived for over 500 hrs, superior to existing barriers of glass frits, epoxy resins and polymers. The PVA/PrGO film strongly adheres to the Ag metal surface, and the resulting PVA/PrGO/Ag electrode is stable even on a curved substrate, with a sheet resistance nearly independent of curvature. These results give new insight for the design of high-performance and solution-processable flexible liquid barrier films for a wide range of applications, in particular for the encapsulation of electronic devices with liquid electrolytes. PMID:27263654

  20. Impermeable flexible liquid barrier film for encapsulation of DSSC metal electrodes

    PubMed Central

    Yang, Junghee; Min, Misook; Yoon, Yeoheung; Kim, Won Jung; Kim, Sol; Lee, Hyoyoung

    2016-01-01

    Encapsulation of electronic devices such as dye-sensitized solar cells (DSSCs) is prone to degradation under normal atmospheric conditions, even with hermetic barriers on the metal electrodes. Overcoming this problem is crucial to increasing DSSC lifetimes and making them commercially viable. Herein, we report a new impermeable flexible liquid barrier film using polyvinyl alcohol (PVA) and partially reduced graphene oxide (PrGO), which dramatically enhances the lifetime of Ag metal electrodes (typically used in DSSCs) immersed in a highly acidic iodolyte solution. The Ag metal electrode encapsulated by the PVA/PrGO film survived for over 500 hrs, superior to existing barriers of glass frits, epoxy resins and polymers. The PVA/PrGO film strongly adheres to the Ag metal surface, and the resulting PVA/PrGO/Ag electrode is stable even on a curved substrate, with a sheet resistance nearly independent of curvature. These results give new insight for the design of high-performance and solution-processable flexible liquid barrier films for a wide range of applications, in particular for the encapsulation of electronic devices with liquid electrolytes. PMID:27263654

  1. Impermeable flexible liquid barrier film for encapsulation of DSSC metal electrodes.

    PubMed

    Yang, Junghee; Min, Misook; Yoon, Yeoheung; Kim, Won Jung; Kim, Sol; Lee, Hyoyoung

    2016-01-01

    Encapsulation of electronic devices such as dye-sensitized solar cells (DSSCs) is prone to degradation under normal atmospheric conditions, even with hermetic barriers on the metal electrodes. Overcoming this problem is crucial to increasing DSSC lifetimes and making them commercially viable. Herein, we report a new impermeable flexible liquid barrier film using polyvinyl alcohol (PVA) and partially reduced graphene oxide (PrGO), which dramatically enhances the lifetime of Ag metal electrodes (typically used in DSSCs) immersed in a highly acidic iodolyte solution. The Ag metal electrode encapsulated by the PVA/PrGO film survived for over 500 hrs, superior to existing barriers of glass frits, epoxy resins and polymers. The PVA/PrGO film strongly adheres to the Ag metal surface, and the resulting PVA/PrGO/Ag electrode is stable even on a curved substrate, with a sheet resistance nearly independent of curvature. These results give new insight for the design of high-performance and solution-processable flexible liquid barrier films for a wide range of applications, in particular for the encapsulation of electronic devices with liquid electrolytes.

  2. Failure Mechanism for Fast-Charged Lithium Metal Batteries with Liquid Electrolytes

    SciTech Connect

    Lv, DP; Shao, YY; Lozano, T; Bennett, WD; Graff, GL; Polzin, B; Zhang, JG; Engelhard, MH; Saenz, NT; Henderson, WA; Bhattacharya, P; Liu, J; Xiao, J

    2014-09-11

    In recent years, the Li metal anode has regained a position of paramount research interest because of the necessity for employing Li metal in next-generation battery technologies such as Li-S and Li-O-2. Severely limiting this utilization, however, are the rapid capacity degradation and safety issues associated with rechargeable Li metal anodes. A fundamental understanding of the failure mechanism of Li metal at high charge rates has remained elusive due to the complicated interfacial chemistry that occurs between Li metal and liquid electrolytes. Here, it is demonstrated that at high current density the quick formation of a highly resistive solid electrolyte interphase (SEI) entangled with Li metal, which grows towards the bulk Li, dramatically increases up the cell impedance and this is the actual origin of the onset of cell degradation and failure. This is instead of dendritic or mossy Li growing outwards from the metal surface towards/through the separator and/or the consumption of the Li and electrolyte through side reactions. Interphase, in this context, refers to a substantive layer rather than a thin interfacial layer. Discerning the mechanisms and consequences for this interphase formation is crucial for resolving the stability and safety issues associated with Li metal anodes.

  3. Advanced Launch Vehicle Upper Stages Using Liquid Propulsion and Metallized Propellants

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan A.

    1990-01-01

    Metallized propellants are liquid propellants with a metal additive suspended in a gelled fuel or oxidizer. Typically, aluminum (Al) particles are the metal additive. These propellants provide increase in the density and/or the specific impulse of the propulsion system. Using metallized propellant for volume-and mass-constrained upper stages can deliver modest increases in performance for low earth orbit to geosynchronous earth orbit (LEO-GEO) and other earth orbital transfer missions. Metallized propellants, however, can enable very fast planetary missions with a single-stage upper stage system. Trade studies comparing metallized propellant stage performance with non-metallized upper stages and the Inertial Upper Stage (IUS) are presented. These upper stages are both one- and two-stage vehicles that provide the added energy to send payloads to altitudes and onto trajectories that are unattainable with only the launch vehicle. The stage designs are controlled by the volume and the mass constraints of the Space Transportation System (STS) and Space Transportation System-Cargo (STS-C) launch vehicles. The influences of the density and specific impulse increases enabled by metallized propellants are examined for a variety of different stage and propellant combinations.

  4. Advanced launch vehicle upper stages using liquid propulsion and metallized propellants

    NASA Technical Reports Server (NTRS)

    Palaszewski, B. A.

    1990-01-01

    Metallized propellants are liquid propellants with a metal additive suspended in a gelled fuel or oxidizer. Typically, aluminum particles are the metal additives. These propellants provide increase in the density and/or the specific impulse of the propulsion system. Using metallized propellants for volume- and mass-constrained upper stages can deliver modest increases in performance for Low Earth Orbit to Geosynchronous Earth Orbit and other Earth orbital transfer missions. Metallized propellants, however, can enable very fast planetary missions with a single-stage upper stage system. Trade studies comparing metallized propellant stage performance with non-metallized upper stages and the Inertial Upper Stage are presented. These upper stages are both one- and two-stage vehicles that provide the added energy to send payloads to altitudes and onto trajectories that are unattainable with only the launch vehicle. The stage designs are controlled by the volume and the mass constraints of the Space Transportation System and Space Transportation System-Cargo launch vehicles. The influences of the density and specific impulse increases enabled by metallized propellants are examined for a variety of different stage and propellant combinations.

  5. Experiments with Liquid Metal Walls: Status of the Lithium Tokamak Experiment

    SciTech Connect

    Kaita, Robert; Boyle, Dennis; Gray, Timothy; Granstedt, Erik; Hammett, Gregory; Jacobson, Craig M; Jones, Andrew; Kozub, Thomas; Kugel, Henry; Leblanc, Benoit; Logan, Nicholas; Lucia, Matthew; Lundberg, Daniel; Majeski, Richard; Mansfield, Dennis; Menard, Jonathan; Spaleta, Jeffrey; Strickler, Trevor; Timberlak, John

    2010-02-16

    Liquid metal walls have been proposed to address the first wall challenge for fusion reactors. The Lithium Tokamak Experiment (LTX) at the Princeton Plasma Physics Laboratory (PPPL) is the first magnetic confinement device to have liquid metal plasma-facing components (PFC's) that encloses virtually the entire plasma. In the Current Drive Experiment-Upgrade (CDX-U), a predecessor to LTX at PPPL, the highest improvement in energy confinement ever observed in Ohmically-heated tokamak plasmas was achieved with a toroidal liquid lithium limiter. The LTX extends this liquid lithium PFC by using a conducting conformal shell that almost completely surrounds the plasma. By heating the shell, a lithium coating on the plasma-facing side can be kept liquefied. A consequence of the low-recycling conditions from liquid lithium walls is the need for efficient plasma fueling. For this purpose, a molecular cluster injector is being developed. Future plans include the installation of a neutral beam for core plasma fueling, and also ion temperature measurements using charge-exchange recombination spectroscopy. Low edge recycling is also predicted to reduce temperature gradients that drive drift wave turbulence. Gyrokinetic simulations are in progress to calculate fluctuation levels and transport for LTX plasmas, and new fluctuation diagnostics are under development to test these predictions. __________________________________________________

  6. The Connection Between Local Icosahedral Order in Metallic Liquids and the Nucleation of Ordered Phases

    NASA Technical Reports Server (NTRS)

    Curreri, Peter A. (Technical Monitor); Kelton, K. F.; Gangopadhyay, A.; Lee, G. W.; Hyers, R. W.; Rathz, R. J.; Rogers, J.; Schenk, T.; Simonet, V.; Holland-Moritz, D.

