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1

Molecular to ionic transition of BiCl3 in LiCl KCl eutectic melt  

NASA Astrophysics Data System (ADS)

The local structures of molten BiCl3 and its mixtures in LiCl KCl eutectic melt were investigated by X-ray absorption fine structure (XAFS) technique. The first Bi Cl correlation in molten pure BiCl3 shows covalent nature, since the distance was almost the same as sum of the covalent radii of Bi and Cl and the coordination number was almost 3. The similar property was also observed in the mixture of 75% BiCl3 with LiCl KCl eutectic melt. Drastic change was detected in 25% BiCl3 mixture melt. The first Bi Cl distance was the sum of the ionic radii in molten 25% BiCl3 melt. The results suggest that BiCl3 changes from molecular liquid to ionic by mixing with alkali chlorides.

Okamoto, Yoshihiro; Yaita, Tsuyoshi; Minato, Kazuo

2005-07-01

2

Electrochemical behaviors of PuN and (U, Pu)N in LiCl KCl eutectic melts  

NASA Astrophysics Data System (ADS)

Electrochemical behaviors of PuN and (U, Pu)N in the LiCl KCl eutectic melts at 773 K were investigated by cyclic voltammetry. The electrochemical dissolution of PuN and (U, Pu)N began nearly at -0.900.05 and -0.950.05 V (vs. Ag+/Ag), respectively. The rest potentials of PuN and (U, Pu)N were observed at about 0.15 V more negative potential than that of UN, in the present experimental condition. The observed rest potentials of (U, Pu)N depended on the equilibrium potential of the Pu3+/PuN. In the cyclic voltammogram measured by use of (U, Pu)N as the working electrode, a steep rise of the positive current was observed at potentials more positive than -0.45 V in analogy with the cyclic voltammogram measured by use of UN as the working electrode. These indicate that UN and PuN in (U, Pu)N would be dissolved independently irrespective of forming the solid solution.

Shirai, O.; Kato, T.; Iwai, T.; Arai, Y.; Yamashita, T.

2005-02-01

3

Thermochemical properties of lanthanides (Ln = La, Nd) and actinides (An = U, Np, Pu, Am) in the molten LiCl KCl eutectic  

NASA Astrophysics Data System (ADS)

The electrochemical reduction of actinides (U, Pu, Np and Am) and lanthanides (La and Nd) chlorides was investigated by cyclic voltammetry and chronopotentiometry at different temperatures in LiCl KCl eutectic. The diffusion coefficients of these metallic cations were estimated as well as their apparent standard potentials. These values of potentials are compared with existing data measured also by transient electrochemical techniques or e.m.f. measurements.

Masset, Patrick; Konings, Rudy J. M.; Malmbeck, Rikard; Serp, Jrme; Glatz, Jean-Paul

2005-09-01

4

Determination of uranium and rare-earth metals separation coefficients in LiCl KCl melt by electrochemical transient techniques  

NASA Astrophysics Data System (ADS)

The main step in the pyrometallurgical process of spent nuclear fuel recycling is a molten salt electrorefining. The knowledge of separation coefficients of actinides (U, Np, Pu and Am) and rare-earth metals (Y, La, Ce, Nd and Gd) is very important for this step. Usually the separation coefficients are evaluated from the formal standard potentials of metals in melts containing their own ions, values obtained by potentiometric method. Electrochemical experiments were carried out at 723 823 K in order to estimate separation coefficients in LiCl KCl eutectic melt containing uranium and lanthanum trichlorides. It was shown that for the calculation of uranium and lanthanum separation coefficients it is necessary to determine the voltammetric peak potentials of U(III) and La(III), their concentration in the melt and the kinetic parameters relating to U(III) discharge such as transfer and diffusion coefficients, and standard rate constants of charge transfer.

Kuznetsov, S. A.; Hayashi, H.; Minato, K.; Gaune-Escard, M.

2005-09-01

5

Separation of plutonium from lanthanum by electrolysis in LiCl KCl onto molten bismuth electrode  

NASA Astrophysics Data System (ADS)

This work presents a study on the electroseparation of plutonium from lanthanum using molten bismuth electrodes in LiCl KCl eutectic at 733 K. The reduction potentials of Pu3+ and La3+ ions were measured on a Bi thin film electrode using cyclic voltammetry (CV). A difference between the peak potentials for the formation of PuBi2 and LaBi2 of approximately 100 mV was found. Separation tests were then carried out using different current densities and salt phase compositions between a plutonium rod anode and an unstirred molten Bi cathode in order to evaluate the efficiency of an electrolytic separation process. At a current density of 12 mA/cm2/wt% (Pu3+), only Pu3+ ions are reduced into the molten Bi electrode, leaving La3+ ions in the salt melt. Similar results were found at two different Pu/La concentration ratios ([Pu]/[La] = 4 and 10). At a current density of 26 mA/cm2/wt% (Pu3+), co-reduction of Pu and La was observed as expected by the large negative potential of the Bi cathode during the separation test.

Serp, J.; Lefebvre, P.; Malmbeck, R.; Rebizant, J.; Vallet, P.; Glatz, J.-P.

2005-04-01

6

Molten salt eutectics from atomistic simulations  

Microsoft Academic Search

Despite their importance for solar thermal power applications, phase-diagrams of molten salt mixture heat transfer fluids (HTFs) are not readily accessible from first principles. We present a molecular dynamics scheme general enough to identify eutectics of any HTF candidate mixture. The eutectic mixture and temperature are located using the liquid mixture free energy and the pure component solid-liquid free energy

Saivenkataraman Jayaraman; Aidan P. Thompson; O. Anatole von Lilienfeld

2011-01-01

7

Catalytic gasification of coal using eutectic salts: identification of eutectics  

Microsoft Academic Search

Different eutectic salt mixture catalysts for the gasification of Illinois No. 6 coal were identified and various impregnation or catalyst addition methods to improve catalyst dispersion were evaluated in this study. In addition, the effects of major process variables such as temperature, pressure, and steam\\/carbon ratio were investigated in a thermogravimetric analyzer (TGA) and fixed-bed bench scale reactor systems. The

Yaw D Yeboah; Yong Xu; Atul Sheth; Anuradha Godavarty; Pradeep K Agrawal

2003-01-01

8

Molten salt eutectics from atomistic simulations  

NASA Astrophysics Data System (ADS)

Despite their importance for solar thermal power applications, phase-diagrams of molten salt mixture heat transfer fluids (HTFs) are not readily accessible from first principles. We present a molecular dynamics scheme general enough to identify eutectics of any HTF candidate mixture. The eutectic mixture and temperature are located using the liquid mixture free energy and the pure component solid-liquid free energy differences. The liquid mixture free energy is obtained using thermodynamic integration over particle identity transmutations sampled with molecular dynamics at a single temperature. Drawbacks of conventional phase diagram mapping methodologies are avoided by not considering solid mixtures, thereby evading expensive computations of solid phase free energies. Numerical results for binary and ternary mixtures of alkali nitrates agree well with experimental measurements.

Jayaraman, Saivenkataraman; Thompson, Aidan P.; von Lilienfeld, O. Anatole

2011-09-01

9

CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES  

Microsoft Academic Search

The project, ''Catalytic Gasification of Coal Using Eutectic Salt Mixtures'', is being conducted jointly by Clark Atlanta University (CAU), the University of Tennessee Space Institute (UTSI) and the Georgia Institute of Technology (GT). The aims of the project are to: identify appropriate eutectic salt mixture catalysts for the gasification of Illinois No.6 coal; evaluate various impregnation or catalyst addition methods

1999-01-01

10

Separation of Pure LiCl-KCl Eutectic Salt from a Mixture of LiCl-KCl Eutectic Salt and Rare-Earth Precipitates by Vacuum Distillation  

Microsoft Academic Search

In this study, the vacuum distillation of LiCl-KCl eutectic salt in a mixture of LiCl-KCl eutectic salt and rare-earth precipitates was carried out to evaluate the vaporization characteristics of LiCl-KCl eutectic salt. It was confirmed that the required time for salt vaporization was reduced by a reduction in the pressure. It appeared that the vaporization of LiCl-KCl eutectic salt containing

Hee-Chul EUN; Hee-Chul YANG; Yong-Jun CHO; Hwan-Seo PARK; Eung-Ho KIM; In-Tae KIM

2007-01-01

11

CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES  

SciTech Connect

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

NONE

2000-04-01

12

CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES  

SciTech Connect

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

NONE

1998-10-01

13

Catalytic Gasification of Coal using Eutectic Salt Mixtures.  

National Technical Information Service (NTIS)

The objectives of this study are 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; eva...

Atul Sheth Pradeep Agrawal Yaw D. Yeboah

1998-01-01

14

Catalytic Gasification of Coal using Eutectic Salt Mixtures  

SciTech Connect

The objectives of this study are 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; 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. A review of the collected literature was carried out. The catalysts which have been used for gasification can be roughly classified under the following five groups: alkali metal salts; alkaline earth metal oxides and salts; mineral substances or ash in coal; transition metals and their oxides and salts; and eutectic salt mixtures. Studies involving the use of gasification catalysts have been conducted. However, most of the studies focused on the application of individual catalysts. Only two publications have reported the study of gasification of coal char in CO2 and steam catalyzed by eutectic salt mixture catalysts. By using the eutectic mixtures of salts that show good activity as individual compounds, the gasification temperature can be reduced possibly with still better activity and gasification rates due to improved dispersion of the molten catalyst on the coal particles. For similar metal/carbon atomic ratios, eutectic catalysts were found to be consistently more active than their respective single salts. But the exact roles that the eutectic salt mixtures play in these are not well understood and details of the mechanisms remain unclear. The effects of the surface property of coals and the application methods of eutectic salt mixture catalysts with coal chars on the reactivity of gasification will be studied. Based on our preliminary evaluation of the literature, a ternary eutectic salt mixture consisting of Li- Na- and K- carbonates has the potential as gasification catalyst. To verify the literature reported, melting points for various compositions consisting of these three salts and the temperature range over which the mixture remained molten were determined in the lab. For mixtures with different concentrations of the three salts, the temperatures at which the mixtures were found to be in complete molten state were recorded. By increasing the amount of Li2CO3, the melting temperature range was reduced significantly. In the literature, the eutectic mixtures of Li- Na- and K-carbonates are claimed to have a lower activation energy than that of K2CO3 alone and they remain molten at a lower temperature than pure K2CO3. The slow increase in the gasification rates with eutectics reported in the literature is believed to be due to a gradual penetration of the coals and coal char particles by the molten and viscous catalyst phase. The even spreading of the salt phase seems to increase the overall carbon conversion rate. In the next reporting period, a number of eutectic salts and methods of their application on the coal will be identified and tested.

Atul Sheth; Pradeep Agrawal; Yaw D. Yeboah

1998-12-04

15

Catalytic gasification of coal using eutectic salts: reaction kinetics with binary and ternary eutectic catalysts  

Microsoft Academic Search

Kinetic studies of the catalytic steam gasification of Illinois No. 6 coal were carried out using binary and ternary eutectic salt mixtures in a fixed-bed reactor. The effects of major process variables such as temperature, pressure, catalyst loading and steam flow rate were evaluated for the binary 29% Na2CO371% K2CO3 and ternary 43.5% Li2CO331.5% Na2CO325% K2CO3 eutectic catalyst systems. A

Atul Sheth; Yaw D. Yeboah; Anuradha Godavarty; Yong Xu; Pradeep K. Agrawal

2003-01-01

16

Catalytic Gasification of Coal using Eutectic Salt Mixtures  

Microsoft Academic Search

The objectives of this study are 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; 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

Atul Sheth; Pradeep Agrawal; Yaw D. Yeboah

1998-01-01

17

CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES  

SciTech Connect

This is the progress report for the DOE grant DE-FG26-97FT97263 entitled, ''Catalytic Gasification of Coal Using Eutectic Salt Mixtures'' for the period April 1999 to October 1999. The project is being conducted jointly by Clark Atlanta University, the University of Tennessee Space Institute and Georgia Institute of Technology. The overall objectives of the project are 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; evaluate effects of major process variables (such as temperature and system pressure) on coal gasification; evaluate the recovery, regeneration and recycle of the spent catalysts; and conduct thorough analysis and modeling of the gasification process to provide better understanding of the fundamental mechanisms and kinetics of the process. During this reporting period, free swelling index measurements of the coal, fixed-bed gasification experiments, kinetic modeling of the catalyzed gasification, and X-ray diffraction analysis of catalyst and gasified char samples were undertaken. The gasification experiments were carried out using two different eutectic salt mixtures of Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3}-K{sub 2}CO{sub 3} (LNK) system and Na{sub 2}CO{sub 3}-K{sub 2}CO{sub 3} (NK) system. The gasification process followed a Langmuir-Hinshelwood type model. At 10 wt% of catalyst loading, the activation energy of the ternary catalyst system (LNK) was about half (98kJ/mol) the activation energy of the single catalyst system (K{sub 2}CO{sub 3}), which is about 170 kJ/ mole. The binary catalyst system (NK) showed activation energy of about 201 kJ/mol, which is slightly higher, compared to the K{sub 2}CO{sub 3} catalyst system. The ternary catalyst system was a much better eutectic catalyst system compared to the binary or single catalyst system. In general, a eutectic with a melting point less than the gasification temperature is a better substitute to the single alkali metal salts because they have good catalyst distribution and dispersion in the carbon matrix. The free selling index of the coal was about 1.5 (1 to 2) in comparison to 2.5 (2 to 3) for the coal samples with ternary eutectic. The results for the raw coal were consistent with those from the Penn State Coal Bank. The XRD characterization showed unidentified peaks in the spectra of some of the samples and require further studies to draw any conclusions at the point.

NONE

1999-10-01

18

Modeling of anodic dissolution of U Pu Zr ternary alloy in the molten LiCl KCl electrolyte  

NASA Astrophysics Data System (ADS)

The metallic fuel anode in the molten salt electrorefining step for the pyrometallurgical reprocessing was modeled based on the findings from the anodic dissolution tests using a U Pu Zr ternary alloy. This anode model simulates selective dissolution of uranium and plutonium at lower anode potential, growth of a diffusion controlling layer consisting of a mixture of the molten salt electrolyte and the remaining zirconium metal, and simultaneous dissolution of all the constituents at higher anode potential. The calculation with this model reproduced well the actual anodic behavior of the U Pu Zr ternary alloy such as two-step rapid rise in the anode potential.

Iizuka, Masatoshi; Kinoshita, Kensuke; Koyama, Tadafumi

2005-02-01

19

Effect of inorganic salts on crystallization of poly(ethylene glycol) in frozen solutions.  

PubMed

The effect of inorganic salts on eutectic crystallization of poly(ethylene glycol) (PEG) 1500-20,000 in frozen solution was studied to model the polymer and inorganic salt interaction in freeze-dried formulations. Thermal analysis of an aqueous PEG 3000 solution showed a eutectic PEG crystallization exotherm at approximately -47 degrees C and a subsequent PEG crystal melting endotherm at -14.9 degrees C. Addition of sodium chloride prevented the PEG crystallization in the freeze-concentrated solution surrounding ice crystals. Higher concentration NaCl was required to retain higher molecular weight PEG in the amorphous state. Various inorganic salts prevented the PEG crystallization to varying degrees depending mainly on the position of the anion in the Hofmeister's lyotropic series. Some salting-in and 'intermediate' salts (NaSCN, NaI, NaBr, NaCl, LiCl, KCl, and RbCl) inhibited the crystallization of PEG 7500 in frozen solutions. On the other hand, salting-out salts (NaH2PO4, Na2HPO4, Na2SO4, and NaF) did not show an apparent effect on the PEG crystallization. Some salting-out salts induced PEG crystallization in PEG and sucrose combination frozen solutions. The varying abilities of salts to prevent the PEG crystallization in frozen solutions strongly suggested that the solutes had different degrees of miscibility in the freeze-concentrates. PMID:15607262

Izutsu, Ken-ichi; Aoyagi, Nobuo

2004-11-11

20

CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES  

SciTech Connect

The project, ''Catalytic Gasification of Coal Using Eutectic Salt Mixtures'', is being conducted jointly by Clark Atlanta University (CAU), the University of Tennessee Space Institute (UTSI) and the Georgia Institute of Technology (GT). The aims of the project are to: identify appropriate eutectic salt mixture catalysts for the gasification of Illinois No.6 coal; evaluate various impregnation or catalyst addition methods to improve catalyst dispersion; evaluate effects of major process variables (e.g., temperature, system pressure, etc.) on coal gasification; evaluate the recovery, regeneration and recycle of the spent catalysts in a bench-scale fixed bed reactor; and conduct thorough analysis and modeling of the gasification process to provide a better understanding of the fundamental mechanisms and kinetics of the process. The eutectic catalysts increased gasification rate significantly. The methods of catalyst preparation and addition had significant effect on the catalytic activity and coal gasification. The incipient wetness method gave more uniform catalyst distribution than that of physical mixing for the soluble catalysts resulting in higher gasification rates for the incipient wetness samples. The catalytic activity increased by varying degrees with catalyst loading. The above results are especially important since the eutectic catalysts (with low melting points) yield significant gasification rates even at low temperatures. Among the ternary eutectic catalysts studied, the system 39% Li{sub 2}CO{sub 3}-38.5% Na{sub 2}CO{sub 3}-22.5% Rb{sub 2}CO{sub 3} showed the best activity and will be used for further bench scale fixed-bed gasification reactor in the next period. Based on the Clark Atlanta University studies in the previous reporting period, the project team selected the 43.5% Li{sub 2}CO{sub 3}-31.5% Na{sub 2}CO{sub 3}-25% K{sub 2}CO{sub 3} ternary eutectic and the 29% Na{sub 2}CO{sub 3}-71% K{sub 2}CO{sub 3} binary eutectic for the fixed-bed studies at UTSI during this reporting period. Temperature was found to have a significant effect on the rate of gasification of coal. The rate of gasification increased up to 1400 F. Pressure did not have much effect on the gasification rates. The catalyst loading increased the gasification rate and approached complete conversion when 10 wt% of catalyst was added to the coal. Upon further increasing the catalyst amount to 20-wt% and above, there was no significant rise in gasification rate. The rate of gasification was lower for a 2:1 steam to char molar ratio (60%) compared to gasification rates at 3.4:1 molar ratio of steam-to-char where the conversion approached 100%. The characterization results of Georgia Tech are very preliminary and inconclusive and will be made available in the next report.

Unknown

1999-04-01

21

Compatibility of Inconel 617 alloy with eutectic fluoride salts at high temperatures  

Microsoft Academic Search

Thermal Energy Storage (TES) capsules made of Inconel 617 alloy were filled with high purity eutectic fluoride salts and thermally cycled at eutectic temperature +\\/-100 K for a period of up to 50,000 hours. The containment life performance characteristics with fluoride salts were examined. The depletion of Al and Cr near the inner edges was found. Atomic Absorption Spectroscopy revealed

Anhua Luo; Dean L. Jacobson; Rengasamy Ponnappan

1993-01-01

22

Assessment of Plant Toxicity Threshold of Several Heat Transfer and Storage Fluids and Eutectic Salts.  

National Technical Information Service (NTIS)

Plant toxicity threshold levels of several heat transfer and storage fluids and eutectic salts were determined by using a modified Neubauer technique. Barley seed germination and seedling growth were used for the toxicity tests. The general order of toxic...

H. Nishita

1980-01-01

23

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

Microsoft Academic Search

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

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

2009-01-01

24

CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES  

SciTech Connect

Most of the tasks on the project have successfully been completed and reported. A 12 month no-cost extension has been requested to complete the remaining tasks. This report summarizes the accomplishments of the first six months of the no-cost extensions period. The acetic acid extraction showed that acetic acid has more effect on the extraction of the ternary catalyst (LNK) ions than water. Based on the extraction results, the order of the recovery capability of Na{sub 2}CO{sub 3} using acetic acid, sulfuric acid and water extractions is sulfuric acid {ge} acetic acid > water; the order for K{sub 2}CO{sub 3} is sulfuric acid > water >acetic acid; and the order for Li{sub 2}CO{sub 3} is acetic acid > sulfuric acid >water. A process flowsheet for the catalyst recovery process was proposed based on the results. Scanning electron microscopy (SEM) studies showed most of the particles (coal) appear amorphous. Some coal particles are as large as 50-60 {micro}m, but most are smaller. One can also easily see a few crystalline particles (10-20 {micro}m) with sharp facets and corners. The electron micrographs of gasified char samples (reactor-aged) of the LNKcoal mixture showed that a dramatic change is obvious in the morphology and crystallinity of the sample and is consistent with the results obtained from the x-ray diffraction studies. XRD studies of reactor-aged samples showed a substantial increase in the sample crystallinity (due to the gasification of amorphous carbon). The eutectic salt presumably mostly converted to sulfates.

Atul Sheth; Chandramouli Sastry

2001-03-31

25

The enthalpy of occlusion of the (lithium chloride + potassium chloride) eutectic salt in zeolite 4A  

Microsoft Academic Search

The molar enthalpy of occlusion of the (lithium chloride + potassium chloride) eutectic salt in zeolite 4A at the salt melting temperature ?occHm(Tfus) was measured using differential scanning calorimetry. It was found that up to a mole fraction of the salt x= 0.931 in the (salt + zeolite) mixture, which is near the expected zeolite occlusion limit, ?occHm(Tfus) was negative

Dusan Lexa

1999-01-01

26

Aerosol thermodynamics of potassium salts, double salts, and water content near the eutectic  

NASA Astrophysics Data System (ADS)

Water uptake by hygroscopic constituents of atmospheric particles has implications for climate and health. This article focuses on three topics related to calculating particle water uptake. First, an electrodynamic balance (EDB) is used to measure water activity for supersaturated binary KNO 3 and KCl solutions. The EDB measurements for KNO 3 confirm earlier predictions, while those for KCl confirm earlier measurements. Second, our earlier theory for the variation in mutual deliquescence relative humidity (MDRH) with temperature ( T) is extended to double salt systems. The MDRH( T) equation for double salt systems reduces to the earlier equation under some conditions, and predictions for two systems are in reasonable agreement with solubility-based calculations. Finally, an approximate treatment of water uptake in the MDRH region (i.e., near the eutectic) is evaluated, and a new approach is developed that accounts for particle composition. The new approach represents predictions of a benchmark model well and eliminates most of the error associated with the earlier method. Although simple treatments of water uptake near the eutectic may introduce error into equilibrium calculations, their use can sometimes be justified based on inherent limitations of aerosol representations in chemistry-transport models. Results of this study can be used to improve calculations of water content in atmospheric aerosol models.

Kelly, James T.; Wexler, Anthony S.; Chan, Chak K.; Chan, Man N.

27

Eutectic Salt Catalyzed Environmentally Benign and Highly Efficient Biginelli Reaction  

PubMed Central

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.

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

2012-01-01

28

Eutectic salt catalyzed environmentally benign and highly efficient Biginelli reaction.  

PubMed

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

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

2012-04-29

29

Catalytic Gasification of Coal Using Eutectic Salts: Recovery, Regeneration, and Recycle of Spent Eutectic Catalysts  

Microsoft Academic Search

Catalyst recovery studies were conducted for gasified chars produced from steam gasification of Illinois #6 coal catalyzed with two different catalyst systems. A ternary (43.5 mol% Li2 CO3 31.5 mol% Na2 CO3 25 mol% K2 CO3 ) and a binary (29 mol% Na2 CO3 71 mol% K2 CO3 ) eutectic catalyst system were used for gasifying coal. Various extraction schemes,

Atul C. Sheth; Chandramouli Sastry; Yaw D. Yeboah; Yong Xu; Pradeep Agarwal

2003-01-01

30

Materials corrosion in molten lithium fluoride-sodium fluoride-potassium fluoride eutectic salt  

Microsoft Academic Search

Static corrosion studies were undertaken to determine the compatibility of several candidate high temperature materials for a heat transfer loop in a molten alkali fluoride eutectic salt, LiF-NaF-KF: 46.5-11.5-42 mol % (commonly referred to as FLiNaK), as well as a molten chloride near eutectic salt, KCl-MgCl2: 68-32 mol %. Several high temperature alloys: Hastelloy-N, Hastelloy-X, Haynes-230, Inconel-617, and Incoloy-800H, Nb-1Zr,

Luke Christopher Olson

2009-01-01

31

Electrolysis of uranium nitride containing fission product elements (Mo, Pd, Nd) in a molten LiCl-KCl eutectic  

SciTech Connect

The electrolysis of burnup-simulated uranium nitride, UN, containing representative solid fission product elements (Mo, Pd, Nd) was investigated in the molten LiCl-KCl eutectic salt with 0.54 wt% UCl{sub 3} from the view point of application of pyrochemical reprocessing to nitride fuel cycle. It was found from cyclic voltammetry and anodic polarization curve measurement that anodic dissolution of UN began at about -0.75 V vs. Ag/AgCl reference electrode in all samples. After the electrolysis at the constant anodic potential of -0.65 {approx} -0.60 V vs. Ag/AgCl, most of UN was dissolved into LiCl- KCl as UCl{sub 3} at the anode, and U was recovered in the liquid Cd cathode in all samples. Further, Nd was dissolved into LiCl-KCl as NdCl{sub 3}, while Mo and Pd were not dissolved but remained at the anode. (authors)

Satoh, Takumi; Iwai, Takashi; Arai, Yasuo [Japan Atomic Energy Agency, Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki-ken, 311-1393 (Japan)

2007-07-01

32

Study on room heating utilizing eutectic salt mixture  

Microsoft Academic Search

Through studies of phase change between solid and liquid, an inorganic eutectic mixture, Mg(NO3)2-6H2O\\/MgCl2-6H2O has been developed as a heat storage material. Using this mixture, a room heating system involving a heat storage tank and a simple solar collector has been studied; the feasibility of such a system has been evaluated; and problems which will be encountered in the course

N. Yoneda; S. Takanashi

1978-01-01

33

Design and implementation of an eutectic salt cooling energy storage system for load management  

Microsoft Academic Search

An air conditioner system with 1800 RT-HR eutectic salt energy storage tank was built for the demonstration of the cooling energy storage (CES) system. Six operation modes are designed to meet different cooling load requirements. By computer simulation, it was found that 38.7% of the electric peak demand has been reduced and 37% of the energy consumption has been shifted

C. S. Chen; J. N. Sheen

1991-01-01

34

Assessment of plant toxicity threshold of several heat transfer and storage fluids and eutectic salts  

Microsoft Academic Search

Plant toxicity threshold levels of several heat transfer and storage fluids and eutectic salts were determined by using a modified Neubauer technique. Barley seed germination and seedling growth were used for the toxicity tests. The general order of toxicity of the fluids applied to three mineral soils was ethylene gloycol > Dow 200 much greater than Caloria HT43 > Therminol

Nishita

1980-01-01

35

Synthesis of Ni 3Al intermetallic powder in eutectic molten salts  

Microsoft Academic Search

The powders of Ni3Al intermetallic compounds were simply and economically synthesized by the chemical reaction in the various molten salts systems. In the relatively low temperature ranges, we studied to synthesize Ni3Al intermetallic powders from Al and NiCl2 in five kinds of eutectic molten salts by varying the reaction time and mole ratio of reactants. Ni3Al intermetallic powders could be

Hyun-Suk Choo; Kwan-Young Lee; Yun-Sung Kim; Jung-Ho Wee

2005-01-01

36

Stabilization of rare earth nuclides in LiCl-KCl eutectic salt wastes  

Microsoft Academic Search

Distillation and condensation characteristics of LiCl-KCl eutectic salts containing rare earth precipitates were investigated\\u000a and a conversion of the rare earth oxychlorides to oxides was performed. The distillation flux was increased by about 1,000\\u000a times by reducing the pressure from 760 Torr to 0.5 Torr. The composition of the recovered salts was changed according to\\u000a the condensed spot. The conversion

H. C. Eun; H. C. Yang; Y. Z. Cho; H. S. Park; H. S. Lee; I. T. Kim

2009-01-01

37

Distillation and condensation of LiClKCl eutectic salts for a separation of pure salts from salt wastes from an electrorefining process  

Microsoft Academic Search

Salt separation and recovery from the salt wastes generated from a pyrochemical process is necessary to minimize the high-level waste volumes and to stabilize a final waste form. In this study, the thermal behavior of the LiClKCl eutectic salts containing rare earth oxychlorides or oxides was investigated during a vacuum distillation and condensation process. LiCl was more easily vaporized than

Hee Chul Eun; Hee Chul Yang; Han Soo Lee; In Tae Kim

2009-01-01

38

Heat storage containers filled with the combination of a eutectic salt and a non-biodegradable filler material  

SciTech Connect

A heat storage article adapted for prevention of stratification of heat storage materials, such as eutectic salts contained within the container element. The article is comprised of a heavy thermally conductive container with an internal cavity. The internal cavity of the container is substantially completely filled with a combination of a non-biodegradable filler material such as glass fiber insulation and a eutectic salt.

Schoenfelder, J.L.

1980-09-23

39

Electrodeposition Characteristics of Uranium in Molten LiCl-KCl Eutectic and its Salt Distillation Behavior  

Microsoft Academic Search

Electrorefining experiments with a crucial anode containing U, elemental rare earths; Gd, Nd and Ce or Nd2O3 were carried out in KCL-LiCL eutectic melt at 500C. Partitioning behavior of the components according to the applied voltage or current was investigated at various initial U concentrations in a molten salt. Elemental REs concentrations in the cathode deposits increased as the applied

Jong-Hyeon LEE; Young-Ho KANG; Sung-Chan HWANG; Joon-Bo SHIM; Byung-Gil AHN; Eung-Ho KIM; Seong-Won PARK

2006-01-01

40

Study on the distillation rates of LiClKCl eutectic salt under different vacuum conditions  

Microsoft Academic Search

A study on the distillation rate of LiClKCl eutectic salt under different vacuums from 0.5 to 50Torr was performed by using thermogravimetric (TG) method. A distillation rate of the order of 10?410?5molcm?2s?1 was obtainable at temperatures of 12001300K and vacuums of 550Torr. Based on the non-isothermal TG data, model distillation flux equations could be derived as a function of temperature.

H.-C. Yang; H.-C. Eun; I.-T. Kim

2009-01-01

41

Catalytic oxidation of methane over KCl-LnCl 3 eutectic molten salts  

Microsoft Academic Search

The study of the partial oxidation of methane (POM) over KCl-LnCl3 (Ln=La, Ce, Sm, Dy, Yb) eutectic molten salts was undertaken. The reaction main products were hydrocarbons (primarily C2, selectivity >70%). The formation of hydrogen was never detected. The catalytic performance is clearly dependent on the rare earth ions properties and the factors that seem to contribute to the variation

Joaquim B. Branco; Gonalo Lopes; Ana C. Ferreira

2011-01-01

42

Recycling of LiCl-KCl eutectic based salt wastes containing radioactive rare earth oxychlorides or oxides  

NASA Astrophysics Data System (ADS)

Recycling of LiCl-KCl eutectic salt wastes containing radioactive rare earth oxychlorides or oxides was studied to recover renewable salts from the salt wastes and to minimize the radioactive wastes by using a vacuum distillation method. Vaporization of the LiCl-KCl eutectic salt was effective above 900 C and at 5 Torr. The condensations of the vaporized salt were largely dependent on temperature gradient. Based on these results, a recycling system of the salt wastes as a closed loop type was developed to obtain a high efficiency of the salt recovery condition. In this system, it was confirmed that renewable salt was recovered at more than 99 wt.% from the salt wastes, and the changes in temperature and pressure in the system could be utilized to understand the present condition of the system operation.

Eun, H. C.; Cho, Y. Z.; Son, S. M.; Lee, T. K.; Yang, H. C.; Kim, I. T.; Lee, H. S.

2012-01-01

43

Purification of used eutectic (LiCl-KCl) salt electrolyte from pyroprocessing  

NASA Astrophysics Data System (ADS)

The separation characteristics of surrogate rare-earth fission products in a eutectic (LiCl-KCl) molten salt were investigated. This system is based on the eutectic salt used for the pyroprocessing treatment of used nuclear fuel (UNF). The investigation was performed using an integrated rare-earth separation apparatus comprising a precipitation reactor, a solid detachment device, and a layer separation device. To separate rare-earth fission products, a phosphate precipitation method using both Li3PO4 and K3PO4 as a precipitant was performed. The use of an equivalent phosphate precipitant composed of 0.408 molar ratio-K3PO4 and 0.592 molar ratio-Li3PO4 can preserve the original eutectic ratio, LiCl-0.592 molar ratio (or 45.2 wt%), as well as provide a high separation efficiency of over 99.5% under conditions of 550 C and Ar sparging when using La, Nd, Ce, and Pr chlorides. The mixture of La, Nd, Ce, and Pr phosphate had a typical monoclinic (or monazite) structure, which has been proposed as a reliable host matrix for the permanent disposal of a high-level waste form. To maximize the reusability of purified eutectic waste salt after rare-earth separation, the successive rare-earth separation process, which uses both phosphate precipitation and an oxygen sparging method, were introduced and tested with eight rare-earth (Y, La, Ce, Pr, Nd, Sm, Eu and Gd) chlorides. In the successive rare-earth separation process, the phosphate reaction was terminated within 1 h at 550 C, and a 4-8 h oxygen sparging time were required to obtain over a 99% separation efficiency at 700-750 C. The mixture of rare-earth precipitates separated by the successive rare-earth separation process was found to be phosphate, oxychloride, and oxide. Through the successive rare-earth separation process, the eutectic ratio of purified salt maintained its original value, and impurity content including the residual precipitant of purified salt can be minimized.

Cho, Yung-Zun; Lee, Tae-Kyo; Eun, Hee-Chul; Choi, Jung-Hoon; Kim, In-Tae; Park, Geun-Il

2013-06-01

44

Separation behaviors of actinides from rare-earths in molten salt electrorefining using saturated liquid cadmium cathode  

NASA Astrophysics Data System (ADS)

Electrorefining in the molten LiCl KCl eutectic salt containing actinide (An) and rare-earth (RE) elements was conducted to recover An elements up to 10 wt% into liquid cadmium (Cd) cathode, which is much higher than the solubility of the An elements in liquid Cd at the experimental temperature of 773 K. In the saturated Cd cathode, the An and RE elements were recovered forming a PuCd11 type compound, MCd11 (M = An and RE elements). The separation factors of element M against Pu defined as [M/Pu in Cd alloy (cathode)]/[M/Pu in molten salt] were calculated for the saturated Cd cathode including MCd11. The separation factors were 0.011, 0.044, 0.064, and 0.064 for La, Ce, Pr, and Nd, respectively. These values were a little differed from 0.014, 0.038, 0.044, and 0.043 for the equilibrium unsaturated liquid Cd, respectively. The above slight differences were considered to be caused by the solid phase formation in the saturated Cd cathode and the electrochemical transfer of the An and RE elements in the molten salt.

Kato, Tetsuya; Inoue, Tadashi; Iwai, Takashi; Arai, Yasuo

2006-10-01

45

Eutectics and Phase Diagrams of Molten Salts from Molecular Dynamics simulations  

NASA Astrophysics Data System (ADS)

The use of alkali nitrate salt mixtures as heat transfer fluids in solar thermal power plants is limited by their relatively high melting point. Certain compositions of quaternary and higher dimensional mixtures of alkali and alkaline earth nitrates and nitrites have low melting points. However, the high dimensionality of the search space makes it difficult to find lowest melting compositions. Molecular simulations offer an efficient way to screen for promising mixtures. A molecular dynamics scheme general enough to identify eutectics of any HTF candidate mixture will be presented. The eutectic mixture and temperature are located as the tangent point between free energies of mixing for the liquid and a linear plane connecting the pure solid-liquid free energy differences. The free energy of mixing of the liquid phase is obtained using thermodynamic integration over "alchemical" transmutations sampled with molecular dynamics, in which particle identities are swapped gradually. Numerical results for binary and ternary mixtures of alkali nitrates agree well with experimental measurements.

Jayaraman, Saivenkataraman; von Lilienfeld, Anatole; Thompson, Aidan

2011-03-01

46

Compatibility of Inconel 617 alloy with eutectic fluoride salts at high temperatures  

NASA Astrophysics Data System (ADS)

Thermal Energy Storage (TES) capsules made of Inconel 617 alloy were filled with high purity eutectic fluoride salts and thermally cycled at eutectic temperature +/-100 K for a period of up to 50,000 hours. The containment life performance characteristics with fluoride salts were examined. The depletion of Al and Cr near the inner edges was found. Atomic Absorption Spectroscopy revealed that both Al and Cr were dissolved in the fluoride salts at high temperatures. The changes in melting temperature and heat of fusion of fluoride salts during thermal cycling were measured with Thermal Differential Analysis. A modified diffusion equation for a one-dimensional semi-infinite bar was applied to the depletion of Al on the interior surfaces of the containers. Good agreement was obtained between the analysis and the measured concentration profiles. The present study suggests that the corrosion was a diffusion controlled process and an expected lifetime of 5-7 years is reasonable and predictable based upon the limited diffusion processes.

Luo, Anhua; Jacobson, Dean L.; Ponnappan, Rengasamy

1993-01-01

47

Assessment of plant toxicity threshold of several heat transfer and storage fluids and eutectic salts  

SciTech Connect

Plant toxicity threshold levels of several heat transfer and storage fluids and eutectic salts were determined by using a modified Neubauer technique. Barley seed germination and seedling growth were used for the toxicity tests. The general order of toxicity of the fluids applied to three mineral soils was ethylene gloycol > Dow 200 much greater than Caloria HT43 > Therminol 66. The toxicity order of the fluids applied to an organic soil was ethylene glycol > Caloria HT43 > Dow 200 > Therminol 66. Thus, Therminol 66 was the least toxic among the fluids used. Among the eutectic salts tested Dupont HITEC was more toxic than 8.4 percent NaCl-86.3 percent NaNO/sub 3/-5.3 percent Na/sub 2/SO/sub 4/ mixture in three of the four soils used. In the fourth soil there was no apparent difference of toxicity between the two salt mixtures. Depending on the fluid and the salt mixture, the toxicity threshold levels for barley seedlings ranged from 4451 to 317,488 ppM in the soils used.

Nishita, H.

1980-10-01

48

The enthalpy of occlusion of the LiC1KC1 eutectic salt in zeolite 4A  

Microsoft Academic Search

The molar enthalpy of occlusion of the (lithium chloride + potassium chloride) eutectic salt in zeolite 4A at the salt melting temperature {sub 9cc}H{sub m}(T{sub fus}) was measured using differential scanning calorimetry. It was found that up to a mole fraction of the salt x = 0.931 in the (salt + zeolite) mixture, which is near the expected zeolite occlusion

D. Lexa

1999-01-01

49

The enthalpy of occlusion of the LiC1-KC1 eutectic salt in zeolite 4A.  

SciTech Connect

The molar enthalpy of occlusion of the (lithium chloride + potassium chloride) eutectic salt in zeolite 4A at the salt melting temperature {Delta}{sub 9cc}H{sub m}(T{sub fus}) was measured using differential scanning calorimetry. It was found that up to a mole fraction of the salt x = 0.931 in the (salt + zeolite) mixture, which is near the expected zeolite occlusion limit, {Delta}{sub occ}H{sub m}(T{sub fus}) was negative and directly proportional to x . Thus, within this composition range, the partial molar enthalpy of occlusion of the (lithium chloride + potassium chloride) eutectic salt in zeolite 4A at the salt melting temperature is constant and equal to - (24 {+-}1)kJ {center_dot} mol{sup -1}.

Lexa, D.; Chemical Engineering

1999-06-01

50

Catalytic gasification of coal using eutectic salt mixtures. Report for the Period April 1-September 30, 1998.  

National Technical Information Service (NTIS)

This progress report on the Department of Energy project DE-FG-97FT97263 entitled, 'Catalytic Gasification of Coal Using Eutectic Salt Mixtures' covers the period April-September 1998. The specific aims of the project for this period were to identify appr...

