Sample records for eutectic salt mixtures

  1. CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES

    SciTech Connect

    Dr. Yaw D. Yeboah; Dr. Yong Xu; Dr. Atul Sheth; Dr. Pradeep Agrawal

    2001-12-01

    The Gas Research Institute (GRI) estimates that by the year 2010, 40% or more of U.S. gas supply will be provided by supplements including substitute natural gas (SNG) from coal. These supplements must be cost competitive with other energy sources. The first generation technologies for coal gasification e.g. the Lurgi Pressure Gasification Process and the relatively newer technologies e.g. the KBW (Westinghouse) Ash Agglomerating Fluidized-Bed, U-Gas Ash Agglomerating Fluidized-Bed, British Gas Corporation/Lurgi Slagging Gasifier, Texaco Moving-Bed Gasifier, and Dow and Shell Gasification Processes, have several disadvantages. These disadvantages include high severities of gasification conditions, low methane production, high oxygen consumption, inability to handle caking coals, and unattractive economics. Another problem encountered in catalytic coal gasification is deactivation of hydroxide forms of alkali and alkaline earth metal catalysts by oxides of carbon (CO{sub x}). To seek solutions to these problems, a team consisting of Clark Atlanta University (CAU, a Historically Black College and University, HBCU), the University of Tennessee Space Institute (UTSI) and Georgia Institute of Technology (Georgia Tech) proposed to identify suitable low melting eutectic salt mixtures for improved coal gasification. The research objectives of this project were to: Identify appropriate eutectic salt mixture catalysts for coal gasification; Assess agglomeration tendency of catalyzed coal; Evaluate various catalyst impregnation techniques to improve initial catalyst dispersion; Determine catalyst dispersion at high carbon conversion levels; Evaluate effects of major process variables (such as temperature, system pressure, etc.) on coal gasification; Evaluate the recovery, regeneration and recycle of the spent catalysts; and Conduct an analysis and modeling of the gasification process to provide better understanding of the fundamental mechanisms and kinetics of the process.

  2. Structure Property Relationships in Imidazole-based Deep Eutectic Mixtures

    NASA Astrophysics Data System (ADS)

    Terheggen, Logan; Cosby, Tyler; Sangoro, Joshua

    2015-03-01

    Deep eutectic mixtures of levulinic acid with a systematic series of imidazoles are measured by broadband dielectric spectroscopy, differential scanning calorimetry, and Fourier transform infrared spectroscopy to investigate the impact of steric interactions on charge transport and structural dynamics. An enhancement of dc conductivity is found in each of the imidazoles upon the addition of levulinic acid. However, the extent of increase is dependent upon the alkyl substitution on the imidazole ring. These results highlight the importance of molecular structure on hydrogen bonding and charge transport in deep eutectic mixtures.

  3. Anthracene + Pyrene Solid Mixtures: Eutectic and Azeotropic Character

    PubMed Central

    Rice, James W.; Fu, Jinxia; Suuberg, Eric M.

    2010-01-01

    To better characterize the thermodynamic behavior of a binary polycyclic aromatic hydrocarbon mixture, thermochemical and vapor pressure experiments were used to examine the phase behavior of the anthracene (1) + pyrene (2) system. A solid-liquid phase diagram was mapped for the mixture. A eutectic point occurs at 404 K at x1 = 0.22. A model based on eutectic formation can be used to predict the enthalpy of fusion associated with the mixture. For mixtures that contain x1 < 0.90, the enthalpy of fusion is near that of pure pyrene. This and X-ray diffraction results indicate that mixtures of anthracene and pyrene have pyrene-like crystal structures and energetics until the composition nears that of pure anthracene. Solid-vapor equilibrium studies show that mixtures of anthracene and pyrene form solid azeotropes at x1 of 0.03 and 0.14. Additionally, mixtures at x1 = 0.99 sublime at the vapor pressure of pure anthracene, suggesting that anthracene behavior is not significantly influenced by x2 = 0.01 in the crystal structure. PMID:21116474

  4. Charge Transport and Structural Dynamics in Deep Eutectic Mixtures

    NASA Astrophysics Data System (ADS)

    Cosby, Tyler; Holt, Adam; Terheggen, Logan; Griffin, Philip; Benson, Roberto; Sangoro, Joshua

    2015-03-01

    Charge transport and structural dynamics in a series of imidazole and carboxylic acid-based deep eutectic mixtures are investigated by broadband dielectric spectroscopy, dynamic light scattering, 1H nuclear magnetic resonance spectroscopy, calorimetry, and Fourier transform infrared spectroscopy. It is found that the extended hydrogen-bonded networks characteristic of imidazoles are broken down upon addition of carboxylic acids, resulting in an increase in dc conductivity of the mixtures. These results are discussed within the framework of recent theories of hydrogen bonding and proton transport.

  5. The Thermodynamic Analysis of Chemistry Stability of Eutectic Salt Phase Change Materials

    Microsoft Academic Search

    Jun Chen; Jin Wang; Jin Song Liu; Jian Hua Liu

    2009-01-01

    This paper analyses the chemistry stability of eutectic salt phase change materials according to chemical thermodynamic principle, and introduces the methods and steps of thermodynamic calculation and analysis during the process of confecting eutectic salt materials. The paper takes thermodynamic calculation according to the two phase-change materials, Na2CO3-SiO2 and Na2SO4-SiO2. By comparing the relational graph of Gibbs free energy and

  6. Estimated heats of fusion of fluoride salt mixtures suitable for thermal energy storage applications

    SciTech Connect

    Misra, A.K.; Whittenberger, J.D.

    1986-05-01

    The heats of fusion of several fluoride salt mixtures with melting points greater than 973 K were estimated from a coupled analysis of the available thermodynamic data and phase diagrams. Simple binary eutectic systems with and without terminal solid solutions, binary eutectics with congruent melting intermediate phases, and ternary eutectic systems were considered. Several combinations of salts were identified, most notable the eutectics LiF-22CaF/sub 2/ and NaF-60MgF/sub 2/ which melt at 1039 and 1273 K respectively which posses relatively high heats of fusion/gm (greater than 0.7 kJ/g). Such systems would seemingly be ideal candidates for the light weight, high energy storage media required by the thermal energy storage unit in advanced solar dynamic power systems envisioned for the future space missions.

  7. Eutectic Salt Catalyzed Environmentally Benign and Highly Efficient Biginelli Reaction

    PubMed Central

    Azizi, Najmadin; Dezfuli, Sahar; Hahsemi, Mohmmad Mahmoodi

    2012-01-01

    A simple deep eutectic solvent based on tin (II) chloride was used as a dual catalyst and environmentally benign reaction medium for an efficient synthesis of 3,4-dihydropyrimidin-2(1H)-one derivatives, from aromatic and aliphatic aldehydes, 1,3-dicarbonyl compounds, and urea in good-to-excellent yields and short reaction time. This simple ammonium deep eutectic solvent, easily synthesized from choline chloride and tin chloride, is relatively inexpensive and recyclable, making it applicable for industrial applications. PMID:22649326

  8. Development of high temperature transport technology for LiCl-KCl eutectic salt in pyroprocessing

    SciTech Connect

    Lee, Sung Ho; Lee, Hansoo; Kim, In Tae; Kim, Jeong-Guk [Korea Atomic Energy Research Institute, 1045 Daedeok-daaro, Yuseong-gu, Daejeon, 305-353 (Korea, Republic of)

    2013-07-01

    The development of high-temperature transport technologies for molten salt is a prerequisite and a key issue in the industrialization of pyro-reprocessing for advanced fuel cycle scenarios. The solution of a molten salt centrifugal pump was discarded because of the high corrosion power of a high temperature molten salt, so the suction pump solution was selected. An apparatus for salt transport experiments by suction was designed and tested using LiC-KCl eutectic salt. The experimental results of lab-scale molten salt transport by suction showed a 99.5% transport rate (ratio of transported salt to total salt) under a vacuum range of 100 mtorr - 10 torr at 500 Celsius degrees. The suction system has been integrated to the PRIDE (pyroprocessing integrated inactive demonstration) facility that is a demonstrator using non-irradiated materials (natural uranium and surrogate materials). The performance of the suction pump for the transport of molten salts has been confirmed.

  9. Densities of some molten fluoride salt mixtures suitable for heat storage in space power applications

    NASA Technical Reports Server (NTRS)

    Misra, Ajay K.

    1988-01-01

    Liquid densities were determined for a number of fluoride salt mixtures suitable for heat storage in space power applications, using a procedure that consisted of measuring the loss of weight of an inert bob in the melt. The density apparatus was calibrated with pure LiF and NaF at different temperatures. Density data for safe binary and ternary fluoride salt eutectics and congruently melting intermediate compounds are presented. In addition, a comparison was made between the volumetric heat storage capacity of different salt mixtures.

  10. The electrochemical behaviour of ferrocene in deep eutectic solvents based on quaternary ammonium and phosphonium salts

    Microsoft Academic Search

    L. Bahadori; N. S. Abdul Manan; M. H. Chakrabarti; M. A. Hashim; F. S. Mjalli; I. M. Alnashef; M. A. Hussain; C. T. J. Low

    2013-01-01

    The electrochemical behaviour of ferrocene (Fc) is investigated in six different deep eutectic solvents (DESs) formed by means of hydrogen bonding between selected ammonium and phosphonium salts with glycerol and ethylene glycol. Combinations of cyclic voltammetry and chronoamperometry are employed to characterise the DESs. The reductive and oxidative potential limits are reported versus the Fc\\/Fc+ couple. The diffusion coefficient, D,

  11. Cyclic voltammetry of metallic acetylacetonate salts in quaternary ammonium and phosphonium based deep eutectic solvents

    Microsoft Academic Search

    M. H. Chakrabarti; N. P. Brandon; F. S. Mjalli; L. Bahadori; I. M. Al Nashef; M. A. Hashim; M. A. Hussain; C. T. J. Low; V. Yufit

    2013-01-01

    Seven commercially sourced acetylacetonate salts were investigated in deep eutectic solvents (DESs that were prepared from ethylene glycol and trifluoroacetamide hydrogen bond donors) by cyclic voltammetry, to identify electrolytes suitable for future applications in electrochemical energy storage devices. Although the solubilities are low and on the order of 0.02 mol·L-1 for the most soluble salts, some were found to display

  12. Solubility of sodium salts in ammonium-based deep eutectic solvents

    Microsoft Academic Search

    F. S. Ghareh Bagh; F. S. Mjalli; M. A. Hashim; M. K. O. Hadj-Kali; I. M. Alnashef

    2013-01-01

    The solubility of sodium chloride (NaCl), sodium bromide (NaBr), and sodium carbonate (Na2CO3) was measured in nine ammonium-based deep eutectic solvents (DESs). The aim of the study is to assess the potential use of these DESs as solvents and electrolytes for the separation of sodium metal from its salts. The studied DESs were prepared by combining ammonium salts with various

  13. Ionic liquids and deep eutectic mixtures: sustainable solvents for extraction processes.

    PubMed

    Pena-Pereira, Francisco; Namie?nik, Jacek

    2014-07-01

    In recent years, ionic liquids and deep eutectic mixtures have demonstrated great potential in extraction processes relevant to several scientific and technological activities. This review focuses on the applicability of these sustainable solvents in a variety of extraction techniques, including but not limited to liquid- and solid-phase (micro) extraction, microwave-assisted extraction, ultrasound-assisted extraction and pressurized liquid extraction. Selected applications of ionic liquids and deep eutectic mixtures on analytical method development, removal of environmental pollutants, selective isolation, and recovery of target compounds, purification of fuels, and azeotrope breaking are described and discussed. PMID:24811900

  14. Studies of Al-Al 3Ni eutectic mixtures as insertion anodes in rechargeable lithium batteries

    Microsoft Academic Search

    S. Machill; D. Rahner

    1997-01-01

    This contribution will give a short overview of aluminium-nickel eutectic mixture alloys as the anode materials in lithium secondary batteries. These compounds allow to create an alloy matrix of modified grain size with stabilizing properties toward ‘mechanical stressing’ during charge\\/discharge processes of lithium. Several electrochemical techniques have been used to investigate the electrochemical behaviour of these lithium-inserting materials.

  15. Binary eutectics formed between ammonium nitrate and amine salts of 5-nitrotetrazole I. preparation and initial characterization

    Microsoft Academic Search

    K.-Y. Lee; M. D. Coburn

    1983-01-01

    We have found that both the ammonium salt of 5-nitrotetrazole (ANT) and the ethylenediamine salt of 5-nitrotetrazole (ENT) form eutectics with ammonium nitrate (AN). Initial characterization and small-scale sensitivity tests of CO2-balanced AN\\/ANT and AN\\/ENT formulations were performed; it was found that both eutectics were less sensitive in all tests than pure ANT or ENT, respectively. The phase diagrams of

  16. Ionic liquids and deep eutectic solvents in natural products research: mixtures of solids as extraction solvents.

    PubMed

    Dai, Yuntao; van Spronsen, Jaap; Witkamp, Geert-Jan; Verpoorte, Robert; Choi, Young Hae

    2013-11-22

    Mixtures of solid chemicals may become liquid under certain conditions. These liquids are characterized by the formation of strong ionic (ionic liquids) or hydrogen bonds (deep eutectic solvents). Due to their extremely low vapor pressure, they are now widely used in polymer chemistry and synthetic organic chemistry, yet little attention has been paid to their use as extraction solvents of natural products. This review summarizes the preparation of ionic liquids and deep eutectic solvents with natural product components and recent progress in their applications to the extraction and analysis of natural products as well as the recovery of extracted compounds from their extracts. Additionally, various factors affecting extraction features of ionic liquids and deep eutectic solvents, as well as potential useful technologies including microwave and ultrasound to increase the extraction efficiency, are discussed. PMID:24188074

  17. A novel group of quaternary ammonium salts as ionic liquids and deep eutectic solvents

    NASA Astrophysics Data System (ADS)

    Sparrow, Christopher R.

    2011-12-01

    A growing number of non-toxic and biodegradable deep eutectic solvents (DES) have been discovered in recent years. This group encompasses the solidified crystalline material 3-(2-aminopyrimidin-1-yl)propanoate (3-2AP), a primary ammonium cation that is a construct of a typical DES. Synthesis of 3-(2-aminopyrimidin-1-yl)propanoate by quarternerization of the amine in the aromatic ring creates a novel deep eutectic solvent. An additional alteration to the DES construct is observed with the formation of a zwitterion between the positively charged quartenary amine group and the negatively charged carboxylate counter ion. The molecular arrangement, or construct, of a deep eutectic solvent will determine both its structure and application in industry. This report describes the synthesis and characterization of an 80:20 urea/3-2AP eutectic mixture with a melting point of 50°C, nearly 120°C lower than the melting temperature of 3-2AP (172.5°C). A cytotoxicity profile for 3-2AP exposed to A549 bronchoaveolar carcinoma cells revealed an LD50 of 337.65 mug/ml.

  18. Continuous salt precipitation and separation from supercritical water. Part 2. Type 2 salts and mixtures of two salts

    Microsoft Academic Search

    Martin Schubert; Johann W. Regler; Frédéric Vogel

    2010-01-01

    Using a continuously operated laboratory plant for the catalytic hydrothermal gasification of biomass featuring a supercritical water salt separator we investigated the separation performance of three different binary type 2 salt–water mixtures and three ternary salt–water mixtures that consisted either of two type 1 salts or two type 2 salts dissolved in water. It turned out that a concentrated salt

  19. Molecular and ionic diffusion in aqueous - deep eutectic solvent mixtures: probing inter-molecular interactions using PFG NMR.

    PubMed

    D'Agostino, Carmine; Gladden, Lynn F; Mantle, Mick D; Abbott, Andrew P; Ahmed, Essa I; Al-Murshedi, Azhar Y M; Harris, Robert C

    2015-06-01

    Pulsed field gradient (PFG) NMR has been used to probe self-diffusion of molecular and ionic species in aqueous mixtures of choline chloride (ChCl) based deep eutectic solvents (DESs), in order to elucidate the effect of water on motion and inter-molecular interactions between the different species in the mixtures, namely the Ch(+) cation and hydrogen bond donor (HBD). The results reveal an interesting and complex behaviour of such mixtures at a molecular level. In general, it is observed that the hydroxyl protons ((1)H) of Ch(+) and the hydrogen bond donor have diffusion coefficients significantly different from those measured for their parent molecules when water is added. This indicates a clear and significant change in inter-molecular interactions. In aqueous Ethaline, the hydroxyl species of Ch(+) and HBD show a stronger interaction with water as water is added to the system. In the case of Glyceline, water has little effect on both hydroxyl proton diffusion of Ch(+) and HBD. In Reline, it is likely that water allows the formation of small amounts of ammonium hydroxide. The most surprising observation is from the self-diffusion of water, which is considerably higher that expected from a homogeneous liquid. This leads to the conclusion that Reline and Glyceline form mixtures that are inhomogeneous at a microscopic level despite the hydrophilicity of the salt and HBD. This work shows that PFG NMR is a powerful tool to elucidate both molecular dynamics and inter-molecular interactions in complex liquid mixtures, such as the aqueous DES mixtures. PMID:25994171

  20. Zero-gravity growth of a sodium chloride-lithium fluoride eutectic mixture

    NASA Technical Reports Server (NTRS)

    Yue, A. S.; Yeh, C. W.; Yue, B. K.

    1982-01-01

    Continuous and discontinuous lithium fluoride fibers embedded in a sodium chloride matrix were produced in space and on Earth, respectively. The production of continuous fibers in a eutectic mixture was attributed to the absence of convective current in the liquid during solidification in space. Image transmission and optical transmittance measurements of transverse sections of the space-grown and Earth-grown ingots were made with a light microscope and a spectrometer. It was found that better optical properties were obtained from samples grown in space. This was attributed to a better alignment of lithium fluoride fibers along the growth direction.

  1. Loss of Anatomical Landmarks with Eutectic Mixture of Local Anesthetic Cream for Neonatal Male Circumcision

    PubMed Central

    Plank, Rebeca M.; Kubiak, David W.; Abdullahi, Rasak Bamidele; Ndubuka, Nnamdi; Nkgau, Maggie M.; Dapaah-Siakwan, Fredrick; Powis, Kathleen M.; Lockman, Shahin

    2012-01-01

    We report two cases of newborns who developed marked local edema after application of a eutectic mixture of local anesthetic (EMLA) topical anesthetic cream for neonatal male circumcision (NMC). Although local edema and erythema are known potential side effects of EMLA cream, a common anesthetic used for NMC, the loss of landmarks precluding safe NMC has not previously been reported, and is described here. Although we cannot recommend an alternate local anesthetic for neonates with this reaction to EMLA, based on a review of the published data we think that serious systemic adverse events related to EMLA are extremely rare. PMID:23102766

  2. Study on a regeneration process of LiCl-KCl eutectic based waste salt generated from the pyrochemical process

    SciTech Connect

    Eun, H.C.; Cho, Y.Z.; Choi, J.H.; Kim, J.H.; Lee, T.K.; Park, H.S.; Kim, I.T.; Park, G.I. [Nuclear Fuel Cycle Waste Treatment Research Division, Korea Atomic Energy Research Institute, 989-111 Daedeok-Daero, Yuseong-Gu, Daejeon 3054-353 (Korea, Republic of)

    2013-07-01

    A regeneration process of LiCl-KCl eutectic waste salt generated from the pyrochemical process of spent nuclear fuel has been studied. This regeneration process is composed of a chemical conversion process and a vacuum distillation process. Through the regeneration process, a high efficiency of renewable salt recovery can be obtained from the waste salt and rare earth nuclides in the waste salt can be separated as oxide or phosphate forms. Thus, the regeneration process can contribute greatly to a reduction of the waste volume and a creation of durable final waste forms. (authors)

  3. Charge transport and structural dynamics in carboxylic-acid-based deep eutectic mixtures.

    PubMed

    Griffin, Philip J; Cosby, Tyler; Holt, Adam P; Benson, Roberto S; Sangoro, Joshua R

    2014-08-01

    Charge transport and structural dynamics in the 1:2 mol ratio mixture of lidocaine and decanoic acid (LID-DA), a model deep eutectic mixture (DEM), have been characterized over a wide temperature range using broad-band dielectric spectroscopy and depolarized dynamic light scattering. Additionally, Fourier transform infrared spectroscopy measurements were performed to assess the degree of proton transfer between the neutral parent molecules. From our detailed analysis of the dielectric spectra, we have determined that this carboxylic-acid-based DEM is approximately 25% ionic at room temperature. Furthermore, we have found that the characteristic diffusion rate of mobile charge carriers is practically identical to the rate of structural relaxation at all measured temperatures, indicating that fast proton transport does not occur in LID-DA. Our results demonstrate that while LID-DA exhibits the thermal characteristics of a DEM, its charge transport properties resemble those of a protic ionic liquid. PMID:25025600

  4. Some properties of the eutectic reaction of a mixture of bitumen and M. I. N. D. compounds

    Microsoft Academic Search

    Domun

    1977-01-01

    The report describes the probable cause of the eutectic nature of mixtures of a bitumen and M.I.N.D. compound which may form in 11kV joints and boxes. The rheological and dielectric properties of some mixtures as well as those of the parent materials have been measured over the range of service temperature. The dielectric loss factor of a 50\\/50 mixture at

  5. The electrochemical behaviour of ferrocene in deep eutectic solvents based on quaternary ammonium and phosphonium salts.

    PubMed

    Bahadori, Laleh; Manan, Ninie Suhana Abdul; Chakrabarti, Mohammed Harun; Hashim, Mohd Ali; Mjalli, Farouq Sabri; AlNashef, Inas Muen; Hussain, Mohd Azlan; Low, Chee Tong John

    2013-02-01

    The electrochemical behaviour of ferrocene (Fc) is investigated in six different deep eutectic solvents (DESs) formed by means of hydrogen bonding between selected ammonium and phosphonium salts with glycerol and ethylene glycol. Combinations of cyclic voltammetry and chronoamperometry are employed to characterise the DESs. The reductive and oxidative potential limits are reported versus the Fc/Fc(+) couple. The diffusion coefficient, D, of ferrocene in all studied DESs is found to lie between 8.49 × 10(-10) and 4.22 × 10(-8) cm(2) s(-1) (these do not change significantly with concentration). The standard rate constant for heterogeneous electron transfer across the electrode/DES interface is determined to be between 1.68 × 10(-4) and 5.44 × 10(-4) cm s(-1) using cyclic voltammetry. These results are of the same order of magnitude as those reported for other ionic liquids in the literature. PMID:23247115

  6. 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

  7. Molecular and ionic diffusion in aqueous - deep eutectic solvent mixtures: Probing inter-molecular interactions using PFG NMR

    E-print Network

    D'Agostino, Carmine; Gladden, Lynn F.; Mantle, Mick D.; Abbott, Andrew P.; Ahmed, Essa I.; Al-Murshedi, Azhar Y. m.; Harris, Robert C.

    2015-06-02

    Pulsed field gradient (PFG) NMR has been used to probe self-diffusion of molecular and ionic species in aqueous mixtures of choline chloride (ChCl) based deep eutectic solvents (DESs), in order to elucidate the effect of water on motion and inter...

  8. An optimal method for phosphorylation of rare earth chlorides in LiCl-KCl eutectic based waste salt

    NASA Astrophysics Data System (ADS)

    Eun, H. C.; Kim, J. H.; Cho, Y. Z.; Choi, J. H.; Lee, T. K.; Park, H. S.; Park, G. I.

    2013-11-01

    A study on an optimal method for the phosphorylation of rare earth chlorides in LiCl-KCl eutectic waste salt generated the pyrochemical process of spent nuclear fuel was performed. A reactor with a pitched four blade impeller was designed to create a homogeneous mixing zone in LiCl-KCl eutectic salt. A phosphorylation test of NdCl3 in the salt was carried out by changing the operation conditions (operation temperature, stirring rate, agent injection amount). Based on the results of the test, a proper operation condition (450 °C, 300 rpm, 1 eq. of phosphorylation agent) for over a 0.99 conversion ratio of NdCl3 to NdPO4 was determined. Under this condition, multi-component rare earth (La, Ce, Pr, Nd, Sm, Eu, Gd, Y) chlorides were effectively converted into phosphate forms. It was confirmed that the existing regeneration process of LiCl-KCl eutectic waste salt can be greatly improved and simplified through these phosphorylation test results.

  9. A low-temperature heat storage system utilizing mixtures of magnesium salt hydrates and ammonium nitrate

    SciTech Connect

    Vaccarino, C.; Barbaccia, A.; Frusteri, F.; Galli, G.; Maisano, G.

    1985-02-01

    The heat storage system based on mixtures of salt hydrates and anhydrous salts desjribed in previous articles has been applied to Mg(NO/sub 3/)/sub 2/.6H/sub 2/O and MgCI/sub 2/. 6H/sub 2/O (alone or in eutectic mixtures), added with NH/sub 4/NO/sub 3/. Calorimetric measurements showed that in the temperature range 25-60/sup 0/C, Mg(NO/sub 3/). 6H/sub 2/O allows a Thermal Energy Storage (TES) capacity of about 56 kcal/kg (equivalent to 86 kcal/liter), which is slightly lower than the values previously recorded with ammonium alum. When the maximum temperature was lowered to 55/sup 0/ and to 50/sup 0/C, in order to be closer to the peak-efficiency of commercial flat-plate collectors, the best results were obtained, respectively, with Mg(NO/sub 3/)/sub 2/ .6H/sub 2/O and with the eutectic mixture Mg(NO/sub 3/)/sub 2/. 6H/sub 2/O - MgCI/sub 2/. 6H/sub 2/O, both added with NH/sub 4/NO/sub 3/. The mixtures of the aforementioned magnesium salts and ammonium nitrate do not show any significant efficiency reduction after many thermal cycles, and at the present stage of the research, they may be considered the most suitable for obtaining heat storages in the temperature range of commercial solar collectors.

  10. Characterization and comparison of lidocaine-tetracaine and lidocaine-camphor eutectic mixtures based on their crystallization and hydrogen-bonding abilities.

    PubMed

    Gala, Urvi; Chuong, Monica C; Varanasi, Ravi; Chauhan, Harsh

    2015-06-01

    Eutectic mixtures formed between active pharmaceutical ingredients and/or excipients provide vast scope for pharmaceutical applications. This study aimed at the exploration of the crystallization abilities of two eutectic mixtures (EM) i.e., lidocaine-tetracaine and lidocaine-camphor (1:1 w/w). Thermogravimetric analysis (TGA) for degradation behavior whereas modulated temperature differential scanning calorimetry (MTDSC) set in first heating, cooling, and second heating cycles, was used to qualitatively analyze the complex exothermic and endothermic thermal transitions. Raman microspectroscopy characterized vibrational information specific to chemical bonds. Prepared EMs were left at room temperature for 24 h to visually examine their crystallization potentials. The degradation of lidocaine, tetracaine, camphor, lidocaine-tetracaine EM, and lidocaine-camphor EM began at 196.56, 163.82, 76.86, 146.01, and 42.72°C, respectively, which indicated that eutectic mixtures are less thermostable compared to their individual components. The MTDSC showed crystallization peaks for lidocaine, tetracaine, and camphor at 31.86, 29.36, and 174.02°C, respectively (n?=?3). When studying the eutectic mixture, no crystallization peak was observed in the lidocaine-tetracaine EM, but a lidocaine-camphor EM crystallization peak was present at 18.81°C. Crystallization occurred in lidocaine-camphor EM after being kept at room temperature for 24 h, but not in lidocaine-tetracaine EM. Certain peak shifts were observed in Raman spectra which indicated possible interactions of eutectic mixture components, when a eutectic mixture was formed. We found that if the components forming a eutectic mixture have crystallization peaks close to each other and have sufficient hydrogen-bonding capability, then their eutectic mixture is least likely to crystallize out (as seen in lidocaine-tetracaine EM) or vice versa (lidocaine-camphor EM). PMID:25370024

  11. Salt-induced changes of colloidal interactions in critical mixtures

    E-print Network

    Ursula Nellen; Julian Dietrich; Laurent Helden; Shirish Chodankar; Kim Nygard; J. Friso van der Veen; Clemens Bechinger

    2011-04-28

    We report on salt-dependent interaction potentials of a single charged particle suspended in a binary liquid mixture above a charged wall. For symmetric boundary conditions (BC) we observe attractive particle-wall interaction forces which are similar to critical Casimir forces previously observed in salt-free mixtures. However, in case of antisymmetric BC we find a temperature-dependent crossover from attractive to repulsive forces which is in strong contrast to salt-free conditions. Additionally performed small-angle x-ray scattering experiments demonstrate that the bulk critical fluctuations are not affected by the addition of salt. This suggests that the observed crossover can not be attributed alone to critical Casimir forces. Instead our experiments point towards a possible coupling between the ionic distributions and the concentration profiles in the binary mixture which then affects the interaction potentials in such systems.

  12. Application of eutectic ceramic mixtures for the functional components of high temperature SOFC's

    SciTech Connect

    Gerk, C.; Willert-Porada, M.

    1998-07-01

    A novel design for a high temperature SOFC, based on lamellar electrode-electrolyte segments obtained by solidification of an oxidic eutectic melt on an electrolyte substrate is presented. Such composite electrodes contain NiO or MnO - 8Y-ZrO{sub 2} lamellae, which after reduction/oxidation yield electrode-electrolyte lamellae with 1--2 {micro}m width and a vertical dimension of >100 {micro}m, depending upon the amount of eutectic melt solidified on a polycrystalline substrate. The nucleation of the eutectic on a polycrystalline substrate followed by a semi-directional crystallization of the two phases yields a gradient of 3-phase boundaries over the height of such an electrode, with the number of 3-phase boundaries increasing towards the substrate.

  13. A novel deep eutectic solvent-based ionic liquid used as electrolyte for dye-sensitized solar cells

    Microsoft Academic Search

    Huei-Ru Jhong; David Shan-Hill Wong; Chi-Chao Wan; Yung-Yun Wang; Tzu-Chien Wei

    2009-01-01

    We utilize a quaternary ammonium salt-derivative ionic liquid called G.CI which is a eutectic mixture of glycerol and choline iodide as electrolyte for dye-sensitized solar cells. Such eutectic compound belongs to a new series of ionic liquid called deep eutectic solvents (DES), which possess many outstanding features compared to the traditional imidazolium-based ionic liquids including cheap raw materials, simple preparation

  14. Three new polyoxometalate-based hybrids prepared from choline chloride\\/urea deep eutectic mixture at room temperature

    Microsoft Academic Search

    Shi-Ming Wang; Wei-Lin Chen; En-Bo Wang; Yang-Guang Li; Xiao-Jia Feng; Lin Liu

    2010-01-01

    Three new polyoxometalate-based hybrids {[(CH3)3N(CH2)2OH]2(H3O)}[Na2(H2O)6][IMo6O24]·H2O 1 , {Na2[(CH3)3N(CH2)2OH]4}[Al(OH)6Mo6O18]2·8NH2CONH2·4H2O 2 and {Na6(H2O)18[(CH3)3N(CH2)2OH]2(CON2H5)2}[NaMo7O24]2·4NH2CONH2·H2O 3 were successfully synthesized in the choline chloride\\/urea deep eutectic mixture at room temperature. Reactant quantities of water presents in the nonaqueous eutectic mixture solvent may influence the structure of the products. The three compounds are fully characterized by elemental analyses, IR, UV–vis, TG analyses, power X-ray diffraction and

  15. Tailoring supramolecular nanotubes by bile salt based surfactant mixtures.

    PubMed

    Gubitosi, Marta; Travaglini, Leana; di Gregorio, Maria Chiara; Pavel, Nicolae V; Vázquez Tato, José; Sennato, Simona; Olsson, Ulf; Schillén, Karin; Galantini, Luciano

    2015-06-01

    An approach for tailoring self-assembled tubular structures is described. By controlling the relative composition of a two-component surfactant mixture comprising the natural bile salt lithocholate and its bolamphiphilic derivative, it was possible to finely tune the nanotube cross-section of the mixed tubular aggregates that self-associated spontaneously in aqueous solution at pH?12. The diameter was found to vary up to 50?% when the stoichiometric ratio of the two bile salts was changed. The tuning of supramolecular nanochannels with such remarkable precision is of significant interest for technological applications of these materials. PMID:25925079

  16. Absorption characteristics of anions (I-, Br-, and Te2-) into zeolite in molten LiCl-KCl eutectic salt

    NASA Astrophysics Data System (ADS)

    Uozumi, Koichi; Sugihara, Kei; Kinoshita, Kensuke; Koyama, Tadafumi; Tsukada, Takeshi; Terai, Takayuki; Suzuki, Akihiro

    2014-04-01

    The behaviors of anion fission product (FP) elements to be absorbed into zeolite in molten LiCl-KCl eutectic salt were studied using iodine, bromine, and tellurium. First, the type-A zeolite was selected as the most suitable type of zeolite among type-A, type-X, and type-Y zeolites through experiments in which zeolites were heated together with LiCl-KCl-KI salt. As the next step, experiments in which the type-A zeolite was immersed in molten LiCl-KCl salt containing various concentrations of iodine, bromine, or tellurium were performed. The degree of absorption of the anion FP elements was evaluated using the separation factor (SF) value versus chlorine. Although the SF values for iodine and tellurium were higher than 1.0, which meant that these elements were absorbed into the type-A zeolite more intensively than chlorine in the salt, the corresponding value for bromine was approximately 1.0. The effects of coexisting cation FPs were also examined using cesium, strontium, and neodymium, and it was revealed that the SF values for iodine were less than those in the case without cation addition. On the other hand, the SF values for tellurium were not affected by the coexistence of cesium and strontium. Finally, the feasibility of the present pyroprocess flowsheet was evaluated by calculating the inventory of each anion FP in an electrorefiner based on the obtained SF values instead of temporary values for the anion FPs absorption, which were set due to lack of experimental data.

  17. Speciation, physical and electrolytic properties of eutectic mixtures based on CrCl?·6H?O and urea.

    PubMed

    Abbott, Andrew P; Al-Barzinjy, Azeez A; Abbott, Paul D; Frisch, Gero; Harris, Robert C; Hartley, Jennifer; Ryder, Karl S

    2014-05-21

    The electrodeposition of chromium is a technologically vital process, which is principally carried out using aqueous chromic acid. In the current study, it is shown that eutectic mixtures of urea and hydrated chromium(III) chloride provide a liquid which reduces the toxicological issues associated with the current aqueous Cr(VI) electroplating solution. Using EXAFS, mass spectrometry and UV-Vis spectroscopy, it is shown that chromium is present predominantly as a cationic species. Conductivities are higher than for most comparable ionic liquids. It is shown that the electrodeposition of chromium is electrochemically reversible, with a current efficiency much higher than in aqueous electrolytes. Surface tension and density measurements indicate that hole theory is a valid model to describe transport properties in these liquids. Bulk Cr deposits are not macrocrystalline but they are generally crack-free. The deposits have a hardness of 600 ± 10 Vickers and, as such, are comparable to deposits from aqueous systems. PMID:24695874

  18. Effect of antagonistic salt on confined near-critical mixture

    E-print Network

    Faezeh Pousaneh; Alina Ciach

    2014-06-13

    We consider a near-critical binary mixture with addition of antagonistic salt confined between weakly charged and selective surfaces. A mesoscopic functional for this system is developed from a microscopic description by a systematic coarse-graining procedure. The functional reduces to the Landau-Brazovskii functional for amphiphilic systems for sufficiently large ratio between the correlation length in the critical binary mixture and the screening length. Our theoretical result agrees with the experimental observation [Sadakane et.al. J. Chem. Phys. {\\bf 139}, 234905 (2013)] that the antagonistic salt and surfactant both lead to a similar mesoscopic structure. For very small salt concentration $\\rho_{ion}$ the Casimir potential is the same as in a presence of inorganic salt. For larger $\\rho_{ion}$ the Casimir potential takes a minimum followed by a maximum for separations of order of tens of nanometers, and exhibits an oscillatory decay very close to the critical point. For separations of tens of nanometers the potential between surfaces with a linear size of hundreds of nanometers can be of order of $k_BT$. We have verified that in the experimentally studied samples [Sadakane et.al. J. Chem. Phys. {\\bf 139}, 234905 (2013), Leys et.al. Soft Matter {\\bf 9}, 9326 (2013)] the decay length is too small compared to the period of oscillations of the Casimir potential, but the oscillatory force could be observed closer to the critical point.

  19. Deep eutectic solvents based on N-methylacetamide and a lithium salt as suitable electrolytes for lithium-ion batteries.

    PubMed

    Boisset, Aurélien; Menne, Sebastian; Jacquemin, Johan; Balducci, Andrea; Anouti, Mérièm

    2013-12-14

    In this work, we present a study on the physical and electrochemical properties of three new Deep Eutectic Solvents (DESs) based on N-methylacetamide (MAc) and a lithium salt (LiX, with X = bis[(trifluoromethyl)sulfonyl]imide, TFSI; hexafluorophosphate, PF6; or nitrate, NO3). Based on DSC measurements, it appears that these systems are liquid at room temperature for a lithium salt mole fraction ranging from 0.10 to 0.35. The temperature dependences of the ionic conductivity and the viscosity of these DESs are correctly described by using the Vogel-Tammann-Fulcher (VTF) type fitting equation, due to the strong interactions between Li(+), X(-) and MAc in solution. Furthermore, these electrolytes possess quite large electrochemical stability windows up to 4.7-5 V on Pt, and demonstrate also a passivating behavior toward the aluminum collector at room temperature. Based on these interesting electrochemical properties, these selected DESs can be classified as potential and promising electrolytes for lithium-ion batteries (LIBs). For this purpose, a test cell was then constructed and tested at 25 °C, 60 °C and 80 °C by using each selected DES as an electrolyte and LiFePO4 (LFP) material as a cathode. The results show a good compatibility between each DES and LFP electrode material. A capacity of up to 160 mA h g(-1) with a good efficiency (99%) is observed in the DES based on the LiNO3 salt at 60 °C despite the presence of residual water in the electrolyte. Finally preliminary tests using a LFP/DES/LTO (lithium titanate) full cell at room temperature clearly show that LiTFSI-based DES can be successfully introduced into LIBs. Considering the beneficial properties, especially, the cost of these electrolytes, such introduction could represent an important contribution for the realization of safer and environmentally friendly LIBs. PMID:24153449

  20. Heat Capacity Uncertainty Calculation for the Eutectic Mixture of Biphenyl/Diphenyl Ether Used as Heat Transfer Fluid: Preprint

    SciTech Connect

    Gomez, J. C.; Glatzmaier, G. C.; Mehos, M.

    2012-09-01

    The main objective of this study was to calculate the uncertainty at 95% confidence for the experimental values of heat capacity of the eutectic mixture of biphenyl/diphenyl ether (Therminol VP-1) determined from 300 to 370 degrees C. Twenty-five samples were evaluated using differential scanning calorimetry (DSC) to obtain the sample heat flow as a function of temperature. The ASTM E-1269-05 standard was used to determine the heat capacity using DSC evaluations. High-pressure crucibles were employed to contain the sample in the liquid state without vaporizing. Sample handling has a significant impact on the random uncertainty. It was determined that the fluid is difficult to handle, and a high variability of the data was produced. The heat capacity of Therminol VP-1 between 300 and 370 degrees C was measured to be equal to 0.0025T+0.8672 with an uncertainty of +/- 0.074 J/g.K (3.09%) at 95% confidence with T (temperature) in Kelvin.

  1. Protease activation in glycerol-based deep eutectic solvents

    Microsoft Academic Search

    Hua Zhao; Gary A. Baker; Shaletha Holmes

    2011-01-01

    Deep eutectic solvents (DESs) consisting of mixtures of a choline salt (chloride or acetate form) and glycerol are prepared as easily accessible, biodegradable, and inexpensive alternatives to conventional aprotic cation–anion paired ionic liquids. These DES systems display excellent fluidity coupled with thermal stability to nearly 200°C. In this work, the transesterification activities of cross-linked proteases (subtilisin and ?-chymotrypsin), immobilized on

  2. Structure and phase equilibria of mixtures of the complex salt hexadecyltrimethylammonium polymethacrylate, water and different oils

    Microsoft Academic Search

    Juliana Silva Bernardes; Watson Loh

    2008-01-01

    This work reports on phase diagrams for mixtures of a complex salt formed by a cationic surfactant and an oppositely charged polyelectrolyte, hexadecyltrimethylammonium polymethacrylate, in binary mixtures with water and in ternary mixtures containing water and organic solvents of different polarity (‘oils’): decanol, octanol, p-xylene and cyclohexane. The liquid crystalline structures formed were identified by small angle X-ray scattering measurements,

  3. Advanced salt receiver for solar power towers

    SciTech Connect

    Romero, M.; Sanchez, M.; Barrera, G. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Madrid (Spain). Instituto de Energias Renovables/Direccion de Tecnologia; Leon, J.; Sanchez, M. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Tabernas (Spain). Plataforma Solar de Almeria

    1995-11-01

    Falling Film receivers constitute an alternative to the traditional Salt in Tube receivers, widely used and tested in the Central Receiver Systems. This report presents an innovative concept of Internal Film Receiver (IFR), in which a film made of a eutectic mixture of molten salts flows down the back side of a stainless steel panel. The installation with 550 kW nominal power, molten salt inlet temperature 300 C and outlet temperature 550 C is described.

  4. Concentrating aqueous volatile fatty acid salt solutions using a tertiary amine mixture

    E-print Network

    Gaskin, David J

    1997-01-01

    coefficients, [] , measure the selectivity of concentrating calcium salts in the aqueous phase. The distribution coefficients generally vary as follows: [] thus, there is less selectivity as the aliphatic group increases in size. The amine mixture was used...

  5. Separation of the isomers of benzene poly(carboxylic acid)s by quaternary ammonium salt via formation of deep eutectic solvents.

    PubMed

    Hou, Yucui; Li, Jian; Ren, Shuhang; Niu, Muge; Wu, Weize

    2014-11-26

    Because of similar properties and very low volatility, isomers of benzene poly(carboxylic acid)s (BPCAs) are very difficult to separate. In this work, we found that isomers of BPCAs could be separated efficiently by quaternary ammonium salts (QASs) via formation of deep eutectic solvents (DESs). Three kinds of QASs were used to separate the isomers of BPCAs, including the isomers of benzene tricarboxylic acids (trimellitic acid, trimesic acid, and hemimellitic acid) and the isomers of benzene dicarboxylic acids (phthalic acid and isophthalic acid). Among the QASs, tetraethylammonium chloride was found to have the best performance, which could completely separate BPCA isomers in methyl ethyl ketone solutions. It was found that the hydrogen bond forming between QAS and BPCA results in the selective separation of BPCA isomers. QAS in DES was regenerated effectively by the antisolvent method, and the regenerated QAS was reused four times with the same high efficiency. PMID:25351281

  6. Electrochemical studies of kinetic properties of titanium- and vanadium-hydrogen systems at intermediate temperatures using molten salt techniques

    Microsoft Academic Search

    Bor Yann Liaw; G. Deublein; R. A. Huggins

    1995-01-01

    A novel molten salt technique for studying hydrogen transport in Ti an V metals is described. The molten-salt electrolytes were eutectic mixtures of alkali halides dissolved with excess LiH, operating in temperature ranges typically above 300 C, to which electrochemical techniques were difficult to apply conventionally. The authors used the molten salt technique to investigate the thermodynamic properties of the

  7. LOCALIZED CORROSION OF AUSTENITIC STAINLESS STEELEXPOSED TO MIXTURES OF PLUTONIUM OXIDE AND CHLORIDE SALTS

    SciTech Connect

    Zapp, P; Kerry Dunn, K; Jonathan Duffey, J; Ron Livingston, R; Zane Nelson, Z

    2008-11-21

    Laboratory corrosion tests were conducted to investigate the corrosivity of moist plutonium oxide/chloride (PuO{sub 2}/Cl-) salt mixtures on 304L and 316L stainless steel coupons. The tests exposed flat coupons for pitting evaluation and 'teardrop' stressed coupons for stress corrosion cracking (SCC) evaluation at room temperature to various mixtures of PuO{sub 2} and chloride-bearing salts for periods up to 500 days. The two flat coupons were placed so that the solid oxide/salt mixture contacted about one half of the coupon surface. One teardrop coupon was placed in contact with solid mixture; the second teardrop was in contact with the headspace gas only. The mixtures were loaded with nominally 0.5 wt % water under a helium atmosphere. Observations of corrosion ranged from superficial staining to pitting and SCC. The extent of corrosion depended on the total salt concentration and on the composition of the salt. The most significant corrosion was found in coupons that were exposed to 98 wt % PuO{sub 2}, 2 wt % chloride salt mixtures that contained calcium chloride. SCC was observed in two 304L stainless steel teardrop coupons exposed in solid contact to a mixture of 98 wt % PuO{sub 2}, 0.9 wt % NaCl, 0.9 wt % KCl, and 0.2 wt % CaCl{sub 2}. The cracking was associated with the heat-affected zone of an autogenous weld that ran across the center of the coupon. Cracking was not observed in coupons exposed to the headspace gas, nor in coupons exposed to other mixtures with either 0.92 wt% CaCl{sub 2} or no CaCl{sub 2}. The corrosion results point to the significance of the interaction between water loading and the concentration of the hydrating salt CaCl{sub 2} in the susceptibility of austenitic stainless steels to corrosion.

  8. Osmotic distillation with propylene glycol, glycerol and glycerol–salt mixtures

    Microsoft Academic Search

    M. Celere; C. Gostoli

    2004-01-01

    Aqueous solutions of propylene glycol (PG), glycerol and glycerol–salt mixtures are investigated as alternative to calcium chloride, normally employed to concentrate aqueous mixtures by osmotic distillation (OD). These extractants can overcome the problems of corrosion and scaling associated with the use of brines. The proposed extractants are compared in terms of driving force available for mass transfer, flux achievable, viscosity,

  9. Activity coefficients of actinide and rare-earth chlorides in molten LiCl/KCl eutectic salt

    SciTech Connect

    Bechtel, T.B.; Storvick, T.S. [Univ. of Missouri, Columbia, MO (United States). Dept. of Chemical Engineering] [Univ. of Missouri, Columbia, MO (United States). Dept. of Chemical Engineering

    1999-04-01

    Using a numerical Gibbs free-energy minimization technique, the activity coefficients of actinide and rare-earth chlorides in molten LiCl/KCl eutectic at 450 C have been calculated. Laboratory tests of an electrochemical process for separating actinide metals from rare-earth metals in LiCl/KCl solvent at 450 C provided experimental concentration and cathode potential data. The generalized expansion by Wohl was used to express the concentration dependence of the excess Gibbs free energy. The activity coefficients were expressed in terms of the Wohl volume and interaction energy parameters. The Wohl parameters for the activity coefficient expansions were obtained by minimizing the total Gibbs free energy expressed in terms of the experimental mole fractions. This thermodynamic model will be valuable for process design and scale-up calculations.

  10. Study of the aggregation behaviour of egg yolk lecithin/bile salt mixtures by increasing the ionic strength 

    E-print Network

    Madenci, Dilek

    2009-11-25

    This thesis describes a study of the aggregational behaviour of egg yolk lecithin (EYL), a natural lecithin, and bile salt mixtures especially with respect to an increase of the ionic strength of the solvent. Mixtures ...

  11. Food-grade submicrometer particles from salts prepared using ethanol-in-oil mixtures.

    PubMed

    Paques, Jerome P; van der Linden, Erik; Sagis, Leonard M C; van Rijn, Cees J M

    2012-08-29

    A simple method for preparing food-grade particles in the submicrometer range of ethanol soluble salts using ethanol-in-oil (E/O) mixtures is described. Salts CaCl2·2H2O and MgCl2·6H2O were dissolved in ethanol that subsequently was mixed with a medium-chain triglyceride oil phase. It was found that type and concentration of salt have a significant influence on the miscibility of ethanol and oil phase and on the stability of E/O mixtures. The ethanol phase was evaporated from the mixture at elevated temperatures, and salt particles with dimensions in the submicrometer range (6-400 nm) remained suspended in the oil phase. It was found that the concentration of salt and volume fraction of ethanol in MCT oil have a significant influence on the size distribution of salt particles. The size of CaCl2 and MgCl2 submicrometer particles was ascertained by scanning electron microscopy and dynamic light scattering. PMID:22853628

  12. Molecular Dynamics Simulation of the Transport Properties of Molten Transuranic Salt Mixtures

    NASA Astrophysics Data System (ADS)

    Baty, Austin; McIntyre, Peter; Sattarov, Akhdiyor; Sooby, Elizabeth

    2012-10-01

    The Accelerator Research Laboratory at Texas A&M is proposing a revolutionary design for accelerator-driven subcritical fission in molten salt (ADSMS), a system that destroys the transuranic elements in spent nuclear fuel. The transuranics are the most enduring hazard of nuclear power, since they contain high radiotoxicity and have half-lives of a thousand to a million years. The ADSMS core is fueled by a homogeneous chloride-based molten salt mixture containing the chlorides of the transuranics and NaCl. Knowledge of the density, heat capacity, thermal conductivity, etc. of the salt mixtures is needed to accurately model the complex ADSMS system. There is a lack of experimental data on the density and transport properties of such mixtures. Molecular dynamics simulations using polarizable ion potentials are used to determine the density and heat capacity of these melts as a function of temperature. Green-Kubo methods are employed to calculate the electrical conductivity, thermal conductivity, and viscosity of the salt using the outputs of the model. Results for pure molten salt systems are compared to experimental data when possible to validate the potentials used. Here we discuss potential salt systems, their neutronic behavior, and the calculated transport properties.

  13. Distribution behavior of uranium, neptunium, rare-earth elements ( Y, La, Ce, Nd, Sm, Eu, Gd) and alkaline-earth metals (Sr,Ba) between molten LiCl?KCI eutectic salt and liquid cadmium or bismuth

    Microsoft Academic Search

    M. Kurata; Y. Sakamura; T. Hijikata; K. Kinoshita

    1995-01-01

    Distribution coefficients of uranium neptunium, eight rare-earth elements (Y, La, Ce, Pr, Nd, Sm, Eu and Gd) and two alkaline-earth metals (Sr and Ba) between molten LiCl-KCI eutectic salt and either liquid cadmium or bismuth were measured at 773 K. Separation factors of trivalent rare-earth elements to uranium or neptunium in the LiCl-KCl\\/Bi system were by one or two orders

  14. PHYSICAL REVIEW E 84, 051401 (2011) Charged colloids in an aqueous mixture with a salt

    E-print Network

    2011-01-01

    PHYSICAL REVIEW E 84, 051401 (2011) Charged colloids in an aqueous mixture with a salt Ryuichi surface, we predict a precipitation transition induced by a strong preference of hydrophilic ions to water on the surface. In particular, the interaction is much amplified on bridging of wetting layers formed above

  15. A New Reverse Wormlike Micellar System: Mixtures of Bile Salt and Lecithin in Organic Liquids

    E-print Network

    Raghavan, Srinivasa

    A New Reverse Wormlike Micellar System: Mixtures of Bile Salt and Lecithin in Organic Liquids Shih amounts to solutions of the phospholipid lecithin. Previous recipes for reverse wormlike micelles have and promote the longitudinal aggregation of lecithin molecules into reverse micellar chains. The formation

  16. Phase equilibria of toluene\\/heptane with deep eutectic solvents based on ethyltriphenylphosphonium iodide for the potential use in the separation of aromatics from naphtha

    Microsoft Academic Search

    M. A. Kareem; F. S. Mjalli; M. A. Hashim; M. K. O. Hadj-Kali; F. S. Ghareh Bagh; I. M. Alnashef

    2013-01-01

    In this work, the liquid-liquid extraction of toluene from hydrocarbons mixtures (toluene\\/heptane) was investigated using deep eutectic solvents as solvents. Ethyltriphenylphosphonium iodide as a salt with either ethylene glycol or sulfolane as hydrogen-bond donors (HBDs) were utilized for synthesizing six DESs. (Liquid + liquid) equilibria data were determined experimentally for the ternary system (toluene + heptane + DES) at (30,

  17. Use of eutectic mixtures for preparation of monolithic carbons with CO?-adsorption and gas-separation capabilities.

    PubMed

    López-Salas, N; Jardim, E O; Silvestre-Albero, A; Gutiérrez, M C; Ferrer, M L; Rodríguez-Reinoso, F; Silvestre-Albero, J; del Monte, F

    2014-10-21

    With global warming becoming one of the main problems our society is facing nowadays, there is an urgent demand to develop materials suitable for CO2 storage as well as for gas separation. Within this context, hierarchical porous structures are of great interest for in-flow applications because of the desirable combination of an extensive internal reactive surface along narrow nanopores with facile molecular transport through broad "highways" leading to and from these pores. Deep eutectic solvents (DESs) have been recently used in the synthesis of carbon monoliths exhibiting a bicontinuous porous structure composed of continuous macroporous channels and a continuous carbon network that contains a certain microporosity and provides considerable surface area. In this work, we have prepared two DESs for the preparation of two hierarchical carbon monoliths with different compositions (e.g., either nitrogen-doped or not) and structure. It is worth noting that DESs played a capital role in the synthesis of hierarchical carbon monoliths not only promoting the spinodal decomposition that governs the formation of the bicontinuous porous structure but also providing the precursors required to tailor the composition and the molecular sieve structure of the resulting carbons. We have studied the performance of these two carbons for CO2, N2, and CH4 adsorption in both monolithic and powdered form. We have also studied the selective adsorption of CO2 versus CH4 in equilibrium and dynamic conditions. We found that these materials combined a high CO2-sorption capacity besides an excellent CO2/N2 and CO2/CH4 selectivity and, interestingly, this performance was preserved when processed in both monolithic and powdered form. PMID:25255054

  18. Charged colloids in an aqueous mixture with a salt

    E-print Network

    Ryuichi Okamoto; Akira Onuki

    2011-10-20

    We calculate the ion and composition distributions around colloid particles in an aqueous mixture, accounting for preferential adsorption, electrostatic interaction, selective solvation among ions and polar molecules, and composition-dependent ionization. On the colloid surface, we predict a precipitation transition induced by strong preference of hydrophilic ions to water and a prewetting transition between weak and strong adsorption and ionization. These transition lines extend far from the solvent coexistence curve in the plane of the interaction parameter \\chi (or the temperature) and the average solvent composition. The colloid interaction is drastically altered by these phase transitions on the surface. In particular, the interaction is much amplified upon bridging of wetting layers formed above the precipitation line. Such wetting layers can either completely or partially cover the colloid surface depending on the average solvent composition.

  19. Thermal Energy Storage Characteristics of Myristic and Stearic Acids Eutectic Mixture for Low Temperature Heating Applications 1 1 Supported by the Research Fund of Gaziosmanpasa University (No.2003\\/42)

    Microsoft Academic Search

    Ahmet Sari; Kamil Kaygusuz

    2006-01-01

    Stearic acid (67.83°C) and myristic acid (52.32°C) have high melting temperatures that can limit their use as phase change material (PCM) in low temperature solar heating applications such as solar space and greenhouse heating in regard to climatic requirements. However, their melting temperatures can be adjusted to a suitable value by preparing a eutectic mixture of the myristic acid (MA)

  20. Homogeneous eutectic of Pb-Sb

    NASA Technical Reports Server (NTRS)

    Winter, J. M., Jr.

    1977-01-01

    Dendrite free eutectic mixture of Pb-Sb is expected to be superelastic material that can be used in formation of shaped charge liners for industrial explosive metal-forming processes and other applications.

  1. The Effects of Instrumental Touching on Infant Pain Perception and the Effects of Eutectic Mixture of Local Anesthetics (EMLA) on the Reduction of Pain

    PubMed Central

    Kucukoglu, Sibel; Celebioglu, Ayda; Caner, Ibrahim; Ok, Gamze; Maden, Rukiye

    2015-01-01

    Background: Premature infants, who have to spend the first week of their lives in neonatal intensive care units (NICUs), experience pain and stress in numerous cases, and they are exposed to many invasive interventions. The studies have shown that uncontrolled pain experienced during early life has negative and long-term side effects, such as distress, and such experiences negatively affect the development of the central nervous system Objectives: The purpose of the study was to examine the effects of touching on infant pain perception and the effects of eutectic mixture of local anesthetic (EMLA) on the reduction of pain. Patients and Methods: Data for the study were collected between March and August 2012 from the neonatal clinic of a university hospital located in eastern Turkey. The population of the study consisted of premature infants who were undergoing treatment, completed the first month and who were approved for Hepatitis B vaccine. The study consisted of two experimental groups and one control group. Information forms, intervention follow-up forms, and Premature Infant Pain Profile (PIPP) were used to collect the data. EMLA cream was applied on the vastus lateralis muscles of the first experimental group before the vaccination. The second experimental group was vaccinated by imitation (placebo), without a needle tip or medicine. Vaccination was carried out using instrumental touch in this group. A routine vaccination was applied in the control group. Results: Mean pain scores of the group to which EMLA was applied were lower in a statistically significant way (P < 0.05) compared to the pain scores of the other groups. Moreover, it was determined that even though invasive intervention was not applied to the newborns, the touching caused them to feel pain just as in the placebo group (P < 0.005). Conclusions: The results demonstrated that EMLA was an effective method for reducing pain in premature newborns, and the use of instrumental touch for invasive intervention stimulated the pain perception in the newborns. PMID:26199711

  2. Evaluation of Composite Alumina Nanoparticle and Nitrate Eutectic Materials for use in Concentrating Solar Power Plants 

    E-print Network

    Malik, Darren R.

    2010-07-14

    The focus of this research was to create and characterize high temperature alumina and nitrate salt eutectic nanofluids for use in thermal energy storage (TES) systems. The nitrate eutectic was originally used in the TES system demonstrated as part...

  3. Phenothiazine-Salt Mixture, Free Choice, for the Control of the Large Stomach Worm in Range Sheep. 

    E-print Network

    Boughton, I. B.; Hardy, W. T.; Price, D. A.

    1953-01-01

    Phenothiazine-Salt Mixture Free Choice, for the Control of the Large Stomach Worm in Range Sheep An 8-year Study Conducted Under the Naturak Range Conditions of the Edwards Plateau DIGEST An 8-year study conducted under practical range... conditions typical of the Edwards Plateau of Texas indicates that the large stomach worm of sheep can be controlled satisfactorily through the continued use of a 1-to-9 phenothiazine-salt mixture supplied free choice as a method of treatment. Two groups...