    2003-01-01

    Over fifty years ago, David Turnbull showed that the temperature of many metallic liquids could be decreased far below their equilibrium melting temperature before crystallization occurred. To explain those surprising results, Charles Frank hypothesized that the local structures of undercooled metallic liquids are different from those of crystal phases, containing a significant degree of icosahedral order that is incompatible with extended periodicity. Such structural differences must create a barrier to the formation crystal phases, explaining the observed undercooling behavior. If true, the nucleation from the liquid of phases with extended icosahedral order should be easier. Icosahedral order is often favored in small clusters, as observed recently in liquid-like clusters of pure Pb on the (111) surface of Si, for example. However, it has never been shown that an increasing preference for icosahedral phase formation can be directly linked with the development of icosahedral order in the undercooled liquid. Owing to the combination of very recent advances in levitation techniques and the availability of synchrotron x-ray and high flux neutron facilities, this is shown here.

  7. The Connection Between Local Icosahedral Order in Metallic Liquids and the Nucleation of Ordered Phases

    NASA Technical Reports Server (NTRS)

    Kelton, K. F.; Gangopadhyay, A. K.; Lee, G. W.; Hyers, R. W.; Rathz, T. J.; Rogers, J. R.; Robinson, M. B.; Schenk, T.; Simonet, V.; Holland-Moritz, D.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Over fifty years ago, David Turnbull showed that the temperature of many metallic liquids could be decreased far below their equilibrium melting temperature before crystallization occurred. To explain those surprising results, Charles Frank hypothesized that the local structures of undercooled metallic liquids are different from those of crystal phases, containing a significant degree of icosahedral order that is incompatible with extended periodicity. Such structural differences must create a barrier to the formation crystal phases, explaining the observed undercooling behavior. If true, the nucleation from the liquid of phases with extended icosahedral order should be easier. Icosahedral order is often favored in small clusters, as observed recently in liquid-like clusters of pure Pb on the (111) surface of Si(3), for example. However, it has never been shown that an increasing preference for icosahedral phase formation can be directly linked with the development of icosahedral order in the undercooled liquid. Owing to the combination of very recent advances in levitation techniques and the availability of synchrotron X-ray and high flux neutron facilities.

  8. The Connection Between Local Icosahedral Order in Metallic Liquids and the Nucleation Behavior of Ordered Phases

    NASA Technical Reports Server (NTRS)

    Kelton, K. F.; Gangopadhyay, A. K.; Lee, G. W.; Hyers, R. W.; Rathz, T. J.; Rogers, J. R.; Robinson, M. B.; Schenk, T.; Simonet, V.

    2003-01-01

    Over fifty years ago, David Turnbull showed that the temperature of many metallic liquids could be decreased far below their equilibrium melting temperature before crystallization occurred. To explain those surprising results, Charles Frank hypothesized that the local structures of undercooled metallic liquids are different from those of crystal phases, containing a significant degree of icosahedral order that is incompatible with extended periodicity. Such structural differences must create a barrier to the formation crystal phases, explaining the observed undercooling behavior. If true, the nucleation from the liquid of phases with extended icosahedral order should be easier. Icosahedral order is often favored in small clusters, as observed recently in liquid-like clusters of pure Pb on the (111) surface of Si[3], for example. However, it has never been shown that an increasing preference for icosahedral phase formation can be directly linked with the development of icosahedral order in the undercooled liquid. Owing to the combination of very recent advances in levitation techniques and the availability of synchrotron x-ray and high flux neutron facilities, this is shown here.

  9. Direct observation of an abrupt insulator-to-metal transition in dense liquid deuterium

    NASA Astrophysics Data System (ADS)

    Knudson, Marcus; Desjarlais, Michael; Becker, Andeas; Lemke, Raymond; Cochrane, Kyle; Savage, Mark; Bliss, David; Mattsson, Thomas; Redmer, Ronald

    2015-06-01

    Recently a so-called shock-ramp platform has been developed on the Sandia Z Accelerator to access off-Hugoniot states in liquids. The accelerator delivers a two-step current pulse; the first accelerates the electrode to a reasonably 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. This technique generates relatively cool (~1-2 kK), high pressure (>300 GPa), high compression (~10-15 fold compression) states, allowing experimental access to the region of phase space where hydrogen is predicted to undergo a first-order phase transition from an insulating molecular-like liquid to a conducting atomic-like liquid. In this talk we will discuss the experimental platform, survey the various theoretical predictions for the liquid-liquid, insulator-to-metal transition in hydrogen, and present the results of experiments that clearly show an abrupt transition to a metallic state. 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.

  10. Laplace-Pressure Actuation of Liquid Metal Devices For Reconfigurable Electromagnetics

    NASA Astrophysics Data System (ADS)

    Cumby, Brad Lee

    Present day electronics are now taking on small form factors, unexpected uses, adaptability, and other features that only a decade ago were unimaginable even for most engineers. These electronic devices, such as tablets, smart phones, wearable sensors, and others, have further had a profound impact on how society interacts, works, maintains health, etc. To optimize electronics a growing trend has been to both minimize the physical space taken up by the individual electronic components as well as to maximize the number of functionalities in a single electronic device, forming a compact and efficient package. To accomplish this challenge in one step, many groups have used a design that has reconfigurable electromagnetic properties, maximizing the functionality density of the device. This would allow the replacement of multiple individual components into an integrated system that would achieve a similar result as the separate individual devices while taking up less space. For example, could a device have a reconfigurable antenna, allowing it optimal communication in various settings and across multiple communication bands, thus increasing functionality, range, and even reducing total device size. Thus far a majority of such reconfigurable devices involve connecting/disconnecting various physically static layouts to achieve a summation of individual components that give rise to multiple effects. However, this is not an ideal situation due to the fact that the individual components whether connected or not are taking up real-estate as well as electrical interference with adjacent connected components. This dissertation focuses on the reconfigurability of the metallic component of the electronic device, specifically microwave devices. This component used throughout this dissertation is that of an eutectic liquid metal alloy. The liquid metal allows the utilization of both the inherent compact form (spherical shape) of a liquid in the lowest energy state and the fact that

  11. Modeling the flow of liquid-metal coolant in the T-shaped mixer

    NASA Astrophysics Data System (ADS)

    Kashinsky, O. N.; Lobanov, P. D.; Kurdyumov, A. S.; Pribaturin, N. A.

    2016-05-01

    The results of experimental studies on the structure of the temperature field in the tube cross section at the flow of liquid-metal coolant in a T-shaped mixer are presented. Experiments were carried out using the Rose alloy as the working fluid. To determine temperature distribution on the test section wall, infrared thermography was used; to determine temperature distribution in the channel cross section, a mobile thermocouple was used. Considerable temperature maldistribution in the mixing zone of liquid flows with different temperatures on the tube wall and in the coolant melt is shown.