1998-01-01

51

Heat storage containers filled with the combination of a eutectic salt and a non-biodegradable filler material  

Microsoft Academic Search

A heat storage article adapted for prevention of stratification of heat storage materials, such as eutectic salts contained within the container element. The article is comprised of a heavy thermally conductive container with an internal cavity. The internal cavity of the container is substantially completely filled with a combination of a non-biodegradable filler material such as glass fiber insulation and

Schoenfelder

1980-01-01

52

On the reactive occlusion of the (uranium trichloride + lithium chloride + potassium chloride) eutectic salt in zeolite 4A  

Microsoft Academic Search

The interaction between the (uranium trichloride+lithium chloride+potassium chloride) eutectic salt and zeolite 4A has been studied by temperature-resolved synchrotron powder X-ray diffraction, evolved gas analysis and differential scanning calorimetry, between 300 and 900 K. The onset of salt occlusion by the zeolite has been detected at 450 K. Evidence of a reaction between zeolitic water and uranium trichloride, leading to

Dusan Lexa; Leonard Leibowitz; Jeremy Kropf

2000-01-01

53

UVvis absorption spectroscopic study for on-line monitoring of uranium concentration in LiClKCl eutectic salt  

Microsoft Academic Search

UVvis absorption spectroscopy of uranium in LiClKCl eutectic salt at 773K was studied for the on-site use in pyrochemical process. Uranium(III) chloride was electrochemically prepared from uranium metal in LiClKCl eutectic salt at 773K by using chronopotentiometry. Three absorption peak positions were selected and calibrated for the quantitative analysis of uranium in the molten salt medium. The molar absorptivity and

Y. J. Park; S. E. Bae; Y. H. Cho; J. Y. Kim; K. Song

2011-01-01

54

Catalytic gasification of coal using eutectic salts: reaction kinetics for hydrogasification using binary and ternary eutectic catalysts  

Microsoft Academic Search

A kinetic study of the hydrogasification of Illinois #6 coal was carried out using a ternary (43.5mol% Li2CO3-31.5mol% Na2CO3-25mol% K2CO3) and a binary (29mol% Na2CO3-71mol% K2CO3) eutectic system. Hydrogasification experiments were carried out in a high-pressure, high-temperature differential fixed-bed gasifier unit to evaluate the product inhibition effect of H2 on the overall steam gasification kinetics. The overall gasification rate was

Atul C Sheth; Chandramouli Sastry; Yaw D Yeboah; Yong Xu; Pradeep Agarwal

2004-01-01

55

Vacuum distillation of a mixture of LiClKCl eutectic salts and RE oxidative precipitates and a dechlorination and oxidation of RE oxychlorides  

Microsoft Academic Search

In this study, a vacuum distillation of a mixture of LiClKCl eutectic salt and rare-earth oxidative precipitates was performed to separate a pure LiClKCl eutectic salt from the mixture. Also, a dechlorination and oxidation of the rare-earth oxychlorides was carried out to stabilize a final waste form. The mixture was distilled under a range of 710759.5Torr of a reduced pressure

Hee Chul Eun; Hee Chul Yang; Yung Zun Cho; Han Soo Lee; In Tae Kim

2008-01-01

56

Temperature dependence of the f?f hypersensitive transitions of Ho3+ and Nd3+ in molten salt solvents and the structure of the LaCl3 KCl melts  

NASA Astrophysics Data System (ADS)

The electronic absorption spectra of the hypersensitive transitions 5G6?5I8 of Ho3+ and 4G5/2?4I9/2 of Nd3+ have been measured in molten LiCl KCl eutectic and in LaCl3 KCl molten mixtures. The ligand field components of the above transitions in octahedral symmetry have been identified and the molar absorptivity changes with temperature and composition have been measured. The spectra are discussed in terms of the coordination geometries of the probe cations Ho3+ and Nd3+ in these molten salt solvents. The Boltzmann thermal factor appears to be responsible in part for the variation of the hot band intensities. The data suggest that the predominant factors affecting the oscillator strength of the Ho3+ and Nd3+ hypersensitive transitions is the degree of octahedral distortions in conjunction with the overall charge asymmetry around the LnCl63- (Ln=Ho, Nd). It appears that no drastic changes occur in the coordination of the probe cations as we go from dilute in LaCl3 to pure LaCl3 melts; this suggests that in the host melt the coordination of La3+ is more likely to be six-fold. A further evidence for the six-fold coordination is given by the measured Judd Ofelt parameters of Nd3+ in both molten NdCl3 and La(Nd)Cl3.

Chrissanthopoulos, A.; Papatheodorou, G. N.

2006-01-01

57

X-Ray spectroscopy of frozen salt solutions: Are inclusions solid or liquid below the eutectic temperature?  

NASA Astrophysics Data System (ADS)

Natural ice in clouds and on the Earth surface contains many impurities, such as salts or acids. The chemical reactivity of these substances is defined by the thermodynamic state of the impurity. In ice, impurities may be in a solid or liquid. Moreover, impurities may be accumulated in confined reservoirs, such as grain boundaries or triple junctions. In these reservoirs premelting might occur. Hence salts may be in a liquid-like environment, even below the eutectic temperature. Using synchrotron based X-Ray absorption and fluorescence spectroscopy we study the physical state of salt ions in ice, which was frozen from dilute salt solutions. Using XANES and EXAFS we can determine whether the salt ions in the ice are in a solid or a liquid state.

Huthwelker, T.; Krepelova, A.; Zelenay, V.; Bartels-Rausch, T.; Janousch, M.; Ammann, M.

2009-04-01

58

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

NASA Astrophysics Data System (ADS)

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 50C, nearly 120C lower than the melting temperature of 3-2AP (172.5C). A cytotoxicity profile for 3-2AP exposed to A549 bronchoaveolar carcinoma cells revealed an LD50 of 337.65 mug/ml.

Sparrow, Christopher R.

59

Thermodynamic Assessment of Hot Corrosion Mechanisms of Superalloys Hastelloy N and Haynes 242 in Eutectic Mixture of Molten Salts KF and ZrF4.  

National Technical Information Service (NTIS)

This computational work models the behavior of Haynes 242 and Hastelloy N in the binary molten salt eutectic mixture KF-ZrF4. Limiting the principal alloying elements to fournickel, chromium, molybdenum, and ironallows reasonable conclusions to be made ab...

M. V. Glazoff

2012-01-01

60

Synthesis and electrochemical properties of lithium cobalt oxides prepared by molten-salt synthesis using the eutectic mixture of LiClLi 2CO 3  

Microsoft Academic Search

Lithium cobalt oxide powders have been successfully prepared by a molten-salt synthesis (MSS) method using a eutectic mixture of LiCl and Li2CO3 salts. The physico-chemical properties of the lithium cobalt oxide powders are investigated by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), particle-size analysis and chargedischarge cycling. A lower temperature and a shorter time (?700C and 1h) in the

Chi-Hwan Han; Young-Sik Hong; Chang Moon Park; Keon Kim

2001-01-01

61

Vacuum distillation of a mixture of LiCl-KCl eutectic salts and RE oxidative precipitates and a dechlorination and oxidation of RE oxychlorides.  

PubMed

In this study, a vacuum distillation of a mixture of LiCl-KCl eutectic salt and rare-earth oxidative precipitates was performed to separate a pure LiCl-KCl eutectic salt from the mixture. Also, a dechlorination and oxidation of the rare-earth oxychlorides was carried out to stabilize a final waste form. The mixture was distilled under a range of 710-759.5Torr of a reduced pressure at a fixed heating rate of 4 degrees C/min and the LiCl-KCl eutectic salt was completely separated from the mixture. The required time for the salt distillation and the starting temperature for the salt vaporization were lowered with a reduction in the pressure. Dechlorination and oxidation of the rare-earth oxychlorides was completed at a temperature below 1300 degrees C and this was dependent on the partial pressure of O2. The rare-earth oxychlorides (NdOCl/PrOCl) were transformed to oxides (Nd2O3/PrO2) during the dechlorination and oxidation process. These results will be utilized to design a concept for a process for recycling the waste salt from an electrorefining process. PMID:18440139

Eun, Hee Chul; Yang, Hee Chul; Cho, Yung Zun; Lee, Han Soo; Kim, In Tae

2008-03-22

62

Tungsten fluorides: syntheses and electrochemical characterization in the FLINAK molten salt eutectic.  

PubMed

The following tungsten fluorides have been synthesized by simple addition reactions or by reduction with tungsten metal at elevated temperature: KWF7, K2WF8, MWF6 (M = K, Na, Rb, Cs), K2WF7, M3WF8 (M = K, Na, Rb), and K3WF6. The compounds were characterized by their Raman spectra and by cyclic voltammetry in the molten FLINAK eutectic melt (46.5, 11.5, and 42.0 mol % of LiF, NaF, and KF, respectively) at 475-800 degrees C. X-ray crystal structures are reported for two new compounds K2WF7 and K3WF6. The crystals of K2WF7 were orthorhombic, space group Pnma (No. 62) with a = 9.800(2) A, b = 5.7360(11) A, c = 11.723(2) A, and Z = 4. Crystals of K3WF6 were cubic, space group Fm3 (No. 225) with a = b = c = 8.9160(10) A, Z = 4. Electrodeposition of tungsten metal on Pt from FLINAK, prepared by the addition of WF6 gas and metallic tungsten to the melt, is suggested to result from reduction of an equilibrium mixture of WF8(3-) and WF6(3-). PMID:11225114

Eklund, S E; Chambers, J Q; Mamantov, G; Diminnie, J; Barnes, C E

2001-02-12

63

Low temperature molten salt synthesis of SrTiO 3 submicron crystallites and nanocrystals in the eutectic NaClKCl  

Microsoft Academic Search

An eutectic NaClKCl molten salts method has been developed for the synthesis of SrTiO3 submicron crystallites and nanocrystals from SrO2 and two kinds (submicron and nano-sized) of TiO2 powders at 700C, which was much lower than that (generally>1000C) of the conventional solid state reactions. The characterization results from X-ray diffraction and X-ray photoelectron spectroscopy revealed that the obtained products were

Hui-Ling Li; Zhen-Ni Du; Gen-Lin Wang; Yong-Cai Zhang

2010-01-01

64

Electrochemical Study on the Electrodeposition of U, Nd, Ce, La and Y on a Liquid Cadmium Cathode in a LiCl-KCl Eutectic Salt  

Microsoft Academic Search

Electro-depositions of U, Nd, Ce, La and Y on a liquid cadmium cathode in a LiCl-KCl eutectic salt were studied by using an electrolytic cell. For the LiCl-KCl-UCl- NdCl-CeCl-LaCl-YCl\\/Cd system, cyclic voltammograms and polarization curves were measured and the electrochemical properties of the system were discussed. From the results of the electro-depositions of U and rare earth metals on the

Sung Bin Park; Jong Hyeon Lee; Sung Chan Hwang; Young Ho Kang; Joon Bo Shim; Han Soo Lee; Eung Ho Kim; Seong Won Park

2007-01-01

65

Eutectics and Phase Diagrams of Molten Salts from Molecular Dynamics simulations  

Microsoft Academic Search

The use of alkali nitrate salt mixtures as heat transfer fluids in solar thermal power plants is limited by their relatively high melting point. Certain compositions of quaternary and higher dimensional mixtures of alkali and alkaline earth nitrates and nitrites have low melting points. However, the high dimensionality of the search space makes it difficult to find lowest melting compositions.

Saivenkataraman Jayaraman; Anatole von Lilienfeld; Aidan Thompson

2011-01-01

66

Synthesis and properties of high tap-density cathode material for lithium ion battery by the eutectic molten-salt method  

Microsoft Academic Search

Spherical Li(Ni1\\/3Co1\\/3Mn1\\/3)O2 with a layered structure has been successfully prepared by the eutectic molten-salt method using 0.24LiCO30.76LiOH (with a melting point of 423C) and (Ni1\\/3Co1\\/3Mn1\\/3)(OH)2, where the ratio of Li\\/(Ni+Co+Mn) is controlled at 1:1. The tap-density of the powders obtained in this work (2.89) is remarkably higher than that of spherical Li(Ni1\\/3Co1\\/3Mn1\\/3)O2 powders synthesized by other single lithium salts (2.40).

Zhaorong Chang; Zhongjun Chen; Feng Wu; Hongwei Tang; Zhihong Zhu; Xiao Zi Yuan; Haijiang Wang

2008-01-01

67

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

Microsoft Academic Search

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

Tom B. Bechtel; Truman S. Storvick

1999-01-01

68

Calibration of gas pressure using the mercury melting curve in conjunction with eutectic ice-salt mixtures  

Microsoft Academic Search

Eutectic freezing mixtures of ice-KNO3, ice-KCl, ice-NH4Cl and ice-NaCl provide a convenient method of obtaining uniform temperatures close to -2.8, -10.6, -15.3 and -21.1 degrees C, respectively. Calibration to better than +or-0.1% is achievable for gas pressures between 344 and 701 MPa when these mixtures are used in conjunction with a mercury pressure cell and a resistance thermometer accurate to

J. Lusk

1990-01-01

69

Temperature dependence of the elastic moduli and damping for polycrystalline LiF22% CaF 2 eutectic salt  

Microsoft Academic Search

The Young's and shear moduli and damping were measured for as-cast polycrystalline LiF-22 (mol%) CaF2 eutectic specimens as a function of temperature using the piezoelectric ultrasonic composite oscillator technique (PUCOT). The shear modulus decreased with increasing temperature from about 40 GPa at 295 K to about 30 GPa at 1000 K, while the Young's modulus decreased from about 115 GPa

A. Wolfenden; G. Lastrapes; M. B. Duggan; S. V. Raj

1991-01-01

70

Separation of actinides from rare earth elements by means of molten salt electrorefining with anodic dissolution of U Pu Zr alloy fuel  

NASA Astrophysics Data System (ADS)

Electrorefining is the main process for pyro-reprocessing of the fuel of a metallic fuel FBR. To obtain a basic knowledge of electrorefining technology, a series of experiments was carried out with unirradiated fuel alloy. The alloy, 71U 19Pu 10Zr (wt.%), was dissolved anodically into a molten LiCl KCl bath at 753 K. Simultaneously, Pu and U were recovered into the Cd cathode with small amounts of minor actinides, Zr and rare earth elements (REs). The separation factors of U, Np, Am, Cm and Ce against Pu, derived from the composition of recovered deposits and of the salt bath, were about 2.04, 0.949, 0.597, 0.534 and 0.0393, respectively, which are similar to the equilibrium values observed in a distribution experiment in a LiCl KCl/Cd system. This demonstrates that electrorefining achieves the separation of actinides from REs. The anodic dissolution of the alloy was found to progress from the outside, leaving a dense layer containing salt and Zr metal around the alloy surface. It was found that more than 99.9% of both U and Pu could be dissolved from the alloy and about 55% of Zr remained in this layer.

Kinoshita, Kensuke; Koyama, Tadafumi; Inoue, Tadashi; Ougier, Michel; Glatz, Jean-Paul

2005-02-01

71

Electrochemical Study on the Electrodeposition of U, Nd, Ce, La and Y on a Liquid Cadmium Cathode in a LiCl-KCl Eutectic Salt  

SciTech Connect

Electro-depositions of U, Nd, Ce, La and Y on a liquid cadmium cathode in a LiCl-KCl eutectic salt were studied by using an electrolytic cell. For the LiCl-KCl-UCl{sub 3}- NdCl{sub 3}-CeCl{sub 3}-LaCl{sub 3}-YCl{sub 3}/Cd system, cyclic voltammograms and polarization curves were measured and the electrochemical properties of the system were discussed. From the results of the electro-depositions of U and rare earth metals on the LCC, separation factors and recovery ratios of U and REs were obtained and co-electro-depositions of U and REs were investigated. (authors)

Sung Bin Park; Jong Hyeon Lee; Sung Chan Hwang; Young Ho Kang; Joon Bo Shim; Han Soo Lee; Eung Ho Kim; Seong Won Park [Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon, 305-353 (Korea, Republic of)

2007-07-01

72

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

SciTech Connect

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.

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

1999-04-01

73

Scaling-Up Eutectic Freeze Crystallization  

Microsoft Academic Search

A novel crystallization technology, Eutectic Freeze Crystallization (EFC) has been investigated and further developed in this thesis work. EFC operates around the eutectic temperature and composition of aqueous solutions and can be used for recovery of (valuable) dissolved salts (and\\/or or acids) and water from a wide variety of aqueous process streams. Using EFC, processes producing large quantities of saline

F. E. Genceli

2008-01-01

74

Optical properties of a solar-absorbing molten salt heat transfer fluid. [Eutectic mixture of KNO3, NaNO2, and NaNO3 with particle suspensions of cobalt oxides or copper oxides  

Microsoft Academic Search

The optical absorption properties of a high temperature molten salt heat transfer fluid were measured from 0.35 ..mu..m to 2.5 ..mu..m using both hemispherical transmission and reflection techniques. This fluid has application as a direct-absorbing working fluid in a high temperature central receiver solar energy facility. The absorption spectrum of the pure molten fluid--a eutectic mixture of KNO, NaNO, and

Drotning

1977-01-01

75

Study on the oxidizing reaction of rare-earth chlorides (CeCl 3 and PrCl 3 ) in LiCl-KCI eutectic salt by O 2 injection  

Microsoft Academic Search

The oxidizing reaction of some rare-earth chlorides (Pr\\/CeCl3) in an eutectic (LiCl-KCl) salt was studied by O2 injection. In this study, oxychlorides (REOCl) or oxides (REO2) were formed as reaction products. The results conformed to the thermodynamic equilibrium data calculated by HSC-Chemistry\\u000a 5.1 software. The conversion ratio of the rare-earth chlorides to insoluble precipitates was over 0.999, after injecting O2

H. C. Eun; Y. J. Cho; H. C. Yang; H. S. Park; E. H. Kim; I. T. Kim

2007-01-01

76

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

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

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

1995-01-01

77

Interaction Between Aluminum Nitride-Based Composite Materials and a CaCl2 KCl Eutectic Molten Salt Solution  

Microsoft Academic Search

The interaction between composite materials based on aluminum nitride and a phosphate binder (PB) and a CaCl2 KCl molten salt solution is studied as a function of time (10 220 h) by a gravimetric method. The test specimens studied were sintered (AlN + PB)-based composite, hot-pressed Y2O3-doped aluminum nitride, graphite, and (AlN + PB)-coated graphite. The concentration of

L. B. Khoroshavin; A. R. Beketov; D. A. Beketov; Yu. P. Zaikov; V. V. Chebykin

2002-01-01

78

The synthesis of Li(Ni 1\\/3Co 1\\/3Mn 1\\/3)O 2 using eutectic mixed lithium salt LiNO 3LiOH  

Microsoft Academic Search

A lithium-ion battery cathode material, Li(Ni1\\/3Co1\\/3Mn1\\/3)O2, with excellent electrochemical properties was prepared via two-step isothermal sintering, using eutectic lithium salts (0.38LiOHH2O0.62LiNO3) mixed with Co, Ni, or Mn hydroxides. Based on analysis using X-ray diffraction (XRD), scanning electron microscopy (SEM), a thermogravimetric-differential scanning calorimetric (TGDSC) analyzer, and Fourier-transform Infrared (FT-IR), this synthetic process consists of procedures including lithium salt melting, permeation,

Zhaorong Chang; Zhongjun Chen; Feng Wu; Xiao-Zi Yuan; Haijiang Wang

2009-01-01

79

Synthesis of LiNi 1\\/3Co 1\\/3Al 1\\/3O 2 cathode material with eutectic molten salt LiOH-LiNO 3  

Microsoft Academic Search

A lithium-ion battery cathode material, LiNi1\\/3Co1\\/3Al1\\/3O2, with excellent electrochemical properties was prepared by three-phase temperature sintering, using eutectic lithium salts (0.38LiOH.H2O-0.62LiNO3) mixed with the precursor Ni1\\/3Co1\\/3Al1\\/3(OH)2. This method was simple and inexpensive, and the materials could be mixed uniformly at the eutectic melting point without any grinding. A well-layered ?-NaFeO2 structure was confirmed by X-ray diffraction (XRD). The ratio of

Zhao-Rong Chang; Xu Yu; Hong-Wei Tang; Xiao-Zi Yuan; Haijiang Wang

2011-01-01

80

EUTECTIC DATA: safety, hazards, corrosion, melting points, compositions, and bibliography  

Microsoft Academic Search

The present compilation provides an authoritative compendium of properties relative to safety, hazards, corrosion, melting points, and compositions of molten salt eutectic mixtures. The scope of the single salts data in this compilation encompasses the end-components of the eutectic mixtures reported. Each section contains a systems index and bibliography. The bibliographies in Pt. 1 and Pt. 2 total approximately 4000

G. J. Janz; C. B. Allen; J. R. Jr. Downey; R. P. T. Tomkins

1976-01-01

81

EUTECTIC DATA: safety, hazards, corrosion, melting points, compositions, and bibliography  

Microsoft Academic Search

The compilation provides an authoritative compendium of properties relative to safety, hazards, corrosion, melting points, and compositions of molten salt eutectic mixtures. The scope of the single salts data in this compilation encompasses the end-components of the eutectic mixtures reported herewith. Each section contains a systems index and bibliography. The bibliographies in Pt. 1 and Pt. 2 total approximately 4000

G. J. Janz; C. B. Allen; J. R. Jr. Downey; R. P. T. Tomkins

1976-01-01

82

Electrochemical impedance investigations of redox mechanisms of refractory metal compounds in molten salts. I. Niobium chloride and oxychloride in CsClNaCl eutectic melt  

Microsoft Academic Search

Electrochemical studies of the redox mechanisms of niobium chloride and oxychloride in CsClNaCl eutectic melts at 550C are reported. Cyclic voltammograms and electrochemical impedance spectra have been measured in situ over a wide potential range between the limits of chlorine evolution and metal deposition at various oxide concentrations 0?Ox\\/Nb?3. In analyzing the impedance spectra we have focused on the determination

U. Sthr; W. Freyland

1999-01-01

83

Measurement of standard potentials of actinides (U,Np,Pu,Am) in LiClKCl eutectic salt and separation of actinides from rare earths by electrorefining  

Microsoft Academic Search

Pyrochemical separation of actinides from rare earths in LiClKCl eutecticliquid metal systems has been studied. The electromotive forces of galvanic cells of the form, Ag|Ag(I), LiClKCl?actinide(III), LiClKCl|actinide, were measured and standard potentials were determined for uranium, neptunium and plutonium to be ?1.283 V, ?1.484 V and ?1.593 V (at 450C vs. Ag\\/AgCl (1wt%AgCl)), respectively. A typical cyclic voltammogram of americium

Y. Sakamura; T. Hijikata; K. Kinoshita; T. Inoue; T. S. Storvick; C. L. Krueger; J. J. Roy; D. L. Grimmett; S. P. Fusselman; R. L. Gay

1998-01-01

84

Testing of pyrochemical centrifugal contactors  

SciTech Connect

A centrifugal contactor that performs oxidation and reduction exchange reactions between molten metals and salts at 500 degrees Centigrade has been tested successfully at Argonne National Laboratory (ANL). The design is based on contactors for aqueous- organic systems operation near room temperature. In tests to demonstrate the performance of the pyrocontactor, cadmium and LICl- KCl eutectic salt were the immiscible solvent phases, and rare earths were the distributing solutes. The tests showed that the pyrocontactor mixed and separated the phases well, with stage efficiencies approaching 99% at rotor speeds near 2700 rpm. The contactor ran smoothly and reliably over the entire range of speeds that was tested.

Chow, L.S.; Carls, E.L.; Basco, J.K.; Johnson, T.R.

1996-08-01

85

Eutectic composite explosives containing ammonium nitrate  

SciTech Connect

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.

Stinecipher, M.M.

1981-01-01

86

Fast dissolving eutectic compositions of curcumin.  

PubMed

The bioactive herbal ingredient curcumin was screened with pharmaceutically acceptable coformers to discover solid-state forms of high solubility. Mechano-chemical grinding of curcumin with cocrystal formers in a fixed stoichiometry ratio resulted in binary eutectic compositions of curcumin-coformer with nicotinamide (1:2), ferulic acid (1:1), hydroquinone (1:1), p-hydroxybenzoic acid (1:1), and l-tartaric acid (1:1). The eutectic nature of the product crystalline solids was established by differential scanning calorimetry, and the absence of hydrogen-bonded crystalline phases such as cocrystals/salts was ascertained by powder X-ray diffraction, IR-Raman, and solid-state NMR spectroscopy. The best case of CUR-NAM eutectic exhibits 10-fold faster IDR and 6-times higher AUC compared to crystalline curcumin. PMID:23041131

Goud, N Rajesh; Suresh, Kuthuru; Sanphui, Palash; Nangia, Ashwini

2012-10-03

87

Effect of salts on the water sorption kinetics of dried pasta.  

PubMed

The water sorption kinetics of dried pasta were measured in the 20-90 C range in 1.83 mol/L of NaCl and at 80 C in 1.83 mol/L of LiCl, KCl, NaBr and NaI solutions in order to elucidate the role of salt in the kinetics. At the temperatures higher than 70.8 C, the change in the enthalpy of sorption, ?H, in the 1.83 mol/L NaCl solution was 33.1 kJ/mol, which was greater than the ?H value in water, and the activation energy for the sorption, E, in the salt solution was 25.6 kJ/mol, which was slightly lower than the E value in water. The Hofmeister series of ions was an index for their effect on the equilibrium amount of the sorbed solution of pasta. The apparent diffusion coefficient of water into pasta was not correlated with the crystal radius of the salts, but was with the Stokes radius of the hydrated ions. Equations were formulated to predict the amount of sorbed solution under any condition of temperature and NaCl concentration. PMID:23391911

Ogawa, Takenobu; Adachi, Shuji

2013-02-07

88

Thermodynamic Assessment of Hot Corrosion Mechanisms of Superalloys Hastelloy N and Haynes 242 in Eutectic Mixture of Molten Salts KF and ZrF4  

SciTech Connect

The KF - ZrF4 system was considered for the application as a heat exchange agent in molten salt nuclear reactors (MSRs) beginning with the work carried out at ORNL in early fifties. Based on a combination of excellent properties such as thermal conductivity, viscosity in the molten state, and other thermo-physical and rheological properties, it was selected as one of possible candidates for the nuclear reactor secondary heat exchanger loop.

Michael V. Glazoff

2012-02-01

89

Density measurements of the lithium fluoride\\/lithium sulfide eutectic at high temperature  

Microsoft Academic Search

A straightforward and reliable method to determine densities of molten salts at high temperatures was de-veloped by Janz and Lorenz several years ago.[1] This method was followed in order to determine the density of the LiF\\/Li2S eutectic[2] over the temperature range of 1176 to 1355 K in which the eutectic is liquid. The rel-ative lack of data for this eutectic

Charles L. Lloyd; James B. Gilbert

1994-01-01

90

Density measurements of the lithium fluoride\\/lithium sulfide eutectic at high temperature  

Microsoft Academic Search

A straightforward and reliable method to determine densities of molten salts at high temperatures was de-veloped by Janz and\\u000a Lorenz several years ago.[1] This method was followed in order to determine the density of the LiF\\/Li2S eutectic[2] over the temperature range of 1176 to 1355 K in which the eutectic is liquid. The rel-ative lack of data for this eutectic

Charles L. Lloyd; James B. Gilbert

1994-01-01

91

Solubility products of metal sulfides in molten salts: II. Measurements and calculations for lead sulfide in the LiCl-KCl and the LiCl-LiF eutectic compositions  

Microsoft Academic Search

The solubilities of lithium sulfide and the solubility products of lead sulfide in the LiCl-KCI and LiCI-LiF eutectic mixtures\\u000a have been measured by an electrochemical titration method in the temperature range from 673 to 823 K. At 823 K, the solubility\\u000a of Li2S in the LiCI-LiF eutectic was much larger than in the LiCI-KCI eutectic (1.95 ? 10?1 compared with

M. L. Saboungi; J. J. Marr; M. Blander

1979-01-01

92

New eutectic alloys and their heats of transformation  

NASA Astrophysics Data System (ADS)

Eutectic compositions and congruently melting intermetallic compounds in binary and multi-component systems among common elements such as AI, Ca, Cu, Mg, P, Si, and Zn may be useful for high temperature heat storage. In this work, heats of fusion of new multicomponent eutectics and intermetallic phases are reported, some of which are competitive with molten salts in heat storage density at high temperatures. The method used to determine unknown eutectic compositions combined results of differential thermal analysis, metallography, and microprobe analysis. The method allows determination of eutectic compositions in no more than three steps. The heats of fusion of the alloys were measured using commercial calorimeters, a differential thermal analyzer, and a differential scanning calorimeter.

Farkas, Diana; Birchenall, C. E.

1985-03-01

93

Re-evaluation of the eutectic region of the LiBr-KBr-LiF system.  

National Technical Information Service (NTIS)

The development of a two-hour thermal battery required the use of a molten salt that had a lower melting point and larger liquidus range than the LiCl-KCl eutectic which melts at 352 C. Several candidate eutectic electrolyte systems were evaluated for the...

L. Redey R. A. Guidotti

1996-01-01

94

Coatings for Directional Eutectics.  

National Technical Information Service (NTIS)

Significant advances have been made in the development of an environmentally stable coating for a very high strength, directionally solidified eutectic alloy designated NiTaC-13. Three duplex (two-layer) coatings survived 3,000 hours on a cyclic oxidation...

J. R. Rairden M. R. Jackson

1976-01-01

95

Supramolecular ensembles in eutectic alloys  

NASA Astrophysics Data System (ADS)

The main concepts of the theory of eutectics are analysed. The most essential results of investigations on eutectic alloys of inorganic compounds are surveyed. Evidence in favour of the supramolecular concept of eutectics is presented. This concept takes into account interactions of incommensurate substructures and gives an insight into the mechanisms of formation of supramolecular eutectic assemblies in boundary regions ('non-autonomous phases'). Using the static one-dimensional Frenkel Kontorova model for finite systems, it is shown that the consideration of these mechanisms in terms of supramolecular chemistry simplifies analysis of the behaviour of inorganic eutectic systems in the course of crystallisation under conditions both close to and far from equilibrium, including crystallization upon quenching and under external actions. The supramolecular concept bridges gaps between the definitions 'compound', 'eutectic' and 'solution' in physicochemical analysis.

Pervov, Vladislav S.; Mikheikin, Igor'D.; Makhonina, Elena V.; Butskii, Vladimir D.

2003-09-01

96

Detectability by Radar of Salts in Martian Ice Deposits  

NASA Astrophysics Data System (ADS)

Salt in martian ice could have significant implications for ice-rheology near and above eutectic temperatures. Using laboratory data and dielectric modeling, we investigate detection of salts, including perchlorate salts, using radar attenuation.

Winebrenner, D. P.; Stillman, D. E.; Grimm, R. E.

2011-03-01

97

Chalcogenide chemistry in molten salts. I. Selenium(IV) acido-basic and redox properties in the LiClKCl eutectic melt at 450, 500, 550 and 600 C  

Microsoft Academic Search

Molten salt chemistry of chalcogenides has become a major concern in relation to two current great application domains which are (i) nuclear energy (pyrochemical nuclear waste treatment and molten salt reactors) and (ii) electrodeposition of functional material thin films (photovoltaic, magnetism, supraconductivity, etc.). This paper reports experimental data relevant to the molten salt chemistry of selenium in the molten LiClKCl

Sylvie Rouquette-Sanchez; Grard S. Picard

2004-01-01

98

Distribution behavior of plutonium and americium in LiClKCl eutectic\\/liquid cadmium systems  

Microsoft Academic Search

The thermodynamics of plutonium and americium in LiClKCl 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 LiClKCl eutectic was measured in the temperature range of 400500C and given by the equation with a standard deviation, ?=0.0009

Y Sakamura; O Shirai; T Iwai; Y Suzuki

2001-01-01

99

Electrochemical method of producing eutectic uranium alloy and apparatus  

DOEpatents

An apparatus and method for continuous production of liquid uranium alloys through the electrolytic reduction of uranium chlorides. The apparatus includes an electrochemical cell formed from an anode shaped to form an electrolyte reservoir, a cathode comprising a metal, such as iron, capable of forming a eutectic uranium alloy having a melting point less than the melting point of pure uranium, and molten electrolyte in the reservoir comprising a chlorine or fluorine containing salt and uranium chloride. The method of the invention produces an eutectic uranium alloy by creating an electrolyte reservoir defined by a container comprising an anode, placing an electrolyte in the reservoir, the electrolyte comprising a chlorine or fluorine containing salt and uranium chloride in molten form, positioning a cathode in the reservoir where the cathode comprises a metal capable of forming an uranium alloy having a melting point less than the melting point of pure uranium, and applying a current between the cathode and the anode.

Horton, James A. (Livermore, CA); Hayden, H. Wayne (Oakridge, TN)

1995-01-01

100

Ethylenediamine Salt of 5-Nitrotetrazole and Preparation.  

National Technical Information Service (NTIS)

The ethylenediamine salt of 5-nitrotetrazole has been found to be useful as an explosive alone and in eutectic mixtures with ammonium nitrate and/or other explosive compounds. Its eutectic with ammonium nitrate has been demonstrated to behave in a similar...

K. Lee M. D. Coburn

1984-01-01

101

CONTRIBUTION TO A STUDY ON THE OBTENTION OF HIGH PURITY BERYLLIUM BY ELECTROREFINING FROM FUSED SALT BATHS  

Microsoft Academic Search

By electrolytic refining at 400 to 500 deg C from molten baths ; containing a LiCl-- KCl--BeCl mixture, beryllium of high purity can be ; obtained. A study of this method of purification established the following ; characteristic features: 1) One can use the necessary anhydrous baths by ; dissolving lten LiClKCl solvent itself by the chemical displacement reaction Be

G. Boisde; M. Broc; G. Chauvin; H. Coriou; J. Hure; P. Jarny

1962-01-01

102

Ethylenediamine salt of 5-nitrotetrazole and preparation  

SciTech Connect

Ethylenediamine salt of 5-nitrotetrazole and preparation are disclosed. This salt has been found to be useful as an explosive alone and in eutectic mixtures with ammonium nitrate and/or other explosive compounds. Its eutectic with ammonium nitrate has been demonstrated to behave in a similar manner to a monomolecular explosive such as TNT, and is less sensitive than the pure salt. Moreover, this eutectic mixture, which contains 87.8 mol % of ammonium nitrate, is close to the CO/sub 2/-balanced composition of 90 mol %, and has a relatively low melting point of 110.5 C making it readily castable. The ternary eutectic system containing the ethylenediamine salt of 5-nitrotetrazole, ammonium nitrate and ethylenediamine dinitrate has a eutectic temperature of 89.5 C and gives a measured detonation pressure of 24.8 GPa, which is 97.6% of the calculated value. Both the pure ethylenediamine salt and its known eutectic compounds behave in substantially ideal manner. Methods for the preparation of the salt are described.

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

1985-11-12

103

Ethylenediamine salt of 5-nitrotetrazole and preparation  

DOEpatents

Ethylenediamine salt of 5-nitrotetrazole and preparation. This salt has been found to be useful as an explosive alone and in eutectic mixtures with ammonium nitrate and/or other explosive compounds. Its eutectic with ammonium nitrate has been demonstrated to behave in a similar manner to a monomolecular explosive such as TNT, and is less sensitive than the pure salt. Moreover, this eutectic mixture, which contains 87.8 mol % of ammonium nitrate, is close to the CO.sub.2 -balanced composition of 90 mol %, and has a relatively low melting point of 110.5 C. making it readily castable. The ternary eutectic system containing the ethylenediamine salt of 5-nitrotetrazole, ammonium nitrate and ethylenediamine dinitrate has a eutectic temperature of 89.5 C. and gives a measured detonation pressure of 24.8 GPa, which is 97.6% of the calculated value. Both the pure ethylenediamine salt and its known eutectic compounds behave in substantially ideal manner. Methods for the preparation of the salt are described.

Lee, Kien-yin (Los Alamos, NM); Coburn, Michael D. (Los Alamos, NM)

1985-01-01

104

Investigation of nitrate salts for solar latent heat storage  

Microsoft Academic Search

The properties of heat transfer in the discharging of a model solar latent heat storage unit based on various nitrate salts and salt mixtures are investigated. A shell-and-tube-type passive heat exchanger containing NaNO3 or eutectic or off-eutectic mixtures of NaNO3 with KNO3 and Ca(NO3)2 was heated to 40 K above the melting temperature of the salt, when air was made

M. Kamimoto; T. Tanaka; T. Tani; T. Horigome

1980-01-01

105

Prevention of crystallization fouling during eutectic freeze crystallization in fluidized bed heat exchangers  

Microsoft Academic Search

Eutectic freeze crystallization is a promising separation technique to produce salt and ice crystals with very high purities and requires less energy than competitive evaporative crystallization techniques. A drawback of this technique is crystallization fouling, which seriously reduces heat transfer rates. Solidliquid fluidized bed heat exchangers may be attractive crystallizers for this purpose, since they have demonstrated to prevent severe

P. Pronk; C. A. Infante Ferreira; G. J. Witkamp

2008-01-01

106

Design of a Eutectic Freeze Crystallization process for multicomponent waste water stream  

Microsoft Academic Search

Complex, hypersaline brines originating from the mining and extractive metallurgical industries have the potential to be treated using Eutectic Freeze Crystallization (EFC). Although EFC has been shown to be effective in separating a single salt and water, it has yet to be applied to the complex hypersaline brines that are typical of reverse osmosis retentates in South Africa. This paper

A. E. Lewis; J. Nathoo; K. Thomsen; H. J. Kramer; G. J. Witkamp; S. T. Reddy; D. G. Randall

2010-01-01

107

Corrosion of Selected Alloys in Eutectic Lithium-Sodium-Potassium Carbonate at 900 deg C.  

National Technical Information Service (NTIS)

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 ...

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

1986-01-01

108

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

Microsoft Academic Search

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

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

1986-01-01

109

Eutectic solidification and its role in casting porosity formation  

NASA Astrophysics Data System (ADS)

Understanding and controlling the eutectic solidification process in Al-Si alloys permits prediction of the formation of casting porosity, eventually leading to methods for its control and elimination. In addition, it enables control of eutectic structure, silicon morphology, and eutectic grain size to further improve the alloy properties. This paper presents the current understanding of eutectic solidification in hypoeutectic Al-Si foundry alloys and the relationship between eutectic solidification and porosity formation. New concepts in engineering eutectic solidification are also explored.

Lu, L.; Nogita, K.; McDonald, S. D.; Dahle, A. K.; Lu, L.; Dahle, A. K.

2004-11-01

110

Low Temperature Synthesis of Lithium Manganese Oxide Using LiCl-Li2CO3 and Manganese Acetate Eutectic Mixture  

Microsoft Academic Search

Fine crystalline LiMn2O4 powders have been prepared by Molten-Salt Synthesis (MSS) at 500C, using an eutectic mixture of lithium chloride, lithium carbonate and manganese acetate salts. Thermo Gravimetric and Differential Thermal Analysis (TGA\\/DTA) measurements are performed to investigate the thermal decomposition behavior of the precursor salts. The single-phase cubic structure of LiMn2O4 is confirmed by X-ray powder diffraction analysis. The

M. Helan; L. John Berchmans

2011-01-01

111

Eutectic nucleation in Al-Si alloys  

SciTech Connect

In addition to a change in silicon morphology, modification of aluminium-silicon alloys with strontium or sodium increases the size of the eutectic grains. To determine the mechanism responsible, eutectic solidification in commercial purity and ultra-high purity aluminium-silicon alloys, with and without strontium additions, was examined by a quenching technique. In the commercial unmodified alloy, nucleation was prolific while in the high-purity unmodified alloy few eutectic grains nucleated. The addition of strontium to the commercial alloy reduced the number of eutectic grains that nucleated. Addition of strontium to the high-purity alloy did not significantly alter nucleation. It is concluded that commercial purity alloys contain a large number of potent nuclei that are susceptible to poisoning by impurity modification. The flake-to-fibre transition that occurs with impurity modification is shown to be independent of any change in eutectic nucleation mode and frequency.

McDonald, Stuart D.; Nogita, Kazuhiro; Dahle, Arne K

2004-08-16

112

Eutectic melting in metal borohydrides.  

PubMed

A series of monometallic borohydrides and borohydride eutectic mixtures have been investigated during thermal ramping by mass spectroscopy, differential scanning calorimetry, and photography. Mixtures of LiBH4-NaBH4, LiBH4-KBH4, LiBH4-Mg(BH4)2, LiBH4-Ca(BH4)2, LiBH4-Mn(BH4)2, NaBH4-KBH4, and LiBH4-NaBH4-KBH4 all displayed melting behaviour below that of the monometallic phases (up to 167 C lower). Generally, each system behaves differently with respect to their physical behaviour upon melting. The molten phases can exhibit colour changes, bubbling and in some cases frothing, or even liquid-solid phase transitions during hydrogen release. Remarkably, the eutectic melt can also allow for hydrogen release at temperatures lower than that of the individual components. Some systems display decomposition of the borohydride in the solid-state before melting and certain hydrogen release events have also been linked to the adverse reaction of samples with impurities, usually within the starting reagents, and these may also be coupled with bubbling or frothing of the ionic melt. PMID:24141723

Paskevicius, Mark; Ley, Morten B; Sheppard, Drew A; Jensen, Torben R; Buckley, Craig E

2013-10-21

113

Electrochemical method of producing eutectic uranium alloy and apparatus  

DOEpatents

An apparatus and method are disclosed for continuous production of liquid uranium alloys through the electrolytic reduction of uranium chlorides. The apparatus includes an electrochemical cell formed from an anode shaped to form an electrolyte reservoir, a cathode comprising a metal, such as iron, capable of forming a eutectic uranium alloy having a melting point less than the melting point of pure uranium, and molten electrolyte in the reservoir comprising a chlorine or fluorine containing salt and uranium chloride. The method of the invention produces an eutectic uranium alloy by creating an electrolyte reservoir defined by a container comprising an anode, placing an electrolyte in the reservoir, the electrolyte comprising a chlorine or fluorine containing salt and uranium chloride in molten form, positioning a cathode in the reservoir where the cathode comprises a metal capable of forming an uranium alloy having a melting point less than the melting point of pure uranium, and applying a current between the cathode and the anode. 2 figures.

Horton, J.A.; Hayden, H.W.

1995-01-10

114

Applications of Molten Salts in Plutonium Processing.  