  4. Determination of Preferential Interaction Parameters by Multicomponent Diffusion. Applications to Poly(ethylene glycol)-Salt-Water Ternary Mixtures

    E-print Network

    Annunziata, Onofrio

    to Poly(ethylene glycol)-Salt-Water Ternary Mixtures Cong Tan, John G. Albright, and Onofrio Annunziata for lysozyme-salt-water systems using precision Rayleigh inter- ferometry.6,10-13,16 Here, we report; In Final Form: February 13, 2008 Poly(ethylene glycol) (PEG) is a hydrophilic nonionic polymer used in many

  5. A new processing route for cleaner production of biodiesel fuel using a choline chloride based deep eutectic solvent

    Microsoft Academic Search

    A. Hayyan; M. A. Hashim; M. Hayyan; F. S. Mjalli; I. M. Alnashef

    2014-01-01

    In this study, the free fatty acids (FFA) content in acidic crude palm oil (ACPO) was converted to fatty acid methyl esters (FAME) using a choline chloride based deep eutectic solvent (ChCl-DES) for the first time. This DES is composed of a mixture of a hydrogen bond donor (i.e. p-toluenesulfonic acid monohydrate) and a salt (i.e. choline chloride). The pre-treatment

  6. Influence of mixtures of calcium-chelating salts on the physicochemical properties of casein micelles.

    PubMed

    Kaliappan, S; Lucey, J A

    2011-09-01

    Calcium-chelating salts (CCS), such as phosphates and citrates, are often added to milk systems to modify physical properties like heat stability. The objective of this study was to investigate the effect of binary CCS mixtures on the properties of casein (CN) micelles including the distribution of Ca between the soluble and CN-bound states. Six binary CCS mixtures were prepared from 4 different types of CCS [i.e., trisodium citrate (TSC), disodium phosphate (DSP), tetrasodium pyrophosphate (TSPP), and sodium hexameta phosphate (SHMP)] by combining 2 CCS at a time in 5 different proportions (8.3:91.7, 29.2:70.8, 50:50, 70.8:29.2, and 91.7:8.3). Different concentrations of these mixtures (0, 0.1, 0.3, 0.5, and 0.7% wt/wt) were added to milk protein concentrate solutions (5% wt/wt) at pH 5.8. The ability of CCS to disperse CN particles and its interaction with Ca were assessed from turbidity measurements, acid-base titration behavior, and the quantity of CN-bound Ca and inorganic phosphate (Pi). Turbidity and the buffering peak at pH ?5.0 during acid titration decreased with an increasing concentration of CCS. This was due to the chelation of Ca and the dispersion of CN micelles. The presence of TSC in mixtures decreased the amount of CN-bound Ca and Pi; however, the presence of TSPP in mixtures increased CN-bound Ca and Pi. When DSP was present at high proportions in mixtures of CCS, the CN-bound Ca and Pi slightly increased. When SHMP was used in mixtures of CCS, CN-bound Ca and Pi increased with the use of a low proportion of SHMP but decreased when SHMP was used at high proportions in the mixture. Combinations of DSP-TSPP used in the proportions 29.2:70.8, 50:50, and 70.8:29.2 resulted in the gelation of milk protein concentrates when the total CCS concentration was ?0.3%. These results indicated that the type of CCS present in a mixture modified CN properties by various mechanisms, including chelation of Ca, dispersion of CN micelles, and formation of new types of Ca-CCS complexes. The type of interaction between the newly formed Ca-CCS complexes and the dispersed CN depended on the proportion, concentration, and type of CCS present in the mixtures. This information is useful in understanding how mixtures of CCS affect CN properties. PMID:21854899

  7. TRANSPORT PROPERTIES OF MOLTEN-SALT REACTOR FUEL MIXTURES: THE CASE OF Na, Li, Be\\/F AND Li, Be, TH\\/F SALTS

    Microsoft Academic Search

    Victor Ignatiev; Aleksander Merzlyakov; Valery Afonichkin; Vladimir Khokhlov; Aleksander Salyulev

    In this paper we have compiled transport properties information, available, on two types of FLiBe based salt mixtures (Na,Li,Be\\/F and Li,Be,Th\\/F) that are presently of importance in the design of innovative molten-salt burner reactors. Estimated and\\/or experimental values measured (particularly, from prior US and Russian studies, as well our recent studies) are given for the following properties: viscosity, thermal conductivity,

  8. Protease activation in glycerol-based deep eutectic solvents

    PubMed Central

    Zhao, Hua; Baker, Gary A.; Holmes, Shaletha

    2011-01-01

    Deep eutectic solvents (DESs) consisting of mixtures of a choline salt (chloride or acetate form) and glycerol are prepared as easily accessible, biodegradable, and inexpensive alternatives to conventional aprotic cation-anion paired ionic liquids. These DES systems display excellent fluidity coupled with thermal stability to nearly 200 °C. In this work, the transesterification activities of cross-linked proteases (subtilisin and ?-chymotrypsin), immobilized on chitosan, were individually examined in these novel DESs. In the 1:2 molar ratio mixture of choline chloride/glycerol containing 3% (v/v) water, cross-linked subtilisin exhibited an excellent activity (2.9 ?mo l min?1 g?1) in conjunction with a selectivity of 98% in the transesterification reaction of N-acetyl-L-phenylalanine ethyl ester with 1-propanol. These highly encouraging results advocate more extensive exploration of DESs in protease-mediated biotransformations of additional polar substrates and use of DESs in biocatalysis more generally. PMID:21909232

  9. Assessment of a Molten Salt Heat Transfer Fluid in a Parabolic Trough Solar Field

    Microsoft Academic Search

    D. Kearney; U. Herrmann; P. Nava; B. Kelly; R. Mahoney; J. Pacheco; R. Cable; N. Potrovitza; D. Blake; H. Price

    2003-01-01

    An evaluation was carried out to investigate the feasibility of utilizing a molten salt as the heat transfer fluid (HTF) and for thermal storage in a parabolic trough solar field to improve system performance and to reduce the levelized electricity cost. The operating SEGS1 plants currently use a high temperature synthetic oil consisting of a eutectic mixture of biphenyl\\/diphenyl oxide.

  10. Study of Eutectic Formation

    NASA Technical Reports Server (NTRS)

    Wilcox, W. R.

    1985-01-01

    The objectives of this program are to determine the influence of convection on the microstructure of eutectics and to develop a technique for revealing the longitudinal microstructure of the MnBi-Bi eutectic. Both objectives aim at trying to explain the observed influence of space processing on the microstructure of MnBi-Bi. A computer program was developed and used to determine the concentration field in front of a growing lamellar eutectic. From this the deviation of the interfacial concentration from the eutectic composition was calculated as a function of eutectic composition, freezing rate, convection, and lamellar spacing.

  11. Dual salt mixtures in mixed mode chromatography with an immobilized tryptophan ligand influence the removal of aggregated monoclonal antibodies.

    PubMed

    Vajda, Judith; Mueller, Egbert; Bahret, Eva

    2014-04-01

    In downstream processing of monoclonal antibodies, proper aggregate removal is crucial. Mixed mode ligands such as immobilized tryptophan have been developed to satisfy the need for efficient removal of antibody aggregates. However, method development for mixed mode applications is complicated, since protein binding and elution can be modulated by an increased set of parameters. In the current study, we investigate the effect of different dual salt mixtures on mixed mode chromatography using TOYOPEARL MX-Trp-650M resin, with respect to the dynamic binding capacity, resolution and monomer purity of two different humanized immunoglobulins. Binding capacities varying by more than 50% were observed for different salt mixtures. Furthermore, antibody monomer and aggregate resolution deviated by 30% for different salt mixtures and linear gradient elution. Similar trends were obtained using an immobilized carboxymethyl ligand for the same set of experiments, but the overall resolution was lower. Less kosmotropic salt systems emphasize the electrostatic binding of the relatively hydrophobic mAbs and reduce hydrophobic attraction to a selectivity-determining constraint. Kosmotropic salts such as citrate appear to cause dominating hydrophobic interactions in protein adsorption that hinder electrostatic protein-ligand interactions. This effect may depend on the ionic and hydrophobic site distribution of a protein. The data presented here are important for the further improvement of downstream processing of therapeutic monoclonal antibodies. PMID:24421277

  12. CO2 capture from simulated fuel gas mixtures using semiclathrate hydrates formed by quaternary ammonium salts.

    PubMed

    Park, Sungwon; Lee, Seungmin; Lee, Youngjun; Seo, Yongwon

    2013-07-01

    In order to investigate the feasibility of semiclathrate hydrate-based precombustion CO2 capture, thermodynamic, kinetic, and spectroscopic studies were undertaken on the semiclathrate hydrates formed from a fuel gas mixture of H2 (60%) + CO2 (40%) in the presence of quaternary ammonium salts (QASs) such as tetra-n-butylammonium bromide (TBAB) and fluoride (TBAF). The inclusion of QASs demonstrated significantly stabilized hydrate dissociation conditions. This effect was greater for TBAF than TBAB. However, due to the presence of dodecahedral cages that are partially filled with water molecules, TBAF showed a relatively lower gas uptake than TBAB. From the stability condition measurements and compositional analyses, it was found that with only one step of semiclathrate hydrate formation with the fuel gas mixture from the IGCC plants, 95% CO2 can be enriched in the semiclathrate hydrate phase at room temperature. The enclathration of both CO2 and H2 in the cages of the QAS semiclathrate hydrates and the structural transition that results from the inclusion of QASs were confirmed through Raman and (1)H NMR measurements. The experimental results obtained in this study provide the physicochemical background required for understanding selective partitioning and distributions of guest gases in the QAS semiclathrate hydrates and for investigating the feasibility of a semiclathrate hydrate-based precombustion CO2 capture process. PMID:23718261

  13. New synthetic route of polyoxometalate-based hybrids in choline chloride\\/urea eutectic media

    Microsoft Academic Search

    Shi-Ming Wang; Yun-Wu Li; Xiao-Jia Feng; Yang-Guang Li; En-Bo Wang

    2010-01-01

    The deep eutectic solvents synthetic method was initially explored as a facile synthesis route to prepare new polyoxometalate (POM)-based hybrids. Such a method can not only avoid poor solubility, lower yields and the potential explosion, but also act as a new type of noxious, convenient and environmental friendly organic reagents. Using the choline chloride\\/urea eutectic mixture as the deep eutectic

  14. Deep eutectic solvents formed between choline chloride and carboxylic acids: versatile alternatives to ionic liquids.

    PubMed

    Abbott, Andrew P; Boothby, David; Capper, Glen; Davies, David L; Rasheed, Raymond K

    2004-07-28

    Deep Eutectic Solvents (DES) can be formed between a variety of quaternary ammonium salts and carboxylic acids. The physical properties are significantly affected by the structure of the carboxylic acid but the phase behavior of the mixtures can be simply modeled by taking account of the mole fraction of carboxylic acid in the mixture. The physical properties such as viscosity, conductivity, and surface tension of these DES are similar to ambient temperature ionic liquids and insight into the cause of these properties is gained using hole-theory. It is shown that the conductivity and viscosity of these liquids is controlled by ion mobility and the availability of voids of suitable dimensions, and this is consistent with the fluidity of other ionic liquids and molten salts. The DES are also shown to be good solvents for metal oxides, which could have potential application for metal extraction. PMID:15264850

  15. A simple, efficient and environmentally benign synthetic protocol for the synthesis of spirooxindoles using choline chloride-oxalic acid eutectic mixture as catalyst/solvent system.

    PubMed

    Khandelwal, Sarita; Rajawat, Anshu; Tailor, Yogesh Kumar; Kumar, Mahendra

    2014-01-01

    An efficient and environmentally benign domino protocol has been presented for the synthesis of structurally diverse spirooxindoles spiroannulated with pyranopyridopyrimidines, indenopyridopyrimidines, and chromenopyridopyrimidines involving three-component reaction of aminouracils, isatins and cyclic carbonyl compounds in deep eutectic solvent (choline chloride-oxalic acid: 1:1) which acts as efficient catalyst and environmentally benign reaction medium. The present protocol offers several advantages such as operational simplicity with easy workup, shorter reaction times excellent yields with superior atom economy and environmentally benign reaction conditions with the use of cost-effective, recyclable, non-toxic and bio-degradable DES as catalyst/solvent. PMID:25329839

  16. Eutectic composite explosives containing ammonium nitrate

    SciTech Connect

    Stinecipher, M.M.

    1981-01-01

    The eutectic of ammonium nitrate (AN), the ammonium salt of 3,5-dinitro-1,2,4-triazole was prepared and its sensitivity and performance were studied. It was found that this AN formulation was unusual in that it performed ideally at small diameter, which indicated that it was a monomolecular explosive. Sensitivity tests included type 12 impact, Henkin thermal and wedge tests, and performance tests included rate stick/plate dent, cylinder, and aquarium tests. Results were compared with calculations, standard explosives, and another eutectic, ethylendiamine dinitrate (EDD)/AN.

  17. Investigations of neutron characteristics for salt blanket models; integral fission cross section measurements of neptunium, plutonium, americium and curium isotopes

    SciTech Connect

    Novoselov, G. F.; Gavrilov, V. V.; Kuvshinov, M. (Mikhail); Bogdanov, V. M. (Vladimir Mikha?lovich); Maslov, Georgi? Vladimirovich,; Vyachin, V. (Vladimir); Mashnik, S. G. (Stepan G.); Gorelov, V. I. (Vladimir Ivanovich); Fomushkin, E. F.

    2001-01-01

    Neutron characteristics of salt blanket micromodels containing eutectic mixtures of sodium, zirconium and uranium sulphides were measured on FKBN-2M, BIGR and MAKET installations. The effective fission cross sections of neptunium, plutonium, americium and curium isotopes were measured on the neutron spectra formed by micromodels. KEYWORDS: transmutation, minor actinides, fluoride salts, micromodel, critical assembly, neutron spectrum, multiplication coefficient, fission, effective cross section, nuclear track detector, nuclear data library

  18. Nonaromatic hydrotropic cationic ammonium salts as a rheology modifier for an anionic/zwitterionic surfactant mixture.

    PubMed

    Singh, Kulbir; O'Toole, Zachary; McLachlan, Aleisha; Marangoni, D Gerrard

    2014-04-01

    In this article, we report additive-induced micellar growth and rheology modification for mixtures of anionic (sodium dodecyl sulfate, SDS) and zwitterionic (N-alkylated glycine derivative, Empigen BB or EBB) surfactants. Two nonaromatic hydrotropic salts (hexyltrimethylammonium bromide, C6TAB, and/or dibutylenebis(dimethylbutylammonium bromide), 4-4-4) are used as novel additives to induce micellar growth in these systems. Nuclear magnetic resonance (NMR), photon correlation spectroscopy (PCS), transmission electron microscopy (TEM), the Weissenberg effect, and rheology measurements were employed to assess mixed micelle formation, micellar growth, and rheology modifications. Finally, the manner in which the surfactants and hydrotropes self-assemble into aggregates has also been deduced from 2D NMR NOESY measurements. In this study, both hydrotropic ions have been found to contribute to similar structural modifications in the mixed micelles of the anionic and zwitterionic surfactants. However, the extent of the rheology modification in solution is found to be quite different when the gemini hydrotrope (4-4-4) versus the monomeric hydrotrope (C6TAB) is employed. PMID:24625067

  19. Analysis of aqueous solutions by near-infrared spectrometry (NIRS) III. Binary mixtures of inorganic salts in water

    Microsoft Academic Search

    Volker J. Frost; Karl Molt

    1997-01-01

    It is shown that binary mixtures of inorganic salts in aqueous solutions can be analyzed quantitatively by near-infrared spectrometry (NIRS). Each component influences the structure of water by miscellaneous cation\\/anion-OH interactions causing specific effects in the NIR spectra which can be evaluated in a quantitative way. The calibrations described were performed using principle component regression (PCR) and optimised with respect

  20. Phenothiazine-Salt Mixture, Free Choice, for the Control of the Large Stomach Worm in Range Sheep.

    E-print Network

    Boughton, I. B.; Hardy, W. T.; Price, D. A.

    1953-01-01

    Phenothiazine-Salt Mixture Free Choice, for the Control of the Large Stomach Worm in Range Sheep An 8-year Study Conducted Under the Naturak Range Conditions of the Edwards Plateau DIGEST An 8-year study conducted under practical range... Medicine; Texas A. & M. College, College Station, Texas. The several disadvantages associated with dren large flocks of sheep were in part responsible for the establl3lllll~nt of the long-term trial described herein. The disadvantages include labor...

  1. Fundamental Properties of Salts

    SciTech Connect

    Toni Y Gutknecht; Guy L Fredrickson

    2012-11-01

    Thermal properties of molten salt systems are of interest to electrorefining operations, pertaining to both the Fuel Cycle Research & Development Program (FCR&D) and Spent Fuel Treatment Mission, currently being pursued by the Department of Energy (DOE). The phase stability of molten salts in an electrorefiner may be adversely impacted by the build-up of fission products in the electrolyte. Potential situations that need to be avoided, during electrorefining operations, include (i) fissile elements build up in the salt that might approach the criticality limits specified for the vessel, (ii) electrolyte freezing at the operating temperature of the electrorefiner due to changes in the liquidus temperature, and (iii) phase separation (non-homogenous solution). The stability (and homogeneity) of the phases can be monitored by studying the thermal characteristics of the molten salts as a function of impurity concentration. Simulated salt compositions consisting of the selected rare earth and alkaline earth chlorides, with a eutectic mixture of LiCl-KCl as the carrier electrolyte, were studied to determine the melting points (thermal characteristics) using a Differential Scanning Calorimeter (DSC). The experimental data were used to model the liquidus temperature. On the basis of the this data, it became possible to predict a spent fuel treatment processing scenario under which electrorefining could no longer be performed as a result of increasing liquidus temperatures of the electrolyte.

  2. Microbial stability and quality of seasoned cracked green Aloreña table olives packed in diverse chloride salt mixtures.

    PubMed

    Bautista-Gallego, J; Arroyo-López, F N; Romero-Gil, V; Rodríguez-Gómez, F; García-García, P; Garrido-Fernández, A

    2013-11-01

    This work was conducted to determine the effect of the partial replacement of NaCl by KCl and CaCl2 (expressed as percentages, wt/vol) on the microbial stability and physicochemical characteristics of seasoned cracked olives using a simplex centroid mixture design. Neither Enterobacteriaceae nor lactic acid bacteria were found during the 50 days that olive packages were monitored. Therefore, microbial instability was considered due to the growth of yeasts, which were the only detected microorganisms; Saccharomyces cerevisiae and Pichia membranifaciens were the most relevant species. Yeasts decreased during the first 21 to 30 days after packing, but their populations rose to 3.5 log CFU/ml by the end of the storage period, clearly causing product deterioration. The partial substitution of NaCl with the other chloride salts slightly altered the phase of microbial inhibition and regrowth. Most of the quality characteristics were not affected by the use of the alternative salt mixtures, but the pH values and Cl(-) concentrations in brine decreased as the CaCl2 concentration increased. Hence, seasoned cracked table olives can be produced using a lower proportion of NaCl without causing significant changes in the shelf life and product quality, although further detailed studies are necessary to guarantee the stability of products packed with specific salt mixtures. PMID:24215697

  3. Ternary eutectic growth of Ag-Cu-Sb alloy within ultrasonic field

    NASA Astrophysics Data System (ADS)

    Zhai, Wei; Hong, Zhenyu; Wei, Bingbo

    2007-08-01

    The liquid to solid transformation of ternary Ag42.4Cu21.6Sb36 eutectic alloy was accomplished in an ultrasonic field with a frequency of 35 kHz, and the growth mechanism of this ternary eutectic was examined. Theoretical calculations predict that the sound intensity in the liquid phase at the solidification interface increases gradually as the interface moves up from the sample bottom to its top. The growth mode of ( ? + ? + Sb) ternary eutectic exhibits a transition of “divorced eutectic—mixture of anomalous and regular structures—regular eutectic” along the sample axis due to the inhomogeneity of sound field distribution. In the top zone with the highest sound intensity, the cavitation effect promotes the three eutectic phases to nucleate independently, while the acoustic streaming efficiently suppresses the coupled growth of eutectic phases. In the meantime, the ultrasonic field accelerates the solute transportation at the solid-liquid interface, which reduces the solute solubility of eutectic phases.

  4. Directionally solidified ceramic eutectics

    NASA Technical Reports Server (NTRS)

    Ashbrook, R. L.

    1977-01-01

    The aligned structures which result from the directional solidification (DS) of ceramic eutectics are of interest because of their potential for use in electronic devices and as structural materials. Techniques for growing DS ceramic eutectics are briefly discussed. The principles and controlling parameters of DS eutectic growth are described. The criteria for plane-front growth and the effect of growth rate on interlamellar or interfiber spacing are discussed. Examples of the effect of growth parameters on the alignment of the microstructure are given. Examples of the mechanical properties of directionally solidified oxide-oxide ceramics are also cited.

  5. Dissipative crystallization of aqueous mixtures of potassium salts of poly(riboadenylic acid) and poly(ribouridylic acid).

    PubMed

    Okubo, Tsuneo

    2011-10-15

    Dissipative drying patterns of aqueous mixtures of potassium salts of poly(riboadenylic acid) (KPolyA) and poly(ribouridylic acid) (KPolyU) were studied on a cover glass, a watch glass and a glass dish at room temperature. Accumulation of the polymers forming the broad rings near the outside edge and the inner area of the dried film was observed. The fine multiple ring structures formed when the affinity of the polymer with the substrate is strong. Microscopic drying patterns changed drastically depending on the location in the dried film. Microscopic drying patterns were mainly dendritic long rods and sword (halberd)-like rods. They are assigned to the crystals of double-stranded and triple-stranded helices of the A:U and A:2U complexes, respectively. Cross-like drying patterns are also observed originated from the salt-polymer interaction. PMID:21715148

  6. Containerless solidification of acoustically levitated Ni-Sn eutectic alloy

    NASA Astrophysics Data System (ADS)

    Geng, D. L.; Xie, W. J.; Wei, B.

    2012-10-01

    Containerless solidification of Ni-18.7at%Sn eutectic alloy has been achieved with a single-axis acoustic levitator. The temperature, motion, and oscillation of the sample were monitored by a high speed camera. The temperature of the sample can be determined from its image brightness, although the sample moves vertically and horizontally during levitation. The experimentally observed frequency of vertical motion is in good agreement with theoretical prediction. The sample undergoes shape oscillation before solidification finishes. The solidification microstructure of this alloy consists of a mixture of anomalous eutectic plus regular lamellar eutectic. This indicates the achievement of rapid solidification under acoustic levitation condition.

  7. Scientific Correspondence Are Natural Deep Eutectic Solvents the Missing Link in

    E-print Network

    Galis, Frietson

    Scientific Correspondence Are Natural Deep Eutectic Solvents the Missing Link in Understanding and deep eutectic solvents (DES) have been revisited by chemical engineering, because such solvents can replace conventional organic solvents. Mixing salts and/or organic compounds may cause a considerable

  8. Study of eutectic formation

    NASA Technical Reports Server (NTRS)

    Wilcox, W. R.; Eisa, G. F.; Baskaran, V.; Richardson, D. C.

    1984-01-01

    A theory was developed for the influence of convection on the microstructure of lamellar eutectics. Convection is predicted to produce a coarser microstructure, especially at low freezing rates and large volume fractions of the minority phase. Similary convection is predicted to lower the interfacial undercooling, especially at low freezing rates. Experiments using spin-up/spin-down were performed on the Mn-Bi eutectic. This stirring had a dramatic effect on the microstructure, not only making it coarser but at low freezing rates also changing the morphology of the MnBi. The coarsering persisted to moderately high freezing rates. At the lowest freezing rate, vigorous stirring caused the MnBi to be concentrated at the periphery of the ingot and absent along the center. Progress was made on developing a technique for revealing the three-dimensional microstructure of the MnBi eutectic by time-lapse videotaping while etching.

  9. Simple Cloud Chambers Using a Freezing Mixture of Ice and Cooking Salt

    ERIC Educational Resources Information Center

    Yoshinaga, Kyohei; Kubota, Miki; Kamata, Masahiro

    2015-01-01

    We have developed much simpler cloud chambers that use only ice and cooking salt instead of the dry ice or ice gel pack needed for the cloud chambers produced in our previous work. The observed alpha-ray particle tracks are as clear as those observed using our previous cloud chambers. The tracks can be observed continuously for about 20?min, and…

  10. Ion specificity at a low salt concentration in water-methanol mixtures exemplified by a growth of polyelectrolyte multilayer.

    PubMed

    Long, Yunchao; Wang, Tao; Liu, Lvdan; Liu, Guangming; Zhang, Guangzhao

    2013-03-19

    By use of a quartz crystal microbalance with dissipation (QCM-D), we have investigated the specific ion effect on the growth of poly(sodium 2-acrylamido-2-methylpropanesulfonate)/poly(diallyldimethylammonium chloride) multilayer at a salt concentration as low as 2.0 mM in water-methanol mixtures. QCM-D results demonstrate that specific ion effect can be observed in methanol and water-methanol mixtures though it is negligible in water. Moreover, the specific ion effect is amplified as the molar fraction of methanol (xM) increases from 0% to 75% but is weakened again with the further increase of xM from 75% to 100%. Nuclear magnetic resonance measurements reveal that the counterion-polyelectrolyte segment interactions may not account for the observed ion specificity. By extending the Collins' concept of matching water affinities to methanol and water-methanol mixtures, we suggest that the ion-solvent interactions and the resulted counterion-charged group interactions are responsible for the occurrence of the specific ion effect. The conductivity measurements indicate that water and methanol molecules may form complexes, and the change of relative proportion of complexes with the xM causes the amplification or weakening of the specific ion effect. PMID:23425248

  11. Conformational transitions of flexible hydrophobic polyelectrolytes in solutions of monovalent and multivalent salts and their mixtures.

    PubMed

    Trotsenko, Oleksandr; Roiter, Yuri; Minko, Sergiy

    2012-04-10

    Conformations of cationic polyelectrolytes (PEs), a weak poly(2-vinylpyridine) (P2VP) and a strong poly(N-methyl-2-vinylpyridinium iodide) (qP2VP), adsorbed on mica from saline solutions in the presence of counterions of different valences are studied using in situ atomic force microscopy (AFM). Quantitative characteristics of chain conformations are analyzed using AFM images of the adsorbed molecules. The results of the statistical analysis of the chain contour reveal collapse of the PE coils when ionic strength is in a range from tens to hundreds of millimoles per kilogram and re-expansion of the coils with a further increase of ionic strength up to a region of the saturated saline solutions. The competition between monovalent and multivalent counterions simultaneously present in solutions strongly affects conformations of PE chains even at a very small fraction of multivalent counterions. Shrinkage of PE coils is steeper for multivalent counterions than for monovalent counterions. However, the re-expansion is only incremental in the presence of multivalent counterions. Extended adsorbed coils at low salt concentrations and at very high concentrations of monovalent salt exhibit conformation corresponding to a 2D coil with 0.95 fraction of bound segments (segments in "trains") in the regime of diluted surface concentration of the PE. Shrunken coils in the intermediate range of ionic strength resemble 3D-globules with 0.8 fraction of trains. The incrementally re-expanded PE coils at a high ionic strength remain unchanged at higher multivalent salt concentrations up to the solubility limit of the salt. The formation of a strong PE complex with multivalent counterions at high ionic strength is not well understood yet. A speculative explanation of the observed experimental result is based on possible stabilization of the complex due to hydrophobic interactions of the backbone. PMID:22413781

  12. The Electric Conductivity and the Activation Energy of Ionic Migration of Molten Salts and Their Mixtures

    Microsoft Academic Search

    H. Bloom; E. Heymann

    1947-01-01

    The electric conductivity (kappa ), and its variation with temperature, of many molten salts of predominantly ionic character can be represented by a simple exponential equation kappa = const. × e-C\\/RT. Deviations from this relation are sometimes found for partially covalent compounds (e.g. ZnCl2, PbCl2) where constitutional changes may be expected with change of temperature. The activation energy of ionic

  13. Morphology-Conductivity Relationship in Salt-containing Diblock Copolymer/Homopolymer Mixtures

    NASA Astrophysics Data System (ADS)

    Irwin, Matthew; Hickey, Robert

    2015-03-01

    In order to unravel how ion conductivity is affected by material morphology, a model system of polystyrene (PS), poly(ethylene oxide) (PEO), PS-block-PEO, and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) was fabricated and characterized. These pseudo-ternary polymer blends, in which the lithium salt associates nearly exclusively with the ethylene oxide, have the potential to form a variety of morphologies such as lamellae and the three-dimensionally interpenetrating bicontinuous microemulsion by simply changing blend composition. Similar to what has been observed in salt-containing diblock copolymers, both the order-disorder transition (ODT) temperature and the ODT temperature window of these blends increase sharply with salt loading. By modulating the relative volume fraction of the homopolymers in the blends, it was shown that, although less than order-of-magnitude changes in the domain spacing do not appreciably affect ion conductivity, some morphologies can result in significantly better conductivity than others. These results outline what factors matter most when designing polymer electrolytes for applications such as rechargeable lithium metal batteries and proton exchange membranes.

  14. Transdermal delivery from eutectic systems: enhanced permeation of a model drug, ibuprofen

    Microsoft Academic Search

    Paul W Stott; Adrian C Williams; Brian W Barry

    1998-01-01

    The formation of eutectic systems between ibuprofen (ibu) and seven terpene skin penetration enhancers was studied and, by using the eutectic systems as donors, the effects of melting point depression of the delivery system on transdermal delivery were investigated. A range of ibu:terpene binary mixtures were melted together, cooled, and recrystallised. Composition\\/melting point phase diagrams were determined by DSC and

  15. Prediction of deep eutectic solvents densities at different temperatures

    Microsoft Academic Search

    K. Shahbaz; F. S. Mjalli; M. A. Hashim; I. M. Alnashef

    2011-01-01

    Predicting densities of nonconventional solvents like deep eutectic solvents (DESs) as a function of temperature is of considerable importance in the development and design of new processes utilizing these solvents. Because of the nature of bonding existing between the salt and the hydrogen bond donor, conventional methods result in very large deviations. In this study, the density of DESs based

  16. Expansion of solidified lead bismuth eutectic

    NASA Astrophysics Data System (ADS)

    Glasbrenner, H.; Gröschel, F.; Grimmer, H.; Patorski, J.; Rohde, M.

    2005-08-01

    Lead bismuth eutectic (LBE) has been proposed both as spallation target and as coolant in a future accelerator driven system (ADS). Therefore this alloy should be fully characterised and its physical properties should be completely known before use. Experiments on the volumetric expansion of LBE were performed by variation of cooling rates, holding times and different starting temperatures of the melt. X-ray diffraction and optical metallurgical examination on LBE has been carried out in order to clarify the reasons for the volumetric expansion of LBE. Additionally thermal expansion of LBE solid was revealed. The results achieved will be discussed and at the end a model assumption will be given trying to explain the processes taking place to an ideal eutectic mixture.

  17. Charge-transfer (CT) dynamics of iodide salts in tetrahydrofuran (THF) and THF-water mixtures.

    NASA Astrophysics Data System (ADS)

    Bragg, Arthur; Schwartz, Benjamin

    2007-03-01

    We have used the spectral sensitivity of the solvated electron to its local environment to probe counterion and cosolvent effects on ultrafast CT dynamics in THF and THF-water mixtures following 1-photon excitation of the I= CTTS band. We find that dynamics in pure THF are dramatically influenced by the presence of the counterion, such that CTTS-generated electrons associate strongly with nearby cations and recombine negligibly with the geminate iodine radical. Studies in solvent mixtures aim to examine preferential ion solvation according to its effects on CT, focusing on THF-rich mixtures, in which water is thought to preferentially solvate equilibrated electrons. Results demonstrate that electrons are initially introduced into water-deficient regions of these solutions, subsequently hydrating over 10's-100's of picoseconds. Trends in the CT and hydration dynamics of electrons generated near various counterions and in solutions of varied water content are used to develop an understanding of the local solvent environments of these ion pairs.

  18. Conversion of carbon dissolved in iron powder into a mixture of hydrocarbons and acetone by heating with aqueous alkali metal salt solution

    Microsoft Academic Search

    Fuminori Akiyama

    1995-01-01

    Heating of iron powder containing carbon with aqueous alkali metal salt solution at 300°C gave a mixture of C1?C6 hydrocarbons and acetone. Prolonged reaction of the iron powder with aqueous potassium carbonate solution gave larger amounts of hydrocarbons and acetone than the reaction with aqueous potassium hydroxide solution.

  19. Processing eutectics in space

    NASA Technical Reports Server (NTRS)

    Douglas, F. C.; Galasso, F. S.

    1974-01-01

    Experimental work is reported which was directed toward obtaining interface shape control while a numerical thermal analysis program was being made operational. An experimental system was developed in which the solid-liquid interface in a directionally solidified aluminum-nickel eutectic could be made either concave to the melt or convex to the melt. This experimental system provides control over the solid-liquid interface shape and can be used to study the effect of such control on the microstructure. The SINDA thermal analysis program, obtained from Marshall Space Flight Center, was used to evaluate experimental directional solidification systems for the aluminum-nickel and the aluminum-copper eutectics. This program was applied to a three-dimensional ingot, and was used to calculate the thermal profiles in axisymmetric heat flow. The results show that solid-liquid interface shape control can be attained with physically realizable thermal configurations and the magnitudes of the required thermal inputs were indicated.

  20. Effects of heating on salt-occluded zeolite

    SciTech Connect

    Lewis, M.A.; Hash, M.C.; Pereira, C.; Ackerman, J.P.

    1996-05-01

    The electrometallurgical treatment of spent nuclear fuel generates a waste stream of fission products in the electrolyte, LiCl-KCl eutectic salt. Argonne National Laboratory is developing a mineral waste form for this waste stream. The waste form consists of a composite formed by hot pressing salt-occluded zeolite and a glass binder. Pressing conditions must be judiciously chosen. For a given pressure, increasing temperatures and hold times give denser products but the zeolite is frequently converted to sodalite. Reducing the temperature or hold time leads to a porous zeolite composite. Therefore, conditions that affect the thermal stability of salt-occluded zeolite both with and without glass are being investigated in an ongoing study. The parameters varied in this stage of the work were heating time, temperature, salt loading, and glass content. The heat-treated samples were examined primarily by X-ray diffraction. Large variations were found in the rate at which salt-occluded zeolite converted to other phases such as nepheline, salt, and sodalite. The products depended on the initial salt loading. Heating times required for these transitions depended on the procedure and temperature used to prepare the salt-occluded zeolite. Mixtures of glass and zeolite reacted much faster than the pure salt-occluded zeolite and were almost always converted to sodalite.

  1. Prediction of the surface tension of deep eutectic solvents

    Microsoft Academic Search

    K. Shahbaz; F. S. Mjalli; M. A. Hashim; I. M. AlNashef

    2012-01-01

    Surface tension is one of the important deep eutectic solvents (DESs) physical properties which provides considerable information related to the molecular influence on the intensity of interactions in the mixture. Due to the absence of DESs surface tension experimental data, prediction methods of this property become of high importance. In this work, two simple methods for the prediction of DESs

  2. Densities of ammonium and phosphonium based deep eutectic solvents: Prediction using artificial intelligence and group contribution techniques

    Microsoft Academic Search

    K. Shahbaz; S. Baroutian; F. S. Mjalli; M. A. Hashim; I. M. Alnashef

    2012-01-01

    As applications of deep eutectic solvents are growing fast as green alternatives, prediction of physical properties data for such systems becomes a necessity for engineering application designs and new process developments. In this study, densities of three classes of deep eutectic solvents, based on a phosphonium and two ammonium salts, were measured. Two predictive models based on artificial intelligence and

  3. Physicochemical properties of three ionic liquids containing a tetracyanoborate anion and their lithium salt mixtures.

    PubMed

    Sanchez-Ramirez, Nédher; Martins, Vitor L; Ando, Rômulo A; Camilo, Fernanda F; Urahata, Sérgio M; Ribeiro, Mauro C C; Torresi, Roberto M

    2014-07-24

    Given their relevant physicochemical properties, ionic liquids (ILs) are attracting great attention as electrolytes for use in different electrochemical devices, such as capacitors, sensors, and lithium ion batteries. In addition to the advantages of using ILs containing lithium cations as electrolytes in lithium ion batteries, the Li(+) transport in ILs containing the most common anion, bis(trifluoromethanesulfonyl) imide anion ([Tf2N]), is reportedly small; therefore, its contribution to the overall conductivity is also low. In this work, we describe the preparation and characterization of two new and one known IL containing the tetracyanoborate anion ([B(CN)4]) as the anionic species. These ILs have high thermal and chemical stabilities, with almost twice the ionic conductivity of the [Tf2N] ILs and, most importantly, provide a greater role for the Li(+) ion throughout the conductivity process. The experimental ionic conductivity and self-diffusion coefficient data show that the [B(CN)4]-based ILs and their Li(+) mixtures have a higher number of charge carriers. Molecular dynamics simulations showed a weaker interaction between Li(+) and [B(CN)4] than that with [Tf2N]. These results may stimulate new applications for ILs that have good Li(+) transport properties. PMID:24992482

  4. Eutectic freeze crystallization in a new apparatus: the cooled disk column crystallizer

    Microsoft Academic Search

    Frank van der Ham; Marcelo Martins Seckler; Geert Jan Witkamp

    2004-01-01

    Eutectic freeze crystallization (EFC) is a technique for simultaneous crystallization of ice and salt that is energetically more efficient than conventional evaporative crystallization. In this paper, a new type of crystallizer is introduced for simultaneously conducting EFC and separating the ice from the salt crystals, the cooled disk column crystallizer (CDCC). Crystallization is achieved by indirect cooling with wiped disks

  5. Accelerator-driven subcritical fission in molten salt core: Closing the nuclear fuel cycle for green nuclear energy

    NASA Astrophysics Data System (ADS)

    McIntyre, Peter; Assadi, Saeed; Badgley, Karie; Baker, William; Comeaux, Justin; Gerity, James; Kellams, Joshua; McInturff, Al; Pogue, Nathaniel; Phongikaroon, Supathorn; Sattarov, Akhdiyor; Simpson, Michael; Sooby, Elizabeth; Tsvetkov, Pavel

    2013-04-01

    A technology for accelerator-driven subcritical fission in a molten salt core (ADSMS) is being developed as a basis for the destruction of the transuranics in used nuclear fuel. The molten salt fuel is a eutectic mixture of NaCl and the chlorides of the transuranics and fission products. The core is driven by proton beams from a strong-focusing cyclotron stack. This approach uniquely provides an intrinsically safe means to drive a core fueled only with transuranics, thereby eliminating competing breeding terms.

  6. Accelerator-driven subcritical fission in molten salt core: Closing the nuclear fuel cycle for green nuclear energy

    SciTech Connect

    McIntyre, Peter; Assadi, Saeed; Badgley, Karie; Baker, William; Comeaux, Justin; Gerity, James; Kellams, Joshua; McInturff, Al; Pogue, Nathaniel; Sattarov, Akhdiyor; Sooby, Elizabeth; Tsvetkov, Pavel [Dept. of Physics, Texas A and M University, College Station, TX 77843 and Dept. of Nuclear Engineering, Texas A and M University, College Station, TX 77843 (United States); Phongikaroon, Supathorn; Simpson, Michael [Dept. of Chemical Engineering, University of Idaho, Idaho Falls ID 83402 (United States)

    2013-04-19

    A technology for accelerator-driven subcritical fission in a molten salt core (ADSMS) is being developed as a basis for the destruction of the transuranics in used nuclear fuel. The molten salt fuel is a eutectic mixture of NaCl and the chlorides of the transuranics and fission products. The core is driven by proton beams from a strong-focusing cyclotron stack. This approach uniquely provides an intrinsically safe means to drive a core fueled only with transuranics, thereby eliminating competing breeding terms.

  7. Processing eutectics in space

    NASA Technical Reports Server (NTRS)

    Douglas, F. C.; Galasso, S. F.

    1975-01-01

    The investigations of directional solidification have indicated the necessity of establishing a secure foundation in earth-based laboratory processing in order to properly assess low-gravity processing. Emphasis was placed on evaluating the regularity of microstructure of the rod-like eutectic Al-Al3Ni obtained under different conditions of growth involving the parameters of thermal gradient, solidification rate, and interfacial curvature. In the case of Al-Al3Ni, where the Al3Ni phase appears as facets rods, solidification rate was determined to be a controlling parameter. Zone melting of thin eutectic films showed that for films of the order of 10 to 20 micrometers thick, the extra surface energy appears to act to stabilize a regular microstructure. The results suggest that the role of low-gravity as provided in space-laboratory processing of materials is to be sought in the possibility of generating a higher thermal gradient in the solidifying ingot for a given power input-output arrangement than can be obtained under normal one-g processes.

  8. Intergranular tellurium cracking of nickel-based alloys in molten Li, Be, Th, U/F salt mixture

    NASA Astrophysics Data System (ADS)

    Ignatiev, Victor; Surenkov, Alexander; Gnidoy, Ivan; Kulakov, Alexander; Uglov, Vadim; Vasiliev, Alexander; Presniakov, Mikhail

    2013-09-01

    In Russia, R&D on Molten Salt Reactor (MSR) are concentrated now on fast/intermediate spectrum concepts which were recognized as long term alternative to solid fueled fast reactors due to their attractive features: strong negative feedback coefficients, easy in-service inspection, and simplified fuel cycle. For high-temperature MSR corrosion of the metallic container alloy in primary circuit is the primary concern. Key problem receiving current attention include surface fissures in Ni-based alloys probably arising from fission product tellurium attack. This paper summarizes results of corrosion tests conducted recently to study effect of oxidation state in selected fuel salt on tellurium attack and to develop means of controlling tellurium cracking in the special Ni-based alloys recently developed for molten salt actinide recycler and tranforming (MOSART) system. Tellurium corrosion of Ni-based alloys was tested at temperatures up to 750 °C in stressed and unloaded conditions in molten LiF-BeF2 salt mixture fueled by about 20 mol% of ThF4 and 2 mol% of UF4 at different [U(IV)]/[U(III)] ratios: 0.7, 4, 20, 100 and 500. Following Ni-based alloys (in mass%): HN80?-VI (Mo—12, Cr—7.6, Nb—1.5), HN80??Y (Mo—13, Cr—6.8, Al—1.1, Ti—0.9), HN80??W (Mo—9.4, Cr—7.0, Ti—1.7, W—5.5) and ??-721 (W—25.2, Cr—5.7, Ti—0.17) were used for the study in the corrosion facility. If the redox state the fuel salt is characterized by uranium ratio [U(IV)]/[U(III)] < 1 the alloys' specimens get a more negative stationary electrode potential than equilibrium electrode potentials of some uranium intermetallic compounds and alloys with nickel and molybdenum. This leads to spontaneous behavior of alloy formation processes on the specimens' surface and further diffusion of uranium deep into the metallic phase. As consequence of this films of intermetallic compounds and alloys of nickel, molybdenum, tungsten with uranium are formed on the alloys specimens' surface, and intergranular corrosion does not take place. In the fuel salt with [U(IV)]/[U(III)] = 4-20 the potentials of uranium alloy formation with the main components of the tested alloys are not reached, that's why alloys and intermetallic compounds are not formed on the surface of the investigated chromium-nickel alloys. Under such conditions any intergranular tellurium corrosion of the selected alloys does not occur. In the fuel salt with [U(IV)/]/[U(III)] = 100 the potentials of uranium alloy formation with the main components of the tested alloys are not also reached. Under such redox conditions any traces intergranular tellurium IGC on the HN80MTY and H80M-VI alloys specimens are not found. Certain signs of incipient IGC in the form of tellurium presence on the grain boundaries in the HN80MTB and EM-721 alloys surface layer and formation of not too deep cracks on HN80MTB alloy surface were revealed at [U(IV)/]/[U(III)] = 100. With this uranium ratio in the presence of corrosion products on the surface of all of the alloys films, containing tellurium, metals of the construction alloys and carbon, are formed. In the melt with [U(IV)]/[U(III)] = 500 in all of the alloys tested the tellurium IGC took place. The HN80MTY alloy shows the maximum resistance to tellurium IGC. The intensity of tellurium IGC of the alloy (the K parameter) is by 3-5 times lower as compared to other alloys. The EM-721 alloy has the minimal resistance to tellurium IGC (K = 9200 pc m/cm, the depth of cracks is up to 434 ?m). The studies have shown, that the intensity of the nickel alloys IGC is controlled by the [U(IV)]/[U(III)] ratio, and its dependence on this parameter is of threshold character. Providing the uranium ratio value's monitoring and regulation, it is possible to control the tellurium corrosion and in such a way to eliminate IGC completely or to minimize its value. The alloys strength characteristics and their structure were changed insignificantly after testing within the [U(IV)]/[U(III)] range from 0.7 t? 100. The changes a

  9. Heat transfer measurements in a forced convection loop with two molten-fluoride salts: LiF--BeF--ThF--UF and eutectic NaBF--NaF

    Microsoft Academic Search

    M. D. Silverman; W. R. Huntley; H. E. Robertson

    1976-01-01

    Heat transfer coefficients were determined experimentally for two molten-fluoride salts (LiF-BeF-ThF-UF (72-16-12-0.3 mole %) and NaBF-NaF (92-8 mole %) proposed as the fuel salt and coolant salt, respectively, for molten-salt breeder reactors. Information was obtained over a wide range of variables, with salt flowing through 12.7-mm-OD (0.5-in.) Hastelloy N tubing in a forced convection loop (FCL-2b). Satisfactory agreement with the

  10. Reactive dye removal in dye\\/salt mixtures by nanofiltration membranes containing vinylsulphone dyes: effects of feed concentration and cross flow velocity

    Microsoft Academic Search

    Ismail Koyuncu

    2002-01-01

    In this study, DS5 DK type nanofiltration membranes were tested to recycle the reactive dye bath effluents. Reactive black 5 (RB5), reactive orange 16 (RO16), reactive blue 19 (RB19) and NaCl were used in the experiments to prepare the synthetic dye and salt mixtures. Effects of feed concentration, pressure and cross flow velocity on the permeate flux and color removal

  11. Distribution behavior of plutonium and americium in LiCl–KCl eutectic\\/liquid cadmium systems

    Microsoft Academic Search

    Y Sakamura; O Shirai; T Iwai; Y Suzuki

    2001-01-01

    The thermodynamics of plutonium and americium in LiCl–KCl eutectic\\/liquid cadmium systems was studied with interest in the oxidation state of americium in the salt phase. The standard potential of plutonium vs. the Ag\\/AgCl (1 wt% AgCl) electrode, E0Pu\\/Pu(III), in the LiCl–KCl eutectic was measured in the temperature range of 400–500°C and given by the equation with a standard deviation, ?=0.0009

  12. Influence of cholic acid on phase transition, rheological behavior, and microstructures of salt-free catanionic surfactant mixtures.

    PubMed

    Liu, Changcheng; Hao, Jingcheng

    2010-04-01

    The influence of a biosurfactant, cholic acid (CA), on the phase transition, microstructure, and rheological properties of two salt-free catanionic surfactant systems, (i) tetradecyltrimethylammonium laurate (TTAL) vesicular solution and (ii) a mixture solution of tetradecyltrimethylammonium hydroxide (TTAOH)/lauric acid (LA)/H(2)O, was investigated. The TTAL vesicular system remains homogeneous at 25 degrees C up to 9.8 mmol.L(-1) CA. At low concentrations of CA, the addition of CA causes a decrease in the viscosity of TTAL vesicular solutions. Upon further addition, the viscosity increases. When LA is gradually substituted by CA in the TTAOH/LA/H(2)O system with equimolar TTAOH and LA to form the TTAOH/(CA + LA)/H(2)O system, the influence of the molar fraction of CA, x = n(CA)/(n(LA) + n(CA)), on the phase transition and rheological behavior was also investigated. With increasing x, the system changes from a birefringent L(alpha) phase of equimolar TTAOH and LA into an L(1)/L(alpha) double-phase, and a single L(1) phase. In the birefringent L(alpha) phase of x = 0.2, cryo-TEM observations demonstrate that vesicles and tube-like and branched tube structures coexist, indicating that the unique structure of CA has a significant influence on the phase transformations of the mixtures. At higher x value, x = 0.5, a dilute solution was obtained, with a lower viscosity comparable to water. However, at x from 0.25 to 0.5, the system exhibits characteristic worm-like micelles with shearing thinning behavior at low and high shear rates but a Newtonian fluid behavior at intermediate shear rate range. At x = 0.2, the sample separates into two phases. The upper phase also shows shear thinning behavior and a narrow plateau at intermediate shear rate. At x < 0.2, the system exhibits similar rheological behavior to the original TTAL vesicular solution. For comparison, an investigation of the cetyltrimethylammonium hydroxide (CTAOH)/LA/H(2)O system with long chain cationic surfactant is also reported. The results of these studies may provide a better understanding of biological membranes and the effects of biosurfactants on surfactant phase transitions. PMID:20225846

  13. Using deep eutectic solvents to electrodeposit CoSm films and nanowires

    Microsoft Academic Search

    P. Cojocaru; L. Magagnin; E. Gomez; E. Vallés

    2011-01-01

    A Deep Eutectic Solvent of 1 chlorine chloride: 2 urea eutectic mixture at 70°C has been tested as useful to electrodeposit both magnetic SmCo films and nanowires. Galvanostatic deposition allows obtaining homogeneous deposits over metallic substrate with variable composition as a function of the current density applied. The deposits obtained at 0.5–1.5mAcm?2 were uniform and they correspond to a cobalt

  14. Solvatochromic probe behavior within choline chloride-based deep eutectic solvents: effect of temperature and water.

    PubMed

    Pandey, Ashish; Pandey, Siddharth

    2014-12-18

    Deep eutectic solvents (DESs) have shown potential as promising environmentally friendly alternatives to conventional solvents. Many common and popular DESs are obtained by simply mixing a salt and a H-bond donor. Properties of such a DES depend on its constituents. Change in temperature and addition of water, a benign cosolvent, can change the physicochemical properties of DESs. The effect of changing temperature and addition of water on solvatochromic probe behavior within three DESs formed from choline chloride combined with 1,2-ethanediol, glycerol, and urea, respectively, in 1:2 mol ratios termed ethaline, glyceline, and reline is presented. Increase in temperature results in reduced H-bond donating acidity of the DESs. Dipolarity/polarizability and H-bond accepting basicity do not change with changing temperature of the DESs. The response of the fluorescence probe pyrene also indicates a decrease in the polarity of the DESs as temperature is increased. Addition of water to DES results in increased dipolarity/polarizability and a decrease in H-bond accepting basicity. Except for pyrene, solvatochromic probes exhibit responses close to those predicted from ideal-additive behavior with slight preferential solvation by DES within the aqueous mixtures. Pyrene response reveals significant preferential solvation by DES and/or the presence of solvent-solvent interactions, especially within aqueous mixtures of ethaline and glyceline, the DESs constituted of H-bond donors with hydroxyl functionalities. FTIR absorbance and Raman spectroscopic measurements of aqueous DES mixtures support the outcomes from solvatochromic probe responses. Aqueous mixtures of ethaline and glyceline possess relatively more interspecies H-bonds as compared to aqueous mixtures of reline, where interstitial accommodation of water within the reline molecular network appears to dominate. PMID:25418894

  15. Applications of molten salts in plutonium processing

    SciTech Connect

    Bowersox, D.F.; Christensen, D.C.; Williams, J.D.

    1987-01-01

    Plutonium is efficiently recovered from scrap at Los Alamos by a series of chemical reactions and separations conducted at temperatures ranging from 700 to 900/sup 0/C. These processes usually employ a molten salt or salt eutectic as a heat sink and/or reaction medium. Salts for these operations were selected early in the development cycle. The selection criteria are being reevaluated. In this article we describe the processes now in use at Los Alamos and our studies of alternate salts and eutectics.

  16. Treatment of textile wastewaters using Eutectic Freeze Crystallization.

    PubMed

    Randall, D G; Zinn, C; Lewis, A E

    2014-01-01

    A water treatment process needs to recover both water and other useful products if the process is to be viewed as being financially and environmentally sustainable. Eutectic Freeze Crystallization (EFC) is one such sustainable water treatment process that is able to produce both pure ice (water) and pure salt(s) by operating at a specific temperature. The use of EFC for the treatment of water is particularly useful in the textile industry because ice crystallization excludes all impurities from the recovered water, including dyes. Also, EFC can produce various salts with the intention of reusing these salts in the process. This study investigated the feasibility of EFC as a treatment method for textile industry wastewaters. The results showed that EFC can be used to convert 95% of the wastewater stream to pure ice (98% purity) and sodium sulfate. PMID:25116506

  17. Fluoride salts and container materials for thermal energy storage applications in the temperature range 973 to 1400 K

    NASA Technical Reports Server (NTRS)

    Misra, Ajay K.; Whittenberger, J. Daniel

    1987-01-01

    Multicomponent fluoride salt mixtures were characterized for use as latent heat of fusion heat storage materials in advanced solar dynamic space power systems with operating temperatures in the range of 973 to 1400 K. The melting points and eutectic composition for many systems with published phase diagrams were verified, and several new eutectic compositions were identified. Additionally, the heats of fusion of several binary and ternary eutectics and congruently melting intermediate compounds were measured by differential scanning calorimetry. The extent of corrosion of various metals by fluoride melts was estimated from thermodynamic considerations, and equilibrium conditions inside a containment vessel were calculated as functions of the initial moisture content of the salt and free volume above the molten salt. Preliminary experimental data on the corrosion of commercial, high-temperature alloys in LiF-19.5CaF2 and NaF-27CaF2-36MgF2 melts are presented and compared to the thermodynamic predictions.

  18. Fluoride salts and container materials for thermal energy storage applications in the temperature range 973 - 1400 K

    NASA Technical Reports Server (NTRS)

    Misra, Ajay K.; Whittenberger, J. Daniel

    1987-01-01

    Multicomponent fluoride salt mixtures were characterized for use as latent heat of fusion heat storage materials in advanced solar dynamic space power systems with operating temperatures in the range of 973 to 1400 K. The melting points and eutectic composition for many systems with published phase diagrams were verified, and several new eutectic compositions were identified. Additionally, the heats of fusion of several binary and ternary eutectics and congruently melting intermediate compounds were measured by differential scanning calorimetry. The extent of corrosion of various metals by fluoride melts was estimated from thermodynamic considerations, and equilibrium conditions inside a containment vessel were calculated as functions of the initial moisture content of the salt and free volume above the molten salt. Preliminary experimental data on the corrosion of commercial, high-temperature alloys in LiF-19.5CaF2 and NaF-27CaF2-36MgF2 melts are presented and compared to the thermodynamic predictions.

  19. Structure-property relationships in eutectic composites

    NASA Technical Reports Server (NTRS)

    Hertzberg, R. W.

    1976-01-01

    The preparation of a composite material of eutectic composition directly from the molten state is investigated. The manufacture of eutectic composites by unidirectional solidification is reviewed, and it is shown how two-phase composite structures of given relative volume fraction can be produced with a range of particle sizes. Crystallographic relationships and the thermal stability of interfaces in controlled eutectic structures are examined, the mechanical behavior of aligned eutectic microstructures is discussed, and characteristics of eutectic composites having mechanical properties of engineering significance are evaluated. Specific properties of the Ni-Nb eutectic alloy are reviewed to demonstrate the effect of structure control (through directional solidification) on the mechanical response of a eutectic composite. It is noted that unidirectionally solidified eutectic composites possess highly aligned and thermally stable microstructures and also exhibit excellent combinations of strength and ductility to very high temperature levels.

  20. Fluoride salts as phase change materials for thermal energy storage in the temperature range 1000-1400 K

    Microsoft Academic Search

    Ajay K. Misra

    1988-01-01

    Eutectic compositions and congruently melting intermediate compounds in binary and ternary fluoride salt systems were characterized for potential use as latent heat of fusion phase change materials to store thermal energy in the temperature range 1000-1400 K. The melting points and eutectic compositions for many systems with published phase diagrams were experimentally verified and new eutectic compositions having melting points

  1. Novel mouse model of combined hyperlipidemia associated with steatosis and liver injury by a single-dose intragastric administration of schisandrin B/cholesterol/bile salts mixture.

    PubMed

    Pan, Si-Yuan; Jia, Zhan-Hong; Zhang, Yi; Yu, Qing; Wang, Xiao-Yan; Sun, Nan; Zhu, Pei-Li; Yu, Zhi-Ling; Ko, Kam-Ming

    2013-01-01

    Hyperlipidemia is referred to as hypercholesterolemia, hypertriglyceridemia, or both in combined hyperlipidemia. Here, a novel mouse model of combined hyperlipidemia is described. Mice were orally given a single dose of a modeling agent (MA) made of a mixture of schisandrin B/cholesterol/bile salts (1/2/0.5 g/kg) suspended in olive oil. MA treatment increased serum triglycerides (TG) and total cholesterol (TC) (up to 422% and 100% at 12 - 96 h post-treatment, respectively) and hepatic TG and TC (up to 220% and 26%, respectively) in a time- and dose-dependent manner, associated with elevation of high-density lipoprotein and low-density lipoprotein levels. Serum alanine/aspartate aminotransferase activities, indicators of liver cell damage, were also elevated (up to 198%) at 48 and 72 h post-MA treatment. Fenofibrate blocks MA-induced hyperlipidemia, lipid accumulation in the liver, as well as liver injury. Oral administration of a mixture of schisandrin B, cholesterol, and bile salt could generate an interesting mouse model of combined hyperlipidemia associated with hepatic steatosis and steatohepatitis. PMID:24096833

  2. Nonlinear neural-network-based mixture model for estimating the concentration of nitrogen salts in turbid inland waters using hyperspectral imagery

    NASA Astrophysics Data System (ADS)

    Plaza, Javier; Martinez, Pablo J.; Perez, Rosa M.; Plaza, Antonio; Cantero, Carmen

    2004-12-01

    The development of hyperspectral imaging instruments designed for water quality assessment, such as the DLR Reflective Optics System Imaging Spectrometer (ROSIS), has created a need for methods which are able to infer water quality parameters of turbid inland waters, and to use those parameters as indicators for water quality. It has been reported that the irradiance reflectance and, subsequently, the radiance collected by the sensor in such scenario is usually the result of an intimate mixture of sub-pixel components. As a result, the commonly used linear mixing model may not be appropriate to describe materials composition. In this work, we develop a nonlinear neural network-based algorithm for estimating water constituent concentrations, with special emphasis on the detection of chemical substances provided by agricultural and industrial sources. The proposed neural network architecture consists of a modified multi-layer perceptron (MLP) whose entries are determined by a linear function activation provided by a Hopfield neural network algorithm (HNN). The combined HNN/MLP supervised model has been used to estimate the concentration of water constituents by training the MLP with ground spectra of nitrogen salts, which are commonly used in extensive agricultural farms. Such spectra were collected using a Minolta spectro-photometer. The model was calibrated in our laboratory by using mixtures of water and nitrogen salt in different proportions. Hyperspectral images collected by the ROSIS imaging spectrometer over the Guadiloba reservoir in Cáceres, SW Spain, are also used in this study to estimate the concentration of nitrogen salts in turbid inland waters.

