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MOLTEN SALT COMPOSITIONS

Description: A list of fused-salt mixtures which are of importance in molten salt research is presented. The list is a revision and extension of the list published in ORNL CF-57-6-81. The liquidus temperatures given are believed to be within lO C of the correct values. (auth)
Date: June 12, 1958
Creator: Blakely, J.P.
Partner: UNT Libraries Government Documents Department

Wetting of metals and glasses on Mo

Description: The wetting of low melting point metals and Si-Ca-Al-Ti-O glasses on molybdenum has been investigated. The selected metals (Au, Cu, Ag) form a simple eutectic with Mo. Metal spreading occurs under nonreactive conditions without interdiffusion or ridge formation. The metals exhibit low (non-zero) contact angles on Mo but this requires temperatures higher than 1100 C in reducing atmospheres in order to eliminate a layer of adsorbed impurities on the molybdenum surface. By controlling the oxygen activity in the furnace, glass spreading can take place under reactive or nonreactive conditions. We have found that in the glass/Mo system the contact angle does not decrease under reactive conditions. In all cases, adsorption from the liquid seems to accelerate the diffusivity on the free molybdenum surface.
Date: January 8, 2008
Creator: Saiz, Eduardo; Tomsia, Antoni P.; Saiz, Eduardo; Lopez-Esteban, Sonia; Benhassine, Mehdi; de Coninck, Joel et al.
Partner: UNT Libraries Government Documents Department

Pysico-chemical properties of hydrophobic ionic liquids containing1-octylpyridinium, 1-octyl-2-methylpyridinium or1-octyl-4-methylpyridinium cations

Description: This paper reports synthesis of some ionic liquids based on cations 1-octylpyridinium, 1-octyl-2-methylpyridinium or 1-octyl-4-methylpyridinium and anions dicyanamide [N(CN)2]-, bis(trifluoromethylsulfonyl)imide [Tf2N]-, bis(pentafluoroethylsulfonyl)imide [BETI]-, trifluoromethyl sulfonate [TfO]-, nonafluorobutyl sulfonate [NfO]-, tetrafluoroborate [BF4]-, trifluorophenylborate [BF3Ph]- or hexafluoroarsenate [AsF6]-. Melting points, decomposition temperatures, densities, mutual solubilities with water, and viscosities have been measured. Unlike similar ionic liquids containing imidazolium cations, pyridinium ionic liquids studied here are nearly immiscible in water. Viscosities are similar and water content is slightly lower than those for ionic liquids containing imidazolium cations.
Date: September 15, 2006
Creator: Papaiconomou, Nicolas; Salminen, Justin; Lee, Jong-Min & Prausnitz, John M.
Partner: UNT Libraries Government Documents Department

Large melting point hysteresis of Ge nanocrystals embedded inSiO2

Description: The melting behavior of Ge nanocrystals embedded within SiO{sub 2} is evaluated using in situ transmission electron microscopy. The observed melting point hysteresis is large ({+-} 17%) and nearly symmetric about the bulk melting point. This hysteresis is modeled successfully using classical nucleation theory without the need to invoke epitaxy.
Date: May 4, 2006
Creator: Xu, Q.; Sharp, I.D.; Yuan, C.W.; Yi, D.O.; Liao, C.Y.; Glaeser,A.M. et al.
Partner: UNT Libraries Government Documents Department

Morphological, rheological and electrochemical studies ofpoly(ethylene oxide) electrolytes containing fumed silicananoparticles

Description: In this paper, the rheology and crystallization of composite Poly(Ethylene Oxide) (PEO) electrolytes were studied by dynamic mechanical analysis, DSC and polarized light microscopy. The effects of fumed silica nanoparticles on the conductivities of the polymer electrolytes at temperatures above and below their melting point were measured and related to their rheology and crystallization behavior, respectively. The electrolyte/electrode interfacial properties and cycling performances of the composite polymer electrolytes in Li/Li cells are also discussed. The measured electrochemical properties were found to depend heavily on the operational environments and sample processing history.
Date: June 1, 2003
Creator: Xie, Jiangbing; Kerr, John B.; Duan, Robert G. & Han, Yongbong
Partner: UNT Libraries Government Documents Department

CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES

Description: This progress report on the Department of Energy project DE-FG-97FT97263 entitled, ''Catalytic Gasification of Coal Using Eutectic Salt Mixtures,'' covers the period April-September 1998. The specific aims of the project for this period were to identify appropriate eutectic salt mixture catalysts for the gasification of Illinois No.6 coal, evaluate various impregnation or catalyst addition methods to improve catalyst dispersion, and evaluate gasification performance in a bench-scale fixed bed reactor. The project is being conducted jointly by Clark Atlanta University (CAU), the University of Tennessee Space Institute (UTSI) and the Georgia Institute of Technology (Georgia Tech) with CAU as the prime contractor. Several single salt catalysts and binary and ternary eutectic catalysts were investigated at Clark Atlanta University. Physical mixing and incipient wetness methods were investigated as catalyst addition techniques. Gasification was carried out using TGA at CAU and UTSI and with a fixed-bed reactor at UTSI. The results showed better gasification activity in the presence of the catalysts tested. The eutectic salt studies showed clear agreement between the melting points of the prepared eutectics and reported literature values. The order of catalytic activity observed was ternary > binary > single salt. With the soluble single salt catalysts, the incipient wetness method was found to give better results than physical mixing technique. Also, catalyst preparation conditions such as catalyst loading, drying time and temperature were found to influence the gasification rate. Based on the Clark Atlanta University studies on Task 1, the project team selected the 43.5%Li{sub 2}CO{sub 3}-31.5%Na{sub 2}CO{sub 3}-25%K{sub 2}CO{sub 3} ternary eutectic and the 29%Na{sub 2}CO{sub 3}-71%K{sub 2}CO{sub 3} and 2.3%KNO{sub 3}-97.7%K{sub 2}CO{sub 3} binary eutectic for the fixed bed studies at UTSI. The eutectic salts were found to be highly insoluble in aqueous medium. As a result the technique of adding the eutectic to the raw coal ...
Date: October 1, 1998
Partner: UNT Libraries Government Documents Department

CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES

Description: This progress report on the Department of Energy project DE-FG-97FT97263 entitled, ''Catalytic Gasification of Coal Using Eutectic Salt Mixtures'', covers the period April-September 1998. The specific aims of the project for this period were to identify appropriate eutectic salt mixture catalysts for the gasification of Illinois No.6 coal, evaluate various impregnation or catalyst addition methods to improve catalyst dispersion, and evaluate gasification performance in a bench-scale fixed bed reactor. The project is being conducted jointly by Clark Atlanta University (CAU), the University of Tennessee Space Institute (UTSI) and the Georgia Institute of Technology (Georgia Tech) with CAU as the prime contractor. Several single salt catalysts and binary and ternary eutectic catalysts were investigated at Clark Atlanta University. Physical mixing and incipient wetness methods were investigated as catalyst addition techniques. Gasification was carried out using TGA at CAU and UTSI and with a fixed-bed reactor at UTSI. The results showed better gasification activity in the presence of the catalysts tested. The eutectic salt studies showed clear agreement between the melting points of the prepared eutectics and reported literature values. The order of catalytic activity observed was ternary > binary > single salt. With the soluble single salt catalysts, the incipient wetness method was found to give better results than physical mixing technique. Also, catalyst preparation conditions such as catalyst loading, drying time and temperature were found to influence the gasification rate. Based on the Clark Atlanta University studies on Task 1, the project team selected the 43.5%Li{sub 2}CO{sub 3}-31.5%Na{sub 2}CO{sub 3}-25%K{sub 2}CO{sub 3} ternary eutectic and the 29%Na{sub 2}CO{sub 3}-71%K{sub 2}CO{sub 3} and 2.3% KNO{sub 3}-97.7%K{sub 2}CO{sub 3} binary eutectic for the fixed bed studies at UTSI. The eutectic salts were found to be highly insoluble in aqueous medium. As a result the technique of adding the eutectic to the raw ...
Date: April 1, 2000
Partner: UNT Libraries Government Documents Department

CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES

Description: The project, ''Catalytic Gasification of Coal Using Eutectic Salt Mixtures'', is being conducted jointly by Clark Atlanta University (CAU), the University of Tennessee Space Institute (UTSI) and the Georgia Institute of Technology (GT). The aims of the project are to: identify appropriate eutectic salt mixture catalysts for the gasification of Illinois No.6 coal; evaluate various impregnation or catalyst addition methods to improve catalyst dispersion; evaluate effects of major process variables (e.g., temperature, system pressure, etc.) on coal gasification; evaluate the recovery, regeneration and recycle of the spent catalysts in a bench-scale fixed bed reactor; and conduct thorough analysis and modeling of the gasification process to provide a better understanding of the fundamental mechanisms and kinetics of the process. The eutectic catalysts increased gasification rate significantly. The methods of catalyst preparation and addition had significant effect on the catalytic activity and coal gasification. The incipient wetness method gave more uniform catalyst distribution than that of physical mixing for the soluble catalysts resulting in higher gasification rates for the incipient wetness samples. The catalytic activity increased by varying degrees with catalyst loading. The above results are especially important since the eutectic catalysts (with low melting points) yield significant gasification rates even at low temperatures. Among the ternary eutectic catalysts studied, the system 39% Li{sub 2}CO{sub 3}-38.5% Na{sub 2}CO{sub 3}-22.5% Rb{sub 2}CO{sub 3} showed the best activity and will be used for further bench scale fixed-bed gasification reactor in the next period. Based on the Clark Atlanta University studies in the previous reporting period, the project team selected the 43.5% Li{sub 2}CO{sub 3}-31.5% Na{sub 2}CO{sub 3}-25% K{sub 2}CO{sub 3} ternary eutectic and the 29% Na{sub 2}CO{sub 3}-71% K{sub 2}CO{sub 3} binary eutectic for the fixed-bed studies at UTSI during this reporting period. Temperature was found to have a significant effect on the rate ...
Date: April 1, 1999
Partner: UNT Libraries Government Documents Department

Synthesis and casting of a lithium-bismuth compound for an ion-replacement electrorefiner.

Description: The intermetallic compound Li{sub 3}Bi played an integral part in the demonstration of an ion replacement electrorefining method developed at Argonne National Laboratory. The Li{sub 3}Bi compound was generated in a tilt-pour casting furnace using high-purity lithium and bismuth metals as the initial charge. At first, small-scale ({approximately}20 g) experiments were conducted to determine the materials synthesis parameters. In the end, four larger-scale castings (500 g to 1250 g) were completed in a tantalum crucible. The metals were heated slowly to melt the charge, and the formation reaction proceeded vigorously above the melting point of bismuth ({approximately}270 C). For the large-scale melts, the furnace power was temporarily turned off at this point. After several minutes, the tantalum crucible stopped glowing, and the furnace power was turned on. The temperature was then increased to {approximately}1200 C to melt and homogenize the compound, and liquid Li{sub 3}Bi was cast into cold stainless steel molds. Approximately 3.7 kg of Li{sub 3}Bi was generated by this method.
Date: November 23, 1998
Creator: McDeavitt, S. M.
Partner: UNT Libraries Government Documents Department

An Evaluation of Liquidus Temperature as a Function of Waste Loading for a Tank 42 "Sludge Only"/Frit 200 Flowsheet

Description: 'The waste glass produced in the SRS Defense Waste Processing Faiclity (DWPF) process must comply with Waste Acceptance Product Specifications (WAPS) and process control requirements by demonstrating, to a high degree of confidence, that melter feed will produce glass satisfying all quality and processing requirements.'
Date: May 10, 1999
Creator: Peeler, D.
Partner: UNT Libraries Government Documents Department

New Target Results from the FNAL Antiproton Source

Description: Nickel and compressed rhenium powder targets have been installed in the FNAL antiproton source target station. Ni was chosen for its high melting point energy and resistance to stress wave fractures. As well, compressed powdered rhenium segments were constrained by a thin-wall Ti jacket to insure resistance to stress fractures. The {bar p} yield of these new targets is compared with that of copper - the previous standard production target. The target depletion characteristics of nickel and rhenium for a beam intensity of 1.6 x 10{sup 12} protons per pulse are also presented.
Date: January 1, 1992
Creator: O'Day, S.; Bieniosek, F.; Anderson, K. & /Fermilab
Partner: UNT Libraries Government Documents Department