National Technical Information Service (NTIS)

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 deg C. These processes usually employ a molten salt or salt eutectic as a heat sink and/or reac...

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

1987-01-01

115

Molten salt pyrolysis of latex  

Microsoft Academic Search

Latex-rich plants such as guayule or extracts thereof pyrolyzed in an inert nitrogen atmosphere in inorganic salt melts such as a LiCl\\/KCl eutectic at a temperature of about 500°C. Yield over 60% of a highly aromatic, combustible hydrocarbon oil suitab for use as a synthetic liquid fuel.

Bauman

1981-01-01

116

Re-evaluation of the eutectic region of the LiBr-KBr-LiF system  

SciTech Connect

The separator pellet in a thermal battery consists of electrolyte immobilized by a binder (typically, MgO powder). The melting point of the electrolyte determines the effective operating window for its use in a thermal battery. The development of a two-hour thermal battery required the use of a molten salt that had a lower melting point and larger liquidus range than the LiCl-KCl eutectic which melts at 352 C. Several candidate eutectic electrolyte systems were evaluated for their suitability for this application. One was the LiCl-LiBr-KBr eutectic used at Argonne National Laboratories for high-temperature rechargeable batteries for electric-vehicle applications. Using a custom-designed high-temperature conductivity cell, the authors were able to readily determine the liquidus region for the various compositions studied around the original eutectic for the LiBr-KBr-LiF system. The actual eutectic composition was found to be 60.0 m/o LiBr-37.5 m/o KBr-2.5 m/o LiF with a melting point of 324 {+-} 0.5 C.

Redey, L. [Argonne National Lab., IL (United States); Guidotti, R.A. [Sandia National Labs., Albuquerque, NM (United States)

1996-05-01

117

Power plant I - Fused salt  

NASA Astrophysics Data System (ADS)

A solar thermal power plant using fused salt as the heat transfer fluid for steam power generation is analyzed for the feasibility of economic operation. The salt is also stored in a tank reservoir for maintaining the primary heat loop at temperatures high enough for the salts to remain liquid, and also to provide reserve power for the steam generator. Initial studies were with eutectic (hitec) salt comprising Na, KOH, and nitrites melting at 146 C, and further studies were performed employing draw salt, which has no nitrite, is more stable at high temperature, and melts at 225 C. The use of draw salt was found to allow a 5 percent reduction in storage capacity. Further examinations of the effects of the hitec salts on corrosion and composition degradation at high temperatures are indicated. The molten salt system is projected to offer an efficiency of 26 percent.

Roche, M.

118

Synthesis and Characterization of New Materials in Molten Salt Fluxes  

Microsoft Academic Search

The main goal of this research was to explore molten salts as growth media for the synthesis of new materials. The molten salt systems investigated in this work were ionic liquids and eutectic mixtures of metal halide salts. The primary characterization methods included: SED-EDS, X-ray diffraction, SQUID magnetometry, Raman and solid state NMR. The main focus was on the magnetic

Parisa Mahjoor

2009-01-01

119

Research on self-propagating eutectic boriding  

Microsoft Academic Search

In this paper, preliminary research has been undertaken on self-propagating eutectic boriding. The results show that with boron carbide (B4C) as the boriding agent and heated by the energy released by thermite reaction during the process of self-propagating combustion, a layer of eutectic or hypoeutectic structure can be formed on the surface of steel with the thickness of up to

C. L. Ge; R. C. Ye

2002-01-01

120

Applications of molten salts in plutonium processing  

Microsoft Academic Search

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°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

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

1987-01-01

121

Electrode reaction of the Np3+\\/Np couple in LiClKCl eutectic melts  

Microsoft Academic Search

The electrochemical behaviour of the Np3+\\/Np couple in the LiClKCl eutectic salt was investigated by electromotive force measurements, cyclic voltammetry and chronopotentiometry in the temperature region between 723 and 823 K. The standard redox potential of the Np3+\\/Np couple vs Ag\\/AgCl (1.00 wt %) was measured and given by the equation, ENp3+\\/Np = -2.0298 + 0.000706 T, where E is

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

2001-01-01

122

Electrochemical behavior of actinide ions in LiClKCl eutectic melts  

Microsoft Academic Search

The electrodeposition and dissolution of uranium and plutonium in LiClKCl eutectic salt on tungsten and molybdenum working electrodes were investigated by cyclic voltammetry at 723, 773 and 823K. It is suggested from the voltammograms that the electrodeposition and dissolution of U and Pu, U3+\\/U and Pu3+\\/Pu, may be quasi-reversible, while the redox reaction of U4+\\/U3+ is reversible. The adsorption and

O. Shirai; T. Iwai; Y. Suzuki; Y. Sakamura; H. Tanaka

1998-01-01

123

Electrolysis of plutonium nitride in LiClKCl eutectic melts  

Microsoft Academic Search

The electrolysis of plutonium nitride, PuN, was investigated in the LiClKCl eutectic salt with 0.54 wt% PuCl3 at 773 K in order to understand the dissolution of PuN at the anode and the deposition of metal at the cathode from the viewpoint of the application of a pyrochemical process to nitride fuel cycle. It was found from cyclic voltammetry that

O. Shirai; T Iwai; K Shiozawa; Y Suzuki; Y Sakamura; T Inoue

2000-01-01

124

Electrolysis of Burnup-Simulated Uranium Nitride Fuels in LiCl-KCl Eutectic Melts  

Microsoft Academic Search

The electrochemical behavior of burnup-simulated uranium nitride fuels containing representative solid fission product elements, UN+Mo (Mo = 2.84 wt%), UN+Pd (Pd = 4.6 wt%) and (U, Nd)N (NdN = 8.0 wt%), was investigated in the molten LiCl-KCl eutectic salt with 0.54 wt% UCl3 in order to clarify the effects of fission products on the dissolution of actinide nitrides and the

Takumi SATOH; Takashi IWAI; Yasuo ARAI

2009-01-01

125

Properties of rapidly dissolving eutectic mixtures of poly(ethylene glycol) and fenofibrate: the eutectic microstructure.  

PubMed

Poly(ethylene glycol) or PEG is an ideal inactive component for preparing simple binary eutectic mixtures because of its low entropy of fusion ( approximately 0.0076 J/mol-K), lower melting point (approximately 62 degrees C) compared to most pharmaceuticals, miscibility with drugs at elevated temperatures, and its covalent crystalline lattice. Implication of these physicochemical properties on eutectic crystallization and size reduction of the drug is discussed. Enhancement of the dissolution rate of a poorly soluble compound through the formation of PEG-drug eutectics was investigated using fenofibrate. Solid dispersions of PEG-fenofibrate when characterized, revealed that PEG and fenofibrate form a simple eutectic mixture containing 20-25%(w/w) fenofibrate at the eutectic point. Eutectic crystallization led to the formation of an irregular microstructure in which fenofibrate crystals were found to be less than 10 microm in size. Dissolution rate improvement of fenofibrate correlated with the phase diagram, and the amount of fenofibrate released from the dispersions that contained fenofibrate as a eutectic mixture was at least 10-fold higher compared to untreated fenofibrate. On aging, the dissolution rate of the dispersion containing 15%(w/w) fenofibrate in PEG remained unaltered. The results indicate that PEG-drug eutectic formation is a valuable option for particle size reduction and subsequent dissolution rate improvement. PMID:12587112

Law, Devalina; Wang, Weili; Schmitt, Eric A; Qiu, Yihong; Krill, Steven L; Fort, James J

2003-03-01

126

Density measurements of the lithium fluoride/lithium sulfide eutectic at high temperature  

NASA Astrophysics Data System (ADS)

A straightforward and reliable method to determine densities of molten salts at high temperatures was de-veloped by Janz and Lorenz several years ago.[1] This method was followed in order to determine the density of the LiF/Li2S eutectic[2] over the temperature range of 1176 to 1355 K in which the eutectic is liquid. The rel-ative lack of data for this eutectic is surprising given its potential usefulness in the study of advanced batteries'31 and electrowinning of metals from molten sulfides.[41] The method is based on the fact that a solid piece of metal of known volume suspended from a pan balance into a molten salt will weigh less than if it were sus-pended in air at the same temperature. This difference in weight measured in grams will be equal to the buoyant force of the liquid at that temperature. The density of the salt bath can then readily be determined by dividing this difference by the volume of the solid piece of metal that is immersed in the bath. The procedure can be re-peated to give density values over a range of temperatures.

Lloyd, Charles L.; Gilbert, James B.

1994-10-01

127

Protease activation in glycerol-based deep eutectic solvents  

PubMed Central

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.

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

2011-01-01

128

Protease activation in glycerol-based deep eutectic solvents.  

PubMed

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

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

2011-11-01

129

Reactive eutectic brazing of nitinol  

NASA Astrophysics Data System (ADS)

Although NiTiNb alloys are well known as wide-hysteresis shape-memory alloys with important applications as coupling materials, the significance of one aspect of the Ni-Ti-Nb ternary system has not been fully appreciated. Based on the existence of a quasibinary NiTi-Nb eutectic isopleth in this ternary system, a novel braze method has been devised to fabricate metallurgical bonds between functional nitinol (NiTi) sections. When NiTi and pure Nb are brought into contact at temperatures above 1170C, spontaneous melting occurs, forming a liquid that is extremely reactive and not only wets NiTi surfaces, but also apparently dissolves oxide scales, obviating the need for fluxes and providing for efficient capillary flow into joint crevices. The melting process is diffusion-controlled and rate-limited by the diffusivity of Nb in the liquid. The braze liquid will subsequently solidify into microstructures containing predominantly ordered NiTi and disordered bcc-Nb. Mechanical tests revealed that the braze joints are strong, ductile, and biocompatible. With appropriate post-braze aging, the functional performance of the parent NiTi alloy can be restored. Micro-alloying the Nb fluer metal with Zr or tungsten showed great potential for solution-strengthening of the braze joints. For applications where biocompatibility is not an issue, Nb metal can be substituted by pure vanadium as the braze filler, which is demonstrated to possess tensile strengths that can be potentially superior to the Nb counterparts.

Low, Ke-Bin

130

CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES  

Microsoft Academic Search

Most of the tasks on the project have successfully been completed and reported. A 12 month no-cost extension has been requested to complete the remaining tasks. This report summarizes the accomplishments of the first six months of the no-cost extensions period. The acetic acid extraction showed that acetic acid has more effect on the extraction of the ternary catalyst (LNK)

Atul Sheth; Chandramouli Sastry

2001-01-01

131

CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES  

Microsoft Academic Search

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

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

2001-01-01

132

Temperature dependence of fluorescence for EuCl3 in LiCl-KCl eutectic melt.  

PubMed

The fluorescence of EuCl(3) in LiCl-KCl eutectic melt according to temperature changes was investigated, and the spontaneous partial reduction of Eu(3+) to Eu(2+) at high temperature was confirmed by the fluorescence results. The fluorescence decreases when the temperature increases, and this was examined in detail. The studies of fluorescence provided information regarding the chemical and physical behavior of europium ions in the molten salt according to the temperature changes. It is applicable for monitoring species and concentrations and estimating the approximate chemical structure of the ions in molten salts. PMID:20678668

Im, Hee-Jung; Kim, Tack-Jin; Song, Kyuseok

2010-06-25

133

Low-Temperature Synthesis of Lithium Manganese Oxide Using LiCl-Li2CO3 and Manganese Acetate Eutectic Mixture  

Microsoft Academic Search

Fine crystalline LiMn2O4 powders have been prepared by molten salt synthesis (MSS) at 500C, using an eutectic mixture of lithium chloride, lithium carbonate, and manganese acetate salts. Thermogravimetric and differential thermal analysis (TGA\\/DTA) measurements are performed to investigate the thermal decomposition behavior of the precursor salts. The single-phase cubic structure of LiMn2O4 is confirmed by X-ray powder diffraction analysis. The

M. Helan; L. John Berchmans

2011-01-01

134

Eutectic nucleation in hypoeutectic Al-Si alloys  

SciTech Connect

The nucleation mechanism of eutectic grains in hypoeutectic Al-Si foundry alloys has been investigated by examining deep etched specimens in high-resolution field emission gun scanning electron microscope (FEG-SEM) and by using in-situ Focused Ion Beam (FIB) milling and microscopy. Both unmodified and Sr-modified alloys were studied to characterize the nucleation mechanism of eutectic silicon flakes and fibers. It is proposed that following nucleation of eutectic Al on the primary {alpha}-Al dendrites, fine Si particles form at the solidification front upon which the eutectic Si flakes and fibers could develop. The formation of small Si particles is attributed to Si enrichment of the remaining melt due to the formation of eutectic Al (aluminum spikes) at the eutectic temperature. A hypothesis is then proposed to explain the mechanism of eutectic grains formation with main emphasis on the eutectic Si phase.

Nafisi, S. [Facility for Electron Microscopy Research, McGill University, 3640 University St., Montreal, QC, H3A 2B2 (Canada)], E-mail: snafisi@ipsco.com; Ghomashchi, R. [Advanced Materials and Processing Research Institute, Suite 122, A7-1390 Major MacKenzie, ON, L4S 0A1 (Canada); Vali, H. [Facility for Electron Microscopy Research, McGill University, 3640 University St., Montreal, QC, H3A 2B2 (Canada)

2008-10-15

135

Eutectic growth under acoustic levitation conditions.  

PubMed

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

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

2002-12-10

136

Tin-silver-copper eutectic temperature and composition  

Microsoft Academic Search

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

M. E. Loomans; M. E. Fine

2000-01-01

137

Thermomigration in eutectic SnPb alloy  

NASA Astrophysics Data System (ADS)

The thermomigration (TM) behavior in eutectic SnPb alloy was observed under a constant thermal gradient of 1000 C/cm. Pb phase was depleting in the hot side, so Pb atom should be the dominant migration species in the current studied conditions. By estimating the depletion atomic volume in the hot side, TM atomic flux in SnPb was estimated to be 7.021013 atoms/cm2 s. The important TM parameter, the molar heat flux (Q*), of eutectic SnPb alloy was obtained and found to be 22.16 kJ/mole.

Chuang, Y. C.; Liu, C. Y.

2006-04-01

138

Mass-Transfer Characteristics of Nitrate-Based Salt Mixtures.  

National Technical Information Service (NTIS)

Molten eutectic NaNO sub 3 -KNO sub 3 is being circulated in three thermal-convection loops constructed of alloy 800 and types 304L and 316 stainless steel. The loops are operated at a maximum salt temperature of 595 exp 0 C and a salt temperature differe...

J. H. DeVan P. F. Tortorelli

1980-01-01

139

Calculation of Binary Eutectic Phase Diagrams.  

National Technical Information Service (NTIS)

The phase diagrams of 65 simple binary eutectic phase diagrams are calculated from the properties of the elemental constituents. The liquid phase is assumed to behave as an ideal solution and the terminal solid solution regions were assumed to be ideal an...

J. E. Davison

1969-01-01

140

STUDIES ON METALLIC THORIUM PRODUCTION FROM KOREAN MONAZITE SAND. PART 5. METALLIC THORIUM PRODUCTION BY FUSED SALTS ELECTROLYSIS  

Microsoft Academic Search

Metallic thorium production was attempted by fused salts electrolysis in ; an argon atmosphere, using the thorium fluoride double salts system. The ; electrolyte was pure thorium salts obtained from processing Korean monazite sands ; through alkali decomposition and solvent extraction. The bath content consisted ; of sodium chloride -potassium chloride and thorium salt eutectic. Relations ; between current densities,

D. Kim; J. Lee; H. Lee

1960-01-01

141

Pb-free Sn-Ag-Cu ternary eutectic solder  

DOEpatents

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.

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

1996-06-18

142

Effect of Additives on Performance on Hydrated-Salt TES Systems.  

National Technical Information Service (NTIS)

Calmac's objectives under this contract will be to evaluate a gelling agent, developed by Calor, Ltd. of England, as a means of preventing stratification in sodium thiosulfate pentahydrate and Glauber salt eutectic phase change materials; to determine tec...

C. D. MacCracken

1981-01-01

143

Hygroscopic Salts on Mars  

NASA Astrophysics Data System (ADS)

We present preliminary results on the influence of a salt-rich regolith in the water cycle of Mars. Global climate modeling shows that the relative humidity on the Martian surface often reaches values above the deliquescence point of salts that are common components of the regolith. At the deliquescence point, these salts will absorb atmospheric water vapor and form a saturated, transient liquid solution that is stable under a range of temperatures. If atmospheric temperatures fall below the eutectic point of the solution, the later will freeze in the pore space of the regolith, thereby resulting in a net transport of water from the vapor phase in the atmosphere, to the solid state in the regolith. This simple model partially accounts for some the distribution of water on the Martian surface as revealed by Mars Odyssey, in particular, we find that: even though the Cl and surface water distributions detected by HEND/ODYSSEY are highly correlated, salt deliquescence under the the present atmospheric conditions does not explain the overall distribution of water in the near surface regolith. However deliquescence of salt-rich soils could be an important contributor to the distribution of water in the regolith at high obliquity. In that scenario the water in the near-surface regolith would be the remnant of high obliquity conditions salt deliquescence is still active in different regions on Mars today, and it should be introduced as a parameter in the modern GCMs as a new ground/atmosphere interaction

Melchiorri, R.; Davila, A. F.; Chittenden, J.; Haberle, R. M.

2008-12-01

144

Salt River Salt Banks.  

National Technical Information Service (NTIS)

The Salt River Salt Banks are located on the north shore of the Salt River on the Fort Apache Indian Reservation. Three small springs emerge above and flow over the salt banks resulting in the formation of stalactites. The mechanism by which the banks wer...

E. L. Smith G. L. Bender

1973-01-01

145

Two-stage eutectic metal brushes  

DOEpatents

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.

Hsu, John S (Oak Ridge, TN)

2009-07-14

146

Thermomigration in eutectic SnPb alloy  

Microsoft Academic Search

The thermomigration (TM) behavior in eutectic SnPb alloy was observed under a constant thermal gradient of 1000 C\\/cm. Pb phase was depleting in the hot side, so Pb atom should be the dominant migration species in the current studied conditions. By estimating the depletion atomic volume in the hot side, TM atomic flux in SnPb was estimated to be 7.021013

Y. C. Chuang; C. Y. Liu

2006-01-01

147

Aluminum arsenide eutectic gallium arsenide solar cell  

Microsoft Academic Search

An improved gallium arsenide solar cell is provided by forming a P+ layer on top of a wafer of vertical PN junction eutectic gallium arsenide crystal by liquid phase epitaxial growth of P doped GaAs followed by liquid phase epitaxial growth at Al(x)AsGa(1-x) on the surface of the vertical PN junction substrate. The deposited GaAs layer with P dopant and

Rahilly

1976-01-01

148

Aluminum arsenide eutectic gallium arsenide solar cell  

Microsoft Academic Search

An improved gallium arsenide solar cell is provided by forming a P + layer on top of a wafer of plural vertical PN junction eutectic gallium arsenide crystal by liquid phase epitaxial growth of P doped GaAs followed by liquid phase epitaxial growth at Al\\/sub x\\/AsGa\\/sub l-x\\/ on the surface of the vertical PN junction substrate. The deposited GaAs layer

Rahilly

1978-01-01

149

Adsorption of eutectic LiCl-KCl into zeolite 4A using a mechanically fluidized vacuum system  

Microsoft Academic Search

A high-temperature mixer has been used to absorb LiCl-KCl eutectic salt powders into zeolite 4A. In situ sampling has been performed, allowing for a time-resolved view of the adsorption reaction. The weight percent free (nonabsorbed) chloride ions has been used as a measure of the effectiveness of the adsorption process. Using zeolite 4A powder with no binder, the free chloride

Michael F. Simpson; Terry J. Battisti

1999-01-01

150

Evaluation of 2.25Cr1Mo Alloy for Containment of LiCl\\/KCl Eutectic during the Pyrometallurgical Processing of Used Nuclear Fuel  

Microsoft Academic Search

Recovery of uranium from the Mk-IV and Mk-V electrorefiner vessels containing a LiCl\\/KCl eutectic salt has been on-going for 14 and 12 years, respectively, during the pyrometallurgical processing of used nuclear fuel. Although austenitic stainless steels are typically utilized for LiCl\\/KCl salt systems, the presence of cadmium in the Mk-IV electrorefiner dictates an alternate material. A 2.25Cr-1Mo alloy (ASME SA-387)

B. R. Westphal; S. X. Li; G. L. Fredrickson; D. Vaden; T. A. Johnson; J. C. Wass

2011-01-01

151

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

PubMed

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

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

2011-01-31

152

Fundamental Properties of Salts  

SciTech Connect

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.

Toni Y Gutknecht; Guy L Fredrickson

2012-11-01

153

A study of freezing and melting with eutectic interactions  

NASA Astrophysics Data System (ADS)

The phenomenon of freezing and melting following sudden constant between a pool of binary eutectic-forming solution and an underlying solid layer of the lighter pool component was investigated. Experiments were conducted using various salt (Kl, NaCl, MgCl2, or CaCl2) solutions as the pool and air-bubble-free ice as the solid. Both the melting regime and the selective freezing regime were studied. Experimentally, the temperature transients and the phase-change rates were measured and the interface morphology as well as the micro-physical process near the phase-change front were observed. In the selective freezing study, the growth of a solid-liquid two phase region over a subcooled ice slab was investigated. Assuming that each infinitesimal element of the two-phase region is in local thermodynamic equilibrium with the solid and that the solid is semi-infinite in extent, a similarity model was developed to predict the dependence of the freezing rate and temperature distribution on the parameters of the system.

Fang, L. J.

1984-12-01

154

Molten salt synthesis of potassium hexatitanate  

NASA Astrophysics Data System (ADS)

Potassium hexatitanate fibrous crystals have been synthesized by a conventional solid-state reaction and via molten salt process. The molten salt process has been shown to be effective in preparing fine and non-agglomerated K2Ti6O13 whiskers. The type of molten salt (KCl, NaCl-KCl) has a significant effect on the chemical composition of the whiskers. By using a eutectic mixture of NaCl and KCl, the replacement of potassium ions in solid potassium hexatitanate by smaller sodium ions from the chloride flux can be achieved. The characterization of the samples was carried out by means of XRD, SEM, EDX and WDX.

Zaremba, T.

2012-09-01

155

Viscosity measurement of molten carbonate salt  

SciTech Connect

This report describes research on the eutectic property values of lithium/sodium/potassium carbonate. This carbonate eutectic is the leading candidate for high-temperature heat transfer fluids for a direct-absorption receiver concept being researched at the Solar Energy Research Institute (SERI) for solar thermal central receiver systems. Measurements of the absolute viscosity of the carbonate eutectic were taken and compared to the results from previously published data. Two samples were tested: a ternary eutectic prepared from Reagent Grade quality components and a ternary eutectic prepared from Commercial Grade quality components. For each sample the absolute viscosity was determined with accuracy limits of Congruent to +- 3%, and at five temperatures: 500/sup 0/, 600/sup 0/, 700/sup 0/, 900/sup 0/, and 900/sup 0/C (+-5/sup 0/C). Some limited measurements using materials having calibration quality data sets were included as a check on the accuracy limits. Both samples were provided by SERI along with reports of analyses and purity specifications for the component carbonate salts. This report gives results of these measurements, together with a complete account of the measurement technique, a description of the high-temperature viscometer facility, and the error analyses and accuracy statements. An appendix gives details on sample qualities, numerical data sets from measurements, and graphical analyses.

Janz, G.J.

1986-09-01

156

Synthesis and Electronic Applications of Oxide-Metal Eutectic Composites.  

National Technical Information Service (NTIS)

A review is given of important developments in the synthesis of oxide-metal eutectic composites and the composite application in the continuing development of field emitters. Known metal oxide-metal binary and ternary eutectic systems are listed. The synt...

J. D. Holder J. K. Cochran D. N. Hill A. T. Chapman G. W. Clark

1980-01-01

157

ELECTRODE POTENTIALS IN MOLTEN LITHIUM SULFATE-POTASSIUM SULFATE EUTECTIC  

Microsoft Academic Search

The lithium sulfate --potassium sulfate eutectic (80% lithium sulfate by ; mole; melting point 535 deg ) was shown to be an adequate molten solvent for ; electrochemical investigations at 625 deg . A procedure for preparing the ; eutectic melt was established. The silver(I) --silver(0) system was found to be ; a satisfactory reference electrode in this melt. The

C. H. Liu

1962-01-01

158

Conditioning of Waste LiCl Salt from Pyrochemical Process Using Zeolite A  

Microsoft Academic Search

The electrolytic (LiCl-LiO) reduction process (Advanced spent fuel Conditioning Process; ACP) and the electrorefining process, which are being developed by the Korea Atomic Energy Research Institute (KAERI), are to generate two types of molten salt wastes such as a LiCl salt and a LiCl-KCl eutectic salt, respectively. These waste salts must meet certain criteria for a disposal. A conditioning process

J. G. Kim; J. H. Lee; E. H. Kim; D. H. Ahn; J. H. Kim

2006-01-01

159

Separation of adhered salt from uranium deposits generated in electro-refiner  

Microsoft Academic Search

It is important to increase a throughput of the salt removal process from uranium deposits which is generated on the solid\\u000a cathode of electro-refiner in pyroprocess. In this study, it was proposed to increase the throughput of the salt removal process\\u000a by the separation of the liquid salt prior to the distillation of the LiClKCl eutectic salt from the uranium

S. W. KwonK; K. M. Park; H. G. Ahn; H. S. Lee; J. G. Kim

2011-01-01

160

Surface chemical properties of eutectic and frozen NaCl solutions probed by XPS and NEXAFS.  

PubMed

We study the surface of sodium chloride-water mixtures above, at, and below the eutectic temperature using X-ray photoelectron spectroscopy (XPS) and electron-yield near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The NaCl frozen solutions are mimicking sea-salt deposits in ice or snow. Sea-salt particles emitted from the oceans are a major contributor to the global aerosol burden and can act as a catalyst for heterogeneous chemistry or as cloud condensation nuclei. The nature of halogen ions at ice surfaces and their influence on surface melting of ice are of significant current interest. We found that the surface of the frozen solution, depending on the temperature, consists of ice and different NaCl phases, that is, NaCl, NaCl2H(2)O, and surface-adsorbed water. PMID:20954232

K?epelov, Adla; Huthwelker, Thomas; Bluhm, Hendrik; Ammann, Markus

2010-12-17

161

SOLVENT EXTRACTION OF ACTINIDES AND LANTHANIDES FROM MOLTEN SALTS  

Microsoft Academic Search

Quantitative measurements were made of distribution coefficients of ; metal ions between a fused salt phase and an organic phase for the first time. ; The measurements were made at a temperature of l50 deg C using a LiNO- KNO\\/; sub 3\\/ eutectic (m.p. 120 deg C) and tributyl phosphate (TBP) as the active ; extractant with a mixture of

N. M. Isaac; P. R. Fields; D. M. Gruen

1961-01-01

162

Incineration in molten salts of alpha-contaminated solid waste  

Microsoft Academic Search

Incineration by the molten salt process is found to be suitable for the safe destruction of alpha-contaminated waste without pollution but with the possibility of plutonium recovery. A detailed description of the processes involved in the incineration process is given covering: combustion, acid dissolution, recovery of U and\\/or Pu by electrolytic means, separation of ash, and recycling of the eutectic

G. Brambilla; E. Quercioli; L. Beaulardi; R. Gritti

2008-01-01

163

Exploratory corrosion tests on alloys in molten salts at 900 C  

Microsoft Academic Search

The results of exploratory corrosion tests on sixteen different alloys at 900 C in molten eutectic sodium-potassium carbonate, in molten eutectic sodium-potassium-magnesium chloride and in molten sodium hydroxide are presented. The salts and many of the alloys were chosen for this study based on results reported in the literature; other alloys that were tested had no previously reported testing in

R. T. Coyle; R. W. Burrows; T. M. Thomas; G. Y. Lai

2008-01-01

164

Containerless solidification of acoustically levitated Ni-Sn eutectic alloy  

NASA Astrophysics Data System (ADS)

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.

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

2012-10-01

165

SEPARATION OF METAL SALTS BY ADSORPTION  

DOEpatents

It has been found that certain metal salts, particularly the halides of iron, cobalt, nickel, and the actinide metals, arc readily absorbed on aluminum oxide, while certain other salts, particularly rare earth metal halides, are not so absorbed. Use is made of this discovery to separate uranium from the rare earths. The metal salts are first dissolved in a molten mixture of alkali metal nitrates, e.g., the eutectic mixture of lithium nitrate and potassium nitrate, and then the molten salt solution is contacted with alumina, either by slurrying or by passing the salt solution through an absorption tower. The process is particularly valuable for the separation of actinides from lanthanum-group rare earths.

Gruen, D.M.

1959-01-20

166

Effects of heating on salt-occluded zeolite  

Microsoft Academic Search

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,

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

1996-01-01

167

Mass-transfer characteristics of nitrate-based salt mixtures  

NASA Astrophysics Data System (ADS)

Molten eutectic NaNO3-KNO3 was being circulated in three thermal convection loops constructed of alloy 800 and types 304L and 316 stainless steel. The loops were operated at a maximum salt temperature of 595 C and a salt temperature differential of 235 C. Corrosion specimens contained within each loop were withdrawn for periodic determinations of weight and microstructural changes. Salt samples were analyzed at selected intervals to monitor changes in the composition of the salt. Controlled potential voltammetry was also used. Results indicate low corrosion rates for the austenitic stainless steels in flowing NaNO3-KNO3.

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

1981-03-01

168

Method for the production of uranium chloride salt  

DOEpatents

A method for the production of UCl.sub.3 salt without the use of hazardous chemicals or multiple apparatuses for synthesis and purification is provided. Uranium metal is combined in a reaction vessel with a metal chloride and a eutectic salt- and heated to a first temperature under vacuum conditions to promote reaction of the uranium metal with the metal chloride for the production of a UCl.sub.3 salt. After the reaction has run substantially to completion, the furnace is heated to a second temperature under vacuum conditions. The second temperature is sufficiently high to selectively vaporize the chloride salts and distill them into a condenser region.

Westphal, Brian R.; Mariani, Robert D.

2013-07-02

169

Interaction of ?-silicon carbide with lead-lithium eutectic  

NASA Astrophysics Data System (ADS)

Compatibility of silicon carbide with molten lead-lithium eutectic has been studied by differential scanning calorimetry (DSC) and prolonged heating of ? - SiC pellet in molten Pb-17Li eutectic alloy at 823K. Multiple peaks were present in the DSC analysis. However, XRD analysis has not shown any new phase formation, which indicated that no chemical reaction occurred. An experiment have also been carried out by dipping ? - SiC pellet in molten Pb-17Li eutectic alloy at 823K for 500 h to check the solubility of ? - SiC in molten Pb-17Li. Substantial mass loss of ?-SiC pellet was observed which could be due to dissolution of ?-SiC or its component into the eutectic melt.

Chakraborty, Poulami; Kumar, Sanjay; Fotedar, Ram Kishen; Krishnamurthy, Nagaiyar

2013-06-01

170

Corrosion of ODS steels in leadbismuth eutectic  

Microsoft Academic Search

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 leadbismuth eutectic cooled reactors and spallation sources. Corrosion tests on five different ODS alloys were performed in flowing liquid leadbismuth eutectic

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

2008-01-01

171

Containerless solidification of undercooled oxide and metallic eutectic melts  

Microsoft Academic Search

A high-speed video was employed to monitor the in situ recalescence of undercooled oxide Al2O336.8at.% ZrO2 and metallic Ni18.7at.% Sn eutectics that were processed on an aero-acoustic levitator and an electromagnetic levitator, respectively. For the oxide eutectic, the entire sample becomes brighter and brighter without any clear recalescence front during spontaneous crystallization. When the sample was seeded at desired undercoolings,

Mingjun Li; Kosuke Nagashio; Kazuhiko Kuribayashi

2004-01-01

172

Adsorption of eutectic LiCl-KCl into zeolite 4A using a mechanically fluidized vacuum system  

SciTech Connect

A high-temperature mixer has been used to absorb LiCl-KCl eutectic salt powders into zeolite 4A. In situ sampling has been performed, allowing for a time-resolved view of the adsorption reaction. The weight percent free (nonabsorbed) chloride ions has been used as a measure of the effectiveness of the adsorption process. Using zeolite 4A powder with no binder, the free chloride concentration leveled off at 0.4--0.5 wt % in less than 5 h at 500 C. Zeolite 4A granules ({minus}60 + 200 mesh) containing binder yielded a free chloride concentration of 0.02 wt % after 5 h at 500 C. It is concluded that the improved performance from the granulated zeolite can be attributed to better mixing within the retort. A 50% reduction in the free chloride concentration below the melting point of the salt suggests that solid-state adsorption of the salt into the zeolite is possible.

Simpson, M.F.; Battisti, T.J. [Argonne National Lab., Idaho Falls, ID (United States)

1999-06-01

173

[Microcalorimetric study of thermodynamic values of aqueous phase transition and eutectic melting in the binary and ternary systems Na-DNA--H20 and Na-DNA--H20--NaCl].  

PubMed

Thermodynamic parameters of water phase transition and eutectics melting in DNA water-salt solution were studied by means of low temperature scanning differential microcalorimetry at different concentrations of polyanions. DNA hydration was measured and the character of changes in Na+ counterion binding was revealed during the transition of double helix into the state of random coils. PMID:678564

Mrevlishvili, G M; Dzhaparidze, G Sh; Sokhadze, V M; Chanchalashvili, Z I; Bilinska, B

174

Ultrasound in lead-bismuth eutectic  

SciTech Connect

The Belgian Nuclear Research Centre (SCK.CEN) is in the process of designing MYRRHA, a new multi-purpose irradiation facility to replace the ageing BR2. MYRRHA is a fast spectrum reactor cooled with lead-bismuth eutectic (LBE). As liquid metal is opaque to visual light, ultrasonic measurement techniques are selected to fulfill essential tasks that, according to our assessment, will be demanded by licensing authorities, in particular: fuel assembly identification and localization of a lost fuel assembly. To that end, a considerable research effort at SCK.CEN is devoted to study ultrasonic propagation in LBE. As ultrasonic experiments in LBE are elaborate and expensive to set up, we are particularly interested in to what extent experiments in water can be extrapolated to LBE - one of the main focuses of this article. We describe and present results of a first experiment with this goal which shows that the signal to noise ratio is better in LBE and that we even see small diffuse reflections up to 40 deg. off normal. On the other hand, we do not see internal reflections in stainless steel objects in LBE which we do in water. Therefore, we conclude that experiments in water can be used to validate algorithms for LBE on the condition that they do not rely on internal reflections. We also present solutions to tackle the essential tasks: fuel assembly identification and lost object localization. The requirements for the ultrasonic equipment implementing these solutions are also discussed. (authors)

Dierckx, M.; Van Dyck, D. [SCK.CEN, Belgian Nuclear Research Centre, Boeretang 200, BE-2400, Mol (Belgium)

2011-07-01

175

Are deep eutectic solvents benign or toxic?  

PubMed

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

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

2012-11-28

176

Investigation of the evaporation of rare earth chlorides in a LiClKCl molten salt  

Microsoft Academic Search

Uranium dendrites which were deposited at a solid cathode of an electrorefiner contained a certain amount of salts. These\\u000a salts should be removed for the recovery of pure metal using a cathode processor. In the uranium deposits from the electrorefining\\u000a process, there are actinide chlorides and rare earth chlorides in addition to uranium chloride in the LiClKCl eutectic salt.\\u000a The

Sung Bin Park; Dong Wook Cho; Moon Sik Woo; Sung Chan Hwang; Young Ho Kang; Jeong Guk Kim; Hansoo Lee

2011-01-01

177

Complexes responsible for ionic transport in LiCl-KCl eutectic melt  

SciTech Connect

DFT calculations using DMol software at the DNP/UHF/BLYP level were firstly performed in order to determine the more stable isolated chloro-complexes of lithium and/or potassium cations. An Inverse Isotropic Monte Carlo technique was then used for obtaining a 3-D model of this melt from the pair correlation functions computed by Lantelme and Turq. At last, DFT calculation derived complexes were looked for in the melt model using a lab-made software. This procedure showed the presence of LiCl{sub 2{sup {minus}}} and K{sub 2}Cl{sup +} complexes in molten KCl eutectic. This procedure allows a better understanding of the structure of melt and suggests answers to some phenomena that occur in molten salts such as the Chemla effect. {copyright} {ital 1996 American Institute of Physics.}

Hebant, P.; Picard, G.S. [Laboratoire d`Electrochimie et de Chimie Analytique (URA 216), Ecole Nationale Superieure de Chimie de Paris, 11 rue P & M Curie, 75231 Paris Cedex 05 (France); Mouron, L.; Legendre, J. [Laboratoire de Modelisation Appliquee a la Chimie]|[Ecole Nationale Superieure de Chimie de Paris, 11 rue P & M Curie, 75231 Paris Cedex 05 (France)

1996-04-01

178

High-temperature molten salt thermal energy storage systems for solar applications  

NASA Astrophysics Data System (ADS)

Alkali and alkaline earth carbonate latent-heat storage salts, metallic containment materials, and thermal conductivity enhancement materials were investigated to satisfy the high temperature (704 to 871 C) thermal energy storage requirements of advanced solar-thermal power generation concepts are described. Properties of the following six salts selected for compatibility studies are given: three pure carbonates, K2CO3, Li2CO3 and Na2CO3; two eutectic mixtures, BaCO3/Na2CO3 and K2CO3/NaCO3, and one off-eutectic mixture of Na2CO3/K2CO3.

Petri, R. J.; Claar, T. D.

1980-03-01

179

Salt tectonics  

SciTech Connect

Salt deposits have economic significance because of their importance as oil and gas traps and their potential as radioactive waste disposal sites. This article reviews the formation of salt domes, beginning with a description of the formation of salt deposits as evaporites and a discussion of early attempts to model the development of salt domes. Current work on tectonics of salt dome formation and related tectonics is then discussed in detail.

Talbot, C.J.; Jackson, M.P.A.

1988-01-01

180

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

NASA Astrophysics Data System (ADS)

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 eutecticmixture of anomalous and regular structuresregular 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.

Zhai, Wei; Hong, Zhenyu; Wei, Bingbo

2007-08-01

181

Transient and steady state creep response of ice I and magnesium sulfate hydrate eutectic aggregates  

Microsoft Academic Search

Ice\\/hydrate eutectic aggregates are much stronger than pure ice at low stressAt high stress, eutectic aggregates display semibrittle behaviorA semibrittle icy shell would require less stress to form folds and cracks

Christine McCarthy; Reid F. Cooper; David L. Goldsby; William B. Durham; Stephen H. Kirby

2011-01-01

182

Effect of amino acids on the eutectic behavior of NaCl solutions studied by DSC.  

PubMed

The effect of a series of amino acids on the eutectic behavior of NaCl solutions at isotonic concentration has been studied by differential scanning calorimetry. The inclusion of different amino acids had different effects on eutectic formation. The amino acids were grouped into four categories based on their effect on eutectic formation: category C were amino acids that had no effect on eutectic formation; category D amino acids inhibited eutectic formation; category T amino acids shifted the melting of the eutectic to a lower temperature; category E amino acids caused the formation of a new eutectic with a melting temperature approximately -5 degrees C. The mechanism of these different effects on eutectic behavior is discussed, based on the chemical structure of the amino acids. PMID:15925578

Chen, N J; Morikawa, J; Hashimoto, T

2005-04-09

183

Thermoelectric parameters of eutectic Ge-InAs alloy  

SciTech Connect

If a semiconductor is made as an alloy containing small inclusions (a few micrometers), one expects that the size of the composition-inhomogeneity regions would be reduced, with corresponding changes in the thermoelectric parameters by comparison with large single crystals (several centimeters). This has been tested with a eutectic InAs-Ge alloy containing small germanium inclusions. The eutectic alloys were made my Bridgmans method. The conductivity and thermo-emf parallel and perpendicular to the axis were measured along with the thermal conductivity at 298-940 K. The parameters were affected by Ga acceptor and Sb and Te donors.

Leonov, V.V.; Gantimurova, Z.K.

1988-04-01

184

Palladium-Carbon Eutectic Fixed Point for Thermocouple Calibration  

NASA Astrophysics Data System (ADS)

A Pd-C eutectic fixed point has been produced using a molybdenum disilicide element, electrically heated furnace that was built in-house. The eutectic fixed point was measured with two Pt/Pd thermocouples calibrated at the fixed points of Sn, Zn, Al, Ag, and Au. An ITS-90 temperature of (1490.69 0.88) C ( k = 2) was obtained for the inflection point of the melting plateau. Diffusion of Pd into the thermowell and onto the thermocouple protection tube was observed.

Todd, A. D. W.; Gotoh, M.; Woods, D. J.; Hill, K. D.

2011-01-01

185

Lead-bismuth eutectic technology for Hyperion reactor  

NASA Astrophysics Data System (ADS)

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.