  12. High Temperature Ultrasonic Transducers for In-Service Inspection of Liquid Metal Fast Reactors

    SciTech Connect

    Griffin, Jeffrey W.; Posakony, Gerald J.; Harris, Robert V.; Baldwin, David L.; Jones, Anthony M.; Bond, Leonard J.

    2011-12-31

    In-service inspection of liquid metal (sodium) fast reactors requires the use of ultrasonic transducers capable of operating at high temperatures (>200°C), high gamma radiation fields, and the chemically reactive liquid sodium environment. In the early- to mid-1970s, the U.S. Atomic Energy Commission supported development of high-temperature, submersible single-element transducers, used for scanning and under-sodium imaging in the Fast Flux Test Facility and the Clinch River Breeder Reactor. Current work is building on this technology to develop the next generation of high-temperature linear ultrasonic transducer arrays for under-sodium viewing and in-service inspections.

  13. Drop Dynamics and Speciation in Isolation of Metals from Liquid Wastes by Reactive Scavenging

    SciTech Connect

    Arne J. Pearlstein; Alexander Scheeline

    2002-08-30

    Computational and experimental studies of the motion and dynamics of liquid drops in gas flows were conducted with relevance to reactive scavenging of metals from atomized liquid waste. Navier-Stoke's computations of deformable drops revealed a range of conditions from which prolate drops are expected, and showed how frajectiones of deformable drops undergoing deceleration can be computed. Experimental work focused on development of emission fluorescence, and scattering diagnostics. The instrument developed was used to image drop shapes, soot, and nonaxisymmetric departures from steady flow in a 22kw combustor

  14. Nonlinear absorption in ionic liquids with transition metallic atoms in the anion

    NASA Astrophysics Data System (ADS)

    Nóvoa-López, José A.; López Lago, Elena; Seijas, Julio A.; Pilar Vázquez-Tato, M.; Troncoso, Jacobo; de la Fuente, Raúl; Salgueiro, José R.; Michinel, Humberto

    2016-02-01

    Nonlinear absorption has been investigated by open aperture Z-scan in ionic liquids obtained by combination of 1-butyl-3-methyl-imidazolium cations with anions containing a transition metal (Co, Zn, Cu or Ni) and thiocyanate groups. The laser source was a Ti:Sapphire oscillator (80-fs pulses, λ = 810 nm, repetition rate of 80.75 MHz). All liquids present quite low heat capacities that favor the development of strong thermal effects. Thermal effects and nonlinear absorption make them potential materials for optical limiting purposes.

  15. Separation of rare earths from transition metals by liquid-liquid extraction from a molten salt hydrate to an ionic liquid phase.

    PubMed

    Rout, Alok; Binnemans, Koen

    2014-02-28

    The solvent extraction of trivalent rare-earth ions and their separation from divalent transition metal ions using molten salt hydrates as the feed phase and an undiluted fluorine-free ionic liquid as the extracting phase were investigated in detail. The extractant was tricaprylmethylammonium nitrate, [A336][NO3], and the hydrated melt was calcium nitrate tetrahydrate, Ca(NO3)2·4H2O. The extraction behavior of rare-earth ions was studied for solutions of individual elements, as well as for mixtures of rare earths in the hydrated melt. The influence of different extraction parameters was investigated: the initial metal loading in the feed phase, percentage of water in the feed solution, equilibration time, and the type of hydrated melt. The extraction of rare earths from Ca(NO3)2·4H2O was compared with extraction from CaCl2·4H2O by [A336][Cl] (Aliquat 336). The nitrate system was found to be the better one. The extraction and separation of rare earths from the transition metals nickel, cobalt and zinc were also investigated. Remarkably high separation factors of rare-earth ions over transition metal ions were observed for extraction from Ca(NO3)2·4H2O by the [A336][NO3] extracting phase. Furthermore, rare-earth ions could be separated efficiently from transition metal ions, even in melts with very high concentrations of transition metal ions. Rare-earth oxides could be directly dissolved in the Ca(NO3)2·4H2O phase in the presence of small amounts of Al(NO3)3·9H2O or concentrated nitric acid. The efficiency of extraction after dissolving the rare-earth oxides in the hydrated nitrate melt was identical to extraction from solutions with rare-earth nitrates dissolved in the molten phase. The stripping of the rare-earth ions from the loaded ionic liquid phase and the reuse of the recycled ionic liquid were also investigated in detail.

  16. Solid-liquid interface free energies of pure bcc metals and B2 phases

    SciTech Connect

    Wilson, S. R.; Gunawardana, K. G. S. H.; Mendelev, M. I.

    2015-04-07

    The solid-liquid interface (SLI) free energy was determined from molecular dynamics (MD) simulation for several body centered cubic (bcc) metals and B2 metallic compounds (space group: Pm3¯m ; prototype: CsCl). In order to include a bcc metal with a low melting temperature in our study, a semi-empirical potential was developed for Na. Two additional synthetic “Na” potentials were also developed to explore the effect of liquid structure and latent heat on the SLI free energy. The obtained MD data were compared with the empirical Turnbull, Laird, and Ewing relations. All three relations are found to predict the general trend observed in the MD data for bcc metals obtained within the present study. However, only the Laird and Ewing relations are able to predict the trend obtained within the sequence of “Na” potentials. The Laird relation provides the best prediction for our MD data and other MD data for bcc metals taken from the literature. Overall, the Laird relation also agrees well with our B2 data but requires a proportionality constant that is substantially different from the bcc case. It also fails to explain a considerable difference between the SLI free energies of some B2 phases which have nearly the same melting temperature. In contrast, this difference is satisfactorily described by the Ewing relation. Thus, the Ewing relation obtained from the bcc dataset also provides a reasonable description of the B2 data.

  17. Solid-liquid interface free energies of pure bcc metals and B2 phases

    DOE PAGES

    Wilson, S. R.; Gunawardana, K. G. S. H.; Mendelev, M. I.

    2015-04-07

    The solid-liquid interface (SLI) free energy was determined from molecular dynamics (MD) simulation for several body centered cubic (bcc) metals and B2 metallic compounds (space group: Pm3¯m ; prototype: CsCl). In order to include a bcc metal with a low melting temperature in our study, a semi-empirical potential was developed for Na. Two additional synthetic “Na” potentials were also developed to explore the effect of liquid structure and latent heat on the SLI free energy. The obtained MD data were compared with the empirical Turnbull, Laird, and Ewing relations. All three relations are found to predict the general trend observedmore » in the MD data for bcc metals obtained within the present study. However, only the Laird and Ewing relations are able to predict the trend obtained within the sequence of “Na” potentials. The Laird relation provides the best prediction for our MD data and other MD data for bcc metals taken from the literature. Overall, the Laird relation also agrees well with our B2 data but requires a proportionality constant that is substantially different from the bcc case. It also fails to explain a considerable difference between the SLI free energies of some B2 phases which have nearly the same melting temperature. In contrast, this difference is satisfactorily described by the Ewing relation. Thus, the Ewing relation obtained from the bcc dataset also provides a reasonable description of the B2 data.« less

  18. Liquid metal alloy ion source based metal ion injection into a room-temperature electron beam ion source

    SciTech Connect

    Thorn, A.; Ritter, E.; Zschornack, G.; Ullmann, F.; Pilz, W.; Bischoff, L.

    2012-02-15

    We have carried out a series of measurements demonstrating the feasibility of using the Dresden electron beam ion source (EBIS)-A, a table-top sized, permanent magnet technology based electron beam ion source, as a charge breeder. Low charged gold ions from an AuGe liquid metal alloy ion source were injected into the EBIS and re-extracted as highly charged ions, thereby producing charge states as high as Au{sup 60+}. The setup, the charge breeding technique, breeding efficiencies as well as acceptance and emittance studies are presented.