  3. Directionally solidified eutectic ceramic oxides

    Microsoft Academic Search

    Javier LLorca; Victor M. Orera

    2006-01-01

    The processing, structure and properties (mechanical and functional) of directionally solidified eutectic ceramic oxides are reviewed with particular attention to the developments in the last 15 years. The article analyzes in detail the control of the microstructure from the processing variables, the recently gained knowledge on their microstructure (crystallographic orientation, interface structure, residual stresses, etc.), the microstructural and chemical stability

  4. Nonlinear Neural Network-Based Mixture Model for Estimating the Concentration of Nitrogen Salts in Turbid Inland Waters Using

    E-print Network

    Plaza, Antonio J.

    which are commonly used for industrial purposes; mineral contaminants such as heavy metals, phosphorus of water constituents by training the MLP with ground spectra of nitrogen salts, which are commonly used range of applications2-3 . Chemical and Biological Standoff Detection II, edited by James O. Jensen

  5. Corrosion of selected alloys in eutectic lithium-sodium-potassium carbonate at 900C

    Microsoft Academic Search

    R. T. Coyle; T. M. Thomas; P. Schissel

    1986-01-01

    There is an ongoing interest at the US Department of Energy in using molten salts as high temperature sensible heat storage media in advanced solar thermal systems. In this report, the compatibility of selected alloys in eutectic lithium-sodium-potassium carbonate, the salt that will be used in the near-term engineering experiments, has been evaluated at 900C. Several combinations of oxidation potential

  6. Mixture or Solution?

    NSDL National Science Digital Library

    steve burns

    2011-10-09

    Textbook definition: "Mixtures are formed simply by blending two or more substances together in some random proportion without chemically changing the individual substances in the mixture." Mixtures can then be broken down into homogeneous and heterogeneous. A homogeneous mixture is called a solution: salt or sugar and water, air (solution of gases). These have a constant composition throughout the solution. A heterogeneous mixture would be: salt with sugar (no water), water with gasoline or oil, salt with sand. These have areas with differing compositions (you could usually see the separation of the two things).

  7. Influence of salt and polymer on the critical vesicle concentration in aqueous mixture of zwitterionic\\/anionic surfactants

    Microsoft Academic Search

    Limin Zhai; Xiaojun Tan; Tao Li; Yanjing Chen; Xirong Huang

    2006-01-01

    Vesicles can be formed spontaneously in aqueous solution of surfactant mixture of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and lauryl sulfonate betaine (LSB). Different from the catanionic vesicles, the formation is dependent on surfactant concentration, mixing ratio and salinity due to the weak attraction between the two kinds of surfactant molecules, which provides possibility to determine the critical vesicle concentration (CVC), just

  8. Phase behavior of quinary mixtures of the type H/sub 2/O-oil-nonionic amphiphile-ionic amphiphile-salt

    SciTech Connect

    Kahlweit, M.; Strey, R.

    1988-03-24

    Five-component mixtures H/sub 2/O-oil-nonionic amphiphile-ionic amphiphile-salt may separate into three liquid phases. In this three-phase body one finds the highest mutual solubility between H/sub 2/O and oil, combined with the lowest interfacial tension between the aqueous and the oil-rich phase. The position of the three-phase body on the temperature scale as well as its extensions depends systematically on the nature of the components, on the ratio between the nonionic and ionic amphiphile, as well as on the brine concentration. An empirical description of the phase behavior is presented that permits qualitative predictions as to the temperature at which to find the three-phase body and what efficiency of the amphiphiles to expect.

  9. Io's surface composition based on reflectance spectra of sulfur/salt mixtures and proton-irradiation experiments

    NASA Technical Reports Server (NTRS)

    Nash, D. B.; Fanale, F. P.

    1977-01-01

    Available full-disk reflectance spectra of Io in the range 0.3 to 2.5 microns have been used to determine a surface compositional model for Io that is consistent with Io's other known chemical and physical properties. Results indicate that the surface of Io contains abundant dehydrated salts of high Na, Mg, and Fe(3+) content such as bloedite and ferrous iron sulfate. Experiments were performed studying the irradiation damage effects from low-energy proton bombardment, since Io is immersed in Jupiter's magnetosphere.

  10. COMPUTATIONAL THERMODYNAMIC MODELING OF HOT CORROSION OF ALLLOYS HAYNES 242 AND HASTELLOYTMN FOR MOLTEN SALT SERVICE

    SciTech Connect

    Michael V. Glazoff; Piyush Sabharwall; Akira Tokuhiro

    2014-09-01

    An evaluation of thermodynamic aspects of hot corrosion of the superalloys Haynes 242 and HastelloyTM N in the eutectic mixtures of KF and ZrF4 is carried out for development of Advanced High Temperature Reactor (AHTR). This work models the behavior of several superalloys, potential candidates for the AHTR, using computational thermodynamics tool (ThermoCalc), leading to the development of thermodynamic description of the molten salt eutectic mixtures, and on that basis, mechanistic prediction of hot corrosion. The results from these studies indicated that the principal mechanism of hot corrosion was associated with chromium leaching for all of the superalloys described above. However, HastelloyTM N displayed the best hot corrosion performance. This was not surprising given it was developed originally to withstand the harsh conditions of molten salt environment. However, the results obtained in this study provided confidence in the employed methods of computational thermodynamics and could be further used for future alloy design efforts. Finally, several potential solutions to mitigate hot corrosion were proposed for further exploration, including coating development and controlled scaling of intermediate compounds in the KF-ZrF4 system.

  11. Corrosion behavior of AISI 316L stainless steel and ODS FeAl aluminide in eutectic Li{sub 2}CO{sub 3}-K{sub 2}CO{sub 3} molten carbonates under flowing CO{sub 2}-O{sub 2} gas mixtures[Oxide Dispersion Strengthened

    SciTech Connect

    Frangini, S.

    2000-02-01

    A kinetics study on AISI 316L stainless steel and ODS (Oxide-Dispersion-Strengthened) FeAl iron aluminide was conducted concerning its corrosion behavior in molten Li{sub 2}CO{sub 3}-K{sub 2}CO{sub 3} eutectic at 650 C in flowing CO{sub 2}-O{sub 2} gas mixtures. The corrosion resistance of FeAl ODS was demonstrated to be significantly superior to that of austenitic AISI 316L steel under all gas conditions tested in this work. At low CO{sub 2} partial pressure (P{sub CO{sub 2}} = 0.3 atm) the corrosion rate of both alloys decreased with time due to the formation of a protective oxide layer. In dry CO{sub 2} gas, corrosion of AISI steel proceeded at a near-linear rate, indicative of a surface-controlled reaction. FeAl corroded initially following parabolic behavior, but, on further reaction, exhibited some weight loss. A similar behavior was also observed in a 67CO{sub 2}-33O{sub 2} gas mixture. Corrosion of FeAl in high CO{sub 2} gas has been postulated to initiate by acidic fluxing of yttria particles. The attack then develops as pitting and leads to further reaction by general corrosion as a consequence of the formation of active-passive electrochemical cells between the interior of pits and the external surface. The weight loss of AISI 316L in 67CO{sub 2}-33O{sub 2} gas can be ascribed to the high oxidizing power of the gas causing a continuous dissolution of the Cr{sub 2}O{sub 3}layer into a soluble chromate.

  12. Salt-induced vesicle formation from single anionic surfactant SDBS and its mixture with LSB in aqueous solution.

    PubMed

    Zhai, Limin; Zhao, Mei; Sun, Dejun; Hao, Jingcheng; Zhang, Lungjun

    2005-03-31

    Vesicles can be formed spontaneously in aqueous solution of a single anionic surfactant sodium dodecyl benzenesulfonate (SDBS) just under the inducement of salt, which makes the formation of vesicle much easier and simpler. The existence of vesicles was demonstrated by TEM image using the negative-staining method. The mechanism of the formation may be attributed to the compression of salt on the electric bilayer of the surfactant headgroups, which alters the packing parameter of the surfactant. The addition of the zwitterionic surfactant lauryl sulfonate betaine (LSB) makes the vesicles more stable, expands the range of formation and vesicle size, and reduces the polydispersity of the vesicles. The vesicle region was presented in a pseudoternary diagram of SDBS/LSB/brine. The variations of vesicle size with the salinity and mixing ratios, as well as the surfactant concentration, were determined using the dynamic light scattering method. It is found that the vesicle size is independent of the surfactant concentration but subject to the salinity and the mixing ratio of the two surfactants. PMID:16851606

  13. Asymmetric Binary Mixtures Under Cylindrical Confinement: A Molecular Dynamics Simulation Study

    E-print Network

    Biswas, Ranjit

    liquids, binary mixtures of ionic liquids with polar solvents, deep eutectics and model asymmetric and complex systems, such as, ionic liquids, deep eutectics, binary and ternary mixtures, poly simulation study on solute and solvent dynamics in neutral and charged reverse micelles have been carried out

  14. Liquid-liquid equilibria for the ternary system (phosphonium based deep eutectic solvent-benzene-hexane) at different temperatures: A new solvent introduced

    Microsoft Academic Search

    Mukhtar A. Kareem; Farouq S. Mjalli; M. A. Hashim; Inas M. AlNashef

    2012-01-01

    In this work we studied the applicability of one ionic liquid analogues namely phosphonium based deep eutectic solvent (DES) in the extraction of aromatic hydrocarbons from aromatic\\/aliphatic mixtures. Experimental data for liquid-liquid equilibria (LLE) were obtained for various mixtures of (benzene. +. hexane. +. DES) at 27, 35 and 45 °C. Some of the mixtures showed excellent results in terms

  15. Enhanced electroanalysis in lithium potassium eutectic (LKE) using microfabricated square microelectrodes.

    PubMed

    Corrigan, Damion K; Blair, Ewen O; Terry, Jonathan G; Walton, Anthony J; Mount, Andrew R

    2014-11-18

    Molten salts (MSs) are an attractive medium for chemical and electrochemical processing and as a result there is demand for MS-compatible analysis technologies. However, MSs containing redox species present a challenging environment in which to perform analytical measurements because of their corrosive nature, significant thermal convection and the high temperatures involved. This paper outlines the fabrication and characterization of microfabricated square microelectrodes (MSMs) designed for electrochemical analysis in MS systems. Their design enables precise control over electrode dimension, the minimization of stress because of differential thermal expansion through design for high temperature operation, and the minimization of corrosive attack through effective insulation. The exemplar MS system used for characterization was lithium chloride/potassium chloride eutectic (LKE), which has potential applications in pyrochemical nuclear fuel reprocessing, metal refining, molten salt batteries and electric power cells. The observed responses for a range of redox ions between 400 and 500 °C (673 and 773 K) were quantitative and typical of microelectrodes. MSMs also showed the reduced iR drop, steady-state diffusion-limited response, and reduced sensitivity to convection seen for microelectrodes under ambient conditions and expected for these electrodes in comparison to macroelectrodes. Diffusion coefficients were obtained in close agreement with literature values, more readily and at greater precision and accuracy than both macroelectrode and previous microelectrode measurements. The feasibility of extracting individual physical parameters from mixtures of redox species (as required in reprocessing) and of the prolonged measurement required for online monitoring was also demonstrated. Together, this demonstrates that MSMs provide enhanced electrode devices widely applicable to the characterization of redox species in a range of MS systems. PMID:25284431

  16. Aggregation behavior of sodium lauryl ether sulfate with a positively bicharged organic salt and effects of the mixture on fluorescent properties of conjugated polyelectrolytes.

    PubMed

    Tang, Yongqiang; Liu, Zhang; Zhu, Linyi; Han, Yuchun; Wang, Yilin

    2015-02-24

    The aggregation behavior of anionic single-chain surfactant sodium lauryl ether sulfate containing three ether groups (SLE3S) with positively bicharged organic salt 1,2-bis(2-benzylammoniumethoxy)ethane dichloride (BEO) has been investigated in aqueous solution, and the effects of the BEO/SLE3S aggregate transitions on the fluorescent properties of anionic conjugated polyelectrolyte MPS-PPV with a larger molecular weight and cationic conjugated oligoelectrolyte DAB have been evaluated. Without BEO, SLE3S does not affect the fluorescent properties of MPS-PPV and only affects the fluorescent properties of DAB at a higher SLE3S concentration. With the addition of BEO, SLE3S and BEO form gemini-like surfactant (SLE3S)2-BEO. When the BEO/SLE3S molar ratio is fixed at 0.25, with increasing the BEO/SLE3S concentration, the BEO/SLE3S mixture forms large, loosely arranged aggregates and then transforms to closely packed spherical aggregates and finally to long thread-like micelles. The photoluminescence (PL) intensity of MPS-PPV varies with the morphologies of the BEO/SLE3S aggregates, while the PL intensity of DAB is almost independent of the aggregate morphologies. The results demonstrate that gemini-like surfactants formed through intermolecular interactions can effectively adjust the fluorescent properties of conjugated polyelectrolytes. PMID:25641198

  17. High thermoelectric figure of merit and improved mechanical properties in melt quenched PbTe-Ge and PbTe-Ge1-xSix eutectic and hypereutectic composites

    Microsoft Academic Search

    Joseph R. Sootsman; Jiaqing He; Vinayak P. Dravid; Chang-Peng Li; Ctirad Uher; Mercouri G. Kanatzidis

    2009-01-01

    We report the synthesis, microstructure, and transport properties of composite thermoelectric materials based on the eutectic phase relationship between PbTe and Ge. When quenched, these eutectic mixtures exhibit considerably stronger mechanical strength and reduced brittleness compared to PbTe itself, while at the same time they possess lower lattice thermal conductivity. Thermal conductivity measurements show values lower than expected based on

  18. High thermoelectric figure of merit and improved mechanical properties in melt quenched PbTe-Ge and PbTe-Ge{sub 1-x}Siâ eutectic and hypereutectic composites

    Microsoft Academic Search

    J. R. Sootsman; J. He; V. P. Dravid; C. P. Li; C. Uher; M. G. Kanatzidis

    2009-01-01

    We report the synthesis, microstructure, and transport properties of composite thermoelectric materials based on the eutectic phase relationship between PbTe and Ge. When quenched, these eutectic mixtures exhibit considerably stronger mechanical strength and reduced brittleness compared to PbTe itself, while at the same time they possess lower lattice thermal conductivity. Thermal conductivity measurements show values lower than expected based on

  19. Hygroscopic properties of NaCl and NaNO3 mixture particles as reacted inorganic sea-salt aerosol surrogates

    NASA Astrophysics Data System (ADS)

    Gupta, D.; Kim, H.; Park, G.; Li, X.; Eom, H.-J.; Ro, C.-U.

    2014-12-01

    NaCl in fresh sea-salt aerosol (SSA) particles can partially or fully react with atmospheric NOx / HNO3, so internally mixed NaCl and NaNO3 aerosol particles can co-exist over a wide range of mixing ratios. Laboratory-generated, micrometer-sized NaCl and NaNO3 mixture particles at ten mixing ratios (mole fractions of NaCl (XNaCl) = 0.1 to 0.9) were examined systematically to observe their hygroscopic behavior, derive experimental phase diagrams for deliquescence and efflorescence, and understand the efflorescence mechanism. During the humidifying process, aerosol particles with the eutonic composition (XNaCl = 0.38) showed only one phase transition at their mutual deliquescence relative humidity (MDRH) of 67.9(± 0.5)%. On the other hand, particles with other mixing ratios showed two distinct deliquescence transitions, i.e., the eutonic component dissolved at MDRH and the remainder in the solid phase dissolved completely at their DRHs depending on the mixing ratios, resulting in a phase diagram composed of four different phases, as predicted thermodynamically. During the dehydration process, NaCl-rich particles (XNaCl > 0.38) showed two-stage efflorescence transitions: the first stage was purely driven by the homogeneous nucleation of NaCl and the second stage at the mutual efflorescence RH (MERH) of the eutonic components, with values in the range of 30.0-35.5%. Interestingly, aerosol particles with the eutonic composition (XNaCl = 0.38) also showed two-stage efflorescence with NaCl crystallizing first followed by heterogeneous nucleation of the remaining NaNO3 on the NaCl seeds. NaNO3-rich particles XNaCl ? 0.3) underwent single-stage efflorescence transitions at ERHs progressively lower than the MERH, because of the homogeneous nucleation of NaCl and the almost simultaneous heterogeneous nucleation of NaNO3 on the NaCl seeds. SEM/EDX elemental mapping indicated that the effloresced NaCl-NaNO3 particles at all mixing ratios were composed of a homogeneously crystallized NaCl moiety in the center, surrounded either by the eutonic component (for XNaCl > 0.38) or NaNO3 (for XNaCl ? 0.38). During the humidifying or dehydration process, the amount of eutonic composed part drives particle/droplet growth or shrinkage at the MDRH or MERH (second ERH), respectively, and the amount of remnant pure salts (NaCl or NaNO3 in NaCl- or NaNO3-rich particles, respectively) drives the second DRHs or first ERHs, respectively. Therefore, their behavior can be a precursor to the optical properties and direct radiative forcing for these atmospherically relevant mixture particles representing the coarse, reacted inorganic SSAs. In addition, the NaCl-NaNO3 mixture aerosol particles can maintain an aqueous phase over a wider RH range than the genuine SSA surrogate (i.e., pure NaCl particles), making their heterogeneous chemistry more probable.

  20. Hygroscopic properties of NaCl and NaNO3 mixture particles as reacted inorganic sea-salt aerosol surrogates

    NASA Astrophysics Data System (ADS)

    Gupta, D.; Kim, H.; Park, G.; Li, X.; Eom, H.-J.; Ro, C.-U.

    2015-03-01

    NaCl in fresh sea-salt aerosol (SSA) particles can partially or fully react with atmospheric NOx/HNO3, so internally mixed NaCl and NaNO3 aerosol particles can co-exist over a wide range of mixing ratios. Laboratory-generated, micrometer-sized NaCl and NaNO3 mixture particles at 10 mixing ratios (mole fractions of NaCl (XNaCl) = 0.1 to 0.9) were examined systematically to observe their hygroscopic behavior, derive experimental phase diagrams for deliquescence and efflorescence, and understand the efflorescence mechanism. During the humidifying process, aerosol particles with the eutonic composition (XNaCl = 0.38) showed only one phase transition at their mutual deliquescence relative humidity (MDRH) of 67.9 (±0.5)% On the other hand, particles with other mixing ratios showed two distinct deliquescence transitions; i.e., the eutonic component dissolved at MDRH, and the remainder in the solid phase dissolved completely at their DRHs depending on the mixing ratios, resulting in a phase diagram composed of four different phases, as predicted thermodynamically. During the dehydration process, NaCl-rich particles (XNaCl > 0.38) showed a two stage efflorescence transition: the first stage was purely driven by the homogeneous nucleation of NaCl and the second stage at the mutual efflorescence RH (MERH) of the eutonic components, with values in the range of 30.0-35.5%. Interestingly, aerosol particles with the eutonic composition (XNaCl = 0.38) also showed two-stage efflorescence, with NaCl crystallizing first followed by heterogeneous nucleation of the remaining NaNO3 on the NaCl seeds. NaNO3-rich particles (XNaCl ? 0.3) underwent single-stage efflorescence transitions at ERHs progressively lower than the MERH because of the homogeneous nucleation of NaCl and the almost simultaneous heterogeneous nucleation of NaNO3 on the NaCl seeds. SEM/EDX elemental mapping indicated that the effloresced NaCl-NaNO3 particles at all mixing ratios were composed of a homogeneously crystallized NaCl moiety in the center, surrounded either by the eutonic component (for XNaCl > 0.38) or NaNO3 (for XNaCl ? 0.38). During the humidifying or dehydration process, the amount of eutonic composed part drives particle/droplet growth or shrinkage at the MDRH or MERH (second ERH), respectively, and the amount of pure salts (NaCl or NaNO3 in NaCl- or NaNO3-rich particles, respectively) drives the second DRHs or first ERHs, respectively. Therefore, their behavior can be a precursor to the optical properties and direct radiative forcing for these atmospherically relevant mixture particles representing the coarse, reacted inorganic SSAs. In addition, the NaCl-NaNO3 mixture aerosol particles can maintain an aqueous phase over a wider RH range than pure NaCl particles as SSA surrogate, making their heterogeneous chemistry more probable.

  1. Thermal storage in ammonium alum/ammonium nitrate eutectic for solar space heating

    SciTech Connect

    Goswami, D.Y.; Jotshi, C.K.; Klausner, J.F.; Hsieh, C.K.; Srinivasan, N. [Univ. of Florida, Gainesville, FL (United States). Dept. of Mechanical Engineering

    1995-10-01

    Ammonium alum and ammonium nitrate in the weight ratio of 1:1 forms a eutectic that melts at 53 C and crystallizes at 48 C. The latent heat of fusion of this eutectic was found to be 215 kJ/kg. Its enthalpy as measured by drop calorimetry was found to be 287 kJ/kg in the temperature range of 24--65 C, which is 1.67 times greater than water (172.2 kJ/kg) and 8.75 times greater than rock (32.8 kJ/kg). Upon several heating/cooling cycles, phase separation was observed. However, by adding 5% attapulgite clay to this eutectic mixture, phase separation was prevented. This eutectic was encapsulated in 0.0254m diameter HDPE hollow balls and subjected to about 1,100 heating/cooling cycles in the temperature range between 25 and 65 C. At the end of these cycles, the decrease in enthalpy was found to be 5%. A scale model of the heat storage unit was fabricated to investigate the heat transfer characteristics of this eutectic encapsulated in HDPE balls. The thermal extraction efficiency of the system was measured with the recirculation of hot air during charging and was found to be in the range of 85--98%.

  2. Physicochemical properties of ammonium-based deep eutectic solvents and their electrochemical evaluation using organometallic reference redox systems

    Microsoft Academic Search

    L. Bahadori; M. H. Chakrabarti; F. S. Mjalli; I. M. Alnashef; N. S. A. Manan; M. A. Hashim

    2013-01-01

    Seven deep eutectic solvents (DESs) containing ammonium based salts are prepared by means of hydrogen bonding with acid, amine, amide and nitrate based compounds. The major physicochemical properties of the DESs in terms of density, viscosity, electrical conductivity, molar conductivity and pH are investigated prior to ascertaining their electrochemical characteristics by means of cyclic voltammetry and chronoamperometry. Nitrate based DESs

  3. Electrical conductivity of ammonium and phosphonium based deep eutectic solvents: Measurements and artificial intelligence-based prediction

    Microsoft Academic Search

    F. S. G. Bagh; K. Shahbaz; F. S. Mjalli; I. M. AlNashef; M. A. Hashim

    2013-01-01

    The evaluation of deep eutectic solvents (DESs) as a new generation of solvents for various practical application requires an insight of the main physical, chemical, and thermodynamic properties. In this study, the experimental measurements of the electrical conductivity of two classes of DESs based on ammonium and phosphonium salts at different compositions and temperatures were reported. The results revealed that

  4. Prospects of applying ionic liquids and deep eutectic solvents for renewable energy storage by means of redox flow batteries

    Microsoft Academic Search

    M. H. Chakrabarti; F. S. Mjalli; I. M. Alnashef; M. A. Hashim; M. A. Hussain; L. Bahadori; C. T. J. Low

    2014-01-01

    Ionic liquids (ILs) and deep eutectic solvents (DESs) have been applied in various fields such as electrolytes for lithium ion batteries, electrodeposition, electropolishing and even in fuel cells. ILs and molten salts have found some applications in redox flow batteries (RFBs) in the past and recently some metal ion based ILs have been proposed and used by Sandia National Laboratories.

  5. Aligned CoCo 2 Si eutectics

    Microsoft Academic Search

    J. D. Livingston

    1976-01-01

    The addition of W, Ta, or Al to Co-rich Co-Si alloys suppresses the formation of Co3Si and produces stable eutectics between the Co2Si and the Co-rich solid-solution phase. The Co-Si-W and Co-Si-Ta alloys solidified as three-phase eutectics. The Co-Si-Al alloy solidified as a two-phase eutectic, but a third phase precipitated on cooling. Interesting morphological changes were produced by epitaxial precipitation

  6. Electrode reaction of plutonium at liquid cadmium in LiCl–KCl eutectic melts

    Microsoft Academic Search

    O. Shirai; M. Iizuka; T. Iwai; Y. Suzuki; Y. Arai

    2000-01-01

    The electrode reaction of the Pu3+\\/Pu couple at the surface of a liquid Cd electrode was investigated by cyclic voltammetry at 723, 773 and 823 K in LiCl?KCl eutectic melt. It was found that the diffusion of Pu3+ in the salt phase was a rate-determining step in the cathodic reaction, but the dissolution of Pu from the liquid Cd phase

  7. Germanium nanowire growth below the eutectic temperature.

    PubMed

    Kodambaka, S; Tersoff, J; Reuter, M C; Ross, F M

    2007-05-01

    Nanowires are conventionally assumed to grow via the vapor-liquid-solid process, in which material from the vapor is incorporated into the growing nanowire via a liquid catalyst, commonly a low-melting point eutectic alloy. However, nanowires have been observed to grow below the eutectic temperature, and the state of the catalyst remains controversial. Using in situ microscopy, we showed that, for the classic Ge/Au system, nanowire growth can occur below the eutectic temperature with either liquid or solid catalysts at the same temperature. We found, unexpectedly, that the catalyst state depends on the growth pressure and thermal history. We suggest that these phenomena may be due to kinetic enrichment of the eutectic alloy composition and expect these results to be relevant for other nanowire systems. PMID:17478716

  8. Eutectic Contact Inks for Solar Cells

    NASA Technical Reports Server (NTRS)

    Ross, B.

    1985-01-01

    Low-resistance electrical contacts formed on solar cells by melting powders of eutectic composition of semiconductor and dopant. Process improves cell performance without subjecting cell to processing temperatures high enough to degrade other characteristics.

  9. The promise of eutectics for aircraft turbines

    NASA Technical Reports Server (NTRS)

    Gray, H. R.

    1977-01-01

    The current status of the first generation eutectics, gamma/gamma transition - delta and NiTaC-13, is described in detail. Several second generation systems, such as gamma/gamma transition - alpha and NiTaC 3-116A, gamma - beta, and COTAC 74 are also reviewed with particular emphasis on their critical physical and mechanical properties, future research directions, and potential applications. Results of recent cost-benefit analyses of eutectic turbine blades are discussed.

  10. Resolving Issues of Content Uniformity and Low Permeability Using Eutectic Blend of Camphor and Menthol

    PubMed Central

    Gohel, M. C.; Nagori, S. A.

    2009-01-01

    The aim of present study were to arrest the problem of content uniformity without the use of harmful organic solvent and to improve ex vivo permeability of captopril, a low dose class III drug as per biological classification system. Eutectic mixture of camphor and menthol was innovatively used in the work. Captopril solution in eutectic mixture was blended with Avicel PH 102 and then the mixture was blended with mannitol in different ratios. Formulated batches were characterized for angle of repose and Carr's index. A selected batch was filled in hard gelatin capsule. Tablet dosage form was also developed. Capsules and tablets were characterized for in vitro drug release in 0.1N HCl. Additionally, the captopril tablets were analyzed for content uniformity and ex vivo drug permeation study using rat ileum in modified apparatus. The measurement of angle of repose and Carr's index revealed that the powder blend exhibited good flow property and compressibility. The captopril capsules and tablets exhibited immediate drug release in 0.1 N HCl. The captopril tablets passed content uniformity test as per IP 1996. Ex vivo permeation of captopril, formulated with eutectic mixture, was faster than control. The permeation was increased by 15% at the end of 3 h. Tablets and capsule exhibited reasonable short term stability with no considerable change in performance characteristics. PMID:20376214

  11. Eutectic experiment development for space processing

    NASA Technical Reports Server (NTRS)

    Hopkins, R. H.

    1972-01-01

    A ground base test plan and a specimen evaluation scheme have been developed for the aluminum-copper eutectic solidification experiment to be run in the M518 multipurpose electric furnace during the Skylab mission. Besides thermal and solidification studies a detailed description is given of the quantitative metallographic technique which is appropriate for characterizing eutectic structures. This method should prove a key tool for evaluating specimen microstructure which is the most sensitive indicator of changes produced during solidification. It has been recommended that single grain pre-frozen eutectic specimens be used to simplify microstructural evaluation and to eliminate any porosity in the as-cast eutectic specimens. High purity (99.999%) materials from one supplier should be employed for all experiments. Laboratory studies indicate that porosity occurs in the MRC as-cast eutectic ingots but that this porosity can be eliminated by directional freezing. Chemical analysis shows that the MRC ingots are slightly Al rich and contain about .03% impurity. Because of the impurity content the lower cooldown rate (1.2 C/min) should be used for eutectic freezing if MRC material is used in the M518 furnace.

  12. The ionothermal synthesis of metal organic frameworks, Ln(C 9O 6H 3)((CH 3NH) 2CO) 2, using deep eutectic solvents

    Microsoft Academic Search

    Farida Himeur; Irene Stein; David S. Wragg; Alexandra M. Z. Slawin; Philip Lightfoot; Russell E. Morris

    2010-01-01

    Three new isostructural materials Ln(TMA)(DMU)2 (Ln(C9O6H3)((CH3NH)2CO)2; Ln: La 1, Nd 2, Eu 3; TMA: trimesate, DMU: dimethylurea) have been synthesised ionothermally using a choline chloride\\/dimethylurea deep eutectic mixture as the solvent. Normally in ionothermal synthesis the urea portion of the deep eutectic solvent is unstable, breaking down to release ammonium cations that act as templates. In the case of 1–3,

  13. Modeling Solute Thermokinetics in LiCI-KCI Molten Salt for Nuclear Waste Separation

    SciTech Connect

    Morgan, Dane; Eapen, Jacob

    2013-10-01

    Recovery of actinides is an integral part of a closed nuclear fuel cycle. Pyrometallurgical nuclear fuel recycling processes have been developed in the past for recovering actinides from spent metallic and nitride fuels. The process is essentially to dissolve the spent fuel in a molten salt and then extract just the actinides for reuse in a reactor. Extraction is typically done through electrorefining, which involves electrochemical reduction of the dissolved actinides and plating onto a cathode. Knowledge of a number of basic thermokinetic properties of salts and salt-fuel mixtures is necessary for optimizing present and developing new approaches for pyrometallurgical waste processing. The properties of salt-fuel mixtures are presently being studied, but there are so many solutes and varying concentrations that direct experimental investigation is prohibitively time consuming and expensive (particularly for radioactive elements like Pu). Therefore, there is a need to reduce the number of required experiments through modeling of salt and salt-fuel mixture properties. This project will develop first-principles-based molecular modeling and simulation approaches to predict fundamental thermokinetic properties of dissolved actinides and fission products in molten salts. The focus of the proposed work is on property changes with higher concentrations (up to 5 mol%) of dissolved fuel components, where there is still very limited experimental data. The properties predicted with the modeling will be density, which is used to assess the amount of dissolved material in the salt; diffusion coefficients, which can control rates of material transport during separation; and solute activity, which determines total solubility and reduction potentials used during electrorefining. The work will focus on La, Sr, and U, which are chosen to include the important distinct categories of lanthanides, alkali earths, and actinides, respectively. Studies will be performed using LiCl-KCl salt at the eutectic composition (58 mol% LiCl, 42 mol% KCl), which is used for treating spent EBR-II fuel. The same process being used for EBRII fuel is currently being studied for widespread international implementation. The methods will focus on first-principles and first- principles derived interatomic potential based simulations, primarily using molecular dynamics. Results will be validated against existing literature and parallel ongoing experimental efforts. The simulation results will be of value for interpreting experimental results, validating analytical models, and for optimizing waste separation by potentially developing new salt configurations and operating conditions.

  14. Separating a Mixture

    NSDL National Science Digital Library

    2012-07-12

    This activity was designed for blind learners, but all types of learners can explore means of physically separating a mixture using dissolving, filtration, and evaporation. Separating a sand/salt mixture is a common experiment in physical science class that requires almost no adaptation for learners with visual impairments. This activity also provides experience in popular laboratory techniques of dissolving, filtration, and evaporation. In this activity, the learner will use filters and funnels to separate sand and salt.

  15. Thermodynamic study of (anthracene + benzo[a]pyrene) solid mixtures

    PubMed Central

    Rice, James W.; Suuberg, Eric M.

    2010-01-01

    To characterize better the thermodynamic behavior of a binary polycyclic aromatic hydrocarbon mixture, thermochemical and vapor pressure experiments were used to examine the phase behavior of the {anthracene (1) + benzo[a]pyrene (2)} system. A solid-liquid phase diagram was mapped for the mixture. A eutectic point occurs at x1 = 0.26. The eutectic mixture is an amorphous solid that lacks organized crystal structure and melts between T = (414 and 420) K. For mixtures that contain 0.10 < x1 < 0.90, the enthalpy of fusion is dominated by that of the eutectic. Solid-vapor equilibrium studies show that mixtures of anthracene and benzo[a]pyrene at x1 < 0.10 sublime at the vapor pressure of pure benzo[a]pyrene. These results suggest that the solid-vapor equilibrium of benzo[a]pyrene is not significantly influenced by moderate levels of anthracene in the crystal structure. PMID:20814451

  16. Deep eutectic solvents (DESs) are viable cosolvents for enzyme-catalyzed epoxide hydrolysis

    Microsoft Academic Search

    Diana Lindberg; Mario de la Fuente Revenga; Mikael Widersten

    2010-01-01

    A special group of ionic liquids, deep eutectic solvents (DESs) have been tested as cosolvents in enzyme-catalyzed hydrolysis of a chiral (1,2)-trans-2-methylstyrene oxide. The choline chloride:ethane diol (ET), choline chloride:glycerol (GLY) and choline:chloride:urea (REL) DESs were included in the reaction mixtures with epoxide and the potato epoxide hydrolase StEH1. The effect of the DESs on enzyme function was primarily elevations

  17. Electrodeposition of Co, Sm and SmCo from a Deep Eutectic Solvent

    Microsoft Academic Search

    E. Gómez; P. Cojocaru; L. Magagnin; E. Valles

    2011-01-01

    The suitability of 1 choline chloride:2 urea mixture, Deep Eutectic Solvent (DES) for the electrodeposition of cobalt, samarium and cobalt–samarium system has been studied. Its electrochemical window permits deposition analysis to be carried out without interference from parallel reactions. Deposition was studied at 70°C in order to stimulate mass transfer and to lower solution viscosity.Cobalt deposits according to a nucleation

  18. Influence of freezing rate changes on MnBi-Bi eutectic microstructure

    Microsoft Academic Search

    William R. Wilcox; Krishna Doddi; Manju Nair; David J. Larson

    1983-01-01

    In an attempt to explain the influence of space processing on the microstructure of MnBi-Bi, eutectic mixtures were directionally solidified with a sudden change of translation rate. The MnBi fiber spacing was able to adapt to the changing freezing rate as predicted by heat transfer computations. Thus the microstructure adapts more rapidly than the freezing rate could be changed in

  19. Influence of freezing rate changes of MnBi-Bi eutectic microstructure. [effects of space processing

    NASA Technical Reports Server (NTRS)

    Wilcox, W. R.; Doddi, K.; Nair, M.; Larson, D. J.

    1983-01-01

    In an attempt to explain the influence of space processing on the microstructure of MnBi-Bi, eutectic mixtures were directionally solidified with a sudden change of translation rate. The MnBi fiber spacing was able to adapt to the changing freezing rate as predicted by heat transfer computations. Thus the microstructure adapts more rapidly than the freezing rate could be changed in the present experiments.

  20. Glass transition and mixing thermodynamics of a binary eutectic system.

    PubMed

    Tu, Wenkang; Chen, Zeming; Gao, Yanqin; Li, Zijing; Zhang, Yaqi; Liu, Riping; Tian, Yongjun; Wang, Li-Min

    2014-02-28

    A quantitative evaluation of the contribution of mixing thermodynamics to glass transition is performed for a binary eutectic benzil and m-nitroaniline system. The microcalorimetric measurements of the enthalpy of mixing give small and positive values, typically ~200 J mol(-1) for the equimolar mixture. The composition dependence of the glass transition temperature, T(g), is found to show a large and negative deviation from the ideal mixing rule. The Gordon-Taylor and Couchman-Karasz models are subsequently applied to interpret the T(g) behavior, however, only a small fraction of the deviation is explained. The analyses of the experimental results manifest quantitatively the importance of the mixing thermodynamics in the glass transition in miscible systems. PMID:24413254

  1. Directionally solidified eutectic alloy gamma-beta

    NASA Technical Reports Server (NTRS)

    Tewari, S. N.

    1977-01-01

    A pseudobinary eutectic alloy composition was determined by a previously developed bleed-out technique. The directionally solidified eutectic alloy with a composition of Ni-37.4Fe-10.0Cr-9.6Al (in wt%) had tensile strengths decreasing from 1,090 MPa at room temperature to 54 MPa at 1,100 C. The low density, excellent microstructural stability, and oxidation resistance of the alloy during thermal cycling suggest that it might have applicability as a gas turbine vane alloy while its relatively low high temperature strength precludes its use as a blade alloy. A zirconium addition increased the 750 C strength, and a tungsten addition was ineffective. The gamma=beta eutectic alloys appeared to obey a normal freezing relation.

  2. Some physicochemical studies on organic eutectics

    NASA Astrophysics Data System (ADS)

    Gupta, R. K.; Singh, S. K.; Singh, R. A.

    2007-03-01

    The phase diagrams of phenothiazine with each of m-nitrobenzoic acid ( m-NBA) and m-dinitrobenzene ( m-DNB) have been studied by thaw-melt method. These materials have been characterized by X-ray diffraction. Growth behavior of the parent components, eutectic and charge transfer complex (CTC) studied by measuring the rate of movement of the growth front in a capillary suggests the applicability of Hillig-Turnbull equation for the system. Microstructure and electrical conductivities of congruent melting complexes and eutectics have been determined. The low electrical conductivities of these materials have been due to weak interaction and mixed stacking of donor and acceptor. Excess thermodynamics functions of the charge-transfer (CT) materials and eutectics have been determined.

  3. Eutectic growth under acoustic levitation conditions.

    PubMed

    Xie, W J; Cao, C D; Lü, Y J; Wei, B

    2002-12-01

    Samples of Pb-Sn eutectic alloy with a high density of 8.5 x 10(3) kg/m(3) are levitated with a single-axis acoustic levitator, and containerlessly melted and then solidified in argon atmosphere. High undercoolings up to 38 K are obtained, which results in a microstructural transition of "lamellas-broken lamellas-dendrites." This transition is further investigated in the light of the coupled zone for eutectic growth and the effects of ultrasound. The breaking of regular eutectic lamellas and suppression of gravity-induced macrosegregation of (Pb) and (Sn) dendrites are explained by the complicated internal flow inside the levitated drop, which is jointly induced by the shape oscillation, bulk vibration and rotation of the levitated drop. The ultrasonic field is also found to drive forced surface vibration, which subsequently excites capillary ripples and catalyzes nucleation on the sample surface. PMID:12513291

  4. Lamellar eutectic growth with anisotropic interphase boundaries

    NASA Astrophysics Data System (ADS)

    Akamatsu, S.; Bottin-Rousseau, S.; Faivre, G.; Ghosh, S.; Plapp, M.

    2015-06-01

    We present a numerical study of the effect of a free-energy anisotropy of the solid- solid interphase boundaries on the formation of tilted lamellar microstructures during directional solidification of nonfaceted binary eutectic alloys. We used two different methods - phase-field (PF) and dynamic boundary-integral (BI) - to simulate the growth of periodic eutectic patterns in two dimensions. For a given Wulff plot of the interphase boundary, which characterizes a eutectic grain with a given relative orientation of the two solid phases, the lamellar tilt angle depends on the angle between the thermal axis z and a reference crystallographic axis. Both PF and BI results confirm the general validity of a recent approximate theory which assumes that, at the trijunctions, the surface tension vector of the interphase boundary is parallel to z. In particular, a crystallographic locking of the lamellae onto a direction close to a deep minimum in the Wulff plot is well reproduced in the simulations.

  5. Tin-silver-copper eutectic temperature and composition

    Microsoft Academic Search

    M. E. Loomans; M. E. Fine

    2000-01-01

    A careful investigation of the Sn-Ag-Cu phase diagram near the ternary eutectic composition was undertaken using annealed\\u000a alloys and differential scanning calorimetry to settle some uncertainties in the eutectic composition. The eutectic composition\\u000a was found to be 3.5 wt pct Ag, 0.9 wt pct Cu, and the balance Sn. The published eutectic temperature, 217 C, was confirmed.\\u000a A value of

  6. A solar-thermal energy harvesting scheme: enhanced heat capacity of molten HITEC salt mixed with Sn/SiO(x) core-shell nanoparticles.

    PubMed

    Lai, Chih-Chung; Chang, Wen-Chih; Hu, Wen-Liang; Wang, Zhiming M; Lu, Ming-Chang; Chueh, Yu-Lun

    2014-05-01

    We demonstrated enhanced solar-thermal storage by releasing the latent heat of Sn/SiO(x) core-shell nanoparticles (NPs) embedded in a eutectic salt. The microstructures and chemical compositions of Sn/SiO(x) core-shell NPs were characterized. In situ heating XRD provides dynamic crystalline information about the Sn/SiO(x) core-shell NPs during cyclic heating processes. The latent heat of ?29 J g(-1) for Sn/SiO(x) core-shell NPs was measured, and 30% enhanced heat capacity was achieved from 1.57 to 2.03 J g(-1) K(-1) for the HITEC solar salt without and with, respectively, a mixture of 5% Sn/SiO(x) core-shell NPs. In addition, an endurance cycle test was performed to prove a stable operation in practical applications. The approach provides a method to enhance energy storage in solar-thermal power plants. PMID:24675904

  7. Contact melting and the structure of binary eutectic near the eutectic point

    E-print Network

    Oleksiy Bystrenko; Valeriy Kartuzov

    2014-09-04

    Computer simulations of contact melting and associated interfacial phenomena in binary eutectic systems were performed on the basis of the standard phase-field model with miscibility gap in solid state. It is shown that the model predicts the existence of equilibrium three-phase (solid-liquid-solid) states above the eutectic temperature, which suggest the explanation of the phenomenon of phase separation in liquid eutectic observed in experiments. The results of simulations provide the interpretation for the phenomena of contact melting and formation of diffusion zone observed in the experiments with binary metal-silicon systems.

  8. Microstructure Of MnBi/Bi Eutectic Alloy

    NASA Technical Reports Server (NTRS)

    Wilcox, William R.; Eisa, G. F.; Baskaran, B.; Richardson, Donald C.

    1988-01-01

    Collection of three reports describes studies of directional solidification of MnBi/Bi eutectic alloy. Two of the reports, "Influence of Convection on Lamellar Spacing of Eutectics" and "Influence of Convection on Eutectic Microstructure," establish theoretical foundation for remaining document. Reports seek to quantify effect of convection on concentration field of growing lamellar eutectic. Remaining report, "Study of Eutectic Formation," begins by continuing theoretical developments. New technique under development by one of the authors helps to reveal three-dimensional microstructures of alloys.

  9. Pb-free Sn-Ag-Cu ternary eutectic solder

    DOEpatents

    Anderson, I.E.; Yost, F.G.; Smith, J.F.; Miller, C.M.; Terpstra, R.L.

    1996-06-18

    A Pb-free solder includes a ternary eutectic composition consisting essentially of about 93.6 weight % Sn-about 4.7 weight % Ag-about 1.7 weight % Cu having a eutectic melting temperature of about 217 C and variants of the ternary composition wherein the relative concentrations of Sn, Ag, and Cu deviate from the ternary eutectic composition to provide a controlled melting temperature range (liquid-solid ``mushy`` zone) relative to the eutectic melting temperature (e.g. up to 15 C above the eutectic melting temperature). 5 figs.

  10. Eutectic spacing and faults of directionally solidified Al–Al 3Ni eutectic

    Microsoft Academic Search

    Y. X. Zhuang; X. M. Zhang; L. H. Zhu; Z. Q. Hu

    2001-01-01

    The Al–Al3Ni eutectic was directionally solidified at a thermal gradient of 4.5K\\/mm in a vacuum Bridgman-type furnace in order to study eutectic spacing selection criterion. The microstructure was examined in transverse and longitudinal sections and the interrod spacings were measured at different growth velocity. It has been shown that the interrod spacing is not unique and displays a limited range

  11. Are deep eutectic solvents benign or toxic?

    Microsoft Academic Search

    M. Hayyan; M. A. Hashim; A. Hayyan; M. A. Al-Saadi; I. M. AlNashef; M. E. S. Mirghani; O. K. Saheed

    2013-01-01

    In continuation of investigation for environmentally benign protocol for new solvents termed deep eutectic solvents (DESs), it is herein reported results concerning the toxicity and cytotoxicity of choline chloride (ChCl) based DESs with four hydrogen bond donors including glycerine, ethylene glycol, triethylene glycol and urea. The toxicity was investigated using two Gram positive bacteria Bacillus subtilis and Staphylococcus aureus, and

  12. Development of High-Temperature Transport Technologies of Molten Salt Slurry in Pyrometallurgical Reprocessing

    NASA Astrophysics Data System (ADS)

    Hijikata, Takatoshi; Koyama, Tadafumi

    Pyrometallurgical-reprocessing is one of the most promising technologies for advanced fuel cycle with favorable economic potential and intrinsic proliferation resistance. The development of transport technology for molten salt is a key issue in the industrialization of pyro-reprocessing. As for pure molten LiCl-KCl eutectic salt at approximately 773 K, we have already reported the successful results of transport using gravity and a centrifugal pump. However, molten salt in an electrorefiner mixes with insoluble fines when spent fuel is dissolved in porous anode basket. The insoluble consists of noble metal fission products, such as Pd, Ru, Mo, and Zr. There have been very few transport studies of a molten salt slurry (metal fines-molten salt mixture). Hence, transport experiments on a molten salt slurry were carried out to investigate the behavior of the slurry in a tube. The apparatus used in the transport experiments on the molten salt slurry consisted of a supply tank, a 10° inclined transport tube (10 mm inner diameter), a valve, a filter, and a recovery tank. Stainless steel (SS) fines with diameters from 53 to 415 ?m were used. To disperse these fines homogenously, the molten salt and fines were stirred in the supply tank by an impeller at speeds from 1200 to 2100 rpm. The molten salt slurry containing 0.04 to 0.4 vol.% SS fines was transported from the supply tank to the recovery tank through the transportation tube. In the recovery tank, the fines were separated from the molten salt by the filter to measure the transport behavior of molten salt and SS fines. When the velocity of the slurry was 0.02 m/s, only 1% of the fines were transported to the recovery tank. On the other hand, most of the fines were transported when the velocity of the slurry was more than 0.8 m/s. Consequently, the molten salt slurry can be transported when the velocity is more than 0.8 m/s.

  13. Evaluating the Performance of Deep Eutectic Solvents for Use in Extractive Denitrification of Liquid Fuels by the Conductor-like Screening Model for Real Solvents

    Microsoft Academic Search

    Hanee F. Hizaddin; Anantharaj Ramalingam; Mohd Ali Hashim; Mohamed K. O. Hadj-Kali

    2014-01-01

    A total of 94 deep eutectic solvents (DESs) based on different combinations of salt cation, anion, hydrogen-bond donor (HBD) and salt:HBD molar ratio are screened via the conductor-like screening model for real solvents for potential use in the extractive denitrification of diesel. Five nonbasic and six basic nitrogen compounds were included in this study. The activity coefficient at infinite dilution,

  14. A novel phosphonium-based deep eutectic catalyst for biodiesel production from industrial low grade crude palm oil

    Microsoft Academic Search

    Adeeb Hayyan; Mohd Ali Hashim; Farouq S. Mjalli; Maan Hayyan; Inas M. AlNashef

    2013-01-01

    This study explores the possibility of producing low grade crude palm oil (LGCPO)-based biodiesel using a two-stage process in which a phosphonium-based deep eutectic solvent (P-DES) and an alkali are used as catalysts. The pre-treatment of LGCPO was conducted using a P-DES composed of a hydrogen bond donor (i.e. p-toluenesulfonic acid monohydrate) and a salt (i.e. allyltriphenylphosphonium bromide) as a

  15. A novel ammonium based eutectic solvent for the treatment of free fatty acid and synthesis of biodiesel fuel

    Microsoft Academic Search

    A. Hayyan; M. A. Hashim; M. Hayyan; F. S. Mjalli; I. M. AlNashef

    2013-01-01

    In this work, low grade crude palm oil (LGCPO) with high free fatty acids (FFA) content is introduced as a possible biodiesel production feedstock alternative. The pre-treatment of LGCPO was conducted using ammonium-based deep eutectic solvent which consisted of hydrogen bond donor (i.e. p-toluenesulfonic acid monohydrate) (PTSA) and salt (i.e. N,N-diethylenethanol ammonium chloride) as a novel recyclable catalyst (DEAC-DES). The

  16. Recycling wood pulping chemicals by molten salt electrolysis: cyclic voltammetry of mixtures containing Na 2 CO 3 and Na 2 SO 4

    Microsoft Academic Search

    R. Wartena; J. Winnick; P. H. Pfromm

    2002-01-01

    We are investigating a novel electrochemical pathway for efficient recycling of inorganic chemicals from the kraft pulping process. To analyse this process, cyclic voltammetry was conducted on molten salts containing sodium carbonate, or sodium carbonate and sodium sulfate on gold and nickel\\/nickel oxide electrodes. Pure sodium carbonate at 860 °C was determined to exhibit oxidation to carbon dioxide and oxygen.

  17. New eutectic ionic liquids for lipase activation and enzymatic preparation of biodiesel†

    PubMed Central

    Zhao, Hua; Baker, Gary A.; Holmes, Shaletha

    2012-01-01

    The enzymatic preparation of biodiesel has been hampered by the lack of suitable solvents with desirable properties such as high lipase compatibility, low cost, low viscosity, high biodegradability, and ease of product separation. Recent interest in using ionic liquids (ILs) as advanced reaction media has led to fast reaction rates and high yields in the enzymatic synthesis of biodiesel. However, conventional (i.e., cation–anion paired) ILs based on imidazolium and other quaternary ammonium salts remain too expensive for wide application at industrial scales. In this study, we report on newly-synthesized eutectic ILs derived from choline acetate or choline chloride coupled with biocompatible hydrogen-bond donors, such as glycerol. These eutectic solvents have favorable properties including low viscosity, high biodegradability, and excellent compatibility with Novozym® 435, a commercial immobilized Candida antarctica lipase B. Furthermore, in a model biodiesel synthesis system, we demonstrate high reaction rates for the enzymatic transesterification of Miglyol® oil 812 with methanol, catalyzed by Novozym® 435 in choline acetate/glycerol (1 : 1.5 molar ratio). The high conversion (97%) of the triglyceride obtained within 3 h, under optimal conditions, suggests that these novel eutectic solvents warrant further exploration as potential media in the enzymatic production of biodiesel. PMID:21283901

  18. Two-stage eutectic metal brushes

    DOEpatents

    Hsu, John S (Oak Ridge, TN) [Oak Ridge, TN

    2009-07-14

    A two-stage eutectic metal brush assembly having a slip ring rigidly coupled to a shaft, the slip ring being electrically coupled to first voltage polarity. At least one brush is rigidly coupled to a second ring and slidingly engaged to the slip ring. Eutectic metal at least partially fills an annulus between the second ring and a stationary ring. At least one conductor is rigidly coupled to the stationary ring and electrically coupled to a second voltage polarity. Electrical continuity is maintained between the first voltage polarity and the second voltage polarity. Periodic rotational motion is present between the stationary ring and the second ring. Periodic rotational motion is also present between the brush and the slip ring.

  19. The Effect of Salt Stoichiometry on Protein-Salt Interactions Determined by Ternary Diffusion in Aqueous Solutions

    E-print Network

    Annunziata, Onofrio

    The Effect of Salt Stoichiometry on Protein-Salt Interactions Determined by Ternary Diffusion of salt stoichiometry on the transport properties of lysozyme-salt aqueous mixtures. We find that the two cross-diffusion coefficients are very sensitive to salt stoichiometry. One of the cross

  20. ac impedance measurements of molten salt thermal batteries

    NASA Astrophysics Data System (ADS)

    Singh, Pritpal; Guidotti, Ronald A.; Reisner c, David

    Non-destructive testing of thermal batteries without activating them is a challenging proposition. Molten salt thermal batteries are activated by raising their temperature to above the melting point of the salt constituting the electrolyte. One approach that we have considered is to raise the temperature of the molten salt electrolyte to a temperature below the melting point so that the battery does not get activated yet may provide sufficient mobility of the ionic species to be able to obtain some useful ac impedance measurements. This hypothesis was put to the test for two Li(Si)/FeS 2 molten salt batteries with two electrolytes of different melting points—a standard LiCl-KCl eutectic that melts at 352 °C and a LiBr-KBr-LiCl eutectic with a melting point of 319 °C. ac impedance measurements as a function of frequency and temperature below the melting point are presented for single cells and batteries.

  1. Ionothermal synthesis of two oxalate-bridged lanthanide(III) chains with slow magnetization relaxation by using a deep eutectic solvent.

    PubMed

    Meng, Yan; Liu, Jun-Liang; Zhang, Ze-Min; Lin, Wei-Quan; Lin, Zhuo-Jia; Tong, Ming-Liang

    2013-09-28

    Two novel isostructural oxalate-bridged lanthanide(III) chains, (choline)[Ln(ox)(H2O)3Cl]Cl·H2O (Ln = Dy/Er), were first obtained ionothermally by using a choline chloride-oxalic acid eutectic mixture as both solvent and structure-directing agent, both of which show field-induced slow relaxation of magnetization. PMID:23903323

  2. Fluorescence Spectroscopic Studies of (Amide + Electrolyte) Deep Eutectic Systems Biswajit Guchhait and Ranjit Biswas*

    E-print Network

    Biswas, Ranjit

    glass transition. Keywords: deep eutectic solvents, fluorescence measurements, viscosity decoupling Refs liquid at or near room temperature. These systems are known as deep eutectic solvents (DES) and exhibit1 Fluorescence Spectroscopic Studies of (Amide + Electrolyte) Deep Eutectic Systems Biswajit

  3. Thermal unfolding and refolding of lysozyme in deep eutectic solvents and their aqueous dilutions.

    PubMed

    Esquembre, Rocio; Sanz, Jesus M; Wall, J Gerard; del Monte, Francisco; Mateo, C Reyes; Ferrer, M Luisa

    2013-07-21

    The stability of hen's egg white lysozyme in different choline chloride-based pseudo-concentrated and neat deep eutectic solvents (DESs) has been studied by means of intrinsic fluorescence and CD spectroscopy. Thermal unfolding experiments carried out in non-diluted urea:choline chloride and glycerol:choline chloride eutectic solvents (UCCl-DES and GCCl-DES, respectively) showed the accumulation at certain temperatures of discrete, partially folded intermediates that displayed a high content of secondary structure and a disrupted tertiary structure. Reversibility of the unfolding process was incomplete in these circumstances, with the urea-based DES showing higher protein structure destabilization upon thermal treatment. On the other hand, aqueous dilution of the eutectic mixtures allowed the recovery of a reversible, two-state denaturation process. Lysozyme activity was also affected in neat and pseudo-concentrated GCCl-DES, with an increasing recovery of activity upon aqueous dilution, and full restoration after DES removal through extensive dialysis. These results suggest that protein interactions at room temperature are reversible and depend on the DES components and on the aqueous content of the original DES dilution. PMID:23722327

  4. Solubilization of Genistein in Poly(Ethylene Glycol) via Eutectic Crystal Melting

    NASA Astrophysics Data System (ADS)

    Buddhiranon, Sasiwimon; Kyu, Thein

    2012-02-01

    Genistein (5,7,4'-trihydroxyisoflavone) is a phytoestrogen found in soybean. It possesses various biological/pharmacological functions, e.g., tyrosine kinase inhibitory, anticarcinogenic, antioxidant, anti-inflammatory, and anti-microbial activities. However, genistein has poor water solubility and skin permeability, which have seemingly prohibited the progress to preclinical evaluation. Eutectic melting approach has been performed as a means of solubilizing genistein in poly(ethylene glycol) (PEG). Eutectic phase diagrams of blends containing genistein and PEG having three different molecular weights, i.e., 44k, 7k, and 500 g/mol, were established by means of DSC and compared with the theoretical liquidus and solidus lines, calculated self-consistently by taking into consideration all interactions including amorphous-amorphous, crystal-amorphous, amorphous-crystal, and crystal-crystal interactions. The eutectic temperatures were found to decrease with decreasing molecular weight of PEG. Guided by the phase diagram, it was found that genistein can be dissolved in PEG500 up to ˜7 wt% at room temperature. More importantly, the solubility of genistein in PEG can be improved to meet the end-use criteria of the PEG/genistein mixtures.

  5. Introducing deep eutectic solvents as biorenewable media for Au(I)-catalysed cycloisomerisation of ?-alkynoic acids: an unprecedented catalytic system.

    PubMed

    Rodríguez-Álvarez, María J; Vidal, Cristian; Díez, Josefina; García-Álvarez, Joaquín

    2014-11-01

    Cycloisomerisation of ?-alkynoic acids into cyclic enol-lactones was conveniently performed, for the first time, in the eutectic mixture 1ChCl/2Urea under standard bench experimental conditions (at room temperature, under air and in the absence of co-catalysts) by using a new iminophosphorane-Au(I) complex as the catalyst. Furthermore, the catalytic system could be recycled up to four runs. PMID:25215857

  6. Unexpected lateral-lithiation-induced alkylative ring opening of tetrahydrofurans in deep eutectic solvents: synthesis of functionalised primary alcohols.