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

2013-10-01

186

Cobalt-Carbon Eutectic Fixed Point for Contact Thermometry  

NASA Astrophysics Data System (ADS)

Two Co-C eutectic fixed points were constructed for thermocouple calibration. The eutectic fixed points were measured with a Pt/Pd thermocouple calibrated at the freezing temperatures of Sn, Zn, Al, Ag, and Au. A temperature of (1323.99 0.52) C ( k = 2) was determined via this method. The cell design allowed filling to be accomplished in a single step. Each cell was held above 1300 C for at least 42 h and was subjected to at least 20 melt/freeze cycles with no mechanical failure occurring.

Todd, A. D. W.; Gotoh, M.; Woods, D. J.; Hill, K. D.

2011-01-01

187

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

SciTech Connect

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.

Jian, Xiaogang [ORNL; Han, Qingyou [ORNL

2006-01-01

188

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

Microsoft Academic Search

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.

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

2006-01-01

189

The thermal conductivity of the molten NaNO3-KNO3 eutectic between 525 and 590 K  

NASA Astrophysics Data System (ADS)

Molten salts are one of the few remaining classes of fluids for which standardquality (1% accuracy) data on thermal conductivity have not hitherto been available. We have therefore developed a new apparatus based on the transient hot-wire technique to obtain reference-quality measurements of the thermal conductivity of molten salts at high temperatures. Liquid metal-filled quartz capillaries served as insulated hot wires in our method, and in addition, a two-wire technique was used in order to obtain absolute values of the thermal conductivity. New data for the NaNO3-KNO3 eutectic between 525 and 590 K are reported in this paper and comparisons with other recent measurements are shown.

Diguilio, R. M.; Teja, A. S.

1992-07-01

190

Microstructural evolution of eutectic Au-Sn solder joints  

SciTech Connect

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.

Song, Ho Geon

2002-05-31

191

Use of Microgravity to Control the Microstructure of Eutectics.  

National Technical Information Service (NTIS)

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 i...

W. R. Wilcox L. L. Regel R. W. Smith

1998-01-01

192

Mechanical behaviour of the Cd-Zn eutectic composite  

Microsoft Academic Search

The structure and the resultant mechanical properties of the unidirectionally solidified Cd-Zn eutectic have been examined over a wide range of growth rates. The yield and ultimate strengths when tested in tension and compression were found to increase monotonically with the growth rate. The deformation of the matrix in tension occurred mostly by twinning whereas slip-controlled deformation was observed in

M. Sahoo; R. A. Porter; R. W. Smith

1976-01-01

193

Electrochemical method of producing eutectic uranium alloy and apparatus  

Microsoft Academic Search

An apparatus and method for continuous production of liquid uranium alloys through the electrolytic reduction of uranium chlorides. The apparatus includes an electrochemical cell formed from an anode shaped to form an electrolyte reservoir, a cathode comprising a metal, such as iron, capable of forming a eutectic uranium alloy having a melting point less than the melting point of pure

James A. Horton; H. Wayne Hayden

1995-01-01

194

Electrochemical method of producing eutectic uranium alloy and apparatus  

Microsoft Academic Search

An apparatus and method are disclosed for continuous production of liquid uranium alloys through the electrolytic reduction of uranium chlorides. The apparatus includes an electrochemical cell formed from an anode shaped to form an electrolyte reservoir, a cathode comprising a metal, such as iron, capable of forming a eutectic uranium alloy having a melting point less than the melting point

J. A. Horton; H. W. Hayden

1995-01-01

195

Devitrification studies of wollastonite-tricalcium phosphate eutectic glass.  

PubMed

The present paper describes and discusses the devitrification and crystallization process of wollastonite-tricalcium phosphate (W-TCP) eutectic glass. This process was studied in situ from room temperature up to 1375 degrees C, by neutron diffractometry in vacuum. The data obtained were combined and compared with those performed in ambient atmosphere by differential thermal analysis and with those of samples fired in air at selected temperatures, and then cooled down and subsequently studied by laboratory XRD and field emission scanning electron microscopy fitted with energy X-ray dispersive spectroscopy. The experimental evidence indicates that the devitrification of W-TCP eutectic glass begins at approximately 870 degrees C with the crystallization of a Ca-deficient apatite phase, followed by wollastonite-2M (CaSiO(3)) crystallization at approximately 1006 degrees C. At 1375 degrees C, the bio-glass-ceramic is composed of quasi-rounded colonies formed by a homogeneous mixture of pseudowollastonite (CaSiO(3)) and alpha-tricalcium phosphate (Ca(3)(PO(4))(2)). This microstructure corresponds to irregular eutectic structures. It was also found that it is possible to obtain from the eutectic composition of the wollastonite-tricalcium phosphate binary system a wide range of bio-glass-ceramics, with different crystalline phases present, through appropriate design of thermal treatments. PMID:19427932

Magallanes-Perdomo, M; Pena, P; De Aza, P N; Carrodeguas, R G; Rodrguez, M A; Turrillas, X; De Aza, S; De Aza, A H

2009-05-04

196

Semiconductor-Metal Eutectic Composites for High Power Switching.  

National Technical Information Service (NTIS)

This report reviews the accomplishments of a research program that sought to develop a totally new material for high-power transistor switching. The material, which we have generally referred to as SME for semiconductor-metal eutectic, is a composite with...

Q. Nguyen P. Rossoni M. Levinson B. M. Ditchek

1992-01-01

197

Reduction of voiding in eutectic ball grid array solder joints  

Microsoft Academic Search

The rapid progress of ball grid array (BGA) component technology has served to alleviate many problems associated with the placement and soldering of high lead count, fine pitch surface mount technology (SMT) packages. An unfortunate result of this process, however, is the occurrence of voids in the interconnecting eutectic solder balls of these packages. Large voids can affect the mechanical

William Casey

1999-01-01

198

Improving fatigue life in near-eutectic Sn Pb solders  

Microsoft Academic Search

Due to technical advances in packaging technology, solder joint thermal shear fatigue failures pose reliability concerns and limit current packaging designs in the electronics industry. Past work has shown that thermal fatigue failures, as well as isothermal fatigue and creep failures, in the commonly used near-eutectic Sn-Pb solders are preceded by the formation of a band of coarsened material. Examination

Summers

1991-01-01

199

Salt precipitation during the freeze-concentration of phosphate buffer solutions.  

PubMed

Salt precipitation during the freeze concentration of phosphate solutions was investigated by differential scanning calorimetry (DSC), in view of its practical importance in the cryopreservation or freeze-drying of biological materials. It was found that the fraction of salt precipitated depends on the initial salt concentration; it began to decrease with decreasing concentration at approx. 1 M. Salt precipitation also depends on the cooling rate. In some cases, cooling at approx. 10(3) degree min-1 inhibited salt precipitation which had been observed during slow cooling (0.62 degree min-1), without, however, affecting the shape of the ice melting endotherm. In the case of ternary phosphate buffers, the fraction of salt precipitating depends on the salt composition as well as the initial concentration and cooling rate. Near the composition of the ternary eutectic or the composition where two salts are present at the same concentration, salts were prevented from precipitation. PMID:2611352

Murase, N; Franks, F

1989-11-01

200

Thermal energy storage by means of the latent heat of fusion of a mineral salt - Study of a direct contact dynamic exchanger with salt crystallization during flow  

Microsoft Academic Search

The use of a heat exchanger in which the storage medium (a mineral salt) comes into direct contact with the heat transfer agent for the recovery of thermal energy stored in molten salt is investigated. Preliminary experiments on heat transfer and phase separation in a mixture of a molten NaNO2, NaNO3, KNO3 eutectic (melting point 142 C) with a synthetic

J. Pantaloni; O. Favre; R. Bailleux; G. Finiels; J. Marchisio

1979-01-01

201

Salt Tolerance  

PubMed Central

Studying salt stress is an important means to the understanding of plant ion homeostasis and osmo-balance. Salt stress research also benefits agriculture because soil salinity significantly limits plant productivity on agricultural lands. Decades of physiological and molecular studies have generated a large body of literature regarding potential salt tolerance determinants. Recent advances in applying molecular genetic analysis and genomics tools in the model plant Arabidopsis thaliana are shading light on the molecular nature of salt tolerance effectors and regulatory pathways.

Xiong, Liming; Zhu, Jian-Kang

2002-01-01

202

Detection of Eutectic Solidification during Freezing of Electrolyte Solutions by Electric Impedance Measuremen  

NASA Astrophysics Data System (ADS)

A feasibility study was carried out to develop a technique for detecting the occurrence of eutectic solidification of electrolyte solutions, which is a potential cause of cellular damage during freezing of cells and tissues. The electric impedance of a sodium chloride or a potassium chloride aqueous solution between two parallel electrodes was measured at subzero temperatures as a function of the frequency ranged from 1 to 105 Hz. The impedance increased abruptly with decreasing temperature near the eutectic point, suggesting the possible detection of eutectic solidification. Some extent of supercooling was observed before the eutectic solidification, while the impedance drop agreed well with the eutectic temperature during thawing.

Yoshida, Keisuke; Adachi, Kenji; Yoshimori, Takashi; Uchida, Satoru; Takamatsu, Hiroshi

203

Organic alloy systems suitable for the investigation of regular binary and ternary eutectic growth  

NASA Astrophysics Data System (ADS)

Transparent organic alloys showing a plastic crystal phase were investigated experimentally using differential scanning calorimetry and directional solidification with respect to find a suitable model system for regular ternary eutectic growth. The temperature, enthalpy and entropy of phase transitions have been determined for a number of pure substances. A distinction of substances with and without plastic crystal phases was made from their entropy of melting. Binary phase diagrams were determined for selected plastic crystal alloys with the aim to identify eutectic reactions. Examples for lamellar and rod-like eutectic solidification microstructures in binary systems are given. The system (D)Camphor Neopentylglycol Succinonitrile is identified as a system that exhibits, among others, univariant and a nonvariant eutectic reaction. The ternary eutectic alloy close to the nonvariant eutectic composition solidifies with a partially faceted solid liquid interface. However, by adding a small amount of Amino-Methyl-Propanediol (AMPD), the temperature of the nonvariant eutectic reaction and of the solid state transformation from plastic to crystalline state are shifted such, that regular eutectic growth with three distinct nonfaceted phases is observed in univariant eutectic reaction for the first time. The ternary phase diagram and examples for eutectic microstructures in the ternary and the quaternary eutectic alloy are given.

Sturz, L.; Witusiewicz, V. T.; Hecht, U.; Rex, S.

2004-09-01

204

Eutectic nucleation and growth in hypoeutectic Al-Si alloys at different strontium levels  

NASA Astrophysics Data System (ADS)

The effects of different levels of strontium on nucleation and growth of the eutectic in a commercial hypoeutectic Al-Si foundry alloy have been investigated by optical microscopy and electron backscattering diffraction (EBSD) mapping by scanning electron microscopy (SEM). The microstructural evolution of each specimen during solidification was studied by a quenching technique at different temperatures and Sr contents. By comparing the orientation of the aluminum in the eutectic to that of the surrounding primary aluminum dendrites by EBSD, the eutectic formation mechanism could be determined. The results of these studies show that the eutectic nucleation mode, and subsequent growth mode, is strongly dependent on Sr level. Three distinctly different eutectic growth modes were found, in isolation or sometimes together, but different for each Sr content. At very low Sr contents, the eutectic nucleated and grew from the primary phase. Increasing the Sr level to between 70 and 110 ppm resulted in nucleation of independent eutectic grains with no relation to the primary dendrites. At a Sr level of 500 ppm, the eutectic again nucleated on and grew from the primary phase while a well-modified eutectic structure was still present. A slight dependency of eutectic growth radially from the mold wall opposite the thermal gradient was observed in all specimens in the early stages of eutectic solidification.

Dahle, A. K.; Nogita, K.; McDonald, S. D.; Zindel, J. W.; Hogan, L. M.

2001-04-01

205

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

NASA Astrophysics Data System (ADS)

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.

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

2006-12-01

206

Microstructural development of eutectic Bi-Sn and eutectic In-Sn during high temperature deformation  

SciTech Connect

Eutectic Bi-Sn and In-Sn solder joints were subjected to high temperature deformation in shear in order to determine whether microstructural instabilities are generated during testing. Dynamic recrystallization had previously been observed in Sn-Pb solder joints during creep and fatigue in shear. The current study shows that Bi-Sn can recrystallize during deformation in creep or at constant strain rate, whereas no microstructural changes are observed in In-Sn. Recrystallization of Bi-Sn is concentrated in a narrow band along the length of the sample, parallel to the direction of shear strain, similar to behavior in Sn-Pb. The recrystallization appears to proceed by migration of interphase boundaries rather than by a nucleation and growth mechanism. A minimum total strain is required to induce obvious recrystallization in Bi-Sn, independent of applied stress or strain rate. This value of strain is much higher than the strain at initiation of tertiary creep or at the maximum shear stress. Onset of tertiary creep and strain softening occur as a result of nonuniform deformation in the samples that is independent of the microstructural instabilities. The creep behavior of In-Sn is relatively straightforward, with a single creep mechanism operating at all temperatures tested. 36 refs., 13 figs.

Goldstein, J.L.F.; Morris, J.W. Jr. (Lawrence Berkeley Lab., CA (United States) Univ. of California, Berkeley, CA (United States))

1994-05-01

207

CONTROLLED POTENTIAL COULOMETRIC AND POLAROGRAPHIC INVESTIGATIONS OF METALLIC IONS IN FUSED SALTS  

Microsoft Academic Search

Two types of platinum(II)--platinum(O) reference electrodes used in ; fused lithium chloride-potassium chloride eutectic were compared and tested with ; respect to their stability with repeated use. One type was completely enclosed ; in a borosilicate glass tube, the glass serving as a salt bridge to the melt, ; whereas the other contained a small asbestos fiber sealed into the

Caton; R. D. Jr

1963-01-01

208

Separation of Some Post-Transition Metal Ions by Thin-Layer Chromatography in Molten Salts  

Microsoft Academic Search

A method is described for the use of molten salts as an eluent for thin-layer chromatography of inorganic ions. The separation of some post-transition metal ions can be successfully accomplished through the use of alkali metal nitrate eutectic melts. The mechanism of separation appears to be one of cation exchange with the silica gel used as the adsorbent. By appropriate

Steven Abbe; Leonard F. Druding

1969-01-01

209

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

Microsoft Academic Search

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.

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

2003-01-01

210

Corrosion of Materials in Molten Alkali Carbonate Salt at 900 Degrees C.  

National Technical Information Service (NTIS)

This work was done to assess the compatibility of selected ceramics and alloys with ternary eutectic lithium-sodium-potassium carbonate at 900 deg C. This salt has been chosen for use in pilot-scale studies of the Direct Absorption Receiver, which will be...

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

1985-01-01

211

Hydride-containing molten salts and their technology implications  

Microsoft Academic Search

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

Bor Y. Liaw

1993-01-01

212

Molten salt EMF cell measurements on UGa alloys  

Microsoft Academic Search

The Gibbs free energies of formation of UGa3, UGa2 and U2Ga3 were determined by using high temperature molten salt galvanic cell measurements. Three cells were assembled and EMFs were measured. The typical cell is as follows: U(s)\\/\\/UCl3inLiClKCl(eutectic)(l)\\/\\/UGa(twophasealloy), where pure uranium is used as one of the electrodes and the other electrode is a two phase UGa alloy. The two phase

B Prabhakara Reddy; R Kandan; K Nagarajan; P. R Vasudeva Rao

2001-01-01

213

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

Microsoft Academic Search

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

Takatoshi Hijikata; Tadafumi Koyama

2010-01-01

214

Nickel-plating for active metal dissolution resistance in molten fluoride salts  

Microsoft Academic Search

Ni electroplating of Incoloy-800H was investigated with the goal of mitigating Cr dissolution from this alloy into molten 46.5%LiF11.5%NaF42%KF eutectic salt, commonly referred to as FLiNaK. Tests were conducted in graphite crucibles at a molten salt temperature of 850C. The crucible material graphite accelerates the corrosion process due to the large activity difference between the graphite and the alloy. For

Luke Olson; Kumar Sridharan; Mark Anderson; Todd Allen

2011-01-01

215

Synthesis of LiMn 2 O 4 by molten salt technique  

Microsoft Academic Search

Lithium manganese oxide powders have been successfully prepared by a molten salt synthesis using eutectic mixture of LiCl\\u000a and MnO2 salt at 900C. The synthesis was performed in open atmosphere. The crystalline powders were characterized for their phase\\u000a identification using X-ray diffraction analysis. The physicochemical properties of the lithium manganese oxide powders are\\u000a investigated by thermal analysis (thermo gravimetric analysis\\/

M. Helan; L. John Berchmans; A. Zahir Hussain

2010-01-01

216

ENGINEERING EXPERIENCE AT BROOKHAVEN NATIONAL LABORATORY IN HANDLING FUSED CHLORIDE SALTS  

Microsoft Academic Search

Two fused chloride salt eutectics, binary LiCl-KCl and ternary NaCl- KCl-;\\u000a MgCl, were used in fuel processing studies as part of the Liquid Metal ;\\u000a Fuel Reactor research and development program. Results of engineering work done ;\\u000a at Brookhaven since 1950 are summarized. It was demonstrated that fused chloride ;\\u000a salt technology is sufficiently developed so that loops and other

C. J. Raseman; H. Susskind; G. Farber; W. E. McNulty; F. J. Salzano

1960-01-01

217

Development of a supported molten-salt Wacker catalyst for the oxidation of ethylene to acetaldehyde  

Microsoft Academic Search

A modified supported molten-salt Wacker catalyst involving palladium chloride\\/copper chloride is developed by replacing the conventional aqueous reaction medium (HO + HCl) with a eutectic melt of cuprous chloride and potassium chloride and supporting it on a porous support. Experimental studies for the oxidation of ethylene to acetaldhyde over the supported molten-salt catalyst (SMSC) show the kinetics to be similar

V. Rao; R. Datta

1988-01-01

218

Synthesis of oxide perovskite solid solutions using the molten salt method  

Microsoft Academic Search

The molten salt method has in the past been employed to synthesize a large number of compounds at low temperatures. In this work we report the formation of solid solutions of BaTiO3 - SrTiO3 and BaZrO3 - SrZrO3 using a molten salt eutectic of NaOH- KOH as a solvent. Alkaline earth carbonates and titanium oxide were used as precursors for

Srikanth Gopalan; Karun Mehta; Anil V. Virkar

1996-01-01

219

High temperature molten salt storage  

NASA Astrophysics Data System (ADS)

The design of a high-temperature molten salt thermal energy storage (TES) concept, including some materials testing, was developed by Rockwell International's Rocketdyne Division (RD), under contract to SERI, and is described in this document. The main features of the concept are a conical hot tank with a liner and internal insulation that allows unrestricted relative thermal expansion and the use of cathodic protection (impressed voltage) to inhibit corrosion. The RD design uses two tanks and ternary eutectic lithium-sodium-potassium carbonates for sensible heat storage. The tanks were sized for 6 h of storage at a discharge rate of 300 MW, giving 1800 MWh total usable thermal storage capacity. The molten carbonate storage medium is cycled between 425 and 900C. From the design study, no definitive statement can be made as to the cost-effectiveness of cathodic protection. Several anode design issues need to be resolved before cathodic protection can significantly reduce corrosion where the liner comes in contact with molten salts. However, where the tank is exposed to salt vapor, the large corrosion allowance required for the liner without cathodic protection results in a much thicker liner wall and shorter liner life than originally perceived, which affects system costs significantly.

Ives, J.; Newcomb, J. C.; Pard, A. G.

1985-10-01

220

Salts & Solubility  

NSDL National Science Digital Library

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.

Adams, Wendy; Koch, Linda; Lemaster, Ron; Loeblein, Trish; Perkins, Kathy; Harlow, Danielle

2011-01-01

221

Leadlithium eutectic material database for nuclear fusion technology  

Microsoft Academic Search

Fully validated material databases are needed for coherent technological developments in any R&D field. For nuclear fusion technology (NFT), within a near-term perspective of qualification and licensing of nuclear components and systems, this goal is both compulsory and urgent. This mandatory requirement applies for the particular case of the PbLi eutectic database as fusion reactor material. Pb16Li is today a

E. Mas de les Valls; L. A. Sedano; L. Batet; I. Ricapito; A. Aiello; O. Gastaldi; F. Gabriel

2008-01-01

222

Dry sliding wear of eutectic AlSi  

Microsoft Academic Search

The wear of as-cast eutectic AlSi was studied using pin-on-disk tribotests in two different environments, air and dry argon.\\u000a The counterface in all tests was yttria-stabilized zirconia. It was found that wear of the AlSi was reduced by about 60%\\u000a by the removal of oxygen from the test environment. The zirconia counterfaces showed measurable wear after tests performed\\u000a in air,

I. BakerY; Y. Sun; F. E. Kennedy; P. R. Munroe

2010-01-01

223

Creep behavior of Ni-Cr lamellar eutectic alloy  

Microsoft Academic Search

The structural changes that occur during creep deformation at 625 and 760C, with creep and creep rupture data of a directionally\\u000a solidified Ni-Cr lamellar eutectic alloy are presented and discussed. It is shown that the characteristic features of stage\\u000a I deformation are the formation of dislocation tangles in the nickel-rich phase and shearing of the cellular structure; these\\u000a features are

Ram Kossowsky

1970-01-01

224

Cavitational Failure Phenomenon in Pb-Sn Eutectic Solders  

Microsoft Academic Search

This report concerns mechanisms on the formation of r-type crack (or cavitation) associated with grain boundary sliding in Pb-Sn eutectic solders used for microelectronic applications. The experimental works indicate that cavitation takes place in a specimen deformed in a tensile test at a relatively low strain rate of 710-6\\/ s and in specimens fatigued at 0.1% to 0.2% strain range

Seong-Min Lee

1995-01-01

225

Microstructure evolution of eutectic SnAg solder joints  

Microsoft Academic Search

Laser and infrared reflow soldering methods were used to make Sn-Ag eutectic solder joints for surface-mount components on\\u000a printed wiring boards. The microstructures of the joints were evaluated and related to process parameters. Aging tests were\\u000a conducted on these joints for times up to 300 days and at temperature up to 190C. The evolution of microstructure during\\u000a aging was examined.

Wenge Yang; Robert W. Messler; Lawrence E. Felton

1994-01-01

226

Microstructure evolution of eutectic SnAg solder joints  

Microsoft Academic Search

Laser and infrared reflow soldering methods were used to make Sn-Ag eutectic solder joints for surface-mount components on printed wiring boards. The microstructures of the joints were evaluated and related to process parameters. Aging tests were conducted on these joints for times up to 300 days and at temperature up to 190C. The evolution of microstructure during aging was examined.

Wenge Yang; Robert W. Messler; Lawrence E. Felton

1994-01-01

227

Al Cu eutectic: an experimental study of its melting properties  

Microsoft Academic Search

Equilibrium melting curves of nominally 99.9999% pure Al-Cu eutectic samples were realized. The end of the linear portion of the melting curves, the run-off point, was found to be (548.1608 0.0007) C. The uncertainty is one standard deviation of the twelve measured values. Some of the samples were then doped with Si, Fe and Ag. These impurities shifted their

J. Ancsin

2007-01-01

228

Eutectic epsilon-near-zero metamaterial terahertz waveguides.  

PubMed

We present and analyze the unique phenomena of enhanced THz transmission through a subwavelength LiF dielectric rod lattice embedded in an epsilon-near-zero KCl host. Our experimental results in combination with theoretical calculations show that subwavelength waveguiding of terahertz radiation is achieved within an alkali-halide eutectic metamaterial as result of the coupling of Mie-resonance modes arising in the dielectric lattice. PMID:23546270

Massaouti, M; Basharin, A A; Kafesaki, M; Acosta, M F; Merino, R I; Orera, V M; Economou, E N; Soukoulis, C M; Tzortzakis, S

2013-04-01

229

Ce-doped Al2O3-YAG eutectic and its application for white LEDs  

NASA Astrophysics Data System (ADS)

Ce-doped Al2O3-YAG (Y3Al5O12, yttrium aluminum garnet) eutectic, a resin-free phosphor for white light emitting diodes (WLEDs), was successfully grown by the Czochralski method. X-ray diffraction and scanning electron microscopy show that this material has a typical eutectic structure of interpenetrating sapphire and garnet phases, as well as lamellar spacing in the order of tens of microns. The eutectic has a higher Ce3+ segregation coefficient than YAG single crystal. The photoluminescence properties of this eutectic were also investigated. Results show that it is characterized by a wide excitation band, and that the luminous efficiency of a eutectic-packaged LED is higher than that of a phosphor powder-packaged LED. The findings indicate that the Al2O3-YAG eutectic is a promising phosphor for WLED applications.

Sai, Qinglin; Zhao, Zhiwei; Xia, Changtai; Xu, Xiaodong; Wu, Feng; Di, Juqing; Wang, Lulu

2013-10-01

230

Nucleation behaviour and anomalous eutectic formation in highly undercooled Fe2O3La2O3 eutectic melts  

Microsoft Academic Search

Employing an aero-acoustic levitator, the Fe2O3-16.5 mol% La2O3 eutectic alloy was levitated, melted, undercooled and then solidified under a containerless condition when a continuous laser beam heating system was incorporated. By revealing the surface and cross-sectional microstructures, copious nucleation is confirmed to take place in the undercooled melts solidified by either an external seeding or spontaneous crystallization. The nucleation behaviour

Mingjun Li; Kosuke Nagashio; Kazuhiko Kuribayashi

2003-01-01

231

Salt Painting  

NSDL National Science Digital Library

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.

Omsi

2004-01-01

232

Encapsulation of vacuum sensors in a wafer level package using a gold-silicon eutectic  

Microsoft Academic Search

A vacuum package based on gold-silicon eutectic wafer bonding has been developed and evaluated using high sensitivity poly-Si Pirani vacuum sensors. Encapsulation of the devices was achieved by bonding a silicon cap wafer to a device wafer using a Au-Si eutectic solder at or above 390C in a vacuum bonder. The Au-Si eutectic solder encircled the devices, providing an airtight

Jay Mitchell; G. R. Lahiji; K. Najafi

2005-01-01

233

Transient and steady state creep response of ice I and magnesium sulfate hydrate eutectic aggregates  

Microsoft Academic Search

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

Christine McCarthy; Reid F. Cooper; David L. Goldsby; William B. Durham; Stephen H. Kirby

2011-01-01

234

Reliability of Eutectic Sn-Pb Solder Bumps and Flip Chip Assemblies  

Microsoft Academic Search

This paper presents an experimental study on the reliability of eutectic Sn-Pb (Sn63\\/Pb37) solder bumps and the reliability of eutectic Sn-Pb bumped flip chip (FC) assemblies mounted on an FR- 4 substrate. The growth kinetics of Sn-Ni intermetallic compound, Ni 3 Sn 4 , on eutectic Sn-Pb solder bumped chips with Ni(P)\\/Au metallization was investigated. The growth of Ni 3

Xingjia Huang; Christine Kallmayer; Rolf Aschenbrenner; W. Ricky Lee

235

Inhibition effect of sugar-based amphiphiles on eutectic formation in the freezing-thawing process of aqueous NaCl solution.  

PubMed

DSC and simultaneous XRD-DSC measurements were carried out to clarify the interaction among the ingredients in a ternary aqueous solution composed of NaCl, a sugar-based amphiphile or free sugar, and water. Two aspects of the inhibition of eutectic formation were suggested through the addition of the sugar amphiphile. One was the retention of the glass state of the eutectic phase, and the other was the trapping of NaCl hydrate into the sugar moiety of the amphiphilic aggregate. The difference between the free sugar and the amphiphilic one in terms of the trapping of NaCl hydrate was attributable to their dissimilarity in the dissolution state. The results indicated that the free sugars in water could interact with NaCl hydrate on the basis of their various hydroxyl groups. On the other hand, the sugar-based amphiphiles generated a self-assembly aggregate in the system, and interacted with NaCl hydrate by a salting-in effect with their sugar moiety in the freezing-thawing process. It was confirmed that the number of sugar units played an important role in trapping NaCl hydrate in the system. The effects of the structural isomerism in the sugars were slight with regard to the inhibition of eutectic formation. PMID:17391663

Ogawa, Shigesaburo; Osanai, Shuichi

2007-01-30

236

Time-resolved laser-induced fluorescence spectroscopy of Nd3+ in molten LiCl-KCl eutectic  

NASA Astrophysics Data System (ADS)

The characteristics of the laser-induced fluorescence of Nd3+ in LiCl-KCl eutectic in the wavelength region of 360-900 nm were investigated for information concerning the chemical speciation of Nd-chloride complexes. When pumped at either 355 or 532 nm, Nd3+ in molten salt emits visible and near-IR fluorescence. The fluorescence peaks at 750 nm (4F7/2 + 4S3/2 ? 4I9/2) and 810 nm (4F5/2 + 2H9/2 ? 4I9/2) were particularly prominent at temperatures above the melting point. The fluorescence decay of these transition lines showed a bi-exponential behaviour of the fluorescence lifetime. These results provide evidence that two different chemical species of Nd3+ coexist in this system.

Jung, E. C.; Bae, S.-E.; Park, Y. J.; Song, K.

2011-11-01

237

Measurements of the partial electronic conductivity in lithium chloride - potassium chloride molten salts  

SciTech Connect

The partial electronic conductivity of the lithium chloride-potassium chloride eutectic molten salt electrolyte has been studied as a function of lithium activity, temperature and melt composition using the Wagner asymmetric d-c polarization technique. Measurements were made over the temperature range 383-465/sup 0/C and at lithium activities extending from 1.95 X 10/sup -7/ to unity. The results confirmed the applicability of this technique to molten salt systems. The partial electronic conductivity was shown to be much greater than the partial hole conductivity over the range of lithium activities investigated, and was found to increase monotonically with temperature and lithium activity, but decreased on addition of excess LiCl to the eutectic composition. Approximate values of self-discharge currents for cells utilizing an ''Al/LiAl'' negative electrode and a LiCl-KCl molten salt electrolyte have been calculated.

Reynolds, G.J.; Huggins, R.A.; Lee, M.C.Y.

1983-05-01

238

Ionic liquids in biotransformations: from proof-of-concept to emerging deep-eutectic-solvents.  

PubMed

Ionic liquids (ILs) have been extensively assessed in biotransformations with different purposes, for example, non-conventional (co-)solvents, performance additives, coating agents for immobilizing/stabilizing enzymes, and IL-membrane-based processes. Fuelled by their premature labelling as 'green solvents', academic research has flourished. However, in recent years environmental aspects related to ILs have been strongly addressed, stating that many ILs commonly used cannot be regarded as 'green derivatives'. Likewise, ILs costs are still a barrier for practical uses. Attempting to combine sustainability with the promising added-values of ILs, the third generation of ILs is currently under development. Likewise, deep-eutectic-solvents (DESs) appear in the horizon as an attractive and cost-effective option for using ionic solvents in biotransformations. DESs are often produced by gently warming and stirring two (bio-based and cheap) salts (e.g. choline chloride and urea). First successful uses of DES in biotransformations were reported recently. It may be expected that knowledge accumulated in (second generation) ILs and biotransformations could be turned into real applications by using these DESs, and third generation ILs, in the coming years. PMID:21112808

Domnguez de Mara, Pablo; Maugeri, Zaira

2010-11-26

239

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

PubMed

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

Menor-Salvn, Csar; Marn-Yaseli, Margarita R

2012-06-01

240

Influence of Phosphorus on the Nucleation of Eutectic Silicon in Al-Si Alloys  

NASA Astrophysics Data System (ADS)

The role of phosphorus (P) in the heterogeneous nucleation of eutectic silicon (Si) and the evolution of eutectic grains in hypoeutectic aluminum-silicon alloys were investigated. Systematic additions of P in the range of 0.5 to 20 ppm to Al-7 wt pct Si alloys of different purities have shown that the morphology of the eutectic Si changes from a fine plate- to a coarse flake-like structure. The growth of eutectic grains was investigated by interrupting the eutectic reaction by quenching experiments. Moreover, the macroscopic growth mode of the eutectic grains was characterized by electron backscatter diffraction. An increase in P concentration from 2 to 3 ppm resulted in a transition of the macroscopic growth mode of the Al-Si eutectic in high purity alloys from growth with a planar front with a strong dependence of the thermal gradient, to nucleation in the vicinity of the primary Al dendrites and subsequent growth of distinct eutectic grains. It is suggested that AlP particles are the key impurities acting as potential nucleation sites for eutectic Si. This is further substantiated as with increasing P concentration nucleation and growth of the Al-Si occurred at higher temperatures close the equilibrium Al-Si eutectic solidification temperature at 850 K (577 C). In addition, the recalescence undercooling ?T R,eu was reduced from 4.5 K (0.5 ppm P) to 1.5 K (20 ppm P) in high purity alloys. This was accompanied by a drastic increase of the nucleation rate of the eutectic grains.

Ludwig, Thomas Hartmut; Schaffer, Paul Louis; Arnberg, Lars

2013-08-01

241

Molten salts as promising catalysts for oxidation of diesel soot: importance of experimental conditions in testing procedures  

Microsoft Academic Search

The catalytic activity for soot oxidation of three eutectic salt mixtures based on oxides or sulphates of molybdenum, vanadium, and cesium, was studied and compared with the activity of catalysts reported in literature. It is shown that some of these mixtures have a high activity above their melting point of about 625K. The activity of these catalysts can be up

S. J Jelles; B. A. A. L van Setten; M Makkee; J. A Moulijn

1999-01-01

242

Low-cost central receiver solar power plant using molten salt as a heat transfer and storage medium  

Microsoft Academic Search

The paper proposes an alternative approach to solar thermal power plants to reduce the electricity cost relative to the first generation water\\/steam systems. The cost reduction is achieved by generating a 950 F 2400 psig steam by pumping an eutectic salt mixture of sodium nitrate and potassium nitrate as the heat transfer and storage medium to the steam generator and\\/or

T. R. Tracey

1979-01-01

243

A new flow calorimeter using a eutectic molten salt as the temperature control medium  

Microsoft Academic Search

A new isothermal flow calorimeter for measuring heats of mixing of two fluid streams at high temperatures and pressures is described. The main advantages of the new calorimeter over earlier ones are simplification of the design making it easier to maintain the equipment, reduction of the temperature gradients so that baseline corrections are minimized, and ability to make reliable measurements

Saowarux Fuangswasdi; John L Oscarson; Li Zhou; Reed M Izatt

2001-01-01

244

Eutectic salt promoted lithium zirconate: Novel high temperature sorbent for CO 2 capture  

Microsoft Academic Search

High performance, cost efficient CO2 capture technologies are desired to significantly reduce CO2 emissions from large stationary sources, i.e., fossil fuel-fired power stations. Advanced processes based on solid regenerable sorbents that efficiently absorb CO2 and release it in concentrated form can be less toxic, less corrosive and economically attractive relative to commercially existing solvent-based technologies. In this study, a number

Daniel J. Fauth; Elizabeth A. Frommell; James S. Hoffman; Randall P. Reasbeck; Henry W. Pennline

2005-01-01

245

Minimization of Eutectic Salt Waste from Pyroprocessing by Oxidative Precipitation of Lanthanides  

Microsoft Academic Search

A lab-scale lanthanide precipitation apparatus, which has a 4 kg\\/batch size, was installed and tested. By using this lab-scale apparatus, cooxidative precipitation experiments of lanthanides were carried out. As lanthanides, 8 rare-earth elements (Y, La, Ce, Pr, Nd, Sm, Eu, and Gd) were used. By a reaction with oxygen, La, Pr, Nd, Sm, Eu, and Gd were converted to their

Yung-Zun CHO; Gil-Ho PARK; Hee-Chul YANG; Dae-Seok HAN; Han-Soo LEE; In-Tae KIM

2009-01-01

246

Operating experience with off-peak brick furnaces, pressurized water systems, and eutectic salt systems  

Microsoft Academic Search

This paper reports on the efforts of the Load Management Branch of the TVA to investigate the performance of thermal storage devices in both the residential and commercial-industrial sectors. Tests are being conducted on the performance of cool storage devices as well as heat storage systems in the commercial industrial area. In the residential sector, demonstrations include both time-of-day and

E. L. Colston; B. G. Beames; A. B. Dahmus

1983-01-01

247

Composition gradients in electrolyzed LiCl-KCl eutectic melts  

NASA Astrophysics Data System (ADS)

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.

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

1983-12-01

248

Pattern Formation and Growth Kinetics in Eutectic Systems  

SciTech Connect

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.

Jing Teng

2007-12-01

249

Cavitational Failure Phenomenon in Pb-Sn Eutectic Solders  

NASA Astrophysics Data System (ADS)

This report concerns mechanisms on the formation of r-type crack (or cavitation) associated with grain boundary sliding in Pb-Sn eutectic solders used for microelectronic applications. The experimental works indicate that cavitation takes place in a specimen deformed in a tensile test at a relatively low strain rate of 710-6/ s and in specimens fatigued at 0.1% to 0.2% strain range and a frequency of 1.6710-2/ s. Based on these phenomenological observations, it is discussed that the presence of cavities requires large sliding displacements combined with a high stresses.

Lee, Seong-Min

1995-11-01

250

Synthesis of LiSm 0.01Mn 1.99O 4 by molten salt technique  

Microsoft Academic Search

Samarium substituted lithium manganese oxide powders were successfully prepared by molten-salt synthesis (MSS) using eutectic mixture of LiCl, SmCl36H2O and MnO2 salt at 700 C. The synthesis was carried out in open atmosphere. The crystalline powders were characterized for their phase identification using X-ray diffraction (XRD) analysis. The physico-chemical properties of the samarium substituted lithium manganese oxide powders were investigated

M. Helan; L. John Berchmans

2010-01-01

251

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

SciTech Connect

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

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

252

Directionally Solidified Pseudo-Binary Eutectics of Ni-Cr-(Hf, Zr).  

National Technical Information Service (NTIS)

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 di...

Y. G. Kim R. L. Ashbrook

1975-01-01

253

Oxygen Partial Pressure: A Key to Alloying and Discovery in Metal Oxide--Metal Eutectic Systems.  

National Technical Information Service (NTIS)

Control of oxygen partial pressure is essential in the directional solidification of oxide--metal eutectic composites by techniques involving gas-solid and gas-liquid interactions. The existence of end components in the eutectic composite is Po sub 2 sens...

J. D. Holder G. W. Clark B. F. Oliver

1978-01-01

254

Characteristics of the binary faceted eutectic: benzoic acid - salicylic acid system  

Microsoft Academic Search

The consistent symmetry relations computed from the heterogeneous nucleation data of the non-ideal benzoic acid - salicylic acid eutectic system verifies the validity of nucleation theory. The kinetics of crystal growth from the molten state of the system follows the dislocation mechanism. Anomalous behaviour of both viscosity and activation energy for the eutectic melt confirms the essence of specific interactions

B. L. Sharma; S. Tandon; S. Gupta

2009-01-01

255

Thermodynamic and lamella models relationship for the eutectic system benzoic acid cinnamic acid  

Microsoft Academic Search

The present investigation reveals the relationship between excess thermodynamic functions and the growth habits of the eutectic phases from the melt by continuous melt-growth technique. Excess thermodynamic functions computed for different compositions of the benzoic acid - cinnamic acid eutectic system have been found consistent with the criteria of spontaneity and Planck formulation, and their reliability has been ascertained by

B. L. Sharma; R. Jamwal; R. Kant

2004-01-01

256

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

NASA Astrophysics Data System (ADS)

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.

Misra, Ajay K.

1988-04-01

257

Molten salt synthesis and thermoelectric properties of Ca 2Co 2O 5  

Microsoft Academic Search

A molten salt method was applied to synthesize Ca2Co2O5 powder by using Co3O4 and CaCO3 as raw materials and CaCO3CaCl2 as eutectic salt. The formation process and molten salt mechanism of Ca2Co2O5 were investigated by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that sheet-like particles can be obtained at 963K. Moreover, the electrical conductivity and

J. Pei; G. Chen; X. Li; Y. X. Li; N. Zhou

2009-01-01

258

Hydride-containing molten salts and their technology implications  

NASA Astrophysics Data System (ADS)

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.

Liaw, Bor Y.

1993-03-01

259

Anthracene + Pyrene Solid Mixtures: Eutectic and Azeotropic Character  

PubMed Central

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.

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

2010-01-01

260

Anthracene + Pyrene Solid Mixtures: Eutectic and Azeotropic Character.  

PubMed

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 x(1) = 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 x(1) < 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 x(1) of 0.03 and 0.14. Additionally, mixtures at x(1) = 0.99 sublime at the vapor pressure of pure anthracene, suggesting that anthracene behavior is not significantly influenced by x(2) = 0.01 in the crystal structure. PMID:21116474

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

2010-09-01

261

Salt-hydrate thermal-energy-storage system for space heating and air conditioning  

NASA Astrophysics Data System (ADS)

Latent heat storage equipment using three different salts was developed. The salts are: sodium sulfate pentahydrate which melts at 460 C, magnesium chloride hexahydrate which melts at 1150 C, and a eutectic combination of seven different materials which melts at 70 C. Stirring pumps, tanks, and tubing materials, and field filling of the salts into their tanks are developed. good performance for the tank/heat exchangers with all three salts is reported. Both the 1150 C and 460 C salts are almost equivalent in volume storage to water/ice. The 79.0 C salt, however, begins at about 56% of the BTU's per cubic foot of water/ice and declines due to separation to 40% after repeated cycling.