  19. Liquid metal loop of the LiSoR experimental facility.

    NASA Astrophysics Data System (ADS)

    Dementev, S.; Glasbrenner, H.; Kirchner, T.; Heinrich, F.; Bucenieks, I.; Platacis, E.; Pozdnjaks, A.; Krisko, S.; Kirshtein, G.; Mikoelov, A.

    2001-12-01

    The LBE (eutectic Pb-Bi) loop for LiSoR (Liquid metal Solid metal Reaction) experiment has been designed, fabricated and tested basing on the severe constraint to operate under irradiation conditions. An experience of calculation, design and fabrication of LBE loop for operating in an irradiation facility is accumulated. The results of the LiSoR irradiation experiments will be an important contribution to the selection of spallation target materials for accelerator-driven system applications. Tables 2, Figs 10, Refs 7.

  20. Polarization and mass transfer during the electrolysis of molten salts with liquid metallic electrodes

    NASA Astrophysics Data System (ADS)

    Mikhalev, Yu. G.

    2014-08-01

    Calculations are used to show that the fraction of the overvoltage of the stage of discharge-ionization can be significant in the total overvoltage during the polarization of liquid metallic electrodes in molten chlorides depleted of electrochemically active particles (depending on the type of the dissipative structures that appear near the electrode/electrolyte interface). This finding is taken into account to obtain criterion equations to describe the mass-transfer rate as a function of the physicochemical properties of the electrolyte and the metal electrode.

  1. Failures in large gas turbines due to liquid-metal embrittlement

    SciTech Connect

    Cameron, D.W. . Turbo Products Division)

    1994-07-01

    The failures of three gas turbine components, attributed to liquid-metal embrittlement or solid-metal-induced embrittlement, are described. High temperatures inherent in the gas turbine can aggravate these phenomenon if the necessary conditions are present. Examples chosen include a power transmission shaft, flange bolts from a cooling steam line, and a turbine rotor bolt. The respective material couples involved are 17-4PH stainless steel-copper, AISI 4130-cadmium, and IN 718-cadmium. Each case includes information on the source of the aggressive material and relevant operating environment. The implications of the failures with regard to the general failure mechanism are briefly discussed.

  2. Conversion of light hydrocarbon gases to metal carbides for production of liquid fuels and chemicals

    SciTech Connect

    Diaz, A.F.; Modestino, A.J.; Howard, J.B.; Peters, W.A.

    1993-02-01

    Light hydrocarbon gases could be reacted with low cost alkaline earth metal oxide (CaO, MgO) in high-temperature plasma reactor to achieve very high ([le]100%) gas conversion to H[sub 2], CO, and the corresponding metal carbides. These carbides could be stored, transported, and hydrolyzed to acetylene or methyl acetylene, which in turn could be upgraded to a wide range of chemicals and premium liquid hydrocarbon fuels. An electric arc discharge reactor was built for converting methane. Literature reviews were made.

  3. Empirical equation for predicting the surface tension of some liquid metals at their melting point

    NASA Astrophysics Data System (ADS)

    Ceotto, D.

    2014-07-01

    A new empirical equation is proposed for predicting the surface tension of some pure metals at their melting point. The investigation has been conducted adopting a statistical approach using some of the most accredited data available in literature. It is found that for Ag, Al, Au, Co, Cu, Fe, Ni, and Pb the surface tension can be conveniently expressed in function of the latent heat of fusion and of the geometrical parameters of an ideal liquid spherical drop. The equation proposed has been compared also with the model proposed by Lu and Jiang giving satisfactory agreement for the metals considered.

  4. Experimental evidence for Mo isotope fractionation between metal and silicate liquids

    NASA Astrophysics Data System (ADS)

    Hin, Remco C.; Burkhardt, Christoph; Schmidt, Max W.; Bourdon, Bernard; Kleine, Thorsten

    2013-10-01

    Stable isotope fractionation of siderophile elements may inform on the conditions and chemical consequences of core-mantle differentiation in planetary objects. The extent to which Mo isotopes fractionate during such metal-silicate segregation, however, is so far unexplored. We have therefore investigated equilibrium fractionation of Mo isotopes between liquid metal and liquid silicate to evaluate the potential of Mo isotopes as a new tool to study core formation. We have performed experiments at 1400 and 1600 °C in a centrifuging piston cylinder. Tin was used to lower the melting temperature of the Fe-based metal alloys to <1400 °C, while variable Fe-oxide contents were used to vary oxygen fugacity in graphite and MgO capsules. Isotopic analyses were performed using a double spike technique. In experiments performed at 1400 °C, the 98Mo/95Mo ratio of silicate is 0.19±0.03‰ (95% confidence interval) heavier than that of metal. This fractionation is not significantly affected by the presence or absence of carbon. Molybdenum isotope fractionation is furthermore independent of oxygen fugacity in the range IW -1.79 to IW +0.47, which are plausible values for core formation. Experiments at 1600 °C show that, at equilibrium, the 98Mo/95Mo ratio of silicate is 0.12±0.02‰ heavier than that of metal and that the presence or absence of Sn does not affect this fractionation. Equilibrium Mo isotope fractionation between liquid metal and liquid silicate as a function of temperature can therefore be described as ΔMoMetal-Silicate98/95=-4.70(±0.59)×105/T2. Our experiments show that Mo isotope fractionation may be resolvable up to metal-silicate equilibration temperatures of about 2500 °C, rendering Mo isotopes a novel tool to investigate the conditions of core formation in objects ranging from planetesimals to Earth sized bodies.

  5. Study of the design model of a liquid metal induction pump

    SciTech Connect

    Borghi, C.A.; Cristofolini, A.; Fabbri, M.

    1998-09-01

    The determination of the geometry and of the electrical configuration of an MHD device gives rise to an inverse magnetohydrodynamic field problem. Here, the design of an electromagnetic pump for liquid metal is optimized. The model includes both electrodynamics and fluid-dynamics of the liquid metal. End effects are included in the model, in order to take into account the finite length of the pump and consequently the decrease of efficiency. For the Electrodynamic model, the permeability of the ferromagnetic core is assumed to be infinite. A finite slot configuration of the primary windings is assumed. In the design problem considered, the optimization regards the electrical supply system, the pump dimensions and the slot configuration.

  6. Theoretical and numerical stability analysis of the liquid metal pinch using the shallow water approximation

    NASA Astrophysics Data System (ADS)

    Zienicke, E.; Li, Ben-Wen; Thess, A.; Kräzschmar, A.; Terhoeven, P.

    2008-09-01

    The pinch instability for a cylindrical jet of liquid metal passed through by an axial electrical current is investigated. Besides the pinch effect originating from surface tension, the Lorentz force, created by the axial current density and the corresponding azimuthal magnetic field, causes an electromagnetic pinch effect. This effect has drawn attention in electrical engineering, because it can be used in the construction of liquid metal current limiters with self-healing properties. In this paper a simple model is derived using the shallow water approximation: the equations describing the full system are reduced to two one-dimensional evolution equations for the axial velocity and the radius of the jet. A stability analysis for this reduced system is carried out yielding critical current density and the growth rate for the instability. To investigate the nonlinear behaviour of the pinch instability for finite perturbations simulations, the shallow water model are performed.

  7. Establishing low-power operating limits for liquid metal heat pipes

    SciTech Connect

    Secary, J.; Merrigan, M.A.; Keddy, M.D.

    1992-05-01

    Liquid metal heat pipes operated at power throughputs well below their design point for long durations may fail as a result of the working fluid migrating to a cold region within the pipe, freezing there, and hot returning to the evaporator section. Eventually sufficient working fluid inventory may be lost to the cold region to cause a local dry-out condition in the evaporator. A joint experimental and analytical effort between the Air Force Phillips Laboratory and Los Alamos National Laboratory is underway to investigate the phenomena. Experiments include both high temperature liquid metal and low temperature organic heat pipes. To date, a low temperature working fluid has been selected and its performance in a heat pipe validated. Additionally, a low-temperature heat pipe has been fabricated and is presently being tested.