    PubMed

    Sassone, Francesca C; Perna, Filippo M; Salomone, Antonio; Florio, Saverio; Capriati, Vito

    2015-05-26

    o-Tolyl-substituted tetrahydrofurans undergo highly regioselective ring opening with the concomitant formation of new C-C bonds as the result of a lateral lithiation reaction. This reaction provides a new method for the synthesis of functionalised primary alcohols and can be run directly in protic eutectic mixtures as benign reaction media at 0 °C and under air, competitively with protonolysis. PMID:25959580

  7. A facile approach to prepare a dual functionalized DNA based material in a bio-deep eutectic solvent.

    PubMed

    Mondal, Dibyendu; Bhatt, Jitkumar; Sharma, Mukesh; Chatterjee, Shruti; Prasad, Kamalesh

    2014-04-18

    DNA (Salmon testes) was functionalized by Fe3O4 nanoparticles and protonated layered dititanate sheets (H2·Ti2O5·H2O) in a mixture of choline chloride and ethylene glycol (a deep eutectic solvent) to yield a hybrid material having magnetic and antibacterial properties. Ti sheets were found to interact with the phosphate moieties, while Fe interacted with the base pair of DNA in the hybrid material. PMID:24609301

  8. Mixed salt crystallisation fouling

    Microsoft Academic Search

    A Helalizadeh; H Müller-Steinhagen; M Jamialahmadi

    2000-01-01

    The main purpose of this investigation was to study the mechanisms of mixed salt crystallisation fouling on heat transfer surfaces during convective heat transfer and sub-cooled flow boiling. To date, no investigations on the effects of operating parameters on the deposition of mixtures of calcium sulphate and calcium carbonate, which are the most common constituents of scales formed on heat

  9. Improved solubility of DNA in recyclable and reusable bio-based deep eutectic solvents with long-term structural and chemical stability.

    PubMed

    Mondal, Dibyendu; Sharma, Mukesh; Mukesh, Chandrakant; Gupta, Vishal; Prasad, Kamalesh

    2013-10-25

    The solubility of DNA in bio-based deep eutectic solvents (DESs) consisting of mixtures of choline chloride with levulinic acid, glycerol, ethylene glycol, sorbitol and resorcinol was investigated. The macromolecule was found to be soluble and chemically and structurally stable in DESs consisting of mixtures containing glycerol and ethylene glycol. Furthermore recyclability of the DESs was demonstrated over three consecutive reuses in DNA dissolution. PMID:24022824

  10. A solar-thermal energy harvesting scheme: enhanced heat capacity of molten HITEC salt mixed with Sn/SiOx core-shell nanoparticles

    NASA Astrophysics Data System (ADS)

    Lai, Chih-Chung; Chang, Wen-Chih; Hu, Wen-Liang; Wang, Zhiming M.; Lu, Ming-Chang; Chueh, Yu-Lun

    2014-04-01

    We demonstrated enhanced solar-thermal storage by releasing the latent heat of Sn/SiOx core-shell nanoparticles (NPs) embedded in a eutectic salt. The microstructures and chemical compositions of Sn/SiOx core-shell NPs were characterized. In situ heating XRD provides dynamic crystalline information about the Sn/SiOx core-shell NPs during cyclic heating processes. The latent heat of ~29 J g-1 for Sn/SiOx core-shell NPs was measured, and 30% enhanced heat capacity was achieved from 1.57 to 2.03 J g-1 K-1 for the HITEC solar salt without and with, respectively, a mixture of 5% Sn/SiOx core-shell NPs. In addition, an endurance cycle test was performed to prove a stable operation in practical applications. The approach provides a method to enhance energy storage in solar-thermal power plants.We demonstrated enhanced solar-thermal storage by releasing the latent heat of Sn/SiOx core-shell nanoparticles (NPs) embedded in a eutectic salt. The microstructures and chemical compositions of Sn/SiOx core-shell NPs were characterized. In situ heating XRD provides dynamic crystalline information about the Sn/SiOx core-shell NPs during cyclic heating processes. The latent heat of ~29 J g-1 for Sn/SiOx core-shell NPs was measured, and 30% enhanced heat capacity was achieved from 1.57 to 2.03 J g-1 K-1 for the HITEC solar salt without and with, respectively, a mixture of 5% Sn/SiOx core-shell NPs. In addition, an endurance cycle test was performed to prove a stable operation in practical applications. The approach provides a method to enhance energy storage in solar-thermal power plants. Electronic supplementary information (ESI) available: Detailed experimental results are included for the following: SEM images of the HITEC molten salt with and without a mixture of Sn/SiOx core-shell NPs; statistical diameter distribution of pure Sn and Sn/SiOx core-shell NPs; the HAADF image and EDS linescan profile of a Sn/SiOx core-shell NP; XRD analysis for Sn NPs annealing at different heating temperatures; the XRD spectra of Sn/SiOx core-shell NPs before and after RTA for the shell protection test. See DOI: 10.1039/c3nr06810b

  11. Continuous Crystallization of Urea-Water Mixture

    NASA Astrophysics Data System (ADS)

    Hokamura, Taku; Ohkubo, Hidetoshi; Watanabe, Satoshi; Seki, Mitsuo; Murakoshi, Hiromichi

    Ice slurries have been used as environmentally-friendly secondary refrigerants. In addition to such ice slurries, aqueous solutions in slurry-state have also been put to practical use at temperatures below 0 oC. Urea-water mixture is a multi-component substance that has a eutectic point. If we can form a two-phase fluid substance by the liquid-solid phases at the eutectic point, it can be used as a fluid latent heat storage material, which will maintain the secondary refrigerant in a heat exchanger at constant temperature. In the present study, we propose a urea-water mixture as a novel functional thermal fluid that can be used as a fluid latent heat material. To demonstrate its feasibility, we first measured the latent heat and density of a urea-water mixture, and then used a counter-flow double tube heat exchanger to produce a liquid-solid two-phase flow of the urea-water mixture. This work demonstrates that it is possible to make a fluid latent heat storage material continuously from an aqueous solution at the eutectic point by flowing it through a double tube heat exchanger equipped with a stirrer.

  12. Molten Salt Fuel Version of Laser Inertial Fusion Fission Energy (LIFE)

    SciTech Connect

    Moir, R W; Shaw, H F; Caro, A; Kaufman, L; Latkowski, J F; Powers, J; Turchi, P A

    2008-10-24

    Molten salt with dissolved uranium is being considered for the Laser Inertial Confinement Fusion Fission Energy (LIFE) fission blanket as a backup in case a solid-fuel version cannot meet the performance objectives, for example because of radiation damage of the solid materials. Molten salt is not damaged by radiation and therefore could likely achieve the desired high burnup (>99%) of heavy atoms of {sup 238}U. A perceived disadvantage is the possibility that the circulating molten salt could lend itself to misuse (proliferation) by making separation of fissile material easier than for the solid-fuel case. The molten salt composition being considered is the eutectic mixture of 73 mol% LiF and 27 mol% UF{sub 4}, whose melting point is 490 C. The use of {sup 232}Th as a fuel is also being studied. ({sup 232}Th does not produce Pu under neutron irradiation.) The temperature of the molten salt would be {approx}550 C at the inlet (60 C above the solidus temperature) and {approx}650 C at the outlet. Mixtures of U and Th are being considered. To minimize corrosion of structural materials, the molten salt would also contain a small amount ({approx}1 mol%) of UF{sub 3}. The same beryllium neutron multiplier could be used as in the solid fuel case; alternatively, a liquid lithium or liquid lead multiplier could be used. Insuring that the solubility of Pu{sup 3+} in the melt is not exceeded is a design criterion. To mitigate corrosion of the steel, a refractory coating such as tungsten similar to the first wall facing the fusion source is suggested in the high-neutron-flux regions; and in low-neutron-flux regions, including the piping and heat exchangers, a nickel alloy, Hastelloy, would be used. These material choices parallel those made for the Molten Salt Reactor Experiment (MSRE) at ORNL. The nuclear performance is better than the solid fuel case. At the beginning of life, the tritium breeding ratio is unity and the plutonium plus {sup 233}U production rate is {approx}0.6 atoms per 14.1 MeV neutron.

  13. Solidification of eutectic system alloys in space (M-19)

    NASA Technical Reports Server (NTRS)

    Ohno, Atsumi

    1993-01-01

    It is well known that in the liquid state eutectic alloys are theoretically homogeneous under 1 g conditions. However, the homogeneous solidified structure of this alloy is not obtained because thermal convection and non-equilibrium solidification occur. The present investigators have clarified the solidification mechanisms of the eutectic system alloys under 1 g conditions by using the in situ observation method; in particular, the primary crystals of the eutectic system alloys never nucleated in the liquid, but instead did so on the mold wall, and the crystals separated from the mold wall by fluid motion caused by thermal convection. They also found that the equiaxed eutectic grains (eutectic cells) are formed on the primary crystals. In this case, the leading phase of the eutectic must agree with the phase of the primary crystals. In space, no thermal convection occurs so that primary crystals should not move from the mold wall and should not appear inside the solidified structure. Therefore no equiaxed eutectic grains will be formed under microgravity conditions. Past space experiments concerning eutectic alloys were classified into two types of experiments: one with respect to the solidification mechanisms of the eutectic alloys and the other to the unidirectional solidification of this alloy. The former type of experiment has the problem that the solidified structures between microgravity and 1 g conditions show little difference. This is why the flight samples were prepared by the ordinary cast techniques on Earth. Therefore it is impossible to ascertain whether or not the nucleation and growth of primary crystals in the melt occur and if primary crystals influence the formation of the equiaxed eutectic grains. In this experiment, hypo- and hyper-eutectic aluminum copper alloys which are near eutectic point are used. The chemical compositions of the samples are Al-32.4mass%Cu (Hypo-eutectic) and Al-33.5mass%Cu (hyper-eutectic). Long rods for the samples are cast by the Ohno Continuous Casting Process and they show the unidirectionally solidified structure. Each flight and ground sample was made of these same rods. The dimensions of all samples are 4.5 mm in diameter and 23.5 mm in length. Each sample is put in a graphite capsule and then vacuum sealed in a double silica ampoule. Then the ampoule is put in the tantalum cartridge and sealed by electron beam welding. For onbard experiments, a Continuous Heating Furnance (CHF) will be used for melting and solidifying samples under microgravity conditions. Six flight samples will be used. Four samples are hypo-eutectic and two are hyper-eutectic alloys. The surface of the two hypo-eutectic alloy samples are covered with aluminum oxide film to prevent Marangoni convection expected under microgravity conditions. Each sample will be heated to 700 C and held at that temperature for 5 min. After that the samples will be allowed to cool to 500 C in the furnace and they will be taken out of the furnace for He gas cooling. The heating and cooling diagrams for the flight experiments are shown. After collecting the flight samples, the solidified structures of the samples will be examined and the mechanisms of eutectic solidification under microgravity conditions will be determined. It is likely that successful flight experiment results will lead to production of high quality eutectic alloys and eutectic composite materials in space.

  14. Eutectic growth in unidirectionally solidified Fe-Cr-Ni alloy

    SciTech Connect

    Okane, Toshimitsu; Umeda, Takateru [Univ. of Tokyo (Japan)

    1998-12-31

    In this report, transition of solidified phases for directionally solidified Fe-Cr-Ni alloys has been investigated in low growth rate range by using Bridgman type furnace. The ferritic-austenite eutectic growth has been confirmed like a plane front growth of ferrite single phase under low growth rate condition. The transition velocity between eutectic and ferrite cell growth has a good agreement with the result of calculation based on the phase selection criterion and the interface temperature calculation for ferrite, austenite and eutectic phases. These results show that the phase prediction by calculating interface temperature can be applied not only to competitive growth between single phases like peritectic systems, but also to eutectic systems. Furthermore, under the condition of eutectic coupled growth to be occurred in steady state, the changes of solidified phases and their morphologies in the initial transient are discussed.

  15. Eutectic mixed monolayers in equilibrium with phospholipid-bilayers and triolein-liquid phase.

    PubMed Central

    Handa, T; Saito, H; Miyajima, K

    1993-01-01

    Triolein (TO) and phospholipids (egg yolk phosphatidylcholine, egg yolk phosphatidylethanolamine, and bovine brain phosphatidylserine) had low mutual solubilities and separated into the TO-liquid phase and phospholipid-bilayers. Spreading pressures of the TO-phospholipid mixture (i.e., surface pressures of the mixed monolayer in equilibrium with the phase-separating lipid mixture) at the air/saline interface were independent of the lipid composition. On the other hand, collapse pressures of the mixed monolayer of TO and phospholipid (i.e., surface pressures of the mixed monolayer in equilibrium with the TO-liquid phase) at the interface changed with the monolayer composition and were lower than the spreading pressure. The experimental data indicated the spreading and collapse pressures as offering a phase diagram for the presence of equilibrium between the mixed monolayer, the phospholipid-bilayers and the TO-liquid phase. The diagram showed that TO and the phospholipids were miscible in the mixed monolayer, forming an eutectic mixed monolayer. When the mixed monolayer initially had the eutectic composition, no collapse of the monolayer was detected until the surface pressure reached the value of the spreading pressure. No specific complex between TO and the phospholipid is required to explain the stability and collapse of the mixed monolayers. The bulk immiscibility of the lipids elucidated by the spreading pressure-measurements, immediately leads to the phase behaviors observed. PMID:8369406

  16. Thermodynamical and Optical Studies of Ternary Mixtures of 4-n-Heptyloxy Benzoic Acid, 4-n-Decyloxy Benzoic Acid, and 5-Cholesten-3ß-ol 3-octanoate

    Microsoft Academic Search

    R. Dhar; M. B. Pandey; V. K. Agrawal

    2004-01-01

    Binary eutectic mixture of 4-n-heptyloxybenzoic acid (HOBA) and 4-n-decyloxybenzoic acid (DOBA) shows smectic C (SmC) and nematic (N) phases over a wide temperature range. 5-cholesten-3?-ol 3-octanoate(ChO), which has monotropic chiral nematic (N?) phase, has been added as third component in the eutectic bi-component mixture (BCM) of HOBA-DOBA in different mole ratios. Transition temperatures and enthalpies of the ternary mixtures have

  17. Making Bath Salts for Mother's Day, a Primary Chemistry Lesson

    NSDL National Science Digital Library

    This activity is a guided discovery where students make chemical mixtures using sodium, learn about the Periodic Table, view salt under a microscope, and have a final result of bath salts for the bathtub

  18. Deep eutectic solvents as novel extraction media for protein partitioning.

    PubMed

    Zeng, Qun; Wang, Yuzhi; Huang, Yanhua; Ding, Xueqin; Chen, Jing; Xu, Kaijia

    2014-05-21

    Four kinds of green deep eutectic solvent (DES) were synthesized, including choline chloride (ChCl)-urea, tetramethylammonium chloride (TMACl)-urea, tetrapropylammonium bromide (TPMBr)-urea and ChCl-methylurea. An aqueous two-phase system (ATPS) based ChCl-urea DES was studied for the first time for the extraction of bovine serum albumin (BSA). Single factor experiments proved that the extraction efficiency of BSA was influenced by the mass of the DES, concentration of K2HPO4 solution, separation time and extraction temperature. The optimum conditions were determined through an orthogonal experiment with the four factors described above. The results showed that under the optimum conditions, the average extraction efficiency could reach up to 99.94%, 99.72%, 100.05% and 100.05% (each measured three times). The relative standard deviations (RSD) of extraction efficiencies in precision, repeatability and stability experiments were 0.5533% (n = 5), 0.8306% (n = 5) and 0.9829% (n = 5), respectively. UV-vis and FT-IR spectra confirmed that there were no chemical interactions between BSA and the DES in the extraction process, and the CD spectra proved that the conformation of BSA did not change after extraction. The conductivity, DLS and TEM were combined to investigate the microstructure of the top phase and the possible mechanism for the extraction. The results showed that hydrophobic interactions, hydrogen bonding interactions and the salting-out effect played important roles in the transfer process, and the aggregation and surrounding phenomenon were the main driving forces for the separation. All of these results proved that ionic liquid (IL)-based ATPSs could potentially be substituted with DES-based ATPSs to offer new possibilities in the extraction of proteins. PMID:24699681

  19. CORROSION STUDIES FOR A FUSED SALT-LIQUID METAL EXTRACTION PROCESS FOR THE LIQUID METAL FUEL REACTOR

    Microsoft Academic Search

    H. Susskind; F. B. Hill; L. Green; S. Kalish; L. E. Kukacka; W. E. McNulty; E. Jr. Wirsing

    1960-01-01

    Corrosion screening tests were carried out on potential materials of ;\\u000a construction for use in a fused salt-liquid metal extraction process plant. The ;\\u000a corrodents of interest were NaCl--KCl-- MgCl eutectic, LiCl--KCl eutectic, ;\\u000a Bi-- U fuel, and BiCl, either separately or in various combinations. ;\\u000a Screening tests to determine the resistance of a wide range of commercial alloys ;

  20. Eutectic propeties of primitive Earth's magma ocean

    NASA Astrophysics Data System (ADS)

    Lo Nigro, G.; Andrault, D.; Bolfan-Casanova, N.; Perillat, J.-P.

    2009-04-01

    It is widely accepted that the early Earth was partially molten (if not completely) due to the high energy dissipated by terrestrial accretion [1]. After core formation, subsequent cooling of the magma ocean has led to fractional crystallization of the primitive mantle. The residual liquid corresponds to what is now called the fertile mantle or pyrolite. Melting relations of silicates have been extensively investigated using the multi-anvil press, for pressures between 3 and 25 GPa [2,3]. Using the quench technique, it has been shown that the pressure affects significantly the solidus and liquidus curves, and most probably the composition of the eutectic liquid. At higher pressures, up to 65 GPa, melting studies were performed on pyrolite starting material using the laser-heated diamond anvil cell (LH-DAC) technique [4]. However, the quench technique is not ideal to define melting criteria, and furthermore these studies were limited in pressure range of investigation. Finally, the use of pyrolite may not be relevant to study the melting eutectic temperature. At the core-mantle boundary conditions, melting temperature is documented by a single data point on (Mg,Fe)2SiO4 olivine, provided by shock wave experiments at around 130-140 GPa [5]. These previous results present large uncertainties of ~1000 K. The aim of this study is to determine the eutectic melting temperature in the chemically simplified system composed of the two major lower mantle phases, the MgSiO3 perovskite and MgO periclase. We investigated melting in-situ using the laser-heated diamond anvil cell coupled with angle dispersive X-ray diffraction at the ID27 beamline of the ESRF [6]. Melting relations were investigated in an extended P-T range comparable to those found in the Earth's lower mantle, i.e. from 25 to 120 GPa and up to more than 5000 K. Melting was evidenced from (a) disappearance of one of the two phases in the diffraction pattern, (b) drastic changes of the diffraction image itself, and/or (c) appearance of a broad band of diffuse X-ray scattering associated to the presence of silicate liquid. The pressure evolution of the eutectic temperature is found below the melting curve of pure MgSiO3 perovskite [7] for more than 500 K and also below the solidus curve of pyrolite [4] for 100-200 K at 60 GPa. References [1] B. T. Tonks, H. J. Melosh, Journal of Geophysical Research 98 5319 (1993). [2] Litasov, K., and Ohtani, E. Physics of The Earth and Planetary Interiors, 134(1-2), 105-127, (2002). [3] E. Ito, A. Kubo, T. Katsura et al., Phys. Earth Planet. Inter. 143-144 397 (2004). [4] A. Zerr, R. Boehler, Nature 506-508 (1994). [5] J. A. Akins, S. N. Luo, P. D. Asimov et al., Geophys. Res. Lett. 31 doi:10.1029/2004GL020237 (2004). [6] Schultz et al. International Journal of High Pressure Research. 25, 1, 71-83 (2005). [7] Zerr, A. and Boehler, R. Science, 262, 553-555 (1993).

  1. Physical properties of oils and mixtures of oils

    Microsoft Academic Search

    R. E. Timms

    1985-01-01

    The physical properties of palm, palm kernel and coconut oils are reviewed and compared and contrasted with the properties\\u000a of other oils and fats. More information is available for palm oil than for the other two. The properties of mixtures of the\\u000a oils also are considered, especially mixtures of palm and palm kernel oils in which a eutectic interaction occurs.

  2. Shear Strength of Eutectic Sn-Bi Lead-Free Solders After Corrosion Testing and Thermal Aging

    NASA Astrophysics Data System (ADS)

    Mostofizadeh, Milad; Pippola, Juha; Frisk, Laura

    2014-05-01

    Low-cost manufacturing in the electronics industry is becoming more demanding, particularly in the production of consumer electronics. Such manufacturing processes require reliable and low-cost lead-free solders. Among the low temperature lead-free solders, eutectic Sn-Bi solder has attracted a great deal of interest since it offers good reliability comparable to that of Sn-Pb solders. In this paper, the shear strength of eutectic 42Sn-58Bi (wt.%) lead-free solder was studied using combinations of environmental tests including thermal aging at 100 °C, salt spray test, and a sequential combination of these tests. Microstructural studies on samples were performed at different time intervals of testing. To study the effect of salt spray and thermal aging on the mechanical reliability, shear testing was performed on the samples. Failure analysis including fractography on samples was conducted at different time intervals using a scanning electron microscope. Considerable corrosion was observed after the salt spray test. This was found to have a significant effect on the shear strength of the solder joints. Additionally, thermal aging was found to cause coarsening and to increase the thickness of intermetallic layers. This was also found to adversely affect the shear strength. The combination test was found to have the most significant effect, as the lowest shear strengths were seen after this testing.

  3. Use of Microgravity to Control the Microstructure of Eutectics

    NASA Technical Reports Server (NTRS)

    Wilcox. William R.; Regel, Liya L.

    1999-01-01

    This grant began in June of 1996. Its long term goal is to be able to control the microstructure of directionally solidified eutectic alloys, through an improved understanding of the influence of convection. The primary objective of the projects in the present grant is to test hypotheses for the reported influence of microgravity on the microstructure of eutectics. The prior experimental results on the influence of microgravity on the microstructure of eutectics have been contradictory. With lamellar eutectics, microgravity had a negligible effect on the microstructure. Microgravity experiments with fibrous eutectics sometimes showed a finer microstructure and sometimes a coarser microstructure. Most research has been done on the MnBi/Bi rod-like eutectic. Larson and Pirich obtained a two-fold finer microstructure both from microgravity and by use of a magnetic field to quench buoyancy-driven convection. Smith, on the other hand, observed no change in microgravity. Prior theoretical work at Clarkson University showed that buoyancy-driven convection in the vertical Bridgman configuration is not vigorous enough to alter the concentration field in front of a growing eutectic sufficiently to cause a measurable change in microstructure. We assumed that the bulk melt was at the eutectic composition and that freezing occurred at the extremum, i.e. with minimum total undercooling at the freezing interface. There have been four hypotheses attempting to explain the observed changes in microstructure of fibrous eutectics caused by convection: I .A fluctuating freezing rate, combined with unequal kinetics for fiber termination and branching. 2. Off-eutectic composition, either in the bulk melt due to an off-eutectic feed or at the freezing interface because of departure from the extremum condition. 3. Presence of a strong habit modifying impurity whose concentration at the freezing interface would be altered by convection. At the beginning of the present grant, we favored the first of these hypotheses and set out to test it both experimentally and theoretically. We planned the following approaches: I .Pass electric current pulses through the MnBi/Bi eutectic during directional solidification in order to produce an oscillatory freezing rate. 2. Directionally solidify the MnBi/Bi eutectic on Mir using the QUELD II gradient freeze furnace developed by Professor Smith at Queen's University. 3. Select another fibrous eutectic system for investigation using the Accelerated Crucible Rotation Technique to introduce convection. 4. Develop theoretical models for eutectic solidification with an oscillatory freezing rate. Because of the problems with Mir, we substituted ground-based experiments at Queen's University with QUELD II vertical and horizontal, with and without vibration of the furnace. The Al-Si system was chosen for the ACRT experiments. Three related approaches were used to model eutectic solidification with an oscillatory freezing rate. A sharp interface model was used to calculate composition oscillations at the freezing interface in response to imposed freezing rate oscillations.

  4. Corrosion of ODS steels in lead–bismuth eutectic

    Microsoft Academic Search

    P. Hosemann; H. T. Thau; A. L. Johnson; S. A. Maloy; N. Li

    2008-01-01

    Oxide dispersion strengthened (ODS) ferritic steels are advanced materials being developed for high temperature applications. Their properties (high temperature strength, creep resistance, corrosion\\/oxidation resistance) make them potentially usable for high temperature applications in liquid metal cooled systems like liquid lead–bismuth eutectic cooled reactors and spallation sources. Corrosion tests on five different ODS alloys were performed in flowing liquid lead–bismuth eutectic

  5. Nanostructures from directionally solidified NiAl–W eutectic alloys

    Microsoft Academic Search

    Achim Walter Hassel; Andrew Jonathan Smith; Srdjan Milenkovic

    2006-01-01

    A directionally solidified eutectic NiAl–W alloy was employed as a source for NiAl nanopore arrays, W-nanowire arrays and W-nanowires. The NiAl–W eutectic alloy containing 1.5at.% W. A growth rate of 30mmh?1 was used at a temperature gradient of 40Kcm?1 in a Bridgman-type directional solidification furnace. A combined stability diagram was derived from the Pourbaix diagrams of the three elements involved

  6. Preparation of directionally solidified eutectics in some oxohalide systems

    SciTech Connect

    Chemekova, T.Yu.; Udalov, Yu.P.

    1987-09-01

    Directionally solidified eutectics of systems formed by oxides and halides can be employed for developing materials with anisotropic properties. Preparation of directionally solidified eutectics by the method of zone melting with a heater submerged in the melt makes it possible to monitor visually the entire growth process. This method is apparently optimal, since it makes it possible to control the temperature gradient and the solidification rate over wide limits.

  7. The microstructure of MnBi/Bi eutectic alloys

    NASA Technical Reports Server (NTRS)

    Ravishankar, P. S.; Wilcox, W. R.; Larson, D. J.

    1980-01-01

    Directionally solidified eutectic alloys of the system MnBi/Bi have been investigated with reference to the dependence of the fiber spacing on the growth rate and the interfacial temperature gradient. It is found that the fiber spacing varies as the inverse square root of the growth rate and does not depend on the temperature gradient in contrast to the claims that all faceted/non-faceted eutectics should show a temperature gradient influence.

  8. Characterization of low-melting electrolytes for potential geothermal borehole power supplies: The LiBr-KBr-LiF eutectic

    SciTech Connect

    Guidotti, R.A.; Reinhardt, F.W.

    1998-05-01

    The suitability of modified thermal-battery technology for use as a potential power source for geothermal borehole applications is under investigation. As a first step, the discharge processes that take place in LiSi/LiBr-KBr-LiF/FeS{sub 2} thermal cells were studied at temperatures of 350 C and 400 C using pelletized cells with immobilized electrolyte. Incorporation of a reference electrode allowed the relative contribution of each electrode to the overall cell polarization to be determined. The results of single-cell tests are presented, along with preliminary data for cells based on a lower-melting CsBr-LiBr-KBr eutectic salt.

  9. Regular rod-like eutectic spacing selection during directional solidified NiAl–9Mo eutectic in situ composite

    Microsoft Academic Search

    Jianfei Zhang; Jun Shen; Zhao Shang; Zhourong Feng; Lingshui Wang; Hengzhi Fu

    2011-01-01

    NiAl–9Mo (at%) eutectic alloy was produced by a Bridgman type crystal growing facility with Zone Melting Liquid Metal Cooling technique at the growth rate range from 60 to 200?m\\/s. The variation of rod eutectic spacing with growth rates was characterized. Statistical distributions of spacings at each growth rate were also determined. It was confirmed that the relationship between growth rate

  10. Applicability evaluation of Deep Eutectic Solvents-Cellulase system for lignocellulose hydrolysis.

    PubMed

    Gunny, Ahmad Anas Nagoor; Arbain, Dachyar; Nashef, Enas Muen; Jamal, Parveen

    2015-04-01

    Deep Eutectic Solvents (DESs) have recently emerged as a new generation of ionic liquids for lignocellulose pretreatment. However, DESs contain salt components which tend to inactivate cellulase in the subsequent saccharification process. To alleviate this problem, it is necessary to evaluate the applicability of the DESs-Cellulase system. This was accomplished in the present study by first studying the stability of cellulase in the presence of selected DESs followed by applicability evaluation based on glucose production, energy consumption and kinetic performance. Results showed that the cellulase was able to retain more than 90% of its original activity in the presence of 10% (v/v) for glycerol based DES (GLY) and ethylene glycol based DES (EG). Furthermore, both DESs system exhibited higher glucose percentage enhancement and lower energy consumption as compared to diluted alkali system. Among the two DESs studied, EG showed comparatively better kinetic performance. PMID:25661309

  11. Are deep eutectic solvents benign or toxic?

    PubMed

    Hayyan, Maan; Hashim, Mohd Ali; Hayyan, Adeeb; Al-Saadi, Mohammed A; AlNashef, Inas M; Mirghani, Mohamed E S; Saheed, Olorunnisola Kola

    2013-02-01

    In continuation of investigation for environmentally benign protocol for new solvents termed deep eutectic solvents (DESs), it is herein reported results concerning the toxicity and cytotoxicity of choline chloride (ChCl) based DESs with four hydrogen bond donors including glycerine, ethylene glycol, triethylene glycol and urea. The toxicity was investigated using two Gram positive bacteria Bacillus subtilis and Staphylococcus aureus, and two Gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The cytotoxicity effect was tested using the Artemia salina leach. It was found that there was no toxic effect for the tested DESs on all of the studied bacteria confirming their benign effects on these bacteria. Nevertheless, it was found that the cytotoxicity of DESs was much higher than their individual components (e.g. glycerine, ChCl) indicating that their toxicological behavior is different. For our best knowledge this is the first time that toxicity and cytotoxicity of DESs were studied. The toxicity and cytotoxicity of DESs varied depending on the structure of components. Careful usage of the terms non-toxicity and biodegradability must be considered. More investigation on this matter is required. PMID:23200570

  12. Influence of convection on eutectic microstructure

    NASA Technical Reports Server (NTRS)

    Baskaran, V.; Eisa, G. F.; Wilcox, W. R.

    1985-01-01

    When the MnBi-Bi eutectic is directionally solidified, it forms fibers of MnBi in a matrix of bismuth. When the material solidified in space at rates of 30 and 50 cm/hr, the average fiber spacing lambda was about one half of the value obtained in cases in which the same material solidified on earth. Neither an altered temperature gradient nor a fluctuating freezing rate are apparently responsible for the change in lambda, and the possibility is studied that natural convection increases lambda on earth by perturbing the compositional field in the melt ahead of the growing solid. A theoretical analysis is conducted along with some experiments. On the basis of the theoretical results for lamellar growth, it is concluded that the spacing lambda increases with increasing stirring, especially at small freezing rates. The experiments indicate that at low growth rates the cross-sectional area of the MnBi blades increases with increased stirring and with decreased growth rate.

  13. Luminescence and scintillation properties of Ce dope SrHfO3 based eutectics

    NASA Astrophysics Data System (ADS)

    Kamada, Kei; Kurosawa, Shunsuke; Shoji, Yasuhiro; Pejchal, Jan; Ohashi, Yuji; Yokota, Yuui; Yoshikawa, Akira

    2015-03-01

    Ce doped SrHfO3/SrAl12O19 eutectics were grown by the micro pulling down (?-PD) method and their directionally solidified eutectic system has been investigated. Investigations of obtained eutectic structure, luminescence and scintillation performances were also performed. Eutectics were grown at the speed of 0.60-0.90 mm/min. In the eutectics, Ce3+ 4f-5d emission was observed at 410 nm. The eutectics showed light yield of around 300 photon/5.5 meV alpha-ray by 241Am excitation. Scintillation decay time was 26.4 ns (45%) with slower decay component of 263 ns (55%).

  14. In-situ laser synthesis of Nd-Al-O coatings: the role of sublattice cations in eutectic formation.

    PubMed

    de Francisco, Isabel; Bea, Jose Antonio; Vegas, Angel; Carda, Juan Bautista; de la Fuente, German Francisco

    2015-02-01

    Neodymium aluminate coatings have been prepared in-situ by the laser zone melting (LZM) method, using a CO2 SLAB-type laser emitting at 10.6?µm. Polycrystalline Al2O3 commercial plates have been used as substrates, and coatings were prepared from the corresponding mixtures of powdered neodymium and aluminium oxides as starting materials. Microstructure, studied by SEM and phase composition, studied by XRD, proved the in-situ formation of a NdAlO3/NdAl11O18 eutectic. As a result, a well integrated composite coating was formed. Nanoindentation tests are consistent with excellent integration between coating and substrate. Structural similarities between the eutectic components within the coating, as well as between these and the substrate, are consistent with the crystallographic concepts proposed by Vegas (Ramos-Gallardo & Vegas, 1997), where cation sub-arrays play an important role governing metal oxide structures. These structure sublattices are suggested as the driving force behind eutectic oxide formation. PMID:25643721

  15. Particle-shape control of molten salt synthesized lead titanate

    Microsoft Academic Search

    Y. Ito; B. Jadidian; M. Allahverdi; A. Safari

    2000-01-01

    Lead titanate PbTiO3 (PT) powders with different morphologies were synthesized using a molten salt method. Amorphous PT powder was prepared from an aqueous nitrate solution, mixed with a eutectic of NaCl-KCl, and then heated at 850°C for 1 h. The effect of additives such as LiF, NaF and LiCl on the particle morphology and size of the derived PT was

  16. Bath Salts

    MedlinePLUS

    Synthetic cathinones, often called “bath salts,” are powerful, illegal, and can cause hallucinations and violent behavior, among other dangerous effects. Twitter Facebook RSS 582 Exposures Jan. 1, ...

  17. Salts & Solubility

    NSDL National Science Digital Library

    2012-12-27

    In this online interactive simulation, learners will add different salts to water and then watch the salts dissolve and achieve a dynamic equilibrium with solid precipitate. Learners will also compare the number of ions in NaCl to other slightly soluble salts, and they will relate the charges on ions to the number of ions in the formula of a salt. Learners will also learn how to calculate Ksp values. This activity includes an online simulation, sample learning goals, a teacher's guide, and translations in over 20 languages.

  18. Micro/macro solidification modeling of columnar eutectic growth

    NASA Astrophysics Data System (ADS)

    Judson, Ward Michael

    2000-11-01

    A general multidimensional model of alloy solidification is presented in which a velocity-dependent freezing temperature is coupled with the macroscale energy equation. The velocity dependence of the freezing temperature ( Tf˜v ) results from the microscale species diffusion for microstructures with coupled eutectic growth. At solidification rates ( ˜ 1--10 mm/s) that are representative of gravity permanent mold and die casting processes, consideration of the nonequilibrium conditions at the interface affects the prediction of the macroscale thermal field. Near-eutectic alloys freeze with a macroscopically discrete solid-liquid interface at a temperature below the equilibrium eutectic temperature. The model is illustrated with unidirectional solidification of a near-eutectic alloy in a finite domain and solved numerically with a fixed-grid Galerkin finite element method. The numerical algorithm includes inexpensive steps to compute the interface speed explicitly. By nondimensionalizing the governing equations the effect of coupled eutectic growth on heat transport is clearly identified so that the model's sensitivity to important parameters can be investigated. Additionally, the average eutectic spacing can be determined with the temperature field, rather than post-determination from a standard, uncoupled solution of the energy equation. The eutectic coupling results indicate that the predicted solid-liquid interface location lags behind the uncoupled solution; therefore, decreasing the amount of solid formed, increasing the total solidification time, and increasing the average eutectic spacing. A procedure is also illustrated for computing mechanical properties using experimental correlations and the computed interface velocity history. The effect of the eutectic undercooling is then studied in a square domain and a realistic three-dimensional production casting geometry. In order to address the multidimensional cases, a phase-field formulation is developed. Although the interface is considered to have a small finite thickness, the utility of the method is good for complex evolving solid-liquid interfaces and the velocity-dependent freezing temperature is satisfied implicitly. After demonstrating sufficient numerical accuracy, numerical results are presented for the square domain and three-dimensional geometry. Limitations of the phase-field method are discussed, and the conjugate heat transfer problem is studied to address boundary condition issues.

  19. Application of deep eutectic solvents in the extraction and separation of target compounds from various samples.

    PubMed

    Tang, Baokun; Zhang, Heng; Row, Kyung Ho

    2015-03-01

    Deep eutectic solvents, as a new type of eco-friendly solvent, have attracted increasing attention in chemistry for the extraction and separation of target compounds from various samples. To summarize the application of deep eutectic solvents, this review highlights some of the unique properties of deep eutectic solvents and deep-eutectic-solvent-based materials, as well as their applications in extraction and separation. In this paper, the available data and references in this field are reviewed to summarize the application developments of deep eutectic solvents. Based on the development of deep eutectic solvents, the exploitation of new deep eutectic solvents and deep-eutectic-solvent-based materials are expected to diversify into extraction and separation. PMID:25581398

  20. Salt Painting

    NSDL National Science Digital Library

    2012-06-26

    In this art meets chemistry activity, early learners discover the almost magical absorbent properties of salt while creating ethereal watercolor paintings. Learners first use watercolor to paint an image. Then, they sprinkle salt on the wet paint and observe. Use the provided discussion questions to encourage reflection.

  1. Directionally solidified eutectic gamma-gamma nickel-base superalloys

    NASA Technical Reports Server (NTRS)

    Jackson, M. R. (inventor)

    1977-01-01

    A directionally solidified multivariant eutectic gamma-gamma prime nickel-base superalloy casting having improved high temperature properties was developed. The alloy is comprised of a two phase eutectic structure consisting essentially of on a weight percent base, 6.0 to 9.0 aluminum, 5.0 to 17.0 tantalum, 0-10 cobalt, 0-6 vanadium, 0-6 rhenium, 2.0-6.0 tungsten, and the balance being nickel, subject to the proviso that the sum of the atomic percentages of aluminum plus tantalum is within the range of from 19-22, and the ratio of atomic percentages of tantalum to aluminum plus tantalum is within the range of from 0.12 to 0.23. Embedded within the gamma nickel-base matrix are aligned eutectic gamma prime phase (primarily nickel-aluminum-tantalum) reinforcing fibers.

  2. Recent advances in the molten salt destruction of energetic materials

    SciTech Connect

    Pruneda, C. O., LLNL

    1996-09-01

    We have demonstrated the use of the Molten Salt Destruction (MSD) Process for destroying explosives, liquid gun propellant, and explosives-contaminated materials on a 1.5 kg of explosive/hr bench- scale unit (1, 2, 3, 4, 5). In our recently constructed 5 kg/hr pilot- scale unit we have also demonstrated the destruction of a liquid gun propellant and simulated wastes containing HMX (octogen). MSD converts the organic constituents of the waste into non-hazardous substances such as carbon dioxide, nitrogen, and water. Any inorganic constituents of the waste, such as metallic particles, are retained in the molten salt. The destruction of energetic materials waste is accomplished by introducing it, together with air, into a vessel containing molten salt (a eutectic mixture of sodium, potassium, and lithium carbonates). The following pure explosives have been destroyed in our bench-scale experimental unit located at Lawrence Livermore National Laboratory`s (LLNL) High Explosives Applications Facility (HEAF): ammonium picrate, HMX, K- 6 (keto-RDX), NQ, NTO, PETN, RDX, TATB, and TNT. In addition, the following compositions were also destroyed: Comp B, LX- IO, LX- 1 6, LX- 17, PBX-9404, and XM46 (liquid gun propellant). In this 1.5 kg/hr bench-scale unit, the fractions of carbon converted to CO and of chemically bound nitrogen converted to NO{sub x} were found to be well below 1%. In addition to destroying explosive powders and compositions we have also destroyed materials that are typical of residues which result from explosives operations. These include shavings from machined pressed parts of plastic-bonded explosives and sump waste containing both explosives and non-explosive debris. Based on the process data obtained on the bench-scale unit we designed and constructed a next-generation 5 kg/hr pilot-scale unit, incorporating LLNL`s advanced chimney design. The pilot unit has completed process implementation operations and explosives safety reviews. To date, in this pilot unit we have successfully destroyed liquid gun propellant and dimethylsulfoxide containing HMX in continuous, long-duration runs.

  3. Refinement of eutectic silicon phase of aluminum A356 alloy using high-intensity ultrasonic vibration

    Microsoft Academic Search

    Xiaogang Jian; T. T. Meek; Q. Han

    2006-01-01

    The eutectic silicon in A356 alloy can be refined and modified using either chemical, quench, or superheating modification. We observed, for the first time, that the eutectic silicon can also be significantly refined using high-intensity ultrasonic vibration. Rosette-like eutectic silicon is formed during solidification of specimen treated with high-intensity ultrasonic vibration.

  4. Refinement of Eutectic Silicon Phase of Aluminum A356 Alloy Using High-Intensity Ultrasonic Vibration

    SciTech Connect

    Jian, Xiaogang [ORNL; Han, Qingyou [ORNL

    2006-01-01

    The eutectic silicon in A356 alloy can be refined and modified using either chemical, quench, or superheating modification. We observed, for the first time, that the eutectic silicon can also be significantly refined using high-intensity ultrasonic vibration. Rosette-like eutectic silicon is formed during solidification of specimen treated with high-intensity ultrasonic vibration.

  5. How polar are choline chloride-based deep eutectic solvents?

    PubMed

    Pandey, Ashish; Rai, Rewa; Pal, Mahi; Pandey, Siddharth

    2014-01-28

    Developing and characterizing green solvents with low toxicity and cost is one of the most important issues in chemistry. Deep Eutectic Solvents (DESs), in this regard, have shown tremendous promise. Compared to popular organic solvents, DESs possess negligible VOCs and are non-flammable. Compared to ionic liquids, which share many characteristics but are ionic compounds and not ionic mixtures, DESs are cheaper to make, much less toxic and mostly biodegradable. An estimate of the polarity associated with DESs is essential if they are to be used as green alternatives to common organic solvents in industries and academia. As no one physical parameter can satisfactorily represent solute-solvent interactions within a medium, polarity of DESs is assessed through solvatochromic optical spectroscopic responses of several UV-vis absorbance and molecular fluorescence probes. Information on the local microenvironment (i.e., the cybotactic region) that surrounds several solvatochromic probes [betaine dye, pyrene, pyrene-1-carboxaldehyde, 1-anilino-8-naphthalene sulfonate (ANS), p-toluidinyl-6-naphthalene sulfonate (TNS), 6-propionyl-2-(dimethylaminonaphthalene) (PRODAN), coumarin-153, and Nile Red] for four common and popular DESs formed from choline chloride combined with 1,2-ethanediol, glycerol, urea, and malonic acid, respectively, in 1?:?2 molar ratios termed ethaline, glyceline, reline, and maline is obtained and used to assess the effective polarity afforded by each of these DESs. The four DESs as indicated by these probe responses are found to be fairly dipolar in nature. Absorbance probe betaine dye and fluorescence probes ANS, TNS, PRODAN, coumarin-153, and Nile Red, whose solvatochromic responses are based on photoinduced charge-transfer, imply ethaline and glyceline, DESs formed using alcohol-based H-bond donors, to be relatively more dipolar in nature as compared to reline and maline. The pyrene polarity scale, which is based on polarity-induced changes in vibronic bands, indicates reline, the DES composed of urea as the hydrogen bond donor, to be significantly more dipolar than the other three DESs. Response of pyrene-1-carboxaldehyde, a polarity probe based on inversion of n-?* and ?-?* states, hints at maline to be the most dipolar of the four DESs. The molecular structure of the H-bond donor in a DES clearly controls the dipolarity afforded by the DES. H-bonding and other specific solute-solvent interactions are found to play an important role in solvatochromic probe behavior for the four DESs. The cybotactic region of a probe dissolved in a DES affords information on the polarity of the DES towards solutes of similar nature and functionality. PMID:24305780

  6. Prebiotic phosphate ester syntheses in a deep eutectic solvent.

    PubMed

    Gull, Maheen; Zhou, Manshui; Fernández, Facundo M; Pasek, Matthew A

    2014-02-01

    We report a route to synthesize a wide range of organophosphates of biological significance in a deep eutectic solvent (2:1 urea and choline chloride), utilizing various orthophosphate sources. Heating an organic alcohol in the solvent along with a soluble phosphorus source yields phosphorus esters of choline as well as that of the added organic in yields between 15 to 99 %. In addition, phosphite analogs of biological phosphates and peptides were also formed by the simple mixing of reagents and heating at 60-70 °C in the deep eutectic solvent. The presented dehydration reactions are relevant to prebiotic and green chemistry in alternative solvents. PMID:24368625

  7. Lead-bismuth eutectic technology for Hyperion reactor

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Kapernick, R. J.; McClure, P. R.; Trapp, T. J.

    2013-10-01

    A small lead-bismuth eutectic-cooled reactor concept (referred to as the Hyperion reactor concept) is being studied at Los Alamos National Laboratory and Hyperion Power Generation. In this report, a critical assessment of the lead-bismuth eutectic technology for Hyperion reactor is presented based on currently available knowledge. Included are: material compatibility, oxygen control, thermal hydraulics, polonium control. The key advances in the technology and their applications to Hyperion reactor design are analyzed. Also, the near future studies in main areas of the technology are recommended for meeting the design requirements.

  8. Theoretical study on the structures and properties of mixtures of urea and choline chloride.

    PubMed

    Sun, Hui; Li, Yan; Wu, Xue; Li, Guohui

    2013-06-01

    In this work, we investigated in detail the structural characteristics of mixtures of choline chloride and urea with different urea contents by performing molecular dynamic (MD) simulations, and offer possible explanations for the low melting point of the eutectic mixture of choline chloride and urea with a ratio of 1:2. The insertion of urea molecules was found to change the density distribution of cations and anions around the given cations significantly, disrupting the long-range ordered structure of choline chloride. Moreover, with increasing urea concentration, the hydrogen bond interactions between choline cations and Cl(-) anions decreased, while those among urea molecules obviously increased. From the hydrogen bond lifetimes, it was found that a ratio of 1:2 between choline chloride and urea is necessary for a reasonable strength of hydrogen bond interaction to maintain the low melting point of the mixture of choline chloride with urea. In addition, it was also deduced from the interaction energies that a urea content of 67.7 % may make the interactions of cation-anion, cation-urea and anion-urea modest, and thus results in the lower melting point of the eutectic mixture of choline chloride and urea. The present results may offer assistance to some extent for understanding the physicochemical properties of the eutectic mixture of choline chloride and urea, and give valuable information for the further development and application of deep eutectic solvents. PMID:23435478

  9. Molten salt destruction of energetic waste materials

    DOEpatents

    Brummond, William A. (Livermore, CA); Upadhye, Ravindra S. (Pleasanton, CA); Pruneda, Cesar O. (Livermore, CA)

    1995-01-01

    A molten salt destruction process is used to treat and destroy energetic waste materials such as high explosives, propellants, and rocket fuels. The energetic material is pre-blended with a solid or fluid diluent in safe proportions to form a fluid fuel mixture. The fuel mixture is rapidly introduced into a high temperature molten salt bath. A stream of molten salt is removed from the vessel and may be recycled as diluent. Additionally, the molten salt stream may be pumped from the reactor, circulated outside the reactor for further processing, and delivered back into the reactor or cooled and circulated to the feed delivery system to further dilute the fuel mixture entering the reactor.

  10. Structure of directionally solidified InSb-Sb eutectic alloy

    SciTech Connect

    Umehara, Y.; Koda, S.

    1987-11-01

    The eutectic alloy of InSb-Sb has been directionally solidified at various rates in order to investigate the structure changes due to solidification conditions. The boundary energy between the InSb and Sb phases was determined from a dislocation model of the interface.

  11. Eutectic epsilon-near-zero metamaterial terahertz waveguides

    E-print Network

    . Tzortzakis1,3, * 1 Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology that subwavelength waveguiding of terahertz radiation is achieved within an alkali­halide eutectic metamaterial or crystals [12]. Recently it has been shown that alkali­halide polari- tonic materials can be structured

  12. Eutectic alloys. Citations from the International Aerospace Abstracts data base

    NASA Technical Reports Server (NTRS)

    Moore, P.

    1980-01-01

    These 250 abstracts from the international literature provide summaries of the preparation, treatments, composition and structure, and properties of eutectic alloys. Techniques for directional solidification and treatments including glazing, coating, and fiber reinforcement are discussed. In addition to the mechanical and thermal properties, the superconducting, corrosion, resistance, and thermionic emission and adsorption properties are described.

  13. Microstructural evolution of eutectic Au-Sn solder joints

    SciTech Connect

    Song, Ho Geon

    2002-05-31

    Current trends toward miniaturization and the use of lead(Pb)-free solder in electronic packaging present new problems in the reliability of solder joints. This study was performed in order to understand the microstructure and microstructural evolution of small volumes of nominally eutectic Au-Sn solder joints (80Au-20Sn by weight), which gives insight into properties and reliability.

  14. Lamellar eutectic growth at large thermal gradient: I. Stationary patterns

    E-print Network

    Paris-Sud XI, Université de

    'inclinaison ». Abstract. 2014 We study stationary front profiles of directionally solidified lamellar eutectics. We show, Classification Physics Abstracts 61.50C - 64.60 - 64.70D - 81.30F 1. Introduction. Directional solidification rod patterns parallel to the common (Oz) direction of the pulling velocity V and of the external

  15. Plastic and Anelastic Responses of Ice-I/Magnesium Sulfate Hydrate Eutectic Aggregates

    NASA Astrophysics Data System (ADS)

    McCarthy, C.; Cooper, R. F.; Goldsby, D. L.; Kirby, S. H.; Durham, W. B.

    2006-12-01

    The presence of non-ice material (e.g. salt-hydrate) on the surface of icy satellites requires that we consider the influence of a second phase on the mechanical properties of ice. We are investigating experimentally the flow-strength and relaxation response (attenuation) of two-phase aggregates of magnesium sulfate hydrate and ice-I through compression creep tests (T = 240-250K; ? = 0.9-9.0 MPa) in a 1-atm, dead-weight, deformation apparatus modified for cryogenic use. All samples in our study crystallize from a homogeneous liquid solution that produces a classical eutectic microstructure. A misting and hot-pressing technique allows us to control grain size, or more accurately, colony size, in the samples. The steady-state (secondary) creep response of the ice/hydrate aggregate reveals that it has a viscosity that is at least an order of magnitude greater than that of pure polycrystalline ice at the same stress and temperature in what appears to be a dislocation creep regime. Since heterophase boundaries are found to be an effective barrier to dislocation motion, we attribute the increase in strength to the high volume of incoherent interfaces that the eutectic microstructure provides. We are also examining the transient (primary) creep in the strain response; this relaxation is an indication of the dissipative quality of the material from which we may begin to understand how mechanical energy (such as that from tidal loading) could be absorbed (dissipated) in the crust as heat. Information gleaned from these experiments can help constrain models of crustal thickness and surface dynamics on Europa.

  16. Use of Microgravity to Control the Microstructure of Eutectics

    NASA Technical Reports Server (NTRS)

    Wilcox, William R.; Regel, Liya L.; Smith, Reginald W.

    1998-01-01

    This grant began in June of 1996. Its long term goal is to be able to control the microstructure of directionally solidified eutectic alloys, through an improved understanding of the influence of convection. The primary objective of the present projects is to test hypotheses for the reported influence of microgravity on the microstructure of three fibrous eutectics (MnBi-Bi, InSb-NiSb, Al3Ni-Al). A secondary objective is to determine the influence of convection on the microstructure of other eutectic alloys. Two doctoral students and a masters student supported as a teaching assistant were recruited for this research. Techniques were developed for directional solidification of MnBi-Bi eutectics with periodic application of current pulses to produce an oscillatory freezing rate. Image analysis techniques were developed to obtain the variation in MnBi fiber spacing, which was found to be normally distributed. The mean and standard deviation of fiber spacing were obtained for several freezing conditions. Eighteen ampoules were prepared for use in the gradient freeze furnace QUELD developed at Queen's University for use in microgravity. Nine of these ampoules will be solidified soon at Queen's in a ground-based model. We hope to solidify the other nine in the QUELD that is mounted on the Canadian Microgravity Isolation Mount on MIR. Techniques are being developed for directional solidification of the Al-Si eutectic at different freezing rates, with and without application of accelerated crucible rotation to induce convection. For the first time, theoretical methods are being developed to analyze eutectic solidification with an oscillatory freezing rate. In a classical sharp-interface model, we found that an oscillatory freezing rate increases the deviation of the average interfacial composition from the eutectic, and increases the undercooling of the two phases by different amounts. This would be expected to change the volume fraction solidifying and the fiber spacing. Because of difficulties in tracking the freezing interfaces of the two solid phases, a phase-field model is also being developed. A paper demonstrating application of phase field methods to periodic structures has been submitted for publication.

  17. Thermophysical properties of reconsolidating crushed salt.

    SciTech Connect

    Bauer, Stephen J.; Urquhart, Alexander

    2014-03-01

    Reconsolidated crushed salt is being considered as a backfilling material placed upon nuclear waste within a salt repository environment. In-depth knowledge of thermal and mechanical properties of the crushed salt as it reconsolidates is critical to thermal/mechanical modeling of the reconsolidation process. An experimental study was completed to quantitatively evaluate the thermal conductivity of reconsolidated crushed salt as a function of porosity and temperature. The crushed salt for this study came from the Waste Isolation Pilot Plant (WIPP). In this work the thermal conductivity of crushed salt with porosity ranging from 1% to 40% was determined from room temperature up to 300oC, using two different experimental methods. Thermal properties (including thermal conductivity, thermal diffusivity and specific heat) of single-crystal salt were determined for the same temperature range. The salt was observed to dewater during heating; weight loss from the dewatering was quantified. The thermal conductivity of reconsolidated crushed salt decreases with increasing porosity; conversely, thermal conductivity increases as the salt consolidates. The thermal conductivity of reconsolidated crushed salt for a given porosity decreases with increasing temperature. A simple mixture theory model is presented to predict and compare to the data developed in this study.

  18. Examination of Liquid Fluoride Salt Heat Transfer

    SciTech Connect

    Yoder Jr, Graydon L [ORNL] [ORNL

    2014-01-01

    The need for high efficiency power conversion and energy transport systems is increasing as world energy use continues to increase, petroleum supplies decrease, and global warming concerns become more prevalent. There are few heat transport fluids capable of operating above about 600oC that do not require operation at extremely high pressures. Liquid fluoride salts are an exception to that limitation. Fluoride salts have very high boiling points, can operate at high temperatures and low pressures and have very good heat transfer properties. They have been proposed as coolants for next generation fission reactor systems, as coolants for fusion reactor blankets, and as thermal storage media for solar power systems. In each case, these salts are used to either extract or deliver heat through heat exchange equipment, and in order to design this equipment, liquid salt heat transfer must be predicted. This paper discusses the heat transfer characteristics of liquid fluoride salts. Historically, heat transfer in fluoride salts has been assumed to be consistent with that of conventional fluids (air, water, etc.), and correlations used for predicting heat transfer performance of all fluoride salts have been the same or similar to those used for water conventional fluids an, water, etc). A review of existing liquid salt heat transfer data is presented, summarized, and evaluated on a consistent basis. Less than 10 experimental data sets have been found in the literature, with varying degrees of experimental detail and measured parameters provided. The data has been digitized and a limited database has been assembled and compared to existing heat transfer correlations. Results vary as well, with some data sets following traditional correlations; in others the comparisons are less conclusive. This is especially the case for less common salt/materials combinations, and suggests that additional heat transfer data may be needed when using specific salt eutectics in heat transfer equipment designs. All of the data discussed above were taken under forced convective conditions (both laminar and turbulent). Some recent data taken at ORNL under free convection conditions are also presented and results discussed. This data was taken using a simple crucible experiment with an instrumented nickel heater inserted in the salt to induce natural circulation within the crucible. The data was taken over a temperature range of 550oC to 650oC in FLiNaK salt. This data covers both laminar and turbulent natural convection conditions, and is compared to existing forms of natural circulation correlations.

  19. Salt Tolerance of Desorption Electrospray Ionization (DESI)

    SciTech Connect

    Jackson, Ayanna U. [Purdue University; Talaty, Nari [Purdue University; Cooks, R G [Purdue University; Van Berkel, Gary J [ORNL

    2007-01-01

    Suppression of ion intensity in the presence of high salt matrices is common in most mass spectrometry ionization techniques. Desorption electrospray ionization (DESI) is an ionization method that exhibits salt tolerance, and this is investigated. DESI analysis was performed on three different drug mixtures in the presence of 0, 0.2, 2, 5, 10, and 20% NaCl:KCl weight by volume from seven different surfaces. At physiological concentrations individual drugs in each mixture were observed with each surface. Collision-induced dissociation (CID) was used to provide additional confirmation for select compounds. Multiple stage experiments, to MS5, were performed for select compounds. Even in the absence of added salt, the benzodiazepine containing mixture yielded sodium and potassium adducts of carbamazepine which masked the ions of interest. These adducts were eliminated by adding 0.1% 7M ammonium acetate to the standard methanol:water (1:1) spray solvent. Comparison of the salt tolerance of DESI with that of electrospray ionization (ESI) demonstrated much better signal/noise characteristics for DESI in this study. The salt tolerance of DESI was also studied by performing limit of detection and dynamic range experiments. Even at a salt concentration significantly above physiological concentrations, select surfaces were effective in providing spectra that allowed the ready identification of the compounds of interest. The already high salt tolerance of DESI can be optimized further by appropriate choices of surface and spray solution.

  20. Hydride-containing molten salts and their technology implications

    NASA Astrophysics Data System (ADS)

    Liaw, Bor Y.

    1993-03-01

    Hydride-conducting molten salts such as LiH in eutectic LiCl-KCl are attractive electrolyte systems for intermediate-temperature applications. The chemically reducing characteristics of these hydride melts provide a unique method to clean metal surfaces. The high conductivity of these hydride melts makes them the best electrolytes for hydrogen-based energy applications at intermediate temperatures. We will review some earlier work on hydride-conducting molten salts and their potential applications in energy technology. We will also describe some recent work on these hydride-containing molten salts for energy conversion and storage applications, including hydrogen sensing and hydrogen storage, electrochemical characterizations, and thermodynamic and kinetic investigations of metal-hydrogen reactions. More recently, lithium deuteride containing eutectic LiCl-KCl melts have been used for excess heat production by the process of electrolysis to charge deuterium into metal matrix such as Pd and Ti. From these studies we illustrate the prospects of this hydride molten salt technology and its implications for the use in intermediate-temperature electro-chemical energy conversion configurations. It will also reveal some interesting electrochemical aspects involved in the processes.