MacCracken, C. D.; Armstrong, J. M.; MacCracken, M. M.; Silvetti, B. M.

1980-07-01

262

Removal of alkaline-earth elements by a carbonate precipitation in a chloride molten salt  

SciTech Connect

Separation of some alkaline-earth chlorides (Sr, Ba) was investigated by using carbonate injection method in LiCl-KCl eutectic and LiCl molten salts. The effects of the injected molar ratio of carbonate([K{sub 2}(or Li{sub 2})CO{sub 3}/Sr(or Ba)Cl{sub 2}]) and the temperature(450-750 deg.) on the conversion ratio of the Sr or Ba carbonate were determined. In addition, the form of the Sr and Ba carbonate resulting from the carbonation reaction with carbonates was identified via XRD and SEM-EDS analysis. In these experiments, the carbonate injection method can remove Sr and Ba chlorides effectively over 99% in both LiCl-KCl eutectic and LiCl molten salt conditions. When Sr and Ba were co-presented in the eutectic molten salt, they were carbonated in a form of Ba{sub 0.5}Sr{sub 0.3}CO{sub 3}. And when Sr was present in LiCl molten salt, it was carbonated in the form of SrCO{sub 3}. Carbonation ratio increased with a decreasing temperature and it was more favorable in the case of a K{sub 2}CO{sub 3} injection than that of Li{sub 2}CO{sub 3}. Based on this experiment, it is postulated that carbonate precipitation method has the potential for removing alkali-earth chlorides from LiCl-KCl eutectic and LiCl molten salts. (authors)

Yung-Zun Cho; In-Tae Kim; Hee-Chui Yang; Hee-Chui Eun; Hwan-Seo Park; Eung-Ho Kim [Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong-gu, Daejeon, 305-353 (Korea, Republic of)

2007-07-01

263

Chlorate salts and solutions on Mars  

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

264

Microstructure and Physical Properties of Sulfate Hydrate/Ice Eutectic Aggregates in the Binary System Sodium-Sulfate/Water at Planetary Conditions  

NASA Astrophysics Data System (ADS)

Reflectance spectra data from Mars Odyssey, Galileo and potentially from Cassini suggest the presence of hydrated salts on numerous satellites in environments such as evaporate beds or combined with water ice. Improved mission data on these occurrences indicate that grain structures and properties of such materials merit a closer look using laboratory methods. Here we report the synthesis of a two-phase aggregate of sodium sulfate hydrate and water ice made by eutectic solidification from solution, characterization of its microstructure using cryogenic SEM, and comparison of its physical properties to those of its end-member components. Samples are crystallized from solution using a precision cryobath and seeded growth. The reaction is a "simple" one meaning that there is no solid solution formation in either of the two solid phases. The eutectic composition we studied for the sodium sulfate hydrate is 4wt% Na2SO4, which corresponds to about .06 volume fraction of Na2SO4?10H2O, mirabilite, and .94 ice I. The eutectic microstructure observed with this volume fraction, which is termed "broken lamellar", consists of fairly uniform blade-like mirabilite grains arranged in roughly parallel columns within a water ice matrix. The blades and matrix material form a lamella that alternates with lamellae of pure ice. Energy dispersive spectroscopy of these eutectic mixtures confirms the presence of the two crystalline phases. Also, we find that lamellar spacing decreases with increasing growth rate. Constant-strain-rate tests in compression are carried out in the cryogenic gas deformation apparatus at LLNL in a pressure-temperature range appropriate to the icy satellites. We report the rheology of the two-phase aggregate and compare it to the strength properties of pure water ice and pure mirabilite. With the aid of numerous studies on similar structures in the literature on metals, we analyze the deformation mechanics from the perspective of defect and crack propagation between the two phases in the eutectic structure. This ongoing investigation is the first of several planned experimental studies of sulfate-hydrate binaries with ice I that are likely to be important in the icy satellites.

McCarthy, C. M.; Kirby, S.; Durham, W.; Stern, L.

2004-12-01

265

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.

266

Electrochemistry of nitrogen and nitrides in molten salts  

NASA Astrophysics Data System (ADS)

Electrochemical behavior of nitrogen and nitrides in a molten LiCl KCl Li3N system has been investigated from thermodynamic and kinetic point of view. Nitride ions are anodically oxidized to form nitrogen gas almost quantitatively on a nickel electrode according to the following reaction: N=12N2+3e. This is a reversible one-step three-electron reaction governed by a simple diffusion-controlled charge transfer process. The diffusion coefficient of nitride ion is estimated to be about 1.8 10-5 cm2 s-1 at 723 K. On the other hand, nitrogen gas is cathodically reduced almost quantitatively to form nitride ions, the reaction of which is expressed as 12N2+3e=N. The standard electrode potential of an N2/N3- couple, EN2/N0, at 723 K was found to be 0.382 V vs. Li+/Li. Potential-pN3- diagrams were constructed using EN2/N0 together with thermochemical data for elements relevant to the electrochemical reprocessing of nitride fuels. The obtained results also enable us to propose new processes such as the electrochemical formation of functional nitride films and the electrochemical synthesis of ammonia gas under ambient pressure.

Ito, Yasuhiko; Goto, Takuya

2005-09-01

267

Dynamic solidification mechanism of ternary Ag-Cu-Ge eutectic alloy under ultrasonic condition  

NASA Astrophysics Data System (ADS)

The dynamic solidification of ternary Ag38.5Cu33.4Ge28.1 eutectic alloy within a 35 kHz ultrasonic field is investigated and compared with both its equilibrium solidification by DSC method and its rapid solidification in drop tube. The volume fractions of the primary (Ge) phase and pseudobinary (Ag+ ? 2) eutectic solidified within ultrasonic field are larger than those formed under equilibrium state, whereas that of ternary (Ag+ ? 2+Ge) eutectic exhibits the reverse trend. During rapid solidification, the liquid alloy droplet directly solidifies into ternary (Ag+ ? 2+Ge) eutectic if its diameter is smaller than 350 ?m. The ultrasound stimulates the nucleation of alloy melt and prevents the bulk undercooling. With the increase of sound intensity, the primary (Ge) phase transfers from faceted dendrites to nonfaceted blocks with blunt edges, and its grain size is remarkably reduced. Both pseudobinary (Ag+ ? 2) and ternary (Ag+ ? 2+Ge) eutectics experience a morphological transition from regular to anomalous structures. This indicates that their cooperative growth mode is replaced by independent growth of eutectic phases under the combined effects of cavitation and acoustic streaming. The ultrasound also shows a prominent coarsening effect to the pseudobinary (Ag+ ? 2) and ternary (Ag+ ? 2 +Ge) eutectics.

Zhai, Wei; Hong, ZhenYu; Mei, CeXiang; Wang, WeiLi; Wei, BingBo

2013-02-01

268

Effect of Alloying Elements on the Electrification-Fusion Phenomenon in Sn-Based Eutectic Alloys  

NASA Astrophysics Data System (ADS)

The effect of alloying elements on the electrification-fusion phenomenon in Sn-based eutectic alloys (Sn-9Zn and Sn-37Pb) under alternating current was investigated in this study. Experimental results showed that the critical fusion current densities (CFCD) of Sn-based alloys were closely related to both the conductivity of the individual phase and the eutectic temperature. While the electrical current density value required to trigger microstructural evolution for the Sn-9Zn alloy was larger than the CFCD of pure Sn (1399 A/cm2), that for the Sn-37Pb alloy was not. Through in situ examination of the microstructural evolution during electrification-fusion tests, the initial liquation site emerged from individual Sn-based eutectic phase (i.e., the Sn/Zn eutectic phase or Sn/Pb eutectic phase); The liquation regions in the Sn/Zn eutectic phase and ?-Sn phase of the Sn-9Zn alloy were not concentrated over the observation area. The liquation regions in the Sn/Pb eutectic phase and ?-Sn phase of the Sn-37Pb alloy were extensively distributed over the observation area. According to the fusion distributed density at the observation area, the Sn-9Zn alloy has great potential to replace the Sn-37Pb alloy in future electrification applications.

Lan, Gong-An; Lui, Truan-Sheng; Chen, Li-Hui

2013-02-01

269

Role of Sulfur on the Transition from Graphite to Cementite Eutectic in Cast Iron  

NASA Astrophysics Data System (ADS)

In the current study, an analytic solution is considered to explain the influence of sulfur on the transition from graphite to cementite eutectic in cast iron. The outcome from the current study indicates that this transition can be related to (a) the graphite nucleation potential (directly characterized by the cell count and indirectly by the nucleation coefficients; (b) the eutectic graphite growth rate coefficient; (c) the temperature range between the equilibrium temperature for graphite eutectic and the formation temperature for cementite eutectic; and (d) the liquid volume fraction, after pre-eutectic austenite solidification. In addition, the absolute and the relative chilling tendencies, as well as critical cooling rates including the chill width of the cast iron can be predicted from the current study. The analytic model was experimentally verified for castings with various sulfur contents. It is found that the main role of sulfur on the transition from graphite to cementite eutectic is through its effect on lowering the growth coefficient, and hence, the graphite eutectic growth rate. In addition, it is found that with the increasing sulfur content, the critical cooling rate is significantly reduced, thus increasing the absolute and the relative chilling tendency values, including the chill width.

Fra?, Edward; Grny, Marcin; Lopez, Hugo F.; Kawalec, Magdalena

2013-06-01

270

Critical temperature of the lead bismuth eutectic (LBE) alloy  

NASA Astrophysics Data System (ADS)

Liquid metals such as Bi and Pb and Pb Bi eutectic alloy are serious contenders for use as coolant in LMFBRs in lieu of sodium due to a number of attractive characteristics (high density, low moderation, low neutron absorption and activation, high boiling point and poor interaction with water and air, etc.). Analysis of hypothetical accidents is of relevance to predict the catastrophe involving loss of coolant accident (LOCA) in LMFBRs. One key parameter to take into account is the critical temperature data of the liquid metals for reactor safety analysis. This communication reports the application of a theoretical model called internal pressure approach to predict the critical temperature (Tc) of the LBE alloy for the first time.

Azad, Abdul-Majeed

2005-05-01

271

Powder eutectic coating with Al3Ti for steels  

NASA Astrophysics Data System (ADS)

Plates and round bars made of a pure iron or a carbon steel (JIS-S45C) have successfully been coated with Al3Ti powder by the powder eutectic coating method. The coated layers are found to show graded microstructures, where the concentrations of Fe, Al, and Ti change gradually from the surface toward the inside of a specimen. The microstructure of the coated layer consists of Al3Ti, ?3 (Al22Fe3Ti8), ?2 (Al2FeTi), and B2 (FeAl). When the coated specimens were subjected to heat-cycling tests between 293 and 973 K, they showed no cracking, no peeling, little oxidation, and no significant changes in microstructure.

Kafuku, H.; Tomota, Y.; Suzuki, T.; Isaka, M.

2002-10-01

272

Oxygen concentration measurement in liquid lead-bismuth eutectic  

SciTech Connect

Liquid lead-bismuth (Pb-Bi) eutectic (LBE) may see extensive use as a coolant fluid, and perhaps also as a spallation target, in next generation nuclear energy systems. While it is not as reactive as alkali metal liquids, it does present a long term corrosion problem with some materials, notably stainless steels. Mitigation of the corrosion problem may be achieved by producing and maintaining a protective oxide on exposed surfaces, through control of the concentration of dissolved oxygen in the LBE. We have developed an oxygen sensor based on available zirconia-based solid electrolytes used in the automotive industry, which represents a relatively inexpensive source of reproducible and reliable components. We will present the design considerations and characteristics of our sensor unit, and describe its use in the LBE test loop at Los Alamos for measurement and control of dissolved oxygen concentration.

Darling, T. W. (Timothy W.); Li, N. (Ning)

2001-01-01

273

Microstructure evolution of eutectic Sn-Ag solder joints  

NASA Astrophysics Data System (ADS)

Laser and infrared reflow soldering methods were used to make Sn-Ag eutectic solder joints for surface-mount components on printed wiring boards. The microstructures of the joints were evaluated and related to process parameters. Aging tests were conducted on these joints for times up to 300 days and at temperature up to 190C. The evolution of microstructure during aging was examined. The results showed that Sn-Ag solder microstructure is unstable at high temperature, and microstructural evolution can cause solder joint failure. Cu-Sn intermetallics in the solder and at copper-solder interfaces played an important role in both the microstructure evolution and failure of solder joints. Void and crack formation in the aged joints was also observed.

Yang, Wenge; Messler, Robert W.; Felton, Lawrence E.

1994-08-01

274

Traceable Co-C eutectic points for thermocouple calibration  

NASA Astrophysics Data System (ADS)

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.

Jahan, F.; Ballico, M. J.

2013-09-01

275

The electrodeposition of silver composites using deep eutectic solvents.  

PubMed

Silver is an important metal for electronic connectors, however, it is extremely soft and wear can be a significant issue. This paper describes how improved wear resistant silver coatings can be obtained from the electrolytic deposition of silver from a solution of AgCl in an ethylene glycol/choline chloride based Deep Eutectic Solvent. An up to 10-fold decrease in the wear volume is observed by the incorporation of SiC or Al(2)O(3) particles. The work also addresses the fundamental aspect of speciation of silver chloride in solution using EXAFS to probe solution structure. The size but not the nature of the composite particles is seen to change the morphology and grain size of the silver deposit. Grain sizes are shown to be consistent with previous nucleation studies. The addition of LiF is found to significantly affect the deposit morphology and improve wear resistance. PMID:22249451

Abbott, Andrew P; El Ttaib, Khalid; Frisch, Gero; Ryder, Karl S; Weston, David

2012-01-17

276

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)

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 -20.8C 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.

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

2005-12-01

277

Anelastic Response of Ice-I/Magnesium Sulfate Hydrate Eutectic Aggregates Obtained from Creep and Cyclic-Loading Experiments  

NASA Astrophysics Data System (ADS)

The large icy satellites of the giant planets are subjected to periodic stress due to their resonance-effected orbital eccentricity. The dissipation of this tidal elastic energy represents a potentially significant internal energy source, the magnitude of which depends on the anelastic properties of the various material layers (ice, rock, etc.). In an icy satellite incorporating an internal ocean, as is suggested for Europa, most of the tidal dissipation (attenuation) occurs in the outer ice layer. Current models for attenuation in the icy shell rely on the inversion of a Maxwell model of steady-state rheology because, to date, no direct dynamic measurements of energy absorption in polycrystalline ice at low-stress/low-frequency planetary conditions have been reported. We are pursuing transient and steady-state creep as well as direct attenuation measurements on polycrystalline ice-I and on eutectic aggregates of ice-I and salt hydrates, such as those suggested to be present on the surface of Europa by the near-infrared spectral data. We focus primarily on system H2O-MgSO4 because it represents the best (binary-system) fit to the spectral data. Samples are fabricated using a misting/sifting technique in order to obtain fine grain-size, or, more accurately, eutectic colony-size (< 25 ?m). Transformation of the time- domain data suggest the Maxwell model of steady state is inappropriate for understanding attenuation in pure ice, and wildly inappropriate for a ice-I/magnesium sulfate hydrate eutectic material, which demonstrates far higher attenuation (e.g., a factor of 102 at 1 Hz) than that predicted from the model. The absorption behavior of solid-state heterophase boundaries are argued as crucial in this behavior. Attenuation (cyclic compression- compression) experiments have commenced; we will report initial results, comparing these to earlier studies of the static response. Information gleaned from these experiment can help constrain models of crustal thickness and surface dynamics on Europa and icy satellites in general.

McCarthy, C.; Goldsby, D. L.; Cooper, R. F.

2007-12-01

278

Characterization of alumina/yttrium-aluminum garnet and alumina/yttrium-aluminum perovskite eutectics  

SciTech Connect

Alumina/yttrium-aluminum garnet (YAG) and alumina/yttrium-aluminum perovskite (YAP) eutectics were made by directional solidification. The two systems were characterized using transmitted polarized light microscopy, scanning electron microscopy, and transmission electron microscopy. The alumina/YAG system exhibited a degenerate eutectic with a Chinese script morphology, while the alumina/YAP eutectic had a rod/lamellae morphology. The c-axis of alumina was aligned perpendicular to the solidification direction, and elongated grains were aligned along the solidification direction in both systems. A single orientation relationship between alumina and YAG was observed. Several orientation relationships were observed in the alumina/YAP system. 5 refs.

Matson, L.E.; Hay, R.S.; Mah, T.

1990-08-01

279

Phase-field modeling of microelastically controlled eutectic lamellar growth in a Ti-Fe system  

NASA Astrophysics Data System (ADS)

We have developed a microelastical phase-field model to incorporate elastic energy and misfit stresses in eutectic growth. We apply the model to assess the formation of eutectic structures in Ti-Fe alloy, which exhibit high lattice mismatch owing to difference between lattice parameters of ?-Ti and FeTi phases. Numerical simulations of both directional and free eutectic growth are performed by applying cubic anisotropy to the Ti-Fe system. The resulted microstructures are presented and the corresponding stress distributions are evaluated.

Ebrahimi, Z.; Rezende, J. L.; Kundin, J.

2012-06-01

280

Structural and physical properties of rapidly solidified lead-bismuth eutectic alloy  

Microsoft Academic Search

Structure, internal friction, hardness, thermal, electrical and mechanical properties of the rapidly solidified Bi55.5Pb44.5 eutectic alloy have been investigated. X-ray diffraction and optical metallographic analysis show that the Bi55.5Pb44.5 eutectic alloy consists of rhombohedral bismuth phase, face centered cubic lead phase, and a metastable [(Pb-Bi)] phase. The physical properties such as thermal, electrical and mechanical properties of the Bi55.5Pb44.5 eutectic

Mustafa Kamal; Maher El-Tonsy; Abu Bakr El-Bediwi; Eman Kashita

2004-01-01

281

Microstructure and physical properties of bismuth-lead-tin ternary eutectic alloy  

NASA Astrophysics Data System (ADS)

Using different experimental techniques, microstructure, electrical resistivity, attenuation coefficient, and mechanical and thermal properties of the quenched Bi-Pb-Sn ternary eutectic alloy have been investigated. From the X-ray analysis, Bi3Pb7 and Bi-Sn meta-stable phases are detected, in addition to rhombohedral bismuth and Sn body-centered tetragonal phases. This study also compared the physical properties of the Bi-Sn-Pb ternary eutectic alloys with the base binary Bi-Sn and Bi-Pb eutectic alloys.

Kamal, M.; Moharram, B. M.; Farag, H.; El-Bediwi, A.; Abosheiasha, H. F.

2006-07-01

282

Electrodeposition of copper composites from deep eutectic solvents based on choline chloride.  

PubMed

Here we describe for the first time the electrolytic deposition of copper and copper composites from a solution of the metal chloride salt in either urea-choline chloride, or ethylene glycol-choline chloride based eutectics. We show that the deposition kinetics and thermodynamics are quite unlike those in aqueous solution under comparable conditions and that the copper ion complexation is also different. The mechanism of copper nucleation is studied using chronoamperometry and it is shown that progressive nucleation leads to a bright nano-structured deposit. In contrast, instantaneous nucleation, at lower concentrations of copper ions, leads to a dull deposit. This work also pioneers the use of the electrochemical quartz crystal microbalance (EQCM) to monitor both current efficiency and the inclusion of inert particulates into the copper coatings. This technique allows the first in situ quantification or particulate inclusion. It was found that the composition of composite material was strongly dependent on the amount of species suspended in solution. It was also shown that the majority of material was dragged onto the surface rather than settling on to it. The distribution of the composite material was found to be even throughout the coating. This technology is important because it facilitates deposition of bright copper coatings without co-ligands such as cyanide. The incorporation of micron-sized particulates into ionic liquids has resulted, in one case, in a decrease in viscosity. This observation is both unusual and surprising; we explain this here in terms of an increase in the free volume of the liquid and local solvent perturbation. PMID:19458829

Abbott, Andrew P; El Ttaib, Khalid; Frisch, Gero; McKenzie, Katy J; Ryder, Karl S

2009-03-26

283

Physical Chemistry of Molten Salt Batteries. Final Report for Period October 1, 1979-September 30, 1980. Current-Induced Composition Gradients in Molten LiCl-KCl.  

National Technical Information Service (NTIS)

Current induced composition gradients were demonstrated in the molten LiCl-KCl eutectic mixture, the electrolyte of an LiAl/LiCl-KCl/FeS/sub x/ battery. The gradients were produced by electrolysis of the salt between LiAl electrodes at currents of 50 to 1...

J. Braunstein S. Cantor C. E. Vallet

1981-01-01

284

Corrosion of Steels in Contact with Molten Salts as Latent Heat Storage Materials.  

National Technical Information Service (NTIS)

The corrosion behaviour of mild steel (St35.8), boiler steel 13CrMo44 and stainless steel X10CrNiMo1810 in contact with the eutectic salt mixtures AlCl sub 3 -NaCl, LiCl-LiNO sub 3 -NaCl, NaCl-NaNO sub 3 and KCl-LiCl is investigated. The test conditions a...

D. Heine

1985-01-01

285

On the stability of boron nitride with lithium alloy electrodes in molten salt cells  

Microsoft Academic Search

Experiments were carried out to determine the stability of boron nitride separator material in molten salt cells using lithium chloride-potassium chloride (LiCl-KCl) eutectic electrolyte and two stainless steel screen electrodes. The potentials of these electrodes were set by two separate electrical circuits and a lithium-silicon (Li-Si) reservoir electrode. The boron nitride separator was found stable at potentials above -136 mV

R. A. Sharma; T. G. Bradley

1981-01-01

286

Removal of alkaline-earth elements by a carbonate precipitation in a chloride molten salt  

Microsoft Academic Search

Separation of some alkaline-earth chlorides (Sr, Ba) was investigated by using carbonate injection method in LiCl-KCl eutectic and LiCl molten salts. The effects of the injected molar ratio of carbonate([K(or Li)CO\\/Sr(or Ba)Cl]) and the temperature(450-750 deg.) on the conversion ratio of the Sr or Ba carbonate were determined. In addition, the form of the Sr and Ba carbonate resulting from

Yung-Zun Cho; In-Tae Kim; Hee-Chui Yang; Hee-Chui Eun; Hwan-Seo Park; Eung-Ho Kim

2007-01-01

287

Preparation and characterization of single crystals and epitaxial layers of silicon carbide by molten salt electrolysis  

Microsoft Academic Search

The synthesis of silicon carbide by electrolysis of molten salts has been achieved for the first time. Two systems have been investigated, one involving K2SI F6 and LI2 CO3 Dissolved in a KF\\/LI F eutectic, the other being a combination of NA2 CO3 and Si O2 with Na BO3 and Li F. The latter system has given much more reproducible

T. H. Geballe; R. S. Feigelson; D. Elwell

1979-01-01

288

Novel room temperature molten salt electrolyte based on LiTFSI and acetamide for lithium batteries  

Microsoft Academic Search

A novel room temperature molten salt (RTMS) electrolyte composed of lithium bis(trifluoromethane sulfone)imide (LiN(SO2CF3)2, LiTFSI) and acetamide was found. Both LiTFSI and acetamide are solid at room temperature, but their mixture is a liquid at room temperature with a eutectic temperature of ?67 C at a molar ratio of 1:4 (LiTFSI:Acetamide). The room temperature ionic conductivities of some compositions of

Yongsheng Hu; Hong Li; Xuejie Huang; Liquan Chen

2004-01-01

289

Solidification of high temperature molten salts for thermal energy storage systems  

Microsoft Academic Search

The solidification of phase change materials for the high temperature thermal energy storage system of an advanced solar thermal power system has been examined theoretically. In light of the particular thermophysical properties of candidate phase change high temperature salts, such as the eutectic mixture of NaF - MgF2, the heat transfer characteristics of one-dimensional inward solidification for a cylindrical geometry

J. W. Sheffield

1981-01-01

290

Measurements of the partial electronic conductivity in lithium chloride - potassium chloride molten salts  

Microsoft Academic Search

The partial electronic conductivity of the lithium chloride-potassium chloride eutectic molten salt electrolyte has been studied as a function of lithium activity, temperature and melt composition using the Wagner asymmetric d-c polarization technique. Measurements were made over the temperature range 383-465°C and at lithium activities extending from 1.95 X 10⁻⁷ to unity. The results confirmed the applicability of this technique

G. J. Reynolds; R. A. Huggins; M. C. Y. Lee

1983-01-01

291

Synthesis and fluorescence properties of Y 2O 3:Eu by molten salt synthesis method  

Microsoft Academic Search

Red phosphors Y2O3:Eu were synthesized via molten salt synthesis method with the eutectic mixtures of KNO3-NaNO3 or KCl-NaCl as the fluxes. The as-prepared samples were investigated by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectrophotometer. The results showed that as-synthesized phosphors had good cubic crystallinity and the effect of annealing temperature on crystallinity was significant.

Xiaoyong WU; Yujun LIANG; Mingyu LIU; Rui CHEN; Yongzhou LI

2010-01-01

292

Molten salt synthesis of LaAlO 3 powder at low temperatures  

Microsoft Academic Search

Rhombohedral LaAlO3 powder was synthesised by reacting equimolar La2O3 and Al2O3 in a molten KFKCl eutectic salt for 3h between 630 and 800C. The lowest synthesis temperature (630C) is about 1000C lower than that of conventional mixed oxide synthesis, and close to or lower than those used by most wet chemical methods. The LaAlO3 particle size increased from <3 to

Zushu Li; Shaowei Zhang; William Edward Lee

2007-01-01

293

Anodic behavior of a carbon plate in an LiCl-KCl binary molten salt  

Microsoft Academic Search

The behavior of a negative pole of a carbon plate (a mixture of graphite with glassy carbon) in a eutectic LiCl-KCl binary molten salt has been investigated at 360500 C, as a fundamental study on high temperature lithium secondary cells. Both cyclic voltammetric and galvanostatic charge\\/discharge data suggested that reversible insertion\\/extraction of lithium can take place accompanied by stage formation.

Atsushi Adachi; Yasushi Katayama; Takashi Miura; Tomiya Kishi

1997-01-01

294

Diffusion behavior of actinide and lanthanide elements in molten salt for reductive extraction  

Microsoft Academic Search

In support of the development of reductive extraction, the diffusion coefficients of actinide and lanthanide ions in LiClKCl eutectic salt were measured by a capillary method. The temperature ranged from 723 to 873K. The obtained values of the diffusion coefficients are considerably high in the order of 10?9m2\\/s and no significant problem is found for the development of reductive extraction.

Daichi Yamada; Takayuki Murai; Kimikazu Moritani; Takayuki Sasaki; Ikuji Takagi; Hirotake Moriyama; Kensuke Kinoshita; Hajimu Yamana

2007-01-01

295

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

Microsoft Academic Search

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

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

1985-01-01

296

Molten salt destruction of energetic materials: Emission and absorption measurements  

Microsoft Academic Search

Spectroscopic aspects of decomposition behaviors of the high explosives LX-17 (92.5 wt % 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) plus 1.5 wt % Kel-F 800 plastic binder), LX-04 (85 wt % octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) plus 15 wt % Viton A plastic binder), and 2,6-Dinitrotoluene (DNT) were investigated when 0.3 or 1.0 g samples were immersed into molten salt baths (700 C molten LiC1-NaC1-KC1 eutectics). UV-VIS

Michelle L. Pantoya; Benjamin D. Shaw

2002-01-01

297

A study of the growth, structure, and properties of profiled eutectic composites of halide compounds  

NASA Astrophysics Data System (ADS)

Results of an experimental study are reported in which eutectic composites were produced on the basis of the binary eutectics of the following halides: NaCl-LiF; LiF-NaF, NaCl-NaF, NaF-CaF2, and CaF2-MgF2. Crystals of the eutectic composites, with a rod-like or a plate-like structural component embedded in a matrix of the other component, were grown from the melt using edge-defined film-fed crystal growth (a version of the Stepanov method) and Czochralski growth. The physicomechanical and optical properties of the eutectic composite crystals are examined in relation to their structural characteristics.

Rogalskii, G. I.; Vettegren, V. I.; Peller, V. V.; Khartmann, E.

1985-12-01

298

The Effect of Eutectic Microstructures on the Mechanical Properties of Ceramic Oxides.  

National Technical Information Service (NTIS)

Various experimental techniques for the production of unidirectionally solidified oxide eutectics were examined. These included a modified Bridgman-Starkbarger technique and bottom cooling of melts held in platinum crucibles. It was concluded that the bes...

C. O. Hulse J. A. Batt

1974-01-01

299

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

NASA Astrophysics Data System (ADS)

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.

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

2013-02-01

300

Solidification microstructure of laser floating zone remelted Al2O3/YAG eutectic in situ composite  

NASA Astrophysics Data System (ADS)

Alumina based eutectic in situ composite is now considered to be a promising candidate for ultrahigh temperature structural materials due to its excellent performance even close to its melting point. In this work, Laser Floating Zone (LFZ) solidification experiments have been performed on Al2O3/Y2O3 containing 18.5 mol% Y2O3 eutectic in situ composite at growth rate between 8 and 800 ?m/s. The solid/liquid (S/L) interface morphology of this system was reported. Based on the interface morphology, the lamellar selection mechanism of irregular eutectic systems was also discussed. The solidification microstructure evolution was studied, and the characteristic scale of irregular eutectic systems was analyzed using a mathematical model considering non-isothermal interface morphology. An important parameter, ?, which represents relationship between characteristic scales, was also given.

Song, K.; Zhang, J.; Jia, X. J.; Su, H. J.; Liu, L.; Fu, H. Z.

2012-04-01

301

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

SciTech Connect

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.

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

302

Cold-crucible directional solidification of refractory metal-silicide eutectics  

NASA Astrophysics Data System (ADS)

Microcomposite structures generated by directional solidification of eutectics offer many unique microstructural advantages, including thermodynamic stability, directional alignment, and a fine dispersion of component phases. In an effort to improve the performance of advanced turbine engines, a Czochralski crystal growth method in conjunction with cold-crucible induction melting has been developed for the production of high-temperature eutectic composites. Cold-crucible directional solidification has been successfully applied to the growth of refractory metal-silicide eutectics into directional microcomposites. The eutectics studied include Cr-Cr3Si,Nb-Nb3Si,and V-V3Si, which have melting temperatures ofl,705C, 1,880C, and 1,870C, respectively.

Chang, K.-M.; Bewlay, B. P.; Sutliff, J. A.; Jackson, M. R.

1992-06-01

303

Formation mechanism of the primary faceted phase and complex eutectic structure within an undercooled Ag-Cu-Ge alloy  

NASA Astrophysics Data System (ADS)

The solidified microstructure of bulk undercooled Ag40Cu30Ge30 alloy consists of three parts: primary (Ge) phase, the complex structure of (Ag + Ge) and (Ag + ? 2) pseudobinary eutectics, and (Ag + Ge + ? 2) ternary eutectic. In comparison, the pseudobinary eutectic no longer appears in an alloy droplet solidified in a drop tube. Once the undercooling exceeds 225 K and the cooling rate is greater than 2103 K s-1, the microstructure of the solidified droplet is totally composed of anomalous ternary eutectic. In both cases, the primary (Ge) phase exhibits various faceted growth morphologies at different undercoolings, such as columnar block, long dendrite, equiaxed dendrite and rod-like crystal. Some refined side branches grow from the equiaxed (Ge) dendritic branches composed of {111} twins, which is ascribed to the rapid epitaxial growth of (Ag + Ge) pseudobinary eutectic from the (Ge) dendritic branches. Moreover, both the primary (Ge) phase and the (Ge) phase in the (Ag + Ge) pseudobinary eutectic are effective heterogeneous nuclei for the (Ag+? 2) pseudobinary eutectic. As undercooling increases, the (Ge) phase in the (Ag + Ge+? 2) ternary eutectic transforms from faceted to non-faceted phase, while the independent nucleation and growth of the (Ag) and ? 2 phases in the ternary eutectic displaces their previous cooperative growth. These growth kinetics transitions result in the formation of anomalous ternary eutectic.

Ruan, Y.; Dai, F. P.; Wei, B.

2010-11-01

304

Formation mechanism of the primary faceted phase and complex eutectic structure within an undercooled Ag-Cu-Ge alloy  

NASA Astrophysics Data System (ADS)

The solidified microstructure of bulk undercooled Ag40Cu30Ge30 alloy consists of three parts: primary (Ge) phase, the complex structure of (Ag + Ge) and (Ag + ? 2) pseudobinary eutectics, and (Ag + Ge + ? 2) ternary eutectic. In comparison, the pseudobinary eutectic no longer appears in an alloy droplet solidified in a drop tube. Once the undercooling exceeds 225 K and the cooling rate is greater than 2103 K s-1, the microstructure of the solidified droplet is totally composed of anomalous ternary eutectic. In both cases, the primary (Ge) phase exhibits various faceted growth morphologies at different undercoolings, such as columnar block, long dendrite, equiaxed dendrite and rod-like crystal. Some refined side branches grow from the equiaxed (Ge) dendritic branches composed of {111} twins, which is ascribed to the rapid epitaxial growth of (Ag + Ge) pseudobinary eutectic from the (Ge) dendritic branches. Moreover, both the primary (Ge) phase and the (Ge) phase in the (Ag + Ge) pseudobinary eutectic are effective heterogeneous nuclei for the (Ag+ ? 2) pseudobinary eutectic. As undercooling increases, the (Ge) phase in the (Ag + Ge+ ? 2) ternary eutectic transforms from faceted to non-faceted phase, while the independent nucleation and growth of the (Ag) and ? 2 phases in the ternary eutectic displaces their previous cooperative growth. These growth kinetics transitions result in the formation of anomalous ternary eutectic.

Ruan, Y.; Dai, F. P.; Wei, B.

2011-07-01

305

Research on the mechanism of thermal fatigue in near-eutectic Pb-Sn solders  

Microsoft Academic Search

This paper discusses the microstructures of solder joints and the mechanisms of thermal fatigue, which is an important source of failure in electronic devices. The solder joints studied were near-eutectic Pb--Sn solder contacts on copper. The microstructure of the joints is described. While the fatigue life of near-eutectic solder joints is strongly dependent on the operating conditions and on the

J. W. Jr. Morris; D. Grivas; D. Tribula; T. Summers; D. Frear

1989-01-01

306

Studies on phase transformations in a rapidly solidified Ni-base eutectic superalloy  

Microsoft Academic Search

Few systematic studies of the phase transformation in Ni-Al-Mo alloys has been reported despite the engineering importance of this eutectic system. In this work, eutectic Ni-base superalloys with small additions of V and Re or Cr were melt-spun at different wheel speeds. The highly supersaturated microstructure resulting from the chilled block metal spinning (CBMS) process was used as a basis

1988-01-01

307

Mechanical properties of eutectic alloys ?-NiAl + ?-Re and spray coatings  

Microsoft Academic Search

We have studied the structure and mechanical properties of eutectic alloys ?-NiAl + ?-Re of the ternary system Ni-Al-Re. We\\u000a have established that the best combination of mechanical characteristics, determined by local loading with a rigid indentor,\\u000a is exhibited by the alloy containing 2.5 at.% Re, the structure of which consists of the eutectic ?-NiAl + ?-Re. Rhenium inclusions\\u000a can

V. E. Oliker; M. Yu. Barabash; E. F. Grechishkin; I. S. Martsenyuk; Yu. N. Podrezov; V. F. Gorban

2006-01-01

308

Comparison of nickel carbon and iron carbon eutectic fixed point cells for the calibration of thermocouples  

Microsoft Academic Search

Three nickel-carbon (Ni-C) and three iron-carbon (Fe-C) eutectic fixed points cells of a new design, meeting the requirements for reliable applications and being suitable for the calibration of thermocouples, were constructed at PTB and Inmetro. Their melting temperatures were compared by using the high-temperature furnace of PTB (HTF-R) and two platinum\\/palladium (Pt\\/Pd) thermocouples. The measured emfs of the Ni-C eutectic

F. Edler; A. C. Baratto

2006-01-01

309

Oxygen partial pressure: a key to alloying and discovery in metal oxide--metal eutectic systems  

Microsoft Academic Search

Control of oxygen partial pressure is essential in the directional solidification of oxide--metal eutectic composites by techniques involving gas-solid and gas-liquid interactions. The existence of end components in the eutectic composite is Po sensitive as are melt stoichiometry, solid phase compositions, and vapor losses due to oxidation-volatilization. Simple criteria are postulated which can aid the experimentalist in selecting the proper

J. D. Holder; G. W. Clark; B. F. Oliver

1978-01-01

310

Solidliquid interfacial energy for solid succinonitrile in equilibrium with succinonitrile dichlorobenzene eutectic liquid  

Microsoft Academic Search

The equilibrated grain boundary groove shapes for solid succinonitrile (SCN) in equilibrium with the succinonitrile (SCN) dichlorobenzene (DCB) eutectic liquid were directly observed. From the observed grain boundary groove shapes, the GibbsThomson coefficient and solidliquid interfacial energy for solid SCN in equilibrium with the SCN DCB eutectic liquid have been determined to be (5.430.27)10?8Km and (7.950.80)10?3Jm?2 with present numerical method

Y. Ocak; S. Akbulut; U. Byk; M. Erol; K. Ke?lio?lu; N. Mara?l?

2006-01-01

311

Thermophysical properties of the liquid Pb84.1Au15.9 eutectic alloy  

NASA Astrophysics Data System (ADS)

Lead-gold eutectic alloy is under consideration as target material of spallation sources. The thermohydraulic design of such a target or related coolant systems requires a reliable data basis regarding the temperature dependent physical properties of such alloys. We present measurements of the electrical and thermal conductivity, thermoelectric power, viscosity and surface tension for liquid Pb84.1Au15.9 alloy of eutectic composition in a wide temperature range between the melting point and about 1000 K.

Plevachuk, Yu.; Sklyarchuk, V.; Yakymovych, A.; Eckert, S.; Gerbeth, G.

2013-03-01

312

Breakup of eutectic carbide network of white cast irons at high temperatures  

Microsoft Academic Search

The fracture toughness of white cast irons is related to the morphology of eutectic carbides,being better when isolated than when network-like. In this paper observations on the breakup of eutectic cementite network during annealing treatment of white cast irons are reported using a high temperature microscope and scanning electron microscopy (SEM). Dissolution-induced breakup and capillarity-induced breakup are identified. The former

Ma Qian; Liu Baicheng; Wang Zhaochang

1995-01-01

313

Monotonic and fatigue deformation of Ni-W directionally solidified eutectic  

Microsoft Academic Search

Unlike many eutectic composites, the Ni-W eutectic exhibits extensive ductility by slip. Furthermore, its properties may be\\u000a greatly varied by proper heat treatments. Here results of studies of deformation in both monotonic and fatigue loading are\\u000a reported. During monotonie deformation the fiber \\/matrix interface acts as a source of dislocations at low strains and an\\u000a obstacle to matrix slip at

G. Garmong; J. C. Williams

1975-01-01

314

Localized silicon fusion and eutectic bonding for MEMS fabrication and packaging  

Microsoft Academic Search

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,

Y. T. Cheng; Liwei Lin; Khalil Najafi

2000-01-01

315

Fluxless bondings of silicon to alumina substrate using electroplated eutectic Au-Sn solder  

Microsoft Academic Search

Large 6 mm times 9 mm silicon dice have been successfully bonded on alumina substrate with electroplated Au80Sn20 eutectic alloy. Eutectic AuSn is one of the best known hard solders having excellent fatigue-resistance and mechanical properties. A fluxless bonding process in 50 militorrs of vacuum environment is presented. Vacuum environment is employed to prevent tin oxidation during the process. The

Jong S. Kim; Won S. Choi; A. Shkel; C. C. Lee

2006-01-01

316

A creep-rupture model for two-phase eutectic solders  

Microsoft Academic Search

An analytical framework to predict failure of solders under creep conditions is proposed. A creep-rupture model for two-phase eutectic solders, based on both micromechanics and fracture mechanics, has been developed. The general agreement between the model predictions and reported creep-rupture data in the literature for lead\\/tin eutectic solder indicates that the mode and mechanisms proposed in the model may control

B. Wong; D. E. Helling; R. W. Clark

1988-01-01

317

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

NASA Astrophysics Data System (ADS)

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.

Wang, Weili; Dai, Fuping; Wei, Bingbo

2007-08-01

318

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

SciTech Connect

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.

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

319

Evaluation and modeling of the eutectic composition of various drug-polyethylene glycol solid dispersions.  