  8. Establishing low-power operating limits for liquid metal heat pipes

    NASA Astrophysics Data System (ADS)

    Secary, J.; Merrigan, M. A.; Keddy, M. D.

    Liquid metal heat pipes operated at power throughputs well below their design point for long durations may fail as a result of the working fluid migrating to a cold region within the pipe, freezing there, and returning hot to the evaporator section. Eventually, sufficient working fluid inventory may be lost to the cold region to cause a local dry-out condition in the evaporator. A joint experimental and analytical effort between the Air Force Phillips Laboratory and Los Alamos National Laboratory is underway to investigate the phenomena. Experiments include both high temperature liquid metal and low temperature organic heat pipes. To date, a low temperature working fluid has been selected and its performance in a heat pipe validated. Additionally, a low-temperature heat pipe has been fabricated and is presently being tested.

  9. Experimental Evidence for a Transient Tayler Instability in a Cylindrical Liquid-Metal Column

    NASA Astrophysics Data System (ADS)

    Seilmayer, Martin; Stefani, Frank; Gundrum, Thomas; Weier, Tom; Gerbeth, Gunter; Gellert, Marcus; Rüdiger, Günther

    2012-06-01

    In the current-driven, kink-type Tayler instability (TI) a sufficiently strong azimuthal magnetic field becomes unstable against nonaxisymmetric perturbations. The TI has been discussed as a possible ingredient of the solar dynamo mechanism and a source of the helical structures in cosmic jets. It is also considered as a size-limiting factor for liquid metal batteries. We report on a liquid metal TI experiment using a cylindrical column of the eutectic alloy GaInSn to which electrical currents of up to 8 kA are applied. We present results of external magnetic field measurements that indicate the transient occurrence of the TI in good agreement with numerical predictions. The interference of TI with the competing large-scale convection, resulting from Joule heating, is also discussed.

  10. Evaluation of liquid metal embrittlement of SS304 by Cd and Cd-Al solutions

    SciTech Connect

    Thomas, J.K.; Iyer, N.C.; Begley, J.A.

    1992-07-01

    The susceptibility of stainless steel 304 to liquid metal embrittlement (LME) by cadmium (Cd) and cadmium-aluminum (Cd-Al) solutions was examined as part of a failure evaluation for SS304-clad cadmium reactor safety rods which had been exposed to elevated temperatures. The active, or cadmium (Cd) bearing, portion of the safety rod consists of a 0.756 in. diameter aluminum allow (Al-6061) core, a 0.05 in. thick Cd layer, and a 0.042 in. thick Type 304 stainless steel cladding. The safety rod thermal tests were conducted as part of a program to define the response of reactor core components to a hypothetical LOCA for the Savannah River Site (SRS) production reactor. LME was considered as a potential failure mechanism based on the nature of the failure and susceptibility of austenitic stainless steels to embrittlement by other liquid metals.

  11. Evaluation of liquid metal embrittlement of SS304 by Cd and Cd-Al solutions

    SciTech Connect

    Thomas, J.K.; Iyer, N.C. ); Begley, J.A. )

    1992-01-01

    The susceptibility of stainless steel 304 to liquid metal embrittlement (LME) by cadmium (Cd) and cadmium-aluminum (Cd-Al) solutions was examined as part of a failure evaluation for SS304-clad cadmium reactor safety rods which had been exposed to elevated temperatures. The active, or cadmium (Cd) bearing, portion of the safety rod consists of a 0.756 in. diameter aluminum allow (Al-6061) core, a 0.05 in. thick Cd layer, and a 0.042 in. thick Type 304 stainless steel cladding. The safety rod thermal tests were conducted as part of a program to define the response of reactor core components to a hypothetical LOCA for the Savannah River Site (SRS) production reactor. LME was considered as a potential failure mechanism based on the nature of the failure and susceptibility of austenitic stainless steels to embrittlement by other liquid metals.

  12. Microencapsulation of gallium-indium (Ga-In) liquid metal for self-healing applications.

    PubMed

    Blaiszik, B J; Jones, A R; Sottos, N R; White, S R

    2014-01-01

    Microcapsules containing a liquid metal alloy core of gallium-indium (Ga-In) are prepared via in situ urea-formaldehyde (UF) microencapsulation. The capsule size, shape, thermal properties, and shell wall thickness are investigated. We prepare ellipsoidal capsules with major and minor diameter aspect ratios ranging from 1.64 to 1.08 and with major diameters ranging from 245 µm to 3 µm. We observe that as the capsule major diameter decreases, the aspect ratio approaches 1. The thermal properties of the prepared microcapsules are investigated by thermogravimetric (TGA) and differential scanning calorimetry (DSC). Microcapsules are shown to survive incorporation into an epoxy matrix and to trigger via mechanical damage to the cured matrix. Microcapsules containing liquid metal cores may have diverse applications ranging from self-healing to contrast enhancement or the demonstration of mechano-adaptive circuitry.

  13. On the behavior and stability of a liquid metal in quasi-planar electric contacts

    NASA Astrophysics Data System (ADS)

    Samuilov, S. D.

    2016-06-01

    The contacts between conductors formed under relatively low pressures can be treated as quasi-planar. Melting of the material of such contacts upon the passage of electric current is used in some technological processes, but the behavior of liquid in these conditions has not been analyzed. In this study, such an estimate was obtained for specific conditions appearing under electric-pulse compacting (briquetting) of metal shavings. Analysis of derived relations shows that this estimate is valid for any quasi-2D contacts upon passage of a pulsed current of duration from microseconds to milliseconds. It is shown that the spacing between contact surfaces decreases, the liquid metal is extruded in the lateral directions, and the area of the contact and its conductivity increase. Sausage-type magnetohydrodynamic (MHD) instability and overheating instability do not evolve in these conditions because the instability wavelength is larger than the rated thickness of the molten layer; screw MHD instability can appear in slower processes.

  14. Physical model of the vapor-liquid (insulator-metal) transition in an exciton gas

    SciTech Connect

    Khomkin, A. L. Shumikhin, A. S.

    2015-04-15

    We propose a simple physical model describing the transition of an exciton gas to a conducting exciton liquid. The transition occurs due to cohesive coupling of excitons in the vicinity of the critical point, which is associated with transformation of the exciton ground state to the conduction band and the emergence of conduction electrons. We calculate the cohesion binding energy for the exciton gas and, using it, derive the equations of state, critical parameters, and binodal. The computational method is analogous to that used by us earlier [5] for predicting the vapor-liquid (insulator-metal) phase transition in atomic (hypothetical, free of molecules) hydrogen and alkali metal vapors. The similarity of the methods used for hydrogen and excitons makes it possible to clarify the physical nature of the transition in the exciton gas and to predict more confidently the existence of a new phase transition in atomic hydrogen.

  15. An Electrochemical Investigation of the Chemical Diffusivity in Liquid Metal Alloys

    NASA Astrophysics Data System (ADS)

    Barriga, Salvador A.