  1. Choline chloride-thiourea, a deep eutectic solvent for the production of chitin nanofibers.

    PubMed

    Mukesh, Chandrakant; Mondal, Dibyendu; Sharma, Mukesh; Prasad, Kamalesh

    2014-03-15

    Deep eutectic solvents (DESs) consisting of the mixtures of choline halide (chloride/bromide)-urea and choline chloride-thiourea were used as solvents to prepare ?-chitin nanofibers (CNFs). CNFs of diameter 20-30 nm could be obtained using the DESs comprising of the mixture of choline chloride and thiourea (CCT 1:2); however, NFs could not be obtained using the DESs having urea (CCU 1:2) as hydrogen bond donor. The physicochemical properties of thus obtained NFs were compared with those obtained using a couple of imidazolium based ionic liquids namely, 1-butyl-3-methylimidazolium hydrogen sulphate [(Bmim)HSO4] and 1-methylimidazolium hydrogen sulphate [(Hmim)HSO4] as well as choline based bio-ILs namely, choline hydrogen sulphate [(Chol)HSO4] and choline acrylate. The CNFs obtained using the DES as a solvent were used to prepare calcium alginate bio-nanocomposite gel beads having enhanced elasticity in comparison to Ca-alginate beads. The bio-nanocomposite gel beads thus obtained were used to study slow release of 5-fluorouracil, an anticancer drug. PMID:24528755

  2. Fluoride salts as phase change materials for thermal energy storage in the temperature range 1000-1400 K

    NASA Technical Reports Server (NTRS)

    Misra, Ajay K.

    1988-01-01

    Eutectic compositions and congruently melting intermediate compounds in binary and ternary fluoride salt systems were characterized for potential use as latent heat of fusion phase change materials to store thermal energy in the temperature range 1000-1400 K. The melting points and eutectic compositions for many systems with published phase diagrams were experimentally verified and new eutectic compositions having melting points between 1000 and 1400 K were identified. Heats of fusion of several binary and ternary eutectics and congruently melting compounds were experimentally measured by differential scanning calorimetry. For a few systems in which heats of mixing in the melts have been measured, heats of fusion of the eutectics were calculated from thermodynamic considerations and good agreement was obtained between the measured and calculated values. Several combinations of salts with high heats of fusion per unit mass (greater than 0.7 kJ/g) have been identified for possible use as phase change materials in advanced solar dynamic space power applications.

  3. Brines formed by multi-salt deliquescence

    SciTech Connect

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

    2005-11-04

    The FY05 Waste Package Environment testing program at Lawrence Livermore National Laboratory focused on determining the temperature, relative humidity, and solution compositions of brines formed due to the deliquescence of NaCl-KNO{sub 3}-NaNO{sub 3} and NaCl-KNO{sub 3}-NaNO{sub 3}-Ca(NO{sub 3}){sub 2} salt mixtures. Understanding the physical and chemical behavior of these brines is important because they define conditions under which brines may react with waste canister surfaces. Boiling point experiments show that NaCl-KNO{sub 3}-NaNO{sub 3} and NaCl-KNO{sub 3}-NaNO{sub 3}-Ca(NO{sub 3}){sub 2} salt mixtures form brines that transform to hydrous melts that do not truly 'dry out' until temperatures exceed 300 and 400 C, respectively. Thus a conducting solution is present for these salt assemblages over the thermal history of the repository. The corresponding brines form at lower relative humidity at higher temperatures. The NaCl-KNO{sub 3}-NaNO{sub 3} salt mixture has a mutual deliquescence relative humidity (MDRH) of 25.9% at 120 C and 10.8% at 180 C. Similarly, the KNO{sub 3}-NaNO{sub 3} salt mixture has MDRH of 26.4% at 120 C and 20.0% at 150 C. The KNO{sub 3}-NaNO{sub 3} salt mixture salts also absorb some water (but do not appear to deliquesce) at 180 C and thus may also contribute to the transfer of electrons at interface between dust and the waste package surface. There is no experimental evidence to suggest that these brines will degas and form less deliquescent salt assemblages. Ammonium present in atmospheric and tunnel dust (as the chloride, nitrate, or sulfate) will readily decompose in the initial heating phase of the repository, and will affect subsequent behavior of the remaining salt mixture only through the removal of a stoichiometric equivalent of one or more anions. Although K-Na-NO{sub 3}-Cl brines form at high temperature and low relative humidity, these brines are dominated by nitrate, which is known to inhibit corrosion at lower temperature. Nitrate to chloride ratios of the NaCl-KNO{sub 3}-NaNO{sub 3} salt mixture are about NO{sub 3}:Cl = 19:1. The role of nitrate on corrosion at higher temperatures is addressed in a companion report (Dixit et al., 2005).

  4. Salt Marsh

    NSDL National Science Digital Library

    High school level and higher description of Spartina salt marshes with pictures. Page is full of fantastic photographs most featuring a descriptive caption. Topics discussed include zonation, succession, and the intertidal zone. The habitat's associated flora and fauna are discussed. Organisms of particular interest include: Spartina alterniflora, Spartina patens, Geukenzia demissa, Mytilus edulis, Distichlis spicata, Salicornia, Melampus bidentatus, Ilyanassa obsoleta, and Hydrobia totteni.

  5. Chlorate salts and solutions on Mars

    NASA Astrophysics Data System (ADS)

    Hanley, Jennifer; Chevrier, Vincent F.; Berget, Deanna J.; Adams, Robert D.

    2012-04-01

    Chlorate (ClO3-) is an intermediate oxidation species between chloride (Cl-) and perchlorate (ClO4-), both of which were found at the landing site by the Wet Chemistry Lab (WCL). The chlorate ion is almost as stable as perchlorate, and appears to be associated with perchlorate in most terrestrial reservoirs (e.g. Atacama and Antarctica). It is possible that chlorate contributed to the ion sensor response on the WCL, yet was masked by the strong perchlorate signal. However, very little is known about chlorate salts and their effect on the stability of water. We performed evaporation rate experiments in our Mars simulation chamber, which enabled us to determine the activity of water for various concentrations. From this we constructed solubility diagrams for NaClO3, KClO3, Mg(ClO3)2 and Ca(ClO3)2, and determined the Pitzer parameters for each salt. Chlorate salt eutectic temperatures range from 270 K (KClO3) to 204 K (Mg(ClO3)2). Modeling the addition of chlorate to the initial WCL solutions shows that it precipitates in concentrations comparable to other common salts, such as gypsum and epsomite, and implies that chlorates may play an important role in the wet chemistry on Mars.

  6. Eutectic bonding of boron-aluminum structural components. II

    NASA Technical Reports Server (NTRS)

    Niemann, J. T.; Garrett, R. A.

    1974-01-01

    Eutectic bonding is a diffusion brazing process developed for fabricating boron-aluminum components from composite monolayer. This process relies on the diffusion of a thin surface film of copper into the aluminum matrix to form a liquid phase when heated above the copper-aluminum eutectic temperature of 1018 F. This type of fabrication offers design flexibility in that skin thickness may be varied, the stiffness geometry and orientation can be varied, and local reinforcement can be added. In addition, this type of boron-aluminum structure offers high efficiency. Also, this method of construction can be cost-comparative with complex titanium shapes; simple tooling permits easy layup, bonding is a one-step operation, and little finish machining is required.

  7. Corrosion of ODS steels in lead bismuth eutectic

    NASA Astrophysics Data System (ADS)

    Hosemann, P.; Thau, H. T.; Johnson, A. L.; Maloy, S. A.; Li, N.

    2008-02-01

    Oxide dispersion strengthened (ODS) ferritic steels are advanced materials being developed for high temperature applications. Their properties (high temperature strength, creep resistance, corrosion/oxidation resistance) make them potentially usable for high temperature applications in liquid metal cooled systems like liquid lead-bismuth eutectic cooled reactors and spallation sources. Corrosion tests on five different ODS alloys were performed in flowing liquid lead-bismuth eutectic in the DELTA Loop at the Los Alamos National Laboratory at 535 °C for 200 h and 600 h. The tested materials were chromium alloyed ferritic/martensitic steels (12YWT, 14YWT, MA957) and Cr-Al alloyed steels (PM2000, MA956). It was shown that the Al alloyed ODS steel above 5.5 wt% Al (PM2000) is highly resistant to corrosion and oxidation in the conditions examined, and that the corrosion properties of the ODS steels depend strongly on their grain size.

  8. Glucose-based deep eutectic solvents: Physical properties

    Microsoft Academic Search

    A. Hayyan; F. S. Mjalli; I. M. Alnashef; Y. M. Al-Wahaibi; T. Al-Wahaibi; M. A. Hashim

    2013-01-01

    Deep eutectic solvents (DESs) are considered nowadays as green ionic liquid (IL) analogues. Despite their relatively short period of introduction as a special class of ILs, they have been under an increasing emphasis by the scientific community due to their favorable properties. In the present study, a glucose based DES of choline chloride (2-hydroxyethyl-trimethylammonium chloride) with the monosaccharide sugar d-glucose

  9. Creep of directionally solidified alumina\\/YAG eutectic monofilaments

    Microsoft Academic Search

    L. E. Matson; N. Hecht

    2005-01-01

    Multi-phase—single crystal oxide fibers offer the best choice for reinforcing oxide matrix composites because they have superior creep resistance up to 1700°C without significant strength loss at moderate temperatures due to growth of processing flaws. In this work, Directionally Solidified Al2O3–YAG eutectic fibers were grown at various rates by the Edge-defined, Film-fed Growth (EFG) method and their microstructure, microstructural stability

  10. Unidirectional solidification of Co-Cr-C monovariant eutectic alloys

    Microsoft Academic Search

    E. R. Thompson; F. D. Lemkey

    1970-01-01

    Compositions on the eutectic liquidus line between Co-25 wt pct Cr-3.5 wt pct C and Co-45 wt pct Cr-2.2 wt pct C wherein the simultaneous freezing of a metal matrix and a carbide occur have been solidified unidirectionally. The composite structures formed consist of a cobalt matrix containing substantial amounts of soluble chromium with the carbide phase, (Cr, Co)7C3, as

  11. Magnetic properties of directionally solidified MnBi-Bi eutectics

    Microsoft Academic Search

    C. Graham; M. Notis; J.-C. Boulbes

    1972-01-01

    Samples consisting of approximately parallel arrays of ferromagnetic MnBi rods in a Bi matrix have been grown by directional solidification of eutectic Mn-Bi alloys. The rods are of order 1?m in diameter, and very long in comparison to their diameter. Room-temperature intrinsic coercive fields up to 30 kOe have been attained, suggesting that the rods show single-domain behavior. The measured

  12. An approximate formula for recalescence in binary eutectic alloys

    NASA Technical Reports Server (NTRS)

    Ohsaka, K.; Trinh, E. H.

    1993-01-01

    In alloys, solidification takes place along various paths which may be ascertained via phase diagrams; while there would be no single formula applicable to all alloys, an approximate formula for a specific solidification path would be useful in estimating the fraction of the solid formed during recalescence. A formulation is here presented of recalescence in binary eutectic alloys. This formula is applied to Ag-Cu alloys which are of interest in containerless solidification, due to their formation of supersaturated solutions.

  13. Fatigue crack propagation behaviour of unidirectionally solidified ?\\/??-? eutectic alloys

    Microsoft Academic Search

    Philip E. Bretz; Richard W. Hertzberg

    1979-01-01

    Fatigue crack propagation (FCP) studies were conducted on a series of?\\/??-? (Ni-Nb-Al) alloys by subjecting them to cyclic four-point bending loads at room temperature. The aluminium contents of the alloys investigated ranged from 1.5% to 2.5% by weight, with the niobium contents adjusted to maintain controlled eutectic microstructures. In addition to studies of as-grown alloys, heat treatments were performed on

  14. ?SR studies of superconductivity in eutectically grown mixed ruthenates

    NASA Astrophysics Data System (ADS)

    Shiroka, T.; Fittipaldi, R.; Cuoco, M.; De Renzi, R.; Maeno, Y.; Lycett, R. J.; Ramos, S.; Forgan, E. M.; Baines, C.; Rost, A.; Granata, V.; Vecchione, A.

    2012-04-01

    The low-temperature magnetic behavior of the double-layered ruthenate Sr3Ru2O7, as grown from a eutectic Sr2RuO4-Sr3Ru2O7 system, was investigated via zero- and transverse-field muon-spin rotation. The gradual increase of the muon relaxation rate observed below 2.5 K, even in the absence of applied magnetic fields, indicates the occurrence of a spontaneous breaking of time-reversal symmetry. The onset of the latter at a temperature above 1.5 K, the Tc of the single phase Sr2RuO4, provides evidence about an unconventional superconducting state in the eutectic phase, which most likely takes place at the interface between the Sr2RuO4 and Sr3Ru2O7 domains, or even inside the Sr3Ru2O7 phase. We show that the superconducting state manifests a two-component behavior in the transverse-field response with change-over at about T=2.5 K and T=1.5 K. The comparison with zero-field ?SR data in the Ru-Sr2RuO4 eutectic system rules out the possibility of spurious effects due to embedded Ru islands.

  15. Protein aggregation in salt solutions.

    PubMed

    Kastelic, Miha; Kalyuzhnyi, Yurij V; Hribar-Lee, Barbara; Dill, Ken A; Vlachy, Vojko

    2015-05-26

    Protein aggregation is broadly important in diseases and in formulations of biological drugs. Here, we develop a theoretical model for reversible protein-protein aggregation in salt solutions. We treat proteins as hard spheres having square-well-energy binding sites, using Wertheim's thermodynamic perturbation theory. The necessary condition required for such modeling to be realistic is that proteins in solution during the experiment remain in their compact form. Within this limitation our model gives accurate liquid-liquid coexistence curves for lysozyme and [Formula: see text] IIIa-crystallin solutions in respective buffers. It provides good fits to the cloud-point curves of lysozyme in buffer-salt mixtures as a function of the type and concentration of salt. It than predicts full coexistence curves, osmotic compressibilities, and second virial coefficients under such conditions. This treatment may also be relevant to protein crystallization. PMID:25964322

  16. Metastable Eutectic Equilibrium in Natural Environments: Recent Development and Research Opportunities

    NASA Technical Reports Server (NTRS)

    Rietmeijer, Frans J. M.; Nuth, Joseph A., III; Jablonska, Mariola; Karner, James M.

    2000-01-01

    Chemical ordering at metastable eutectics was recognized in non-equilibrium gas-to- solid condensation experiments to constrain 'silicate' dust formation in O-rich circumstellar environments. The predictable metastable eutectic behavior successfully predicted the observed ferromagnesiosilica compositions of circumstellar dust presolar and solar nebula grains in the matrix of the collected aggregate IDPs (Interplanetary Dust Particles). Many of the experimentally determined metastable eutectic solids match the fundamental building blocks of common rock-forming layer silicates: this could have implications for the origin of Life. The physical conditions conducive to metastable eutectic behavior, i.e. high temperature and (ultra) fast quenching, lead to unique amorphous, typically nano- to micrometer-sized, materials. The new paradigm of metastable eutectic behavior opens the door to new and exciting research opportunities in uncovering the many implications of these unique amorphous, and typically nano-to micrometer-sized, metastable eutectic materials.

  17. Metastable Eutectic Equilibrium in Natural Environments: Recent Developments and Research Opportunities

    NASA Technical Reports Server (NTRS)

    Rietmeijer, Fans J. M.; Nuth, Joseph A., II; Jablonska, Mariola; Karner, James M.

    2000-01-01

    Chemical ordering at metastable eutectics was recognized in non-equilibrium gas-to- solid condensation experiments to constrain 'silicate' dust formation in O-rich circumstellar environments. The predictable metastable eutectic behavior successfully predicted the observed ferromagnesiosilica, compositions of circumstellar dust, presolar and solar nebula grains in the matrix of the collected aggregate IDPs. Many of the experimentally determined metastable eutectic solids match the fundamental building blocks of common rock-forming layer silicates: this could have implications for the origin of Life. The physical conditions conducive to metastable eutectic behavior, i.e. high temperature and (ultra)fast quenching, lead to unique amorphous, typically nano- to micrometer-sized, materials. The new paradigm of metastable eutectic behavior opens the door to new and exciting research opportunities in uncovering the many implications of these unique amorphous and typically nano- to micrometer-sized, metastable eutectic materials.

  18. Modeling soluble salt assemblages on Mars: past aqueous history and present-day habitability

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    Soluble salt assemblages formed through aqueous processes are widespread on Mars. These minerals are important for understanding the past aqueous history of Mars and indicate critical habitability parameters such as pH, temperature, water activity, and salinity. Equilibrium models have been used to determine solution chemistry and salt precipitation sequences from aqueous chemical data; however, current models are limited by a lack of experimental data for low-temperature perchlorates, and some model predictions are clearly anomalous. To address the need for accurate equilibrium models, we have developed a comprehensive model for low-temperature perchlorate-rich brines using (1) previously neglected literature data, (2) experimental solubilities determined in low-temperature perchlorate solutions, and (3) solubility and heat capacity results determined using Differential Scanning Calorimetry (DSC). Our resulting model is a significant improvement over existing models, such as FREZCHEM, particularly for perchlorate mixtures. We have applied our model to evaporation and freezing of a nominal Wet Chemistry Laboratory (WCL) solution measured at the Phoenix site. For a freezing WCL solution, our model indicates that ice, KClO4, hydromagnesite (3MgCO3·Mg(OH)2·3H2O), calcite (CaCO3), meridianiite (MgSO4·11H2O), MgCl2·12H2O, NaClO4·2H2O, and Mg(ClO4)2·6H2O form at the eutectic (209 K); whereas, KClO4, hydromagnesite, kieserite (MgSO4·H2O), anhydrite (CaSO4), halite (NaCl), NaClO4·H2O, and Mg(ClO4)2·6H2O form upon complete evaporation at 298 K. In general, evaporation yields more dehydrated mineral assemblages than salts produced by freezing. Hydrated phases that form during evaporation contain 0.3 wt. % water, which compares with 1.2 wt. % during freezing. Given independent evidence for the presence of calcite and minimum water contents in Martian soils of ~1.5 wt. %, salts at the Phoenix site, and possibly elsewhere, appear more likely to have formed during freezing. Furthermore, our model indicates that some minerals, such as halite, kieserite, epsomite, and mirabilite (Na2SO4·10H2O) form only under limited temperature and water activity conditions, and could be used to constrain the past aqueous history of Mars.

  19. Studies of directionally solidified eutectic Bi\\/MnBi at low growth velocities

    Microsoft Academic Search

    Ron G. Pirich

    1984-01-01

    A deviation from the interrod spacing (?) and growth velocity (V) relation ?2V = constant, anticipated for diffusion-only rod eutectic growth, has been observed at growth velocities ?5 cm\\/h (14 µm\\/s)\\u000a in directionally solidified eutectic Bi-Mn (Bi\\/MnBi). At lower growth velocities,V? 0.5 cm\\/h, a breakdown in the aligned rod eutectic, cooperative growth mechanism, has also been noted. The ?2V relation

  20. A numerical model for eutectic spacing selection in the CBr 4?C 2Cl 6 eutectic system

    NASA Astrophysics Data System (ADS)

    Liu, Jincheng; Elliott, R.

    1995-03-01

    It is well established that the lamellar eutectic structure exhibits a limited range of spacings rather than a unique spacing during steady state growth at a constant growth velocity. The minimum observed spacing corresponds to the extremum spacing predicted by the Jackson and Hunt analysis of eutectic growth. However, the maximum observed spacing is much less than the maximum spacing predicted by their analysis. The assumption of a planar interface by Jackson and Hunt is relaxed in this paper and a numerical model is developed which uses the boundary element method and an iterative technique to obtain the solute distribution for a selfconsistent curved interface shape. The maximum selfconsistent spacing, for which a selfconsistent interface exists, is determined for several growth velocities. The maximum selfconsistent spacings calculated in this way show good agreement with the maximum spacings observed in the CBr 4?C 2Cl 6 eutectic system. The interface shape for the maximum selfconsistent spacings has a limiting slope which is far from vertical and the deepest point on the selfconsistent interface at the maximum spacing does not lie in a deep pocket.

  1. Micro-to-nano-scale deformation mechanisms of a bimodal ultrafine eutectic composite

    PubMed Central

    Lee, Seoung Wan; Kim, Jeong Tae; Hong, Sung Hwan; Park, Hae Jin; Park, Jun-Young; Lee, Nae Sung; Seo, Yongho; Suh, Jin Yoo; Eckert, Jürgen; Kim, Do Hyang; Park, Jin Man; Kim, Ki Buem

    2014-01-01

    The outstading mechanical properties of bimodal ultrafine eutectic composites (BUECs) containing length scale hierarchy in eutectic structure were demonstrated by using AFM observation of surface topography with quantitative height measurements and were interpreted in light of the details of the deformation mechanisms by three different interface modes. It is possible to develop a novel strain accommodated eutectic structure for triggering three different interface-controlled deformation modes; (I) rotational boundary mode, (II) accumulated interface mode and (III) individual interface mode. A strain accommodated microstructure characterized by the surface topology gives a hint to design a novel ultrafine eutectic alloys with excellent mechanical properties. PMID:25265897

  2. Stress production and relief in the gold/silicon eutectic die-attach process

    NASA Astrophysics Data System (ADS)

    Hund, T. D.; Burchett, S. N.

    1983-06-01

    Eutectic braze thickness and package cooling rate for stress relief in eutectically bonded die were evaluated. Two package types, a 30 pin leadless chip carrier and a 28 pin flat pack were used as models in finite element stress calculations to study these parameters on the maximum principal stress, maximum circumferential stress, and maximum shear stress. Bonding temperature, creep rate, silicon tensile strength, and the effects of surface defects on silicon tensile strength were studied to evaluate their effects on stresses in the die. It is indicated that with a thicker eutectic braze and a slower cooling rate, die can be eutectically attached without excessive stress.

  3. Micro-to-nano-scale deformation mechanisms of a bimodal ultrafine eutectic composite.

    PubMed

    Lee, Seoung Wan; Kim, Jeong Tae; Hong, Sung Hwan; Park, Hae Jin; Park, Jun-Young; Lee, Nae Sung; Seo, Yongho; Suh, Jin Yoo; Eckert, Jürgen; Kim, Do Hyang; Park, Jin Man; Kim, Ki Buem

    2014-01-01

    The outstading mechanical properties of bimodal ultrafine eutectic composites (BUECs) containing length scale hierarchy in eutectic structure were demonstrated by using AFM observation of surface topography with quantitative height measurements and were interpreted in light of the details of the deformation mechanisms by three different interface modes. It is possible to develop a novel strain accommodated eutectic structure for triggering three different interface-controlled deformation modes; (I) rotational boundary mode, (II) accumulated interface mode and (III) individual interface mode. A strain accommodated microstructure characterized by the surface topology gives a hint to design a novel ultrafine eutectic alloys with excellent mechanical properties. PMID:25265897

  4. Multicomponent diffusion in molten salt LiF-BeF2: Dynamical correlations and Maxwell-Stefan diffusivities

    NASA Astrophysics Data System (ADS)

    Chakraborty, Brahmananda; Ramaniah, Lavanya M.

    2015-06-01

    Applying Green-Kubo formalism and equilibrium molecular dynamics (MD) simulations, we have studied the dynamic correlation, Onsager coeeficients and Maxwell-Stefan (MS) Diffusivities of molten salt LiF-BeF2, which is used as coolant in high temperature reactor. All the diffusive flux correlations show back-scattering or cage dynamics which becomes pronouced at higher temperature. Although the MS diffusivities are expected to depend very lightly on the composition due to decoupling of thermodynamic factor, the diffusivity ?Li-F and ?Be-F decreases sharply for higher concentration of LiF and BeF2 respectively. Interestingly, all three MS diffusivities have highest magnitude for eutectic mixture at 1000K (except ?Be-F at lower LiF mole fraction) which is desirable from coolant point of view. Although the diffusivity for positive-positive ion pair is negative it is not in violation of the second law of thermodynamics as it satisfies the non-negative entropic constraints.

  5. A new technique for direct traceability of contact thermometry Co-C eutectic cells to the ITS-90

    SciTech Connect

    Failleau, G.; Deuzé, T.; Bourson, F.; Briaudeau, S.; Sadli, M. [Laboratoire Commun de Métrologie LNE-Cnam, 61 rue du Landy 93210 La Plaine Saint Denis (France)] [Laboratoire Commun de Métrologie LNE-Cnam, 61 rue du Landy 93210 La Plaine Saint Denis (France)

    2013-09-11

    The eutectic Co-C melting point is a promising system to serve as a thermometric fixed-point in the temperature range above 1084.62 °C (copper freezing point). During the last decade, LNE-Cnam has developed and characterized some fixed-point devices, based on eutectic Co-C alloy, for applications to contact and radiation thermometry. Above 962 °C, the ITS-90 is realized by radiation thermometry by the extrapolation from a Ag, Au or Cu fixed point using the Planck law for radiation. So the only way for assigning a temperature in the scale to a Co-C cell (?1324 °C) is by radiation thermometry. An indirect method is commonly used to assign a temperature to a high-temperature fixed point (HTFP) cell designed for contact thermometry is to fill a pyrometric cell with the same mixture as the contact thermometry cell. In this case, the temperature assigned to the pyrometric cell is attributed to the contact cell. This paper describes a direct method allowing the determination of the melting temperature realized by a 'contact thermometry' Co-C cell by comparison to a 'radiation thermometry' Co-C cell whose melting temperature was assigned in accordance to the scale by extrapolation from the Cu point. In addition, the same Co-C cell is studied with a standard Pt/Pd thermocouple.

  6. Electrochemical fabrication of nanoporous copper films in choline chloride-urea deep eutectic solvent.

    PubMed

    Zhang, Q B; Abbott, Andrew P; Yang, C

    2015-05-27

    Nanoporous copper films were fabricated by a facile electrochemical alloying/dealloying process without the need of a template. A deep eutectic solvent made from choline chloride (ChCl) and urea was used with zinc oxide as the metal salt. Cyclic voltammetry was used to characterise the electrochemical reduction of zinc and follow Cu-Zn alloy formation on the copper substrate at elevated temperatures from 353 to 393 K. The alloy formation was confirmed by X-ray diffraction spectra. 3D, open and bicontinuous nanoporous copper films were obtained by in situ electrochemically etching (dealloying) of the zinc component in the Cu-Zn surface alloys at an appropriate potential (-0.4 V vs. Ag). This dealloying process was found to be highly temperature dependent and surface diffusion controlled, which involved the self-assembly of copper atoms at the alloy/electrolyte interface. Additionally, the effects of the deposition parameters, including deposition temperature, current density as well as total charge density on resulting the microstructure were investigated by scanning electron microscopy, and atomic force microscope. PMID:25972227

  7. Prebiotic chemistry in eutectic solutions at the water-ice matrix.

    PubMed

    Menor-Salván, César; Marín-Yaseli, Margarita R

    2012-08-21

    A crystalline ice matrix at subzero temperatures can maintain a liquid phase where organic solutes and salts concentrate to form eutectic solutions. This concentration effect converts the confined reactant solutions in the ice matrix, sometimes making condensation and polymerisation reactions occur more favourably. These reactions occur at significantly high rates from a prebiotic chemistry standpoint, and the labile products can be protected from degradation. The experimental study of the synthesis of nitrogen heterocycles at the ice-water system showed the efficiency of this scenario and could explain the origin of nucleobases in the inner Solar System bodies, including meteorites and extra-terrestrial ices, and on the early Earth. The same conditions can also favour the condensation of monomers to form ribonucleic acid and peptides. Together with the synthesis of these monomers, the ice world (i.e., the chemical evolution in the range between the freezing point of water and the limit of stability of liquid brines, 273 to 210 K) is an under-explored experimental model in prebiotic chemistry. PMID:22660387

  8. Deep eutectic solvent-assisted synthesis of biodegradable polyesters with antibacterial properties.

    PubMed

    García-Argüelles, Sara; Serrano, M Concepción; Gutiérrez, María C; Ferrer, M Luisa; Yuste, Luis; Rojo, Fernando; del Monte, Francisco

    2013-07-30

    Bacterial infection related to the implantation of medical devices represents a serious clinical complication, with dramatic consequences for many patients. In past decades, numerous attempts have been made to develop materials with antibacterial and/or antifouling properties by the incorporation of antibiotic and/or antiseptic compounds. In this context, deep eutectic solvents (DESs) are acquiring increasing interest not only as efficient carriers of active principle ingredients (APIs) but also as assistant platforms for the synthesis of a wide repertoire of polymer-related materials. Herein, we have successfully prepared biodegradable poly(octanediol-co-citrate) polyesters with acquired antibacterial properties by the DES-assisted incorporation of quaternary ammonium or phosphonium salts into the polymer network. In the resulting polymers, the presence of these salts (i.e., choline chloride, tetraethylammonium bromide, hexadecyltrimethylammonium bromide, and methyltriphenylphosphonium bromide) inhibits bacterial growth in the early postimplantation steps, as tested in cultures of Escherichia coli on solid agar plates. Later, positive polymer cytocompatibility is expected to support cell colonization, as anticipated from in vitro preliminary studies with L929 fibroblasts. Finally, the attractive elastic properties of these polyesters permit matching those of soft tissues such as skin. For all of these reasons, we envisage the utility of some of these antibacterial, biocompatible, and biodegradable polyesters as potential candidates for the preparation of antimicrobial wound dressings. These results further emphasize the enormous versatility of DES-assisted synthesis for the incorporation, in the synthesis step, of a wide palette of APIs into polymeric networks suitable for biomedical applications. PMID:23808373

  9. How a protein can remain stable in a solvent with high content of urea: insights from molecular dynamics simulation of Candida antarctica lipase B in urea?:?choline chloride deep eutectic solvent.

    PubMed

    Monhemi, Hassan; Housaindokht, Mohammad Reza; Moosavi-Movahedi, Ali Akbar; Bozorgmehr, Mohammad Reza

    2014-07-28

    Deep eutectic solvents (DESs) are utilized as green and inexpensive alternatives to classical ionic liquids. It has been known that some of DESs can be used as solvent in the enzymatic reactions to obtain very green chemical processes. DESs are quite poorly understood at the molecular level. Moreover, we do not know much about the enzyme microstructure in such systems. For example, how some hydrolase can remain active and stable in a deep eutectic solvent including 9 M of urea? In this study, the molecular dynamics of DESs as a liquid was simulated at the molecular level. Urea?:?choline chloride as a well-known eutectic mixture was chosen as a model DES. The behavior of the lipase as a biocatalyst was studied in this system. For comparison, the enzyme structure was also simulated in 8M urea. The thermal stability of the enzyme was also evaluated in DESs, water, and 8M urea. The enzyme showed very good conformational stability in the urea?:?choline chloride mixture with about 66% urea (9 M) even at high temperatures. The results are in good agreement with recent experimental observations. In contrast, complete enzyme denaturation occurred in 8M urea with only 12% urea in water. It was found that urea molecules denature the enzyme by interrupting the intra-chain hydrogen bonds in a "direct denaturation mechanism". However, in a urea?:?choline chloride deep eutectic solvent, as a result of hydrogen bonding with choline and chloride ions, urea molecules have a low diffusion coefficient and cannot reach the protein domains. Interestingly, urea, choline, and chloride ions form hydrogen bonds with the surface residues of the enzyme which, instead of lipase denaturation, leads to greater enzyme stability. To the best of our knowledge, this is the first study in which the microstructural properties of a macromolecule are examined in a deep eutectic solvent. PMID:24930496

  10. Molecular size effect of additives on the electro-optical properties of eutectic liquid crystal mixtures

    Microsoft Academic Search

    Yong-il Cho; Cecile Schott; Harry J. Coles

    2005-01-01

    The application of the Liquid Crystal Display (LCD) to TV application needs faster response time to reduce trailing effect of moving picture. Due to the strong anchoring energy of liquid crystals on the alignment layer, the overall response time is increased. Therefore the control of the anchoring strength of the Liquid Crystals at the surface layer in display device could

  11. ASSESSING THE RISK OF SALT WEATHERING IN SANDSTONE BY INSTRU-MENTED MONITORING OF THE ELECTRICAL IMPEDANCE

    E-print Network

    Boyer, Edmond

    ASSESSING THE RISK OF SALT WEATHERING IN SANDSTONE BY INSTRU- MENTED MONITORING OF THE ELECTRICAL, Pfaffenwaldring 2b, 70569 Stuttgart, Germany frank.lehmann@mpa.uni-stuttgart.de ABSTRACT Salt weathering of salts and salt mixtures within the material re- quires adequate measures to avoid further deterioration

  12. Corrosion of materials in molten alkali carbonate salt at 900 degrees C

    Microsoft Academic Search

    R. T. Coyle; T. M. Thomas; P. Schissel

    1985-01-01

    This work was done to assess the compatibility of selected ceramics and alloys with ternary eutectic lithium-sodium-potassium carbonate at 900°C. This salt has been chosen for use in pilot-scale studies of the Direct Absorption Receiver, which will be evaluated at the Advanced Components Test Facility. The candidate containment materials for the receiver were identified in earlier work at SERI and

  13. Phase diagram of the LiNO3-NaNO3-NaCl-Sr(NO3)2 salt system

    NASA Astrophysics Data System (ADS)

    Rasulov, A. I.; Gasanaliev, A. M.; Mamedova, A. K.; Gamataeva, B. Yu.

    2015-04-01

    The phase diagram of the quaternary LiNO3-NaNO3-NaCl-Sr(NO3)2 system is studied by means of differential thermal analysis, and the compositions and crystallization temperatures of nonvariant equilibrium phases are revealed. The temperature dependence of conductivity in eutectic and peritectic salt compositions is investigated.

  14. Pattern Formation and Growth Kinetics in Eutectic Systems

    SciTech Connect

    Jing Teng

    2007-12-01

    Growth patterns during liquid/solid phase transformation are governed by simultaneous effects of heat and mass transfer mechanisms, creation of new interfaces, jump of the crystallization units from liquid to solid and their rearrangement in the solid matrix. To examine how the above processes influence the scale of microstructure, two eutectic systems are chosen for the study: a polymeric system polyethylene glycol-p-dibromobenzene (PEG-DBBZ) and a simple molecular system succinonitrile (SCN)-camphor. The scaling law for SCN-camphor system is found to follow the classical Jackson-Hunt model of circular rod eutectic, where the diffusion in the liquid and the interface energy are the main physics governing the two-phase pattern. In contrast, a significantly different scaling law is observed for the polymer system. The interface kinetics of PEG phase and its solute concentration dependence thus have been critically investigated for the first time by directional solidification technique. A model is then proposed that shows that the two-phase pattern in polymers is governed by the interface diffusion and the interface kinetics. In SCN-camphor system, a new branch of eutectic, elliptical shape rodl, is found in thin samples where only one layer of camphor rods is present. It is found that the orientation of the ellipse can change from the major axis in the direction of the thickness to the direction of the width as the velocity and/or the sample thickness is decreased. A theoretical model is developed that predicts the spacing and orientation of the elliptical rods in a thin sample. The single phase growth patterns of SCN-camphor system were also examined with emphasis on the three-dimensional single cell and cell/dendrite transition. For the 3D single cell in a capillary tube, the entire cell shape ahead of the eutectic front can be described by the Saffmann-Taylor finger only at extremely low growth rate. A 3D directional solidification model is developed to characterize the cell shape and tip undercooling and the experimental results are compared with the predictions of the model. From the investigation of cell/dendrite transition, a model is proposed, from which the condition for the onset of the transition can be obtained.

  15. Microstructure of directionally solidified CrAs/GaAs eutectic

    SciTech Connect

    Holmes, D.E.; Koo, L.Y. [Electronic Materials Engineering, Camarillo, CA (United States)] [Electronic Materials Engineering, Camarillo, CA (United States)

    1995-04-01

    The microstructure of the CrAs/GaAs eutectic directionally solidified by both the Czochralski (Cz) and vertical Bridgman (VB) methods consists of arrays of CrAs rods oriented along the axis of solidification in a GaAs matrix. Microdefects in Cz material including striations, terminations and nucleations, coalescence and branching, and oscillatory instabilities are prevalent and are the result of dynamic morphological adjustment under fluctuating conditions of microscopic solidification. In contrast, selected regions of VB material exhibit near-ideal hexagonal packing of circular rods in the matrix. Cause-effect relationships between microstructure and conditions of solidification were determined and are presented and discussed.

  16. Development of high temperature fasteners using directionally solidified eutectic alloys

    NASA Technical Reports Server (NTRS)

    George, F. D.

    1972-01-01

    The suitability of the eutectics for high temperature fasteners was investigated. Material properties were determined as a function of temperature, and included shear parallel and perpendicular to the growth direction and torsion parallel to it. Techniques for fabricating typical fastener shapes included grinding, creep forming, and direct casting. Both lamellar Ni3Al-Ni3Nb and fibrous (Co,Cr,Al)-(Cr,Co)7C3 alloys showed promise as candidate materials for high temperature fastener applications. A brief evaluation of the performance of the best fabricated fastener design was made.

  17. Interface diffusion in eutectic Pb–Sn solder

    Microsoft Academic Search

    D. Gupta; K. Vieregge; W. Gust

    1998-01-01

    Interface diffusion of 210Pb and 113Sn radioactive tracers in oriented Pb–62wt%Sn eutectic specimens showing lamellar structure has been measured. The product of the interface diffusion coefficient and the width, ?Di, shows an Arrhenius relationship below 400K. The values of the Arrhenius parameters, Qi and ?D°i, for the 210Pb and 113Sn tracers are 84.8kJ\\/mol, 7×10?10m3\\/s and 77kJ\\/mol, 7×10?12m3\\/s, respectively. An interface

  18. Divorced Eutectic Solidification of Mg-Al Alloys

    NASA Astrophysics Data System (ADS)

    Monas, Alexander; Shchyglo, Oleg; Kim, Se-Jong; Yim, Chang Dong; Höche, Daniel; Steinbach, Ingo

    2015-04-01

    We present simulations of the nucleation and equiaxed dendritic growth of the primary hexagonal close-packed ? -Mg phase followed by the nucleation of the ? -phase in interdendritic regions. A zoomed-in region of a melt channel under eutectic conditions is investigated and compared with experiments. The presented simulations allow prediction of the final properties of an alloy based on process parameters. The obtained results give insight into the solidification processes governing the microstructure formation of Mg-Al alloys, allowing their targeted design for different applications.

  19. Creep in Directionally Solidified NiAl-Mo Eutectics

    SciTech Connect

    Dudova, Marie [Institute of Physics, Czech Republic; Kucharova, Kveta [Institute of Physics, Czech Republic; Bartak, Tomas [Institute of Physics, Czech Republic; Bei, Hongbin [ORNL; George, Easo P [ORNL; Somsen, Ch. [Ruhr University, Bochum, Germany; Dlouhy, A. [Institute of Physics of Materials, Brno, Czech Republic

    2011-01-01

    A directionally solidified NiAl-Mo eutectic and an NiAl intermetallic, having respective nominal compositions Ni-45.5Al-9Mo and Ni-45.2Al (at.%), were loaded in compression at 1073 and 1173 K. Formidable strengthening by regularly distributed Mo fibres (average diameter 600 nm, volume fraction 14%) was observed. The fibres can support compression stresses transferred from the plastically deforming matrix up to a critical stress of the order of 2.5 GPa, at which point they yield. Microstructural evidence is provided for the dislocation-mediated stress transfer from the NiAl to the Mo phase.

  20. Directional solidification of Pb-Sn eutectic with vibration

    NASA Technical Reports Server (NTRS)

    Caram, Rubens; Banan, Mohsen; Wilcox, William R.

    1991-01-01

    Pb-Sn eutectic alloy was directionally solidified at 1.4 to 3.2 cm/hr with forced convection induced by axial vibration of the growth ampoule with a frequency of 10 to 40 Hz and an amplitude of 0.5 to 1.0 mm. To determine the exact growth rate, an interface demarcation technique was applied. The lamellar spacing was increased 10 to 40 percent in ingots solidified with vibration compared to those solidified without vibration. The average intensity of convection in the melt under axial vibration of the ampoule was estimated by comparing the experimental results with a theoretical model.

  1. Composition gradients in electrolyzed LiCl-KCl eutectic melts

    NASA Astrophysics Data System (ADS)

    Vallet, C. E.; Heatherly, D. E.; Braunstein, J.

    1983-12-01

    Analysis of transport in a mixed electrolyte has previously predicted significant composition gradients in the LiCl-KCl electrolyte of high temperature LiS/ batteries. Composition gradients in quenched electrolyzed LiCl-KCl eutectic contained in yttria felt are measured with high distance resolution by scanning electron microscopy with energy dispersive X-ray spectroscopy. The reported results include composition profiles of LiCl-KCl coontained in porous Y2O3 and electrolyzed in three cells, two with solid Li-Al electrodes and one with a porous Li-Al anode.

  2. Composition gradients in electrolyzed LiCl-KCL eutectic melts

    SciTech Connect

    Vallet, C.E.; Braunstein, J.; Heatherly, D.E.

    1983-12-01

    Analysis of transport in a mixed electrolyte has previously predicted significant composition gradients in the LiCl-KCl electrolyte of high temperature Li/S batteries. Composition gradients in quenched electrolyzed LiCl-KCl eutectic contained in yttria felt are measured with high distance resolution by scanning electron microscopy with energy dispersive x-ray spectroscopy. The reported results include composition profiles of LiCl-KCl contained in porous Y/sub 2/O/sub 3/ and electrolyzed in three cells, two with solid Li-Al electrodes and one with a porous Li-Al anode.

  3. In situ electrochemical digital holographic microscopy; a study of metal electrodeposition in deep eutectic solvents.

    PubMed

    Abbott, Andrew P; Azam, Muhammad; Ryder, Karl S; Saleem, Saima

    2013-07-16

    This study has shown for the first time that digital holographic microscopy (DHM) can be used as a new analytical tool in analysis of kinetic mechanism and growth during electrolytic deposition processes. Unlike many alternative established electrochemical microscopy methods such as probe microscopy, DHM is both the noninvasive and noncontact, the unique holographic imaging allows the observations and measurement to be made remotely. DHM also provides interferometric resolution (nanometer vertical scale) with a very short acquisition time. It is a surface metrology technique that enables the retrieval of information about a 3D structure from the phase contrast of a single hologram acquired using a conventional digital camera. Here DHM has been applied to investigate directly the electro-crystallization of a metal on a substrate in real time (in situ) from two deep eutectic solvent (DES) systems based on mixture of choline chloride and either urea or ethylene glycol. We show, using electrochemical DHM that the nucleation and growth of silver deposits in these systems are quite distinct and influenced strongly by the hydrogen bond donor of the DES. PMID:23751128

  4. Self-aggregation of sodium dodecyl sulfate within (choline chloride + urea) deep eutectic solvent.

    PubMed

    Pal, Mahi; Rai, Rewa; Yadav, Anita; Khanna, Rajesh; Baker, Gary A; Pandey, Siddharth

    2014-11-11

    Deep eutectic solvents (DESs) have shown tremendous promise as green solvents with low toxicity and cost. Understanding molecular aggregation processes within DESs will not only enhance the application potential of these solvents but also help alleviate some of the limitations associated with them. Among DESs, those comprising choline chloride and appropriate hydrogen-bond donors are inexpensive and easy to prepare. On the basis of fluorescence probe, electrical conductivity, and surface tension experiments, we present the first clear lines of evidence for self-aggregation of an anionic surfactant within a DES containing a small fraction of water. Namely, well-defined assemblies of sodium dodecyl sulfate (SDS) apparently form in the archetype DES Reline comprising a 1:2 molar mixture of choline chloride and urea. Significant enhancement in the solubility of organic solvents that are otherwise not miscible in choline chloride-based DESs is achieved within Reline in the presence of SDS. The remarkably improved solubility of cyclohexane within SDS-added Reline is attributed to the presence of spontaneously formed cyclohexane-in-Reline microemulsions by SDS under ambient conditions. Surface tension, dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), density, and dynamic viscosity measurements along with responses from the fluorescence dipolarity and microfluidity probes of pyrene and 1,3-bis(1-pyrenyl)propane are employed to characterize these aggregates. Such water-free oil-in-DES microemulsions are appropriately sized to be considered as a new type of nanoreactor. PMID:25314953

  5. Low-Temperature Interface Reaction between Titanium and the Eutectic Silver-Copper Brazing Alloy

    E-print Network

    Paris-Sud XI, Université de

    is of 780 °C) should be favourable to the preservation of the microstructure and composition of the titanium1 Low-Temperature Interface Reaction between Titanium and the Eutectic Silver-Copper Brazing Alloy zones formed at 790 °C between solid titanium and liquid Ag-Cu eutectic alloys (pure and Ti

  6. The eutectic characteristic of MC-type carbide precipitation in a DS nickel-base superalloy

    Microsoft Academic Search

    W. R. Sun; J. H. Lee; S. M. Seo; S. J. Choe; Z. Q. Hu

    1999-01-01

    The precipitation of MC-type carbide in a DS nickel-base superalloy has been studied. The nucleating temperature of the MC carbide was determined by analysis. The MC carbide and ? phase were complementary in composition, and the eutectic reaction of (?+MC) took place in different forms at varied solidification rate. The (?+MC) eutectic reaction was an important factor of determining the

  7. Lead–gold eutectic: An alternative liquid target material candidate for high power spallation neutron sources

    Microsoft Academic Search

    Marisa Medarde; Rainer Moormann; Ruggero Frison; Robert J. Pu?niak; Ekaterina Pomjakushina; Kazimierz Conder; Ernests Platacis; Yong Dai; Daniela Kiselev; Luca Zanini; Szabina Török; Peter Zagyvai; Stephan Heinitz; Jörg Neuhausen; Dorothea Schumann; Knud Thomsen

    2011-01-01

    One of the main technical concerns of Megawatt-class spallation neutron sources is the removal of the heat deposited in the target station. A way to overcome it is to use targets consisting of flowing liquid metals, but the already tested materials – mercury and lead–bismuth eutectic (LBE) – are not unproblematic. We show here that another eutectic alloy containing lead

  8. Competitive stochastic growth model for the 3D morphology of eutectic Si in Al-Si alloys

    E-print Network

    Schmidt, Volker

    Competitive stochastic growth model for the 3D morphology of eutectic Si in Al-Si alloys Gerd for the simulation of the 3D morphology of eutectic silicon in Al-Si alloys, which represents the colonies-Si alloys, coral-like eutectic Si, stochastic growth model, multivariate time series, FIB-SEM tomography

  9. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 9, NO. 1, MARCH 2000 3 Localized Silicon Fusion and Eutectic Bonding for

    E-print Network

    Lin, Liwei

    and Eutectic Bonding for MEMS Fabrication and Packaging Y. T. Cheng, Liwei Lin, Member, IEEE, and Khalil Najafi, Fellow, IEEE Abstract--Silicon fusion and eutectic bonding processes based on the technique of localized separately in the silicon-to-glass fusion bonding and silicon-to-gold eutectic bonding experiments

  10. Ternary eutectic growth of nanostructured thermoelectric Ag-Pb-Te materials

    SciTech Connect

    Wu, Hsin-jay; Chen, Sinn-wen [Department of Chemical Engineering, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd., Hsin-Chu 300, Taiwan (China); Foo, Wei-jian [Engineering Science Programme, National University of Singapore, Blk EA, 06-10, 9 Engineering Drive, Singapore 117576 (Singapore); Jeffrey Snyder, G. [Materials Science, California Institute of Technology, 1200 California Blvd., Pasadena, California 91125 (United States)

    2012-07-09

    Nanostructured Ag-Pb-Te thermoelectric materials were fabricated by unidirectionally solidifying the ternary Ag-Pb-Te eutectic and near-eutectic alloys using the Bridgeman method. Specially, the Bridgman-grown eutectic alloy exhibited a partially aligned lamellar microstructure, which consisted of Ag{sub 5}Te{sub 3} and Te phases, with additional 200-600 nm size particles of PbTe. The self-assembled interfaces altered the thermal and electronic transport properties in the bulk Ag-Pb-Te eutectic alloy. Presumably due to phonon scattering from the nanoscale microstructure, a low thermal conductivity ({kappa} = 0.3 W/mK) was achieved of the eutectic alloy, leading to a zT peak of 0.41 at 400 K.

  11. Localized removal of the Au-Si eutectic bonding layer for the selective release of microstructures

    NASA Astrophysics Data System (ADS)

    Gradin, Henrik; Braun, Stefan; Stemme, Göran; van der Wijngaart, Wouter

    2009-10-01

    This paper presents and investigates a novel technique for the footprint and thickness-independent selective release of Au-Si eutectically bonded microstructures through the localized removal of their eutectic bond interface. The technique is based on the electrochemical removal of the gold in the eutectic layer and the selectivity is provided by patterning the eutectic layer and by proper electrical connection or isolation of the areas to be etched or removed, respectively. The gold removal results in a porous silicon layer, acting similar to standard etch holes in a subsequent sacrificial release etching. The paper presents the principle and the design requirements of the technique. First test devices were fabricated and the method successfully demonstrated. Furthermore, the paper investigates the release mechanism and the effects of different gold layouts on both the eutectic bonding and the release procedure.

  12. Thermal Properties and Thermal Reliability of Capric Acid\\/Stearic Acid Mixture for Latent Heat Thermal Energy Storage

    Microsoft Academic Search

    A. Kara?pekl?; A. Sar?; K. Kaygusuz

    2009-01-01

    This study focuses on the preparation of capric acid\\/stearic acid mixture as novel phase change material for latent heat thermal energy storage and determination of its thermal properties and thermal reliability by using differential scanning calorimetry analysis technique. The differential scanning calorimetry results indicated that the capric acid\\/stearic acid mixture with eutectic composition (83\\/17 wt%) was suitable phase change material

  13. Eutectic Solder Bonding for Highly Manufacturable Microelectromechanical Systems Probe Card

    NASA Astrophysics Data System (ADS)

    Kim, Bonghwan

    2011-06-01

    We developed eutectic solder bonding for the microelectromechanical systems (MEMS) probe card. We tested various eutectic solder materials, such as Sn, AgSn, and AuSn, and investigated the bonding ability of Sn-based multi-element alloys and their resistance to chemical solutions. The Sn-based alloys were formed by sputtering, electroplating, and the use of solder paste. According to our experimental results, Sn-rich solders, such as Ag3.5Sn, Ag3.5Sn96Cu0.5, and Sn, were severely damaged by silicon wet etchant such as potassium hydroxide (KOH) and tetramethylammonium hydroxide (TMAH). On the other hand Au80Sn20 was resistant to those chemicals. In order to verify the joint bondability of the solders, we used a cantilever probe beam, and bump which were made of nickel and nickel alloy. After flip-chip bonding of the cantilever beam and the bump with Au80Sn20 solder paste, we measured the contact force to verify the mechanical strength. We then re-inspected it with X-rays and found no voids in the joint.

  14. Ice/hydrohalite crystallization structures in sub-eutectic freezing experiments in the system NaCl-H20 and possible implications for the properties of frozen brines in Europa: A preliminary report

    NASA Astrophysics Data System (ADS)

    Rieck, K.; Kirby, S. H.; Stern, L. A.

    2005-12-01

    Sulfates are likely to be the most abundant solutes in the subsurface Europan liquid ocean. NaCl may also be a significant component of such liquids based on the compositions of stony meteorites like those thought to be among the source materials for the silicates in Europa's interior. The system NaCl-H20 exhibits a eutectic at -20.8°C and 23.3 weight percent NaCl between ice Ih and hydrohalite (NaCl.2H20). This low eutectic temperature compared to Mg and Na sulfate hydrate/ice eutectics indicates that hydrohalite should be among the last salts to crystallize in brine upwellings along rifts and other places where resurfacing by melt extrusion occurs on Europa. We conducted a suite of freezing experiments on NaCl brines with 20.3, 23.3, and 26.6 (saturated) weight percent NaCl by holding these liquids at a few degrees below the eutectic temperature. These runs produced ice-rich, eutectic and hydrohalite-rich aggregates of both phases, respectively, as confirmed by cryogenic x-ray diffraction and x-ray fluorescence spectroscopy. Based on direct observations of crystals forming at the tops and bottoms of the sample chambers and on refractive index measurements of subsequently melted sample material, marked fractional crystallization and segregation by density of ice, hydrohalite, and residual liquids occurred in the 20.3 and 26.6% samples and less so in for the eutectic composition. Crystallization of very fine grained eutectic intergrowths was recognized in cryogenic SEM images of all these samples and they were especially prominent in samples frozen from saturated brine. These samples were very difficult to cleave compared to pure polycrystalline ice, and hence are likely to have high fracture toughness. Direct measurements of this property and also the effects of partial melting on ductile flow rates are planned on such samples. Refracturing of such regions of fine eutectoid ice/hydrohalite intergrowths is likely to be inhibited in refrozen rifts compared to more ice-rich regions on Europa.

  15. Pyrochemical process for extracting plutonium from an electrolyte salt

    DOEpatents

    Mullins, Lawrence J. (Los Alamos, NM); Christensen, Dana C. (Los Alamos, NM)

    1984-01-01

    A pyrochemical process for extracting plutonium from a plutonium-bearing salt is disclosed. The process is particularly useful in the recovery of plutonium from electrolyte salts which are left over from the electrorefining of plutonium. In accordance with the process, the plutonium-bearing salt is melted and mixed with metallic calcium. The calcium reduces ionized plutonium in the salt to plutonium metal, and also causes metallic plutonium in the salt, which is typically present as finely dispersed metallic shot, to coalesce. The reduced and coalesced plutonium separates out on the bottom of the reaction vessel as a separate metallic phase which is readily separable from the overlying salt upon cooling of the mixture. Yields of plutonium are typically on the order of 95%. The stripped salt is virtually free of plutonium and may be discarded to low-level waste storage.

  16. Pyrochemical process for extracting plutonium from an electrolyte salt

    DOEpatents

    Mullins, L.J.; Christensen, D.C.

    1982-09-20

    A pyrochemical process for extracting plutonium from a plutonium-bearing salt is disclosed. The process is particularly useful in the recovery of plutonium for electrolyte salts which are left over from the electrorefining of plutonium. In accordance with the process, the plutonium-bearing salt is melted and mixed with metallic calcium. The calcium reduces ionized plutonium in the salt to plutonium metal, and also causes metallic plutonium in the salt, which is typically present as finely dispersed metallic shot, to coalesce. The reduced and coalesced plutonium separates out on the bottom of the reaction vessel as a separate metallic phase which is readily separable from the overlying salt upon cooling of the mixture. Yields of plutonium are typically on the order of 95%. The stripped salt is virtually free of plutonium and may be discarded to low-level waste storage.

  17. Preliminary study of the electrolysis of aluminum sulfide in molten salts

    SciTech Connect

    Minh, N.Q.; Loutfy, R.O.; Yao, N.P.

    1983-02-01

    A preliminary laboratory-scale study of the electrolysis of aluminum sulfide in molten salts investigated the (1) solubility of Al/sub 2/S/sub 3/ in molten salts, (2) electrochemical behavior of Al/sub 2/S/sub 3/, and (3) electrolysis of Al/sub 2/S/sub 3/ with the determination of current efficiency as a function of current density. The solubility measurements show that MgCl/sub 2/-NaCl-KCl eutectic electrolyte at 1023 K can dissolve up to 3.3 mol % sulfide. The molar ratio of sulfur to aluminum in the eutectic is about one, which suggests that some sulfur remains undissolved, probably in the form of MgS. The experimental data and thermodynamic calculations suggest that Al/sub 2/S/sub 3/ dissolves in the eutectic to form AlS/sup +/ species in solution. Addition of AlCl/sub 3/ to the eutectic enhances the solubility of Al/sub 2/S/sub 3/; the solubility increases with increasing AlCl/sub 3/ concentration. The electrode reaction mechanism for the electrolysis of Al/sub 2/S/sub 3/ was elucidated by using linear sweep voltammetry. The cathodic reduction of aluminum-ion-containing species to aluminum proceeds by a reversible, diffusion-controlled, three-electron reaction. The anodic reaction involves the two-electron discharge of sulfide-ion-containing species, followed by the fast dimerization of sulfur atoms to S/sub 2/. Electrolysis experiments show that Al/sub 2/S/sub 3/ dissolved in molten MgCl/sub 2/-NaCl-KCl eutectic or in eutectic containing AlCl/sub 3/ can be electrolyzed to produce aluminum and sulfur. In the eutectic at 1023 K, the electrolysis can be conducted up to about 300 mA/cm/sup 2/ for the saturation solubility of Al/sub 2/S/sub 3/. Although these preliminary results are promising, additional studies are needed to elucidate many critical operating parameters before the technical potential of the electrolysis can be accurately assessed. 20 figures, 18 tables.

  18. Electrolyte salts for power sources

    DOEpatents

    Doddapaneni, Narayan (10516 Royal Birkdale, NE., Albuquerque, NM 87111); Ingersoll, David (5824 Mimosa Pl., NE., Albuquerque, NM 87111)

    1995-01-01

    Electrolyte salts for power sources comprising salts of phenyl polysulfonic acids and phenyl polyphosphonic acids. The preferred salts are alkali and alkaline earth metal salts, most preferably lithium salts.

  19. Electrolyte salts for power sources

    DOEpatents

    Doddapaneni, N.; Ingersoll, D.

    1995-11-28

    Electrolyte salts are disclosed for power sources comprising salts of phenyl polysulfonic acids and phenyl polyphosphonic acids. The preferred salts are alkali and alkaline earth metal salts, most preferably lithium salts. 2 figs.