PubMed

The purpose of this study was to gain a better understanding of which factors contribute to the eutectic composition of drug-polyethylene glycol (PEG) blends and to compare experimental values with predictions from the semi-empirical model developed by Lacoulonche et al. Eutectic compositions of various drug-PEG 3350 solid dispersions were predicted, assuming athermal mixing, and compared to experimentally determined eutectic points. The presence or absence of specific interactions between the drug and PEG 3350 were investigated using Fourier transform infrared (FT-IR) spectroscopy. The eutectic composition for haloperidol-PEG and loratadine-PEG solid dispersions was accurately predicted using the model, while predictions for aceclofenac-PEG and chlorpropamide-PEG were very different from those experimentally observed. Deviations in the model prediction from ideal behavior for the systems evaluated were confirmed to be due to the presence of specific interactions between the drug and polymer, as demonstrated by IR spectroscopy. Detailed analysis showed that the eutectic composition prediction from the model is interdependent on the crystal lattice energy of the drug compound (evaluated from the melting temperature and the heat of fusion) as well as the nature of the drug-polymer interactions. In conclusion, for compounds with melting points less than 200C, the model is ideally suited for predicting the eutectic composition of systems where there is an absence of drug-polymer interactions. PMID:20141502

Baird, Jared A; Taylor, Lynne S

2010-02-09

320

Edge Drift of Eutectic SnPb Lines: Electromigration of Flip Chip Solder  

NASA Astrophysics Data System (ADS)

We have investigated the characteristics of eutectic SnPb electromigration using edge drift structure. An incubation stage for the edge drift was observed in the eutectic SnPb electromigration, i.e. there was a time duration before an edge began to move. During the incubation stage for the edge drift, depletion of Pb at the cathode end was observed. From the change of resistance, the activation energies for the incubation stage and for edge movement stage were calculated to be 0.88 eV and 1.02 eV, respectively. Comparing the activation energies for each stage with the reported values of Pb in eutectic SnPb and those of Sn in Sn, Pb we found that during the incubation stage, Pb migrated before Sn, and the edge movement is resulted from migration of Sn. These results suggested that Pb depletion is a prerequisite for the electromigration-induced void nucleation in eutectic SnPb solder. Threshold current density of eutectic SnPb was measured as a function of line length, and it did not change with line lengths significantly. This result indicated that the Blech product in eutectic SnPb did not agree on that in Al interconnect.

Joo, Y.-C.; Yoon, M.-S.; Ko, M.-K.; Kim, O.-H.; Kim, B.-N.; Park, Y.-B.

2006-02-01

321

Comparative study of dielectric properties of MgNb 2 O 6 prepared by molten salt and ceramic method  

Microsoft Academic Search

Magnesium niobate (MgNb2O6) powder was synthesized by the conventional ceramic route as well as by the molten salt route using a eutectic mixture of\\u000a NaCl-KCl as the salt and Mg(NO3)2-6H2O and TiO2 as the starting materials. Pure phase of MgNb2O6 could be obtained by the molten salt method at 1100C. However, in ceramic method the pure phase of MgNb2O6 was

Vishnu Shanker; Ashok K. Ganguli

2003-01-01

322

Theoretical Investigation of Binary Eutectic Alloy Nanoscale Phase Diagrams  

NASA Astrophysics Data System (ADS)

Recently, embedded binary eutectic alloy nanostructures (BEANs) have drawn some attention. A previously calculated equilibrium structure map predicts four possible nanocrystal alloy morphologies: phase-separated, bi-lobe, core-shell and inverse core-shell governed by two dimensionless interface energy parameters. The shape of the bilobe nanoparticles is obtained by finding the surface area of all interfaces that minimizes the overall energy, while also maintaining mechanical equilibrium at the triple point. Two representative alloy systems displaying eutectic phase diagrams and negligible solid solubility were chosen: GeSn and AuGe. GeSn samples were prepared by sequential implantation of Ge and Sn into SiO2. AuGe samples were prepared by implanting Ge within Au-doped silica films. Transmission electron microscopy images revealed bi-lobe nanocrystals in both samples. Therefore, the interface energies in both systems must be such that the dimensionless parameters lie in the region of bi-lobe stability. Careful analysis of the bi-lobe structure leads to the determination of two dimensionless length scales, which describe the bi-lobe independent of the size of the nanoparticle. These two parameters, eta 1 and eta 2 can be used to calculate contours of equal eta 1 and eta 2 over the entire range of bi-lobe stability. Experimental measurement and comparison to predicted structures leads to determination of acting dimensionless interface energies. Experimentally available wetting data is then used to calculate the remaining interface energies in the system. gamma Ge(s)/SiO2 was found to be between 0.82-0.99 J/m2 . gamma Ge0.22Sn0.78(l)/SiO2 and gamma Au0.53Ge0.47(l)/SiO2 are determined to be 1.20 and 0.94 J/m2 , respectively. To investigate the possibility of size effects at the nanoscale, size dependent phase diagrams for the AuGe and GeSn system are determined. This is done by the theoretical approach first outlined by Weissmueller et al., which takes into account the energy contribution of the various morphologies listed above. Results from this calculation are compared to those using the tangent line construction approach. The composition dependent surface energies of binary alloy liquids required in this calculation are determined using Butler's equation.

Boswell-Koller, Cosima Nausikaa

323

Energetic salts based on dipicrylamine and its amino derivative.  

PubMed

Energetic salts based on dipicrylamine and its amino derivative were synthesized. All salts were fully characterized by multinuclear NMR spectroscopy ((1)H, (13)C), vibrational spectroscopy (IR), and elemental analysis. Ethylenediammonium di-DPA (DPA=dipicrylamine) and 1,3-diaminoguanidinium DPA were further confirmed by single-crystal X-ray diffraction. These salts exhibit reasonable physical properties, such as high densities (1.71-1.81 g cm(-3)), good thermal stabilities (T(d) =155-285 C), and low solubilities in water. The impact sensitivity of 1-methyl-3,4,5-triamino-1,2,4-triazolium DPA is lower than that of 2,4,6-trinitrotoluene (TNT), and for some other energetic salts their impact sensitivities are comparable to that of TNT. Based on experimental densities and theoretical calculations carried out by using the Gaussian 03 suite of programs, all the salts have calculated detonation pressures (22.5-27.8 GPa) and velocities (7226-7917 m s(-1)) that exceed those of conventional TNT. The toxicities of these salts measured by luminescent bacteria toxicity tests are much lower than that of TNT, and two binary eutectic mixtures with melting points that fall between 70 and 100 C were identified. PMID:22038898

Huang, Haifeng; Zhou, Zhiming; Song, Jinhong; Liang, Lixuan; Wang, Kai; Cao, Dan; Sun, Wenwen; Dong, Xuemin; Xue, Min

2011-10-31

324

Directional solidification of Ni-Ni3Si eutectic in situ composites by electron beam floating zone melting  

NASA Astrophysics Data System (ADS)

Combining the intermetallic compound with the ductile metal at the eutectic composition is one promising method to improve the ductility of the intermetallic compound. This paper reports the microstructure and the micro-hardness of the Ni-Ni3Si eutectic in situ composites prepared by electron beam floating zone melting technique. Ni-Ni3Si eutectic in situ composites display regular lamellar eutectic structure at the solidification rate R=0.3-4.0 mm/min. The lamellar spacing is decreased with the increase of the solidification rate. The phase composition of the Ni-Ni3Si eutectic in situ composites is also determined by X-ray diffraction. Ni-Ni3Si eutectic in situ composites present lower micro-hardness than pure Ni3Si, although a small quantity of metastable Ni31Si12 phase is formed during the directional solidification process.

Cui, Chunjuan; Zhang, Jun; Wu, Kun; Zou, Dening; Ma, Youping; Liu, Lin; Fu, Hengzhi

2013-03-01

325

Eutectic phases in ice facilitate nonenzymatic nucleic acid synthesis.  

PubMed

Polymeric compounds similar to oligonucleotides are relevant to the origin of life and particularly to the concept of an RNA world. Although short oligomers of RNA can be synthesized nonenzymatically under laboratory conditions by second-order reactions in concentrated solutions, there is no consensus on how these polymers could have been synthesized de novo on the early Earth from dilute solutions of monomers. To address this question in the context of an RNA world, we have explored ice eutectic phases as a reaction medium. When an aqueous solution freezes, the solutes become concentrated in the spaces between the ice crystals. The increased concentration offsets the effect of the lower temperature and accelerates the reaction. Here we show that in the presence of metal ions in dilute solutions, frozen samples of phosphoimidazolide-activated uridine react within days at -18 degrees C to form oligouridylates up to 11 bases long. Product yields typically exceed 90%, and approximately 30% of the oligomers include one or more 3'-5' linkages. These conditions facilitate not only the notoriously difficult oligouridylate synthesis, but also the oligomerization of activated cytidylate, adenylate, and guanylate. To our knowledge, this represents the first report to indicate that ice matrices on the early Earth may have accelerated certain prebiotic polymerization reactions. PMID:12448990

Kanavarioti, A; Monnard, P A; Deamer, D W

2001-01-01

326

Microanalysis of an oxidized cobalt oxide: Zirconia eutectic  

SciTech Connect

The compositions of CoO, Co{sub 3}O{sub 4}, and Ca-stabilized cubic ZrO{sub 2} in an oxidized directionally solidified CoO-ZrO{sub 2} eutectic were determined by PEELS and EDS. An oxygen gradient exists across the Co{sub 3}O{sub 4} with highest levels near the ZrO{sub 2} interface. Oxygen ELNES for CoO and Co{sub 3}O{sub 4} are quite different; published oxygen ELNES have been incorrectly attributed to CoO. Normalized Co-L{sub 23} white line intensity (WLI) ratios for CoO and Co{sub 3}O{sub 4} are similar (0.53 {plus_minus} 0.02) but L{sub 3}/L{sub 2} WLI ratios are 3.88 and 2.58, respectively. ELCE data suggest Co{sub 3}O{sub 4} has the inverse spinel structure.

Bentley, J. [Oak Ridge National Lab., TN (United States); McKernan, S.; Carter, C.B. [Minnesota Univ., Minneapolis, MN (United States). Dept. of Chemical Engineering and Materials Science; Revcolevschi, A. [Laboratoire de Chimie des Solides, Universite de Paris-Sud, Batiment, Orsay Cedex (France)

1993-12-31

327

Molten salt synthesis of LiMn 2O 4 using chloridecarbonate melt  

Microsoft Academic Search

Lithium manganese oxide powders have been successfully prepared by molten salt synthesis (MSS) route using the eutectic mixture of LiCl, MnCl24H2O and Li2CO3 salts. The synthesis was performed at 700C using an electrical resistance furnace. The crystalline powders were characterized using TGA\\/DTA, XRD, FT-IR, AAS, CHNS, EDAX, EPR and SEM analyses. The lattice constant value for LiMn2O4 is a=8.1834. The

M. Helan; L. John Berchmans; Timy P. Jose; A. Visuvasam; S. Angappan

2010-01-01

328

Molten salt synthesis of lead lanthanum zirconate titanate stannate powders and ceramics  

Microsoft Academic Search

Powders and ceramics with a composition (Pb0.97La0.02) (Zr0.66Sn0.27Ti0.07)O3 were prepared by the molten salt synthesis (MSS) method, using Li2SO4Na2SO4 and NaClKCl eutectic mixtures as the flux. The influences of processing parameters, such as temperature, time, and type of molten salts, on the formation and sinterability of PLZST were investigated. XRD and SEM were used for characterization of the as-prepared powders

Shixi Zhao; Qiang Li; Lin Wang; Yiling Zhang

2006-01-01

329

Coal gasification by CO 2 gas bubbling in molten salt for solar\\/fossil energy hybridization  

Microsoft Academic Search

Coal gasification with CO2 (the Boudouard reaction: C+CO2=2CO, ?rH=169.2 kJ\\/mol at 1150 K), which can be applied to a solar thermochemical process to convert concentrated solar heat into chemical energy, was conducted in the molten salt medium (eutectic mixture of Na2CO3 and K2CO3, weight ratio=1\\/1) to provide thermal storage. When CO2 gas was bubbled through the molten salt, higher reaction

Jun Matsunami; Shinya Yoshida; Yoshinori Oku; Osamu Yokota; Yutaka Tamaura; Mitsunobu Kitamura

2000-01-01

330

Preliminary study of the electrolysis of aluminum sulfide in molten salts  

SciTech Connect

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.

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

1983-02-01

331

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

PubMed

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 FT-IR analysis was used to investigated the nature of the interaction. Permeation of ibu across human epidermal membrane from the eutectic system was measured and compared to the flux from a saturated aqueous solution across skin and skin pretreated with the terpenes. The eutectic, i.e. minimum, melting points of these systems ranged from 32 degrees C for ibu:thymol 40:60 (% w/w) to -13 degrees C for ibu:1,8-cineole 40:60 (% w/w) compared to 76 degrees C for ibu alone. FT-IR studies indicated that only the terpenes which formed hydrogen bonds with ibu produced eutectic systems. Each set of ibu:terpene eutectic systems produced a significant (t-test, p = 0.05) increase in flux compared to a saturated aqueous solution applied to untreated and to terpene pretreated skin. For example, ibu:thymol 40:60 (% w/w) produced a flux of 150 micrograms/cm2/h, 5.9 times the flux from a saturated aqueous solution with thymol pretreated skin and 12.7 times the flux from a saturated aqueous solution across non-pretreated skin. In conclusion, a hydrogen bonding interaction is the primary mechanism by which some terpenes form binary eutectic mixtures with ibu. The resultant melting point depression of the delivery system is correlated with a significant increase in transdermal permeation. PMID:9685897

Stott, P W; Williams, A C; Barry, B W

1998-01-01

332

Fission product ion exchange between zeolite and a molten salt  

NASA Astrophysics Data System (ADS)

The electrometallurgical treatment of spent nuclear fuel (SNF) has been developed at Argonne National Laboratory (ANL) and has been demonstrated through processing the sodium-bonded SNF from the Experimental Breeder Reactor-II in Idaho. In this process, components of the SNF, including U and species more chemically active than U, are oxidized into a bath of lithium-potassium chloride (LiCl-KCl) eutectic molten salt. Uranium is removed from the salt solution by electrochemical reduction. The noble metals and inactive fission products from the SNF remain as solids and are melted into a metal waste form after removal from the molten salt bath. The remaining salt solution contains most of the fission products and transuranic elements from the SNF. One technique that has been identified for removing these fission products and extending the usable life of the molten salt is ion exchange with zeolite A. A model has been developed and tested for its ability to describe the ion exchange of fission product species between zeolite A and a molten salt bath used for pyroprocessing of spent nuclear fuel. The model assumes (1) a system at equilibrium, (2) immobilization of species from the process salt solution via both ion exchange and occlusion in the zeolite cage structure, and (3) chemical independence of the process salt species. The first assumption simplifies the description of this physical system by eliminating the complications of including time-dependent variables. An equilibrium state between species concentrations in the two exchange phases is a common basis for ion exchange models found in the literature. Assumption two is non-simplifying with respect to the mathematical expression of the model. Two Langmuir-like fractional terms (one for each mode of immobilization) compose each equation describing each salt species. The third assumption offers great simplification over more traditional ion exchange modeling, in which interaction of solvent species with each other is considered. (Abstract shortened by UMI.)

Gougar, Mary Lou D.

333

Ionic liquid analogues formed from hydrated metal salts.  

PubMed

A dark green, viscous liquid can be formed by mixing choline chloride with chromium(III) chloride hexahydrate and the physical properties are characteristic of an ionic liquid. The eutectic composition is found to be 1:2 choline chloride/chromium chloride. The viscosity and conductivity are measured as a function of temperature and composition and explained in terms of the ion size and liquid void volume. The electrochemical response of the ionic liquid is also characterised and it is shown that chromium can be electrodeposited efficiently to yield a crack-free deposit. This approach could circumvent the use of chromic acid for chromium electroplating, which would be a major environmental benefit. This method of using hydrated metal salts to form ionic liquids is shown to be valid for a variety of other salt mixtures with choline chloride. PMID:15281161

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

2004-08-01

334

Factors affecting the formation of eutectic solid dispersions and their dissolution behavior.  

PubMed

The objective of this work was to obtain a fundamental understanding of the factors, specifically the properties of poorly water-soluble drugs and water-soluble carriers, which influence predominantly, the formation of eutectic or monotectic crystalline solid dispersion and their dissolution behavior. A theoretical model was applied on five poorly water-soluble drugs (fenofibrate, flurbiprofen, griseofulvin, naproxen, and ibuprofen) having diverse physicochemical properties and water-soluble carrier (polyethylene glycol (PEG) 8000) for the evaluation of these factors. Of these, two drugs, fenofibrate and flurbiprofen, and PEG of different molecular weights (3350, 8000, and 20000), were chosen as model drugs and carriers for further investigation. Experimental phase diagrams were constructed and dissolution testing was performed to assess the performance of the systems. The theoretical model predicted the formation of eutectic or monotectic solid dispersions of fenofibrate, griseofulvin, ibuprofen, and naproxen with PEG, holding the contribution of specific intermolecular interactions between compound and carrier to zero. In the case of the flurbiprofen-PEG eutectic system, intermolecular interactions between drug and polymer needed to be taken into consideration to predict the experimental phase diagram. The results of the current work suggest that the thermodynamic function of melting point and heat of fusion (as a measure of crystal energy of drug) plays a significant role in the formation of a eutectic system. Lipophilicity of the compound (as represented by cLog P) was also demonstrated to have an effect. Specific interactions between drug and carrier play a significant role in influencing the eutectic composition. Molar volume of the drug did not seem to have an impact on eutectic formation. The polymer molecular weight appeared to have an impact on the eutectic composition for flurbiprofen, which exhibits specific interactions with PEG, whereas no such impact of polymer molecular weight on eutectic composition was observed for fenofibrate, which does not exhibit specific interactions with PEG. The impact of polymer molecular weight on dissolution of systems where specific drug-polymer interactions are exhibited was also observed. The current work provides valuable insight into factors affecting formation and dissolution of eutectic systems, which can facilitate the rational selection of suitable water-soluble carriers. PMID:17051588

Vippagunta, Sudha R; Wang, Zeren; Hornung, Stefanie; Krill, Steven L

2007-02-01

335

PU/SS EUTECTIC ASSESSMENT IN 9975 PACKAGINGS IN A STORAGE FACILITY DURING EXTENDED FIRE  

SciTech Connect

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.

Gupta, N.

2012-03-26

336

Enhanced intestinal absorption of daidzein by borneol/menthol eutectic mixture and microemulsion.  

PubMed

In the present study, the effect of a borneol/menthol eutectic mixture (25:75) and microemulsion on the absorption of daidzein in rat intestinal membrane was evaluated. The microemulsion formulation was composed of ethyl oleate (oil), Cremophor RH40 (surfactant), PEG400 (co-surfactant), and water. The borneol/menthol eutectic mixture and its microemulsion were found to enhance the intestinal absorption of daidzein in vitro. A diffusion chamber system with isolated rat intestinal membranes was used. In contrast, verapamil (0.3 mM), a typical P-glycoprotein inhibitor, showed no effect on the absorption of daidzein by this system. A pharmacokinetic study was conducted in rats. After oral administration of daidzein at a dose of 10 mg/kg in the form of either borneol/menthol eutectic mixtures or suspension, the relative bioavailability of borneol/menthol eutectic mixtures and microemulsion was enhanced by about 1.5- and 3.65-fold, respectively, compared with a daidzein suspension. In conclusion, a borneol/menthol eutectic mixture can enhance the absorption of daidzein, although the mechanism of absorption enhancement is still unclear. PMID:21842308

Shen, Qi; Li, Xi; Li, Wenji; Zhao, Xinyi

2011-08-13

337

Modeled Salt Density for Nuclear Material Estimation in the Treatment of Spent Nuclear Fuel  

SciTech Connect

Spent metallic nuclear fuel is being treated in a pyrometallurgical process that includes electrorefining the uranium metal in molten eutectic LiCl-KCl as the supporting electrolyte. We report a model for determining the density of the molten salt. Inventory operations account for the net mass of salt and for the mass of actinides present. It was necessary to know the molten salt density but difficult to measure, and it was decided to model the salt density for the initial treatment operations. The model assumes that volumes are additive for the ideal molten salt solution as a starting point; subsequently a correction factor for the lanthanides and actinides was developed. After applying the correction factor, the percent difference between the net salt mass in the electrorefiner and the resulting modeled salt mass decreased from more than 4.0% to approximately 0.1%. As a result, there is no need to measure the salt density at 500 C for inventory operations; the model for the salt density is found to be accurate.

DeeEarl Vaden; Robert. D. Mariani

2010-09-01

338

Solidification processing of eutectic alloys; Proceedings of the Symposium, Cincinnati, OH, Oct. 12-15, 1987  

SciTech Connect

The papers presented in this volume address the effect of solidification processing variables, such as cooling rate, nucleation hierarchy, and the faceted or nonfaceted nature of the constituent phases, on the eutectic morphology and resulting properties. Topics discussed include the current status of the modeling of eutectic growth and directional solidification experiments on a variety of alloys, such as aluminum foundry alloy A 356, Si- and GaAs-based eutectics for electronic applications, and Cu-Al in-situ composites. Particular attention is given to undercooled and rapidly solidified alloys, including classical simple alloys, such as Pb-Sn as well as more complicated alloys such as Nb-Si, alumina-zirconia, and Cr90Ta10.

Stefanescu, D.M.; Abbaschian, G.J.; Bayuzick, R.J.

1988-01-01

339

Electrochemical behavior of silicon compound in LiFNaFKFNa 2 SiF 6 molten salt  

Microsoft Academic Search

The electrochemical reduction and nucleation process of Si4+ on an electrical steel electrode in the eutectic LiFNaFKF molten salt were investigated at 750C, by means of cyclic voltammetry\\u000a and chronoamperometry technique. Silicon was electrodeposited on steel, and Fe3Si was formed by the diffusivity of silicon on the electrode surface. The electrochemical reduction of Si4+ process in single-step charge transfer and

Zongying Cai; Yungang Li; Wei Tian

340

Physical and electrochemical properties of new binary room-temperature molten salt electrolyte based on LiBETI and acetamide  

Microsoft Academic Search

A new binary room-temperature molten salt electrolyte based on lithium bis(perfluoroethysulfonyl) imide (LiN(SO2C2F5)2, LiBETI) and acetamide has been prepared and characterized by differential scanning calorimetry (DSC), IR, Raman spectroscopy, ac impedance, and cyclic voltammetry, etc. Both LiBETI and acetamide are solid, but their mixture is a liquid at room temperature with a eutectic temperature of ?57 C at a molar

Yongsheng Hu; Zhaoxiang Wang; Xuejie Huang; Liquan Chen

2004-01-01

341

Separation behaviors of actinides from rare-earths in molten salt electrorefining using saturated liquid cadmium cathode  

Microsoft Academic Search

Electrorefining in the molten LiClKCl eutectic salt containing actinide (An) and rare-earth (RE) elements was conducted to recover An elements up to 10wt% into liquid cadmium (Cd) cathode, which is much higher than the solubility of the An elements in liquid Cd at the experimental temperature of 773K. In the saturated Cd cathode, the An and RE elements were recovered

Tetsuya Kato; Tadashi Inoue; Takashi Iwai; Yasuo Arai

2006-01-01

342

ELECTROCHEMICAL BEHAVIOURS OF LANTHANIDE FLUORIDES IN THE ELECTROLYSIS SYSTEM WITH LiF-NaF-KF SALT  

Microsoft Academic Search

As a part of partitioning studies, the experiments of cyclic voltammetry and electrolytic reduction with the liquid bismuth cathode were conducted to investigate electrochemical behaviours of lanthanide elements in the electrorefining system employing LiF-NaF-KF eutectic salt as the electrolyte. The cyclic voltammograms for NdF3 and GdF3 were obtained at various potential scan rates, respectively. The cathodic and anodic peak currents

Joon-Bo Shim; Sung-Chan Hwang; Eung-Ho Kim; Young-Ho Kang; Byung-Jik Lee; Jae-Hyung Yoo

343

Ceramic foam as a potential molten salt oxidation catalyst support in the removal of soot from diesel exhaust gas  

Microsoft Academic Search

An exploratory study has been carried out to determine the potential of open-pore ceramic foam as support for molten-salt diesel soot oxidation catalysts. These catalysts are based on eutectic mixtures of Cs2O, V2O5, MoO3, and Cs2SO4. Open-pore ceramic foams are very interesting, since they can act as supports and as soot filters. 50ppi ?-alumina foam has been tested as support

B. A. A. L van Setten; J Bremmer; S. J Jelles; M Makkee; J. A Moulijn

1999-01-01

344

Electrolyte salts for power sources  

DOEpatents

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.

Doddapaneni, N.; Ingersoll, D.

1995-11-28

345

Electrolyte salts for power sources  

DOEpatents

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.

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

1995-01-01

346

Molten salt extraction (MSE) of americium from plutonium metal in CaCl{sub 2}-KCl-PuCl{sub 3} and CaCl{sub 2}-PuCl{sub 3} salt systems  

SciTech Connect

Molten salt extraction (MSE) of americium-241 from reactor-grade plutonium has been developed using plutonium trichloride salt in stationary furnaces. Batch runs with oxidized and oxide-free metal have been conducted at temperature ranges between 750 and 945C, and plutonium trichloride concentrations from one to one hundred mole percent. Salt-to-metal ratios of 0.10, 0.15, and 0 30 were examined. The solvent salt was either eutectic 74 mole percent CaCl{sub 2}{endash}26 mole percent KCl or pure CaCl{sub 2}. Evidence of trivalent product americium, and effects of temperature, salt-to-metal ratio, and oxide contamination on the americium extraction efficiency are given. 24 refs, 20 figs, 13 tabs.

Dodson, K.E.

1992-06-11

347

Salt Bath Furnaces  

Microsoft Academic Search

A salt bath furnace is basically a ceramic or metal container filled with molten salt into which work is immersed for either heating or cooling. The furnace contains salt such as nitrates, nitrites, caustic soda, chlorides, carbonates, and cyanide. Mixtures of salt are selected to give a specific temperature range and a desired treatment (or lack of treatment) to the

Gordon W. Anderson

1974-01-01

348

Gas releases from salt  

Microsoft Academic Search

The occurrence of gas in salt mines and caverns has presented some serious problems to facility operators. Salt mines have long experienced sudden, usually unexpected expulsions of gas and salt from a production face, commonly known as outbursts. Outbursts can release over one million cubic feet of methane and fractured salt, and are responsible for the lives of numerous miners

Brian Ehgartner; Jim Neal; Tom Hinkebein

1998-01-01

349

Containerless processing and rapid solidification of Nb-Si alloys in the niobium-rich eutectic range  

Microsoft Academic Search

Containerless processing and rapid solidification techniques were used to process Nb-Si alloys in the Nb-rich eutectic range. Electromagnetic ally levitated drops were melted and subsequently splat quenched from different temperatures. A variety of eutectic morphologies was obtained as a function of the degree of superheating or undercooling of the drops prior to splatting. Metallic glass was observed only in drops

G. A. Bertero; W. H. Hofmeister; M. B. Robinson; R. J. Bayuzick

1991-01-01

350

Interaction Between Eutectic Intermetallic Particles and Dispersoids in the 3003 Aluminum Alloy During Homogenization Treatments  

NASA Astrophysics Data System (ADS)

The transformation of primary eutectic Al6(Mn,Fe) intermetallics into ?-Al(Mn,Fe)Si and the precipitation of dispersoids were studied in the commercial in the form of 3003 series cast aluminum alloys, mainly under isothermal conditions between 673 K and 873 K (400 C and 600 C). After solidification, both the solid solution and the primary eutectic intermetallics were far from equilibrium. During further heat treatment, the precipitation of fine dispersoids and eutectoid transformation of the primary eutectic particles occurred simultaneously. Having characterized these evolutions under industrial homogenization conditions, the evolution of the microstructure (in terms of its nature, and the quantity, size, and chemical composition of the phases) was characterized during isothermal heat treatment, using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations, quantitative image analysis, and transmission electron microscopy-energy-dispersive spectroscopy (TEM-EDS). The experimental results are analyzed, and changes in chemical composition are discussed and compared with the calculated equilibrium compositions. It is shown that (1) the chemical composition of eutectic intermetallics evolves and tends toward an equilibrium composition; (2) during precipitation, the chemical composition of dispersoids is constant, and close to the expected equilibrium composition when the initial mean composition of the solidification cell is taken into account; (3) after the formation of dispersoids, the quantity of ?-Al(Mn,Fe)Si formed from the initial eutectic intermetallics increased, with the kinetics being controlled by long-range manganese diffusion; and (4) the latter evolution is associated with the dissolution of dispersoids located close to eutectic intermetallics and contributes to the formation of a dispersoid-free zone (DFZ).

Dehmas, M.; Aeby-Gautier, E.; Archambault, P.; Serrire, M.

2013-02-01

351

Internal stresses and the creep resistance of the directionally solidified ceramic eutectics  

Microsoft Academic Search

The creep resistance of the directionally solidified (DS) ceramic eutectic of Al2O3\\/c-ZrO2(Y2O3) was studied in the temperature range of 12001520C. The DS eutectic morphology consists of a topologically continuous majority phase of Al2O3, with a growth texture of [0001] and an encapsulated minority c-ZrO2(Y2O3) phase in a variety of morphologies having a nearly ?112? texture. The two phases are separated

J. Yi; A. S. Argon; A. Sayir

2006-01-01

352

Electrical contact at the interface between silicon and transfer-printed gold films by eutectic joining.  

PubMed

This paper presents the electrical and morphological properties at the interface between a metal (Au) and a semiconductor (Si) formed by a novel transfer-printing technology. This work shows that a transfer-printed thin (hundreds of nanometers) Au film forms excellent electrical contact on a Si substrate when appropriate thermal treatment is applied. The successful electrical contact is attributed to eutectic joining, which allows for the right amount of atomic level mass transport between Au and Si. The outcomes suggest that transfer-printing-based micromanufacturing can realize not only strong mechanical bonding but also high-quality electrical contact via eutectic joining. PMID:23751269

Keum, Hohyun; Chung, Hyun-Joong; Kim, Seok

2013-06-20

353

Microstructural Evolution and Mechanical Proerties of Ti(Ni, Fe)Sn Ultrafine Eutectic Alloys  

Microsoft Academic Search

Ultrafine eutectic alloys have been developed in Ti-Ni, Ti-Fe and Ti-(Ni, Fe)-Sn alloys. The Ti76Ni24 and (Ti74Ni26)97Sn3 ultrafine eutectic alloys consist of a mixture of alpha-Ti and Ti2Ni phases, and beta-Ti(Sn) and Ti2Ni phases, respectively, whereas the Ti70.5Fe29.5 and (Ti70.5Fe29.5)97Sn3 alloys are composed by a mixture of beta-Ti(Sn) and FeTi phases with relatively spherical colony. The compression tests of Ti76Ni24,

Dong Hyouk Pi; Ki Buem Kim; Jin Man Park; Jun Hee Han; Do Hyang Kim

2009-01-01

354

Numerical study: Iron corrosion-resistance in lead-bismuth eutectic coolant by molecular dynamics method  

NASA Astrophysics Data System (ADS)

In this present work, we report numerical results of iron (cladding) corrosion study in interaction with lead-bismuth eutectic coolant of advanced nuclear reactors. The goal of this work is to study how the oxygen can be used to reduce the corrosion rate of cladding. The molecular dynamics method was applied to simulate corrosion process. By evaluating the diffusion coefficients, RDF functions, MSD curves of the iron and also observed the crystal structure of iron before and after oxygen injection to the coolant then we concluded that a significant and effective reduction can be achieved by issuing about 2% number of oxygen atoms to lead-bismuth eutectic coolant.

Arkundato, Artoto; Su'ud, Zaki; Abdullah, Mikrajuddin; Widayani; Celino, Massimo

2012-06-01

355

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

NASA Astrophysics Data System (ADS)

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.

Misra, Ajay K.; Whittenberger, J. Daniel

356

Numerical study of the effect of the shape of the phase diagram on the eutectic freezing temperature  

NASA Astrophysics Data System (ADS)

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.

Ode, M.; Sasajima, N.; Yamada, Y.; Bloembergen, P.; Shimono, M.

2013-09-01

357

Photovoltaic performance of dye sensitized solar cell based on rutile TiO 2 scaffold electrode prepared by a 2 step bi-layer process using molten salt matrices  

Microsoft Academic Search

Dye sensitized solar cells were made on TiO2 scaffold anodes of rutile particles. These TiO2 scaffold anodes were grown from rutile seeds by using a molten salt synthesis technique. Different thickness coatings of mixed amorphous titanium hydroxide and NaClKCl eutectic salt mixture on the rutile seeds were heat treated at different temperatures. The rutile whiskers of different aspect ratios were

B. Roy; P. A. Fuierer; S. Aich

2011-01-01

358

Influence of Electric-Current Pulse Treatment on the Formation of Regular Eutectic Morphology in an Al-Si Eutectic Alloy  

NASA Astrophysics Data System (ADS)

This article describes the influence of an electric current pulse (ECP) on the microstructure of an Al-Si eutectic alloy during directional solidification. Experimental results demonstrate that the ECP has a significant effect on the microstructure of the directionally solidified Al-Si eutectic alloy. Application of ECP can increase the number and area percentage of the complex regular structure (CRS). Furthermore, the area of single CRS increases first and then declines with the increase of the ECP density. Analysis results suggest that the change of the CRS is a result of the forced convection caused by Lorentz force and change of temperature gradient induced by the ECP. The growth process of the CRS is discussed.

Zhang, Yunhu; Song, Changjiang; Zhu, Liang; Zheng, Hongxing; Zhong, Honggang; Han, Qingyou; Zhai, Qijie

2011-06-01

359

An Overview of Liquid Fluoride Salt Heat Transport Systems  

SciTech Connect

Heat transport is central to all thermal-based forms of electricity generation. The ever increasing demand for higher thermal efficiency necessitates power generation cycles transitioning to progressively higher temperatures. Similarly, the desire to provide direct thermal coupling between heat sources and higher temperature chemical processes provides the underlying incentive to move toward higher temperature heat transfer loops. As the system temperature rises, the available materials and technology choices become progressively more limited. Superficially, fluoride salts at {approx}700 C resemble water at room temperature being optically transparent and having similar heat capacity, roughly three times the viscosity, and about twice the density. Fluoride salts are a leading candidate heat-transport material at high temperatures. Fluoride salts have been extensively used in specialized industrial processes for decades, yet they have not entered widespread deployment for general heat transport purposes. This report does not provide an exhaustive screening of potential heat transfer media and other high temperature liquids such as alkali metal carbonate eutectics or chloride salts may have economic or technological advantages. A particular advantage of fluoride salts is that the technology for their use is relatively mature as they were extensively studied during the 1940s-1970s as part of the U.S. Atomic Energy Commission's program to develop molten salt reactors (MSRs). However, the instrumentation, components, and practices for use of fluoride salts are not yet developed sufficiently for commercial implementation. This report provides an overview of the current understanding of the technologies involved in liquid salt heat transport (LSHT) along with providing references to the more detailed primary information resources. Much of the information presented here derives from the earlier MSR program. However, technology has evolved over the intervening years, and this report also describes more recently developed technologies such as dry gas seals. This report also provides a high-level, parametric evaluation of LSHT loop performance to allow general intercomparisons between heat-transport fluid options as well as provide an overview of the properties and requirements for a representative loop. A compilation of relevant thermophysical properties of useful fluoride salts is also included for salt heat transport systems. Fluoride salts can be highly corrosive depending on the container materials selected, the salt chemistry, and the operating procedures used. The report includes an overview of the state-of-the-art in reduction-oxidation chemistry control methodologies employed to minimize corrosion issues. Salt chemistry control technology, however, remains at too low a level of understanding for widespread industrial usage. Loop operational issues such as start-up procedures and system freeze-up vulnerability are also discussed. Liquid fluoride salts are a leading candidate heat transport medium for high-temperature applications. This report provides an overview of the current status of liquid salt heat transport technology. The report includes a high-level, parametric evaluation of liquid fluoride salt heat transport loop performance to allow intercomparisons between heat-transport fluid options as well as providing an overview of the properties and requirements for a representative loop. Much of the information presented here derives from the earlier molten salt reactor program and a significant advantage of fluoride salts, as high temperature heat transport media is their consequent relative technological maturity. The report also includes a compilation of relevant thermophysical properties of useful heat transport fluoride salts. Fluoride salts are both thermally stable and with proper chemistry control can be relatively chemically inert. Fluoride salts can, however, be highly corrosive depending on the container materials selected, the salt chemistry, and the operating procedures used. The report also provides an over

Holcomb, David Eugene [ORNL; Cetiner, Mustafa Sacit [ORNL

2010-09-01

360

Low-frequency electrical properties of polycrystalline saline ice and salt hydrates.  

PubMed

We measured the 1 mHz-1 MHz electrical properties of ice-hydrate binary systems formed from solutions of NaCl, CaCl(2), and MgSO(4), with supplementary measurements of HCl. Below the eutectic temperature, electrical parameters are well described by mixing models in which hydrate is always the connected phase. Above the eutectic temperature, a salt concentration threshold of approximately 3 mM in the initial solution is required for the unfrozen brine fraction to form interconnected, electrically conductive networks. The dielectric relaxation frequency for saline ice increases with increasing impurity content until Cl(-) reaches saturation. Because there is insufficient H(3)O(+) for charge balance, salt cations must be accommodated interstitially in the ice. Dielectric relaxations near the ice signature were identified for CaCl(2).6H(2)O and MgSO(4).11H(2)O but not for NaCl.2H(2)O. Ionic and L-defect concentrations in salt hydrates up to approximately 10(-4) and 10(-3) per H(2)O molecule, respectively, follow from the electrical properties, Jaccard theory, and the assumption that protonic-defect mobilities are similar to ice. These high defect concentrations-up to a few orders of magnitude greater than saturation values in ice-indicate that intrinsic disruption of hydrogen bonding in salt hydrates is common. PMID:19006262

Grimm, Robert E; Stillman, David E; Dec, Steven F; Bullock, Mark A

2008-12-01

361

Microtexture and macrotexture formation in the containerless solidification of undercooled Ni-18.7 at.% Sn eutectic melts  

SciTech Connect

The microscopic orientations of Ni-18.7 at.% Sn eutectics solidified from undercooled states, in particular, within an individual eutectic colony and among neighboring eutectic colonies, have been measured with respect to the eutectic Ni{sub 3}Sn and Ni phases; this was done using a scanning electron microscope equipped with the electron backscatter diffraction pattern (EBSP) mapping technique. The EBSPs and inverse pole figures indicate that the Ni{sub 3}Sn intermetallic compound is continuous and well oriented whereas the Ni solid solution is discontinuous and randomly oriented within an anomalous eutectic grain. Further examination reveals that although Ni particulates are random from an overall view, most neighboring Ni grains have small misorientations of less than 10 deg . The specific solidification sequence and the effect of released crystallization heat on subsequent crystallization are further considered, which enables the primary Ni phase to segment into individual grains whereas Ni{sub 3}Sn does not due to higher entropy of fusion. A little rotation or floating within the constrained framework of the crystallizing Ni{sub 3}Sn compound may yield small misorientation angles. The discontinuous Ni particulates and continuous Ni{sub 3}Sn network are of great significance in revealing the anomalous eutectic formation. The orientation among independent eutectic colonies is random owing to the random appearance of nuclei throughout the volume of undercooled melts. The macrotextures of pole figures (PFs) of two eutectic phases are also mapped versus melt undercooling, which can be interpreted well when considering the nucleation frequency, variation of eutectic colony size, microtexture within a single eutectic colony, and the overall microstructure evolution as a function of melt undercooling.

Li Mingjun [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Tsukuba Space Center, ISS Science Project Office, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan)]. E-mail: li.mingjun@jaxa.jp; Nagashio, Kosuke [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Sagamihara Campus, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan); Ishikawa, Takehiko [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Tsukuba Space Center, ISS Science Project Office, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan); Yoda, Shinichi [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Tsukuba Space Center, ISS Science Project Office, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan); Kuribayashi, Kazuhiko [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Sagamihara Campus, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan)

2005-02-01

362

Potentiometric Sensor for Real-Time Monitoring of Multivalent Ion Concentrations in Molten Salt  

SciTech Connect

Electrorefining of spent metallic nuclear fuel in high temperature molten salt systems is a core technology in pyroprocessing, which in turn plays a critical role in the development of advanced fuel cycle technologies. In electrorefining, spent nuclear fuel is treated electrochemically in order to effect separations between uranium, noble metals, and active metals, which include the transuranics. The accumulation of active metals in a lithium chloride-potassium chloride (LiCl-KCl) eutectic molten salt electrolyte occurs at the expense of the UCl3-oxidant concentration in the electrolyte, which must be periodically replenished. Our interests lie with the accumulation of active metals in the molten salt electrolyte. The real-time monitoring of actinide concentrations in the molten salt electrolyte is highly desirable for controlling electrochemical operations and assuring materials control and accountancy. However, real-time monitoring is not possible with current methods for sampling and chemical analysis. A new solid-state electrochemical sensor is being developed for real-time monitoring of actinide ion concentrations in a molten salt electrorefiner. The ultimate function of the sensor is to monitor plutonium concentrations during electrorefining operations, but in this work gadolinium was employed as a surrogate material for plutonium. In a parametric study, polycrystalline sodium beta double-prime alumina (Na-?-alumina) discs and tubes were subject to vapor-phase exchange with gadolinium ions (Gd3+) using a gadolinium chloride salt (GdCl3) as a precursor to produce gadolinium beta double-prime alumina (Gd-?-alumina) samples. Electrochemical impedance spectroscopy and microstructural analysis were performed on the ion-exchanged discs to determine the relationship between ion exchange and Gd3+ ion conductivity. The ion-exchanged tubes were configured as potentiometric sensors in order to monitor real-time Gd3+ ion concentrations in mixtures of gadolinium chloride (GdCl3) in LiCl-KCl eutectic molten salts through measurement of the potential difference between a reference and working electrode.