CONSTITUTION OF URANIUM AND THORIUM ALLOYS

Description: A compilation of constitution diagrams of uranium and thorium alloys is presented. The transformation and melting temperatures of the base metal are discussed, followed by the various alloys in alphabetical order. References are included on each alloy. (J.R.D.)
Date: June 1, 1958
Creator: Rough, F.A. & Bauer, A.A.
Partner: UNT Libraries Government Documents Department

Melting of transition metals at high pressure and the influence of liquid frustration. I. The late metals Cu, Ni and Fe

Description: This report focuses on the role that frustration, or preferred liquid local causes ordering, plays in the melting of transition metals. Specifically, Cu, Ni and Fe. It is proposed that for liquids of metals with partially filled d-bands (Ni and Fe) frustration caused by Peierls/Jahn-Teller distortion and pressure-induced s-d electron promotion provides a mechanism for creating and enhancing the stability of local structures. At the most elementary level, liquid structures are essentially impurities that lower the freezing point. In the case of transition metals with partially filled d-bands, the application of pressure induces s-d electron promotion increases the concentration of local structures. This leads to melting slopes for Ni and Fe that are considerably lower than measured for Cu, and lower than for theoretical predictions employing models in which liquid structures are neglected.
Date: March 15, 2007
Creator: Ross, M; Boehler, R & Errandonea, D
Partner: UNT Libraries Government Documents Department

The effect of lattice temperature on surface damage in fused silica optics

Description: We examine the effect of lattice temperature on the probability of surface damage initiation for 355nm, 7ns laser pulses for surface temperatures below the melting point to temperatures well above the melting point of fused silica. At sufficiently high surface temperatures, damage thresholds are dramatically reduced. Our results indicate a temperature activated absorption and support the idea of a lattice temperature threshold of surface damage. From these measurements, we estimate the temperature dependent absorption coefficient for intrinsic silica.
Date: October 31, 2007
Creator: Bude, J; Guss, G; Matthews, M & Spaeth, M L
Partner: UNT Libraries Government Documents Department

Properties of some ionic liquids based on1-methyl-3-octylimidazolium and 4-methyl-N-butylpyridinium cations.

Description: Syntheses are reported for ionic liquids containing 1-methyl-3octylimidazolium and 4-methyl-N-butylpyridinium cations, and trifluoromethansulfonate, dicyanamide, bis(trifluoromethylsulfonyl)imide, and nonafluorobutanesulfonate anions. Densities, melting points and glass transition points, solubility in water as well as polarities have been measured. Ionic liquids based on pyridinium cations exhibit higher melting points, lower solubility in water, and higher polarity than those based on imidazolium cations.
Date: September 29, 2005
Creator: Papaiconomou, Nicolas; Yakelis, Neal; Salminen, Justin; Bergman,Robert & Prausnitz, John M.
Partner: UNT Libraries Government Documents Department

Thermodynamic and kinetic characteristics of variations in shapes of ridges formed on {l_brace}100{r_brace} lithium fluoride surfaces

Description: channels with widths in the range form 5 {mu}m were formed in {l_brace}100{r_brace} surfaces of LiF single crystals by a photolithographic technique. Specimens annealed at or above 0.90 T{mu}m, where T{mu} is the melting point, and then quenched showed the channels and the ridges between them develop rounded profiles. Evolution of these profiles was evaluated for the various channel widths and for interchannel ridge spacings of 5 to 100 {mu}m in terms of: (a) an accepted theoretical model for a surface diffusion controlled process, and (b) a model which assumes that shape changes depend only on the relative energies of attachment of atoms in surface sites with various surface curvatures. Either model is consistent with the experimental observations to within the reproducibility in measurements.
Date: December 1, 1991
Creator: Bullard, J. W.; Glaeser, A. M. & Searcy, A. W.
Partner: UNT Libraries Government Documents Department

Electronic structure effects in liquid water studied by photoelectron spectroscopy and density functional theory