    The liquid metal battery has been shown to be a viable candidate for grid-scale energy storage, due to its fast kinetics and ability to be constructed from economically feasible materials. Various of the liquid metal couples that form high stable voltages, such as the calcium chemistries, are rate limited because they tend to form solid intermetallic compounds with high melting points. In order to understand and better engineer these batteries, the kinetic properties of these liquid alloys, in particular the chemical diffusivity, must be known accurately so that it can be used as input in computational simulations to avoid the nucleation of any solids. Unfortunately, the dominant experimental methods for measuring diffusion in liquid metals today are unreliable because the measurement timescales are on the order of days, require long capillaries susceptible to buoyancy-driven flow from temperature fluctuations, and composition analysis must be done ex-situ as a solid. To counter all these problems, a new and novel method for measuring the chemical diffusivity of metals in liquid alloys derived from electrochemical principles is presented in this thesis. This new method has the advantage of operating in shorter times scales of minutes rather than days, and requires the use of small capillaries which collectively minimize the effect of convectively-driven flow caused from temperature gradients. This new method was derived by solving the same boundary conditions required by the galvanostatic intermittent titration technique for solid-state electrodes. To verify the validity of the new theoretical derivation, the method was used to measure the chemical diffusivity of calcium in liquid bismuth within the temperature range of 550 - 700 °C using a three-electrode setup with a ternary molten salt electrolyte. Three compositions where studied (5% Ca-Bi, 10% Ca-Bi, and 15% Ca-Bi) for comparison. The chemical diffusion coefficient was found to range between (6.77 +/- 0.21)x

  16. Ionic liquid electrolytes as a platform for rechargeable metal-air batteries: a perspective.

    PubMed

    Kar, Mega; Simons, Tristan J; Forsyth, Maria; MacFarlane, Douglas R

    2014-09-21

    Metal-air batteries are a well-established technology that can offer high energy densities, low cost and environmental responsibility. Despite these favourable characteristics and utilisation of oxygen as the cathode reactant, these devices have been limited to primary applications, due to a number of problems that occur when the cell is recharged, including electrolyte loss and poor efficiency. Overcoming these obstacles is essential to creating a rechargeable metal-air battery that can be utilised for efficiently capturing renewable energy. Despite the first metal-air battery being created over 100 years ago, the emergence of reactive metals such as lithium has reinvigorated interest in this field. However the reactivity of some of these metals has generated a number of different philosophies regarding the electrolyte of the metal-air battery. Whilst much is already known about the anode and cathode processes in aqueous and organic electrolytes, the shortcomings of these electrolytes (i.e. volatility, instability, flammability etc.) have led some of the metal-air battery community to study room temperature ionic liquids (RTILs) as non-volatile, highly stable electrolytes that have the potential to support rechargeable metal-air battery processes. In this perspective, we discuss how some of these initial studies have demonstrated the capabilities of RTILs as metal-air battery electrolytes. We will also show that much of the long-held mechanistic knowledge of the oxygen electrode processes might not be applicable in RTIL based electrolytes, allowing for creative new solutions to the traditional irreversibility of the oxygen reduction reaction. Our understanding of key factors such as the effect of catalyst chemistry and surface structure, proton activity and interfacial reactions is still in its infancy in these novel electrolytes. In this perspective we highlight the key areas that need the attention of electrochemists and battery engineers, in order to progress

  17. Passive cooling system for liquid metal cooled nuclear reactors with backup coolant flow path

    DOEpatents

    Hunsbedt, Anstein; Boardman, Charles E.

    1993-01-01

    A liquid metal cooled nuclear fission reactor plant having a passive auxiliary safety cooling system for removing residual heat resulting from fuel decay during reactor shutdown, or heat produced during a mishap. This reactor plant is enhanced by a backup or secondary passive safety cooling system which augments the primary passive auxiliary cooling system when in operation, and replaces the primary system when rendered inoperable.

  18. Passive cooling system for top entry liquid metal cooled nuclear reactors

    DOEpatents

    Boardman, Charles E.; Hunsbedt, Anstein; Hui, Marvin M.

    1992-01-01

    A liquid metal cooled nuclear fission reactor plant having a top entry loop joined satellite assembly with a passive auxiliary safety cooling system for removing residual heat resulting from fuel decay during shutdown, or heat produced during a mishap. This satellite type reactor plant is enhanced by a backup or secondary passive safety cooling system which augments the primary passive auxiliary cooling system when in operation, and replaces the primary cooling system when rendered inoperative.

  19. Lithium-antimony-lead liquid metal battery for grid-level energy storage

    NASA Astrophysics Data System (ADS)

    Wang, Kangli; Jiang, Kai; Chung, Brice; Ouchi, Takanari; Burke, Paul J.; Boysen, Dane A.; Bradwell, David J.; Kim, Hojong; Muecke, Ulrich; Sadoway, Donald R.

    2014-10-01

    The ability to store energy on the electric grid would greatly improve its efficiency and reliability while enabling the integration of intermittent renewable energy technologies (such as wind and solar) into baseload supply. Batteries have long been considered strong candidate solutions owing to their small spatial footprint, mechanical simplicity and flexibility in siting. However, the barrier to widespread adoption of batteries is their high cost. Here we describe a lithium-antimony-lead liquid metal battery that potentially meets the performance specifications for stationary energy storage applications. This Li||Sb-Pb battery comprises a liquid lithium negative electrode, a molten salt electrolyte, and a liquid antimony-lead alloy positive electrode, which self-segregate by density into three distinct layers owing to the immiscibility of the contiguous salt and metal phases. The all-liquid construction confers the advantages of higher current density, longer cycle life and simpler manufacturing of large-scale storage systems (because no membranes or separators are involved) relative to those of conventional batteries. At charge-discharge current densities of 275 milliamperes per square centimetre, the cells cycled at 450 degrees Celsius with 98 per cent Coulombic efficiency and 73 per cent round-trip energy efficiency. To provide evidence of their high power capability, the cells were discharged and charged at current densities as high as 1,000 milliamperes per square centimetre. Measured capacity loss after operation for 1,800 hours (more than 450 charge-discharge cycles at 100 per cent depth of discharge) projects retention of over 85 per cent of initial capacity after ten years of daily cycling. Our results demonstrate that alloying a high-melting-point, high-voltage metal (antimony) with a low-melting-point, low-cost metal (lead) advantageously decreases the operating temperature while maintaining a high cell voltage. Apart from the fact that this finding

  20. Deformation of glass forming metallic liquids: Configurational changes and their relation to elastic softening

    SciTech Connect

    Harmon, John S.; Demetriou, Marios D.; Johnson, William L.; Tao, Min

    2007-03-26

    The change in the configurational enthalpy of metallic glass forming liquids induced by mechanical deformation and its effect on elastic softening is assessed. The acoustically measured shear modulus is found to decrease with increasing configurational enthalpy by a dependence similar to one obtained by softening via thermal annealing. This establishes that elastic softening is governed by a unique functional relationship between shear modulus and configurational enthalpy.

  1. Use of liquid metals in nuclear and thermonuclear engineering, and in other innovative technologies

    NASA Astrophysics Data System (ADS)

    Rachkov, V. I.; Arnol'dov, M. N.; Efanov, A. D.; Kalyakin, S. G.; Kozlov, F. A.; Loginov, N. I.; Orlov, Yu. I.; Sorokin, A. P.

    2014-05-01

    By now, a good deal of experience has been gained with using liquid metals as coolants in nuclear power installations; extensive knowledge has been gained about the physical, thermophysical, and physicochemical properties of these coolants; and the scientific principles and a set of methods and means for handling liquid metals as coolants for nuclear power installations have been elaborated. Prototype and commercialgrade sodium-cooled NPP power units have been developed, including the BOR-60, BN-350, and BN-600 power units (the Soviet Union); the Rapsodie, Phenix, and Superphenix power units (France), the EBR-II power unit (the United States); and the PFR power unit (the United Kingdom). In Russia, dedicated nuclear power installations have been constructed, including those with a lead-bismuth coolant for nuclear submarines and with sodium-potassium alloy for spacecraft (the Buk and Topol installations), which have no analogs around the world. Liquid metals (primarily lithium and its alloy with lead) hold promise for use in thermonuclear power engineering, where they can serve not only as a coolant, but also as tritium-producing medium. In this article, the physicochemical properties of liquid metal coolants, as well as practical experience gained from using them in nuclear and thermonuclear power engineering and in innovative technologies are considered, and the lines of further research works are formulated. New results obtained from investigations carried out on the Pb-Bi and Pb for the SVBR and BREST fast-neutron reactors (referred to henceforth as fast reactors) and for controlled accelerator systems are described.