  20. PySALT: the SALT science pipeline

    NASA Astrophysics Data System (ADS)

    Crawford, Steven M.; Still, Martin; Schellart, Pim; Balona, Luis; Buckley, David A. H.; Dugmore, Garith; Gulbis, Amanda A. S.; Kniazev, Alexei; Kotze, Marissa; Loaring, Nicola; Nordsieck, Kenneth H.; Pickering, Timothy E.; Potter, Stephen; Romero Colmenero, Encarni; Vaisanen, Petri; Williams, Theodore; Zietsman, Ewald

    2010-07-01

    PySALT is the python/PyRAF-based data reduction and analysis pipeline for the Southern African Large Telescope (SALT), a modern 10m class telescope with a large user community consisting of 13 partner institutions. The two first generation instruments on SALT are SALTICAM, a wide-field imager, and the Robert Stobie Spectrograph (RSS). Along with traditional imaging and spectroscopy modes, these instruments provide a wide range of observing modes, including Fabry-Perot imaging, polarimetric observations, and high-speed observations. Due to the large user community, resources available, and unique observational modes of SALT, the development of reduction and analysis software is key to maximizing the scientific return of the telescope. PySALT is developed in the Python/PyRAF environment and takes advantage of a large library of open-source astronomical software. The goals in the development of PySALT are: (1) Provide science quality reductions for the major operational modes of SALT, (2) Create analysis tools for the unique modes of SALT, and (3) Create a framework for the archiving and distribution of SALT data. The data reduction software currently provides support for the reduction and analysis of regular imaging, high-speed imaging, and long slit spectroscopy with planned support for multi-object spectroscopy, high-speed spectroscopy, Fabry-Perot imaging, and polarimetric data sets. We will describe the development and current status of PySALT and highlight its benefits through early scientific results from SALT.

  1. Effects of ultrasound and temperature on copper electro reduction in Deep Eutectic Solvents (DES).

    PubMed

    Mandroyan, Audrey; Mourad-Mahmoud, Mahmoud; Doche, Marie-Laure; Hihn, Jean-Yves

    2014-11-01

    This paper concerns a preliminary study for a new copper recovery process from ionic solvent. The aim of this work is to study the reduction of copper in Deep Eutectic Solvent (choline chloride-ethylene glycol) and to compare the influence of temperature and the ultrasound effects on kinetic parameters. Solutions were prepared by dissolution of chloride copper salt CuCl2 (to obtain Copper in oxidation degree II) or CuCl (to obtain Copper in oxidation degree I) and by leaching metallic copper directly in DES. The spectrophotometry UV-visible analysis of the leached solution showed that the copper soluble form obtained is at oxidation degree I (Copper I). Both cyclic voltammetry and linear voltammetry were performed in the three solutions at three temperatures (25, 50 and 80°C) and under ultrasonic conditions (F=20kHz, PT=5.8W) to calculate the mass transfer diffusion coefficient kD and the standard rate coefficient k°. These parameters are used to determine that copper reduction is carried out via a mixed kinetic-diffusion control process. Temperature and ultrasound have the same effect on mass transfer for reduction of Cu(II)/Cu(I). On the other hand, temperature is more beneficial than ultrasound for mass transfer of Cu(I)/Cu. Standard rate constant improvement due to temperature increase is of the same order as that obtained with ultrasound. But, by combining higher temperature and ultrasound (F=20kHz, PT=5.6W at 50°C), reduction limiting current is increased by a factor of 10 compared to initial conditions (T=25°C, silent), because ultrasonic stirring is more efficient in lower viscosity fluid. These values can be considered as key-parameters in the design of copper recovery in global processes using ultrasound. PMID:24629581

  2. A green deep eutectic solvent-based aqueous two-phase system for protein extracting.

    PubMed

    Xu, Kaijia; Wang, Yuzhi; Huang, Yanhua; Li, Na; Wen, Qian

    2015-03-15

    As a new type of green solvent, deep eutectic solvent (DES) has been applied for the extraction of proteins with an aqueous two-phase system (ATPS) in this work. Four kinds of choline chloride (ChCl)-based DESs were synthesized to extract bovine serum albumin (BSA), and ChCl-glycerol was selected as the suitable extraction solvent. Single factor experiments have been done to investigate the effects of the extraction process, including the amount of DES, the concentration of salt, the mass of protein, the shaking time, the temperature and PH value. Experimental results show 98.16% of the BSA could be extracted into the DES-rich phase in a single-step extraction under the optimized conditions. A high extraction efficiency of 94.36% was achieved, while the conditions were applied to the extraction of trypsin (Try). Precision, repeatability and stability experiments were studied and the relative standard deviations (RSD) of the extraction efficiency were 0.4246% (n=3), 1.6057% (n=3) and 1.6132% (n=3), respectively. Conformation of BSA was not changed during the extraction process according to the investigation of UV-vis spectra, FT-IR spectra and CD spectra of BSA. The conductivity, dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to explore the mechanism of the extraction. It turned out that the formation of DES-protein aggregates play a significant role in the separation process. All the results suggest that ChCl-based DES-ATPS are supposed to have the potential to provide new possibilities in the separation of proteins. PMID:25732422

  3. Microstructure and Strength of NiTi-Nb Eutectic Braze Joining NiTi Wires

    NASA Astrophysics Data System (ADS)

    Wang, Liqiang; Wang, Cong; Dunand, David C.

    2015-04-01

    NiTi wires were brazed together via liquid eutectic formation between NiTi and Nb powders deposited at the wire contact region. The brazed region shows proeutectic NiTi(Nb) in contact with the wires, sandwiching a NiTi-Nb eutectic structure, whose microhardness and stiffness, as characterized via nanoindentation, are higher than the NiTi wires, while also showing signs of high ductility. NiTi-Nb eutectic bonding may thus be a viable approach for producing shape-memory NiTi scaffolds brazed from stacked, woven, or braided wires.

  4. Evaporation of mercury impurity from liquid lead-bismuth eutectic

    NASA Astrophysics Data System (ADS)

    Aerts, A.; Danaci, S.; Gonzalez Prieto, B.; Van den Bosch, J.; Neuhausen, J.

    2014-05-01

    The equilibrium evaporation of mercury from dilute solutions in liquid lead-bismuth eutectic (LBE) was studied in argon atmosphere. Mercury present as impurity in LBE was evaporated and detected by atomic fluorescence spectroscopy. A method which could accurately simulate the experimental data was developed. Coefficients of the Henry constant temperature correlation for mercury dissolved in LBE were determined. Experiments with samples from several different batches of LBE revealed that mercury at mole fractions between 10-6 and 10-12 and temperatures between 150 and 350 °C evaporated from liquid LBE close to ideal behavior. Evaporation of mercury from solid LBE on the other hand was unexpectedly high. These results are important for safety evaluations of LBE based spallation targets and accelerator driven systems.

  5. Deep eutectic solvent pretreatment and subsequent saccharification of corncob.

    PubMed

    Procentese, Alessandra; Johnson, Erin; Orr, Valerie; Garruto Campanile, Anna; Wood, Jeffery A; Marzocchella, Antonio; Rehmann, Lars

    2015-09-01

    Ionic liquid (ILs) pretreatment of lignocellulosic biomass has attracted broad scientific interest, despite high costs, possible toxicity and energy intensive recycling. An alternative group of ionic solvents with similar physicochemical properties are deep eutectic solvents (DESs). Corncob residues were pretreated with three different DES systems: choline chloride and glycerol, choline chloride and imidazole, choline chloride and urea. The pretreated biomass was characterised in terms of lignin content, sugars concentration, enzymatic digestibility and crystallinity index. A reduction of lignin and hemicellulose content resulted in increased crystallinity of the pretreated biomass while the crystallinity of the cellulose fraction could be reduced, depending on DES system and operating conditions. The subsequent enzymatic saccharification was enhanced in terms of rate and extent. A total of 41g fermentable sugars (27g glucose and 14g xylose) could be recovered from 100g corncob, representing 76% (86% and 63%) of the initially available carbohydrates. PMID:26005926

  6. Directional solidification of Pb-Sn eutectic with vibration

    NASA Technical Reports Server (NTRS)

    Caram, Rubens; Banan, Mohsen; Wilcox, William R.

    1991-01-01

    Pb-Sn eutectic alloy was directionally solidified at 1.4 to 3.2 cm/h with forced convection induced by axial vibration of the growth ampoule with a frequency of 10 to 40 Hz and an amplitude of 0.5 to 1.0 mm. To determine the exact growth rate, an interface demarcation technique was applied. The lamellar spacing was increased 10 to 40 percent in ingots solidified with vibration, compared to those solidified without vibration. The number of grain boundaries was increased by vibration. The average intensity of convection in the melt under axial vibration of the ampoule was estimated by comparing the experimental results with a theoretical model.

  7. Directional solidification of Pb-Sn eutectics with vibration

    NASA Technical Reports Server (NTRS)

    Caram, Rubens; Banan, Mohsen; Wilcox, William R.

    1991-01-01

    Pb-Sn eutectic alloy was directionally solidified at 1.4 to 3.2 cm/hr with forced convection induced by axial vibration of the growth ampoule with a frequency of 10 to 40 Hz and an amplitude of 0.5 to 1.0 mm. To determine the exact growth rate, an interface demarcation technique was applied. The lamellar spacing was increased 10 to 40 percent in ingots solidified with vibration compared to those solidified without vibration. The number of grain boundaries was increased by vibration. The average intensity of convection in the melt under axial vibration of the ampoule was estimated by comparing the experimental results with a theoretical model.

  8. Traceable Co-C eutectic points for thermocouple calibration

    SciTech Connect

    Jahan, F.; Ballico, M. J. [National Measurement Institute, Lindfield, NSW 2070 (Australia)] [National Measurement Institute, Lindfield, NSW 2070 (Australia)

    2013-09-11

    National Measurement Institute of Australia (NMIA) has developed a miniature crucible design suitable for measurement by both thermocouples and radiation thermometry, and has established an ensemble of five Co-C eutectic-point cells based on this design. The cells in this ensemble have been individually calibrated using both ITS-90 radiation thermometry and thermocouples calibrated on the ITS-90 by the NMIA mini-coil methodology. The assigned ITS-90 temperatures obtained using these different techniques are both repeatable and consistent, despite the use of different furnaces and measurement conditions. The results demonstrate that, if individually calibrated, such cells can be practically used as part of a national traceability scheme for thermocouple calibration, providing a useful intermediate calibration point between Cu and Pd.

  9. Lead-bismuth eutectic as advanced reactor collant : operational experience

    SciTech Connect

    Woloshun, K. A. (Keith A.); Watts, V. (Valentina); Li, N. (Ning)

    2004-01-01

    Some proposed advanced reactor concepts would be cooled by lead or lead-bismuth eutectic (LBE). An LBE test loop was designed and built at Los Alamos to develop the engineering and materials technology necessary to successfully implement LBE as a coolant (Fig. 1). Operational since December 2001, this test loop has been used to develop and demonstrate safe operation, oxygen concentration and metal corrosion control, instrumentation, thermal-hydraulic performance of heat exchangers and recuperators, and free convection and forced pumping. This paper discusses the technology development and lessons learned from the operation of this facility. A LBE test loop has been operational since December 2001. Using procedures, training, and engineering controls, this loop has operated without an accident. Continuous improvements in operation procedures and instrumentation over these years have resulted in a facility of high reliability, providing the groundwork for the use of LBE as a reactor coolant for temperatures up to 550 C.

  10. Ion Fractionation at the Surface of Aqueous Inorganic Salt Solutions by Means of a `Film Centrifuge'

    Microsoft Academic Search

    P. H. Koske; H. Martin

    1972-01-01

    The predictions of Gibbs's lawnd the electrolyte theory about the (negative) adsorption of salts on the surface of aqueous salt solutions are compared with the results of an analysis of very thin surface films skimmed by means of a 'film centrifuge' from a solution containing two different salts. The separation effects observed on the salt mixtures CsC1\\/NaC1, BaCl\\/ NaC1, BaCl\\/CsC1,

  11. Highlights of the Salt Extraction Process

    NASA Astrophysics Data System (ADS)

    Abbasalizadeh, Aida; Seetharaman, Seshadri; Teng, Lidong; Sridhar, Seetharaman; Grinder, Olle; Izumi, Yukari; Barati, Mansoor

    2013-11-01

    This article presents the salient features of a new process for the recovery of metal values from secondary sources and waste materials such as slag and flue dusts. It is also feasible in extracting metals such as nickel and cobalt from ores that normally are difficult to enrich and process metallurgically. The salt extraction process is based on extraction of the metals from the raw materials by a molten salt bath consisting of NaCl, LiCl, and KCl corresponding to the eutectic composition with AlCl3 as the chlorinating agent. The process is operated in the temperature range 973 K (700°C) to 1173 K (900°C). The process was shown to be successful in extracting Cr and Fe from electric arc furnace (EAF) slag. Electrolytic copper could be produced from copper concentrate based on chalcopyrite in a single step. Conducting the process in oxygen-free atmosphere, sulfur could be captured in the elemental form. The method proved to be successful in extracting lead from spent cathode ray tubes. In order to prevent the loss of AlCl3 in the vapor form and also chlorine gas emission at the cathode during the electrolysis, liquid aluminum was used. The process was shown to be successful in extracting Nd and Dy from magnetic scrap. The method is a highly promising process route for the recovery of strategic metals. It also has the added advantage of being environmentally friendly.

  12. Chemistry control and corrosion mitigation of heat transfer salts for the fluoride salt reactor (FHR)

    SciTech Connect

    Kelleher, B. C.; Sellers, S. R.; Anderson, M. H.; Sridharan, K.; Scheele, R. D. [Dept. of Engineering Physics, Univ.of Wisconsin - Madison, 1500 Engineering Drive, Madison, WI 53706 (United States)

    2012-07-01

    The Molten Salt Reactor Experiment (MSRE) was a prototype nuclear reactor which operated from 1965 to 1969 at Oak Ridge National Laboratory. The MSRE used liquid fluoride salts as a heat transfer fluid and solvent for fluoride based {sup 235}U and {sup 233}U fuel. Extensive research was performed in order to optimize the removal of oxide and metal impurities from the reactor's heat transfer salt, 2LiF-BeF{sub 2} (FLiBe). This was done by sparging a mixture of anhydrous hydrofluoric acid and hydrogen gas through the FLiBe at elevated temperatures. The hydrofluoric acid reacted with oxides and hydroxides, fluorinating them while simultaneously releasing water vapor. Metal impurities such as iron and chromium were reduced by hydrogen gas and filtered out of the salt. By removing these impurities, the corrosion of reactor components was minimized. The Univ. of Wisconsin - Madison is currently researching a new chemical purification process for fluoride salts that make use of a less dangerous cleaning gas, nitrogen trifluoride. Nitrogen trifluoride has been predicted as a superior fluorinating agent for fluoride salts. These purified salts will subsequently be used for static and loop corrosion tests on a variety of reactor materials to ensure materials compatibility for the new FHR designs. Demonstration of chemistry control methodologies along with potential reduction in corrosion is essential for the use of a fluoride salts in a next generator nuclear reactor system. (authors)

  13. Effect of high magnetic fields on the microstructure in directionally solidified Bi Mn eutectic alloy

    NASA Astrophysics Data System (ADS)

    Li, Xi; Ren, Zhongming; Fautrelle, Yves

    2007-02-01

    The eutectic Bi/MnBi alloy has been directionally solidified in the presence of an axial magnetic field to investigate the influence of high magnetic fields on the growth of eutectic Bi/MnBi. The morphology and magnetic properties of the specimens indicate that a high magnetic field promotes the formation of MnBi fiber and makes the directional solidification structure of the eutectic more regular. The MnBi inter-rod spacing and rod diameters gradually increase with the magnetic field intensity. Furthermore, the magnetic field enhances the faceted growth of MnBi phase and the magnetic coercivities of the alloy. This may be attributed to the magnetic anisotropy and the shift of the eutectic point by the magnetic field.

  14. Pre-eutectic densification in MgF/sub 2/-CaF/sub 2/

    SciTech Connect

    Hu, S C; De Jonghe, L C

    1982-04-01

    Increased densification rates were found as much as 200/sup 0/C below the eutectic temperature (980/sup 0/C) for MgF/sub 2/ containing small amounts of CaF/sub 2/. Constant heating rate and constant temperature sintering data, as well as microstructural developments indicated that solid state grain-boundary transport rates had been enhanced by the eutectic forming additive. The effect saturated at about 1 wt % CaF/sub 2/. The results suggest that densification of ceramic powders could be favorably affected without a substantial increase in the grain growth rate, by the addition of small amounts of eutectic forming additives, and sintering below the eutectic temperature. 6 figures.

  15. Effect of boron on the microstructure of near-eutectic Al-Si alloys

    SciTech Connect

    Wu Yuying [Key Laboratory of Materials Liquid Structure and Heredity, Ministry of Education, Shandong University, Jinan 250061, Shandong (China)]. E-mail: wyy532001@163.com; Liu Xiangfa [Key Laboratory of Materials Liquid Structure and Heredity, Ministry of Education, Shandong University, Jinan 250061, Shandong (China); Bian Xiufang [Key Laboratory of Materials Liquid Structure and Heredity, Ministry of Education, Shandong University, Jinan 250061, Shandong (China)

    2007-02-15

    The effect of boron on the microstructure of a near-eutectic Al-Si alloy (ZL109) was investigated by scanning electron microscopy (SEM) and electron beam microprobe analysis (EPMA). It was found that {alpha}-Al dendrites and eutectic clusters were significantly refined by the addition of boron. Another interesting discovery is that the near-eutectic alloy exhibited hypereutectic structure characteristics when the level of boron added exceeds 0.3%, i.e., primary Si is precipitated in the eutectic microstructure. A new type of nucleation substrate for the primary Si is found, Al {sub x}Ca {sub m}B {sub n}Si. This appears to be the main reason for the precipitation of primary Si.

  16. Study of uranium solubility in gallium-indium eutectic alloy by emf method

    NASA Astrophysics Data System (ADS)

    Volkovich, V. A.; Maltsev, D. S.; Yamshchikov, L. F.; Osipenko, A. G.; Raspopin, S. P.; Kormilitsyn, M. V.

    2013-02-01

    Activity, activity coefficients and solubility of uranium in Ga-In eutectic alloy as well as activity of uranium in U-Ga and U-In alloys were determined between 573 and 1073 K using electromotive force (emf) method.

  17. In Vitro and In Vivo toxicity profiling of ammonium-based deep eutectic solvents.

    PubMed

    Hayyan, Maan; Looi, Chung Yeng; Hayyan, Adeeb; Wong, Won Fen; Hashim, Mohd Ali

    2015-01-01

    The cytotoxic potential of ammonium-based deep eutectic solvents (DESs) with four hydrogen bond donors, namely glycerine (Gl), ethylene glycol (EG), triethylene glycol (TEG) and urea (U) were investigated. The toxicity of DESs was examined using In Vitro cell lines and In Vivo animal model. IC50 and selectivity index were determined for the DESs, their individual components and their combinations as aqueous solutions for comparison purposes. The cytotoxicity effect of DESs varied depending on cell lines. The IC50 for the GlDES, EGDES, UDES and TEGDES followed the sequence of TEGDES< GlDES< EGDES< UDES for OKF6, MCF-7, A375, HT29 and H413, respectively. GlDES was selective against MCF-7 and A375, EGDES was selective against MCF-7, PC3, HepG2 and HT29, UDES was selective against MCF-7, PC3, HepG2 and HT29, and TEGDES was selective against MCF-7 and A375. However, acute toxicity studies using ICR mice showed that these DESs were relatively toxic in comparison to their individual components. DES did not cause DNA damage, but it could enhance ROS production and induce apoptosis in treated cancer cells as evidenced by marked LDH release. Furthermore, the examined DESs showed less cytotoxicity compared with ionic liquids. To the best of our knowledge, this is the first time that combined In Vitro and In Vivo toxicity profiles of DESs were being demonstrated, raising the toxicity issue of these neoteric mixtures and their potential applicability to be used for therapeutic purposes. PMID:25679975

  18. Phase composition, microstructure and electrical properties of alumina-zirconia eutectic composites

    Microsoft Academic Search

    R. ?i?ka; V. Trnovcová; M. Yu Starostin

    2002-01-01

    Oxide eutectic composites prepared by a directional solidification are noticeable for their good mechanical properties and\\u000a high temperature stability in oxidizing environments. In this paper we study the influence of stabilizers (Y, Sc) on the phase\\u000a composition, microstructure and electrical properties of Al2O3 - ZrO2 eutectic composites. At a hypereutectic composition of the melt, we have prepared the composites with

  19. Fracture behavior of directionally solidified YâAlâOââ\\/AlâOâ eutectic fiber

    Microsoft Academic Search

    Jenn-Ming Yang; S. M. Jeng; Sekyung Chang

    1996-01-01

    The strength and fracture of a directionally solidified YâAlâOââ\\/AlâOâ eutectic fiber were investigated. The fiber was grown continuously by an edge-defined film-fed growth technique. The microstructure was characterized using X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. The tensile strength and Weibull`s modulus of the eutectic fibers were determined in the as-fabricated state and after extended thermal exposure at 1,460

  20. Deformation and fracture of a directionally solidified NiAl28Cr6Mo eutectic alloy

    Microsoft Academic Search

    X. F. Chen; D. R. Johnson; R. D. Noebe; B. F. Oliver

    1995-01-01

    A directionally solidified alloy based on the NiAl-(Cr, Mo) eutectic was examined by transmission and scanning electron microscopy to characterize the microstructure and room temperature deformation and fracture behavior. The microstructure consisted of a lamellar morphology with a group of zone axes (111) growth direction for both the NiAl and (Cr, Mo) phases. The interphase boundary between the eutectic phases

  1. The aging response of Al-Cu and Al-Cu-Mg directionally solidified eutectics

    Microsoft Academic Search

    C. G. Rhodes; G. Garmong

    1972-01-01

    The microstructure and mechanical properties of directionally solidified Al-Cu eutectic and the microstructure of directionally\\u000a solidified Al-Cu-Mg eutectic alloys have been studied in as-grown, quenched, and aged conditions. In both systems the microstructure\\u000a of the aluminum-rich ? phase responded to aging treatments in a manner like that of dilute alloys of comparable composition.\\u000a The cooling rate of the alloys from

  2. Microstructure and crystallographic orientation relationship in directionally solidified Mg–Mg 17Al 12eutectic

    Microsoft Academic Search

    Sigrid Guldberg; Nils Ryum

    2000-01-01

    The microstructure and crystallographic orientation relationship of the Mg- and the Mg17Al12-phase in a directionally solidified Mg–Al-eutectic have been study in the light microscope and in the scanning electron microscope equipped with an electron back scattering facility. The effects of the addition of small amounts of Sr on the microstructure were also studied. The Mg–Al-eutectic solidified with a lamellar morphology

  3. Suppression of ambient temperature creep by eutectic phase for hexagonal close-packed metal

    NASA Astrophysics Data System (ADS)

    Matsunaga, Tetsuya; Abe, Tomonori; Itoh, Shun; Satoh, Yuhki; Abe, Hiroaki

    2014-03-01

    Zr-Si alloys were designed to contain eutectic phase surrounding the parent phase to suppress creep behavior of claddings. Creep tests conducted at 294-573 K showed that creep behavior was inhibited and that the creep failure time of new Zr alloy became longer than that of a conventional alloy: Zircaloy-4. Results show that the eutectic phase can suppress creep at operating temperatures prevailing in current nuclear power plants.

  4. Eutectic structures in friction spot welding joint of aluminum alloy to copper

    SciTech Connect

    Shen, Junjun, E-mail: junjun.shen@hzg.de; Suhuddin, Uceu F. H.; Cardillo, Maria E. B.; Santos, Jorge F. dos [Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Materials Mechanics, Solid-State Joining Processes, Max-Planck-Str. 1, 21502 Geesthacht (Germany)

    2014-05-12

    A dissimilar joint of AA5083 Al alloy and copper was produced by friction spot welding. The Al-MgCuAl{sub 2} eutectic in both coupled and divorced manners were found in the weld. At a relatively high temperature, mass transport of Cu due to plastic deformation, material flow, and atomic diffusion, combined with the alloy system of AA5083 are responsible for the ternary eutectic melting.

  5. Effect of erbium on properties and microstructure of Al-Si eutectic alloy

    Microsoft Academic Search

    Pengfei XING; Bo GAO; Yanxin ZHUANG; Kaihua LIU; Ganfeng TU

    2010-01-01

    Eutectic Al-12.6 wt.%Si alloys with various contents of the rare earth element Er were prepared by the conventional casting technique. The effect of Er on the microstructure and properties of the eutectic Al-Si alloys was investigated using optical microscopy, scanning electron microscopy as well as the friction and wear tests. It was found that the addition of Er obviously improved

  6. Eutectic structures in friction spot welding joint of aluminum alloy to copper

    NASA Astrophysics Data System (ADS)

    Shen, Junjun; Suhuddin, Uceu F. H.; Cardillo, Maria E. B.; dos Santos, Jorge F.

    2014-05-01

    A dissimilar joint of AA5083 Al alloy and copper was produced by friction spot welding. The Al-MgCuAl2 eutectic in both coupled and divorced manners were found in the weld. At a relatively high temperature, mass transport of Cu due to plastic deformation, material flow, and atomic diffusion, combined with the alloy system of AA5083 are responsible for the ternary eutectic melting.

  7. Localized silicon fusion and eutectic bonding for MEMS fabrication and packaging

    Microsoft Academic Search

    Y. T. Cheng; Liwei Lin; Khalil Najafi

    2000-01-01

    Silicon fusion and eutectic bonding processes based on the technique of localized heating have been successfully demonstrated. Phosphorus-doped polysilicon and gold films are applied separately in the silicon-to-glass fusion bonding and silicon-to-gold eutectic bonding experiments. These films are patterned as line-shape resistive heaters with widths of 5 or 7 ?m for the purpose of heating and bonding. In the experiments,

  8. On the properties of the eutectic alloy Al 3(Nb,Cr) + Cr(Al,Nb)

    Microsoft Academic Search

    S. A. Souza; P. L. Ferrandini; E. A. Souza; A. O. dos Santos; R. Caram

    2008-01-01

    The eutectic alloy Al3(Nb,Cr)+Cr(Al,Nb) forms an in situ composite and the Al3Nb presents high specific strength and low oxidation rate that may be improved by the combination with other phases. The purpose of this work is to investigate physical, mechanical and oxidation properties of the eutectic alloy. Therefore, Rietveld analysis was carried out for furnace cooled and water quenched samples

  9. Directional solidification and characterization of the Cd–Sn eutectic alloy

    Microsoft Academic Search

    E. Çad?rl?; H. Kaya; M. Gündüz

    2007-01-01

    The Cd–67.8wt.% Sn eutectic alloy was prepared by melting together appropriate amounts of cadmium and tin (both of 99.99% purity) in a graphite crucible in a vacuum melting furnace. Then, this eutectic alloy was poured into graphite crucibles in a hot filling furnace and the samples were solidified. These samples were directionally solidified upward with different growth rate ranges (8.1–165?m\\/s)

  10. Microstructures from a directionally solidified NiAl-Cr eutectic deformed at room temperature

    SciTech Connect

    Chen, X.F.; Johnson, D.R.; Oliver, B.F. (Univ. of Tennessee, Knoxville, TN (United States). Material Science and Engineering Dept.)

    1994-04-15

    Directionally solidified alloys based on the NiAl-Cr eutectic have shown promise as high temperature structural materials. This eutectic is characterized by a fibrous microstructure consisting of chromium rods embedded within a NiAl matrix. The reinforcing metal phase provides improvements in the elevated temperature strength and the room temperature fracture toughness of the NiAl matrix. The fracture toughness of the NiAl-Cr eutectic is much greater than that of NiAl. The directionally solidified NiAl-Cr eutectic has a fracture toughness of approximately 18--21 MPa[radical]m while polycrystalline NiAl has a fracture toughness of 6 MPa[radical]m. Single crystals of NiAl oriented with a [001] notch plane have a fracture toughness of 8 MPa[radical]m. Recently, the fracture resistance of fibrous NiAl-refractory metal eutectics has been described by crack trapping and crack bridging mechanisms. However, mechanical property data for NiAl-Cr eutectic are sparse, especially those generated at room temperature. Typically, the fracture behavior is characterized by scanning electron microscopy (SEM) and optical microscopy. To complement these existing data, observations of the deformation and fracture behavior by transmission electron microscopy (TEM) are reported here.

  11. Gravity-induced anomalies in interphase spacing reported for binary eutectics.

    PubMed

    Smith, Reginald W

    2002-10-01

    It has been reasoned that desirable microstructural refinement in binary eutectics could result from freezing in reduced-gravity. It is recognized that the interphase spacing in a binary eutectic is controlled by solute transport and that, on Earth, buoyancy-driven convection may enhance this. Hence, it has been presumed that the interphase spacing ought to decrease when a eutectic alloy is frozen under conditions of much-reduced gravity, where such buoyancy effects would be largely absent. The result of such speculation has been that many workers have frozen various eutectics under reduced gravity and have reported that, although some eutectics became finer, others showed no change, and some even became coarser. This reported varied behavior will be reviewed in the light of long term studies by the author at Queen's University, including recent microgravity studies in which samples of two eutectic alloy systems, MnBi-Bi and MnSb-Sb, were frozen under very stable conditions and showed no change in interphase spacing. PMID:12446324

  12. Thermal storage in ammonium alum/ammonium nitrate eutectic for solar space heating applications

    SciTech Connect

    Jotshi, C.K.; Hsieh, C.K.; Goswami, D.Y.; Klausner, J.F.; Srinivasan, N. [Univ. of Florida, Gainesville, FL (United States). Dept. of Mechanical Engineering

    1998-02-01

    Ammonium alum and ammonium nitrate in the weight ratio of 1:1 form a eutectic that melts at 53 C and solidifies at 48 C. The thermophysical properties of this eutectic were measured in detail and the eutectic was found to have properties desirable for energy storage for solar space heating applications. The eutectic was encapsulated in 0.0254-m diameter high-density polyethylene (HDPE) balls and packed into a cylindrical bed in a scale model for testing its heat transfer characteristics when exposed to an air flow. Test results indicate that the thermal extraction efficiency of the model was 89% with an uncertainty of {+-} 8.0%. The packed bed had a Stanton number value in close agreement with that predicted with an empirical equation for sensible heat extraction from the eutectic in the solid phase. This Stanton number was increased by about 74% for sensible heat extraction from the eutectic in the liquid phase, a phenomenon not previously reported in the literature.

  13. Directionally solidified pseudo-binary eutectics of Ni-Cr-(Hf, Zr)

    NASA Technical Reports Server (NTRS)

    Kim, Y. G.; Ashbrook, R. L.

    1975-01-01

    A pseudo-binary eutectic, in which the intermetallic Ni7Hf2 reinforces the Ni-Cr solid solution phase, was previously predicted in the Ni-Cr-Hf system by a computer analysis. The experimental determination of pseudo binary eutectic compositions and the directional solidification of the Ni-Cr-Hf, Zr, and Ni-Cr-Zr eutectic alloys are discussed. To determine unknown eutectics, chemical analyses were made of material bled from near eutectic ingots during incipient melting. Nominal compositions in weight percent of Ni-18.6Cr-24.0HF, Ni19.6Cr-12.8Zr-2.8Hf, and Ni-19.2Cr-14.8Zr formed aligned pseudo-binary eutectic structures. The melting points were about 1270 C. The reinforcing intermetallic phases were identified as noncubic (Ni,Cr)7Hf2 and (Ni,Cr)7(Hf,Zr)2, and face centered cubic (Ni,Cr)5Zr. The volume fraction of the reinforcing phases were about 0.5.

  14. Formation mechanism of primary phases and eutectic structures within undercooled Pb-Sb-Sn ternary alloys

    NASA Astrophysics Data System (ADS)

    Wang, Weili; Dai, Fuping; Wei, Bingbo

    2007-08-01

    The solidification characteristics of three types of Pb-Sb-Sn ternary alloys with different primary phases were studied under substantial undercooling conditions. The experimental results show that primary (Pb) and SbSn phases grow in the dendritic mode, whereas primary (Sb) phase exhibits faceted growth in the form of polygonal blocks and long strips. (Pb) solid solution phase displays strong affinity with SbSn intermetallic compound so that they produce various morphologies of pseudobinary eutectics, but it can only grow in the divorced eutectic mode together with (Sb) phase. Although (Sb) solid solution phase and SbSn intermetallic compound may grow cooperatively within ternary eutectic microstructures, they seldom form pseudobinary eutectics independently. The (Pb)+(Sb)+SbSn ternary eutectic structure usually shows lamellar morphology, but appears as anomalous eutectic when its volume fraction becomes small. EDS analyses reveal that all of the three primary (Pb), (Sb) and SbSn phases exhibit conspicuous solute trapping effect during rapid solidification, which results in the remarkable extension of solute solubility.

  15. Fractal characteristic of laser zone remelted Al 2O 3/YAG eutectic in situ composite

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Su, Haijun; Tang, Bo; Liu, Lin; Fu, Hengzhi

    2008-01-01

    Directionally solidified alumina-based eutectic in situ composite has complex, irregular and self-similar microstructure composed of two or more phases to form three dimensionally interpenetrating network as "Chinese Script" type structure. In this paper, the fractal analysis is applied to Al 2O 3/Y 3Al 5O 12 (YAG) eutectic in situ composite prepared by laser zone remelting in order to quantitatively characterize the microstructure morphology and mechanical property. The fractal dimension of the eutectic microstructure is determined by the box counting technique according to the scanning electron microscope micrograph. The relationships between the fractal dimension and the laser processing parameter, eutectic spacing, and mechanical properties are studied. The results indicate that the eutectic morphology of Al 2O 3/YAG in situ composite has typical fractal characteristic. The fractal dimension changes from 1.61 to 1.82 when the laser-scanning rate increases from 10 to 400 ?m/s. With the increase of the fractal dimension, the eutectic spacing decreases while the hardness and the fracture toughness all increase.

  16. Viscosity of multi-component molten nitrate salts : liquidus to 200 degrees C.

    SciTech Connect

    Bradshaw, Robert W.

    2010-03-01

    The viscosity of molten salts comprising ternary and quaternary mixtures of the nitrates of sodium, potassium, lithium and calcium was determined experimentally. Viscosity was measured over the temperature range from near the relatively low liquidus temperatures of he individual mixtures to 200C. Molten salt mixtures that do not contain calcium nitrate exhibited relatively low viscosity and an Arrhenius temperature dependence. Molten salt mixtures that contained calcium nitrate were relatively more viscous and viscosity increased as the roportion of calcium nitrate increased. The temperature dependence of viscosity of molten salts containing calcium nitrate displayed curvature, rather than linearity, when plotted in Arrhenius format. Viscosity data for these mixtures were correlated by the Vogel-Fulcher- ammann-Hesse equation.

  17. Density relaxation and particle motion characteristics in a non-ionic deep eutectic solvent (acetamide + urea): time-resolved fluorescence measurements and all-atom molecular dynamics simulations.

    PubMed

    Das, Anuradha; Das, Suman; Biswas, Ranjit

    2015-01-21

    Temperature dependent relaxation dynamics, particle motion characteristics, and heterogeneity aspects of deep eutectic solvents (DESs) made of acetamide (CH3CONH2) and urea (NH2CONH2) have been investigated by employing time-resolved fluorescence measurements and all-atom molecular dynamics simulations. Three different compositions (f) for the mixture [fCH3CONH2 + (1 - f)NH2CONH2] have been studied in a temperature range of 328-353 K which is ?120-145 K above the measured glass transition temperatures (?207 K) of these DESs but much lower than the individual melting temperature of either of the constituents. Steady state fluorescence emission measurements using probe solutes with sharply different lifetimes do not indicate any dependence on excitation wavelength in these metastable molten systems. Time-resolved fluorescence anisotropy measurements reveal near-hydrodynamic coupling between medium viscosity and rotation of a dissolved dipolar solute. Stokes shift dynamics have been found to be too fast to be detected by the time-resolution (?70 ps) employed, suggesting extremely rapid medium polarization relaxation. All-atom simulations reveal Gaussian distribution for particle displacements and van Hove correlations, and significant overlap between non-Gaussian (?2) and new non-Gaussian (?) heterogeneity parameters. In addition, no stretched exponential relaxations have been detected in the simulated wavenumber dependent acetamide dynamic structure factors. All these results are in sharp contrast to earlier observations for ionic deep eutectics with acetamide [Guchhait et al., J. Chem. Phys. 140, 104514 (2014)] and suggest a fundamental difference in interaction and dynamics between ionic and non-ionic deep eutectic solvent systems. PMID:25612718

  18. Density relaxation and particle motion characteristics in a non-ionic deep eutectic solvent (acetamide + urea): Time-resolved fluorescence measurements and all-atom molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Das, Anuradha; Das, Suman; Biswas, Ranjit

    2015-01-01

    Temperature dependent relaxation dynamics, particle motion characteristics, and heterogeneity aspects of deep eutectic solvents (DESs) made of acetamide (CH3CONH2) and urea (NH2CONH2) have been investigated by employing time-resolved fluorescence measurements and all-atom molecular dynamics simulations. Three different compositions (f) for the mixture [fCH3CONH2 + (1 - f)NH2CONH2] have been studied in a temperature range of 328-353 K which is ˜120-145 K above the measured glass transition temperatures (˜207 K) of these DESs but much lower than the individual melting temperature of either of the constituents. Steady state fluorescence emission measurements using probe solutes with sharply different lifetimes do not indicate any dependence on excitation wavelength in these metastable molten systems. Time-resolved fluorescence anisotropy measurements reveal near-hydrodynamic coupling between medium viscosity and rotation of a dissolved dipolar solute. Stokes shift dynamics have been found to be too fast to be detected by the time-resolution (˜70 ps) employed, suggesting extremely rapid medium polarization relaxation. All-atom simulations reveal Gaussian distribution for particle displacements and van Hove correlations, and significant overlap between non-Gaussian (?2) and new non-Gaussian (?) heterogeneity parameters. In addition, no stretched exponential relaxations have been detected in the simulated wavenumber dependent acetamide dynamic structure factors. All these results are in sharp contrast to earlier observations for ionic deep eutectics with acetamide [Guchhait et al., J. Chem. Phys. 140, 104514 (2014)] and suggest a fundamental difference in interaction and dynamics between ionic and non-ionic deep eutectic solvent systems.

  19. Salt tectonics on Venus

    SciTech Connect

    Wood, C.A.; Amsbury, D.

    1986-05-01

    The discovery of a surprisingly high deuterium/hydrogen ratio on Venus immediately led to the speculation that Venus may have once had a volume of surface water comparable to that of the terrestrial oceans. The authors propose that the evaporation of this putative ocean may have yielded residual salt deposits that formed various terrain features depicted in Venera 15 and 16 radar images. By analogy with models for the total evaporation of the terrestrial oceans, evaporite deposits on Venus should be at least tens to hundreds of meters thick. From photogeologic evidence and in-situ chemical analyses, it appears that the salt plains were later buried by lava flows. On Earth, salt diapirism leads to the formation of salt domes, anticlines, and elongated salt intrusions - features having dimensions of roughly 1 to 100 km. Due to the rapid erosion of salt by water, surface evaporite landforms are only common in dry regions such as the Zagros Mountains of Iran, where salt plugs and glaciers exist. Venus is far drier than Iran; extruded salt should be preserved, although the high surface temperature (470/sup 0/C) would probably stimulate rapid salt flow. Venus possesses a variety of circular landforms, tens to hundreds of kilometers wide, which could be either megasalt domes or salt intrusions colonizing impact craters. Additionally, arcurate bands seen in the Maxwell area of Venus could be salt intrusions formed in a region of tectonic stress. These large structures may not be salt features; nonetheless, salt features should exist on Venus.

  20. Prussian blue nanospheres synthesized in deep eutectic solvents

    NASA Astrophysics Data System (ADS)

    Sheng, Qinglin; Liu, Ruixiao; Zheng, Jianbin

    2012-10-01

    A novel route for controlled synthesis of Prussian blue nanospheres (PB NSs) with different sizes by using deep eutectic solvents (DES) as both solvent and template provider was demonstrated. The size-controlled PB NSs were obtained directly by the coordination of Fe(CN)64- ion with Fe3+ ion in the DES. The probable mechanism of formation of PB NSs was discussed based on the characterization results of UV-visible, X-ray diffraction, X-ray photoelectronic spectrum and transfer electron microscopy. Furthermore, the electrochemical and electrocatalytic properties of the synthesized PB NSs were investigated, and it has demonstrated that the PB NSs exhibited excellent catalytic activity for H2O2 reduction, and then extended this strategy to glucose sensing, by detecting H2O2 formed from the enzymatic reaction of glucose oxidase with its substrate glucose. The linear calibration range for glucose was from 0.9 ?M to 0.12 mM, with a correlation coefficient of 0.998. The limit of detection was 0.3 ?M and the sensitivity was 61.7 A cm-2 M-1. The present study provides a general platform for the controlled synthesis of novel nanomaterials in DES and can be extended to other optical, electronic and magnetic nanocompounds.A novel route for controlled synthesis of Prussian blue nanospheres (PB NSs) with different sizes by using deep eutectic solvents (DES) as both solvent and template provider was demonstrated. The size-controlled PB NSs were obtained directly by the coordination of Fe(CN)64- ion with Fe3+ ion in the DES. The probable mechanism of formation of PB NSs was discussed based on the characterization results of UV-visible, X-ray diffraction, X-ray photoelectronic spectrum and transfer electron microscopy. Furthermore, the electrochemical and electrocatalytic properties of the synthesized PB NSs were investigated, and it has demonstrated that the PB NSs exhibited excellent catalytic activity for H2O2 reduction, and then extended this strategy to glucose sensing, by detecting H2O2 formed from the enzymatic reaction of glucose oxidase with its substrate glucose. The linear calibration range for glucose was from 0.9 ?M to 0.12 mM, with a correlation coefficient of 0.998. The limit of detection was 0.3 ?M and the sensitivity was 61.7 A cm-2 M-1. The present study provides a general platform for the controlled synthesis of novel nanomaterials in DES and can be extended to other optical, electronic and magnetic nanocompounds. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr31830j

  1. Utah: Salt Lake Region

    Atmospheric Science Data Center

    2014-05-15

    article title:  Winter and Summer Views of the Salt Lake Region     View Larger Image Magnificent views of the region surrounding Salt Lake City, Utah are captured in these winter and summer images from the ...

  2. Molten salt electrolyte separator

    DOEpatents

    Kaun, Thomas D. (New Lenox, IL)

    1996-01-01

    A molten salt electrolyte/separator for battery and related electrochemical systems including a molten electrolyte composition and an electrically insulating solid salt dispersed therein, to provide improved performance at higher current densities and alternate designs through ease of fabrication.

  3. Water uptake by salts during the electrolyte processing for thermal batteries

    NASA Astrophysics Data System (ADS)

    Masset, Patrick; Poinso, Jean-Yves; Poignet, Jean-Claude

    Water uptake of single salts and electrolytes were measured in industrial conditions (dry-room). The water uptake rate ? (g h -1 cm -2) was expressed with respect to the apparent area of contact of the salt with atmosphere of the dry room. The water uptake by potassium-based salts was very low. LiF and LiCl salts were found to behave similarly. For LiBr- and LiI-based salts and mixtures, we pointed out a linear relationship between the water uptake and the elapsed time. Water uptake by magnesium oxide reached a limit after 200 h. This work provides a set of data concerning the rate of water uptake by single salts, salt mixtures and magnesia used in thermal battery electrolytes.

  4. Directional solidification of Al2-Cu-Al and Al3-Ni-Al eutectics during TEXUS rocket flight

    NASA Technical Reports Server (NTRS)

    Favier, J. J.; Degoer, J.

    1984-01-01

    One lamellar eutectic sample and one fiber-like eutectic sample were solidified directionally during the TEXUS-6 rocket flight. The microstructures and the results of the thermal analysis, obtained from the temperatures recorded on the cartridge skin, are compared. No appreciable modifications of the regularity of the eutectic structures were observed by passing from 1 g to 0.0001 g in these experiments. No steady state growth conditions were achieved in these experiments.

  5. The melting points of binary mixtures of oleic, linoleic, and linolenic acids

    Microsoft Academic Search

    H. W. Stewart; D. H. Wheeler

    1941-01-01

    Summary  1. The melting points of binary mixtures of oleic, linoleic, and linolenic acids have been reported.\\u000a \\u000a 2. The oleic-linoleic acid system has eutectics for the ? and ? forms of oleic acid of 75.2 and 76.3 mole per cent linoleic\\u000a acid, at ?10.0° and ?9.8°, respectively.\\u000a \\u000a \\u000a \\u000a 3. Linoleic and linolenic acid mixtures show only melting points intermediate between the pure

  6. Plant salt tolerance

    Microsoft Academic Search

    Jian-Kang Zhu

    2001-01-01

    Soil salinity is a major abiotic stress in plant agriculture worldwide. This has led to research into salt tolerance with the aim of improving crop plants. However, salt tolerance might have much wider implications because transgenic salt-tolerant plants often also tolerate other stresses including chilling, freezing, heat and drought. Unfortunately, suitable genetic model systems have been hard to find. A

  7. Shaking the Salt Habit

    MedlinePLUS

    ... Don't salt food before you taste it; enjoy the natural taste of food. Take the salt shaker off the table. Adding more salt at the table adds to your daily sodium intake without adding much to the flavor of your food. Eat less ...

  8. Plant salt tolerance

    Microsoft Academic Search

    Viswanathan Chinnusamy; Jian-Kang Zhu

    Soil salinity adversely affects crop productivity and quality. The success of breeding programs aimed at salinity tolerant crop varieties is limited by the lack of a clear understanding of the molecular basis of salt tolerance. Recent advances in genetic analysis of Arabidopsis mutants defective in salt tolerance, and molecular cloning of these loci, have showed some insight into salt stress

  9. Prussian blue nanospheres synthesized in deep eutectic solvents.

    PubMed

    Sheng, Qinglin; Liu, Ruixiao; Zheng, Jianbin

    2012-11-01

    A novel route for controlled synthesis of Prussian blue nanospheres (PB NSs) with different sizes by using deep eutectic solvents (DES) as both solvent and template provider was demonstrated. The size-controlled PB NSs were obtained directly by the coordination of Fe(CN)(6)(4-) ion with Fe(3+) ion in the DES. The probable mechanism of formation of PB NSs was discussed based on the characterization results of UV-visible, X-ray diffraction, X-ray photoelectronic spectrum and transfer electron microscopy. Furthermore, the electrochemical and electrocatalytic properties of the synthesized PB NSs were investigated, and it has demonstrated that the PB NSs exhibited excellent catalytic activity for H(2)O(2) reduction, and then extended this strategy to glucose sensing, by detecting H(2)O(2) formed from the enzymatic reaction of glucose oxidase with its substrate glucose. The linear calibration range for glucose was from 0.9 ?M to 0.12 mM, with a correlation coefficient of 0.998. The limit of detection was 0.3 ?M and the sensitivity was 61.7 A cm(-2) M(-1). The present study provides a general platform for the controlled synthesis of novel nanomaterials in DES and can be extended to other optical, electronic and magnetic nanocompounds. PMID:23034657

  10. Interphase anisotropy effects on lamellar eutectics: a numerical study.

    PubMed

    Ghosh, Supriyo; Choudhury, Abhik; Plapp, Mathis; Bottin-Rousseau, Sabine; Faivre, Gabriel; Akamatsu, Silvère

    2015-02-01

    In directional solidification of binary eutectics, it is often observed that two-phase lamellar growth patterns grow tilted with respect to the direction z of the imposed temperature gradient. This crystallographic effect depends on the orientation of the two crystal phases ? and ? with respect to z. Recently, an approximate theory was formulated that predicts the lamellar tilt angle as a function of the anisotropy of the free energy of the solid(?)-solid(?) interphase boundary. We use two different numerical methods-phase field (PF) and dynamic boundary integral (BI)-to simulate the growth of steady periodic patterns in two dimensions as a function of the angle ?(R) between z and a reference crystallographic axis for a fixed relative orientation of ? and ? crystals, that is, for a given anisotropy function (Wulff plot) of the interphase boundary. For Wulff plots without unstable interphase-boundary orientations, the two simulation methods are in excellent agreement with each other and confirm the general validity of the previously proposed theory. In addition, a crystallographic "locking" of the lamellae onto a facet plane is well reproduced in the simulations. When unstable orientations are present in the Wulff plot, it is expected that two distinct values of the tilt angle can appear for the same crystal orientation over a finite ?(R) range. This bistable behavior, which has been observed experimentally, is well reproduced by BI simulations but not by the PF model. Possible reasons for this discrepancy are discussed. PMID:25768518

  11. Injector nozzle for molten salt destruction of energetic waste materials

    DOEpatents

    Brummond, William A. (Livermore, CA); Upadhye, Ravindra S. (Pleasanton, CA)

    1996-01-01

    An injector nozzle has been designed for safely injecting energetic waste materials, such as high explosives, propellants, and rocket fuels, into a molten salt reactor in a molten salt destruction process without premature detonation or back burn in the injection system. The energetic waste material is typically diluted to form a fluid fuel mixture that is injected rapidly into the reactor. A carrier gas used in the nozzle serves as a carrier for the fuel mixture, and further dilutes the energetic material and increases its injection velocity into the reactor. The injector nozzle is cooled to keep the fuel mixture below the decomposition temperature to prevent spontaneous detonation of the explosive materials before contact with the high-temperature molten salt bath.

  12. The effect of porosity and gamma-gamma-prime eutectic content on the fatigue behavior of hydrogen charged PWA 1480

    NASA Technical Reports Server (NTRS)

    Gayda, J.; Dreshfield, R. L.; Gabb, T. P.

    1991-01-01

    The study addresses the effect of systematically varying gamma-gamma-prime eutectic content and porosity level on the fatigue life of a hydrogen-charged single crystal PWA 1480 superalloy. Four microstructural variants are produced, and differences in gamma-gamma-prime eutectic morphology among the four processing variants are analyzed. Single valued tensile test data indicate that the tensile and yield strength of the PWA 1480 are degraded by hydrogen charging, with the exception of the material given a eutectic solution treatment. It is shown that the reduction of the fatigue life can be minimized by a duplex thermomechanical treatment consisting of a eutectic solution followed by hot isostatic pressing.

  13. Simultaneous extraction of flavonoids from Chamaecyparis obtusa using deep eutectic solvents as additives of conventional extractions solvents.

    PubMed

    Tang, Baokun; Park, Ha Eun; Row, Kyung Ho

    2015-01-01

    Three flavones (quercetin, myricetin and amentoflavone) were extracted from Chamaecyparis obtusa leaves using deep eutectic solvents (DESs) as additives to conventional extractions solvents. Sixteen DESs were synthesized from different salts and hydrogen bond donors. In addition, C. obtusa was extracted under optimal conditions of methanol as the solvent in the heating process (60°C) for 120 min at a solid/liquid ratio of 80%. Under these optimal conditions, a good linear relationship was observed at analyte concentrations ranging from 5.0 to 200.0 ?g/mL (R(2) > 0.999). The extraction recovery ranged from 96.7 to 103.3% with the inter- and intraday relative standard deviations of <4.97%. Under the optimal conditions, from C. obtusa, the quantities of quercetin, myricetin and amentoflavone extracted were 325.90, 8.66 and 50.34 µg/mL, respectively. Overall, DESs are expected to have a wide range of applications. PMID:25228687

  14. Ionic liquid and deep eutectic solvent-activated CelA2 variants generated by directed evolution.

    PubMed

    Lehmann, Christian; Bocola, Marco; Streit, Wolfgang R; Martinez, Ronny; Schwaneberg, Ulrich

    2014-06-01

    Chemoenzymatic cellulose degradation is one of the key steps for the production of biomass-based fuels under mild conditions. An effective cellulose degradation process requires diverse physico-chemical dissolution of the biomass prior to enzymatic degradation. In recent years, "green" solvents, such as ionic liquids and, more recently, deep eutectic liquids, have been proposed as suitable alternatives for biomass dissolution by homogenous catalysis. In this manuscript, a directed evolution campaign of an ionic liquid tolerant ?-1,4-endoglucanase (CelA2) was performed in order to increase its performance in the presence of choline chloride/glycerol (ChCl:Gly) or 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), as a first step to identify residues which govern ionic strength resistance and obtaining insights for employing cellulases on the long run in homogenous catalysis of lignocellulose degradation. After mutant library screening, variant M4 (His288Phe, Ser300Arg) was identified, showing a dramatically reduced activity in potassium phosphate buffer and an increased activity in the presence of ChCl:Gly or [BMIM]Cl. Further characterization showed that the CelA2 variant M4 is activated in the presence of these solvents, representing a first report of an engineered enzyme with an ionic strength activity switch. Structural analysis revealed that Arg300 could be a key residue for the ionic strength activation through a salt bridge with the neighboring Asp287. Experimental and computational results suggest that the salt bridge Asp287-Arg300 generates a nearly inactive CelA2 variant and activity is regained when ChCl:Gly or [BMIM]Cl are supplemented (~5-fold increase from 0.64 to 3.37 ?M 4-MU/h with the addition ChCl:Gly and ~23-fold increase from 3.84 to 89.21 ?M 4-pNP/h with the addition of [BMIM]Cl). Molecular dynamic simulations further suggest that the salt bridge between Asp287 and Arg300 in variant M4 (His288Phe, Ser300Arg) modulates the observed salt activation. PMID:24802079

  15. Salt tolerance of common green roof and green wall plants

    Microsoft Academic Search

    Leigh J. Whittinghill; D. Bradley Rowe

    Detrimental effects of road deicing salt on vegetation are well known and have been well studied, with the exception of typical\\u000a green roof plants, which could experience damage on green roofs with public access and green walls near roadways in cold climates.\\u000a Two studies were conducted comparing salt tolerance of five Sedum species, two Allium species and a mixture of

  16. A quantitative study of factors influencing lamellar eutectic morphology during solidification

    NASA Technical Reports Server (NTRS)

    Kaukler, W. F. S.

    1981-01-01

    The factors that influence the shape of the solid-liquid interface of a lamellar binary eutectic alloy are evaluated. Alloys of carbon tetrabromide and hexachloroethane which serve as a transparent analogue of lamellar metallic eutectics are used. The observed interface shapes are analyzed by computer-aided methods. The solid-liquid interfacial free energies of each of the individual phases comprising the eutectic system are measured as a function of composition using a 'grain boundary groove' technique. The solid-liquid interfacial free energy of the two phases are evaluated directly from the eutectic interface. The phase diagram for the system, the heat of fusion as a function of composition, and the density as a function of composition are measured. The shape of the eutectic interface is controlled mainly by the solid-liquid and solid-solid interfacial free energy relationships at the interface and by the temperature gradient present, rather than by interlamellar diffusion in the liquid at the interface, over the range of growth rates studied.

  17. Deformation and fracture of a directionally solidified NiAl-28Cr-6Mo eutectic alloy

    NASA Technical Reports Server (NTRS)

    Chen, X. F.; Johnson, D. R.; Noebe, R. D.; Oliver, B. F.

    1995-01-01

    A directionally solidified alloy based on the NiAl-(Cr, Mo) eutectic was examined by transmission and scanning electron microscopy to characterize the microstructure and room temperature deformation and fracture behavior. The microstructure consisted of a lamellar morphology with a group of zone axes (111) growth direction for both the NiAl and (Cr, Mo) phases. The interphase boundary between the eutectic phases was semicoherent and composed of a well-defined dislocation network. In addition, a fine array of coherent NiAl precipitates was dispersed throughout the (Cr, Mo) phase. The eutectic morphology was stable at 1300 K with only coarsening of the NiAl precipitates occurring after heat treatment for 1.8 ks (500 h). Fracture of the aligned eutectic is characterized primarily by a crack bridging/renucleation mechanism and is controlled by the strength of the semicoherent interface between the two phases. However, contributions to the toughness of the eutectic may arise from plastic deformation of the NiAl phase and the geometry associated with the fracture surface.

  18. Deformation and fracture of a directionally solidified NiAl-28Cr-6Mo eutectic alloy

    SciTech Connect

    Chen, X.F.; Johnson, D.R.; Noebe, R.D.; Oliver, B.F.

    1995-05-01

    A directionally solidified alloy based on the NiAl-(Cr, Mo) eutectic was examined by transmission and scanning electron microscopy to characterize the microstructure and room temperature deformation and fracture behavior. The microstructure consisted of a lamellar morphology with a group of zone axes (111) growth direction for both the NiAl and (Cr, Mo) phases. The interphase boundary between the eutectic phases was semicoherent and composed of a well-defined dislocation network. In addition, a fine array of coherent NiAl precipitates was dispersed throughout the (Cr, Mo) phase. The eutectic morphology was stable at 1300 K with only coarsening of the NiAl precipitates occurring after heat treatment for 1.8 ks (500 h). Fracture of the aligned eutectic is characterized primarily by a crack bridging/renucleation mechanism and is controlled by the strength of the semicoherent interface between the two phases. However, contributions to the toughness of the eutectic may arise from plastic deformation of the NiAl phase and the geometry associated with the fracture surface.

  19. Melts microheterogeneity in binary metallic systems having eutectic and monotectic transformations

    NASA Astrophysics Data System (ADS)

    Zhukova, L. A.; Aksyonova, O. P.; Zhukov, A. A.

    2008-02-01

    The distinctive features of limited solubility in liquid eutectic and monotectic metallic systems have been discovered. The monodispersed emulsion model has been elaborated for a description of the specific microheterogeneous structure of eutectic melts. It includes the transitional shells (TS) at the interface boundaries having the eutectic composition and the closest packing of atoms. By means of the thermodynamic analysis a possibility of a metastable equilibrium of the emulsion has been determined when dimensional and interface energy parameters of the emulsion adopt certain values. The metastable state is characterized by the colloidal sizes of disperse particles and the interface tension values typical for immiscible melts. The existence of the emulsion has been confirmed by the calorimetric experimental data on Sn-Pb and Al-Si systems. Structure factors and RDF's of the TS have been calculated by the original treatment of experimental diffraction data on Sn-Pb and Ag-Ge melts. The evidence of different microheterogeneity scales in liquid eutectic and monotectic systems has been obtained. From two immiscible phases only the liquid based on the light-melted metal shows the short-range microinhomogeneity and the second one is a homogeneous solution. So, the microheterogeneity in eutectic and monotectic melts has different nature.

  20. PU/SS EUTECTIC ASSESSMENT IN 9975 PACKAGINGS IN A STORAGE FACILITY DURING EXTENDED FIRE

    SciTech Connect

    Gupta, N.