Peter A. Zink; Jan-Fong Jue; Brenda E. Serrano; Guy L. Fredrickson; Ben F. Cowan; Steven D. Herrmann; Shelly X. Li

2010-07-01

363

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

NASA Astrophysics Data System (ADS)

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.

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

364

Assembling three-dimensional microstructures using gold-silicon eutectic bonding  

Microsoft Academic Search

An assembly method for three-dimensional microelements is presented. The assembly is done in situ with a micromanipulator in an SEM using Au-Si eutectic bonding. Microblocks bonded to larger silicon substrates are used for evaluation of the mechanical strength and a microarch is presented to demonstrate the possibilities of the technique. The microelements are fabricated by bulk micromachining, and sputter deposited

A.-L. Tiensuu; M. Bexell; J.-. Schweitz; L. Smith; S. Johansson

1994-01-01

365

Directionally Solidified Eutectic Ceramics; In-Situ Composites for High Temperature Structural Applications.  

National Technical Information Service (NTIS)

Eutectics are multiphase structures formed by the cooperative growth of two or more phases. Although the internal structure can vary widely, the development of continuous rods or plates in a matrix can be achieved and, within limits, can be controlled or ...

A. Sayir

2004-01-01

366

Theoretical and numerical study of lamellar eutectic three-phase growth in ternary alloys.  

PubMed

We investigate lamellar three-phase patterns that form during the directional solidification of ternary eutectic alloys in thin samples. A distinctive feature of this system is that many different geometric arrangements of the three phases are possible, contrary to the widely studied two-phase patterns in binary eutectics. Here, we first analyze the case of stable lamellar coupled growth of a symmetric model ternary eutectic alloy, using a Jackson-Hunt-type calculation in thin film geometry, for arbitrary configurations, and derive expressions for the front undercooling as a function of velocity and spacing. Next, we carry out phase-field simulations to test our analytic predictions and to study the instabilities of the simplest periodic lamellar arrays. For large spacings, we observe different oscillatory modes that are similar to those found previously for binary eutectics and that can be classified using the symmetry elements of the steady-state pattern. For small spacings, we observe a new instability that leads to a change in the sequence of the phases. Its onset can be well predicted by our analytic calculations. Finally, some preliminary phase-field simulations of three-dimensional growth structures are also presented. PMID:21728548

Choudhury, Abhik; Plapp, Mathis; Nestler, Britta

2011-05-26

367

On the relation between primary and eutectic solidification structures in gray iron  

NASA Astrophysics Data System (ADS)

The solidification of hypoeutectic gray cast iron starts with the nucleation of primary austenite crystals. Before graphite is nucleated, and the eutectic structure is formed, these crystals start to grow as columnar or equiaxed dendrites. However, very little is known about these dendrites, and especially how they influence the subsequent eutectic structure. Besides, it has previously been shown that the primary solidification structure influences the formation of defects. Shrinkage porosity was found between the dendrites, in the grain boundaries, and the formation of the primary solidification structure was found to influence problems related to metal expansion penetration. Therefore a better understanding about the formation of this structure is of importance. In this work, different inoculants and their influence on the formation of the micro- and macrostructures has been investigated. The inoculants considered are commercially used inoculants, i.e. inoculants used in the foundries, as well as different iron powders. The addition of iron powder is used to promote the primary solidification structure. It is shown that the nucleation of the dendrites is influenced by the amount of iron powder. Secondary dendrite arm spacing is a quantitative measurement in the microstructure related to these dendrites, which in turn depends on the solidification time. Eutectic cell size, on the other hand, is found to depend on secondary dendrite arm spacing. It is shown how the addition of inoculants influences both primary and eutectic solidification structures, and how they are related to each other.

Elmquist, L.; Sonawane, P. A.

2012-01-01

368

Characterization of thermal behavior of deep eutectic solvents and their potential as drug solubilization vehicles.  

PubMed

Deep eutectic solvent (DES) is a new class of solvents typically formed by mixing choline chloride with hydrogen bond donors such as amines, acids, and alcohols. Most DES's are non-reactive with water, biodegradable, and have acceptable toxicity profiles. Urea-choline chloride and malonic acid-choline chloride eutectic systems were characterized using differential scanning calorimetry (DSC) and thermal microscopy. A potential new 2:1 urea-choline chloride cocrystal with a melting point of 25 degrees C was characterized at the eutectic composition. The formation of this cocrystal suggests that DES should not be universally explained by simple eutectic melting, and may be useful in guiding the search for new DES systems. The lack of nucleation of the malonic acid-choline chloride system prohibited the construction of a phase diagram for this system using DSC. We also investigated possible uses of DES in solubilizing poorly soluble compounds for enhanced bioavailability in early drug development such as toxicology studies. For five poorly soluble model compounds, solubility in DES is 5 to 22,000 folds more than that in water. Thus, DES can be a promising vehicle for increasing exposure of poorly soluble compounds in preclinical studies. PMID:19477257

Morrison, Henry G; Sun, Changquan C; Neervannan, Sesha

2009-05-27

369

Preparation, heat treatment, and mechanical properties of the uranium-5 weight percent chromium eutectic alloy  

SciTech Connect

The eutectic alloy of uranium-5 wt % chromium (U-5Cr) was prepared from high-purity materials and cast into 1-in.-thick ingots. This material was given several simple heat treatments, the mechanical properties of these heat-treated samples were determined; and the microstructure was examined. Some data on the melting point and transformation temperatures were obtained.

Townsend, A. B.

1980-10-01

370

Wetting of Cu and Al by Sn-Zn and Zn-Al Eutectic Alloys  

NASA Astrophysics Data System (ADS)

Wetting properties of Sn-Zn and Zn-Al alloys on Cu and Al substrates were studied. Spreading tests were carried out for 3 min, in air and under protective atmosphere of nitrogen, with the use of fluxes. In the case of Zn-Al eutectic, spreading tests were carried out at 460, 480, 500, and 520 C, and in the case of Sn-Zn eutectic at 250, 300, 350, 400, 450, and 500 C, respectively. Solidified solder/substrate couples were cross-sectioned and subjected to microstructure examination. The spreading tests indicated that the wetting properties of eutectic Sn-Zn alloys, on copper pads do not depend on temperature (up to 400 C), but in the lack of protective atmosphere, the solder does not wet the pads. Wettability studies of Zn-Al eutectic on aluminum and copper substrates have shown a negative effect of the protective nitrogen atmosphere on the wetting properties, especially for the copper pads. Furthermore, it was noted that with increasing temperature the solder wettability is improved. In addition, densities of liquid solders were studied by means of dilatometric technique.

Pstru?, Janusz; Fima, Przemys?aw; Gancarz, Tomasz

2012-05-01

371

Refinement of Eutectic Si Phase in Al-5Si Alloys with Yb Additions  

NASA Astrophysics Data System (ADS)

A series of Al-5 wt pct Si alloys with Yb additions (up to 6100 ppm) have been investigated using thermal analysis and multiscale microstructure characterization techniques. The addition of Yb was found to cause no modification effect to a fibrous morphology involving Si twinning; however, a refined plate-like eutectic structure was observed. The Al2Si2Yb phase was observed with Yb addition level of more than 1000 ppm. Within the eutectic Al and Si phases, the Al2Si2Yb phase was also found as a precipitation from the remained liquid. No Yb was detected in the ?-Al matrix or plate-like Si particle, even with Yb addition up to 6100 ppm. The absence of Yb inside the eutectic Si particle may partly explain why no significant Si twinning was observed along {111}Si planes in the eutectic Si particle. In addition, the formation of the thermodynamic stable YbP phases is also proposed to deteriorate the potency of AlP phase in Al alloys. This investigation highlights to distinguish the modification associated with the ever present P in Al alloys. We define modification as a transition from faceted to fibrous morphology, while a reduction of the Si size is termed refinement.

Li, J. H.; Suetsugu, S.; Tsunekawa, Y.; Schumacher, P.

2013-02-01

372

Research on the Mechanism of Thermal Fatigue in Near-Eutectic Pb-Sn Solders.  

National Technical Information Service (NTIS)

This paper discusses the microstructures of solder joints and the mechanisms of thermal fatigue, which is an important source of failure in electronic devices. The solder joints studied were near-eutectic Pb--Sn solder contacts on copper. The microstructu...

J. W. Morris D. Grivas D. Tribula T. Summers D. Frear

1989-01-01

373

Eutectic freeze crystallization: Application to process streams and waste water purification  

Microsoft Academic Search

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

F. van der Ham; G. J. Witkamp; J. de Graauw; G. M. van Rosmalen

1998-01-01

374

Damage by eutectic particle cracking in aluminum casting alloys A356/357  

NASA Astrophysics Data System (ADS)

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.

Wang, Q. G.; Caceres, C. H.; Griffiths, J. R.

2003-12-01

375

Damage by eutectic particle cracking in aluminum casting alloys A356\\/357  

Microsoft Academic Search

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

Q. G. Wang; C. H. Caceres; J. R. Griffiths

2003-01-01

376

MHD technology for the production of Pb-Li eutectic melt with low melting temperature  

Microsoft Academic Search

The lead-based Pb-Li eutectic melt with the low melting temperature has been chosen as a promising blanket material for thermoelectric fusion reactors (for example, in breeding blanket test facilities). The main problem in the production of this material is a great difference in the densities of the both components (Pb and Li). They differ in more than 20 times, therefore,

J. Freibergs; J. Klavins; O. Lielausis; A. Mikelsons; J. Zandarts

2006-01-01

377

Blanket Design Studies of a Lead-Bismuth Eutectic-Cooled Accelerator Transmutation of Waste System  

Microsoft Academic Search

The results of blanket design studies for a lead-bismuth eutectic (LBE)-cooled accelerator transmutation of waste system are presented. These studies focused primarily on achieving two important and somewhat contradictory performance objectives: First, maximizing discharge burnup, so as to minimize the number of successive recycle stages and associated recycle losses, and second, minimizing burnup reactivity loss over an operating cycle, to

Won Sik Yang; Hussein S. Khalil

2001-01-01

378

Microstructural changes induced by ternary additions in a hypo-eutectic titanium-silicon alloy  

Microsoft Academic Search

Hypo-eutectic Ti-6.5 wt % Si alloy modified by separate additions of misch metal and low surface tension elements (Na, Sr, Se and Bi) has been examined by microscopic study and thermal analysis. Addition of third element led to modification of microstructure with apparently no significant enhancement of tensile ductility, with the exception of bismuth. Bismuth enhanced the ductility of the

R. L. Saha; T. K. Nandy; R. D. K. Misra; K. T. Jacob

1991-01-01

379

Lidocaine Iontophoresis Versus Eutectic Mixture of Local Anesthetics (EMLA??) for IV Placement in Children  

Microsoft Academic Search

Pain during venipuncture is a major source of concern to children and their caretakers. Iontophoresis is a novel technique that uses an electrical current to facili- tate movement of solute ions (lidocaine) across the stra- tum corneum barrier to provide dermal analgesia. In this study, we compared dermal analgesia provided by lidocaine iontophoresis and eutectic mixture of local anesthetics (EMLA).

Jeffrey L. Galinkin; John B. Rose; Kathleen Harris; Mehernoor F. Watcha

2002-01-01

380

Eutectic mixtures of capric acid and lauric acid applied in building wallboards for heat energy storage  

Microsoft Academic Search

Capric acid (CA) and lauric acid (LA), as phase change materials (PCM), can be applied for energy storage in low temperature. The phase transition temperature and values of latent heat of eutectic mixtures of CA and LA are suitable for being incorporated with building materials to form phase change wallboards used for building energy storage. 120, 240 and 360 accelerated

Lv Shilei; Zhu Neng; Feng Guohui

2006-01-01

381

Geometry Effects on the Electromigration of Eutectic SN\\/PB Flip-Chip Solder Bumps  

Microsoft Academic Search

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

Dennis H. Eaton; James D. Rowatt; Walter J. Dauksher

2006-01-01

382

Creep-fatigue interaction in eutectic lead-tin solder alloy  

Microsoft Academic Search

A test protocol pivoting about stress cycling where the load waves were trapazoidal and the cycling frequency controlled by balanced time on load and off load was used to determine frequency, mean tensile stress, and compressive stress effects on the creep-fatigue behaviour of the Pb-Sn eutectic solder alloy at ambient temperature. It is consistently found that the minimum creep (or

R. C. Weinbel; J. K. Tien; R. A. Pollak; S. K. Kang

1987-01-01

383

A viscoplastic constitutive model for 63Sn37Pb eutectic solders  

Microsoft Academic Search

Solder joints serve both as electrical and mechanical connections in IC packages and the reliability of solder joints is one of most important issues in electronic packaging. In this study, a new constitutive model for eutectic solders (63Sn37Pb) is proposed. Grain sizes and phase sizes are considered as coarsening is one of the main reasons for solder joint failures. The

Sung Yi; Guangxing Luo; Kerm Sin Chian; W. T. Chen

2000-01-01

384

Design of eutectic photoinitiator blends for UV\\/visible curable acrylated printing inks and coatings  

Microsoft Academic Search

The optimisation of photoinitiator systems used in UV printing inks and coatings has been carried out by means of Design of Experiments (Mixture designs). Mixture designs have been used to improve the reactivity of photoinitiator blends in order to design cost effective, synergistic, near eutectic photoinitiator blends for curing UV printing inks. Both the reactivity and bulk stability of photoinitiator

Juan Segurola; Norman S Allen; Michele Edge; Adam Mc Mahon

1999-01-01

385

AFM and MFM characterization of oxide layers grown on stainless steels in lead bismuth eutectic  

Microsoft Academic Search

Fast reactors and spallation neutron sources may use lead bismuth eutectic (LBE) as a coolant. Its thermal physical and neutronic properties make it a high performance nuclear coolant and spallation target. The main disadvantage of LBE is that it is corrosive to most steels and container materials. Active control of oxygen in LBE will allow the growth of protective oxides

P. Hosemann; M. Hawley; G. Mori; N. Li; S. A. Maloy

2008-01-01

386

CALIBRATION OF YSZ SENSORS FOR THE MEASUREMENT OF OXYGEN CONCENTRATION IN LIQUID Pb-Bi EUTECTIC  

Microsoft Academic Search

Although liquid lead-bismuth eutectic (LBE) is a good candidate for coolant in the subcritical transmutation blanket, it is known to be corrosive to stainless steel, the material of the carrying tubes and containers. Such long- term corrosion problem can be prevented by producing and maintaining a protective oxide layer on the exposed surface of stainless steel. For this purpose, it

Xiaolong Wu; Ramkumar Sivaraman; Ning Li; Wei Hang; T. W. Darling; Yingtao Jiang; Woosoon Yim; Bingmei Fu

387

Twin Astir: An irradiation experiment in liquid PbBi eutectic environment  

Microsoft Academic Search

The Twin Astir irradiation program, currently under irradiation in the BR2 reactor at SCK.CEN is aimed at determining the separate and possibly synergetic effects of a liquid lead bismuth eutectic (LBE) environment and neutron irradiation. It will lead to a parameterisation of the key influencing factors on the mechanical properties of the candidate structural materials for the future experimental accelerator

J. Van den Bosch; A. Al Mazouzi; Ph. Benoit; R. W. Bosch; W. Claes; B. Smolders; P. Schuurmans; H. At Abderrahim

2008-01-01

388

The fabrication of all-silicon micro gas chromatography columns using gold diffusion eutectic bonding  

NASA Astrophysics Data System (ADS)

Temperature programming of gas chromatography (GC) separation columns accelerates the elution rate of chemical species through the column, increasing the speed of analysis, and hence making it a favorable technique to speedup separations in microfabricated GCs (micro-GC). Temperature-programmed separations would be preferred in an all-silicon micro-column compared to a silicon-Pyrex micro-column given that the thermal conductivity and diffusivity of silicon is 2 orders of magnitude higher than Pyrex. This paper demonstrates how to fabricate all-silicon micro-columns that can withstand the temperature cycling required for temperature-programmed separations. The columns were sealed using a novel bonding process where they were first bonded using a gold eutectic bond, then annealed at 1100 C to allow gold diffusion into silicon and form what we call a gold diffusion eutectic bond. The gold diffusion eutectic-bonded micro-columns when examined using scanning electron microscopy (SEM), scanning acoustic microscopy (SAM) and blade insertion techniques showed bonding strength comparable to the previously reported anodic-bonded columns. Gas chromatography-based methane injections were also used as a novel way to investigate proper sealing between channels. A unique methane elution peak at various carrier gas inlet pressures demonstrated the suitability of gold diffusion eutectic-bonded channels as micro-GC columns. The application of gold diffusion eutectic-bonded all-silicon micro-columns to temperature-programmed separations (120 C min-1) was demonstrated with the near-baseline separation of n-C6 to n-C12 alkanes in 35 s.

Radadia, A. D.; Salehi-Khojin, A.; Masel, R. I.; Shannon, M. A.

2010-01-01

389

Natural deep eutectic solvents as new potential media for green technology.  

PubMed

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

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

2013-01-09

390

On the nature of eutectic carbides in Cr-Ni white cast irons  

NASA Astrophysics Data System (ADS)

The mechanical and tribological properties of white cast irons are strongly dependent on whether they contain M7C3 or M3C carbides (M = Fe, Cr, etc.). In an effort to improve the wear resistance of such materials, the United States Bureau of Mines has studied the effects of adding 0.3 to 2.3 wt pct (throughout) Si to hypoeutectic irons containing approximately 8.5 pct Cr and 6.0 pct Ni. The eutectic carbides formed were identified by electron microprobe analysis, X-ray diffraction, and scanning electron (SEM) and optical microscopies. In addition, differential thermal analysis (DTA) was used to study the process of solidification. At Si contents of 0.3 and 1.2 pct, the eutectic carbides exhibited a duplex structure, consisting of cores of M7C3 surrounded by shells of M3C. Additionally, the microstructure contained ledeburite (M3C + ?Fe (austenite)). At the higher Si content of 1.6 pct, the eutectic carbides consisted entirely of M7C3, and some ledeburite remained. Last, when the Si content was raised to 2.3 pct, the eutectic carbides again consisted entirely of M7C3, but ledeburite was no longer formed. These observations can be explained in terms of the effects of Si and, to a lesser extent, of Ni on the shape of the liquidus surface of the metastable Fe-Cr-C phase diagram. The addition of Si reduces the roles played by the four-phase class II p reaction L + M7C3 ? M3C + ?Fe and the ledeburitic eutectic reaction L ? M3C + ?Fe in the overall process of solidification.

Laird, G.; Nielsen, R. L.; MacMillan, N. H.

1991-08-01

391

Reliability of Au-Ge and Au-Si Eutectic Solder Alloys for High-Temperature Electronics  

NASA Astrophysics Data System (ADS)

High-temperature electronics will facilitate deeper drilling, accessing harder-to-reach fossil fuels in oil and gas industry. A key requirement is reliability under harsh conditions for a minimum continuous operating time of 500 h at 300C. Eutectic solder alloys are generally favored due to their excellent fatigue resistance. Performance of Au-Ge and Au-Si eutectic solder alloys at 300C up to 500 h has been evaluated. Nanoindentation results confirm the loss of strength of Au-Ge and Au-Si eutectic solder alloys during thermal aging at 300C, as a result of grain coarsening. However, the pace at which the Au-Ge eutectic alloy loses its strength is much slower when compared with Au-Si eutectic alloy. The interfacial reactions between these eutectic solder alloys and the underbump metallization (UBM), i.e., electroless nickel immersion gold (ENIG) UBM and Cu/Au UBM, have been extensively studied. Spalling of Au3Cu intermetallic compound is observed at the interface between Au-Ge eutectic solder and the Cu/Au UBM, when aged at 300C for 500 h, while the consumption of ENIG UBM is nominal. Unlike the Au-Si solder joint, hot ball shear testing at high temperature confirmed that the Au-Ge joint on ENIG UBM, when aged at 300C for 500 h, could still comply with the minimum qualifying bump shear strength based on the UBM dimension used in this work. Thus, it has been determined that, among these two binary eutectic alloys, Au-Ge eutectic alloy could fulfill the minimum requirement specified by the oil and gas exploration industry.

Chidambaram, Vivek; Yeung, Ho Beng; Shan, Gao

2012-08-01

392

BAM R67: Salts-Phosphate Buffered Saline Solution (Salts ...  

Center for Food Safety and Applied Nutrition (CFSAN)

... BAM R67: Salts-Phosphate Buffered Saline Solution (Salts-PBS). January 2001. ... R67 Salts-Phosphate Buffered Saline Solution (Salts-PBS). ... More results from www.fda.gov/food/foodscienceresearch/laboratorymethods

393

Molten salt electrolyte separator  

DOEpatents

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.

Kaun, Thomas D. (New Lenox, IL)

1996-01-01

394

Temperature effects on thermoelectric properties of A/sup III/B/sup V/-Ge eutectic alloys  

SciTech Connect

The authors have studied the electrophysical properties of eutectic alloys of the systems InSb-Ge, In/sub 0.5/Ga/sub 0.5/Sb-Ge, GaSb-Ge, InAs-Ge, In/sub 0.5/Ga/sub 0.5/As-Ge and, GaAs-Ge at various temperatures and established that the eutectic GaSB-Ge alloy is a good thermoelectric material at 830 K. The effects of doping and temperature on the thermoelectric properties of eutectic alloys differ markedly from their effect on single-phase alloys.

Dement'ev, I.V.; Leonov, V.V.

1988-06-01

395

The surface tension force of anisotropic interphase boundaries is perpendicular to the solidification front during eutectic growth  

NASA Astrophysics Data System (ADS)

The irregular growth dynamics of the so-called locked (tilted) lamellar eutectic grains that are observed in directional solidification of nonfaceted/nonfaceted eutectic alloys, is attributable to a strong surface tension anisotropy of the interphase boundaries, which enters into the local-equilibrium (Young-Herring) condition at the trijunctions of the solid-liquid interfaces. Based on real-time observations of locked eutectic growth in thin samples, we propose that the lamellar tilt angle is selected by the system in such a way that the Hoffmann-Calm surface tension force (vec sigma vector) of the interphase boundaries is approximatively perpendicular to the solidification front.

Bottin-Rousseau, S.; ?erefo?lu, M.; Akamatsu, S.; Faivre, G.

2012-01-01

396

Solidification of high temperature molten salts for thermal energy storage systems  

NASA Astrophysics Data System (ADS)

The solidification of phase change materials for the high temperature thermal energy storage system of an advanced solar thermal power system has been examined theoretically. In light of the particular thermophysical properties of candidate phase change high temperature salts, such as the eutectic mixture of NaF - MgF2, the heat transfer characteristics of one-dimensional inward solidification for a cylindrical geometry have been studied. The Biot number for the solidified salt is shown to be the critical design parameter for constant extraction heat flux. A fin-on-fin design concept of heat transfer surface augmentation is proposed in an effort to minimize the effects of the salt's low thermal conductivity and large volume change upon fusing.

Sheffield, J. W.

1981-06-01

397

Synthesis of oxide perovskite solid solutions using the molten salt method  

SciTech Connect

The molten salt method has in the past been employed to synthesize a large number of compounds at low temperatures. In this work we report the formation of solid solutions of BaTiO{sub 3}{endash}SrTiO{sub 3} and BaZrO{sub 3}{endash}SrZrO{sub 3} using a molten salt eutectic of NaOH{endash}KOH as a solvent. Alkaline earth carbonates and titanium oxide were used as precursors for the titanate system, and alkaline earth carbonates and zirconium oxide were used as precursors for the zirconate system. It was found that both systems form solid solutions throughout the composition range. The implications of these results with regards to the applicability of the molten salt method as a tool to investigate low temperature phase equilibria are discussed. {copyright} {ital 1996 Materials Research Society.}

Gopalan, S.; Mehta, K.; Virkar, A.V. [Department of Materials Science and Engineering, 304 EMRO University of Utah, Salt Lake City, Utah 84112 (United States)

1996-08-01

398

Molten salt test loop  

Microsoft Academic Search

The objective of the Molten Salt Test Loop Project was to design, construct, and demonstrate operation of an outdoor high temperature molten salt test facility. This facility is operational, and can now be used to evaluate materials and components, and the design features and operating procedures required for molten salt heat transport systems. The initial application of the loop was

J. R. Schuster; G. H. Eggers

1980-01-01

399

PLANTS PASS THE SALT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Recently, overexpression of the plasma membrane Na+/H+ antiporter SOS1 was shown to increase salt tolerance of Arabidopsis and revealed that levels of SOS1 mRNA are post-transcriptionally regulated by salt stress. In addition to demonstrating a novel approach to engineer salt-tolerant crops, the res...

400

Sugar and Salt Solutions  

NSDL National Science Digital Library

What happens when sugar and salt are added to water? Pour in sugar, shake in salt, and evaporate water to see the effects on concentration and conductivity. Zoom in to see how different sugar and salt compounds dissolve. Zoom in again to explore the role of water.

Simulations, Phet I.; Lancaster, Kelly; Reid, Sam; Moore, Emily; Chamberlain, Julia; Loeblein, Trish

2011-10-12

401

Plant salt tolerance  

Microsoft Academic Search

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

Jian-Kang Zhu

2001-01-01

402

Viscosity measurement of molten carbonate salt  

Microsoft Academic Search

This report describes research on the eutectic property values of lithium\\/sodium\\/potassium carbonate. This carbonate eutectic is the leading candidate for high-temperature heat transfer fluids for a direct-absorption receiver concept being researched at the Solar Energy Research Institute (SERI) for solar thermal central receiver systems. Measurements of the absolute viscosity of the carbonate eutectic were taken and compared to the results

Janz

1986-01-01

403

Integrated Salt Basin Evaluation  

NASA Astrophysics Data System (ADS)

Salt tectonics plays a major role in the development of many sedimentary basins. Basins containing salt thus frequently display a complex geodynamic evolution characterized by several phases of halokinesis and associated sedimentation. One classic area of salt tectonics is the Central European Basin System (CEBS). Here, the mobile Permian Zechstein salt formed a large number of salt structures such as anticlines, diapirs, pillows, sheets, stocks, and walls during an extended period of salt tectonic activity in Mesozoic and Cenozoic times. Major changes in sedimentation patterns and structural regimes are associated and common in this setting. Increasingly complex subsurface evaluation therefore requires an approach to study salt basins including analogue and numerical models, field studies and laboratory studies which combine seismic, structural and sedimentary studies with analysis of rheological properties, and geomechanic modelling. This concept can be demonstrated using case studies from Permian Salt Basins in Europe and the Late Neoproterozoic to Early Cambrian South Oman Salt Basin. There salt-influenced sedimentary responses to renewed phases of tectonism can be clearly discerned from detailed sequence analysis based on seismic and log data combined with retrodeformation modelling studies. High quality 3-D seismic data integrated with structural modelling improves the definition of the internal dynamics of salt structures and associated sediment architecture in salt-controlled sequences. Paleo-caprocks inside the diapirs point to long phases of dissolution. Salt wedges formed by extrusion and lateral flow of salt glaciers during periods of diapir emergence and reduced sediment accumulation can be accurately modelled. Although salt is widely regarded as a perfect seal, it can become permeable for one- or two-phase fluids under certain conditions of fluid pressure, temperature and deviatoric stress. The fluid pathways can be either along zones of diffuse grain boundary dilatancy, or along open fractures, depending on the fluid overpressure and deviatoric stress.

Kukla, P. A.

2012-04-01

404

Hygroscopic Salts and the Potential for Life on Mars  

NASA Astrophysics Data System (ADS)

Hygroscopic salts have been detected in soils in the northern latitudes of Mars, and widespread chloride-bearing evaporitic deposits have been detected in the southern highlands. The deliquescence of hygroscopic minerals such as chloride salts could provide a local and transient source of liquid water that would be available for microorganisms on the surface. This is known to occur in the Atacama Desert, where massive halite evaporites have become a habitat for photosynthetic and heterotrophic microorganisms that take advantage of the deliquescence of the salt at certain relative humidity (RH) levels. We modeled the climate conditions (RH and temperature) in a region on Mars with chloride-bearing evaporites, and modeled the evolution of the water activity (aw) of the deliquescence solutions of three possible chloride salts (sodium chloride, calcium chloride, and magnesium chloride) as a function of temperature. We also studied the water absorption properties of the same salts as a function of RH. Our climate model results show that the RH in the region with chloride-bearing deposits on Mars often reaches the deliquescence points of all three salts, and the temperature reaches levels above their eutectic points seasonally, in the course of a martian year. The aw of the deliquescence solutions increases with decreasing temperature due mainly to the precipitation of unstable phases, which removes ions from the solution. The deliquescence of sodium chloride results in transient solutions with aw compatible with growth of terrestrial microorganisms down to 252 K, whereas for calcium chloride and magnesium chloride it results in solutions with aw below the known limits for growth at all temperatures. However, taking the limits of aw used to define special regions on Mars, the deliquescence of calcium chloride deposits would allow for the propagation of terrestrial microorganisms at temperatures between 265 and 253 K, and for metabolic activity (no growth) at temperatures between 253 and 233 K.

Davila, Alfonso F.; Duport, Luis Gago; Melchiorri, Riccardo; Jnchen, Jochen; Valea, Sergio; de los Rios, Asuncin; Fairn, Alberto G.; Mhlmann, Diedrich; McKay, Christopher P.; Ascaso, Carmen; Wierzchos, Jacek

2010-08-01

405

Hygroscopic salts and the potential for life on Mars.  

PubMed

Hygroscopic salts have been detected in soils in the northern latitudes of Mars, and widespread chloride-bearing evaporitic deposits have been detected in the southern highlands. The deliquescence of hygroscopic minerals such as chloride salts could provide a local and transient source of liquid water that would be available for microorganisms on the surface. This is known to occur in the Atacama Desert, where massive halite evaporites have become a habitat for photosynthetic and heterotrophic microorganisms that take advantage of the deliquescence of the salt at certain relative humidity (RH) levels. We modeled the climate conditions (RH and temperature) in a region on Mars with chloride-bearing evaporites, and modeled the evolution of the water activity (a(w)) of the deliquescence solutions of three possible chloride salts (sodium chloride, calcium chloride, and magnesium chloride) as a function of temperature. We also studied the water absorption properties of the same salts as a function of RH. Our climate model results show that the RH in the region with chloride-bearing deposits on Mars often reaches the deliquescence points of all three salts, and the temperature reaches levels above their eutectic points seasonally, in the course of a martian year. The a(w) of the deliquescence solutions increases with decreasing temperature due mainly to the precipitation of unstable phases, which removes ions from the solution. The deliquescence of sodium chloride results in transient solutions with a(w) compatible with growth of terrestrial microorganisms down to 252 K, whereas for calcium chloride and magnesium chloride it results in solutions with a(w) below the known limits for growth at all temperatures. However, taking the limits of a(w) used to define special regions on Mars, the deliquescence of calcium chloride deposits would allow for the propagation of terrestrial microorganisms at temperatures between 265 and 253 K, and for metabolic activity (no growth) at temperatures between 253 and 233 K. PMID:20735252

Davila, Alfonso F; Duport, Luis Gago; Melchiorri, Riccardo; Jnchen, Jochen; Valea, Sergio; de Los Rios, Asuncin; Fairn, Alberto G; Mhlmann, Diedrich; McKay, Christopher P; Ascaso, Carmen; Wierzchos, Jacek

406

Some Thermodynamic Aspects of Molten Salts: Halides of Uranium, Zirconium, Thorium, and Cerium in Alkali Halide Eutectics  

Microsoft Academic Search

The technique of thermodynamic studies by means of galvanic cells and ; the processes occurring at working electrodes is described. Measurement of the ; dependence of the reversible, or stationary, electrode upon concentration, ; temperature, current density, and time are described for the systems U\\/UCl; ; Zr\\/ZrCl; Th\\/ThCl; and Ce\\/ CeCl. (W.L.H.);

D. Inman; G. J. Hills; L. Young; J. O'm. Bockris

1960-01-01

407

A study on the recovery of actinide elements from molten LiClKCl eutectic salt by an electrochemical separation  

Microsoft Academic Search

Pyroprocessing is a prominent way for the recovery of the long-lived elements from the spent nuclear fuel. Electrorefining is a key technology for pyroprocessing and generally composed of two recovery stepsdeposition of uranium onto a solid cathode and the recovery of TRU (TRansUranic) elements. In this study, it was investigated on electrochemical separation of actinides to develop an actinide recovery

Sang Woon Kwon; Do Hee Ahn; Eung Ho Kim; Ho Geun Ahn

2009-01-01

408

Separation of Actinides from Rare Earth Elements by Electrorefining in LiC1KC1 Eutectic Salt  

Microsoft Academic Search

A pyrometallurgical partitioning technology to recover actinides from high level radioactive wastes is being developed. In the process, actinides are separated from fission products by electrorefining in molten chloride systems. It is expected that REs (rare earth elements), main components of fission products are hardly separated from actinides. In order to estimate separation factors, electrorefining experiments to recover actinides from

Yoshiharu SAKAMURA; Takatoshi HIJIKATA; Kensuke KINOSHITA; Tadashi INOUE; T. S. STORVICK; C. L. KRUEGER; L. F. GRANTHAM; S. P. FUSSELMAN; D. L. GRIMMETT; J. J. ROY

1998-01-01

409

Electrodeposition of Mg-Li-Al-La Alloys on Inert Cathode in Molten LiCl-KCl Eutectic Salt  

NASA Astrophysics Data System (ADS)

Electrochemical preparation of Mg-Li-Al-La alloys on inert electrodes was investigated in LiCl-KCl melt at 853 K (580 C). Cyclic voltammograms (CVs) and square wave voltammograms (SWVs) show that the existence of AlCl3 or AlF3 could promote La deposition on an active Al substrate, which is predeposited on inert electrodes. All electrochemical tests show that the reduction of La3+ is a one-step reduction process with three electrons exchanged. The reduction of La(III)?La(0) occurred at -2.04 V, and the underpotential deposition (UPD) of La was detected at -1.55 V ( vs Ag/AgCl). The same phenomena concerning La UPD were observed on two inert cathodes, W and Mo. In addition, Mg-Li-Al-La alloys were obtained by galvanostatic electrolysis on the W cathode from La2O3 in LiCl-KCl-MgCl2-KF melts with aluminum as the anode. X-ray diffraction (XRD) measurements indicated that various phases like the Al2La, Al12Mg17, and ?Li phase (LiMg/Li3Mg7) existed in the Mg-Li-Al-La alloys. The distribution of Mg, Al, and La in Mg-Li-Al-La alloys from the analysis of a scan electron micrograph (SEM) and energy dispersive spectrometry (EDS) indicated that the elements Mg, Al, and La distributed homogeneously in the alloys.

Han, Wei; Chen, Qiong; Sun, Yi; Jiang, Tao; Zhang, Milin

2011-12-01

410

Directional solidification, microstructures and mechanical properties of chromium-chromium silicide eutectic alloys  

NASA Astrophysics Data System (ADS)

Alloys based on intermetallics have been considered for high temperature structural applications. However, many of these alloys suffer from intrinsic brittleness and low fracture toughness at ambient temperature. Therefore, ductile phase toughened intermetallic composites are being investigated as a means to improve the fracture toughness. In this study, the Cr-Cr3 Si eutectic system is selected as a model system to investigate composites by directional solidification, where the strong, but brittle Cr3Si is combined with a more ductile Cr-rich solid solution. A series of binary Cr-Si alloys with silicon concentrations ranging from 13 to 24 at.% were produced by arc melting and drop casting. The microstructural investigation suggests that the best composition for obtaining a fully lamellar structure is Cr-16.05 at.% Si, rather than the eutectic composition (Cr-15 at.% Si) indicated in the phase diagram. Uniform and well-aligned lamellar structures were obtained over a fairly wide range of solidification conditions, but not at very low or very high growth rates. The lamellar spacing was found to increase with decreasing solidification rate, in agreement with the Jackson-Hunt theory. In addition, for a fixed growth rate, the lamellar spacing was found to increase with increasing rotation rate. The growth directions in the lamellar eutectic were found to be <100> for the Cr3Si phase and <111> for the Cr solid solution phase. Eutectic microstructures (rod or lamellar) could also be produced at off-eutectic compositions, but only for a limited range of growth conditions. The mechanical properties of the individual lamellae and the Cr-Cr 3Si composites were examined by nanoindentation, Vicker's hardness testing and three-point bend testing. It was found that the Vicker's hardness of Cr-Cr 3Si composites is about HV847, independent of the lamellar spacing. The Young's modulus of the Cr-Cr3Si eutectic composites measured by ultrasonic techniques is 312 GPa. The fracture toughness of single crystals of Cr3Si is very low (2.6 MPa??m). Combination with a more ductile phase (Cr-rich solid solution) to make "ductile phase toughened" composites increases the fracture toughness to maximum 8.5 MPa?m.

Bei, Hongbin

411

A general synthetic method for MPO4 (M = Co, Fe, Mn) frameworks using deep-eutectic solvents.  

PubMed

A general approach was developed to synthesize a series of cobalt, manganese, and iron phosphate frameworks in deep-eutectic solvents through tuning important reaction parameters including temperature, time, and addition of water. PMID:22822488

Yonemoto, Bryan T; Lin, Zhuojia; Jiao, Feng

2012-07-20

412

Automated detection and characterization of microstructural features: application to eutectic particles in single crystal Ni-based superalloys  

NASA Astrophysics Data System (ADS)

Serial sectioning methods continue to produce an abundant amount of image data for quantifying the three-dimensional nature of material microstructures. Here, we discuss a methodology to automate detecting and characterizing eutectic particles taken from serial images of a production turbine blade made of a heat-treated single crystal Ni-based superalloy (PWA 1484). This method includes two important steps for unassisted eutectic particle characterization: automatically identifying a seed point within each particle and segmenting the particle using a region growing algorithm with an automated stop point. Once detected, the segmented eutectic particles are used to calculate microstructural statistics for characterizing and reconstructing statistically representative synthetic microstructures for single crystal Ni-based superalloys. The significance of this work is its ability to automate characterization for analysing the 3D nature of eutectic particles.

Tschopp, M. A.; Groeber, M. A.; Fahringer, R.; Simmons, J. P.; Rosenberger, A. H.; Woodward, C.

2010-03-01

413

High-performance LiCoO 2 by molten salt (LiNO 3:LiCl) synthesis for Li-ion batteries  

Microsoft Academic Search

In an effort to increase and sustain the reversible capacity of LiCoO2 on cycling, LiCoO2 is prepared by using the molten-salt of the eutectic LiNO3LiCl at temperatures 650850C with or without KOH as an oxidizing flux. The compounds are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), chemical analysis, surface area and density techniques. Cathodic behaviour was examined by

K. S. Tan; M. V. Reddy; G. V. Subba Rao; B. V. R. Chowdari

2005-01-01

414

Physical chemistry of molten salt batteries. Final report for period October 1, 1979September 30, 1980. Current-induced composition gradients in molten LiCl-KCl  

Microsoft Academic Search

Current induced composition gradients were demonstrated in the molten LiCl-KCl eutectic mixture, the electrolyte of an LiAl\\/LiCl-KCl\\/FeS\\/sub x\\/ battery. The gradients were produced by electrolysis of the salt between LiAl electrodes at currents of 50 to 100 mA cm⁻², and quenching. Analysis of composition profiles in quenched samples was by atomic absorption spectroscopy, which gave good precision, and by x-ray

J. Braunstein; S. Cantor; C. E. Vallet

1981-01-01

415

Removal of nanoaerosol during the bubbling of the salt melt of beryllium and lithium fluorides for the preparation of reactor radioisotopes  

Microsoft Academic Search

The parameters of aerosol particles formed in the course of the spontaneous thermal condensation of vapors and bubbling a 66LiF-34BeF2 (mol %) eutectic salt mixture with helium have been studied. For this purpose, a vertical bubbling mode at T ≈ 900 K and an ampule device for obtaining reactor radioisotopes for medical applications were used. The rate of the bulk

A. V. Zagnit'ko; D. Yu. Chuvilin

2010-01-01

416

On the stability of boron nitride with lithium alloy electrodes in molten salt cells  

NASA Astrophysics Data System (ADS)

Experiments were carried out to determine the stability of boron nitride separator material in molten salt cells using lithium chloride-potassium chloride (LiCl-KCl) eutectic electrolyte and two stainless steel screen electrodes. The potentials of these electrodes were set by two separate electrical circuits and a lithium-silicon (Li-Si) reservoir electrode. The boron nitride separator was found stable at potentials above -136 mV with respect to a lithium-aluminum reference electrode at 700 K. The separator reacted with lithium and became conductive at potentials more reducing than about -200 mV. Formation of a boride and Li3N led to the conductivity.

Sharma, R. A.; Bradley, T. G.