  2. Surface modes in "photonic cholesteric liquid crystal-phase plate-metal" structure.

    PubMed

    Vetrov, S Ya; Pyatnov, M V; Timofeev, I V

    2014-05-01

    The light transmission spectrum has been calculated for a "cholesteric liquid crystal-phase plate-metal" structure. It is shown that the system can have an isolated waveguide surface mode with characteristics efficiently controllable by external fields acting on the cholesteric. The degree of localization of surface modes and the transmission coefficients have been found to differ considerably for the light of different polarizations. PMID:24784092

  3. Measurements of thermal-hydraulic parameters in liquid-metal-cooled fast-breeder reactors

    SciTech Connect

    Sackett, J.I.

    1983-01-01

    This paper discusses instrumentation for liquid-metal-cooled fast breeder reactors (LMFBR's). Included is instrumentation to measure sodium flow, pressure, temperature, acoustic noise, sodium purity, and leakage. The paper identifies the overall instrumentation requirements for LMFBR's and those aspects of instrumentation which are unique or of special concern to LMFBR systems. It also gives an overview of the status of instrument design and performance.

  4. Fast Fabrication of Flexible Functional Circuits Based on Liquid Metal Dual-Trans Printing.

    PubMed

    Wang, Qian; Yu, Yang; Yang, Jun; Liu, Jing

    2015-11-25

    A dual-trans method to print the first functional liquid-metal circuit layout on poly(vinyl chloride) film, and then transfer it into a poly(dimethylsiloxane) substrate through freeze phase transition processing for the fabrication of a flexible electronic device. A programmable soft electronic band and a temperature-sensing module wirelessly communicate with a mobile phone, demonstrating the efficiency and capability of the method.

  5. The liquid metal slip ring experiment for the Communications Technology Satellite.

    NASA Technical Reports Server (NTRS)

    Lovell, R. R.

    1972-01-01

    Description of an experiment designed to demonstrate liquid metal slip ring (LMSR) performance in a space environment. The experiment, based on currently developed LMSR technology, is to make possible an evaluation of those features of a LMSR where improvement in performance over conventional slip rings might be feasible. The experiment-prompting, potential LMSR advantages include: lower electrical noise, higher current capability, higher voltage capability, longer life, and small variation in friction torque.

  6. Stretchable, High-k Dielectric Elastomers through Liquid-Metal Inclusions.

    PubMed

    Bartlett, Michael D; Fassler, Andrew; Kazem, Navid; Markvicka, Eric J; Mandal, Pratiti; Majidi, Carmel

    2016-05-01

    An all-soft-matter composite with exceptional electro-elasto properties is demonstrated by embedding liquid-metal inclusions in an elastomer matrix. This material exhibits a unique combination of high dielectric constant, low stiffness, and large strain limit (ca. 600% strain). The elasticity, electrostatics, and electromechanical coupling of the composite are investigated, and strong agreement with predictions from effective medium theory is found. PMID:27007888

  7. Analysis of the free-fall behavior of liquid-metal drops in a gaseous atmosphere

    NASA Technical Reports Server (NTRS)

    Mccoy, J. Kevin; Markworth, Alan J.; Collings, E. W.; Brodkey, Robert S.

    1987-01-01

    The free-fall of a liquid-metal drop and heat transfer from the drop to its environment are described for both a gaseous atmosphere and vacuum. A simple model, in which the drop is assumed to fall rectilinearly with behavior like that of a rigid particle, is developed first, then possible causes of deviation from this behavior are discussed. The model is applied to describe solidification of drops in a drop tube. Possible future developments of the model are suggested.

  8. Observation of Magnetocoriolis Waves in a Liquid Metal Taylor-Couette Experiment

    SciTech Connect

    Nornberg, M. D.; Ji, H.; Schartman, E.; Roach, A.; Goodman, J.

    2010-02-19

    The first observation of fast and slow magnetocoriolis (MC) waves in a laboratory experiment is reported. Rotating nonaxisymmetric modes arising from a magnetized turbulent Taylor-Couette flow of liquid metal are identified as the fast and slow MC waves by the dependence of the rotation frequency on the applied field strength. The observed slow MC wave is damped but the observation provides a means for predicting the onset of the magnetorotational instability.

  9. Observation of Magnetocoriolis Waves in a Liquid Metal Taylor-Couette Experiment

    SciTech Connect

    Nornberg, M. D.; Ji, H.; Schartman, E.; Roach, A.; Goodman, J.

    2009-09-14

    The first observation of fast and slow magnetocoriolis (MC) waves in a laboratory experiment is reported. Rotating nonaxisymmetric modes arising from a magnetized turbulent Taylor-Couette flow of liquid metal are identified as the fast and slow MC waves by the dependence of the rotation frequency on the applied field strength. The observed slow MC wave is marginally damped but will become destabilized by the magnetorotational instability with a modest increase in rotation rate.

  10. Low-temperature liquid precursors of crystalline metal oxides assisted by heterogeneous photocatalysis.

    PubMed

    Bretos, Iñigo; Jiménez, Ricardo; Pérez-Mezcua, Dulce; Salazar, Norberto; Ricote, Jesús; Calzada, M Lourdes

    2015-04-24

    The photocatalytically assisted decomposition of liquid precursors of metal oxides incorporating TiO2 particles enables the preparation of functional layers from the ferroelectric Pb(Zr,Ti)O3 and multiferroic BiFeO3 perovskite systems at temperatures not exceeding 350 ºC. This enables direct deposition on flexible plastic, where the multifunctionality provided by these complex-oxide materials guarantees their potential use in next-generation flexible electronics.

  11. Dissolution of D2EHPA in liquid-liquid extraction process: implication on metal removal and organic content of the treated water.

    PubMed

    Lee, Po-Ching; Li, Chi-Wang; Chen, Jie-Yuan; Li, Ying-Sheng; Chen, Shiao-Shing

    2011-11-15

    Effects of pH, extractant/diluent ratios, and metal concentrations on the extent of extractant dissolution during liquid-liquid extraction were investigated. Experimental result shows that D(2)EHPA dissolution increases dramatically at pH above 4, leveling off at pH 6-7. The phenomenon is consistent with deprotonation of D(2)EHPA and the domination of negatively charged D(2)EHPA species at pH of higher than 4. Concentration of D(2)EHPA in the aqueous phase, i.e., the extent of extractant dissolution, drops after addition of metal and decreases with increasing metal concentration. The amount of D(2)EHPA 're-entering' the organic phase is calculated to be 2.04 mol per mol of Cd added, which is quite closed to the stoichiometric molar ratio of 2 between D(2)EHPA and Cd via ion exchange reaction. The effect of metal species on the extent of extractant/metal complexes re-entering is in the order of Cd ≈ Zn > Ag, which might be coincident to the complexation stability of these metals with D(2)EHPA. The extent of extractant dissolution in liquid-liquid extraction process depends on the type and concentration of metal to be removed, pH of aqueous phase, and extractant/diluent ratios. PMID:21937070

  12. Colloidal interactions and self-assembly of plasmonic metal pyramids in nematic liquid crystals

    NASA Astrophysics Data System (ADS)

    Park, Sungoh; Smalyukh, Ivan

    Combining ordered structure of soft matter systems, such as liquid crystals, with the unique optical properties of metal nano- and micro-particles is a promising approach of designing and realizing mesostructured composites with pre-engineered properties. In this work, we disperse nanofabricated pyramid-shaped plasmonic particles in a nematic host fluid and demonstrate that the particles spontaneously align with respect to the uniform far-field liquid crystal director. This alignment is driven by minimization of the surface anchoring and bulk elastic free energies of the nematic host. Interestingly, multiple stable and metastable orientations of these particles can be controllably observed. Using laser tweezers and video microscopy, we explore inter-particle pair interaction forces as well as the ensuing colloidal self-assembly. We analyze this experimentally observed rich physical behavior of our soft matter composite by invoking electrostatic multipole analogy of elastic distortions induced by the particles in a nematic liquid crystal host and discuss potential practical uses.

  13. Velocity and flow rate measurement of liquid metal by contactless electromagnetic Lorentz force technique

    NASA Astrophysics Data System (ADS)

    Dubovikova, N.; Karcher, C.; Kolesnikov, Y.