    2012-03-26

    In a radioactive material (RAM) packaging, the formation of eutectic at the Pu/SS (plutonium/stainless steel) interface is a serious concern and must be avoided to prevent of leakage of fissile material to the environment. The eutectic temperature for the Pu/SS is rather low (410 C) and could seriously impact the structural integrity of the containment vessel under accident conditions involving fire. The 9975 packaging is used for long term storage of Pu bearing materials in the DOE complex where the Pu comes in contact with the stainless steel containment vessel. Due to the serious consequences of the containment breach at the eutectic site, the Pu/SS interface temperature is kept well below the eutectic formation temperature of 410 C. This paper discusses the thermal models and the results for the extended fire conditions (1500 F for 86 minutes) that exist in a long term storage facility and concludes that the 9975 packaging Pu/SS interface temperature is well below the eutectic temperature.

  1. Thermal storage device

    SciTech Connect

    Schroder, J.

    1982-04-13

    The increase in volume of a heat storage medium comprising water or a first eutectic mixture of water and a salt hydrate, when such storage medium passes from the liquid to the solid state, is prevented from occurring by adding 1 to 6% by volume of a second water-salt hydrate eutectic having a lower freezing point to the storage medium.

  2. digestive mixture by 2H NMR

    Microsoft Academic Search

    Philip W. Westerman

    H nuclear magnetic resonance (NMR) spectra were obtained at 30.87 MHz for 8% (w\\/v) aqueous disper- sions of mixtures of bile salts (MBS), mixed intestinal lipids (MIL; myristic acid, monomyristoylglycerol, dimyristoylphos- phatidylcholine = 5:1:1), and cholesterol, in which a single lipid component is selectively 2H-labeled. Using the observa- tion that the time-averaged quadrupole splitting of a C2H3 group varies according

  3. The Effect of Silica Nanoparticles on Corrosion of Steel by Molten Carbonate Eutectics 

    E-print Network

    Padmanaban Iyer, Ashwin

    2011-08-08

    a base salt or the nano-composite salt. 3) Salts were prepared using the aqueous method. Salt (Base salt +Nanoparticle) was first dissolved in water. It was then subject to rapid evaporation, ensuring a nice fine fry powder at the end....2 Experimental Process/Methods .............................................................................. 28 3.2.1 Material Preparation ......................................................................................... 29 3.2.2 Sample Bomb and Frame...

  4. Metal-halide mixtures for latent heat energy storage

    NASA Technical Reports Server (NTRS)

    Chen, K.; Manvi, R.

    1981-01-01

    Some candidates for alkali metal and alkali halide mixtures suitable for thermal energy storage at temperatures 600 C are identified. A solar thermal system application which offer advantages such as precipitation of salt crystals away from heat transfer surfaces, increased thermal conductivity of phase change materials, corrosion inhibition, and a constant monotectic temperature, independent of mixture concentrations. By using the lighters, metal rich phase as a heat transfer medium and the denser, salt rich phase as a phase change material for latent heat storage, undesirable solidification on the heat transfer surface may be prevented, is presented.

  5. Influence of microgravity on solidification behavior of Al-Al3Ni eutectic alloy

    NASA Astrophysics Data System (ADS)

    Huang, Q.; Luo, X.-H.; Li, Y.-Y.

    Directional solidification experiments of Al-Al 3 Ni eutectic alloy were performed in the Multi-functional Crystal Growing Furnace on board the unmanned Chinese Shenzhou spacecraft and in the laboratory on earth respectively to compare their solidification behavior under microgravity and normal gravity conditions The specimens gained were investigated using metallographic SEM XRD and Image analysis techniques Many significant differences both macroscopic and microscopic were observed between the specimens solidified in space and on the earth Especially the mean inter-fiber spacing and spacing distribution range obtained under microgravity were found larger than those obtained under normal gravity An off-eutectic theory was tried to explain those differences and achieved a good agreement In combination with the analyses on reported experimental results in other works it could be deduced that the change of inter-fibre spacing of eutectic alloy with microgravity is determined by the alloy system

  6. Magnetic properties of directionally solidified MnSb/Sb eutectic composite

    SciTech Connect

    Pan, Y.; Sun, G. [Southeast Univ., Nanjing (China). Dept. of Mechanical Engineering] [Southeast Univ., Nanjing (China). Dept. of Mechanical Engineering

    1999-09-10

    MnSb is the only ferromagnetic compound in the first-row transition-metal antimonides; it is highly anisotropic and proposed to be an important magnetic material for a variety of potential applications. The controlled eutectics consisting of MnSb and other components may constitute functional in-situ composites without any contamination and wetting problem between the components because of multiphase cooperative growth. The anisotropic MnSb/Sb composite is expected to possess interesting magnetic properties if MnSb is embedded in a diamagnetic antimony matrix as regular eutectic by directional solidification. However, very little has been published on MnSb/Sb eutectic composites. In the composite, the shape, size, orientation and distribution of magnetic components are important parameters which determine the quality of the materials. Consideration of these factors leads to the investigation on the relationships between microstructure, magnetic property and temperature dependence of the property in this system.

  7. One-Pot Multi-component Synthesis of 1,4-Dihydropyridine Derivatives in Biocompatible Deep Eutectic Solvents

    E-print Network

    Pednekar, Suhas; Ghadge, Nitin

    2013-01-01

    An efficient protocol for the synthesis of differently substituted 1, 4-dihydropyridines in deep eutectic solvents under solvent-free conditions is reported herewith. Excellent yields of the resultant products have been obtained. Recyclability studies have also been performed for deep eutectic solvents with very little loss in activity up to five recycles.

  8. Revised form of Jackson–Hunt theory: application to directional solidification of MnBi\\/Bi eutectics

    Microsoft Academic Search

    L. L Zheng; D. J Larson Jr; H Zhang

    2000-01-01

    A generalized eutectic theory, which defaults to the prior theories by Jackson–Hunt and Trivedi et al. under their boundary conditions, has been developed to consider phase relations, solidification temperature and interface velocity over the entire parametric range, and for both lamellar and rod eutectic morphologies. The analytical solution reveals that ?2V and ??T, though varying with the Peclet number, are

  9. Photochemistry of triarylsulfonium salts

    SciTech Connect

    Dektar, J.L.; Hacker, N.P. (Almaden Research Center, San Jose, CA (USA))

    1990-08-01

    The photolysis of triphenylsulfonium, tris(4-methylphenyl)sulfonium, tris(4-chlorophenyl)sulfonium, several monosubstituted (4-F, 4-Cl, 4-Me, 4-MeO, 4-PhS, and 4-PhCO), and disubstituted (4,4{prime}-Me{sub 2} and 4,4{prime}-(MeO){sub 2}) triphenylsulfonium salts was examined in solution. It was found that direct irradiation of triphenylsulfonium salts produced new rearrangement products, phenylthiobiphenyls, along with diphenyl sulfide, which had been previously reported. Similarly, the triarylsulfonium salts, with the exception of the (4-(phenylthio)phenyl)diphenylsulfonium salts produced new rearrangement products, phenylthiobiphenyls, along with diphenyl sulfide, which had been previously reported. Similarly, the triarylsulfonium salts, with the exception of the (4-(phenylthio)phenyl)diphenylsulfonium salts, gave the new rearrangement products. The mechanism for direct photolysis is proposed to occur from the singlet excited states to give a predominant heterolytic cleavage along with some homolytic cleavage.

  10. Structural and phonon transmission study of Ge-Au-Ge eutectically bonded interfaces

    SciTech Connect

    Knowlton, W.B. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering]|[Lawrence Berkeley Lab., CA (United States). Materials Sciences Div.

    1995-07-01

    This thesis presents a structural analysis and phonon transparency investigation of the Ge-Au-Ge eutectic bond interface. Interface development was intended to maximize the interfacial ballistic phonon transparency to enhance the detection of the dark matter candidate WIMPs. The process which was developed provides an interface which produces minimal stress, low amounts of impurities, and insures Ge lattice continuity through the interface. For initial Au thicknesses of greater than 1,000 {angstrom} Au per substrate side, eutectic epitaxial growth resulted in a Au dendritic structure with 95% cross sectional and 90% planar Au interfacial area coverages. In sections in which Ge bridged the interface, lattice continuity across the interface was apparent. Epitaxial solidification of the eutectic interface with initial Au thicknesses < 500 A per substrate side produced Au agglomerations thereby reducing the Au planar interfacial area coverage to as little as 30%. The mechanism for Au coalescence was attributed to lateral diffusion of Ge and Au in the liquid phase during solidification. Phonon transmission studies were performed on eutectic interfaces with initial Au thicknesses of 1,000 {angstrom}, 500 {angstrom}, and 300 {angstrom} per substrate side. Phonon imaging of eutectically bonded samples with initial Au thicknesses of 300 {angstrom}/side revealed reproducible interfacial percent phonon transmissions from 60% to 70%. Line scan phonon imaging verified the results. Phonon propagation TOF spectra distinctly showed the predominant phonon propagation mode was ballistic. This was substantiated by phonon focusing effects apparent in the phonon imaging data. The degree of interface transparency to phonons and resulting phonon propagation modes correlate with the structure of the interface following eutectic solidification. Structural studies of samples with initial Au thickness of 1,000 {angstrom}/side appear to correspond with the phonon transmission study.

  11. A Dash of Salt 

    E-print Network

    Supercinski, Danielle

    2006-01-01

    more landscapes damaged from too much salt in the water (containing dissolved salts near or in excess of 1,000 parts per million) used for irrigation. ?We just do not have good guidelines to assess potential salinity hazards to landscape plants... with El Paso Water Utilities on plant response to soil salinity. Landscape plant lists for salt tolerance assessment and Photo Guide: Landscape plant response to salinity covers more than 100 species of plants used for landscapes in the Southwest...

  12. Microstructural variations induced by gravity level during directional solidification of near-eutectic iron-carbon type alloys

    NASA Astrophysics Data System (ADS)

    Stefanescu, Doru M.; Curreri, Peter A.; Fiske, Michael R.

    1986-07-01

    The effects of gravity on the microstructure of directionally solidified near-eutectic cast irons are studied, using a Bridgman-type automatic directional solidification furnace aboard a NASA KC-135 aircraft which flies parabolic arcs and generates alternating periods of low-g (0.01 to 0.001 g, 30 seconds long) and high-g (1.8 g, 1.5 minutes long). Results show a refinement of the interlamellar spacing of the eutectic during low-g processing of metastable Fe-C eutectic alloys. Low-g processing of stable Fe-C-Si eutectic alloys (lamellar or spheroidal graphite) results in a coarsening of the eutectic grain structure. Secondary dendrite arm spacing of austenite increases in low-g and decreases in high-g. The effectiveness of low-gravity in the removal of buoyancy-driven graphite phase segregation is demonstrated.

  13. Numerical study of the effect of the shape of the phase diagram on the eutectic freezing temperature

    SciTech Connect

    Ode, M.; Shimono, M. [National Institute for Materials Science (NIMS), Tsukuba (Japan)] [National Institute for Materials Science (NIMS), Tsukuba (Japan); Sasajima, N.; Yamada, Y. [National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (NMIJ, AIST), Tsukuba (Japan)] [National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (NMIJ, AIST), Tsukuba (Japan); Bloembergen, P. [National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (NMIJ, AIST), Tsukuba, Japan and National Institute of Metrology, Beijing 100013 (China)] [National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (NMIJ, AIST), Tsukuba, Japan and National Institute of Metrology, Beijing 100013 (China)

    2013-09-11

    To evaluate the reliability of metal-carbon eutectic systems as fixed points for the next generation of high-temperature standards the effect of thermodynamic properties related to the shape of eutectic phase diagram on the freezing temperature is investigated within the context of the numerical multi-phase-field model. The partition coefficient and liquidus slopes of the two solids involved in the eutectic reaction are varied deliberately and independently. The difference between the eutectic temperature and the freezing temperature is determined in dependence of the solid/liquid (s/l) interface shape and concentration. Where appropriate reference is made to the Jackson-Hunt analytical theory. It is shown that there are mainly two typical conditions to decrease the undercooling: 1) a small liquidus slope and 2) the associated difference between the eutectic composition and the liquid composition during solidification.

  14. Microstructural variations induced by gravity level during directional solidification of near-eutectic iron-carbon type alloys

    NASA Technical Reports Server (NTRS)

    Stefanescu, Doru M.; Fiske, Michael R.; Curreri, Peter A.

    1986-01-01

    The effects of gravity on the microstructure of directionally solidified near-eutectic cast irons are studied, using a Bridgman-type automatic directional solidification furnace aboard a NASA KC-135 aircraft which flies parabolic arcs and generates alternating periods of low-g (0.01 to 0.001 g, 30 seconds long) and high-g (1.8 g, 1.5 minutes long). Results show a refinement of the interlamellar spacing of the eutectic during low-g processing of metastable Fe-C eutectic alloys. Low-g processing of stable Fe-C-Si eutectic alloys (lamellar or spheroidal graphic) results in a coarsening of the eutectic grain structure. Secondary dendrite arm spacing of austenite increases in low-g and decreases in high-g. The effectiveness of low-gravity in the removal of buoyancy-driven graphite phase segregation is demonstrated.

  15. Eutectic Sn\\/Pb solder bump and under bump metallurgy: interfacial reactions and adhesion

    Microsoft Academic Search

    Se-Young Jang; Kyung-Wook Paik

    1998-01-01

    In flip-chip interconnection on organic substrates using eutectic tin\\/lead solder bumps, a highly reliable under bump metallurgy (UBM) is required to maintain adhesion and solder wettability. Various UBM systems such as 1?m Al\\/0.2?m Ti\\/5?m Cu, 1?m Al\\/02?m Ti\\/1?m Cu, 1?m Al\\/0.2?m Ni\\/1?m Cu and 1?m Al\\/0.2?m Pd\\/1?m Cu, applied under eutectic tin\\/lead solder bumps, have been investigated with regard to

  16. The influences of convection on directional solidification of eutectic Bi/MnBi

    NASA Technical Reports Server (NTRS)

    Larson, David J., Jr.

    1988-01-01

    Eutectic alloys of Bi-Mn were directionally solidified using the Bridgman-Stockbarger technique to determine the influences of gravitationally-driven thermo-solutal convection on the Bi-MnBi rod eutectic. Experiments were conducted that varied the level of convection by varying the growth parameters and growth orientation, by microgravity damping, by applied magnetic field damping, and by imposing forced convection. Peltier interface demarcation and in situ thermocouple measurements were used to monitor interface velocity and thermal gradient and to evaluate interface planarity.

  17. Worth its salt?

    NASA Astrophysics Data System (ADS)

    The idea that all underground salt deposits can serve as storage sites for toxic and nuclear waste does not always hold water—literally. According to Daniel Ronen and Brian Berkowitz of Israel's Weizmann Institute of Science and Yoseph Yechieli of the Geological Survey of Israel, some buried salt layers are in fact highly conductive of liquids, suggesting that wastes buried in their confines could easily leech into groundwater and nearby soil.When drilling three wells into a 10,000-year-old salt layer near the Dead Sea, the researchers found that groundwater had seeped into the layer and had absorbed some of its salt.

  18. Salt splitting using ceramic membranes

    SciTech Connect

    Kurath, D.E. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-10-01

    Many radioactive aqueous wastes in the DOE complex have high concentrations of sodium that can negatively affect waste treatment and disposal operations. Sodium can decrease the durability of waste forms such as glass and is the primary contributor to large disposal volumes. Waste treatment processes such as cesium ion exchange, sludge washing, and calcination are made less efficient and more expensive because of the high sodium concentrations. Pacific Northwest National Laboratory (PNNL) and Ceramatec Inc. (Salt Lake City UT) are developing an electrochemical salt splitting process based on inorganic ceramic sodium (Na), super-ionic conductor (NaSICON) membranes that shows promise for mitigating the impact of sodium. In this process, the waste is added to the anode compartment, and an electrical potential is applied to the cell. This drives sodium ions through the membrane, but the membrane rejects most other cations (e.g., Sr{sup +2}, Cs{sup +}). The charge balance in the anode compartment is maintained by generating H{sup +} from the electrolysis of water. The charge balance in the cathode is maintained by generating OH{sup {minus}}, either from the electrolysis of water or from oxygen and water using an oxygen cathode. The normal gaseous products of the electrolysis of water are oxygen at the anode and hydrogen at the cathode. Potentially flammable gas mixtures can be prevented by providing adequate volumes of a sweep gas, using an alternative reductant or destruction of the hydrogen as it is generated. As H{sup +} is generated in the anode compartment, the pH drops. The process may be operated with either an alkaline (pH>12) or an acidic anolyte (pH <1). The benefits of salt splitting using ceramic membranes are (1) waste volume reduction and reduced chemical procurement costs by recycling of NaOH; and (2) direct reduction of sodium in process streams, which enhances subsequent operations such as cesium ion exchange, calcination, and vitrification.

  19. SALT SCALING RESISTANCE OF HIGH-VOLUME CLASS C FLY ASH CONCRETE

    E-print Network

    Wisconsin-Milwaukee, University of

    SALT SCALING RESISTANCE OF HIGH-VOLUME CLASS C FLY ASH CONCRETE Prepared by Center for By salt scaling resistance of high-volume of Class C fly ash concrete systems. Two series of tests were planned. For the first series of tests (Series A) concrete mixture were proportioned to have cement

  20. Method and apparatus for perforating at cutting with a solid fueled gas mixture

    SciTech Connect

    Woytek, A.J.; Lileck, J.T.; Steigerwalt, E.J.

    1984-05-08

    A method for cutting pipe casings and concrete liners or perforating the same and localized portions of surrounding strata in an earth bore is set forth wherein a gas phase cutting or perforating jet mixture of fluorine and nitrogen trifluoride is delivered to the cutting or perforation site from the decomposition of a solid, normally stable, perfluoroammonium salt. An appropriate apparatus for delivering the gas mixture of fluorine and nitrogen trifluoride from the salt is also disclosed.

  1. Fractionation of Deoxyribonucleoprotein by Successive Extraction with Constant Salt Concentration

    Microsoft Academic Search

    J. A. Lucy; J. A. V. Butler

    1954-01-01

    IN recent papers Chargaff and his collaborators1, and Brown and Watson2, have shown the possibility of obtaining nucleic acids (DNA) of varying composition from deoxyribonucleoprotein. Chargaff's fractionation was achieved by successive extractions of nucleoprotein with salt solutions of increasing strength, after the nucleoprotein had been precipitated by a mixture of chloroform and n-octanol. This yielded a series of nucleic acid

  2. Chemical Safety: Molten Salt Baths Cited as Lab Hazards.

    ERIC Educational Resources Information Center

    Baum, Rudy

    1982-01-01

    Discusses danger of explosions with molten salts baths, commonly used as heat-transfer media. One such explosion involved use of a bath containing 3-lb sodium nitrite and 1-lb potassium thiocyanate. Although most commercially available mixtures for heat transfer contain oxidizers, a reducer (thiocyanate) was included which possibly triggered the…

  3. Recovery of valuable materials from aluminium salt cakes

    Microsoft Academic Search

    W. J. Bruckard; J. T. Woodcock

    2009-01-01

    Salt cakes, which are nominally waste products derived from aluminium dross melting furnaces, are complex mixtures of some 20 different compounds made up of many different elements. Normally they are regarded as waste products and they are disposed of in toxic waste dumps. However, it is shown here that some components are readily recoverable as high-grade products for recycling or

  4. Improving crop salt tolerance

    Microsoft Academic Search

    T. J. Flowers

    2004-01-01

    Salinity is an ever-present threat to crop yields, especially in countries where irrigation is an essential aid to agriculture. Although the tolerance of saline conditions by plants is variable, crop species are generally intolerant of one-third of the concentration of salts found in seawater. Attempts to improve the salt tolerance of crops through conventional breeding programmes have met with very

  5. Molten salt electrolyte separator

    DOEpatents

    Kaun, T.D.

    1996-07-09

    The patent describes a molten salt electrolyte/separator for battery and related electrochemical systems including a molten electrolyte composition and an electrically insulating solid salt dispersed therein, to provide improved performance at higher current densities and alternate designs through ease of fabrication. 5 figs.

  6. Acids and Salts (GCMP)

    NSDL National Science Digital Library

    Acids and Salts: this is a resource in the collection "General Chemistry Multimedia Problems". This problem will explore a few properties of common acids and their salts. General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.

  7. Integrated Salt Studies

    NASA Astrophysics Data System (ADS)

    Urai, Janos L.; Kukla, Peter A.

    2015-04-01

    The growing importance of salt in the energy, subsurface storage, and chemical and food industries also increases the challenges with prediction of geometries, kinematics, stress and transport in salt. This requires an approach, which integrates a broader range of knowledge than is traditionally available in the different scientific and engineering disciplines. We aim to provide a starting point for a more integrated understanding of salt, by presenting an overview of the state of the art in a wide range of salt-related topics, from (i) the formation and metamorphism of evaporites, (ii) rheology and transport properties, (iii) salt tectonics and basin evolution, (iv) internal structure of evaporites, (v) fluid flow through salt, to (vi) salt engineering. With selected case studies we show how integration of these domains of knowledge can bring better predictions of (i) sediment architecture and reservoir distribution, (ii) internal structure of salt for optimized drilling and better cavern design, (iii) reliable long-term predictions of deformations and fluid flow in subsurface storage. A fully integrated workflow is based on geomechanical models, which include all laboratory and natural observations and links macro- and micro-scale studies. We present emerging concepts for (i) the initiation dynamics of halokinesis, (ii) the rheology and deformation of the evaporites by brittle and ductile processes, (iii) the coupling of processes in evaporites and the under- and overburden, and (iv) the impact of the layered evaporite rheology on the structural evolution.

  8. Lowering Salt in Your Diet

    MedlinePLUS

    ... this page Home For Consumers Consumer Updates Lowering Salt in Your Diet Search the Consumer Updates Section ... mail Consumer Updates RSS Feed Everyone needs some salt to function. Also known as sodium chloride, salt ...

  9. High thermoelectric figure of merit and improved mechanical properties in melt quenched PbTe-Ge and PbTe-Ge{sub 1-x}Si{sub x} eutectic and hypereutectic composites.

    SciTech Connect

    Sootsman, J. R.; He, J.; Dravid, V. P.; Li, C-P.; Uher, C.; Kanatzidis, M. G. (Materials Science Division); (Northwestern Univ.); (Univ. of Michigan)

    2009-04-01

    We report the synthesis, microstructure, and transport properties of composite thermoelectric materials based on the eutectic phase relationship between PbTe and Ge. When quenched, these eutectic mixtures exhibit considerably stronger mechanical strength and reduced brittleness compared to PbTe itself, while at the same time they possess lower lattice thermal conductivity. Thermal conductivity measurements show values lower than expected based on the law of mixtures and multiphase composites. We find that the thermoelectric performance in these composites can be tuned through the use of hypereutectic compositions and alloying of Ge with Si. PbI{sub 2} was used as an n-type dopant, and precise control of the carrier concentration was achieved to optimize the electrical transport and thermoelectric properties. ZT values approaching 1.3 at 778 K have been obtained in samples of PbTe-Ge{sub 0.8}Si{sub 0.2}(5%), which represent an {approx}62% improvement over that of PbTe.

  10. Geometry Effects on the Electromigration of Eutectic SN\\/PB Flip-Chip Solder Bumps

    Microsoft Academic Search

    Dennis H. Eaton; James D. Rowatt; Walter J. Dauksher

    2006-01-01

    This work investigates the effect of passivation opening diameter and underbump metallization (UBM) diameter on the electromigration (EM) resistance of Sn\\/Pb eutectic solder bumps. For the bump geometries studied, the electromigration lifetime depends strongly on the UBM area but weakly on the passivation opening area. The applicability of Black's model for extrapolating lifetime from accelerated currents to operating currents is

  11. Eutectic solvents for the removal of residual palm oil-based biodiesel catalyst

    Microsoft Academic Search

    K. Shahbaz; F. S. Mjalli; M. A. Hashim; I. M. Alnashef

    2011-01-01

    The production of biodiesel through transesterification requires numerous purification steps to remove the unreacted components and unwanted products for the biodiesel grade to satisfy the international standard specifications EN 14214 and ASTM D6751. The residual catalyst (KOH) is one of those impurities which must be removed at the end of alkali-catalyzed transesterification reaction. In this work, nine Deep eutectic solvents

  12. Prediction of refractive index and density of deep eutectic solvents using atomic contributions

    Microsoft Academic Search

    K. Shahbaz; F. S. G. Bagh; F. S. Mjalli; I. M. AlNashef; M. A. Hashim

    2013-01-01

    Deep eutectic solvents (DESs) are considered as potential alternatives for ionic liquids (ILs). The evaluation of DESs as new generation of solvents for various practical application requires enough knowledge about some main physical, chemical, and thermodynamic properties. In this study, due to lack of data for DESs' refractive indices, the refractive indices of twenty four DESs based on ammonium and

  13. Deep eutectic solvents as novel extraction media for phenolic compounds from model oil.

    PubMed

    Gu, Tongnian; Zhang, Mingliang; Tan, Ting; Chen, Jia; Li, Zhan; Zhang, Qinghua; Qiu, Hongdeng

    2014-10-11

    Deep eutectic solvents (DES) as a new kind of green solvent were used for the first time to excellently extract phenolic compounds from model oil. It was also proved that DES could be used to extract other polar compounds from non-polar or weakly-polar solvents by liquid-phase microextraction. PMID:25144155

  14. Using deep eutectic solvents for the removal of glycerol from palm oil-based biodiesel

    Microsoft Academic Search

    K. Shahbaz; Farouq. S. Mjalli; M. A. Hashim; I. M. Al Nashef

    2010-01-01

    One of the essential steps in the manufacture of biodiesel is its purification from the glycerol by-product. The produced biodiesel should have a low glycerol content which is regarded as one of the important needed pointers for passing the international biodiesel standards. Low cost Deep Eutectic Solvents (DES) have been tested for their solvation properties. In this work, DESs were

  15. Assessment of cytotoxicity and toxicity for phosphonium-based deep eutectic solvents

    Microsoft Academic Search

    M. Hayyan; M. A. Hashim; M. A. Al-Saadi; A. Hayyan; I. M. AlNashef; M. E. S. Mirghani

    2013-01-01

    In this work, the cytotoxicity and toxicity of phosphonium-based deep eutectic solvents (DESs) with three hydrogen bond donors, namely glycerine, ethylene glycol, and triethylene glycol were investigated. The cytotoxicity effect was tested using brine shrimp (. Artemia salina). The toxicity was investigated using the two Gram positive bacteria Bacillus subtilis and Staphylococcus aureus, and two Gram negative bacteria Escherichia coli

  16. Differential capacity of a deep eutectic solvent based on choline chloride and glycerol on solid electrodes

    Microsoft Academic Search

    Marta Figueiredo; Cristiana Gomes; Renata Costa; Ana Martins; Carlos M. Pereira; Fernando Silva

    2009-01-01

    The properties of the interface between platinum, gold and glassy carbon electrodes and a deep eutectic ionic liquid based on choline chloride and glycerol were assessed using cyclic voltammetry and electrochemical impedance spectroscopy. The double layer differential capacitance, obtained from electrochemical impedance, reveals a slight dependence of the potential but it is sensitive to the electrode material. In contrast to

  17. Thermoelectric and morphological effects of peltier pulsing on directional solidification of eutectic Bi-Mn

    Microsoft Academic Search

    R. P. Silberstein; D. J. Larson; B. Dressler

    1984-01-01

    We have carried out extensive in situ thermal measurements during Peltier Interface Demarcation (PID) during directional solidification of eutectic Bi\\/MnBi. We have observed that significant thermal transients occur throughout the sample as a result of the Peltier pulsing. We have separated the contributions of the Peltier, Thomson, and Joule heats, and studied them as a function of pulse intensity and

  18. Damage by eutectic particle cracking in aluminum casting alloys A356\\/357

    Microsoft Academic Search

    Q. G. Wang; C. H. Caceres; J. R. Griffiths

    2003-01-01

    The strain dependence of particle cracking in aluminum alloys A356\\/357 in the T6 temper has been studied in a range of microstructures produced by varying solidification rate and Mg content, and by chemical (Sr) modification of the eutectic silicon. The damage accumulates linearly with the applied strain for all microstructures, but the rate depends on the secondary dendrite arm spacing

  19. A New Analytical Approach to Predict Spacing Selection in Lamellar and Rod Eutectic Systems

    NASA Technical Reports Server (NTRS)

    Catalina, Adrian V.; Sen, Subhayu; Stefanescu, Doru M.

    2003-01-01

    The Jackson and Hunt (JH) theory has been modified to relax the assumption of isothermal solid liquid interface used in their treatment. Based on the predictions of this modified theory, the traditional definitions of regular and irregular eutectics are revised. For regular eutectics, the new model identifies a range of spacing within the limits defined by the minimum undercooling of the a and beta phases. For the irregular Al-Si eutectic system, two different spacing selection mechanisms were identified: (1) for a particular growth rate, a nearly isothermal interface can be achieved at a unique minimum spacing lambda (sub t); (2) the average spacing (lambda (sub av) greater than lambda (sub t) is essentially dictated by the undercooling of the faceted phase. Based on the modified theoretical model, a semiempirical expression has been developed to account for the influence of the temperature gradient, which is dominant in the irregular Al-Si system. The behavior of the Fe-Fe3C eutectic is also discussed. The theoretical calculations have been found to be in good agreement with the published experimental measurements.

  20. A New Analytical Approach to Predict Spacing Selection in Lamellar and Rod Eutectic Systems

    NASA Technical Reports Server (NTRS)

    Catalina, Adrian V.; Sen, Subhayu; Stefanescu, D. M.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    The Jackson and Hunt (JH) theory has been modified to relax the assumption of isothermal solid/liquid interface(SLI) used in their treatment. Based on the predictions of this modified theory the traditional definitions of regular and irregular eutectics are revised. For regular eutectics the new model identifies a range of spacing within the limits defined by the minimum undercooling of the alpha and beta phase. For the irregular Al-Si eutectic system two different spacing selection mechanisms were identified: a) for a particular growth rate, a nearly isothermal interface can be achieved at a unique minimum spacing lambda(sub I); b) the average spacing (lambda(sub av) greater than lambda(sub I)) is essentially dictated by the undercooling of the faceted phase. Based on the modified theoretical model a semiempirical expression has been developed to account for the influence of the temperature gradient, which is dominant in the irregular Al-Si system. The behavior of the Fe-Fe3C eutectic is also discussed The theoretical calculations have been found to be in good agreement with the published experimental measurements.

  1. REVIEW OF THE INFLUENCE OF CONVECTION ON THE MICROSTRUCTURE OF FIBROUS EUTECTICS

    E-print Network

    Regel, Liya L.

    convection. Most experiments were performed on the MnBi-Bi eutectic. The rod spacing depended on the growth that directional solidification in microgravity caused a significant reduction in the fiber spacing of the MnBi experiments showed that the effect was real and reproducible [3-13]. Since Larson's ASTP experiment on Mn-Bi

  2. Critical temperature of the leadbismuth eutectic (LBE) alloy Abdul-Majeed Azad *

    E-print Network

    Azad, Abdul-Majeed

    ; boiling point = 2022 K) and Pb (melting point = 600 K; boiling point = 1837 K) as well as the Pb­Bi eutectic alloy (LBE, melting point = 396 K; boil- ing point = 1943 K) have been serious contenders for use neutron absorption and activation, high boiling point and poor interaction with water and air, etc

  3. Damage by eutectic particle cracking in aluminum casting alloys A356/357

    NASA Astrophysics Data System (ADS)

    Wang, Q. G.; Caceres, C. H.; Griffiths, J. R.

    2003-12-01

    The strain dependence of particle cracking in aluminum alloys A356/357 in the T6 temper has been studied in a range of microstructures produced by varying solidification rate and Mg content, and by chemical (Sr) modification of the eutectic silicon. The damage accumulates linearly with the applied strain for all microstructures, but the rate depends on the secondary dendrite arm spacing and modification state. Large and elongated eutectic silicon particles in the unmodified alloys and large ?-phase (Al9FeMg3Si5) particles in alloy A357 show the greatest tendency to cracking. In alloy A356, cracking of eutectic silicon particles dominates the accumulation of damage while cracking of Fe-rich particles is relatively unimportant. However, in alloy A357, especially with Sr modification, cracking of the large ?-phase intermetallics accounts for the majority of damage at low and intermediate strains but becomes comparable with silicon particle cracking at large strains. Fracture occurs when the volume fraction of cracked particles (eutectic silicon and Fe-rich intermetallics combined) approximates 45 pct of the total particle volume fraction or when the number fraction of cracked particles is about 20 pct. The results are discussed in terms of Weibull statistics and existing models for dispersion hardening.

  4. Free energy change of off-eutectic binary alloys on solidification

    NASA Technical Reports Server (NTRS)

    Ohsaka, K.; Trinh, E. H.; Lin, J.-C.; Perepezko, J. H.

    1991-01-01

    A formula for the free energy difference between the undercooled liquid phase and the stable solid phase is derived for off-eutectic binary alloys in which the equilibrium solid/liquid transition takes place over a certain temperature range. The free energy change is then evaluated numerically for a Bi-25 at. pct Cd alloy modeled as a sub-subregular solution.

  5. Eutectic freeze crystallization: Application to process streams and waste water purification

    Microsoft Academic Search

    F. van der Ham; G. J. Witkamp; J. de Graauw; G. M. van Rosmalen

    1998-01-01

    Two case studies are presented using eutectic freeze crystallization (EFC) as an alternative for evaporative crystallization: a 7.8 ton day?1 35 w% aqueous sodium nitrate and a 24 ton day?1 12 w% copper sulfate stream. The proposed crystallizer is a cooled disk column crystallizer (CDCC), using indirect cooling for heat transfer. In single stage operation, the formed ice crystals are

  6. Quantitative modeling of diffusional coarsening in eutectic tin\\/lead solders

    Microsoft Academic Search

    W. Dreyer

    2000-01-01

    This paper presents a quantitative computer simulation of the coarsening phenomenon observed in eutectic tin\\/lead and other solder materials used for joining microelectronic components. The mathematical model is based on phase field theory and allows predicting the development of tin concentration over time within a representative volume element (RVE) of the solder. It accounts for the chemical free energy of

  7. Experimental investigation of forced-convection heat-transfer characteristics of lead-bismuth eutectic

    NASA Technical Reports Server (NTRS)

    Lubarsky, Bernard

    1951-01-01

    The forced-convection heat-transfer characteristics of lead-bismuth eutectic were experimentally investigated. Experimental values of Nusselt number for lead-bismuth fell considerably below predicted values. The addition of a wetting agent did not change the heat transfer characteristics.

  8. Evaluation of magnesium-aluminum eutectic to improve combustion efficiency in low burning rate propellants

    NASA Technical Reports Server (NTRS)

    Northam, B. G.; Sullivan, E. M.

    1973-01-01

    A previous investigation indicated that combustion efficiency of low burning-rate propellants could be improved if the aluminum fuel was replaced by aluminum particles coated with a magnesium-aluminum eutectic alloy (ALCAL). The purpose of the present investigation was to evaluate the possibility of improving the combustion efficiency of these propellants by admixing the eutectic with the aluminum rather than coating the aluminum. Tests of three propellants similar in every respect except for the metal fuel were conducted in test motors with 4.54 kg (10 lbm) of propellant. The first propellant used aluminum fuel; the second contained aluminum admixed with magnesium-aluminum eutectic; the third used ALCAL. The test results show the the admixed fuel gave better low burning-rate combustion efficiency than the other two. The test results also showed that the ALCAL was deficient in that much, if not all, of the coating material could be found as the fine particles in a bimodal mix of aluminum and eutectic. The combustion efficiency of low burning-rate aluminized propellants can be significantly improved by mixing a small amount of magnesium-aluminum alloy with the aluminum fuel.

  9. The Effect of Silica Nanoparticles on Corrosion of Steel by Molten Carbonate Eutectics

    E-print Network

    Padmanaban Iyer, Ashwin

    2011-08-08

    The effect of silica nanoparticles on corrosion of steel by molten carbonate eutectic (42.7 percent Li2CO3, K2CO3) was investigated. The experimental design was based on static coupon immersion methodology where a coupon (material under study...

  10. High cycle fatigue of tantalum carbide reinforced nickel base eutectics at room temperature

    Microsoft Academic Search

    D. E. Graham; D. A. Woodford

    1979-01-01

    The high cycle fatigue response of two advanced tantalum carbide strengthened eutectic superalloys has been determined at room temperature. Since these alloys will be coated in service, the effects of variables associated with coating processes were given special attention. Both alloys showed a well defined fatigue limit. It was concluded that the maximum stress obtained in the cycle at the

  11. GENERATION OF ULTRA-FINE EUTECTIC MICROSTRUCTURES IN AS-SOLIDIFIED METALS

    E-print Network

    Floreano, Dario

    undercooling competition observed is confirmed by directional solidification and samples solidifiedGENERATION OF ULTRA-FINE EUTECTIC MICROSTRUCTURES IN AS-SOLIDIFIED METALS Étienne Landry-Désy1 Al-Cu-Si sample (600 µm thick) 2 1 DECREASING COOLING RATE The liquid directly contacting the cold

  12. Mechanical Properties and Fracture Behavior of Directionally Solidified NiAl-V Eutectic Composites

    NASA Astrophysics Data System (ADS)

    Milenkovic, Srdjan; Caram, Rubens

    2015-02-01

    Directional solidification of eutectic alloys has been recognized as promising technique for producing in situ composite materials exhibiting balance of properties. Therefore, an in situ NiAl-V eutectic composite has been successfully directionally solidified using Bridgman technique. The mechanical behavior of the composite including fracture resistance, microhardness, and compressive properties at room and elevated temperatures was investigated. Damage evolution and fracture characteristics were also discussed. The obtained results indicate that the NiAl-V eutectic retains high yield strength up to 1073 K (800 °C), above which there is a rapid decrease in strength. Its yield strength is higher than that of binary NiAl and most of the NiAl-based eutectics. The exhibited fracture toughness of 28.5 MPa?m is the highest of all other NiAl-based systems investigated so far. The material exhibited brittle fracture behavior of transgranular type and all observations pointed out that the main fracture micromechanism was cleavage.

  13. CONTROLLED POTENTIAL COULOMETRY IN FUSED LITHIUM CHLORIDE-POTASSIUM CHLORIDE EUTECTIC

    Microsoft Academic Search

    Van Norman

    1962-01-01

    Analyses for Zn(II) and Cd(II) in the fused lithium chloride - potassium ; chloride eutectic at 450 deg C were performed by controlled potential coulometric ; stripping of the predeposited metal from a bismuth pool electrode, and Ni(II) was ; determined by controlled potential stripping of the predeposited metal from a ; platinum gauze electrode. Analyses were performed with an

  14. Resedimented salt deposits

    SciTech Connect

    Slaczka, A.; Kolasa, K. (Jagiellonian Univ., Krakow (Poland))

    1988-08-01

    Carparthian foredeep's Wieliczka salt mine, unique gravity deposits were lately distinguished. They are mainly built of salt particles and blocks with a small admixture of fragments of Miocene marls and Carpathian rocks, deposited on precipitated salt. The pattern of sediment distribution is similar to a submarine fan. Gravels are dominant in the upper part and sands in lower levels, creating a series of lobes. Coarse-grained deposits are represented by disorganized, self-supported conglomerates passing into matrix-supported ones, locally with gradation, and pebbly sandstones consisting of salt grains and scattered boulder-size clasts. The latter may show in the upper part of a single bed as indistinct cross-bedding and parallel lamination. These sediments are interpreted as debris-flow and high-density turbidity current deposits. Salt sandstones (saltstones) which build a lower part of the fan often show Bouma sequences and are interpreted as turbidity-current deposits. The fan deposits are covered by a thick series of debrites (olistostromes) which consist of clay matrix with salt grains and boulders. The latter as represented by huge (up to 100,000 m{sup 3}) salt blocks, fragments of Miocene marls and Carpathian rocks. These salt debrites represent slumps and debris-flow deposits. The material for resedimented deposits was derived from the southern part of the salt basin and from the adjacent, advancing Carpathian orogen. The authors believe the distinct coarsening-upward sequence of the series is the result of progressive intensification of tectonic movements with paroxysm during the sedimentation of salt debrites (about 15 Ma).

  15. Water purification using organic salts

    DOEpatents

    Currier, Robert P.

    2004-11-23

    Water purification using organic salts. Feed water is mixed with at least one organic salt at a temperature sufficiently low to form organic salt hydrate crystals and brine. The crystals are separated from the brine, rinsed, and melted to form an aqueous solution of organic salt. Some of the water is removed from the aqueous organic salt solution. The purified water is collected, and the remaining more concentrated aqueous organic salt solution is reused.

  16. Low-melting mixtures based on choline ionic liquids.

    PubMed

    Rengstl, Doris; Fischer, Veronika; Kunz, Werner

    2014-11-01

    In this article a strategy is proposed for the design of low toxic, room temperature liquid low-melting mixtures (LMMs) which are entirely composed of natural materials. From literature it is well known that, in general, deep eutectic solvents based on choline chloride and dicarboxylic acids are LMMs, but not liquids at room temperature, with one exception: a 1?:?1 molar mixture of malonic acid and choline chloride. Therefore, the starting point of this study was the decrease of the melting point of one of the components, namely the dicarboxylic acid, which is succinic, glutaric or adipic acid. For this purpose, one of the two protons of the acidic group was exchanged by a bulky unsymmetrical choline cation. The resulting ionic liquids (ILs) were still solid at room temperature, but have a reduced melting temperature compared to the corresponding acids. In the second step, mixtures of these ILs with choline chloride were prepared. It turned out that choline glutarate-choline chloride mixtures are liquids at room temperature at compositions containing 95-98 wt% of choline glutarate. Finally, urea was added as another hydrogen bond donor. Density, conductivity and viscosity measurements were performed for all obtained mixtures. Moreover, a Walden plot was drawn which indicates that all mixtures are liquids with fully dissociated ions moving independently. Therefore, they are considered as "good" ionic liquids and, thus, for example they can be used to exchange more toxic or less biodegradable ILs in application processes. A brief outlook containing application possibilities is given. It is demonstrated that choline dodecylsulfate is readily soluble in these mixtures, forming aggregates in the LMM at temperatures exceeding 55 °C. PMID:25242504

  17. Element, Mixture, Compound

    NSDL National Science Digital Library

    2014-09-18

    Students gain a better understanding of the different types of materials as pure substances and mixtures and learn to distinguish between homogeneous and heterogeneous mixtures by discussing an assortment of example materials they use and encounter in their daily lives.

  18. Soluble salts at the Phoenix Lander site, Mars: A reanalysis of the Wet Chemistry Laboratory data

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

    The Wet Chemistry Laboratory (WCL) on the Phoenix Mars Scout Lander analyzed soils for soluble ions and found Ca2+, Mg2+, Na+, K+, Cl-, SO42-, and ClO4-. The salts that gave rise to these ions can be inferred using aqueous equilibrium models; however, model predictions are sensitive to the initial solution composition. This is problematic because the WCL data is noisy and many different ion compositions are possible within error bounds. To better characterize ion concentrations, we reanalyzed WCL data using improvements to original analyses, including Kalman optimal smoothing and ion-pair corrections. Our results for Rosy Red are generally consistent with previous analyses, except that Ca2+ and Cl- concentrations are lower. In contrast, ion concentrations in Sorceress 1 and Sorceress 2 are significantly different from previous analyses. Using the more robust Rosy Red WCL analysis, we applied equilibrium models to determine salt compositions within the error bounds of the reduced data. Modeling with FREZCHEM predicts that WCL solutions evolve Ca-Mg-ClO4-rich compositions at low temperatures. These unusual compositions are likely influenced by limitations in the experimental data used to parameterize FREZCHEM. As an alternative method to evaluate salt assemblages, we employed a chemical divide model based on the eutectic temperatures of salts. Our chemical divide model predicts that the most probable salts in order of mass abundance are MgSO4·11H2O (meridianiite), MgCO3·nH2O, Mg(ClO4)2·6H2O, NaClO4·2H2O, KClO4, NaCl·2H2O (hydrohalite), and CaCO3 (calcite). If ClO3- is included in the chemical divide model, then NaClO3 precipitates instead of NaClO4·2H2O and Mg(ClO3)2·6H2O precipitates in addition to Mg(ClO4)2·6H2O. These salt assemblages imply that at least 1.3 wt.% H2O is bound in the soil, noting that we cannot account for water in hydrated insoluble salts or deliquescent brines. All WCL solutions within error bounds precipitate Mg(ClO4)2·6H2O and/or Mg(ClO3)2·6H2O salts. These salts have low eutectic temperatures and are highly hygroscopic, which suggests that brines will be stable in soils for much of the Martian summer.

  19. Deep eutectic solvents: sustainable media for nanoscale and functional materials.

    PubMed

    Wagle, Durgesh V; Zhao, Hua; Baker, Gary A

    2014-08-19

    Deep eutectic solvents (DESs) represent an alternative class of ionic fluids closely resembling room-temperature ionic liquids (RTILs), although, strictly speaking, they are distinguished by the fact that they also contain an organic molecular component (typically, a hydrogen bond donor like a urea, amide, acid, or polyol), frequently as the predominant constituent. Practically speaking, DESs are attractive alternatives to RTILs, sharing most of their remarkable qualities (e.g., tolerance to humidity, negligible vapor pressure, thermostability, wide electrochemical potential windows, tunability) while overcoming several limitations associated with their RTIL cousins. Particularly, DESs are typically, less expensive, more synthetically accessible (typically, from bulk commodity chemicals using solvent/waste-free processes), nontoxic, and biodegradable. In this Account, we provide an overview of DESs as designer solvents to create well-defined nanomaterials including shape-controlled nanoparticles, electrodeposited films, metal-organic frameworks, colloidal assemblies, hierarchically porous carbons, and DNA/RNA architectures. These breakthroughs illustrate how DESs can fulfill multiple roles in directing chemistry at the nanoscale: acting as supramolecular template, metal/carbon source, sacrificial agent (e.g., ammonia release from urea), and/or redox agent, all in the absence of formal stabilizing ligand (here, solvent and stabilizer are one and the same). The ability to tailor the physicochemical properties of DESs is central to controlling their interfacial behavior. The preorganized "supramolecular" nature of DESs provides a soft template to guide the formation of bimodal porous carbon networks or the evolution of electrodeposits. A number of essential parameters (viscosity, polarity, surface tension, hydrogen bonding), plus coordination with solutes/surfaces, all play significant roles in modulating species reactivity and mass transport properties governing the genesis of nanostructure. Furthermore, DES components may modulate nucleation and growth mechanisms by charge neutralization, modification of reduction potentials (or chemical activities), and passivation of particular crystal faces, dictating growth along preferred crystallographic directions. Broad operational windows for electrochemical reactions coupled with their inherent ionic nature facilitate the electrodeposition of alloys and semiconductors inaccessible to classical means and the use of cosolvents or applied potential control provide under-explored strategies for mediating interfacial interactions leading to control over film characteristics. The biocompatibility of DESs suggests intriguing potential for the construction of biomolecular architectures in these novel media. It has been demonstrated that nucleic acid structures can be manipulated in the ionic, crowded, dehydrating (low water activity) DES environment-including the adoption of duplex helical structures divergent from the canonical B form and parallel G-quadruplex DNA persisting near water's boiling point-challenging the misconception that water is a necessity for maintenance of nucleic acid structure/functionality and suggesting an enticing trajectory toward DNA/RNA-based nanocatalysis within a strictly anhydrous medium. DESs offer tremendous opportunities and open intriguing perspectives for generating sophisticated nanostructures within an anhydrous or low-water medium. We conclude this Account by offering our thoughts on the evolution of the field, pointing to areas of clear and compelling utility which will surely see fruition in the coming years. Finally, we highlight a few hurdles (e.g., need for a universal nomenclature, absence of water-immiscible, oriented-phase, and low-viscosity DESs) which, once navigated, will hasten progress in this area. PMID:24892971

  20. Nickel solubility limit in liquid lead-bismuth eutectic

    NASA Astrophysics Data System (ADS)

    Martinelli, L.; Vanneroy, F.; Diaz Rosado, J. C.; L'Hermite, D.; Tabarant, M.

    2010-05-01

    In the framework of the Accelerator-Driven System (ADS), the Pb-Bi eutectic can be used as spallation target for neutron production. The Pb-Bi flow in contact with the ADS structural steels, T 91 (Fe-9Cr martensitic steel) and 316L (Fe-17Cr-10Ni austenitic steel), can dissolve the main steel components: iron, chromium and nickel. According to literature, in low oxygen containing Pb-Bi, the dissolution rates of 316L depend, at least, on the nickel solubility limit as it dissolves preferentially in the Pb-Bi alloy. Consequently, the determination of this physico-chemical data in the temperature range of the ADS operating conditions (350-450 °C) is needed for the prediction of the corrosion rates in ADS. The nickel solubility limit in Pb-Bi is available in the literature from 400 °C to 900 °C but not for lower temperatures. However, the Ni-Bi phase diagram leads one to suppose that the nickel solubility limit law changes for lower temperatures. Consequently in this study, two experimental techniques have been implemented for the determination of the nickel solubility limit at low temperatures. The first one is performed from 400 °C to 500 °C using the Laser Induce Breakdown Spectroscopy (LIBS). The LIBS technique permits to obtain in situ measurements directly performed on liquid Pb-Bi. This characteristic is very interesting as it allows to monitor on line the concentration of the dissolved impurities in the liquid coolant. However, this technique is still under development and optimization on liquid Pb-Bi medium. The second technique is ICP-AES. This technique, commonly used to analyze alloys composition, is interesting as it permits a global analysis of a Pb-Bi sample. Moreover, the measurement made by ICP-AES is very reliable, very accurate and optimized for such analyses. However, this technique is ex situ; this is its main disadvantage. Experiments using ICP-AES were performed from 350 °C to 535 °C. The two techniques lead to the same solubility limit in their common temperature range. However, the experiment using ICP-AES technique revealed a change in the nickel solubility law for the temperatures lower than 415 °C. Consequently, this study recommends the use of two solubility limits relations, which take into account these results, as well as the literature results: the solubility limits laws of Martynov and Rosenblatt. The nickel solubility limit can thus be expressed as: Log S(wt.%)=5.2±0.12-{3500}/{T(K)} for the temperature range: 330-415 °C. This law is the empirical solubility law obtained in this study at the low temperature range. Log S(wt.%)=1.7±0.08-{1009}/{T(K)} for 415-900 °C temperature range. This law is the linear regression made on the overall experimental points available in literature and in this study. According to the Martynov studies, it seems reliable up to 900 °C.

  1. Natural deep eutectic solvents as new potential media for green technology.

    PubMed

    Dai, Yuntao; van Spronsen, Jaap; Witkamp, Geert-Jan; Verpoorte, Robert; Choi, Young Hae

    2013-03-01

    Developing new green solvents is one of the key subjects in Green Chemistry. Ionic liquids (ILs) and deep eutectic solvents, thus, have been paid great attention to replace current harsh organic solvents and have been applied to many chemical processing such as extraction and synthesis. However, current ionic liquids and deep eutectic solvents have still limitations to be applied to a real chemical industry due to toxicity against human and environment and high cost of ILs and solid state of most deep eutectic solvents at room temperature. Recently we discovered that many plant abundant primary metabolites changed their state from solid to liquid when they were mixed in proper ratio. This finding made us hypothesize that natural deep eutectic solvents (NADES) play a role as alternative media to water in living organisms and tested a wide range of natural products, which resulted in discovery of over 100 NADES from nature. In order to prove deep eutectic feature the interaction between the molecules was investigated by nuclear magnetic resonance spectroscopy. All the tested NADES show clear hydrogen bonding between components. As next step physical properties of NADES such as water activity, density, viscosity, polarity and thermal properties were measured as well as the effect of water on the physical properties. In the last stage the novel NADES were applied to the solubilization of wide range of biomolecules such as non-water soluble bioactive natural products, gluten, starch, and DNA. In most cases the solubility of the biomolecules evaluated in this study was greatly higher than water. Based on the results the novel NADES may be expected as potential green solvents at room temperature in diverse fields of chemistry. PMID:23427801

  2. Transient and steady state creep response of ice I and magnesium sulfate hydrate eutectic aggregates

    USGS Publications Warehouse

    McCarthy, C.; Cooper, R.F.; Goldsby, D.L.; Durham, W.B.; Kirby, S.H.

    2011-01-01

    Using uniaxial compression creep experiments, we characterized the transient and steady state deformation behaviors of eutectic aggregates of system ice I and MgSO4 11H2O (MS11; meridianiite), which has significance because of its likely presence on moons of the outer solar system. Synthetic samples of eutectic liquid bulk composition, which produce eutectic colonies containing 0.35-0.50 volume fraction MS11, were tested as functions of colony size and lamellar spacing, temperature (230-250 K), and confining pressure (0.1 and 50 MPa) to strains ???0.2. Up to a differential stress of 6 MPa, the ice I-MS11 aggregates display an order of magnitude higher effective viscosity and higher stress sensitivity than do aggregates of pure polycrystalline ice at the same conditions. The creep data and associated microstructural observations demonstrate, however, that the aggregates are additionally more brittle than pure ice, approaching rate-independent plasticity that includes rupture of the hydrate phase at 6-8 MPa, depending on the scale of the microstructure. Microstructures of deformed samples reveal forms of semibrittle flow in which the hydrate phase fractures while the ice phase deforms plastically. Semibrittle flow in the icy shell of a planetary body would truncate the lithospheric strength envelope and thereby decrease the depth to the brittle-ductile transition by 55% and reduce the failure limit for compressional surface features from 10 to ???6 MPa. A constitutive equation that includes eutectic colony boundary sliding and intracolony flow is used to describe the steady state rheology of the eutectic aggregates. Copyright ?? 2011 by the American Geophysical Union.

  3. Refinement of Eutectic Si in High Purity Al-5Si Alloys with Combined Ca and P Additions

    NASA Astrophysics Data System (ADS)

    Ludwig, Thomas Hartmut; Li, Jiehua; Schaffer, Paul Louis; Schumacher, Peter; Arnberg, Lars

    2015-01-01

    The effects of combined additions of Ca and P on the eutectic Si in a series of high purity Al-5 wt pct Si alloys have been investigated with the entrained droplet technique and complementary sets of conventional castings. Differential scanning calorimetry (DSC) and thermal analysis were used to investigate the eutectic droplet undercooling and the recalescence undercooling, respectively. Optical microscopy, SEM, EPMA, and TEM were employed to characterize the resultant microstructures. It was found that 250 ppm Ca addition to Al-5Si wt pct alloys with higher P contents leads to a significant increase of the eutectic droplet undercooling. For low or moderate cooling rates, the TEM results underline that Ca additions do not promote Si twinning. Thus, a higher twin density cannot be expected in Ca containing Al-Si alloys after, e.g., sand casting. Consequently, a refinement of the eutectic Si from coarse flake-like to fine plate-like structure, rather than a modification of the eutectic Si to a fibrous morphology, was achieved. This strongly indicates that the main purpose of Ca additions is to counteract the coarsening effect of the eutectic Si imposed by higher P concentrations. Significant multiple Si twinning was observed in melt-spun condition; however, this can be attributed to the higher cooling rate. After DSC heating (slow cooling), most of Si twins disappeared. Thus, the well-accepted impurity-induced twinning mechanism may be not valid in the case of Ca addition. The possible refinement mechanisms were discussed in terms of nucleation and growth of eutectic Si. We propose that the pre-eutectic Al2Si2Ca phase and preferential formation of Ca3P2 deactivate impurity particles, most likely AlP, poisoning the nucleation sites for eutectic Si.

  4. Upward Dead-End Ultrafiltration of Binary Protein Mixtures

    Microsoft Academic Search

    Eiji Iritani; Yasuhito Mukai; Toshiro Murase

    1995-01-01

    Upward dead-end ultrafiltration of aqueous solutions of mixtures of bovine serum albumin (BSA) and egg white lysozyme was conducted using membranes which are almost completely retentive for BSA but permeable for lysozyme. The dependence of lysozyme rejection and the filtration flux rate on pH and the addition of salts has been investigated. The experimental data obtained in this study clearly

  5. Supercritical Water Mixture (SCWM) Experiment

    NASA Technical Reports Server (NTRS)

    Hicks, Michael C.; Hegde, Uday G.

    2012-01-01

    The subject presentation, entitled, Supercritical Water Mixture (SCWM) Experiment, was presented at the International Space Station (ISS) Increment 33/34 Science Symposium. This presentation provides an overview of an international collaboration between NASA and CNES to study the behavior of a dilute aqueous solution of Na2SO4 (5% w) at near-critical conditions. The Supercritical Water Mixture (SCWM) investigation, serves as important precursor work for subsequent Supercritical Water Oxidation (SCWO) experiments. The SCWM investigation will be performed in DECLICs High Temperature Insert (HTI) for the purpose of studying critical fluid phenomena at high temperatures and pressures. The HTI includes a completely sealed and integrated test cell (i.e., Sample Cell Unit SCU) that will contain approximately 0.3 ml of the aqueous test solution. During the sequence of tests, scheduled to be performed in FY13, temperatures and pressures will be elevated to critical conditions (i.e., Tc = 374C and Pc = 22 MPa) in order to observe salt precipitation, precipitate agglomeration and precipitate transport in the presence of a temperature gradient without the influences of gravitational forces. This presentation provides an overview of the motivation for this work, a description of the DECLIC HTI hardware, the proposed test sequences, and a brief discussion of the scientific research objectives.

  6. Crushed Salt Constitutive Model

    SciTech Connect

    Callahan, G.D.

    1999-02-01

    The constitutive model used to describe the deformation of crushed salt is presented in this report. Two mechanisms -- dislocation creep and grain boundary diffusional pressure solution -- are combined to form the basis for the constitutive model governing the deformation of crushed salt. The constitutive model is generalized to represent three-dimensional states of stress. Upon complete consolidation, the crushed-salt model reproduces the Multimechanism Deformation (M-D) model typically used for the Waste Isolation Pilot Plant (WIPP) host geological formation salt. New shear consolidation tests are combined with an existing database that includes hydrostatic consolidation and shear consolidation tests conducted on WIPP and southeastern New Mexico salt. Nonlinear least-squares model fitting to the database produced two sets of material parameter values for the model -- one for the shear consolidation tests and one for a combination of the shear and hydrostatic consolidation tests. Using the parameter values determined from the fitted database, the constitutive model is validated against constant strain-rate tests. Shaft seal problems are analyzed to demonstrate model-predicted consolidation of the shaft seal crushed-salt component. Based on the fitting statistics, the ability of the model to predict the test data, and the ability of the model to predict load paths and test data outside of the fitted database, the model appears to capture the creep consolidation behavior of crushed salt reasonably well.