Description: We present valence photoelectron emission spectra of liquid water in comparison with gas-phase water, ice close to the melting point, low temperature amorphous and crystalline ice. All aggregation states have major electronic structure changes relative to the free molecule, with rehybridization and development of bonding and anti-bonding states accompanying the hydrogen bond formation. Sensitivity to the local structural order, most prominent in the shape and splitting of the occupied 3a{sub 1} orbital, is understood from the electronic structure averaging over various geometrical structures, and reflects the local nature of the orbital interaction.
Date: April 29, 2008
Creator: Nordlund, Dennis; Odelius, Michael; Bluhm, Hendrik; Ogasawara, Hirohito; Pettersson, Lars G.M. & Nilsson, Anders
Partner: UNT Libraries Government Documents Department

Lattice effects in the light actinides

Description: The light actinides show a variety of lattice effects that do not normally appear in other regions of the periodic table. The article will cover the crystal structures of the light actinides, their atomic volumes, their thermal expansion behavior, and their elastic behavior as reflected in recent thermal vibration measurements made by neutron diffraction. A discussion of the melting points will be given in terms of the thermal vibration measurements. Pressure effects will be only briefly indicated.
Date: December 1998
Creator: Lawson, A. C.; Cort, B.; Roberts, J. A.; Bennett, B. I.; Brun, T. O.; von Dreele, R. B. et al.
Partner: UNT Libraries Government Documents Department

Assessment of molten-salt solar central-receiver freeze-up and recovery events

Description: Molten salt used as a heat transfer fluid in central-receiver so ar power plants has a high freezing point (430{degrees}F (221{degrees}C)). It is very likely during the life of the plant that the receiver will accidentally freeze up due to equipment malfunction or operator error. Experiments were conducted to measure the effects of a molten salt receiver freeze-up and recovery event and methods to thaw the receiver. In addition, simulated freeze/thaw experiments were conducted to determine what happens when salt freezes and is thawed in receiver tubes and to quantify the damage caused to candidate receiver tube materials. Fourteen tube samples of various materials, diameters and wall thicknesses were tested to destruction. Results of these tests are presented in this paper.
Date: February 1996
Creator: Pacheco, J. E. & Dunkin, S. R.
Partner: UNT Libraries Government Documents Department

Prediction of heat of melting and heat capacity of inorganic liquids by the method of group contributions

Description: Complex salts and salt/oxide combinations are being considered for the immobilization and storage or disposal of hazardous or radioactive wastes. There is very little information concerning such fundamental properties as heat of fusion and heat capacities for many of these inorganic materials. This work focuses on the use of elements or simple functional groups to estimate some of these fundamental thermodynamic properties for a variety of inorganic compounds. The major emphasis will be on properties for a variety of inorganic compounds. The major emphasis will be on properties for which some ancillary information may be easily measured, but which may be very difficult to measure directly. An example of such a property is the heat of fusion (or melting). The melting temperature for most pure materials is relatively easy to measure. However, the actual amount of energy required to liquefy, or conversely, the amount of energy which must be removed to solidify those same materials has not been measured. Similarly, important properties such as heat capacities of liquids are unavailable for many compounds. Such information is essential in the chemical industry and are paramount for chemical engineers if they are to design, build and operate plants and facilities in an economical and efficient manner.
Date: November 17, 1997
Creator: Williams, J. D.; Eakman, J. M. & Montoya, M. M.
Partner: UNT Libraries Government Documents Department

Fabrication of Yb-123 Tapes

Description: While Bi-2223 tapes have been the workhorses of the superconductor industry, their poor performance in applied magnetic fields restrict their use to below 30 K. Melt-processing of Ag-clad Yb-123 PIT tapes offers a simple and scalable technique for fabricating long-length HTS conductors capable of being used at 77 K. Under reduced oxygen partial pressure, the peritectic temperature of Yb-123 is below the melting point of Ag, and this facilitates the adaptation of melt-texturing methods for fabricating these tapes. The effect of melt-processing temperature on current density was also explored; a temperature of 965 C yielded optimal critical current values. The critical current density achieved at 4.2 K was 20,000 A/cm{sup 2}, corresponding to a critical current of 52 A. Based on the above results, an optimal processing zone for melt-processing of Ag-clad Yb-123 tapes was determined. These results hold promise for melt-processing of Ag-clad Yb-123 tapes as an alternative to Bi-2223 PIT technology.
Date: November 15, 2000
Creator: Athur, S.; Balachandran, U. & Salama, K.
Partner: UNT Libraries Government Documents Department