    2016-07-01

    Providing flow analysis in case of aggressive and hot liquids is a complicated task, especially when liquid's composition and, hence, its physical properties, are unknown. Contactless techniques are the most promising methods for liquid metal flow rate control and some of these methods are based on electromagnetic induction of breaking force acting on an electrically conductive fluid which is moving through a magnetic field. One of the techniques is time-of-flight Lorentz force velocimetry (LFV). By using the method one can estimate volumetric flow rate without knowing of electrical conductivity, magnitude of magnetic field or characteristic dimension. The most important and crucial challenge within the technique is detection of small fluctuations of Lorentz force value. In this article we will focus on application and investigation of time-of-flight LFV.

  14. Confinement transition to density wave order in metallic doped spin liquids

    NASA Astrophysics Data System (ADS)

    Patel, Aavishkar A.; Chowdhury, Debanjan; Allais, Andrea; Sachdev, Subir

    2016-04-01

    Insulating quantum spin liquids can undergo a confinement transition to a valence bond solid via the condensation of topological excitations of the associated gauge theory. We extend the theory of such transitions to fractionalized Fermi liquids (FL*): These are metallic doped spin liquids in which the Fermi surfaces only have gauge neutral quasiparticles. Using insights from a duality transform on a doped quantum dimer model for the U(1)-FL* state, we show that projective symmetry group of the theory of the topological excitations remains unmodified, but the Fermi surfaces can lead to additional frustrating interactions. We propose a theory for the confinement transition of Z2-FL* states via the condensation of visons. A variety of confining, incommensurate density wave states are possible, including some that are similar to the incommensurate d -form factor density wave order observed in several recent experiments on the cuprate superconductors.

  15. Surface tension induced convection in encapsulated liquid metals in a microgravity environment. Experiment MA-041

    NASA Technical Reports Server (NTRS)

    Reed, R. E.; Uelhoff, W.; Adair, H. L.

    1977-01-01

    The experiment was designed to detect possible convection caused by a steplike compositional variation in a liquid metal in a microgravity environment. Wetting and nonwetting ampoules were used to try to determine the extent of the stirring effects if they were present. Since stirring effects can be caused by temperature gradients, the temperature gradients were minimized. Steplike compositional variation was created by pressure bonding a lead-0.05 atom percent gold alloy to pure lead. Two diffusion temperatures (923 K and 723 K) were used; if no stirring effects were present, it was hoped that the liquid diffusion parameters for gold in lead could be obtained. Two identifical experimental arrangements were used to compare the transport mechanisms of gold in liquid lead in unit gravity and microgravity environments.

  16. Behavior of ceramic particles at the solid-liquid metal interface in metal matrix composites

    NASA Technical Reports Server (NTRS)

    Stefanescu, D. M.; Dhindaw, B. K.; Kacar, S. A.; Moitra, A.

    1988-01-01

    Directional solidification results were obtained in order to investigate particle behavior at the solid-liquid interface in Al-2 pct Mg (cellular interface) and Al-6.1 pct Ni (eutectic interface) alloys. It is found that particles can be entrapped in the solid if adequate solidification rates and temperature gradients are used. Model results showed critical velocity values slightly higher than those obtained experimentally.

  17. Lightning strike fusion: extreme reduction and metal-silicate liquid immiscibility.

    PubMed

    Essene, E J; Fisher, D C

    1986-10-10

    A glassy fulgurite, formed recently on a morainal ridge in southeastern Michigan, contains micrometer- to centimeter-sized metallic globules rich in native silicon, which unmixed from a silica-rich liquid. The unusual character of these globules and their potential for elucidating conditions of fulgurite formation prompted further study. Thermodynamic calculations indicate that temperatures in excess of 2000 K and reducing conditions approaching those of the SiO(2)-Si buffer were needed to form the coexisting metallic and silicate liquids. The phases produced are among the most highly reduced naturally occurring materials known. Some occurrences of other highly reduced minerals may also be due to lightning strike reduction. Extreme reduction and volatilization may also occur during high-temperature events such as lightning strikes in presolar nebulae and impacts of extraterrestrial bodies. As a result of scavenging of platinum-group elements by highly reduced metallic liquids, geochemical anomalies associated with the Cretaceous-Tertiary boundary may have a significant terrestrial component even if produced through bolide impact. PMID:17746479

  18. Reconfigurable liquid metal based terahertz metamaterials via selective erasure and refilling to the unit cell level

    NASA Astrophysics Data System (ADS)

    Wang, Jinqi; Liu, Shuchang; Guruswamy, Sivaraman; Nahata, Ajay

    2013-11-01

    We demonstrate a technique for selectively erasing and refilling unit cells of terahertz (THz) metamaterials. The structures are formed by injecting eutectic gallium indium (EGaIn), a liquid metal at room temperature, into microchannels within a polydimethylsiloxane (PDMS) mold fabricated using conventional soft lithography techniques. The thin oxide layer that forms on the surface of EGaIn can be locally dissolved via exposure to hydrochloric acid (HCl) introduced at the surface of the gas permeable PDMS mold. In the absence of the oxide skin, the liquid metal retracts to a position where a stable new oxide layer can be formed, effectively erasing the liquid metal structure in the presence of HCl. After erasing selected structures, EGaIn can be re-injected into microchannels to yield the initial structure. In the case of small unit cells, we show that mechanical pressure can be used to effectively erase individual elements. We use THz time-domain spectroscopy to characterize the distinct transmission properties for each of these different structures.

  19. Fermi-liquid breakdown in the paramagnetic phase of a pure metal.

    PubMed

    Doiron-Leyraud, N; Walker, I R; Taillefer, L; Steiner, M J; Julian, S R; Lonzarich, G G

    2003-10-01

    Fermi-liquid theory (the standard model of metals) has been challenged by the discovery of anomalous properties in an increasingly large number of metals. The anomalies often occur near a quantum critical point--a continuous phase transition in the limit of absolute zero, typically between magnetically ordered and paramagnetic phases. Although not understood in detail, unusual behaviour in the vicinity of such quantum critical points was anticipated nearly three decades ago by theories going beyond the standard model. Here we report electrical resistivity measurements of the 3d metal MnSi, indicating an unexpected breakdown of the Fermi-liquid model--not in a narrow crossover region close to a quantum critical point where it is normally expected to fail, but over a wide region of the phase diagram near a first-order magnetic transition. In this regime, corrections to the Fermi-liquid model are expected to be small. The range in pressure, temperature and applied magnetic field over which we observe an anomalous temperature dependence of the electrical resistivity in MnSi is not consistent with the crossover behaviour widely seen in quantum critical systems. This may suggest the emergence of a well defined but enigmatic quantum phase of matter.

  20. Reconfigurable liquid metal based terahertz metamaterials via selective erasure and refilling to the unit cell level

    SciTech Connect

    Wang, Jinqi; Liu, Shuchang; Nahata, Ajay; Guruswamy, Sivaraman

    2013-11-25

    We demonstrate a technique for selectively erasing and refilling unit cells of terahertz (THz) metamaterials. The structures are formed by injecting eutectic gallium indium (EGaIn), a liquid metal at room temperature, into microchannels within a polydimethylsiloxane (PDMS) mold fabricated using conventional soft lithography techniques. The thin oxide layer that forms on the surface of EGaIn can be locally dissolved via exposure to hydrochloric acid (HCl) introduced at the surface of the gas permeable PDMS mold. In the absence of the oxide skin, the liquid metal retracts to a position where a stable new oxide layer can be formed, effectively erasing the liquid metal structure in the presence of HCl. After erasing selected structures, EGaIn can be re-injected into microchannels to yield the initial structure. In the case of small unit cells, we show that mechanical pressure can be used to effectively erase individual elements. We use THz time-domain spectroscopy to characterize the distinct transmission properties for each of these different structures.