  7. Trace water content of salt in Louisiana salt domes

    Microsoft Academic Search

    L. P. Knauth; M. B. Kumar

    1981-01-01

    The trace water content of salt in six Louisiana salt domes has been determined and has been found to be the lowest of any terrestrial rock type. The average water content of normal domal salt is on the order of 0.003 percent by weight, but anomalous zones within salt stocks can have more than ten times this amount. From the

  8. Capric acid and palmitic acid eutectic mixture applied in building wallboard for latent heat thermal ener gy storage

    Microsoft Academic Search

    Ali Karaipekli; Ahmet Sari

    TES medium, which can be applied to peak load shifting, improved use of waste heat and solar ener gy as well as more ef ficient operation of heating and cooling equipment. In addition, PCW has good thermal reliability in terms of the changes in its thermal properties after accelerated 1000, 2000, 3000, 4000, and 5000 thermal cycling. Use of such

  9. Electrodialysis technology for salt recovery from aluminum salt cake

    SciTech Connect

    Hryn, J. N.; Krumdick, G.; Graziano, D.; Sreenivasarao, K.

    2000-02-02

    Electrodialysis technology for recovering salt from aluminum salt cake is being developed at Argonne National Laboratory. Salt cake, a slag-like aluminum-industry waste stream, contains aluminum metal, salt (NaCl and KCl), and nonmetallics (primarily aluminum oxide). Salt cake can be recycled by digesting with water and filtering to recover the metal and oxide values. A major obstacle to widespread salt cake recycling is the cost of recovering salt from the process brine. Electrodialysis technology developed at Argonne appears to be a cost-effective approach to handling the salt brines, compared to evaporation or disposal. In Argonne's technology, the salt brine is concentrated until salt crystals are precipitated in the electrodialysis stack; the crystals are recovered downstream. The technology is being evaluated on the pilot scale using Eurodia's EUR 40-76-5 stack.

  10. Novel Molten Salts Thermal Energy Storage for Concentrating Solar Power Generation

    SciTech Connect

    Reddy, Ramana G. [The University of Alabama] [The University of Alabama

    2013-10-23

    The explicit UA program objective is to develop low melting point (LMP) molten salt thermal energy storage media with high thermal energy storage density for sensible heat storage systems. The novel Low Melting Point (LMP) molten salts are targeted to have the following characteristics: 1. Lower melting point (MP) compared to current salts (<222ºC) 2. Higher energy density compared to current salts (>300 MJ/m3) 3. Lower power generation cost compared to current salt In terms of lower power costs, the program target the DOE's Solar Energy Technologies Program year 2020 goal to create systems that have the potential to reduce the cost of Thermal Energy Storage (TES) to less than $15/kWh-th and achieve round trip efficiencies greater than 93%. The project has completed the experimental investigations to determine the thermo-physical, long term thermal stability properties of the LMP molten salts and also corrosion studies of stainless steel in the candidate LMP molten salts. Heat transfer and fluid dynamics modeling have been conducted to identify heat transfer geometry and relative costs for TES systems that would utilize the primary LMP molten salt candidates. The project also proposes heat transfer geometry with relevant modifications to suit the usage of our molten salts as thermal energy storage and heat transfer fluids. The essential properties of the down-selected novel LMP molten salts to be considered for thermal storage in solar energy applications were experimentally determined, including melting point, heat capacity, thermal stability, density, viscosity, thermal conductivity, vapor pressure, and corrosion resistance of SS 316. The thermodynamic modeling was conducted to determine potential high temperature stable molten salt mixtures that have thermal stability up to 1000 °C. The thermo-physical properties of select potential high temperature stable (HMP) molten salt mixtures were also experimentally determined. All the salt mixtures align with the go/no-go goals stipulated by the DOE for this project. Energy densities of all salt mixtures were higher than that of the current solar salt. The salt mixtures costs have been estimated and TES system costs for a 2 tank, direct approach have been estimated for each of these materials. All estimated costs are significantly below the baseline system that used solar salt. These lower melt point salts offer significantly higher energy density per volume than solar salt – and therefore attractively smaller inventory and equipment costs. Moreover, a new TES system geometry has been recommended A variety of approaches were evaluated to use the low melting point molten salt. Two novel changes are recommended that 1) use the salt as a HTF through the solar trough field, and 2) use the salt to not only create steam but also to preheat the condensed feedwater for Rankine cycle. The two changes enable the powerblock to operate at 500°C, rather than the current 400°C obtainable using oil as the HTF. Secondly, the use of salt to preheat the feedwater eliminates the need to extract steam from the low pressure turbine for that purpose. Together, these changes result in a dramatic 63% reduction required for 6 hour salt inventory, a 72% reduction in storage volume, and a 24% reduction in steam flow rate in the power block. Round trip efficiency for the Case 5 - 2 tank “direct” system is estimated at >97%, with only small losses from time under storage and heat exchange, and meeting RFP goals. This attractive efficiency is available because the major heat loss experienced in a 2 tank “indirect” system - losses by transferring the thermal energy from oil HTF to the salt storage material and back to oil to run the steam generator at night - is not present for the 2 tank direct system. The higher heat capacity values for both LMP and HMP systems enable larger storage capacities for concentrating solar power.

  11. Method to synthesize dense crystallized sodalite pellet for immobilizing halide salt radioactive waste

    DOEpatents

    Koyama, T.

    1992-01-01

    This report describes a method for immobilizing waste chloride salts containing radionuclides such as cesium and strontium and hazardous materials such as barium. A sodalite intermediate is prepared by mixing appropriate amounts of silica, alumina and sodium hydroxide with respect to sodalite and heating the mixture to form the sodalite intermediate and water. Heating is continued to drive off the water to form a water-free intermediate. The water-free intermediate is mixed with either waste salt or waste salt which has been contacted with zeolite to concentrate the radionuclides and hazardous material. The waste salt-intermediate mixture is then compacted and heated under conditions of heat and pressure to form sodalite with the waste salt, radionuclides and hazardous material trapped within the sodalite cage structure. This provides a final product having excellent leach resistant capabilities.

  12. Recyclization reactions of 1-alkylpyrimidinium salts

    PubMed Central

    Vardanyan, Ruben S.; Danagulyan, Gevork G.; Mkrtchyan, Armen D.; Hruby, Victor J.

    2014-01-01

    The reaction of 4-amino-2-benzyl-1-methyl-5-ethoxycarbonylpyrimidinium iodide (3) with alcoholic methylamine resulted in the formation of the methylimine of 2-amino-4-hydroxy-6-methylamino-5-phenylpyridine-3-carbaldehyde (5). Heating of the same pyrimidinium salt in benzylamine gave a mixture of products of two C–C recyclizations: 2-benzyl-4-benzylamino-5-carbamoylpyrimidine (7) and the benzylimine of 4-amino-2-benzyl-6-benzylaminopyrimidine-5-carbaldehyde (8). The reaction of 2-amino-1,4-dimethyl-5-ethoxycarbonylpyrimidinium iodide (10) with KOH ethanolic solution gave a single product of C–C-recyclization: 2-amino-5-acetyl-4-hydroxypyrimidine (11). PMID:25400328

  13. Amine salts of nitroazoles

    DOEpatents

    Kienyin Lee; Stinecipher, M.M.

    1993-10-26

    Compositions of matter, a method of providing chemical energy by burning said compositions, and methods of making said compositions are described. These compositions are amine salts of nitroazoles. 1 figure.

  14. Salt Plains Microbial Observatory

    NSDL National Science Digital Library

    Mark Buchheim

    This site is home of the Salt Plains Microbial Observatory, located in the Salt Plains National Wildlife Refuge in northern Oklahoma. This area has permitted the first extensive study of a non-marine, terrestrial, hypersaline environment. The web site offers information about the extreme environment, images and video clips of its microbial inhabitants, an image-rich summary of research activities, information about summer courses and research opportunities, a list of publications, and links to other informative resources pertaining to hypersaline environments.

  15. An experimental test plan for the characterization of molten salt thermochemical properties in heat transport systems

    SciTech Connect

    Pattrick Calderoni

    2010-09-01

    Molten salts are considered within the Very High Temperature Reactor program as heat transfer media because of their intrinsically favorable thermo-physical properties at temperatures starting from 300 C and extending up to 1200 C. In this context two main applications of molten salt are considered, both involving fluoride-based materials: as primary coolants for a heterogeneous fuel reactor core and as secondary heat transport medium to a helium power cycle for electricity generation or other processing plants, such as hydrogen production. The reference design concept here considered is the Advanced High Temperature Reactor (AHTR), which is a large passively safe reactor that uses solid graphite-matrix coated-particle fuel (similar to that used in gas-cooled reactors) and a molten salt primary and secondary coolant with peak temperatures between 700 and 1000 C, depending upon the application. However, the considerations included in this report apply to any high temperature system employing fluoride salts as heat transfer fluid, including intermediate heat exchangers for gas-cooled reactor concepts and homogenous molten salt concepts, and extending also to fast reactors, accelerator-driven systems and fusion energy systems. The purpose of this report is to identify the technical issues related to the thermo-physical and thermo-chemical properties of the molten salts that would require experimental characterization in order to proceed with a credible design of heat transfer systems and their subsequent safety evaluation and licensing. In particular, the report outlines an experimental R&D test plan that would have to be incorporated as part of the design and operation of an engineering scaled facility aimed at validating molten salt heat transfer components, such as Intermediate Heat Exchangers. This report builds on a previous review of thermo-physical properties and thermo-chemical characteristics of candidate molten salt coolants that was generated as part of the same project [1]. However, this work focuses on two materials: the LiF-BeF2 eutectic (67 and 33 mol%, respectively, also known as flibe) as primary coolant and the LiF-NaF-KF eutectic (46.5, 11.5, and 52 mol%, respectively, also known as flinak) as secondary heat transport fluid. At first common issues are identified, involving the preparation and purification of the materials as well as the development of suitable diagnostics. Than issues specific to each material and its application are considered, with focus on the compatibility with structural materials and the extension of the existing properties database.

  16. Low-transition-temperature mixtures (LTTMs): a new generation of designer solvents.

    PubMed

    Francisco, María; van den Bruinhorst, Adriaan; Kroon, Maaike C

    2013-03-11

    A new generation of designer solvents emerged in the last decade as promising green media for multiple applications, including separation processes: the low-transition-temperature mixtures (LTTMs). They can be prepared by mixing natural high-melting-point starting materials, which form a liquid by hydrogen-bond interactions. Among them, deep-eutectic solvents (DESs) were presented as promising alternatives to conventional ionic liquids (ILs). Some limitations of ILs are overcome by LTTMs, which are cheap and easy to prepare from natural and readily available starting materials, biodegradable, and renewable. PMID:23401138

  17. Thermal cycling effect on the nanoparticle distribution and specific heat of a carbonate eutectic with alumina nanoparticles

    E-print Network

    Shankar, Sandhya

    2011-08-08

    The objective of this research was to measure the effect of thermal cycling on the nanoparticle distribution and specific heat of a nanocomposite material consisting of a eutectic of lithium carbonate and potassium carbonate and 1% by mass alumina...

  18. Growth and microstructure evolution of the Nb{sub 2}Al-Al{sub 3}Nb eutectic in situ composite

    SciTech Connect

    Rios, C.T. [State University of Campinas, P.O. Box 6122, Campinas, SP 13083-970 (Brazil); Ferrandini, P.L. [Centro Universitario da FEI, C.P.85, CEP:09850-901, SP-Brasil (Brazil); Milenkovic, S. [State University of Campinas, P.O. Box 6122, Campinas, SP 13083-970 (Brazil); Caram, R. [State University of Campinas, P.O. Box 6122, Campinas, SP 13083-970 (Brazil)]. E-mail: rcaram@fem.unicamp.br

    2005-03-15

    In situ composite materials obtained by directional growth of eutectic alloys usually show improved properties, that make them potential candidates for high temperature applications. The eutectic alloy found in the Al-Nb system is composed of the two intermetallic phases Al{sub 3}Nb (D0{sub 22}) and Nb{sub 2}Al (D8{sub b}). This paper describes the directional solidification of an Al-Nb eutectic alloy using a Bridgman type facility at growth rates varying from 1.0 to 2.9 cm/h. Longitudinal and transverse sections of grown samples were characterized regarding the solidification microstructure by using optical and scanning electron microscopy, energy dispersive spectroscopy (EDS) and X-ray diffraction. Despite both phases being intermetallic compounds, the eutectic microstructure obtained was very regular. The results obtained were discussed regarding the effect of the growth rate on the microstructure, lamellar-rod transition and variation of phase volume fraction.

  19. A study of early corrosion behaviors of FeCrAl alloys in liquid lead–bismuth eutectic environments

    Microsoft Academic Search

    Jun Lim; Hyo On Nam; Il Soon Hwang; Ji Hyun Kim

    2010-01-01

    Lead and lead–bismuth eutectic (LBE) alloy have been increasingly receiving attention as heavy liquid metal coolants (HLMC) for future nuclear energy systems. The compatibility of structural materials and components with lead–bismuth eutectic liquid at high temperature is one of key issues for the commercialization of lead fast reactors. In the present study, the corrosion behaviors of iron-based alumina-forming alloys (Kanthal-AF®,

  20. Microstructures and hydrogen permeability of directionally solidified Nb–Ni–Ti alloys with the Nb–NiTi eutectic microstructure

    Microsoft Academic Search

    Kyosuke Kishida; Yuji Yamaguchi; Katsushi Tanaka; Haruyuki Inui; Sho Tokui; Kazuhiro Ishikawa; Kiyoshi Aoki

    2008-01-01

    The microstructures and hydrogen permeability properties were investigated for Nb–NiTi eutectic alloys directionally solidified in an optical floating zone furnace. Rod-type eutectic microstructures with Nb rods aligned parallel to the growth direction are obtained with an alloy having a composition of Nb–41Ni–40Ti grown at relatively slow growth rates below 2.5mm\\/h. The hydrogen permeability depends on the relative direction of aligned

  1. Crystallographically aligned metal-oxide composite made by reduction of a directionally solidified oxide-oxide eutectic

    Microsoft Academic Search

    A. Revcolevschi; G. Dhalenne

    1985-01-01

    Aligned metal-oxide composite materials have been grown from the melt by directional solidification at eutectic composition of several binary metal-oxide systems. The resulting microstructures consist of metallic fibres ~1 µm in diameter imbedded in an oxide matrix1,2. The occurrence of such fibrous structures, as opposed to lamellar structures, corresponds to eutectic compositions for which the volume fraction of the minor

  2. Microstructure characteristics and interface morphology evolvement of Si-TaSi 2 eutectic in situ composite for field emission

    Microsoft Academic Search

    Chunjuan Cui; Jun Zhang; Bo Li; Min Han; Lin Liu; Hengzhi Fu

    2007-01-01

    As one of the semiconductor-metal eutectic (SME) composites, Si-TaSi2 eutectic composite has many characters such as the high melting point of TaSi2 material, the large density of TaSi2 fibers incorporated into the Si matrix, three-dimensional array of Schottky junctions grown in the composite spontaneously. So it is an ideal candidate for field emission array cathodes. In this paper, the directionally

  3. Microstructure and mechanical behavior of in-situ directional solidified NiAl\\/Cr(Mo) eutectic composite

    Microsoft Academic Search

    J.-M. Yang; S. M. Jeng; K. Bain; R. A. Amato

    1997-01-01

    NiAl-based composites reinforced with refractory metals in-situ by the directional solidification technique have been recognized as promising candidate materials for high temperature structural applications. An in-situ NiAl\\/Cr(Mo) eutectic composite has been successfully fabricated using an edge-defined film-fed growth technique. The purpose of adding Mo into the NiAl\\/Cr eutectic system is to control the morphology of the Cr from a fibrous

  4. Salt Made the World Go Round: MRBLOCH Salt Archive

    NSDL National Science Digital Library

    Bloch, David.

    Don't you just love it when everything can be summed up with one simple explanantion? Created by David Bloch, this Website proves that life as we know depends upon salt. Sections of the site look at salt in relation to a wide range of areas of study, such as Physiology, Geology, Archaeology, Paleoclimatology, Religion, and Economics. For example, the Economics section provides information on the use of salt as money, the history of the control of salt by monopolies, and the influence of the salt trade on transportation. The Religion section points out the importance of salt in religious practices, such as Jewish koshering and Egyptian embalming. Also included are links to over fifty additional salt sites, an email list, and an announcement for Salt 2000, the 8th World Salt Symposium, to be held in the Hague in May 2000.

  5. A feasibility study of a diffusion barrier between Ni-Cr-Al coatings and nickel-based eutectic alloys

    NASA Technical Reports Server (NTRS)

    Young, S. G.; Zellars, G. R.

    1978-01-01

    Coating systems have been proposed for potential use on eutectic alloy components in high-temperature gas turbine engines. In a study to prevent the deterioration of such systems by diffusion, a tungsten sheet 25 microns thick was placed between eutectic alloys and an Ni-Cr-Al layer. Layered test specimens were aged at 1100 C for as long as 500 h. Without the tungsten barrier the delta phase of the eutectic deteriorated by diffusion of niobium into the Ni-Cr-Al. Insertion of the tungsten barrier stopped the diffusion of niobium from the delta phase. Chromium diffusion from the Ni-Cr-Al into the gamma/gamma-prime phase of the eutectic was greatly reduced by the barrier. However, the barrier thickness decreased with time, and tungsten diffused into both the Ni-Cr-Al and the eutectic. When the delta platelets were aligned parallel rather than perpendicular to the Ni-Cr-Al layer, diffusion into the eutectic was reduced.

  6. Carburetor mixture control apparatus

    SciTech Connect

    Dalke, A.E.

    1983-11-29

    A mixture control device is disclosed for automatically controlling the air to fuel mixture of a conventional carburetor involving a plurality of sloped radial vanes circumferentially located within the annulus formed by the booster venturi and the venturi tube. By inducing significant centrifugal motion in the air passing outside the booster venturi the problems associated with fuel to air mixture changes associated with changes in elevation and changes in seasonal temperatures are alleviated.

  7. In situ PM-IRRAS of a glassy carbon electrode/deep eutectic solvent interface.

    PubMed

    Vieira, Luciana; Schennach, Robert; Gollas, Bernhard

    2015-05-01

    The interface of a 1?:?2 molar choline chloride/ethylene glycol deep eutectic solvent with a glassy carbon electrode has been investigated by polarization modulation reflection-absorption spectroscopy (PM-IRRAS). Temporal spectral changes at open circuit potential show the experiments to be surface sensitive and indicate slow adsorption of electrolyte molecules on the electrode surface. In situ spectroelectrochemical PM-IRRAS measurements reveal characteristic potential-dependent changes of band intensities and wavenumber-shifts in the surface spectra. The potential dependent spectral changes are discussed in terms of adsorption, reduction, desorption and reorientation of choline cations at the interface. Analogies are drawn to the ionic layer structure proposed for the architecture of electrode/ionic liquid interfaces. The results show that in situ PM-IRRAS is generally applicable to glassy carbon electrodes and to electrode interfaces with deep eutectic solvents. PMID:25908481

  8. Relationship between edge drift and atomic migration during electromigration of eutectic SnPb lines

    NASA Astrophysics Data System (ADS)

    Yoon, Min-Seung; Lee, Shin-Bok; Kim, Oh-Han; Park, Young-Bae; Joo, Young-Chang

    2006-08-01

    The existence of an incubation stage before edge drift occurs was found by examining the electromigration characteristics of eutectic SnPb solder in an edge drift structure using in situ scanning electron microscopy and the interruptive test method. During this incubation stage, the depletion of Pb was observed at the cathode end. From the change in resistance, the activation energies for the incubation and edge movement stages were calculated to be 0.88 and 1.02eV, respectively. Based on a comparison of the activation energies for each stage with the previously reported values, it is believed that, during the incubation stage, Pb migrated before Sn and that the edge movement resulted from the migration of Sn. These results suggest that Pb depletion is a prerequisite for electromigration-induced void nucleation in eutectic SnPb solder.

  9. TEM/HREM structural characterization of directionally solidified GaAs-CrAs eutectic crystals

    SciTech Connect

    Ruvimov, S.; Liliental-Weber, Z.; Swider, W.; Washburn, J. [Lawrence Berkeley Lab., CA (United States). Material Science Div.; Holmes, D.E. [Electronic Materials Engineering, Camarillo, CA (United States)

    1996-12-31

    Conventional and high resolution electron microscopy have been applied to characterize the microstructure of the CrAs-GaAs eutectic. The CrAs-GaAs eutectic crystals were directionally solidified by the Czochralski method in order to produce an ordered array of CrAs rods embedded in a GaAs matrix. The CrAs rods of 2--3 {micro}m in diameter align parallel to the growth axis of the ingot. Where the GaAs matrix is found to contain structural defects, the CrAs rods are effectively defect-free. The CrAs has an orthorhombic structure with the parameters a = 3.5 {+-} 0.1 {angstrom}, b = 6.2 {+-} 0.1 {angstrom}, c = 5.7 {+-} 0.1 {angstrom}. The c-axis is close to the direction of solidification.

  10. Studies of directionally solidified eutectic Bi/MnBi at low growth velocities

    NASA Technical Reports Server (NTRS)

    Pirich, R. G.

    1984-01-01

    The (lambda-squared)(V) deviation for diffusion-only rod eutectic growth, where lambda is the interrod spacing and V is the growth velocity, was studied at growth velocities less than 5 cm/h in directionally solidified eutectic Bi-Mn (Bi/MnBi). At lower growth velocities, (V less than 0.5 cm/h) morphological instability occurred which resulted in nonaligned, irregularly dispersed MnBi fibers. The (lambda-squared)(V) relation was experimentally determined over a range of growth velocities between 0.1 and 50 cm/h, thermal gradients in the liquid at the liquid-solid interface that varied from 40 to 120 C/cm and solidification orientation with respect to the direction of gravity. Naturally induced, convective instabilities are suggested as a possible growth velocity limit for cooperative growth in the Bi-Mn and related alloy systems.

  11. High temperature oxidation resistant coatings for the directionally solidified Ni-Nb-Cr-Al eutectic superalloy

    NASA Technical Reports Server (NTRS)

    Strangman, T. E.; Ulion, N. E.; Felten, E. J.

    1977-01-01

    Protective coatings required for the Ni-Nb-Cr-Al directionally solidified eutectic superalloy were developed and evaluated on the basis of oxidation resistance, diffusional stability, thermal fatigue, and creep resistance. NiCrAlY+Pt and NiCrAlY physical vapor-deposition coating systems exhibited the best combination of properties. Burner-rig testing indicated that the useful life of a 127-micron-thick NiCrAlY+Pt coating exceeds 1000 h at 1366 K. Eutectic-alloy creep lives at 1311 K and a stress of 151.7 MN/sq m were greater for NiCrAlY+Pt-coated specimens than for uncoated specimens by a factor of two.

  12. Thermoelectric properties of Bi2Te3-PbTe pseudo binary near the eutectic composition.

    PubMed

    Jung, Kyooho; Jang, Ho Won; Kang, Chong-Yun; Yoo, Myong-Jae; Choi, Won Chel; Kim, Jin-Sang

    2012-04-01

    (Bi2Te3)(1-x)(PbTe)(x) binary systems near eutectic composition were prepared by melting of elemental metals and a sequential water quenching process and their microstructures and thermoelectric properties were investigated. Multiple phases such as Bi2Te3, BiPbTe and PbTe were observed due to phase separation when the composition x was higher than the eutectic point. Also the electrical conduction type of the alloys converted from p-type to n-type in the phase separated alloys. The lattice thermal conductivities in the phase-separated alloys are lower than those in alloys without phase separation, attributable to increased boundary scattering. PMID:22849153

  13. Fatigue of Ni-Ai-Mo aligned eutectics at elevated temperatures

    NASA Astrophysics Data System (ADS)

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

    1981-11-01

    The elevated-temperature mechanical behavior of two aligned eutectics (Ni-8.1 wt pct Al-26.4 wt pct Mo and Ni-6.3 wt pct Al-31.2 wt pct Mo) has been investigated utilizing monotonic and cyclic testing in vacuum. Tensile yield strength and fatigue resistance increased from 25 to 725 °C, but then were reduced at 825 °C. The fatigue lives of specimens tested at 725 °C decreased sharply with decreasing frequency. A shift from surface to internal crack initiation was observed upon increasing the test temperature from 725 to 825 °C. Stage II crack propagation was observed at both temperatures, in contrast to stage I cracking at 25 °C. The test results are compared to those for other nickel and cobalt-base aligned eutectics to show that the frequency effect on fatigue life is not limited to the Ni-AI-Mo system.

  14. Microstructural Effects on High Cycle Fatigue of Ni-AI-Mo Aligned Eutectics

    NASA Astrophysics Data System (ADS)

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

    1981-06-01

    Two nickel-base aligned eutectics, AG15 (Ni-8.1 wt pct Al-26.4 wt pct Mo) and AG34 (Ni-6.3 wt pct Al-31.2 wt pct Mo), have been tested in high cycle fatigue at room temperature. Experimental variables were test environment and post-solidification heat treatment. The fatigue lives of both alloys and the crack propagation resistance of AG15 improved substantially in tests performed in vacuum vs those performed in air. AG34 had a higher fatigue limit than AGI5; both alloys showed surface initiation and stage I crack propagation. Post-solidification heat treatment had a beneficial effect on the S-N lives of AG34 specimens. Fatigue resistance of both alloys is compared with that of other nickel or cobalt base eutectics strengthened with brittle fibers.

  15. Eutectic bonding of a Ti sputter coated, carbon aerogel wafer to a Ni foil

    SciTech Connect

    Jankowski, A.F.; Hayes, J.P.; Kanna, R.L.

    1994-06-01

    The formation of high energy density, storage devices is achievable using composite material systems. Alternate layering of carbon aerogel wafers and Ni foils with rnicroporous separators is a prospective composite for capacitor applications. An inherent problem exists to form a physical bond between Ni and the porous carbon wafer. The bonding process must be limited to temperatures less than 1000{degrees}C, at which point the aerogel begins to degrade. The advantage of a low temperature eutectic in the Ni-Ti alloy system solves this problem. Ti, a carbide former, is readily adherent as a sputter deposited thin film onto the carbon wafer. A vacuum bonding process is then used to join the Ni foil and Ti coating through eutectic phase formation. The parameters required for successfld bonding are described along with a structural characterization of the Ni foil-carbon aerogel wafer interface.

  16. Precipitation in aqueous mixtures with addition of a strongly hydrophilic or hydrophobic solute Ryuichi Okamoto and Akira Onuki

    E-print Network

    has been observed also in isobutylic acid IBA -water mixtures without added salt, where the isobutyric was observed in IBA-water for high contents of IBA 12 . Recently, mesophases have been observed when sodium

  17. SEPARATION AND PURIFICATION OF RARE EARTH ELEMENTS BY FRACTIONAL CRYSTALLIZATION. IV. PURIFICATIONS OF CERIUM GROUP ELEMENTS BY FRACTIONAL CRYSTALLIZATIONS OF DOUBLE SALTS OF NITRATES

    Microsoft Academic Search

    Shiokawa

    1963-01-01

    By fractional crystallizations of double salts of nitrates, binary ; mixtures of cerium-group elemen were purified. The samples of binary mixtures ; used in these experiments were ohtained by the fractional crystallization of ; double magnesium nitrate. In the purification of La and Pr from La- Pr mixture, ; the fractional crystallization of double ammonium nitrate was carried out using

  18. Compatibility of martensitic\\/austenitic steel welds with liquid lead bismuth eutectic environment

    Microsoft Academic Search

    J. Van den Bosch; A. Almazouzi

    2009-01-01

    The high-chromium ferritic\\/martensitic steel T91 and the austenitic stainless steel 316L are to be used in contact with liquid lead–bismuth eutectic (LBE), under high irradiation doses. Both tungsten inert gas (TIG) and electron beam (EB) T91\\/316L welds have been examined by means of metallography, scanning electron microscopy (SEM-EDX), Vickers hardness measurements and tensile testing both in inert gas and in

  19. Synthesis and Characterization of CuCl Nanoparticles in Deep Eutectic Solvents

    Microsoft Academic Search

    YING HUANG; FEI SHEN; JING LA; GENXIANG LUO; JUNLING LAI; CHUNSHENG LIU; GANG CHU

    2012-01-01

    In the present work, CuCl nanoparticles were fabricated in deep eutectic solvents (DES) which is a new kind of ionic liquid with special properties. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effect of polyvinylpyrrolidone (PVP), the molar ratio of ascorbic acid to copper chloride and the mixing method

  20. The kinetics of the Cu 2+\\/Cu + redox couple in deep eutectic solvents

    Microsoft Academic Search

    David Lloyd; Tuomas Vainikka; Lasse Murtomäki; Kyösti Kontturi; Elisabet Ahlberg

    2011-01-01

    Kinetics of electron transfer of the Cu(I)\\/Cu(II) redox couple at a platinum electrode has been studied with chronoamperometry, cyclic voltammetry and impedance spectroscopy in a deep eutectic solvent consisting of choline chloride and ethylene glycol. At 25°C, the reaction was found to be quasi-reversible with a relatively high rate constant k0 of 9.5±2×10?4cms?1, and a charge transfer coefficient ? of

  1. A novel green approach for the chemical modification of silica particles based on deep eutectic solvents.

    PubMed

    Gu, Tongnian; Zhang, Mingliang; Chen, Jia; Qiu, Hongdeng

    2015-06-01

    Deep eutectic solvents (DESs), as a novel class of green solvents, were successfully applied as eco-friendly and sustainable reaction media for fast surface modification of spherical porous silica, resulting in stationary phases for high-performance liquid chromatography. The new reaction media were advantageous over organic solvents in many aspects, such as the high dispersibility of silica spheres and their non-volatility. PMID:25985926

  2. Thermoelectric and morphological effects of peltier pulsing on directional solidification of eutectic Bi-Mn

    Microsoft Academic Search

    R. P. Silberstein; D. J. Larson; B. Dressler

    1984-01-01

    We have carried out extensivein situ thermal measurements during Peltier Interface Demarcation (PID) during directional solidification of eutectic Bi\\/MnBi. We\\u000a have observed that significant thermal transients occur throughout the sample as a result of the Peltier pulsing. We have\\u000a separated the contributions of the Peltier, Thomson, and Joule heats, and studied them as a function of pulse intensity and\\u000a polarity.

  3. Microstructure and creep of eutectic indium\\/tin on copper and nickel substrates

    Microsoft Academic Search

    J. L. Freer; J. W. Jr. Morris

    1992-01-01

    The behavior during creep in shear of eutectic indium-tin joints on copper and nickel substrates was examined in order to\\u000a determine the effect of creep deformation on the microstructure of the alloy. Primary creep was absent in all the samples\\u000a tested. The stress exponent at 20° C was much higher for samples on nickel than for those on copper, indicating

  4. The effect of heat transfer on local solidification kinetics of eutectic Al-Si cast alloy

    Microsoft Academic Search

    C. González-Rivera; M. H. Cruz; H. A. García; J. A. Juarez-Islas

    1999-01-01

    Recently, Fourier thermal analysis (FTA) has been proposed as a suitable technique to obtain information about local solidification\\u000a kinetics in casting alloys. In this work, FTA was applied to a near-eutectic aluminum-silicon cast alloy in order to seek\\u000a experimental evidence supporting the solidification kinetics obtained from this method. Also, a heat-transfer\\/solidification-kinetics\\u000a model was used to compare predictions with experimental results.

  5. Damage by eutectic particle cracking in aluminum casting alloys A356\\/357

    Microsoft Academic Search

    Q. G. Wang; C. H. Caceres; J. R. Griffiths

    2003-01-01

    The strain dependence of particle cracking in aluminum alloys A356\\/357 in the T6 temper has been studied in a range of microstructures\\u000a produced by varying solidification rate and Mg content, and by chemical (Sr) modification of the eutectic silicon. The damage\\u000a accumulates linearly with the applied strain for all microstructures, but the rate depends on the secondary dendrite arm spacing

  6. Interlamellar residual stresses in single grains of NiO-ZrOâ(cubic) directionally solidified eutectics

    Microsoft Academic Search

    Elizabeth C. Dickey; Vinayak P. Dravid; Camden R. Hubbard

    1997-01-01

    Phase-to-phase residual stresses due to thermal expansion mismatch were measured in lamellar NiO-ZrOâ (cubic) directionally solidified eutectics (DSEs). The triaxial strain tensors for both phases were measured using single-crystal X-ray diffractometry techniques on isolated grains of the DSE. From the strain tensors, the stress tensors were calculated, taking into account the full elastic anisotropy of the phases. The resulting stress

  7. Structured porous Ni and Co-YSZ cermets fabricated from directionally solidified eutectic composites

    Microsoft Academic Search

    M. A. Laguna-Bercero; A. Larrea; J. I. Peña; R. I. Merino; V. M. Orera

    2005-01-01

    NiO-YSZ and CoO-YSZ eutectic rods were produced by directional solidification using the laser floating zone method (LFZ). This technique produces highly structured material consisting of alternate lamellae of transition metal oxide and zirconia with variable interlamellar spacing depending on growth conditions. We have chosen conditions for interlamellar spacing of about 1?m. The microstructure is homogeneous and mechanically stable during thermochemical

  8. Stability of the directionally solidified eutectics NiAl-Cr and NiAl-Mo

    Microsoft Academic Search

    J. L. Walter; H. E. Cline

    1973-01-01

    The eutectics NiAl-Cr with cylindrical chromium fibers and NiAl-Mo with faceted molybdenum fibers were heated at 1400?C to\\u000a determine the stability of the composite structure and to compare the stability of the nonfaceted fibers with that of the\\u000a faceted fibers in the NiAl matrix. Fiber size and size distribution and number of fibers per unit area were measured as a

  9. Microstructures and mechanical properties of a directionally solidified NiAl–Mo eutectic alloy

    Microsoft Academic Search

    H.. Bei; E. P.. George

    2005-01-01

    A NiAl–Mo ternary eutectic alloy, having the nominal composition Ni–45.5Al–9Mo (at.%), was directionally solidified in a high-temperature optical floating zone furnace. Well-aligned rod-like microstructures were obtained, consisting of NiAl matrix and 14% (by volume) continuous Mo fibers having a square cross-section. With increasing growth rate (from 20 to 80 mm\\/h), the spacing and size of the Mo fibers decreased, from

  10. Mechanical behavior of a carbide reinforced Co-Cr eutectic alloy

    Microsoft Academic Search

    E. R. Thompson; D. A. Koss; J. C. Chesnutt

    1970-01-01

    The tensile and creep behavior of a unidirectionally solidified (Co, Cr)-(Cr, Co)7C3 monovariant eutectic alloy have been examined. The effect of fiber orientation on the tensile strength has been studied at temperatures to 2200°F. The composite was found to be anisotropic with considerable strengthening in the longitudinal direction and with the transverse and 45 deg ultimate strengths being limited by

  11. The influence of electric current pulses on the microstructure of the MnBi\\/Bi eutectic

    Microsoft Academic Search

    F. Li; L. L. Regel; W. R. Wilcox

    2001-01-01

    The MnBi\\/Bi eutectic was directionally solidified with freezing rate oscillations caused by electric current pulses. The influence of current pulsing on microstructure depended on the ampoule translation rate V and pulsing conditions. Continuous electric current had a small effect on the microstructure. Current pulsing with the solid positive had a substantial influence, greater than with the solid negative. For V?2cm\\/h,

  12. Structure and magnetic properties of directionally solidified Bi-MnBi eutectic alloys

    Microsoft Academic Search

    M. R. Notis; D. M. Shah; S. Young; C. Graham

    1979-01-01

    An alloy containing about 2 at% Mn and 98 at% Bi should solidify at 230°C to give a eutectic consisting of about 3 vol % ferromagnetic MnBi in a matrix of diamagnetic Bi. Directional solidification of this alloy produces a structure of elongated parallel MnBi rods with diameters from 0.1 to 1.5 ?m, decreasing with increasing growth rate. Samples solidified

  13. Determination of phase diagrams of eutectic binary alloys with partial solid solubility

    Microsoft Academic Search

    L. J. Gallego; J. A. Somoza; J. A. Alonso; J. M. Lopez

    1988-01-01

    Using a semi-empirical theory largely based on the heat of formation model developed by Miedema and co-workers, we have constructed the phase diagram of the alloy CuAg, a prototypical example of a system of eutectic type with appreciable solid solubility and no intermetallic compounds. This is an advance on the simpler kind of phase diagrams we considered in a previous

  14. High temperature ultrasonic transducers for imaging and measurements in a liquid Pb\\/Bi eutectic alloy

    Microsoft Academic Search

    Rymantas Kazys; Algirdas Voleisis; Reimondas Sliteris; Liudas Mazeika; Rudi Van Nieuwenhove; Peter Kupschus; Hamid Ait Abderrahim

    2005-01-01

    In some nuclear reactors or accelerator-driven systems (ADS) the core is intended to be cooled by means of a heavy liquid metal, for example, lead-bismuth (Pb\\/Bi) eutectic alloy. For safety and licensing reasons, an imaging method of the interior of ADS, based on application of ultrasonic waves, has thus to be developed. This paper is devoted to the description of

  15. Eutectic bonding of austenitic stainless steel 316L to magnesium alloy AZ31 using copper interlayer

    Microsoft Academic Search

    Waled M. Elthalabawy; Tahir I. Khan

    2011-01-01

    The eutectic bonding of magnesium alloy (AZ31) to austenitic stainless steel alloy (316L) was performed using pure Cu interlayers.\\u000a The effect of hold time on the microstructural developments across the joint region and the related effect on bond shear strength\\u000a were studied at a bonding temperature of 530°C. The bonding process took place through a sequential occurrence of solid-state\\u000a diffusion

  16. Selective Au-Si eutectic bonding for Si-based MEMS applications

    SciTech Connect

    Lee, A.; Lehew, S.; Yu, C. [and others

    1995-05-22

    A novel method of fabricating three-dimensional silicon micro electromechanical systems (MEMS) is presented, using selectivity thin film deposited Au-Si eutectic bond pads. Utilizing this process, complicated structures such as microgrippers and microchannels are fabricated. Bond strengths are higher than the silicon fracture strength and the bond areas can be localized and aligned to the processed wafer. The process and the applications are described in this paper.

  17. Corrosion of metals in molten lithium sulphate-potassium sulphate eutectic

    Microsoft Academic Search

    G. M. Abou-Elenien

    1991-01-01

    In conjunction with the development of a new electrochemical flue gas desulphurization process, a study is made of the corrosion of several electrode materials in molten lithium sulphate-potassium sulphate eutectic at 600°C. Measurements of the open-circuit potentials are made in air, oxygen and nitrogen to determine the existence of a stable oxide layer on the electrode surface. Voltammetric measurements are

  18. High cycle fatigue of tantalum carbide reinforced nickel base eutectics at room temperature

    Microsoft Academic Search

    D. E. Graham; D. A. Woodford

    1979-01-01

    The high cycle fatigue response of two advanced tantalum carbide strengthened eutectic superalloys has been determined at\\u000a room temperature. Since these alloys will be coated in service, the effects of variables associated with coating processes\\u000a were given special attention. Both alloys showed a well defined fatigue limit. It was concluded that the maximum stress obtained\\u000a in the cycle at the

  19. Unidirectional solidification of Al–Cu eutectic with the accelerated crucible rotation technique

    Microsoft Academic Search

    D. Ma; W. Q Jie; W Xu; Y Li; S Liu

    1998-01-01

    The accelerated crucible rotation technique (ACRT) has been applied to the unidirectional solidification of Al–Cu eutectic to reveal the effect of forced convection on the solidification microstructures by a systematic experimental investigation combining different rotation methods (the maximum rotation rate ?max=100–400rpm) with various growth velocities (V0=5–60?m\\/s). The results can be concluded as follows: (1)Forced convection introduced by ACRT dramatically changes

  20. The thermal expansion of the directionally solidified AI-CuAI2 eutectic

    Microsoft Academic Search

    Dennis F. Baker; Robert H. Bragg

    1981-01-01

    Alloys of Al-CuAl2 eutectic composition were prepared from 99.999 pct pure materials and directionally solidified in a temperature gradient of about 45 °C\\/cm at different growth rates R. The lambda2R = constant relation was verified and lamellar spacings of 7.5, 3.5, 2.6, 1.8 and 1.4 mum were obtained. Dilatometer specimens were machined with axes aligned in the principal lamellae coordinate

  1. Banding formation and eutectic lamellar growth in directional solidified Ni 50 Al 20 Fe 30 alloy

    Microsoft Academic Search

    J. Chen; J. H. Lee; Y. T. Lee; Z. Q. Hut

    1998-01-01

    Banding formation and eutectic lamellar growth in a directionally solidified Ni50Al20Fe30 alloy were investigated. It was found that the banding area consists of two layers. The first layer is a ? layer, while the\\u000a subsequent one is a ? layer. The composition of various phases around the banding area changes with the solidification process.\\u000a The banding is formed by two

  2. Thermal Stability of FeS2 Cathode Material in "Thermal" Batteries: Effect of Dissolved Oxides in Molten Salt Electrolytes

    NASA Astrophysics Data System (ADS)

    Masset, Patrick J.

    2008-09-01

    The thermal stability of FeS2 cathode material for thermal batteries is investigated in the LiCl-KCl eutectic containing up to 10 wt% Li2O (used as anti-peak). The results show that the decomposition of pyrite shifts to higher temperatures in the presence of molten salts as the S2 gas is repressed by the liquid phase. For high lithium oxide contents the decomposition temperature of pyrite decreases by 100 °C. In addition Li2FeS2 as reaction product is evidenced whereas Li3Fe2S4 is expected from literature data.

  3. A high temperature molten salt thermal electrochemical cell

    NASA Astrophysics Data System (ADS)

    Plichta, Edward J.; Behl, Wishvender K.

    1990-02-01

    This invention relates in general to a high temperature molten salt thermal electrochemical cell and in particular to such a cell including cobalt oxide (Co3O4) as the cathode material. High temperature molten salt thermal electrochemical cells are widely used as power sources for projectiles, rockets, bombs, mines, missiles, decoys, jammers, and torpedoes. These are also used as fuses. Thermal electrochemical cells are reserve-type cells that can be activated by heating with a pyrotechnic heat source such as zirconium and barium chromate powders or mixtures of iron powder and potassium perchlorate.

  4. High-temperature molten-salt thermal electrochemical cell

    SciTech Connect

    Plichta, E.J.; Behl, W.K.

    1990-02-12

    This invention relates in general to a high temperature molten salt thermal electrochemical cell and in particular to such a cell including cobalt oxide (Co{sub 3}O{sub 4}) as the cathode material. High temperature molten salt thermal electrochemical cells are widely used as power sources for projectiles, rockets, bombs, mines, missiles, decoys, jammers and torpedoes. These are also used as fuses. Thermal electrochemical cells are reserve-type cells that can be activated by heating with a pyrotechnic heat source such as zirconium and barium chromate powders or mixtures of iron powder and potassium perchlorate.

  5. A New Co-C Eutectic Fixed-Point Cell for Thermocouple Calibration at

    NASA Astrophysics Data System (ADS)

    Failleau, G.; Deuzé, T.; Jouin, D.; Mokdad, S.; Briaudeau, S.; Sadli, M.

    2014-07-01

    The eutectic Co-C is a promising system to serve as a thermometric fixed point beyond the freezing point of copper (). Some national metrology institutes have developed, characterized, and compared their Co-C fixed-point cells based on conventional designs. Indeed, the fixed-point cells constructed are directly inspired by the technologies applied to the fixed points of the ITS-90 to the lower levels of temperature. By studying the eutectic metal-carbon systems, is appears that the high temperatures of implementation give a set of difficulties, such as the strong mechanical stresses on the graphite crucibles, due to the important thermal expansion of the eutectic alloys during their phase transitions. If these devices are suitable with research activities to serve like primary standards, it is not envisaged to propose them for a direct application to the calibration activities for the industry. As regards the limited robustness of the conventional fixed-point cells constructed, an intensive use of these device would not be reasonable, in term of cost for example. In this paper, a new Co-C fixed-point design is introduced. This low cost device has been developed specifically for intensive use in thermocouple calibration activities, with the aim of achieving the lowest level of uncertainties as is practicable. Thus, in this paper, the metrological characterization of this device is also presented, and a direct comparison to a primary Co-C fixed-point cell previously constructed is discussed.

  6. Brazing characteristics of a Zr-Ti-Cu-Fe eutectic alloy filler metal for Zircaloy-4

    NASA Astrophysics Data System (ADS)

    Lee, Jung G.; Lim, C. H.; Kim, K. H.; Park, S. S.; Lee, M. K.; Rhee, C. K.

    2013-10-01

    A Zr-Ti-Cu-Fe quaternary eutectic alloy was employed as a new Be-free brazing filler metal for Zircaloy-4 to supersede physically vapor-deposited Be coatings used conventionally with several disadvantages. The quaternary eutectic composition of Zr58Ti16Cu10Fe16 (at.%) showing a low melting temperature range from 832 °C to 853 °C was designed by a partial substitution of Zr with Ti based on a Zr-Cu-Fe ternary eutectic system. By applying an alloy ribbon with the determined composition, a highly reliable joint was obtained with a homogeneous formation of predominantly grown ?-Zr phases owing to a complete isothermal solidification, exhibiting strength higher than that of Zircaloy-4. The homogenization of the joint was rate-controlled by the diffusion of the filler elements (Ti, Cu, and Fe) into the Zircaloy-4 base metal, and the detrimental segregation of the Zr2Fe phase in the central zone was completely eliminated by an isothermal holding at a brazing temperature of 920 °C for 10 min.

  7. Natural deep eutectic solvents as a new extraction media for phenolic metabolites in Carthamus tinctorius L.

    PubMed

    Dai, Yuntao; Witkamp, Geert-Jan; Verpoorte, Robert; Choi, Young Hae

    2013-07-01

    Developing green solvents with low toxicity and cost is an important issue for the biochemical industry. Synthetic ionic liquids and deep eutectic solvents have received considerable attention due to their negligible volatility at room temperature, high solubilization ability, and tunable selectivity. However, the potential toxicity of the synthetic ionic liquids and the solid state at room temperature of most deep eutectic solvents hamper their application as extraction solvents. In this study, a wide range of recently discovered natural ionic liquids and deep eutectic solvents (NADES) composed of natural compounds were investigated for the extraction of phenolic compounds of diverse polarity. Safflower was selected as a case study because its aromatic pigments cover a wide range of polarities. Many advantageous features of NADES (such as their sustainability, biodegradability combined with acceptable pharmaceutical toxicity profiles, and their high solubilization power of both polar and nonpolar compounds) suggest their potential as green solvents for extraction. Experiments with different NADES and multivariate data analysis demonstrated that the extractability of both polar and less polar metabolites was greater with NADES than conventional solvents. The water content in NADES proved to have the biggest effect on the yield of phenolic compounds. Most major phenolic compounds were recovered from NADES with a yield between 75% and 97%. This study reveals the potential of NADES for applications involving the extraction of bioactive compounds from natural sources. PMID:23710664

  8. A New Analytical Approach to Predict Spacing Selection in Lamellar and Rod Eutectic Systems

    NASA Technical Reports Server (NTRS)

    Catalina, Adrian V.; Sen, Subhayu; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    In this paper, we reexamine the Jackson and Hunt (JH) theory and relax the assumption of isothermal solid/liquid interface(SLI) used in their treatment. A modification of the term B. in the expression of the solute concentration profile is also proposed. Based on the predictions of this modified theory the traditional definitions of regular and irregular eutectics are discussed. For regular eutectics the new model identifies a range of spacing within the limits defined by the minimum undercooling of the alpha and beta phase. For the irregular Al-Si eutectic system in particular we identified two different spacing selection mechanisnis: a) for a particular growth rate, a nearly isothermal interface can be achieved at a unique minimum spacing lambda(sub I); b) the average spacing in the microstructure (lambda(sub av) > lambda(sub I)) is essentially dictated by the undercooling of the faceted phase. Based on the modified theoretical model a semi-empirical expression has been developed to account for the influence of the temperature gradient. The theoretical calculations have been found to be in good agreement with the published experimental measurements.

  9. Influence of gravity driven convection on the directional solidification of Bi/MnBi eutectic composites

    NASA Technical Reports Server (NTRS)

    Pirich, R. G.; Larson, D. J.

    1982-01-01

    The role of gravity on Bridgman-Stockharger directional solidification of eutectic Bi/MnBi has been studied in reduced gravity aboard NASA sounding rocket SPAR flight experiments and contrasted with normal gravity investigations. The directional solidification of eutectic Bi/MnBi results in a low volume fraction, faceted/nonfaceted aligned rod eutectic whose MnBi rod size, interrod spacing, thermal and magnetic properties are sensitive functions of solidification processing conditions. The morphology of the low-gravity samples showed striking differences compared with identically processed, normal gravity samples grown in the same apparatus. The MnBi rod diameter and interrod spacing distributions were significantly smaller, approximately 50 percent, for the low gravity samples compared with identically processed one gravity samples. Accompanying the smaller MnBi rod diameters observed in the flight samples, was an increase in permanent magnet properties which reached greater than 97 percent of the theoretical maximum. Gravitationally induced thermal instabilities in one-gravity which result in irregular interface movement and associated difficulty of the faceted MnBi phase to branch are suggested to explain the morphological differences between one and low gravity solidification.

  10. Feasibility study of tungsten as a diffusion barrier between nickel-chromium-aluminum and Gamma/Gamma prime - Delta eutectic alloys

    NASA Technical Reports Server (NTRS)

    Young, S. G.; Zellars, G. R.

    1978-01-01

    Coating systems proposed for potential use on eutectic alloy components in high-temperature gas turbine engines were studied with emphasis on deterioration of such systems by diffusion. A 1-mil thick W sheet was placed between eutectic alloys and a NiCrAl layer. Layered test specimens were aged at 1100 C for as long as long as 500 hours. Without the W barrier, the delta phase of the eutectic deteriorated by diffusion of Nb into the NiCrAl. Insertion of the W barrier stopped the diffusion of Nb from delta. Chromium diffusion from the NiCrAl into the gamma/gamma prime phase of the eutectic was greatly reduced by the barrier. However, the barrier thickness decreased with time; and W diffused into both the NiCrAl and the eutectic. When the delta platelets were alined parallel to the NiCrAl layer, rather than perpendicular, diffusion into the eutectic was reduced.

  11. Concentration and precipitation of NaCl and KCl from salt cake leach solutions by electrodialysis

    SciTech Connect

    Sreenivasarao, K; Patsiogiannis, F.; Hryn, J.N.

    1997-02-09

    Electrodialysis was investigated for cost-effective recovery of salt from salt cake leach solutions. (Salt cake is a waste stream generated by the aluminum industry during treatment of aluminum drosses and scrap.) We used a pilot-scale electrodialysis stack of 5 membrane pairs, each with an effective area of 0.02 m{sup 2}. The diluate stream contained synthetic NaCl, KCl,mixtures of NaCl and KCl, and actual salt cake leach solutions (mainly NaCl and KCl, with small amounts of MgCl{sub 2}). We concentrated and precipitated NaCl and KCl salts from the concentrate steam when the initial diluate stream concentration was 21.5 to 28.8 wt% NaCl and KCl. We found that water transferring through the membranes was a significant factor in overall efficiency of salt recovery by electrodialysis.

  12. Microstructural characterization of a directionally-solidified Ni–33 (at.%) Al–31Cr–3Mo eutectic alloy as a function of withdrawal rate

    Microsoft Academic Search

    S. V. Raj; I. E. Locci

    2001-01-01

    The Ni–33 (at.%)Al–31Cr–3Mo eutectic alloy was directionally-solidified (DS) at different rates, VI, varying between 2.5 to 508 mm h?1. Detailed qualitative and quantitative metallographic and chemical analyses were conducted on the directionally-solidified rods. The microstructures consisted of eutectic colonies with parallel lamellar NiAl\\/(Cr,Mo) plates for solidification rates at and below 12.7 mm h?1. Cellular eutectic microstructures were observed at higher

  13. Processing, Microstructures, and Properties of Cr-Cr3Si, Nb-Nb3Si, and V-V3Si Eutectics

    Microsoft Academic Search

    B. P. Bewlay; J. A. Sutliff; M. R. Jackson; K. M. Chang

    1994-01-01

    The present paper examines the potential of refractory metal-A15 silicide composites as structural materials for high temperature applications. Three eutectic systems are considered, Cr-Cr3Si, Nb-Nb3Si, and V-V3Si, since they all have melting points above 1700°C and densities lower than Ni-based superalloys. Eutectic compositions were selected because directional solidification of eutectics can be used to generate aligned composite microstructures. The present

  14. Messin' with Mixtures

    NSDL National Science Digital Library

    2014-09-18

    In this activity, students investigate the properties of a heterogeneous mixture, trail mix, as if it were a contaminated soil sample near a construction site. This activity shows students that heterogeneous mixtures can be separated by physical means, and that when separated, all the parts will equal the whole.

  15. The Nature of Salt

    NSDL National Science Digital Library

    This is a hands-on lab activity about the composition of salt. Learners will explain the general relationship between an element's Periodic Table Group Number and its tendency to gain or lose electron(s), and explain the difference between molecular compounds and ionic compounds. They will then use household materials to build a model to demonstrate sodium chloride's cubic form and describe the nature of the electrostatic attraction that holds the structure of salt together. Background information, common preconceptions, a glossary and more is included. This activity is part of the Aquarius Hands-on Laboratory Activities.

  16. Near azeotropic mixture substitute

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    1996-01-01

    The present invention comprises a refrigerant mixture consisting of a first mole fraction of 1,1,1,2-tetrafluoroethane (R134a) and a second mole fraction of a component selected from the group consisting of a mixture of CHClFCF.sub.3 (R124) and CH.sub.3 CClF.sub.2 (R142b); a mixture of CHF.sub.2 CH.sub.3 (R152a) and CHClFCF.sub.3 (R124); a mixture of CHF.sub.2 CH.sub.3 (R152a) and CH.sub.3 CClF.sub.2 (R142b); and a mixture of CHClFCF.sub.3 (R124), CH.sub.3 CClF.sub.2 (R142b) and CHF.sub.2 CH.sub.3 (R152a).

  17. Actinide removal from spent salts

    DOEpatents

    Hsu, Peter C. (Pleasanton, CA); von Holtz, Erica H. (Livermore, CA); Hipple, David L. (Livermore, CA); Summers, Leslie J. (Livermore, CA); Adamson, Martyn G. (Danville, CA)

    2002-01-01

    A method for removing actinide contaminants (uranium and thorium) from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents are added to precipitate the thorium as thorium oxide and/or the uranium as either uranium oxide or as a diuranate salt. The precipitated materials are filtered, dried and packaged for disposal as radioactive waste. About 90% of the thorium and/or uranium present is removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration <20% require further clean-up using an ion exchange column, which yields salt solutions that contain less than 0.1 ppm of thorium or uranium.

  18. Metals removal from spent salts

    DOEpatents

    Hsu, Peter C. (Pleasanton, CA); Von Holtz, Erica H. (Livermore, CA); Hipple, David L. (Livermore, CA); Summers, Leslie J. (Livermore, CA); Brummond, William A. (Livermore, CA); Adamson, Martyn G. (Danville, CA)

    2002-01-01

    A method and apparatus for removing metal contaminants from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents may be added to precipitate the metal oxide and/or the metal as either metal oxide, metal hydroxide, or as a salt. The precipitated materials are filtered, dried and packaged for disposal as waste or can be immobilized as ceramic pellets. More than about 90% of the metals and mineral residues (ashes) present are removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be spray-dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration <20% require further clean-up using an ion exchange column, which yields salt solutions that contain less than 1.0 ppm of contaminants.

  19. Microstructural development and mechanical behavior of eutectic bismuth-tin and eutectic indium-tin in response to high temperature deformation

    SciTech Connect

    Goldstein, J.L.F. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering; [Lawrence Berkeley Lab., CA (United States)

    1993-11-01

    The mechanical behavior and microstructure of eutectic Bi-Sn and In-Sn solders were studied in parallel in order to better understand high temperature deformation of these alloys. Bi-Sn solder joints were made with Cu substrates, and In-Sn joints were made with either Cu or Ni substrates. The as-cast microstructure of Bi-Sn is complex regular, with the two eutectic phases interconnected in complicated patterns. The as-cast microstructure of In-Sn depends on the substrate. In-Sn on Cu has a non-uniform microstructure caused by diffusion of Cu into the solder during sample preparation, with regions of the Sn-rich {gamma} phase imbedded in a matrix of the In-rich {beta} phase. The microstructure of In-Sn on Ni is uniform and lamellar and the two phases are strongly coupled. The solders deform non-uniformly, with deformation concentrating in a band along the length of the sample for Bi-Sn and In-Sn on Cu, though the deformation is more diffuse in In-Sn than in Bi-Sn. Deformation of In-Sn on Ni spreads throughout the width of the joint. The different deformation patterns affect the shape of the stress-strain curves. Stress-strain curves for Bi-Sn and In-Sn on Cu exhibit sharp decays in the engineering stress after reaching a peak. Most of this stress decay is removed for In-Sn on Ni. The creep behavior of In-Sn also depends on the substrate, with the creep deformation controlled by the soft P phase of the eutectic for In-Sn on Cu and controlled by the harder {gamma} phase for In-Sn on Ni. When In-Sn on Ni samples are aged, the microstructure coarsens and changes to an array of {gamma} phase regions in a matrix of the {beta} phase, and the creep behavior changes to resemble that of In-Sn on Cu. The creep behavior of Bi-Sn changes with temperature. Two independent mechanisms operate at lower temperatures, but there is still some question as to whether one or both of these, or a third mechanism, operates at higher temperatures.

  20. Avi's Sensational Salt Dough

    NSDL National Science Digital Library

    American Chemical Society

    2006-01-01

    In this activity on page 5 of the PDF, learners mimic the process for making bricks. Learners shape and bake creations from a dough that is made from flour, salt, and water. Use this activity to introduce learners to chemical changes. Safety notes: Follow Milli's safety notes (on page 2) and do this activity with an adult.