1981-09-01

417

Low temperature molten-salt synthesis of nanocrystalline cubic Sr 2SbMnO 6  

Microsoft Academic Search

Sr2SbMnO6 (SSM) powders were successfully synthesized at reasonably low temperatures via molten-salt synthesis (MSS) method using eutectic composition of 0.635 Li2SO40.365 Na2SO4 (flux). High-temperature cubic phase SSM was stabilized at room temperature by calcining the as-synthesized powders at 900C\\/10h. The phase formation and morphology of these powders were characterized via X-ray powder diffraction and scanning electron microscopy, respectively. The SSM

Antara Baral; K. B. R. Varma

2009-01-01

418

Compatibility of surface-coated steels, refractory metals and ceramics to high temperature leadbismuth eutectic  

Microsoft Academic Search

Compatibility of cladding material with leadbismuth eutectic at temperature higher than 650C is one of the most crucial issues for feasibility of leadbismuth-cooled fast reactors with cycle efficiency as high as 40%. In order to search for corrosion-resistant materials with leadbismuth eutectic at temperature higher than 650C, surface-coated steels, some refractory metals and various ceramics were tested by means of

Abu Khalid Rivai; Minoru Takahashi

2008-01-01

419

Crystallographic texture in Al 2O 3ZrO 2 (Y 2O 3) directionally solidified eutectics  

Microsoft Academic Search

Directionally solidified Al2O3-based eutectics are in situ composites grown from the melt. The directional nature of the solidification process makes these materials highly anisotropic and therefore the measurement and quantification of their crystallographic texture is necessary to understand their physical properties. We studied the texture of Al2O3ZrO2 (12mol% Y2O3) eutectic rods by means of X-ray and electron backscattering diffraction. The

J. Ramrez-Rico; A. R. de Arellano-Lpez; J. Martnez-Fernndez; J. I. Pea; A. Larrea

2008-01-01

420

Refinement of promising coating compositions for directionally cast eutectics. [Ni19. 7Nb6Cr2. 5Al  

Microsoft Academic Search

The successful application of high creep strength, directionally solidified gamma\\/gamma'-delta (Ni--19.7Nb--6Cr--2.5Al) eutectic superalloy turbine blades requires the development of suitable coatings for airfoil, root and internal blade surfaces. In order to improve coatings for the gamma\\/gamma'-delta alloy, the current investigation had the goals of refining promising coating compositions for directionally solidified eutectics, evaluating the effects of coating\\/substrate interactions on the

T. E. Strangman; E. J. Felten; R. S. Benden

1976-01-01

421

Microstructures and superplastic behavior of eutectic FeC and Ni-Cr white cast irons produced by rapid solidification  

Microsoft Academic Search

Superplastic behavior of two commercial grade white cast irons, eutectic Fe-C and Ni-Cr white cast irons, was investigated at intermediate temperatures (650 to 750 C). For this purpose, rapidly solidified powders of the cast irons were fully consolidated by compaction and rolling at about 650 C. The volume fractions of cementite in the eutectic cast iron and in the Ni-Cr

D. W. Kum; G. Frommeyer; N. J. Grant; O. D. Sherby

1987-01-01

422

The effect of mechanical constraint on the flow and fracture of 63\\/37 Sn\\/Pb eutectic alloy  

Microsoft Academic Search

Copper compact tension specimens containing joints of 63\\/37 Sn\\/Pb eutectic solder alloy are used to study experimentally the flow and fracture behavior of eutectic solder under conditions of monotonic loading and mechanical constraint. Such constraint arises naturally due to the presence of the specimens' copper\\/solder interfaces, and various levels of constraint are achieved by employing joints of various sizes. Concomitant

S. V. Harren; J. Botsis

1995-01-01

423

Containerless processing and rapid solidification of Nb-Si alloys in the niobium-rich eutectic range  

Microsoft Academic Search

Containerless processing and rapid solidification techniques were used to process Nb-Si alloys in the Nb-rich eutectic range.\\u000a Electromagnetic ally levitated drops were melted and subsequently splat quenched from different temperatures. A variety of\\u000a eutectic morphologies was obtained as a function of the degree of superheating or undercooling of the drops prior to splatting.\\u000a Metallic glass was observed only in drops

G. A. Bertero; W. H. Hofmeister; M. B. Robinson; R. J. Bayuzick

1991-01-01

424

Molten salt synthesis of lead lanthanum zirconate titanate ceramic powders  

Microsoft Academic Search

Lead lanthanum zirconate titanate (Pb0.95La0.03)(Zr0.52Ti0.48)O3 (PLZT) was synthesized by one step molten salt method with the starting materials of PbC2O4, La2O3, ZrO(NO3)22H2O and TiO2 in the NaClKCl eutectic mixtures in the temperature range of 7001000C. The single phase of (Pb0.95La0.03)(Zr0.52Ti0.48)O3 powders was prepared at a temperature as low as 850C for 5h. The effects of process parameters, such as soaking

Zongying Cai; Xianran Xing; Lu Li; Yeming Xu

2008-01-01

425

A 2D stochastic micro-macro model of equiaxed eutectic solidification  

NASA Astrophysics Data System (ADS)

We propose a model of equiaxed eutectic solidification that couples macroscopic heat diffusion with a microscopic description of nucleation and growth of the eutectic grains. The heat equation is solved numerically by means of an implicit finite difference method. The evolution of solid fraction is deduced from a stochastic model of nucleation and growth which uses the local temperature (interpolated from the FDM mesh) to determine the local grain density and the local growth rate. The model predicts the evaluations of both temperature and solid fraction at any point of the sample. Moreover, a realistic appearance of the recalescence on the cooling curves, as well as a detailed picture of the microstructure, are predicted. We apply the model to the solidification of grey cast iron.

Charbon, Ch; LeSar, R.

1997-01-01

426

Eutectic bonding of a Ti sputter coated, carbon aerogel wafer to a Ni foil  

SciTech Connect

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.

Jankowski, A.F.; Hayes, J.P.; Kanna, R.L.

1994-06-01

427

Thermodynamic properties of lanthanum in gallium-indium eutectic based alloys  

NASA Astrophysics Data System (ADS)

Activity and activity coefficients of lanthanum were determined for the first time in gallium-indium eutectic based alloys in a wide temperature range employing electromotive force method. Activity of ?-La and super cooled liquid lanthanum in Ga-In eutectic based alloys between 573 and 1073 K linearly depends on the reciprocal temperature:lga=5.660-15,352T0.093 lga=6.074-15,839T0.093 Activity coefficients of ?-La and super cooled liquid lanthanum in this system at 617-1073 K are described by the following equations:lg?=3.786-12,216T0.171 lg?=4.199-12,703T0.171 In addition activity of lanthanum in alloys with In was also determined in the same temperature range.

Shchetinskiy, A. V.; Dedyukhin, A. S.; Volkovich, V. A.; Yamshchikov, L. F.; Maisheva, A. I.; Osipenko, A. G.; Kormilitsyn, M. V.

2013-04-01

428

Study on the melting and freezing behaviour of high temperature binary eutectic fixed points using differential scanning calorimetry  

NASA Astrophysics Data System (ADS)

We have measured the heat flux accompanying the melting or freezing of metal (or metalloid)-carbon eutectics, using differential scanning calorimetry (DSC) to identify appropriate binary systems for secondary thermometry fixed points. Well-known alloy systems such as Fe-C and Ni-C showed reproducible endothermic and exothermic peaks that represent melting and freezing reactions in the DSC measurement. Furthermore, a new Si-C system with a eutectic composition showed reproducible melting and freezing peaks in the DSC measurements. Based on the results by DSC, we identified the Si-SiC eutectic point as a possible eutectic fixed point. To confirm this possibility, we made a Si-SiC cell for thermocouple thermometry and measured its melting and freezing characteristics using a Pt/Pd thermocouple. The melting temperature of the Si-SiC eutectic was reproducible to within 0.02 C (one standard deviation). From the results, we found that Si-SiC has possibility as a new eutectic fixed point at temperatures around 1400 C. We also concluded that DSC analysis could be used to measure the reproducibility of freezing and melting reactions that are to be used as fixed points for thermometry, because it is a rapid and easy-to-use tool for characterizing the thermal behaviour of materials with only a small sample.

Kwon, Su Yong; Kim, Yong-Gyoo; Yang, Inseok

2010-06-01

429

Anodic polarization of stainless steel alloys in molten NaNO3-KNO3 eutectic mixture  

Microsoft Academic Search

This article presents the galvanostatic anodic oxidation of two types of stainless steel alloys, ferritic (15.03% Cr) and austenitic (20.45% Cr, 8.37% Ni), in molten NaNO3-KNO3 eutectic mixture at different temperatures ranging from 673-873K. At a temperature of 673K the shape of polarization curves for the alloys is complex, while at higher temperatures it is simple. The passivity potential range

H. A. Abdel-Hakim Ali; A. A. Attia; A. N. Al-Masri; A. M. Baraka

2001-01-01

430

Nucleation Effect of Ti6Al4V Powder on AlSi Eutectic Alloy  

Microsoft Academic Search

In this research nucleation effect of Ti-6Al-4V powder on grain size and tensile strength of Al-12.1% Si eutectic alloy was studied. Metal powder produced from Ti-6Al-4V machining chips by meshes of 50 and 140 and weight percentages of 0.1, 0.15, 0.2, and 0.25 were used. The microstructure by mesh 50 with 0.15wt% consists of grain with average size of 6m,

Zohair Sarajan

2009-01-01

431

Mechanical behavior of a carbide reinforced Co?Cr eutectic alloy  

Microsoft Academic Search

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\\u000a temperatures to 2200F. The composite was found to be anisotropic with considerable strengthening in the longitudinal direction\\u000a and with the transverse and 45 deg ultimate strengths being limited by

E. R. Thompson; D. A. Koss; J. C. Chesnutt

1970-01-01

432

Crystallography and thermal stability of textured Co-YSZ cermets from eutectic precursors  

Microsoft Academic Search

Textured cubic yttria stabilized zirconia (Co-YSZ) cermets produced by reduction of laser-assisted directionally solidified CoO-YSZ lamellar eutectics presents a microstructure of alternating lamellae of YSZ and porous metal. This microstructure is expected to improve the gas flow, electronic transport and oxygen ions diffusion of the isotropic cermet. Moreover, the cermet presents long-term stability at fuel cell operating temperatures. The stability

M. A. Laguna-Bercero; A. Larrea; R. I. Merino; J. I. Pea; V. M. Orera

2008-01-01

433

Structured porous Ni and Co-YSZ cermets fabricated from directionally solidified eutectic composites  

Microsoft Academic Search

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

M. A. Laguna-Bercero; A. Larrea; J. I. Pea; R. I. Merino; V. M. Orera

2005-01-01

434

Investigation of TiC C Eutectic and WC C Peritectic High-Temperature Fixed Points  

NASA Astrophysics Data System (ADS)

TiC C eutectic (2,761C) and WC C peritectic (2,749C) fixed points were investigated to compare their potential as high-temperature thermometric reference points. Two TiC C and three WC C fixed-point cells were constructed, and the melting and freezing plateaux were evaluated by means of radiation thermometry. The repeatability of the TiC C eutectic within a day was 60 mK with a melting range roughly 200 mK. The repeatability of the melting temperature of the WC C peritectic within 1 day was 17 mK with a melting range of 70 mK. The repeatability of the freezing temperature of the WC C peritectic was 21 mK with a freezing range less than 20 mK. One of the TiC C cells was constructed from a TiC and graphite powder mixture. The filling showed the reaction with the graphite crucible was suppressed and the ingot contained less voids, although the lack of high-purity TiC powder poses a problem. The WC C cells were easily constructed, like metal carbon eutectic cells, without any evident reaction with the crucible. From these results, it is concluded that the WC C peritectic has more potential than the TiC C eutectic as a high-temperature reference point. The investigation of the purification of the TiC C cell during filling and the plateau observation are also reported.

Sasajima, Naohiko; Yamada, Yoshiro

2008-06-01

435

Features of Co\\/C and Ni\\/C eutectic transitions for use in thermocouple thermometry  

Microsoft Academic Search

Eutectic cells of Co\\/C and Ni\\/C for use in thermocouple calibration were manufactured and tested to investigate their melting and freezing characteristics using type B thermocouples. It was observed that the melting and freezing behaviour of Co\\/C and Ni\\/C systems are very similar. The freezing plateaus were found to be flatter than those of melting, but the melting points were

Yong-Gyoo Kim; Inseok Yang; Su Yong Kwon; Kee Sool Gam

2006-01-01

436

Eutectic bonding of austenitic stainless steel 316L to magnesium alloy AZ31 using copper interlayer  

Microsoft Academic Search

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 530C. The bonding process took place through a sequential occurrence of solid-state\\u000a diffusion

Waled M. Elthalabawy; Tahir I. Khan

2011-01-01

437

Enhancement of oxygen transfer in liquid lead and leadbismuth eutectic by natural convection  

Microsoft Academic Search

The present study carries out numerical analysis of the coupled natural convection and oxygen transfer of low-Prandtl-number (?0.02) liquid lead and leadbismuth eutectic (LBE) for testing and calibrating low concentration level oxygen sensors. The analysis is performed on the two-dimensional coordinates in a rectangular container, where the fluid movement is laminar for the purpose of sensor test and calibration. The

Jian Ma; Peng Guo; Jinsuo Zhang; Ning Li; Bingmei M. Fu

2005-01-01

438

Damage by eutectic particle cracking in aluminum casting alloys A356\\/357  

Microsoft Academic Search

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

Q. G. Wang; C. H. Caceres; J. R. Griffiths

2003-01-01

439

The effect of heat transfer on local solidification kinetics of eutectic Al-Si cast alloy  

Microsoft Academic Search

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.

C. Gonzlez-Rivera; M. H. Cruz; H. A. Garca; J. A. Juarez-Islas

1999-01-01

440

Electrochemistry of uranium in ionic organic media: Ethylammonium nitrate and acetamide-KSCN eutectic  

Microsoft Academic Search

The electrochemical reduction of hexavalent and tetravalent uranium is investigated in ethylammonium nitrate at 298 K and in the acetamide-KSCN eutectic at 400 K. The transient techniques describe a two-step reduction of UO\\u000a2\\u000a2+\\u000a in acetamide-KSCN while only one step is observed in ethylammonium nitrate. The reduction of tetravalent uranium proceeds in one step giving trivalent uranium in the

L. Martinot; D. Bar; C. Michaux

1993-01-01

441

Electrochemical studies on the redox mechanism of uranium chloride in molten LiClKCl eutectic  

Microsoft Academic Search

The reduction and oxidation processes on platinum and glassy carbon electrodes in molten LiClKCl eutectic containing UCl3 were investigated by cyclic voltammetry (CV), chronopotentiometry and electrochemical impedance spectroscopy (EIS) in the temperature range 660780K. Two redox peaks have been observed in the cyclic voltammograms corresponding to the two redox reactions U(IV)\\/U(III) and U(III)\\/U which are found to be reversible and

B Prabhakara Reddy; S Vandarkuzhali; T Subramanian; P Venkatesh

2004-01-01

442

Microstructural changes induced by ternary additions in a hypo-eutectic titanium-silicon alloy  

Microsoft Academic Search

Hypo-eutectic Ti-6.5 wt % Si alloy modified by separate additions of misch metal and low surface tension elements (Na, Sr,\\u000a Se and Bi) has been examined by microscopic study and thermal analysis. Addition of third element led to modification of microstructure\\u000a with apparently no significant enhancement of tensile ductility, with the exception of bismuth. Bismuth enhanced the ductility\\u000a of the

R. L. Saha; T. K. Nandy; R. D. K. Misra; K. T. Jacob

1991-01-01

443

Eutectic SnAg solder bump process for ULSI flip chip technology  

Microsoft Academic Search

The novel developed Sn-Ag eutectic solder bump process provides several advantages over conventional solder bump process schemes. Steep wall bumps as plated were fabricated using the nega-type photo resist with a thickness of more than 50 ?m by one time spin coating. This improves productivity for mass production. The 2-step electroplating process was performed using separate plating reactors for Ag

Hirokazu Ezawa; Masahiro Miyata; Soichi Honma; H. Inoue; T. Tokuoka; J. Yoshioka; M. Tsujimura

2000-01-01

444

Eutectic SnAg solder bump process for ULSI flip chip technology  

Microsoft Academic Search

A novel eutectic Pb-free solder bump process, which provides several advantages over conventional solder bump process schemes, has been developed. A thick plating mask can be fabricated for steep wall bumps using a nega-type resist with a thickness of more than 50 ?m by single-step spin coating. This improves productivity for mass production. The two-step electroplating is performed using two

Hirokazu Ezawa; Masahiro Miyata; Soichi Honma; Hiroaki Inoue; Tsuyoshi Tokuoka; Junichiro Yoshioka; Manabu Tsujimura

2001-01-01

445

Microstructural studies of a Ni-W directionally solidified eutectic composite  

Microsoft Academic Search

The influence of heat treatment on the microstructure of a Ni-45.5 wt pct W directionally solidified eutectic composite has\\u000a been studied. Four types of microstructural conditions have been examined using light and thin foil electron microscopy techniques.\\u000a The as-grown composite consists of W fibers in a matrix which contains some WNi4 precipitates. Quenching the composite from above the peritectoid temperature

J. C. Williams; G. Garmong

1975-01-01

446

Lauric and palmitic acids eutectic mixture as latent heat storage material for low temperature heating applications  

Microsoft Academic Search

Palmitic acid (PA, 59.8C) and lauric acid (LA, 42.6C) are phase change materials (PCM) having quite high melting temperatures which can limit their use in low temperature solar applications such as solar space heating and greenhouse heating. However, their melting temperatures can be tailored to appropriate value by preparing a eutectic mixture of the lauric and the palmitic acids. In

Kadir Tunbilek; Ahmet Sari; Sefa Tarhan; Gazanfer Ergne?; Kamil Kaygusuz

2005-01-01

447

Effect of Passivation Opening on Electromigration in Eutectic SnPb Solder Joints  

Microsoft Academic Search

Effect of passivation opening on electromigration in eutectic SnPb solder joints is investigated in this study. Solder bumps were fabricated with a polyimide (PI) and without a PI layer. Both sets of solder joints were subjected to electromigration tests by 0.8A at 150C. Kelvin probes were employed to monitor the increase in bump resistance during electromigration. The bump failure is

F. J. Shen; C. Chen

2008-01-01

448

The effects of Cu doping in eutectic PbSn solder balls on ENIG substrates  

Microsoft Academic Search

Eutectic (63Sn-37Pb) solder balls were doped at varying levels of copper up to 2.0 wt% to determine the effect on the strength of the ball to substrate bond. The test vehicles were fully assembled packages with the Cu-doped solder balls reflowed on electroless nickel immersion gold (ENIG) substrates. Focus is placed on the analysis of the various intermetallic compounds (IMC).

My Nguyen

2005-01-01

449

Electromigration in eutectic SnPb solder bumps with Ni\\/Cu UBM  

Microsoft Academic Search

This study investigates the electromigration behavior of eutectic SnPb solder bumps with Ni\\/Cu UBM, in which the thickness of the Ni and Cu layer is 3 ?m and 5 ?m, respectively. It was found that the SnPb solder joints have better electromigration resistance than that of SnAg bumps with thin film UBM. The thermal characteristic of SnPb solder joints under

Sheng-Hsiang Chiu; Shih-Wei Liang; Chih Chen; S. S. Lin; C. M. Chou; Y. C. Liu; K. H. Chen

2005-01-01

450

Study of electromigration in eutectic SnPb solder stripes using the edge displacement method  

Microsoft Academic Search

Electromigration (EM) parameters in the eutectic SnPb solder were measured using the edge displacement method (EDM) and an\\u000a atomic force microscope (AFM) in the temperature range of 60 to 140C. The measured drift velocity was found to be 0.3 \\/sec\\u000a when the solder stripe was stressed under 4.9104 A\\/cm2 at 80C, and it increased as the current density or the

C. K. Chou; Y. C. Hsu; Chih Chen

2006-01-01

451

Study of electromigration in eutectic SnPb solder stripes using the edge displacement method  

Microsoft Academic Search

Electromigration (EM) parameters in the eutectic SnPb solder were measured using the edge displacement method (EDM) and an atomic force microscope (AFM) in the temperature range of 60 to 140C. The measured drift velocity was found to be 0.3 \\/sec when the solder stripe was stressed under 4.9104 A\\/cm2 at 80C, and it increased as the current density or the

C. K. Chou; Y. C. Hsu; Chih Chen

2006-01-01

452

Strain-rate effects on low cycle fatigue mechanism of eutectic SnPb solder  

Microsoft Academic Search

Low cycle fatigue tests of as-casted SnPb eutectic solder (63Sn\\/37Pb) were carried out using the non-contact strain-controlled system at 20C in order to avoid local deformation and stress concentration at contact points between the extensometer and the specimen surface. The fatigue mechanisms were studied by SEM examination of polished surface of specimens and fracture surfaces. Wedge cracking due to grain

C. Kanchanomai; Y. Miyashita; Y. Mutoh

2002-01-01

453

Creep-fatigue interactions in eutectic tin-lead-based solder alloys. Ph.D. Thesis  

Microsoft Academic Search

Eutectic tin-lead solder alloys subjected to cyclic loading at room temperature experience creep-fatigue interactions due to high homologous temperature. At temperature above 0.5 melting point, the dominant damage mechanism can be cavity nucleation and growth, especially for alloys that have fine grain structure and a large volume fraction of dispersoids. The objective of the present study is to model the

Kuo

1994-01-01

454

Characterization of In-Based Eutectic Alloys Used in Josephson Packaging  

NASA Astrophysics Data System (ADS)

InBiSn and InSn eutectic alloy solders used for Josephson packaging were characterized for the basic understanding of their behavior. Both physical structures and mechanical properties of these solders were studied under various conditions which partly simulate the processing and environmental exposure of these materials. Their interaction with the interface material (Pd/Au) was also probed in an attempt to understand the failure mechanism and to assess the package reliability.

Yeh, James T. C.

1982-09-01

455

Effects of pre-bump probing and bumping processes on eutectic solder bump electromigration  

Microsoft Academic Search

This paper investigates the electromigration reliability of flip chip packages with and without pre-bump wafer probing via high temperature operation life test (HTOL) using printed and electroplated bumps. Under bump metallization (UBM) of printed and electroplated bumps is a thin film of Al\\/Ni(V)\\/Cu and Ti\\/Cu\\/Ni, respectively, while the bump material consists of eutectic Sn\\/Pb solder. Current densities from 7380 to

Kuo-ming Chen; J. D. Wu; Kuo-ning Chiang

2006-01-01

456

Formation of Silicon-Gold Eutectic Bond Using Localized Heating Method  

Microsoft Academic Search

A new bonding technique is proposed by using localized heating to supplythe bonding energy.Heating is achieved by applying a dc current through micromachined heaters made of gold which serves as both the heating and bonding material.At the interface of silicon and gold, the formation of eutectic bond takes place in about 5 minutes.Assembly of two substrates in microfabrication processescan be

Liwei Lin; Yu-Ting Cheng; Khalil Najafi

1998-01-01

457

Phase Diagram of ECDMC Binary System and Enthalpic Determination of Its Eutectic Composition  

Microsoft Academic Search

We construct with a differential scanning calorimeter (DSC) a phase diagram for the ethylene carbonate (EC)-dimethyl carbonate\\u000a (DMC) binary system for its liquid-solid phase equilibria. We determine the eutectic composition of the binary system using\\u000a an enthalpic method that we devised based on the composition dependence of the enthalpy of solidus melting, with highly consistent\\u000a results. We also discuss the

M. S. Ding; K. Xu; T. R. Jow

2000-01-01

458

TEM Study of Bi Segregation in the Interconnect of Eutectic Tin-Bismuth Solder and Copper  

Microsoft Academic Search

The interfacial reaction between eutectic SnBi and Cu was studied by TEM after the sample was reflowed and aged in solid state, respectively. The microstructural evolution at the SnBi\\/Cu interface during reflowed and solid-state aged process was analyzed. The results show that there are two layers of intermetallic compounds (IMCs), Cu3Sn and Cu6Sn5, located at the interface between solder and

P. J. Shang; Z. Q. LiuI; L. Zhang; D. X. Li; J. K. Shang

2007-01-01

459

Spectrophotometric and electrochemical study of neptunium ions in molten NaCl-CsCl eutectic  

NASA Astrophysics Data System (ADS)

The chemical oxidation states of NpO2+, Np4+ and Np3+ in NaCl-CsCl eutectic were controlled by using Cl2, O2, H2 and Ar gas mixtures, the redox behavior and electronic absorption properties of their Np ions were studied. The Np4+ was prepared from NpO2Cl by bubbling Cl2 gas into the melt in the presence of carbon rod. Np3+ was quantitatively prepared by bubbling H2-Ar gas mixture. The molar absorptivities of NpO2+, Np4+ and Np3+ were determined in molten NaCl-CsCl eutectic at 923 K and hypersensitive transitions of Np4+ and Np3+ ions were assigned. Since the polarizing ability of the cations in the NaCl-CsCl eutectic is lower than that in some other melts, it has been shown that the coordination symmetry of the Np-Cl complex is higher.In the electrochemical measurement of Np4+, the cathodic current for the reduction of Np4+ was found to be controlled by the diffusion of Np4+. The temperature dependence of the diffusion coefficient between 823 and 923 K was formulated to be lnD=-4304/T-6.172. The formal redox potential of the Np4+|Np3+ couple depended on the temperature, this dependence was formulated as ENp|Np??=-1.313+6.21010-4TV (vs. Cl2|Cl-).

Uehara, Akihiro; Nagai, Takayuki; Fujii, Toshiyuki; Shirai, Osamu; Yamana, Hajimu

2013-06-01

460

In-situ observation of eutectic growth in Al-based alloys by light microscopy  

NASA Astrophysics Data System (ADS)

An experimental method for the in-situ observation of solidification in eutectic metallic alloys growing at moderate temperatures, i.e. 500-600 C was developed. It is based on unidirectional solidification of thin samples (200 to 700 ?m thick) contained in rectangular quartz glass tubes allowing for in-situ observation of growth on the sample surface by means of light microscopy using a long-distance microscope. The method is illustrated for two-phase eutectic growth in Al-17.5Cu-1.0Ag, Al-11.8Si and Al-11.8Si-0.025Sr as well as for three phase growth in Al-13.3Cu-5.7Si, all at%.Coupled growth of lamellar Al-Al2Cu eutectic in Al-17.5Cu-1.0Ag was investigated in more detail with regard to spacing selection: experiments were performed in a temperature gradient of 381 K cm-1 using different, but constant withdrawal velocities ranging from 0.025 to 1.8 ?m s-1. Measured spacing was compared with literature data and discussed with reference to the Jackson-Hunt theory and the recent amendment proposed by Akamatsu, Faivre, Karma and Plapp. In-situ observations were complemented by post-mortem metallographic analysis using SEM and EBSD in transverse sections.

Witusiewicz, V. T.; Hecht, U.; Rex, S.

2013-06-01

461

The effect of low gold concentrations on the creep of eutectic tin-lead joints  

NASA Astrophysics Data System (ADS)

The effects of low Au concentrations on the creep properties of a eutectic Sn/Pb alloy were investigated. Creep testing was performed on double-shear specimens of fine-grained, eutectic Sn/Pb joints with Au concentrations of 0, 0.2, 1.0, and 1.5 wt pct Au at 90 C, 0, 0.2, and 1.0 wt pct Au at 65C, and 0.2 wt pct Au at 25 C. In the absence of Au, the creep of finegrained eutectic Sn/Pb is dominated by grain-boundary sliding at high homologous temperature and intermediate stress. The addition of 0.2 wt pct Au or more suppressed this mechanism; the high-stress, bulk-creep mechanism was dominant at all stresses tested. Higher concentrations of Au increased porosity within the joints. The porosity decreased joint strength. During failure, the crack path followed softer regions of the joint; cracks propagated through Pb-rich islands or along Sn/Sn grain boundaries.

Kramer, P. A.; Glazer, J.; Morris, J. W.

1994-06-01

462

Free energy barriers for homogeneous crystal nucleation in a eutectic system of binary hard spheres.  

PubMed

In this study, the free energy barriers for homogeneous crystal nucleation in a system that exhibits a eutectic point are computed using Monte Carlo simulations. The system studied is a binary hard sphere mixture with a diameter ratio of 0.85 between the smaller and larger hard spheres. The simulations of crystal nucleation are performed for the entire range of fluid compositions. The free energy barrier is found to be the highest near the eutectic point and is nearly five times that for the pure fluid, which slows down the nucleation rate by a factor of 10(-31). These free energy barriers are some of highest ever computed using simulations. For most of the conditions studied, the composition of the critical nucleus corresponds to either one of the two thermodynamically stable solid phases. However, near the eutectic point, the nucleation barrier is lowest for the formation of the metastable random hexagonal closed packed (rhcp) solid phase with composition lying in the two-phase region of the phase diagram. The fluid to solid phase transition is hypothesized to proceed via formation of a metastable rhcp phase followed by a phase separation into respective stable fcc solid phases. PMID:23656140

Ganagalla, Srinivasa Rao; Punnathanam, Sudeep N

2013-05-01

463

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

NASA Astrophysics Data System (ADS)

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.

Buddhiranon, Sasiwimon; Kyu, Thein

2012-02-01

464

Natural deep eutectic solvents as a new extraction media for phenolic metabolites in Carthamus tinctorius L.  

PubMed

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

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

2013-06-11

465

Brazing characteristics of a Zr-Ti-Cu-Fe eutectic alloy filler metal for Zircaloy-4  

NASA Astrophysics Data System (ADS)

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.

Lee, Jung G.; Lim, C. H.; Kim, K. H.; Park, S. S.; Lee, M. K.; Rhee, C. K.

2013-10-01

466

Plants pass the salt  

Microsoft Academic Search

Recently, overexpression of the plasma membrane Na+\\/H+ antiporter SOS1 was shown to increase salt tolerance of Arabidopsis and revealed that levels of SOS1 mRNA are post-transcriptionally regulated by salt stress. In addition to demonstrating a novel approach to engineer salt-tolerant crops, the results provide the first glimpse of a previously unknown mechanism used by plants to regulate gene expression in

John M. Ward; Kendal D. Hirschi; Heven Sze

2003-01-01

467

Iodised salt is safe.  

PubMed

Iodine deficiency disorders are prevalent in all the States and Union Territories in India. Under the National Iodine Deficiency Disorders control programme, the Government of India has adopted a strategy to iodisation of all edible salt in the country which is a long term and sustainable preventive solution to eliminate iodine deficiency disorders. The benefits to be derived from universal salt iodisation are more to the population. Iodised salt is safe and does not cause any side effect. PMID:8690505

Ranganathan, S

468

Process for depositing salts  

SciTech Connect

A process for depositing a salt by applying an electric current or voltage to at least one pair of electrodes placed in a supersaturated aqueous solution or supercolled molten liquid of an inorganic or organic salt, whereby the supersaturation or supercooling can be broken or prevented and the crystallization or solidification of the salt can be efficiently made. The process of the invention is advantageously utilized in an air-conditioning system.

Kotani, Y.; Kashimoto, T.

1985-07-16

469

The Influence of Cr on the Solidification Behavior of Polycrystalline ?(Ni)/ ?'(Ni3Al)- ?(Ni3Nb) Eutectic Ni-Base Superalloys  

NASA Astrophysics Data System (ADS)

In the current investigation, the effect of Cr on the solidification characteristics and as-cast microstructure of pseudobinary ?- ? eutectic alloys based on a near-eutectic composition (Ni-5.5Al-13.5Nb at. pct) was investigated. It was found that Cr additions promote the formation of a higher volume fraction of ?- ? eutectic microstructure in the interdendritic region. Increasing levels of Cr also triggered morphological changes in the ?- ? eutectic and the formation of ?- ?'- ? ternary eutectic during the last stage of solidification. A detailed characterization of the as-cast alloys also revealed that Cr additions suppressed the liquidus, solidus, and ?' precipitation temperature of these ?/ ?'- ? eutectic alloys. A comparison of the experimental results with thermodynamic calculations using the CompuTherm Pandat database (CompuTherm LLC, Madison, WI) showed qualitative agreement.

Xie, Mengtao; Helmink, Randolph; Tin, Sammy

2012-04-01

470

Impact insensitive dinitromethanide salts.  

PubMed

Several stable guanidinium, triazolium, and tetrazolium dinitromethanide salts with high nitrogen content, good detonation properties, and concomitant low impact sensitivities are potential energetic materials. PMID:24067808

He, Ling; Tao, Guo-Hong; Parrish, Damon A; Shreeve, Jean'ne M

2013-10-01

471

Fabrication of transparent ceramics through melt solidification of near eutectic compositions in HfO 2Al 2O 3GdAlO 3 system  

Microsoft Academic Search

Solidification of eutectic melts in multiple oxide systems can produce directionally solidified eutectic composites by slow cooling, while rapid cooling would give the formation of amorphous phases as super cooled liquids. We have successfully fabricated an amorphous bulk ceramics in the ternary system HfO2Al2O3GdAlO3 for the first time. It has the near eutectic composition of HfO2 (14mol%), Al2O3 (63mol%) and

Shunji Araki; Masahiro Yoshimura

2005-01-01

472

Fabrication of transparent ceramics through melt solidification of near eutectic compositions in HfO 2Al 2O 3GdAlO 3 system  

Microsoft Academic Search

Solidification of eutectic melts in multiple oxide systems can produce directionally solidified eutectic composites by slow cooling, while rapid cooling would give the formation of amorphous phases as super cooled liquids. We have successfully fabricated an amorphous bulk ceramics in the ternary system HfO2Al2O3GdAlO3 for the first time. It has the near eutectic composition of HfO2 (14mol%), Al2O3 (63mol%) and

Shunji Araki; Masahiro Yoshimura

2006-01-01

473

Preparation and Magnetic Property of La 0.7Sr 0.3MnO 3 Nanorod by Combination Sol-Gel with Molten Salt  

Microsoft Academic Search

La0.7Sr0.3MnO3(LSMO) nanorods were synthesized by a method combining sol-gel with molten salts at 950 C for 10 h, which employed KCl+NaCl(mass ratio 4:1) as eutectic molten salts. The morphologies and magnetic properties of the resulting LSMO nanorods were investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), and vibrating sample magnetometer(VSM) measurements. It was found that the obtained perovskite

Shu-yan QI; Jing FENG; Xiao-dong XU; Jing-ping WANG; Xiang-yu HOU; Mi-lin ZHANG

2008-01-01

474

RED Facts: Iron Salts.  

National Technical Information Service (NTIS)

When a pesticide is eligible for reregistration, EPA announces this and explains why in a Reregistration Eligibility Document, or RED. The fact sheet summarizes the information in the RED for iron salts. The iron salts consist of three pesticide active in...

1993-01-01

475

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.

476

Molten salt electrolyte separator  

DOEpatents

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.

Kaun, T.D.

1996-07-09

477

Conservation of salt lakes  

Microsoft Academic Search

Salt lakes have a variety of important uses and values, including especially both economic and scientific ones. These uses and values have been and are increasingly subject to degradation from a variety of impacts: diversion of inflows, pollution, agricultural practices, and introduction of exotic species are among the more important. Recognition of these impacts upon salt lakes has led to

W. D. Williams

1993-01-01

478

A History of Salt  

Microsoft Academic Search

The medical history of salt begins in ancient times and is closely related to different aspects of human history. Salt may be extracted from sea water, mineral deposits, surface encrustations, saline lakes and brine springs. In many inland areas, wood was used as a fuel source for evaporation of brine and this practice led to major deafforestation in central Europe.

Massimo Crillo; Giovambattista Capasso; Vito Andrea Di Leo; Natale Gaspare De Santo

1994-01-01

479

Improving crop salt tolerance  

Microsoft Academic Search

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

T. J. Flowers

2004-01-01

480

Frozen Salt Water  

NSDL National Science Digital Library

In this activity students will investigate what happens to salt water when it freezes. Observations of densities and salt concentration (by measuring conductivity) will be made. These results will be compared with the densities and conductivity conditions found in sea ice cores (columns of frozen sea water taken from the ocean around Antarctica).

Amati Jr., Peter

481

Salt studies: Conclusions  

NASA Astrophysics Data System (ADS)

This report represents the conclusion of the compressed air energy storage (CAES) program in salt. It includes a brief background of salt cavity studies and utilization for CAES, the focuses on long-term stability criteria for solution mined salt cavities. Summary statements are made on some of the more important criteria and their significance for operational peaking-power plants utilizing salt cavities for CAES reservoirs. The concluding section of this report incorporates a discussion of the future for CAES in U.S. salt deposits. This discussion is based mainly on technical considerations, since they have been the main consideration in this particular study. Obviously, economic analyses will dominate decisions by utilities on construction schedules for any technically feasible CAES study.

Thoms, R. L.; Gehle, R. M.

1982-12-01

482

Oral Administration of Decitabine Salt.  

National Technical Information Service (NTIS)

The present invention relates to salts of decitabine as well as methods for synthesizing the salts described herein. Pharmaceutical compositions and methods of using the decitabine salts are also provided, including methods of orally administering the sal...

P. Phiasivongsa S. Redkar

2005-01-01

483

The Role of Interphase Boundaries in the Deformation Behaviour of Fine-Grained Sn-38wt.%Pb Eutectics  

NASA Astrophysics Data System (ADS)

The mechanical properties of binary Sn-38wt.%Pb eutectic alloys in the deformed and annealed states were investigated at room temperature using tensile, micro- and nano-indentation tests. The softening and high plasticity of a deformed Sn-Pb eutectic are explained as a result of grain boundary sliding (GBS) and fast diffusion-driven processes developing along the Sn-Pb interphase boundaries (IBs). From the results of micro- and nano-hardness measurements it follows that the Sn and Pb phases in the annealed eutectic are strengthened, and the relaxation processes occur mainly at the IB. Such IBs in the annealed Sn-Pb eutectic act as barriers to the motion of a dislocation ensemble when the size of the plastic zone is comparable with the grain size, lowering the hardness values due to the development of GBS when more grains are involved in the process of deformation. The nanohardness and elastic modulus values obtained evidence that an IB in the Sn-Pb eutectic is to be considered as a separate phase with its own mechanical properties.

Muktepavela, F.; Bakradze, G.; Zabels, R.

2009-01-01

484

Thermodynamic description and unidirectional solidification of eutectic organic alloys: IV. Binary systems neopentylglycol-succinonitrile and amino-methyl-propanediol-succinonitrile  

SciTech Connect

The temperature and enthalpy of transformations of organic alloys from the binary systems neopentylglycol-succinonitrile (NPG-SCN) and 2-amino-2-methyl-1,3-propanediol-succinonitrile (AMPD-SCN) were measured by means of differential scanning calorimetry (DSC). The phase diagrams of these binary systems were assessed via the CALPHAD approach using Thermo-Calc by simultaneously optimizing the thermodynamic and phase equilibrium data measured in the present work. Proper agreements between the experimental and calculated data for the phase diagrams as well as for the thermochemical properties were achieved. Experiments and calculations show that both the NPG-SCN and the AMPD-SCN systems exhibit a non-variant eutectic reaction with the eutectic point at 90.45 mol% SCN (318.0 K) and at 97.39 mol% SCN (325.7 K), respectively. In the NPG-SCN system the temperature of the eutectic reaction is about 3 K higher than the temperature of the transformation from the ordered crystals (OCs) to the orientationally disordered crystals (ODICs), whereas the eutectic reaction in the AMPD-SCN involves the OCs of AMPD and the ODICs of SCN. Unidirectional solidification experiments were performed with selected NPG-SCN and AMPD-SCN alloys in order to verify phases involved in solid-liquid equilibria and the nature of eutectic growth in these systems. We find that eutectic growth in NPG-SCN eutectic alloy occurs with both solid phases being non-facetted and with a rod-like eutectic structure. The eutectic as well as some hypo-eutectic alloys from the AMPD-SCN system show irregular eutectic growth with a non-facetted BCC{sub A}2 phase of SCN and a facetted monoclinic phase of AMPD.

Witusiewicz, V.T. [Department of Materials and Processes, ACCESS e. V., Intzestrasse 5, D-52072 Aachen (Germany)]. E-mail: victor@access.rwth-aachen.de; Sturz, L. [Department of Materials and Processes, ACCESS e. V., Intzestrasse 5, D-52072 Aachen (Germany); Hecht, U. [Department of Materials and Processes, ACCESS e. V., Intzestrasse 5, D-52072 Aachen (Germany); Rex, S. [Department of Materials and Processes, ACCESS e. V., Intzestrasse 5, D-52072 Aachen (Germany)

2005-01-03

485

Crushed Salt Constitutive Model  

SciTech Connect

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.

Callahan, G.D.

1999-02-01

486

Creep-fatigue interactions in eutectic tin-lead-based solder alloys. Ph.D. Thesis  

SciTech Connect

Eutectic tin-lead solder alloys subjected to cyclic loading at room temperature experience creep-fatigue interactions due to high homologous temperature. At temperature above 0.5 melting point, the dominant damage mechanism can be cavity nucleation and growth, especially for alloys that have fine grain structure and a large volume fraction of dispersoids. The objective of the present study is to model the damage evolution during creep-fatigue interactions and experimentally validate the damage evolution based life predictions in rapidly solidified solder alloys. Four types of solder alloys were considered in this research, namely, conventional 63Sn-37Pb, rapidly solidified 63Sn-37Pb, dispersion-strengthened eut